Science.gov

Sample records for motion control applications

  1. Robotic Compliant Motion Control for Aircraft Refueling Applications

    DTIC Science & Technology

    1988-12-01

    Science in Astronautical Engineering Acceso : or NTIS -; David J. Duvall, B.S. Captain, USAF ................ December, 1988 D,: . 6 Approved for public...discussed techniques for coordinated compliant motion control of multiple ma- nipulators. He also described techniques for handling coupling between...analysis con- sidering only a single degree of freedom, the results were later shown to be equally applicable to a multiple degree of freedom arm (1, p

  2. Towards bioreactor development with physiological motion control and its applications.

    PubMed

    Stoffel, Marcus; Willenberg, Wolfgang; Azarnoosh, Marzieh; Fuhrmann-Nelles, Nadine; Zhou, Bei; Markert, Bernd

    2017-01-01

    In biomedical applications bioreactors are used, which are able to apply mechanical loadings under cultivation conditions on biological tissues. However, complex mechanobiological evolutions, such as the dependency between mechanical properties and cell activity, depend strongly on the applied loading conditions. This requires correct physiological movements and loadings in bioreactors. The aim of the present study is to develop bioreactors, in which native and artificial biological tissues can be cultivated under physiological conditions in knee joints and spinal motion segments. However, in such complex systems, where motions with different degrees of freedom are applied to whole body parts, it is necessary to investigate elements of joints and spinal parts separately. Consequently, two further bioreactors for investigating tendons and cartilage specimens are proposed additionally. The study is complemented by experimental and numerical examples with emphasis on medical and engineering applications, such as biomechanical properties of cartilage replacement materials, injured tendons, and intervertebral discs.

  3. An open architecture motion controller

    NASA Technical Reports Server (NTRS)

    Rossol, Lothar

    1994-01-01

    Nomad, an open architecture motion controller, is described. It is formed by a combination of TMOS, C-WORKS, and other utilities. Nomad software runs in a UNIX environment and provides for sensor-controlled robotic motions, with user replaceable kinematics. It can also be tailored for highly specialized applications. Open controllers such as Nomad should have a major impact on the robotics industry.

  4. On transcending the impasse of respiratory motion correction applications in routine clinical imaging - a consideration of a fully automated data driven motion control framework.

    PubMed

    Kesner, Adam L; Schleyer, Paul J; Büther, Florian; Walter, Martin A; Schäfers, Klaus P; Koo, Phillip J

    2014-12-01

    Positron emission tomography (PET) is increasingly used for the detection, characterization, and follow-up of tumors located in the thorax. However, patient respiratory motion presents a unique limitation that hinders the application of high-resolution PET technology for this type of imaging. Efforts to transcend this limitation have been underway for more than a decade, yet PET remains for practical considerations a modality vulnerable to motion-induced image degradation. Respiratory motion control is not employed in routine clinical operations. In this article, we take an opportunity to highlight some of the recent advancements in data-driven motion control strategies and how they may form an underpinning for what we are presenting as a fully automated data-driven motion control framework. This framework represents an alternative direction for future endeavors in motion control and can conceptually connect individual focused studies with a strategy for addressing big picture challenges and goals.

  5. Two non-contact photoelectric angular position sensors for motion control applications

    NASA Astrophysics Data System (ADS)

    Xu, Tao; Chen, Xiaolu; Bo, Jiang

    2013-01-01

    The angular position sensor can be integrated into most motion control applications where precision monitoring of angular position is required. In order to eliminate mechanical wear of present angular position sensors for determining the rotation orientation, two new non-contact methods utilizing photoelectric switches are proposed and the corresponding sensors are established. One sensor comprises a gravitational ball, one or more light sources and a circular array of photodetectors, and realizes angular position measurement by setting a block between the light source and the corresponding photodetector which is rotated to the lowest point. Another sensor consists of transmitter-receiver sets and an optical encoder. Different from traditional rotary encoder, the transmitter-receiver sets are arranged around the circumference of rotation, and the optical encoder is only one-turn encoder. The concrete configurations of the sensors are described in detail and typical prototypes are illustrated. Both the angular position sensors are non-contact, compact, and low-cost. They can resist harsh environmental conditions such as vibration, excessive ambient temperature, dirt, moisture and dew, so it is especially well-suited for motion control applications.

  6. Viscoelastic model based force control for soft tissue interaction and its application in physiological motion compensation.

    PubMed

    Moreira, Pedro; Zemiti, Nabil; Liu, Chao; Poignet, Philippe

    2014-09-01

    Controlling the interaction between robots and living soft tissues has become an important issue as the number of robotic systems inside the operating room increases. Many researches have been done on force control to help surgeons during medical procedures, such as physiological motion compensation and tele-operation systems with haptic feedback. In order to increase the performance of such controllers, this work presents a novel force control scheme using Active Observer (AOB) based on a viscoelastic interaction model. The control scheme has shown to be stable through theoretical analysis and its performance was evaluated by in vitro experiments. In order to evaluate how the force control scheme behaves under the presence of physiological motion, experiments considering breathing and beating heart disturbances are presented. The proposed control scheme presented a stable behavior in both static and moving environment. The viscoelastic AOB presented a compensation ratio of 87% for the breathing motion and 79% for the beating heart motion.

  7. Establishing motion control in children with autism and intellectual disability: Applications for anatomical and functional MRI.

    PubMed

    Cox, Alison D; Virues-Ortega, Javier; Julio, Flavia; Martin, Toby L

    2017-01-01

    Excessive motion makes magnetic resonance imaging (MRI) extremely challenging among children with autism spectrum disorder (ASD). The medical risks of sedation establish the need for behavioral interventions to promote motion control among children with ASD undergoing MRI scans. We present a series of experiments aimed at establishing both tolerance of the MRI environment and a level of motion control that would be compatible with a successful MRI. During Study 1, we evaluated the effects of prompting and contingent reinforcement on compliance with a sequence of successive approximations to an MRI using a mock MRI. During Study 2, we used prompting and progressive differential reinforcement of other behaviors (DRO) to promote motion control in a mock MRI for increasing periods of time. Finally, during Study 3, some of the participants underwent a real MRI scan while a detailed in-session motion analysis informed the quality of the images captured. © 2016 Society for the Experimental Analysis of Behavior.

  8. Optimal Control of Relative Motion in Arbitrary Fields: Application at Deimos

    NASA Astrophysics Data System (ADS)

    Russell, Ryan P.; Lantoine, Gregory

    2012-06-01

    A second-order, general dynamics, relative motion framework is formulated to solve for optimal finite-burn transfers in complex gravity fields that are not amenable to analytic solutions. The second-order variational equations are employed in a Cartesian frame that is general in fidelity and simple to implement. For a passive chief orbit we show that only 16 coefficient functions are necessary to accommodate most dynamical environments of interest. We pre-compute and curve-fit the coefficient functions which represent the time-varying Jacobians and Hessians of the state equations evaluated along the chief orbit. Once the coefficient functions are evaluated, the resulting CUrve-fit quadRatic Variational Equations ( CURVE) model is almost transparent to the fidelity level and therefore is well suited for the repeated iterations required by nonlinear optimization. The optimal control problem is solved using a robust, second-order technique that is a variant of differential dynamic programming. The model and optimal rendezvous problems are demonstrated in the highly perturbed dynamical environment of the Martian moon Deimos. The resulting implementation is useful for any relative motion application requiring optimal targeting, particularly in the context of complex force fields. While intended primarily for exotic destinations such as the Moon, asteroids, comets, and planetary satellites, the CURVE model and optimal control framework can also be useful for Earth orbiters, especially in cases of large eccentricity and high fidelity geopotentials.

  9. Pit disassembly motion control

    SciTech Connect

    Christensen, L.; Pittman, P. C.

    2001-01-01

    A Department of Energy (DOE) Pit Disassembly and Conversion Facility (PDCF) is being designed for the Savannah River Site in South Carolina. The facility will recover plutonium from excess nuclear weapon pits defined in START II and START III treaties. The plutonium will be stored and used to produce mixed oxide reactor fuel at another new DOE facility. Because of radiation dose issues, much of the pit disassembly work and material transfer will be automated. Automated material handling systems will interface with disassembly lathes, conversion reactors that produce oxide for storage, robotic container welding stations, vault retrieval systems, and nondestructive assay (NDA) instrumentation. The goal is to use common motion control hardware for material transfer and possibly common motion controllers for the unique PDCF systems. The latter is complicated by the different directions manufactures are considering for distributed control, such as Firewire, SERCOS, etc., and by the unique control requirements of machines such as lathes compared to controls for an integrated NDA system. The current design approach is to standardize where possible, use network cables to replace wire bundles where possible, but to first select hardware and motion controllers that meet specific machine or process requirements.

  10. Motion stability. Analytical mechanics. Motion control

    NASA Astrophysics Data System (ADS)

    Matrosov, V. M.; Demin, V. G.

    Topics discussed include the optimal control of trajectory ensembles, the stability of orbital systems, the dynamics of gyroscopic systems, the control of linear delay-differential systems, singular perturbations in problems of optimal control, and resonance problems in the theory of motion stability. Also considered are the comparison principle in the dynamics of distributed parameter systems, the development of an integrated walking robot, stability and stabilization in differential games, geometric methods to describe rigid-body dynamics, and spin-stabilized satellites.

  11. Novel coordinates for nonlinear multibody motion with applications to spacecraft dynamics and control

    NASA Astrophysics Data System (ADS)

    Schaub, Hanspeter

    1998-12-01

    Novel sets of attitude coordinates called the Stereographic Parameters (SPs) and configuration quasivelocity coordinates called the Eigenfactor Quasivelocities (EQVs) are discussed. The SPs are generated through stereographic projections of the Euler parameter constraint hypersphere onto hyperplanes. SP sets are non-unique and have distinct alternate sets referred to as shadow sets. They abide by the same differential kinematic equation, but generally display a different singular behavior. Explicit expressions are developed that map the original SP set to the shadow set and thus avoid any singularities. Both symmetric SPs such as the classical and Modified Rodrigues Parameters (MRPs), as well as asymmetric SPs are discussed. A globally asymptotically stable MRP feedback law which tracks any reference trajectory is presented. Both unsaturated and saturated control cases are discussed. Further, an MRP costate switching condition is developed that allows both original and shadow MRPs to be used simultaneously in optimal control problems. The Lagrange equations of motion in terms of the n-dimensional EQV vector are developed. The EQV formulation has an identity mass matrix which results in no matrix inverse being taken in numerical simulations. An explicit expression is presented that incorporates Pfaffian non-holonomic constraints into the EQV formulation without increasing the system order. Unfortunately, the use of EQV in numerical simulations only proved beneficial in selected cases. Generally the computational burden proved too high. However, the EQVs are found to be valuable when used as velocity feedback coordinates. EQV feedback laws have an exponentially decaying kinetic energy, superior performance to traditional state velocity feedback laws and are found to decouple the motion of multi-link robotic systems. The equations of motion and steering laws of spacecraft containing Variable Speed Control Moment Gyroscopes (VSCMGs) are developed. Contrary to classical

  12. Dynamics and control of motion on the ground and in the air with application to biped robots

    NASA Astrophysics Data System (ADS)

    Hemami, H.; Zheng, Y.-F.

    The dynamics of a multi-linkage model of natural or man-made systems with arbitrary holonomic and non-holonomic constraints at the joints are formulated. The formulation is equally applicable to movements on the ground or in the air. Nonlinear control strategies for postural balance and rhythmic motion are presented. A predictive algorithm to compensate for computation or transmission delay is proposed. Digital computer simulations are presented to demonstrate the effectiveness of the control strategy for a five-link three-dimensional biped.

  13. Cognitively inspired reinforcement learning architecture and its application to giant-swing motion control.

    PubMed

    Uragami, Daisuke; Takahashi, Tatsuji; Matsuo, Yoshiki

    2014-02-01

    Many algorithms and methods in artificial intelligence or machine learning were inspired by human cognition. As a mechanism to handle the exploration-exploitation dilemma in reinforcement learning, the loosely symmetric (LS) value function that models causal intuition of humans was proposed (Shinohara et al., 2007). While LS shows the highest correlation with causal induction by humans, it has been reported that it effectively works in multi-armed bandit problems that form the simplest class of tasks representing the dilemma. However, the scope of application of LS was limited to the reinforcement learning problems that have K actions with only one state (K-armed bandit problems). This study proposes LS-Q learning architecture that can deal with general reinforcement learning tasks with multiple states and delayed reward. We tested the learning performance of the new architecture in giant-swing robot motion learning, where uncertainty and unknown-ness of the environment is huge. In the test, the help of ready-made internal models or functional approximation of the state space were not given. The simulations showed that while the ordinary Q-learning agent does not reach giant-swing motion because of stagnant loops (local optima with low rewards), LS-Q escapes such loops and acquires giant-swing. It is confirmed that the smaller number of states is, in other words, the more coarse-grained the division of states and the more incomplete the state observation is, the better LS-Q performs in comparison with Q-learning. We also showed that the high performance of LS-Q depends comparatively little on parameter tuning and learning time. This suggests that the proposed method inspired by human cognition works adaptively in real environments. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  14. High-bandwidth and flexible tracking control for precision motion with application to a piezo nanopositioner

    NASA Astrophysics Data System (ADS)

    Feng, Zhao; Ling, Jie; Ming, Min; Xiao, Xiao-Hui

    2017-08-01

    For precision motion, high-bandwidth and flexible tracking are the two important issues for significant performance improvement. Iterative learning control (ILC) is an effective feedforward control method only for systems that operate strictly repetitively. Although projection ILC can track varying references, the performance is still limited by the fixed-bandwidth Q-filter, especially for triangular waves tracking commonly used in a piezo nanopositioner. In this paper, a wavelet transform-based linear time-varying (LTV) Q-filter design for projection ILC is proposed to compensate high-frequency errors and improve the ability to tracking varying references simultaneously. The LVT Q-filter is designed based on the modulus maximum of wavelet detail coefficients calculated by wavelet transform to determine the high-frequency locations of each iteration with the advantages of avoiding cross-terms and segmenting manually. The proposed approach was verified on a piezo nanopositioner. Experimental results indicate that the proposed approach can locate the high-frequency regions accurately and achieve the best performance under varying references compared with traditional frequency-domain and projection ILC with a fixed-bandwidth Q-filter, which validates that through implementing the LTV filter on projection ILC, high-bandwidth and flexible tracking can be achieved simultaneously by the proposed approach.

  15. Possible applications of the LEAP motion controller for more interactive simulated experiments in augmented or virtual reality

    NASA Astrophysics Data System (ADS)

    Wozniak, Peter; Vauderwange, Oliver; Mandal, Avikarsha; Javahiraly, Nicolas; Curticapean, Dan

    2016-09-01

    Practical exercises are a crucial part of many curricula. Even simple exercises can improve the understanding of the underlying subject. Most experimental setups require special hardware. To carry out e. g. a lens experiments the students need access to an optical bench, various lenses, light sources, apertures and a screen. In our previous publication we demonstrated the use of augmented reality visualization techniques in order to let the students prepare with a simulated experimental setup. Within the context of our intended blended learning concept we want to utilize augmented or virtual reality techniques for stationary laboratory exercises. Unlike applications running on mobile devices, stationary setups can be extended more easily with additional interfaces and thus allow for more complex interactions and simulations in virtual reality (VR) and augmented reality (AR). The most significant difference is the possibility to allow interactions beyond touching a screen. The LEAP Motion controller is a small inexpensive device that allows for the tracking of the user's hands and fingers in three dimensions. It is conceivable to allow the user to interact with the simulation's virtual elements by the user's very hand position, movement and gesture. In this paper we evaluate possible applications of the LEAP Motion controller for simulated experiments in augmented and virtual reality. We pay particular attention to the devices strengths and weaknesses and want to point out useful and less useful application scenarios.

  16. Predictive fuzzy controller for robotic motion control

    SciTech Connect

    Huang, S.J.; Hu, C.F.

    1995-12-31

    A system output prediction strategy incorporated with a fuzzy controller is proposed to manipulate the robotic motion control. Usually, the current position and velocity errors are used to operate the fuzzy logic controller for picking out a corresponding rule. When the system has fast planning speed or time varying behavior, the required tracking accuracy is difficult to achieve by adjusting the fuzzy rules. In order to improve the position control accuracy and system robustness for the industrial application, the current position error in the fuzzy rules look-up table is substituted by the predictive position error of the next step by using the grey predictive algorithm. This idea is implemented on a five degrees of freedom robot. The experimental results show that this fuzzy controller has effectively improve the system performance and achieved the facilitation of fuzzy controller implementation.

  17. Open architecture CMM motion controller

    NASA Astrophysics Data System (ADS)

    Chang, David; Spence, Allan D.; Bigg, Steve; Heslip, Joe; Peterson, John

    2001-12-01

    Although initially the only Coordinate Measuring Machine (CMM) sensor available was a touch trigger probe, technological advances in sensors and computing have greatly increased the variety of available inspection sensors. Non-contact laser digitizers and analog scanning touch probes require very well tuned CMM motion control, as well as an extensible, open architecture interface. This paper describes the implementation of a retrofit CMM motion controller designed for open architecture interface to a variety of sensors. The controller is based on an Intel Pentium microcomputer and a Servo To Go motion interface electronics card. Motor amplifiers, safety, and additional interface electronics are housed in a separate enclosure. Host Signal Processing (HSP) is used for the motion control algorithm. Compared to the usual host plus DSP architecture, single CPU HSP simplifies integration with the various sensors, and implementation of software geometric error compensation. Motion control tuning is accomplished using a remote computer via 100BaseTX Ethernet. A Graphical User Interface (GUI) is used to enter geometric error compensation data, and to optimize the motion control tuning parameters. It is shown that this architecture achieves the required real time motion control response, yet is much easier to extend to additional sensors.

  18. Motion Control of Micro-/Nanomotors.

    PubMed

    Teo, Wei Zhe; Pumera, Martin

    2016-10-10

    As we progress towards employing self-propelled micro-/nanomotors in envisioned applications such as cargo delivery, environmental remediation, and therapeutic treatments, precise control of the micro-/nanomotors direction and their speed is essential. In this Review, major emerging approaches utilized for the motion control of micro-/nanomotors have been discussed, together with the lastest publications describing these approaches. Future studies could incorporate investigations on micro-/nanomotors motion control in a real-world environment in which matrix complexity might disrupt successful manipulation of these small-scale devices. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. RHIC stochastic cooling motion control

    SciTech Connect

    Gassner, D.; DeSanto, L.; Olsen, R.H.; Fu, W.; Brennan, J.M.; Liaw, CJ; Bellavia, S.; Brodowski, J.

    2011-03-28

    Relativistic Heavy Ion Collider (RHIC) beams are subject to Intra-Beam Scattering (IBS) that causes an emittance growth in all three-phase space planes. The only way to increase integrated luminosity is to counteract IBS with cooling during RHIC stores. A stochastic cooling system for this purpose has been developed, it includes moveable pick-ups and kickers in the collider that require precise motion control mechanics, drives and controllers. Since these moving parts can limit the beam path aperture, accuracy and reliability is important. Servo, stepper, and DC motors are used to provide actuation solutions for position control. The choice of motion stage, drive motor type, and controls are based on needs defined by the variety of mechanical specifications, the unique performance requirements, and the special needs required for remote operations in an accelerator environment. In this report we will describe the remote motion control related beam line hardware, position transducers, rack electronics, and software developed for the RHIC stochastic cooling pick-ups and kickers.

  20. Machine learning in motion control

    NASA Technical Reports Server (NTRS)

    Su, Renjeng; Kermiche, Noureddine

    1989-01-01

    The existing methodologies for robot programming originate primarily from robotic applications to manufacturing, where uncertainties of the robots and their task environment may be minimized by repeated off-line modeling and identification. In space application of robots, however, a higher degree of automation is required for robot programming because of the desire of minimizing the human intervention. We discuss a new paradigm of robotic programming which is based on the concept of machine learning. The goal is to let robots practice tasks by themselves and the operational data are used to automatically improve their motion performance. The underlying mathematical problem is to solve the problem of dynamical inverse by iterative methods. One of the key questions is how to ensure the convergence of the iterative process. There have been a few small steps taken into this important approach to robot programming. We give a representative result on the convergence problem.

  1. Machine learning in motion control

    NASA Technical Reports Server (NTRS)

    Su, Renjeng; Kermiche, Noureddine

    1989-01-01

    The existing methodologies for robot programming originate primarily from robotic applications to manufacturing, where uncertainties of the robots and their task environment may be minimized by repeated off-line modeling and identification. In space application of robots, however, a higher degree of automation is required for robot programming because of the desire of minimizing the human intervention. We discuss a new paradigm of robotic programming which is based on the concept of machine learning. The goal is to let robots practice tasks by themselves and the operational data are used to automatically improve their motion performance. The underlying mathematical problem is to solve the problem of dynamical inverse by iterative methods. One of the key questions is how to ensure the convergence of the iterative process. There have been a few small steps taken into this important approach to robot programming. We give a representative result on the convergence problem.

  2. Stereo vision-based tracking of soft tissue motion with application to online ablation control in laser microsurgery.

    PubMed

    Schoob, Andreas; Kundrat, Dennis; Kahrs, Lüder A; Ortmaier, Tobias

    2017-08-01

    Recent research has revealed that image-based methods can enhance accuracy and safety in laser microsurgery. In this study, non-rigid tracking using surgical stereo imaging and its application to laser ablation is discussed. A recently developed motion estimation framework based on piecewise affine deformation modeling is extended by a mesh refinement step and considering texture information. This compensates for tracking inaccuracies potentially caused by inconsistent feature matches or drift. To facilitate online application of the method, computational load is reduced by concurrent processing and affine-invariant fusion of tracking and refinement results. The residual latency-dependent tracking error is further minimized by Kalman filter-based upsampling, considering a motion model in disparity space. Accuracy is assessed in laparoscopic, beating heart, and laryngeal sequences with challenging conditions, such as partial occlusions and significant deformation. Performance is compared with that of state-of-the-art methods. In addition, the online capability of the method is evaluated by tracking two motion patterns performed by a high-precision parallel-kinematic platform. Related experiments are discussed for tissue substitute and porcine soft tissue in order to compare performances in an ideal scenario and in a setup mimicking clinical conditions. Regarding the soft tissue trial, the tracking error can be significantly reduced from 0.72 mm to below 0.05 mm with mesh refinement. To demonstrate online laser path adaptation during ablation, the non-rigid tracking framework is integrated into a setup consisting of a surgical Er:YAG laser, a three-axis scanning unit, and a low-noise stereo camera. Regardless of the error source, such as laser-to-camera registration, camera calibration, image-based tracking, and scanning latency, the ablation root mean square error is kept below 0.21 mm when the sample moves according to the aforementioned patterns. Final

  3. Optimum control forces for multibody systems with intermittent motion

    NASA Technical Reports Server (NTRS)

    Ider, Sitki Kemal; Amirouche, F. M. L.

    1989-01-01

    The objective is to address the continuity of motion when a dynamical system is suddenly subjected to constraint conditions. Motion discontinuity due to the initial constraint violation is avoided by prior control forces that adjust the motion and yield velocity and acceleration consistent at the point of application of the constraint. The optimum control forces are determined for a specified control interval. The method proposed provides an optimum adjustment of the system's motion and assures that the stresses developed at the system components are kept within acceptable limits. The procedures developed will be illustrated making use of inequality constraints applied to obstacle avoidance problems in robotics.

  4. On the motion control of microparticles by means of an electromagnetic field increasing with time for spectroscopic applications

    NASA Astrophysics Data System (ADS)

    Izmailov, A. Ch.

    2017-02-01

    The possibility of controlling the motion of microparticles by means of external electromagnetic fields (nonresonance laser radiation, in particular) that induce potential wells for such particles, which are characterized by fixed spatial distribution but deepen over time to a certain level, are analyzed. It is assumed that the particles are located in high vacuum and are affected by nondissipative external forces. Slowing down of relatively fast particles when they pass through the discussed potential wells is shown. Such slowing down of particles is demonstrated using a nonresonance laser beam with intensity increasing over time as an example. Specific features of particle dynamics in the electromagnetic fields under consideration in the case of a one-dimensional rectangular potential well are studied in detail based on simple analytical relations derived from the fundamental equations of classical mechanics. The methods of particle cooling and localization demonstrated in the present work can substantially increase spectroscopy resolution of various microparticles, including, under certain conditions, atoms and molecules.

  5. In Search of Bibliographic Control for Instructional Motion Picture Films.

    ERIC Educational Resources Information Center

    Coover, Robert W.

    This historical study report describes phases in the development of applicable standards for cataloging instructional motion picture films. Steps leading to the present state of the art are objectively presented, focusing on standards developed to establish bibliographic control of instructional motion picture films, contemporary reaction to such…

  6. Kinematics and Dynamics of Motion Control Based on Acceleration Control

    NASA Astrophysics Data System (ADS)

    Ohishi, Kiyoshi; Ohba, Yuzuru; Katsura, Seiichiro

    The first IEEE International Workshop on Advanced Motion Control was held in 1990 pointed out the importance of physical interpretation of motion control. The software servoing technology is now common in machine tools, robotics, and mechatronics. It has been intensively developed for the numerical control (NC) machines. Recently, motion control in unknown environment will be more and more important. Conventional motion control is not always suitable due to the lack of adaptive capability to the environment. A more sophisticated ability in motion control is necessary for compliant contact with environment. Acceleration control is the key technology of motion control in unknown environment. The acceleration control can make a motion system to be a zero control stiffness system without losing the robustness. Furthermore, a realization of multi-degree-of-freedom motion is necessary for future human assistance. A human assistant motion will require various control stiffness corresponding to the task. The review paper focuses on the modal coordinate system to integrate the various control stiffness in the virtual axes. A bilateral teleoperation is a good candidate to consider the future human assistant motion and integration of decentralized systems. Thus the paper reviews and discusses the bilateral teleoperation from the control stiffness and the modal control design points of view.

  7. Control of joint motion simulators for biomechanical research

    NASA Technical Reports Server (NTRS)

    Colbaugh, R.; Glass, K.

    1992-01-01

    The authors present a hierarchical adaptive algorithm for controlling upper extremity human joint motion simulators. A joint motion simulator is a computer-controlled, electromechanical system which permits the application of forces to the tendons of a human cadaver specimen in such a way that the cadaver joint under study achieves a desired motion in a physiologic manner. The proposed control scheme does not require knowledge of the cadaver specimen dynamic model, and solves on-line the indeterminate problem which arises because human joints typically possess more actuators than degrees of freedom. Computer simulation results are given for an elbow/forearm system and wrist/hand system under hierarchical control. The results demonstrate that any desired normal joint motion can be accurately tracked with the proposed algorithm. These simulation results indicate that the controller resolved the indeterminate problem redundancy in a physiologic manner, and show that the control scheme was robust to parameter uncertainty and to sensor noise.

  8. Control of joint motion simulators for biomechanical research

    NASA Technical Reports Server (NTRS)

    Colbaugh, R.; Glass, K.

    1992-01-01

    The authors present a hierarchical adaptive algorithm for controlling upper extremity human joint motion simulators. A joint motion simulator is a computer-controlled, electromechanical system which permits the application of forces to the tendons of a human cadaver specimen in such a way that the cadaver joint under study achieves a desired motion in a physiologic manner. The proposed control scheme does not require knowledge of the cadaver specimen dynamic model, and solves on-line the indeterminate problem which arises because human joints typically possess more actuators than degrees of freedom. Computer simulation results are given for an elbow/forearm system and wrist/hand system under hierarchical control. The results demonstrate that any desired normal joint motion can be accurately tracked with the proposed algorithm. These simulation results indicate that the controller resolved the indeterminate problem redundancy in a physiologic manner, and show that the control scheme was robust to parameter uncertainty and to sensor noise.

  9. A Programmable System for Motion Control

    NASA Technical Reports Server (NTRS)

    Nowlin, Brent C.

    2003-01-01

    The need for improved flow measurements in the flow path of aeronautics testing facilities has led the NASA Glenn Research Center to develop a new motion control system. The new system is programmable, offering a flexibility unheard of in previous systems. The motion control system is PLC-based, which leads to highly accurate positioning ability, as well as reliability. The user interface is a software-based HMI package, which also adds flexibility to the overall system. The system also has the ability to create and execute motion profiles. This paper discusses the system's operation, control implementation, and experiences.

  10. Security Applications Of Computer Motion Detection

    NASA Astrophysics Data System (ADS)

    Bernat, Andrew P.; Nelan, Joseph; Riter, Stephen; Frankel, Harry

    1987-05-01

    An important area of application of computer vision is the detection of human motion in security systems. This paper describes the development of a computer vision system which can detect and track human movement across the international border between the United States and Mexico. Because of the wide range of environmental conditions, this application represents a stringent test of computer vision algorithms for motion detection and object identification. The desired output of this vision system is accurate, real-time locations for individual aliens and accurate statistical data as to the frequency of illegal border crossings. Because most detection and tracking routines assume rigid body motion, which is not characteristic of humans, new algorithms capable of reliable operation in our application are required. Furthermore, most current detection and tracking algorithms assume a uniform background against which motion is viewed - the urban environment along the US-Mexican border is anything but uniform. The system works in three stages: motion detection, object tracking and object identi-fication. We have implemented motion detection using simple frame differencing, maximum likelihood estimation, mean and median tests and are evaluating them for accuracy and computational efficiency. Due to the complex nature of the urban environment (background and foreground objects consisting of buildings, vegetation, vehicles, wind-blown debris, animals, etc.), motion detection alone is not sufficiently accurate. Object tracking and identification are handled by an expert system which takes shape, location and trajectory information as input and determines if the moving object is indeed representative of an illegal border crossing.

  11. Adaptive Force Control in Compliant Motion

    NASA Technical Reports Server (NTRS)

    Seraji, H.

    1994-01-01

    This paper addresses the problem of controlling a manipulator in compliant motion while in contact with an environment having an unknown stiffness. Two classes of solutions are discussed: adaptive admittance control and adaptive compliance control. In both admittance and compliance control schemes, compensator adaptation is used to ensure a stable and uniform system performance.

  12. Comprehensive Control of Atomic Motion

    NASA Astrophysics Data System (ADS)

    Raizen, Mark G.

    2009-06-01

    Recent work provides a general two-step solution to trapping and cooling of atoms. The first step is magnetic stopping of paramagnetic atoms with the use of a sequence of pulsed fields. The second step is single-photon cooling, which is based on a one-way barrier. This cooling method is related intimately to the historic problem of “Maxwell’s Demon” and subsequent work by L. Szilard. Here, I discuss the connections between single-photon cooling and information entropy. I also outline future application of these methods to fundamental tests with hydrogen isotopes.

  13. Video motion detection for physical security applications

    SciTech Connect

    Matter, J.C.

    1990-01-01

    Physical security specialists have been attracted to the concept of video motion detection for several years. Claimed potential advantages included additional benefit from existing video surveillance systems, automatic detection, improved performance compared to human observers, and cost effectiveness. In recent years significant advances in image processing dedicated hardware and image analysis algorithms and software have accelerated the successful application of video motion detection systems to a variety of physical security applications. Currently Sandia is developing several advanced systems that employ image processing techniques for a broader set of safeguards and security applications. TCATS (Target Cueing and Tracking System) uses a set of powerful, flexible, modular algorithms and software to alarm on purposeful target motion. Custom TCATS hardware optimized for perimeter security applications is currently being evaluated with video input. VISDTA (Video Imaging System for Detection, Tracking, and Assessment) uses some of the same TCATS algorithms and operates with a thermal imager input. In the scan mode, VISDTA detects changes in a scene from the previous image at a given scan point; in the stare mode, VISDTA detects purposeful motion similar to TCATS.

  14. Motion Imagery and Robotics Application Project (MIRA)

    NASA Technical Reports Server (NTRS)

    Grubbs, Rodney P.

    2010-01-01

    This viewgraph presentation describes the Motion Imagery and Robotics Application (MIRA) Project. A detailed description of the MIRA camera service software architecture, encoder features, and on-board communications are presented. A description of a candidate camera under development is also shown.

  15. Terahertz Generation & Vortex Motion Control in Superconductors

    NASA Astrophysics Data System (ADS)

    Nori, Franco

    2005-03-01

    A grand challenge is to controllably generate electromagnetic waves in layered superconducting compounds because of its Terahertz frequency range. We propose [1] four experimentally realizable devices for generating continuous and pulsed THz radiation in a controllable frequency range. We also describe [2-4] several novel devices for controlling the motion of vortices in superconductors, including a reversible rectifier made of a magnetic-superconducting hybrid structure [4]. Finally, we summarize a study [5] of the friction force felt by moving vortices. 1) S. Savel'ev, V. Yampol'skii, A. Rakhmanov, F. Nori, Tunable Terahertz radiation from Josephson vortices, preprint 2) S. Savel'ev and F. Nori, Experimentally realizable devices for controlling the motion of magnetic flux quanta, Nature Mat. 1, 179 (2002) 3) S. Savel'ev, F. Marchesoni, F. Nori, Manipulating small particles, PRL 92, 160602 (2004); B. Zhu, F. Marchesoni, F. Nori, Controlling the motion of magnetic flux quanta, PRL 92, 180602 (2004) 4) J.E. Villegas, et al., Reversible Rectifier that Controls the Motion of Magnetic Flux Quanta, Science 302, 1188 (2003) 5) A. Maeda, et al., Nano-scale friction: kinetic friction of magnetic flux quanta and charge density waves, preprint

  16. Optimal control of spacecraft motion in the Newtonian gravitational field: application of quaternions to describe orbit orientation.

    NASA Astrophysics Data System (ADS)

    Chelnokov, Yu. N.

    1999-08-01

    The problem of rendezvous of a controllable spacecraft with a spacecraft moving along a Keplerian orbit is solved. Four variants of solutions to the problem and specific cases of the problem solution are considered.

  17. Scalable Photogrammetric Motion Capture System "mosca": Development and Application

    NASA Astrophysics Data System (ADS)

    Knyaz, V. A.

    2015-05-01

    Wide variety of applications (from industrial to entertainment) has a need for reliable and accurate 3D information about motion of an object and its parts. Very often the process of movement is rather fast as in cases of vehicle movement, sport biomechanics, animation of cartoon characters. Motion capture systems based on different physical principles are used for these purposes. The great potential for obtaining high accuracy and high degree of automation has vision-based system due to progress in image processing and analysis. Scalable inexpensive motion capture system is developed as a convenient and flexible tool for solving various tasks requiring 3D motion analysis. It is based on photogrammetric techniques of 3D measurements and provides high speed image acquisition, high accuracy of 3D measurements and highly automated processing of captured data. Depending on the application the system can be easily modified for different working areas from 100 mm to 10 m. The developed motion capture system uses from 2 to 4 technical vision cameras for video sequences of object motion acquisition. All cameras work in synchronization mode at frame rate up to 100 frames per second under the control of personal computer providing the possibility for accurate calculation of 3D coordinates of interest points. The system was used for a set of different applications fields and demonstrated high accuracy and high level of automation.

  18. Galvanometer control system design of aerial camera motion compensation

    NASA Astrophysics Data System (ADS)

    Qiao, Mingrui; Cao, Jianzhong; Wang, Huawei; Guo, Yunzeng; Hu, Changchang; Tang, Hong; Niu, Yuefeng

    2015-10-01

    Aerial cameras exist the image motion on the flight. The image motion has seriously affected the image quality, making the image edge blurred and gray scale loss. According to the actual application situation, when high quality and high precision are required, the image motion compensation (IMC) should be adopted. This paper designs galvanometer control system of IMC. The voice coil motor as the actuator has a simple structure, fast dynamic response and high positioning accuracy. Double-loop feedback is also used. PI arithmetic and Hall sensors are used at the current feedback. Fuzzy-PID arithmetic and optical encoder are used at the speed feedback. Compared to conventional PID control arithmetic, the simulation results show that the control system has fast response and high control accuracy.

  19. Damper-controlled switch for SMA motion smoothing

    NASA Astrophysics Data System (ADS)

    Aguayo, Clover; Utter, Brent; Luntz, Jonathan; Gonzalez, Richard; Brei, Diann; Johnson, Nancy L.; Alexander, Paul W.

    2014-04-01

    While the use of SMA-actuated devices continues to grow in many industries, current device limitations pose a challenge to successful adoption for certain classes of applications. SMA-actuated devices typically demonstrate motion with non-constant velocity due to the non-linear thermo-mechanically coupled behavior of SMA material transformation, and motion sensitivity to external factors such as voltage and load. This variation in motion can lead to the perception of poor device quality, limiting SMA-actuated devices to applications hidden from the sight of the product user, or requiring them to be augmented with higher cost controls to improve the motion quality. Therefore, a need exists for simple, passive, low-cost device technologies that enable the designer to prescribe desired motion characteristics with relative insensitivity to fluctuation in operating conditions. This paper presents a Damper Controlled Switch (DCS) mechanism that delivers constant velocity and relative insensitivity to operating conditions when combined with a standard SMA wire actuator. The DCS includes a damper that acts against a spring to open a switch when the velocity exceeds a tunable threshold. To validate the ability of the DCS to provide the desired motion quality, experiments were conducted comparing the normal motion of the SMA actuator to the motion produced when the same actuator was fitted with a DCS prototype. The addition of the DCS produced nearly constant actuator velocity, performing significantly better than the SMA actuator alone. The tunability of the DCS was demonstrated producing a wide range of attainable constant velocities. Finally, a set of experiments explored the DCS's sensitivity to voltage and load, indicating a low sensitivity to a wide range of operating parameters for which the operating limits were identified. The DCS represents a simple, compact technology based on passive, low-cost components, providing a very practical solution that will enable

  20. The AFIT gross motion control project

    NASA Technical Reports Server (NTRS)

    Leahy, M. B., Jr.

    1991-01-01

    The objective of the Gross Motion Control project is to study alternative control approaches that will provide payload invariant high speed trajectory tracking for nonrepetitive motions in free space. The research has concentrated on modifications to the model-based control structure. Development and evaluation is being actively pursued of both adaptive primary (inner loop) and robust secondary (output loop) controllers. In-house developments are compared and contrasted to the techniques proposed by other researchers. The case study for the evaluation is the first three links of a PUMA-560. Incorporating the principals of multiple model adaptive estimation, artificial neural networks, and Lyapunov theory into the model based paradigm has shown the potential for enhanced tracking. Secondary controllers based on Quantitative Feedback Theory, or augmented with auxiliary inputs, significantly improve the robustness to payload variations and unmodeled drive system dynamics. An overview is presented of the different concepts under investigation and a sample is provided of the latest experimental results.

  1. Controlling vortex motion and vortex kinetic friction

    NASA Astrophysics Data System (ADS)

    Nori, Franco; Savel'ev, Sergey

    2006-05-01

    We summarize some recent results of vortex motion control and vortex kinetic friction. (1) We describe a device [J.E. Villegas, S. Savel'ev, F. Nori, E.M. Gonzalez, J.V. Anguita, R. Garcìa, J.L. Vicent, Science 302 (2003) 1188] that can easily control the motion of flux quanta in a Niobium superconducting film on an array of nanoscale triangular magnets. Even though the input ac current has zero average, the resulting net motion of the vortices can be directed along either one direction, the opposite direction, or producing zero net motion. We also consider layered strongly anisotropic superconductors, with no fixed spatial asymmetry, and show [S. Savel'ev, F. Nori, Nature Materials 1 (2002) 179] how, with asymmetric drives, the ac motion of Josephson and/or pancake vortices can provide a net dc vortex current. (2) In analogy with the standard macroscopic friction, we present [A. Maeda, Y. Inoue, H. Kitano, S. Savel'ev, S. Okayasu, I. Tsukada, F. Nori , Phys. Rev. Lett. 94 (2005) 077001] a comparative study of the friction force felt by vortices in superconductors and charge density waves.

  2. Development of DSP and FPGA based 4-axis motion controller

    NASA Astrophysics Data System (ADS)

    He, Shuai; Gao, Xiaorong; Peng, Chaoyong; Zhang, Yu

    2010-08-01

    This paper presents a DSP and FPGA based 4-axis motion controller, which use host PC as the platform. By adopting the strategy of two stage interpolation, the proposed motion controller supports 2-axis circular interpolation and 3-axis linear interpolation, and its maximum output pulse frequency of each axis can be up to 8 MHz. The controlling algorithms, such as improved coarse interpolation based on the time division principle, T-curve and S-curve velocity profile generation and the error compensation for the position loop, are implemented by DSP to ensure the high performance of the proposed motion controller. Meanwhile, the FPGA integrates PCI bus controller, dual port RAM, second-stage interpolation, encoder feedback logic circuit etc., which allows a flexible, compact, low-cost solution for various applications. Experimental results demonstrate that the presented motion controller features the merits such as the good real-time performance and high machining precision, and it can be used for a wide range of applications in numerical control system.

  3. Biquaternion solution of the kinematic control problem for the motion of a rigid body and its application to the solution of inverse problems of robot-manipulator kinematics

    NASA Astrophysics Data System (ADS)

    Chelnokov, Yu. N.

    2013-01-01

    The problem of reducing the body-attached coordinate system to the reference (programmed) coordinate system moving relative to the fixed coordinate system with a given instantaneous velocity screw along a given trajectory is considered in the kinematic statement. The biquaternion kinematic equations of motion of a rigid body in normalized and unnormalized finite displacement biquaternions are used as the mathematical model of motion, and the dual orthogonal projections of the instantaneous velocity screw of the body motion onto the body coordinate axes are used as the control. Various types of correction (stabilization), which are biquaternion analogs of position and integral corrections, are proposed. It is shown that the linear (obtained without linearization) and stationary biquaternion error equations that are invariant under any chosen programmed motion of the reference coordinate system can be obtained for the proposed types of correction and the use of unnormalized finite displacement biquaternions and four-dimensional dual controls allows one to construct globally regular control laws. The general solution of the error equation is constructed, and conditions for asymptotic stability of the programmed motion are obtained. The constructed theory of kinematic control of motion is used to solve inverse problems of robot-manipulator kinematics. The control problem under study is a generalization of the kinematic problem [1, 2] of reducing the body-attached coordinate system to the reference coordinate system rotating at a given (programmed) absolute angular velocity, and the presentedmethod for solving inverse problems of robotmanipulator kinematics is a development of the method proposed in [3-5].

  4. Decentralized digital adaptive control of robot motion

    NASA Technical Reports Server (NTRS)

    Tarokh, M.

    1990-01-01

    A decentralized model reference adaptive scheme is developed for digital control of robot manipulators. The adaptation laws are derived using hyperstability theory, which guarantees asymptotic trajectory tracking despite gross robot parameter variations. The control scheme has a decentralized structure in the sense that each local controller receives only its joint angle measurement to produce its joint torque. The independent joint controllers have simple structures and can be programmed using a very simple and computationally fast algorithm. As a result, the scheme is suitable for real-time motion control.

  5. Sensor motion control and mobile platforms for aquatic remote sensing

    NASA Astrophysics Data System (ADS)

    Bostater, Charles R., Jr.

    2006-09-01

    Modern remote sensing systems used in repetitive environmental monitoring and surveillance applications are used on various platforms. These platforms can be categorized as stationary (fixed) or moving platforms. The sensing systems monitor the ambient environment which also may have inherent motion, such as the water surface with water waves. This is particularly the case for airborne or ship borne sensing of aquatic environments and is true for ground based walking or crawling systems. The time sequential comparison and spatial registration of sensor images, particularly "hyperspectral imagery" requires pixel to pixel registration for science based change and target (or medium) detection applications. These applications require sensor motion control combined with platform motion control. If the pixel sizes are small - on the order of 1 meter to less than 1 mm, then "nano-positioning accuracy" may be necessary for various aspects of the camera or surveillance sensor system, and/or related sensors used to control the moving platform. In this paper and presentation, an overview of converging technologies to sensor motion control and nano-positioning is discussed. The paper and presentation will demonstrate that the technologies converging on this aspect of remote sensing monitoring systems will require professionals with a combination of skills that are not readily available in today's workforce nor taught in educational programs today - especially at the undergraduate level. Thus there is a need to consider new avenues for educating professionals necessary to engineer and apply these converging technologies to important social environmental monitoring and surveillance needs.

  6. Animation control of surface motion capture.

    PubMed

    Tejera, Margara; Casas, Dan; Hilton, Adrian

    2013-12-01

    Surface motion capture (SurfCap) of actor performance from multiple view video provides reconstruction of the natural nonrigid deformation of skin and clothing. This paper introduces techniques for interactive animation control of SurfCap sequences which allow the flexibility in editing and interactive manipulation associated with existing tools for animation from skeletal motion capture (MoCap). Laplacian mesh editing is extended using a basis model learned from SurfCap sequences to constrain the surface shape to reproduce natural deformation. Three novel approaches for animation control of SurfCap sequences, which exploit the constrained Laplacian mesh editing, are introduced: 1) space–time editing for interactive sequence manipulation; 2) skeleton-driven animation to achieve natural nonrigid surface deformation; and 3) hybrid combination of skeletal MoCap driven and SurfCap sequence to extend the range of movement. These approaches are combined with high-level parametric control of SurfCap sequences in a hybrid surface and skeleton-driven animation control framework to achieve natural surface deformation with an extended range of movement by exploiting existing MoCap archives. Evaluation of each approach and the integrated animation framework are presented on real SurfCap sequences for actors performing multiple motions with a variety of clothing styles. Results demonstrate that these techniques enable flexible control for interactive animation with the natural nonrigid surface dynamics of the captured performance and provide a powerful tool to extend current SurfCap databases by incorporating new motions from MoCap sequences.

  7. Research on NC motion controller based on SOPC technology

    NASA Astrophysics Data System (ADS)

    Jiang, Tingbiao; Meng, Biao

    2006-11-01

    With the rapid development of the digitization and informationization, the application of numerical control technology in the manufacturing industry becomes more and more important. However, the conventional numerical control system usually has some shortcomings such as the poor in system openness, character of real-time, cutability and reconfiguration. In order to solve these problems, this paper investigates the development prospect and advantage of the application in numerical control area with system-on-a-Programmable-Chip (SOPC) technology, and puts forward to a research program approach to the NC controller based on SOPC technology. Utilizing the characteristic of SOPC technology, we integrate high density logic device FPGA, memory SRAM, and embedded processor ARM into a single programmable logic device. We also combine the 32-bit RISC processor with high computing capability of the complicated algorithm with the FPGA device with strong motivable reconfiguration logic control ability. With these steps, we can greatly resolve the defect described in above existing numerical control systems. For the concrete implementation method, we use FPGA chip embedded with ARM hard nuclear processor to construct the control core of the motion controller. We also design the peripheral circuit of the controller according to the requirements of actual control functions, transplant real-time operating system into ARM, design the driver of the peripheral assisted chip, develop the application program to control and configuration of FPGA, design IP core of logic algorithm for various NC motion control to configured it into FPGA. The whole control system uses the concept of modular and structured design to develop hardware and software system. Thus the NC motion controller with the advantage of easily tailoring, highly opening, reconfigurable, and expandable can be implemented.

  8. Control Strategies for Guided Collective Motion

    DTIC Science & Technology

    2015-01-30

    using the composite Lyapunov function. We show that the desired location of the center of this circular formation, which is fixed, is obtained by...circular motion by using Lyapunov theory and the LaSalle’s Invariance principle. Achieving a Stationary or Moving Centroid: In this work, we study...control input is decided by using the composite Lyapunov function. We show that the desired location of the center of this circular formation, which

  9. Control Strategies for Guided Collective Motion

    DTIC Science & Technology

    2015-02-27

    and the other control input is decided by using the composite Lyapunov function. We show that the desired location of the center of this circular...stability of the desired collective circular motion by using Lyapunov theory and the LaSalle’s Invariance principle. Achieving a Stationary or...input is decided by using the composite Lyapunov function. We show that the desired location of the center of this circular formation, which is fixed

  10. Position Control of Motion Compensation Cardiac Catheters

    PubMed Central

    Kesner, Samuel B.; Howe, Robert D.

    2011-01-01

    Robotic catheters have the potential to revolutionize cardiac surgery by enabling minimally invasive structural repairs within the beating heart. This paper presents an actuated catheter system that compensates for the fast motion of cardiac tissue using 3D ultrasound image guidance. We describe the design and operation of the mechanical drive system and catheter module and analyze the catheter performance limitations of friction and backlash in detail. To mitigate these limitations, we propose and evaluate mechanical and control system compensation methods, including inverse and model-based backlash compensation, to improve the system performance. Finally, in vivo results are presented that demonstrate that the catheter can track the cardiac tissue motion with less than 1 mm RMS error. The ultimate goal of this research is to create a fast and dexterous robotic catheter system that can perform surgery on the delicate structures inside of the beating heart. PMID:21874124

  11. Motion control of 7-DOF arms: The configuration control approach

    SciTech Connect

    Homayoun Seraji; Long, M.K.; Lee, T.S. . Jet Propulsion Lab.)

    1993-04-01

    Graphics simulation and real-time implementation of configuration control schemes for a redundant 7-DOF Robotics Research arm are described. The arm kinematics and motion control schemes are described briefly. This is then followed by a description of a graphics simulation environment for 7-DOF arm control on the Silicon Graphics IRIS Workstation. Computer simulation results are presented to demonstrate elbow control, collision avoidance, and optimal joint movement as redundancy resolution goals for the 7-DOF arm. The laboratory setup for experimental validation of motion control of the 7-DOF Robotics Research arm is then described. The configuration control approach is implemented on a Motorola 68020/VME bus-based real-time controller, with elbow positioning for redundancy resolution. Experimental results demonstrate the efficacy of configuration control for real-time control of the 7-DOF arm.

  12. Motion control of 7-DOF arms - The configuration control approach

    NASA Technical Reports Server (NTRS)

    Seraji, Homayoun; Long, Mark K.; Lee, Thomas S.

    1993-01-01

    Graphics simulation and real-time implementation of configuration control schemes for a redundant 7-DOF Robotics Research arm are described. The arm kinematics and motion control schemes are described briefly. This is followed by a description of a graphics simulation environment for 7-DOF arm control on the Silicon Graphics IRIS Workstation. Computer simulation results are presented to demonstrate elbow control, collision avoidance, and optimal joint movement as redundancy resolution goals. The laboratory setup for experimental validation of motion control of the 7-DOF Robotics Research arm is then described. The configuration control approach is implemented on a Motorola-68020/VME-bus-based real-time controller, with elbow positioning for redundancy resolution. Experimental results demonstrate the efficacy of configuration control for real-time control.

  13. Development of motion control method for laser soldering process

    SciTech Connect

    Yerganian, S.S.

    1997-05-01

    Development of a method to generate the motion control data for sealing an electronic housing using laser soldering is described. The motion required to move the housing under the laser is a nonstandard application and was performed with a four-axis system using the timed data streaming mode capabilities of a Compumotor AT6400 indexer. A Microsoft Excel 5.0 spreadsheet (named Israuto.xls) was created to calculate the movement of the part under the laser, and macros were written into the spreadsheet to allow the user to easily create this data. A data verification method was developed for simulating the motion data. The geometry of the assembly was generated using Parametric Technology Corporation Pro/E version 15. This geometry was then converted using Pro/DADS version 3.1 from Computer Aided Design Software Inc. (CADSI), and the simulation was carried out using DADS version 8.0 from CADSI.

  14. Model-Based Motion Estimation and Its Application to Restoration and Interpolation of Motion Pictures.

    DTIC Science & Technology

    1987-06-01

    A common example of this problem occurs when motion picture films are shown on a conventional NTSC television system. The motion picture industry...second, or 30 frames per second. In order to show a motion picture film on an NTSC television system, temporal interpolation is necessary. The technique...Application to Restoration and Interpolation of Motion Pictures ", Dennis Michael Martinez Technical Report No. 530 June 1987 DTIO aELECTE SEp 2 3N DWM I

  15. Motion drive system is accurately controlled in the 1-micron range

    NASA Technical Reports Server (NTRS)

    Morecroft, J. H.

    1966-01-01

    Motion drive system has been developed for use with interferometers where accurate control of minuscule distance in the 1-micron range is of prime importance. The drive system is applicable to any device that requires extremely accurate positioning control.

  16. Prosthetic hand control using motion discrimination from EMG signals.

    PubMed

    Kurisu, Naoyuki; Tsujiuchi, Nobutaka; Koizumi, Takayuki

    2009-01-01

    In this report, we improve the motion discrimination method from electromyogram (EMG) for a prosthetic hand and propose prosthetic hand control. In the past, we proved that a motion discrimination method using conic models could discriminate three hand motions without the incorrect discriminations that the elbow motions cause. In this research, to increase discrimination accuracy of motion discrimination using conic models, we propose a feature extraction method using quadratic polynomials. Additionally, because many prosthetic hands using motion discrimination have constant motion speed that can't be controlled, we propose an angular velocity generation method using multiple regression models. We verified these methods by controlling the 3D hand model. In the experiment, the proposed method could discriminate five motions at a rate of above 90 percent without the incorrect discriminations that elbow motions cause. Moreover, the wrist joint angle of the 3D hand model could be controlled by standard variation of 3[deg] or less.

  17. Rapid prototyping of an advanced motion controller

    NASA Astrophysics Data System (ADS)

    Cooper, R. S.

    This paper illustrates how, using existing research material, an advanced motion control system was developed both rapidly and economically. The paper emphasizes the approach used to put the system together, rather than the results of the evaluation (which is still under way). The system consists of a field-oriented controlled (FOC) induction motor, along with a pulse-population modulated current motor drive. Specific areas addressed in this paper include: a thorough overview of the technologies involved in the project (with emphasis on FOC theory); use of advanced simulation tools and models to aid in system design and debug; use of existing systems wherever possible to help speed up development; and developing the system in an environment suited to true development work.

  18. Adaptive Animation of Human Motion for E-Learning Applications

    ERIC Educational Resources Information Center

    Li, Frederick W. B.; Lau, Rynson W. H.; Komura, Taku; Wang, Meng; Siu, Becky

    2007-01-01

    Human motion animation has been one of the major research topics in the field of computer graphics for decades. Techniques developed in this area help present human motions in various applications. This is crucial for enhancing the realism as well as promoting the user interest in the applications. To carry this merit to e-learning applications,…

  19. Adaptive Animation of Human Motion for E-Learning Applications

    ERIC Educational Resources Information Center

    Li, Frederick W. B.; Lau, Rynson W. H.; Komura, Taku; Wang, Meng; Siu, Becky

    2007-01-01

    Human motion animation has been one of the major research topics in the field of computer graphics for decades. Techniques developed in this area help present human motions in various applications. This is crucial for enhancing the realism as well as promoting the user interest in the applications. To carry this merit to e-learning applications,…

  20. A Realization of Motion Copying System Based on Multilateral Control

    NASA Astrophysics Data System (ADS)

    Yokokura, Yuki; Katsura, Seiichiro; Ohishi, Kiyoshi

    This paper proposes a motion copying system in order to reproduce motion of human operators. The motion copying system consists of both motion saving system and motion loading system based on multilateral controller. The motion saving system is realized by master systems and a slave system. The motion saving system saves motion of a slave system when human operator moves the master systems. At the same time, identity ratio is introduced to decouple the masters motions. The identity ratio of each master system is calculated by force of all master systems, and are saved to memory. On the contrary, real-world master systems and a virtual-world slave system realize the motion loading system. The motion loading system reproduces the motion using saved motion data and value of the identity ratio. The paper confirms that the motion saving system and motion loading system based on multilateral controller is generalized. The reproduced position and force correspond to the saved ones by the proposed method.

  1. Fine-Motion-Control Method for Realizing High-Accuracy and High-Speed Contact Motion of Industrial Robots by Employing Sensorless Force Control

    NASA Astrophysics Data System (ADS)

    Shimada, Naoki; Yoshioka, Takashi; Ohishi, Kiyoshi; Miyazaki, Toshimasa

    This paper proposes a new fine-motion-control method for realizing high-accuracy and high-speed contact motion of industrial robots by employing sensorless force control. Today, although industrial robots have become considerably important in the modern industrial society, their functions are limited. A typical limited function is the positioning motion control of robots used in the manufacturing industry. Contact motion is necessary for almost all new applications. In this study, by employing the proposed motion control, smooth and quick contact motion of industrial robots is realized by using a sensorless I-P (Integral-Proportional) force feedback controller. The proposed method is simple and effective, takes into account both the inertia of a robot and the behavior of the I-P force controller. In the experiments, a three-degree-of-freedom robot is brought into contact with an object (a concrete block or a rubber board) by the I-P force control using the proposed method. Further, in the experiment, the motion of the robot's end-effector was considered. The validity of the proposed method is confirmed by using a six-axis force sensor and an acceleration sensor in the contact motion experiments.

  2. Modeling Human Control of Self-Motion Direction With Optic Flow and Vestibular Motion.

    PubMed

    Zaal, Peter M T; Nieuwenhuizen, Frank M; van Paassen, Marinus M; Mulder, Max

    2013-04-01

    In this paper, we investigate the effects of visual and motion stimuli on the manual control of one's direction of self-motion. In a flight simulator, subjects conducted an active target-following disturbance-rejection task, using a compensatory display. Simulating a vehicular control task, the direction of vehicular motion was shown on the outside visual display in two ways: an explicit presentation using a symbol and an implicit presentation, namely, through the focus of radial outflow that emerges from optic flow. In addition, the effects of the relative strength of congruent vestibular motion cues were investigated. The dynamic properties of human visual and vestibular motion perception paths were modeled using a control-theoretical approach. As expected, improved tracking performance was found for the configurations that explicitly showed the direction of self-motion. The human visual time delay increased with approximately 150 ms for the optic flow conditions, relative to explicit presentations. Vestibular motion, providing higher order information on the direction of self-motion, allowed subjects to partially compensate for this visual perception delay, improving performance. Parameter estimates of the operator control model show that, with vestibular motion, the visual feedback becomes stronger, indicating that operators are more confident to act on optic flow information when congruent vestibular motion cues are present.

  3. Tracking 3-D body motion for docking and robot control

    NASA Technical Reports Server (NTRS)

    Donath, M.; Sorensen, B.; Yang, G. B.; Starr, R.

    1987-01-01

    An advanced method of tracking three-dimensional motion of bodies has been developed. This system has the potential to dynamically characterize machine and other structural motion, even in the presence of structural flexibility, thus facilitating closed loop structural motion control. The system's operation is based on the concept that the intersection of three planes defines a point. Three rotating planes of laser light, fixed and moving photovoltaic diode targets, and a pipe-lined architecture of analog and digital electronics are used to locate multiple targets whose number is only limited by available computer memory. Data collection rates are a function of the laser scan rotation speed and are currently selectable up to 480 Hz. The tested performance on a preliminary prototype designed for 0.1 in accuracy (for tracking human motion) at a 480 Hz data rate includes a worst case resolution of 0.8 mm (0.03 inches), a repeatability of plus or minus 0.635 mm (plus or minus 0.025 inches), and an absolute accuracy of plus or minus 2.0 mm (plus or minus 0.08 inches) within an eight cubic meter volume with all results applicable at the 95 percent level of confidence along each coordinate region. The full six degrees of freedom of a body can be computed by attaching three or more target detectors to the body of interest.

  4. Visual-Motion Cueing in Altitude and Yaw Control

    NASA Technical Reports Server (NTRS)

    Johnson, Walter W.; Schroeder, Jeffery; Statler, Irving C. (Technical Monitor)

    1994-01-01

    Research conducted using the Vertical Motion Simulator at the NASA Ames Research Center examined the contributions of platform motion and visual level-of-detail (LOD) cueing to tasks that required altitude and/or yaw control in a simulated AH-64 Apache helicopter. Within the altitude control tasks the LOD manipulation caused optical density to change across altitudes by a small, moderate, or large amount; while platform motion was either present or absent. The results from these tasks showed that both constant optical density and platform motion improved altitude awareness in an altitude repositioning task, while the presence of platform motion also led to improved performance in a vertical rate control task. The yaw control tasks had pilots'sit 4.5 ft in front of the center of rotation, thus subjecting them to both rotational and lateral motions during a yaw. The pilots were required to regulate their yaw, while the platform motion was manipulated in order to present all combinations of the resulting rotational and lateral motion components. Ratings of simulation fidelity and sensed platform motion showed that the pilots were relatively insensitive to the rotational component, but highly aware of the lateral component. Together these findings show that: 1) platform motion cues are important when speed regulation is required during altitude change; 2) platform motion contributes to the perception of movement amplitude; 3) lateral, but not rotational, motion cues are essential to the perception of vehicle yaw; and 4) LOD management yielding constant optical density across altitudes improves altitude awareness.

  5. Motion sickness: Can it be controlled

    NASA Technical Reports Server (NTRS)

    Carnes, David

    1988-01-01

    NASA is one of the few research centers concerned with motion sickness. Since the physiology of man has been developed in the one-gravity field Earth, the changes experienced by man in space are unique, and often result in symptoms that resemble motion sickness on Earth. NASA is concerned with motion sickness because it is very uncomfortable for the astronauts. Another concern of NASA is the possibility of a motion sickness astronaut regurgitating while he or she is sealed in an airtight space suit. This could be fatal. Motivated by these reasons, NASA spent thousands of dollars in research and development for a drug or technique for combating motion sickness. Several different treatments were developed for this disorder. Three of the most effective ways of combatting motion sickness are discussed.

  6. Modular motion control produces cost-effective conveying

    SciTech Connect

    Yackel, R.A.

    1997-08-01

    Collectively, US power plants move as much as 800 million tons of coal a year through the mining, transport, off-loading, stockpiling and consumption sequence, most typically through the use of belt conveyors. Plant operators oversee a process that moves mountains of coal accurately and dependably, guarding against overloading, loss of conveyor-to-conveyor synchronization, belt slippage and other malfunctions. A coal-conveying motion-control system should consist of modular, turnkey motion-sensing components that can be assembled and interconnected for any application without custom engineering. Such a system can be fail-safe, provide uninterrupted protection, resist difficult environmental conditions, integrate complex multiple functions and allow power plant operators to take instant action to protect against damage in the event of a system fault.

  7. Immunoglobulin Structure Exhibits Control over CDR Motion

    PubMed Central

    Zimmermann, Michael T.; Skliros, Aris; Kloczkowski, Andrzej; Jernigan, Robert L.

    2014-01-01

    Motions of the IgG structure are evaluated using normal mode analysis of an elastic network model to detect hinges, the dominance of low frequency modes, and the most important internal motions. One question we seek to answer is whether or not IgG hinge motions facilitate antigen binding. We also evaluate the protein crystal and packing effects on the experimental temperature factors and disorder predictions. We find that the effects of the protein environment on the crystallographic temperature factors may be misleading for evaluating specific functional motions of IgG. The extent of motion of the antigen binding domains is computed to show their large spatial sampling. We conclude that the IgG structure is specifically designed to facilitate large excursions of the antigen binding domains. Normal modes are shown as capable of computationally evaluating the hinge motions and the spatial sampling by the structure. The antigen binding loops and the major hinge appear to behave similarly to the rest of the structure when we consider the dominance of the low frequency modes and the extent of internal motion. The full IgG structure has a lower spectral dimension than individual Fab domains, pointing to more efficient information transfer through the antibody than through each domain. This supports the claim that the IgG structure is specifically constructed to facilitate antigen binding by coupling motion of the antigen binding loops with the large scale hinge motions. PMID:25191522

  8. Control strategies for planetary rover motion and manipulator control

    NASA Technical Reports Server (NTRS)

    Trautwein, W.

    1973-01-01

    An unusual insect-like vehicle designed for planetary surface exploration is made the occasion for a discussion of control concepts in path selection, hazard detection, obstacle negotiation, and soil sampling. A control scheme which actively articulates the pitching motion between a single-loop front module and a dual loop rear module leads to near optimal behavior in soft soil; at the same time the vehicle's front module acts as a reliable tactile forward probe with a detection range much longer than the stopping distance. Some optimal control strategies are discussed, and the photos of a working scale model are displayed.

  9. Human Motion Energy Harvesting for AAL Applications

    NASA Astrophysics Data System (ADS)

    Ylli, K.; Hoffmann, D.; Becker, P.; Willmann, A.; Folkmer, B.; Manoli, Y.

    2014-11-01

    Research and development into the topic of ambient assisted living has led to an increasing range of devices that facilitate a person's life. The issue of the power supply of these modern mobile systems however has not been solved satisfactorily yet. In this paper a flat inductive multi-coil harvester for integration into the shoe sole is presented. The device is designed for ambient assisted living (AAL) applications and particularly to power a self-lacing shoe. The harvester exploits the horizontal swing motion of the foot to generate energy. Stacks of opposing magnets move through a number of equally spaced coils to induce a voltage. The requirement of a flat structure which can be integrated into the shoe sole is met by a reduced form factor of the magnet stack. In order to exploit the full width of the shoe sole, supporting structures are used to parallelize the harvester and therefore increase the number of active elements, i.e. magnets and coils. The development and characterization of different harvester variations is presented with the best tested design generating an average power of up to 2.14 mW at a compact device size of 75 × 41.5 × 15 mm3 including housing.

  10. Proposal of Method for Control of Muscle Activation Level for Limbs during Motion and Application of this Method in Strength Training

    NASA Astrophysics Data System (ADS)

    Komada, Satoshi; Murakami, Yosuke; Hirai, Junji

    With an increase in the number of elderly people in our society, the need for equipments that ensure activities of daily living and that can be used in strength training for reducing the need for nursing care is increasing. In this paper, we propose a method for controlling the level of muscle activation for a particular muscle group without EMG sensors; the force exerted by the tips of the limbs during motion is used to control the level of muscle activation. The method is based on a musculoskeletal model for limbs called functionally different effective muscles of three antagonistic pairs of six muscles in 2D space. Hill's equation is incorporated in the method to consider force-velocity characteristics of muscles. EMG measurement results for two muscles under isokinetic contraction in the lower limbs of a subject show that difference between the achieved activation level and the desired activation level is less than the error of the output force distribution. Moreover, the control method is applied to strength training. A manipulator that can facilitate the isokinetic contraction with more than the desired activation level for a specific muscle group is developed.

  11. Characterization and control of self-motions in redundant manipulators

    NASA Technical Reports Server (NTRS)

    Burdick, J.; Seraji, Homayoun

    1989-01-01

    The presence of redundant degrees of freedom in a manipulator structure leads to a physical phenomenon known as a self-motion, which is a continuous motion of the manipulator joints that leaves the end-effector motionless. In the first part of the paper, a global manifold mapping reformulation of manipulator kinematics is reviewed, and the inverse kinematic solution for redundant manipulators is developed in terms of self-motion manifolds. Global characterizations of the self-motion manifolds in terms of their number, geometry, homotopy class, and null space are reviewed using examples. Much previous work in redundant manipulator control has been concerned with the redundancy resolution problem, in which methods are developed to determine, or resolve, the motion of the joints in order to achieve end-effector trajectory control while optimizing additional objective functions. Redundancy resolution problems can be equivalently posed as the control of self-motions. Alternatives for redundancy resolution are briefly discussed.

  12. Controlling the motion of a group of mobile agents

    NASA Astrophysics Data System (ADS)

    Levin, V. A.; Osipov, G. V.

    2016-03-01

    We propose a method of controlling an ensemble of mobile agents with variable coupling topology that is based on the principles of phase synchronization in a system of regular and chaotic oscillators. Results of modeling of the controlled motion of mobile agents in systems with serial, parallel, and strictly preset motion are presented.

  13. Multi-application controls: Robust nonlinear multivariable aerospace controls applications

    NASA Technical Reports Server (NTRS)

    Enns, Dale F.; Bugajski, Daniel J.; Carter, John; Antoniewicz, Bob

    1994-01-01

    This viewgraph presentation describes the general methodology used to apply Honywell's Multi-Application Control (MACH) and the specific application to the F-18 High Angle-of-Attack Research Vehicle (HARV) including piloted simulation handling qualities evaluation. The general steps include insertion of modeling data for geometry and mass properties, aerodynamics, propulsion data and assumptions, requirements and specifications, e.g. definition of control variables, handling qualities, stability margins and statements for bandwidth, control power, priorities, position and rate limits. The specific steps include choice of independent variables for least squares fits to aerodynamic and propulsion data, modifications to the management of the controls with regard to integrator windup and actuation limiting and priorities, e.g. pitch priority over roll, and command limiting to prevent departures and/or undesirable inertial coupling or inability to recover to a stable trim condition. The HARV control problem is characterized by significant nonlinearities and multivariable interactions in the low speed, high angle-of-attack, high angular rate flight regime. Systematic approaches to the control of vehicle motions modeled with coupled nonlinear equations of motion have been developed. This paper will discuss the dynamic inversion approach which explicity accounts for nonlinearities in the control design. Multiple control effectors (including aerodynamic control surfaces and thrust vectoring control) and sensors are used to control the motions of the vehicles in several degrees-of-freedom. Several maneuvers will be used to illustrate performance of MACH in the high angle-of-attack flight regime. Analytical methods for assessing the robust performance of the multivariable control system in the presence of math modeling uncertainty, disturbances, and commands have reached a high level of maturity. The structured singular value (mu) frequency response methodology is presented

  14. Control Design for a Motion Cueing on Driving Simulator

    NASA Astrophysics Data System (ADS)

    de-J. Lozoya-Santos, Jorge; Tudon-Martinez, Juan C.; Salinas, Julio

    2017-01-01

    A Linear Quadratic Regulator (LQR) has been designed to simulate the pitch and roll vehicle dynamics of a platform which is connected to the real time simulation environment of Dynacar. The motion cueing algorithm translates the movement of the simulated vehicle to the platform using three rotary actuators, by satisfying all actuation boundaries. Experimental results illustrate that the LQR motion cueing algorithm performs satisfactory the tracking control at low frequencies, close to the resonance frequencies of the pitch and roll motion.

  15. LabVIEW application for motion tracking using USB camera

    NASA Astrophysics Data System (ADS)

    Rob, R.; Tirian, G. O.; Panoiu, M.

    2017-05-01

    The technical state of the contact line and also the additional equipment in electric rail transport is very important for realizing the repairing and maintenance of the contact line. During its functioning, the pantograph motion must stay in standard limits. Present paper proposes a LabVIEW application which is able to track in real time the motion of a laboratory pantograph and also to acquire the tracking images. An USB webcam connected to a computer acquires the desired images. The laboratory pantograph contains an automatic system which simulates the real motion. The tracking parameters are the horizontally motion (zigzag) and the vertically motion which can be studied in separate diagrams. The LabVIEW application requires appropriate tool-kits for vision development. Therefore the paper describes the subroutines that are especially programmed for real-time image acquisition and also for data processing.

  16. Orientation Control Method and System for Object in Motion

    NASA Technical Reports Server (NTRS)

    Whorton, Mark Stephen (Inventor); Redmon, Jr., John W. (Inventor); Cox, Mark D. (Inventor)

    2012-01-01

    An object in motion has a force applied thereto at a point of application. By moving the point of application such that the distance between the object's center-of-mass and the point of application is changed, the object's orientation can be changed/adjusted.

  17. Current-controlled unidirectional edge-meron motion

    NASA Astrophysics Data System (ADS)

    Xing, Xiangjun; Pong, Philip W. T.; Zhou, Yan

    2016-11-01

    In order to address many of the challenges and bottlenecks currently experienced by traditional charge-based technologies, various alternatives are being actively explored to provide potential solutions of device miniaturization and scaling in the post-Moore's-law era. Amongst these alternatives, spintronic physics and devices have recently attracted rapidly increasing interest by exploiting the additional degree of electrons-spin. For example, magnetic domain-wall racetrack-memory and logic devices have been realized via manipulating domain-wall motion. As compared to domain-wall-based devices, magnetic skyrmions have the advantages of ultrasmall size (typically 5-100 nm in diameter), facile current-driven motion, topological stability, and peculiar emergent electrodynamics, promising for next-generation electronics applications in the post-Moore's-law regime. Here, a magnetic meron device, which behaves similarly to a PN-junction diode, is demonstrated for the first time, by tailoring the current-controlled unidirectional motion of edge-merons (i.e., fractional skyrmions) in a nanotrack with interfacial Dzyaloshinskii-Moriya interaction. The working principles of the meron device, theoretically predicted from the Thiele equation for topological magnetic objects, are further verified using micromagnetic simulations. The present study has revealed the topology-independent transport property of different magnetic objects and is expected to open the vista toward integrated composite circuitry (with unified data storage and processing) based on a single magnetic chip, as the meron device can be used, either as a building block to develop complex logic components or as a signal controller to interconnect skyrmion, domain-wall, and even spin-wave devices.

  18. Calculation of the transient motion of elastic airfoils forced by control surface motion and gusts

    NASA Technical Reports Server (NTRS)

    Balakrishnan, A. V.; Edwards, J. W.

    1980-01-01

    The time-domain equations of motion of elastic airfoil sections forced by control surface motions and gusts were developed for the case of incompressible flow. Extensive use was made of special functions related to the inverse transform of Theodorsen's function. Approximations for the special cases of zero stream velocity, small time, large and time are given. A numerical solution technique for the solution of the general case is given. Examples of the exact transient response of an airfoil are presented.

  19. Toolkits Control Motion of Complex Robotics

    NASA Technical Reports Server (NTRS)

    2010-01-01

    That space is a hazardous environment for humans is common knowledge. Even beyond the obvious lack of air and gravity, the extreme temperatures and exposure to radiation make the human exploration of space a complicated and risky endeavor. The conditions of space and the space suits required to conduct extravehicular activities add layers of difficulty and danger even to tasks that would be simple on Earth (tightening a bolt, for example). For these reasons, the ability to scout distant celestial bodies and perform maintenance and construction in space without direct human involvement offers significant appeal. NASA has repeatedly turned to complex robotics for solutions to extend human presence deep into space at reduced risk and cost and to enhance space operations in low Earth orbit. At Johnson Space Center, engineers explore the potential applications of dexterous robots capable of performing tasks like those of an astronaut during extravehicular activities and even additional ones too delicate or dangerous for human participation. Johnson's Dexterous Robotics Laboratory experiments with a wide spectrum of robot manipulators, such as the Mitsubishi PA-10 and the Robotics Research K-1207i robotic arms. To simplify and enhance the use of these robotic systems, Johnson researchers sought generic control methods that could work effectively across every system.

  20. Electric Wheelchair Controlled by Human Body Motion Interface

    NASA Astrophysics Data System (ADS)

    Yokota, Sho; Hashimoto, Hiroshi; Ohyama, Yasuhiro; She, Jin-Hua

    This research studies the possibility of an intuitive interface for an electric wheelchair by using human body except hands. For this purpose, we focused on the human body motion which has relation to actions or behavior. This motion comes from the human stabilization function for holding expectable collapsing caused by voluntary motion. Thus this motion is considered as a kind of characteristics of human motion, and is linked to intentions unconsciously. Therefore, the interface which does not require conscious and complex motion is realized by applying this human body motion to the interface of electric wheelchair. In this paper, first, we did experiment to search a part which vividly shows the pressure change on the seat. As a result, it was confirmed that pressure change of the seat back vividly shows the human body motion. Next, we designed the prototype based on this evidence. Finally, experiment was conducted by using 10 subjects and SD method to evaluate feeling of operation. For this result, it was turned out that all subjects feel that proposed interface was intuitive, or to control at their direction. Therefore it was confirmed that human body motion interface has a possibility to be used for an interface of electric wheelchair.

  1. Human joint motion estimation for electromyography (EMG)-based dynamic motion control.

    PubMed

    Zhang, Qin; Hosoda, Ryo; Venture, Gentiane

    2013-01-01

    This study aims to investigate a joint motion estimation method from Electromyography (EMG) signals during dynamic movement. In most EMG-based humanoid or prosthetics control systems, EMG features were directly or indirectly used to trigger intended motions. However, both physiological and nonphysiological factors can influence EMG characteristics during dynamic movements, resulting in subject-specific, non-stationary and crosstalk problems. Particularly, when motion velocity and/or joint torque are not constrained, joint motion estimation from EMG signals are more challenging. In this paper, we propose a joint motion estimation method based on muscle activation recorded from a pair of agonist and antagonist muscles of the joint. A linear state-space model with multi input single output is proposed to map the muscle activity to joint motion. An adaptive estimation method is proposed to train the model. The estimation performance is evaluated in performing a single elbow flexion-extension movement in two subjects. All the results in two subjects at two load levels indicate the feasibility and suitability of the proposed method in joint motion estimation. The estimation root-mean-square error is within 8.3% ∼ 10.6%, which is lower than that being reported in several previous studies. Moreover, this method is able to overcome subject-specific problem and compensate non-stationary EMG properties.

  2. Motion and force control for multiple cooperative manipulators

    NASA Technical Reports Server (NTRS)

    Wen, John T.; Kreutz, Kenneth

    1989-01-01

    The motion and force control of multiple robot arms manipulating a commonly held object is addressed. A general control paradigm that decouples the motion and force control problems is introduced. For motion control, there are three natural choices: (1) joint torques, (2) arm-tip force vectors, and (3) the acceleration of a generalized coordinate. Choice (1) allows a class of relatively model-independent control laws by exploiting the Hamiltonian structure of the open-loop system; (2) and (3) require the full model information but produce simpler problems. To resolve the nonuniqueness of the joint torques, two methods are introduced. If the arm and object models are available, the allocation of the desired end-effector control force to the joint actuators can be optimized; otherwise the internal force can be controlled about some set point. It is shown that effective force regulation can be achieved even if little model information is available.

  3. Motion and force control for multiple cooperative manipulators

    NASA Technical Reports Server (NTRS)

    Wen, John T.; Kreutz, Kenneth

    1989-01-01

    The motion and force control of multiple robot arms manipulating a commonly held object is addressed. A general control paradigm that decouples the motion and force control problems is introduced. For motion control, there are three natural choices: (1) joint torques, (2) arm-tip force vectors, and (3) the acceleration of a generalized coordinate. Choice (1) allows a class of relatively model-independent control laws by exploiting the Hamiltonian structure of the open-loop system; (2) and (3) require the full model information but produce simpler problems. To resolve the nonuniqueness of the joint torques, two methods are introduced. If the arm and object models are available, the allocation of the desired end-effector control force to the joint actuators can be optimized; otherwise the internal force can be controlled about some set point. It is shown that effective force regulation can be achieved even if little model information is available.

  4. Dual-Arm Generalized Compliant Motion With Shared Control

    NASA Technical Reports Server (NTRS)

    Backes, Paul G.

    1994-01-01

    Dual-Arm Generalized Compliant Motion (DAGCM) primitive computer program implementing improved unified control scheme for two manipulator arms cooperating in task in which both grasp same object. Provides capabilities for autonomous, teleoperation, and shared control of two robot arms. Unifies cooperative dual-arm control with multi-sensor-based task control and makes complete task-control capability available to higher-level task-planning computer system via large set of input parameters used to describe desired force and position trajectories followed by manipulator arms. Some concepts discussed in "A Generalized-Compliant-Motion Primitive" (NPO-18134).

  5. Standing and sitting motion of inverted pendulum type assist robot using whole-body motion with force control

    NASA Astrophysics Data System (ADS)

    Jeong, SeongHee; Takahashi, Takayuki

    2007-12-01

    This paper describes quick and stable standing and sitting motion of an inverted pendulum type robot by wholebody motion including force control. The whole-body motion is achieved by controlling composite center of gravity of the robot, and damping force control of a wrist-roller is employed to assure the stability of inverted pendulum control on a contact situation with the ground. Motion planning of standing and sitting based on the proposed control method is also proposed. Standing and sitting motion using the proposed motion control and motion planning is simulated with a dynamic simulator, ODE(Open Dynamics Engine). From the simulation results, it was confirmed that the robot successively realized the standing and sitting motion quickly and stably.

  6. The influence of ship motion of manual control skills

    NASA Technical Reports Server (NTRS)

    Mcleod, P.; Poulton, C.; Duross, H.; Lewis, W.

    1981-01-01

    The effects of ship motion on a range of typical manual control skills were examined on the Warren Spring ship motion simulator driven in heave, pitch, and roll by signals taken from the frigate HMS Avenger at 13 m/s (25 knots) into a force 4 wind. The motion produced a vertical r.m.s. acceleration of 0.024g, mostly between 0.1 and 0.3 Hz, with comparatively little pitch or roll. A task involving unsupported arm movements was seriously affected by the motion; a pursuit tracking task showed a reliable decrement although it was still performed reasonably well (pressure and free moving tracking controls were affected equally by the motion); a digit keying task requiring ballistic hand movements was unaffected. There was no evidence that these effects were caused by sea sickness. The differing response to motion of the different tasks, from virtual destruction to no effect, suggests that a major benefit could come from an attempt to design the man/control interface onboard ship around motion resistant tasks.

  7. Motion and force control of multiple robotic manipulators

    NASA Technical Reports Server (NTRS)

    Wen, John T.; Kreutz-Delgado, Kenneth

    1992-01-01

    This paper addresses the motion and force control problem of multiple robot arms manipulating a cooperatively held object. A general control paradigm is introduced which decouples the motion and force control problems. For motion control, different control strategies are constructed based on the variables used as the control input in the controller design. There are three natural choices; acceleration of a generalized coordinate, arm tip force vectors, and the joint torques. The first two choices require full model information but produce simple models for the control design problem. The last choice results in a class of relatively model independent control laws by exploiting the Hamiltonian structure of the open loop system. The motion control only determines the joint torque to within a manifold, due to the multiple-arm kinematic constraint. To resolve the nonuniqueness of the joint torques, two methods are introduced. If the arm and object models are available, an optimization can be performed to best allocate the desired and effector control force to the joint actuators. The other possibility is to control the internal force about some set point. It is shown that effective force regulation can be achieved even if little model information is available.

  8. Motion and force control of multiple robotic manipulators

    NASA Technical Reports Server (NTRS)

    Wen, John T.; Kreutz-Delgado, Kenneth

    1992-01-01

    This paper addresses the motion and force control problem of multiple robot arms manipulating a cooperatively held object. A general control paradigm is introduced which decouples the motion and force control problems. For motion control, different control strategies are constructed based on the variables used as the control input in the controller design. There are three natural choices; acceleration of a generalized coordinate, arm tip force vectors, and the joint torques. The first two choices require full model information but produce simple models for the control design problem. The last choice results in a class of relatively model independent control laws by exploiting the Hamiltonian structure of the open loop system. The motion control only determines the joint torque to within a manifold, due to the multiple-arm kinematic constraint. To resolve the nonuniqueness of the joint torques, two methods are introduced. If the arm and object models are available, an optimization can be performed to best allocate the desired and effector control force to the joint actuators. The other possibility is to control the internal force about some set point. It is shown that effective force regulation can be achieved even if little model information is available.

  9. Stochastic boundary control design for Timoshenko beams with large motions

    NASA Astrophysics Data System (ADS)

    Do, K. D.

    2017-08-01

    This paper considers modeling and boundary control of Timoshenko beams with large motions under both deterministic and stochastic external loads. The original nonlinear partial differential equations governing motion of the beams are derived and used in the control design. The control design is based on the Lyapunov direct method. The proposed controllers guarantee globally practically K∞-exponentially p-stability of the beam motions at the reference state. Well-posedness and stability are analyzed based on a Lyapunov-type theorem developed to study well-posedness and stability for a class of stochastic evolution systems in Hilbert space. Simulation results are included to illustrate the effectiveness of the proposed control design.

  10. Motion cue effects on human pilot dynamics in manual control

    NASA Technical Reports Server (NTRS)

    Washizu, K.; Tanaka, K.; Endo, S.; Itoko, T.

    1977-01-01

    Two experiments were conducted to study the motion cue effects on human pilots during tracking tasks. The moving-base simulator of National Aerospace Laboratory was employed as the motion cue device, and the attitude director indicator or the projected visual field was employed as the visual cue device. The chosen controlled elements were second-order unstable systems. It was confirmed that with the aid of motion cues the pilot workload was lessened and consequently the human controllability limits were enlarged. In order to clarify the mechanism of these effects, the describing functions of the human pilots were identified by making use of the spectral and the time domain analyses. The results of these analyses suggest that the sensory system of the motion cues can yield the differential informations of the signal effectively, which coincides with the existing knowledges in the physiological area.

  11. The Digital Motion Control System for the Submillimeter Array Antennas

    NASA Astrophysics Data System (ADS)

    Hunter, T. R.; Wilson, R. W.; Kimberk, R.; Leiker, P. S.; Patel, N. A.; Blundell, R.; Christensen, R. D.; Diven, A. R.; Maute, J.; Plante, R. J.; Riddle, P.; Young, K. H.

    2013-09-01

    We describe the design and performance of the digital servo and motion control system for the 6-meter parabolic antennas of the Submillimeter Array (SMA) on Mauna Kea, Hawaii. The system is divided into three nested layers operating at a different, appropriate bandwidth. (1) A rack-mounted, real-time Unix system runs the position loop which reads the high resolution azimuth and elevation encoders and sends velocity and acceleration commands at 100 Hz to a custom-designed servo control board (SCB). (2) The microcontroller-based SCB reads the motor axis tachometers and implements the velocity loop by sending torque commands to the motor amplifiers at 558 Hz. (3) The motor amplifiers implement the torque loop by monitoring and sending current to the three-phase brushless drive motors at 20 kHz. The velocity loop uses a traditional proportional-integral-derivative (PID) control algorithm, while the position loop uses only a proportional term and implements a command shaper based on the Gauss error function. Calibration factors and software filters are applied to the tachometer feedback prior to the application of the servo gains in the torque computations. All of these parameters are remotely adjustable in the software. The three layers of the control system monitor each other and are capable of shutting down the system safely if a failure or anomaly occurs. The Unix system continuously relays the antenna status to the central observatory computer via reflective memory. In each antenna, a Palm Vx hand controller displays the complete system status and allows full local control of the drives in an intuitive touchscreen user interface. The hand controller can also be connected outside the cabin, a major convenience during the frequent reconfigurations of the interferometer. Excellent tracking performance ( 0.3‧‧ rms) is achieved with this system. It has been in reliable operation on 8 antennas for over 10 years and has required minimal maintenance.

  12. Sensing human hand motions for controlling dexterous robots

    NASA Technical Reports Server (NTRS)

    Marcus, Beth A.; Churchill, Philip J.; Little, Arthur D.

    1988-01-01

    The Dexterous Hand Master (DHM) system is designed to control dexterous robot hands such as the UTAH/MIT and Stanford/JPL hands. It is the first commercially available device which makes it possible to accurately and confortably track the complex motion of the human finger joints. The DHM is adaptable to a wide variety of human hand sizes and shapes, throughout their full range of motion.

  13. Spatial design and control of graphene flake motion

    NASA Astrophysics Data System (ADS)

    Ghorbanfekr-Kalashami, H.; Peeters, F. M.; Novoselov, K. S.; Neek-Amal, M.

    2017-08-01

    The force between a sharp scanning probe tip and a surface can drive a graphene flake over crystalline substrates. The recent design of particular patterns of structural defects on a graphene surface allows us to propose an alternative approach for controlling the motion of a graphene flake over a graphene substrate. The thermally induced motion of a graphene flake is controlled by engineering topological defects in the substrate. Such defect regions lead to an inhomogeneous energy landscape and are energetically unfavorable for the motion of the flake, and will invert and scatter graphene flakes when they are moving toward the defect line. Engineering the distribution of these energy barriers results in a controllable trajectory for the thermal motion of the flake without using any external force. We predict superlubricity of the graphene flake for motion along and between particular defect lines. This Rapid Communication provides insights into the frictional forces of interfaces and opens a route to the engineering of the stochastic motion of a graphene flake over any crystalline substrate.

  14. Real-time simulation of hand motion for prosthesis control.

    PubMed

    Blana, Dimitra; Chadwick, Edward K; van den Bogert, Antonie J; Murray, Wendy M

    2017-04-01

    Individuals with hand amputation suffer substantial loss of independence. Performance of sophisticated prostheses is limited by the ability to control them. To achieve natural and simultaneous control of all wrist and hand motions, we propose to use real-time biomechanical simulation to map between residual EMG and motions of the intact hand. Here we describe a musculoskeletal model of the hand using only extrinsic muscles to determine whether real-time performance is possible. Simulation is 1.3 times faster than real time, but the model is locally unstable. Methods are discussed to increase stability and make this approach suitable for prosthesis control.

  15. Study of Neuro-Controllers for Motion Control Systems with Distributed Mechanical Flexibility.

    DTIC Science & Technology

    2007-11-02

    Control of motion systems involving distributed mechanical flexibility is studied using artificial neural networks . Infinite dimensional nature of...into consideration. Three different neuro controller architectures are studied: 1) Hopfield nets for modal parameter estimation and real time solution of...neural network controller for high precision motion control. Thre results are summarized and details are presented in refereed publications.

  16. Motion Imagery and Robotics Application (MIRA)

    NASA Technical Reports Server (NTRS)

    Martinez, Lindolfo; Rich, Thomas

    2011-01-01

    Objectives include: I. Prototype a camera service leveraging the CCSDS Integrated protocol stack (MIRA/SM&C/AMS/DTN): a) CCSDS MIRA Service (New). b) Spacecraft Monitor and Control (SM&C). c) Asynchronous Messaging Service (AMS). d) Delay/Disruption Tolerant Networking (DTN). II. Additional MIRA Objectives: a) Demo of Camera Control through ISS using CCSDS protocol stack (Berlin, May 2011). b) Verify that the CCSDS standards stack can provide end-to-end space camera services across ground and space environments. c) Test interoperability of various CCSDS protocol standards. d) Identify overlaps in the design and implementations of the CCSDS protocol standards. e) Identify software incompatibilities in the CCSDS stack interfaces. f) Provide redlines to the SM&C, AMS, and DTN working groups. d) Enable the CCSDS MIRA service for potential use in ISS Kibo camera commanding. e) Assist in long-term evolution of this entire group of CCSDS standards to TRL 6 or greater.

  17. Robotic Implementation of Realistic Reaching Motion Using a Sliding Mode/Operational Space Controller

    NASA Astrophysics Data System (ADS)

    Spiers, Adam; Herrmann, Guido; Melhuish, Chris; Pipe, Tony; Lenz, Alexander

    It has been shown that a task-level controller with minimal-effort posture control produces human-like motion in simulation. This control approach is based on the dynamic model of a human skeletal system superimposed with realistic muscle like actuators whose effort is minimised. In practical application, there is often a degree of error between the dynamic model of a system used for controller derivation and the actual dynamics of the system. We present a practical application of the task-level control framework with simplified posture control in order to produce life-like and compliant reaching motions for a redundant task. The addition of a sliding mode controller improves performance of the physical robot by compensating for unknown parametric and dynamic disturbances without compromising the human-like posture.

  18. Singularly Weighted Symplectic Forms and Applications to Asteroid Motion

    NASA Astrophysics Data System (ADS)

    Varadi, F.; de La Barre, C. M.; Kaula, W. M.; Ghil, M.

    1995-05-01

    New techniques to study Hamiltonian systems with Hamiltonian forcing are proposed. They are based on singularly weighted symplectic forms and transformations which preserve these forms. Applications pertaining to asteroid motion are outlined. These involve the presence of both Jupiter and Saturn.

  19. Motion synchronization in unmanned aircrafts formation control with communication delays

    NASA Astrophysics Data System (ADS)

    Rezaee, Hamed; Abdollahi, Farzaneh

    2013-03-01

    This paper proposes a formation control strategy for unmanned aircrafts using a virtual structure. Cross coupled sliding mode controllers are introduced to cope with uncertainties in the attitude measurement systems of the unmanned aircrafts and unmeasurable bounded external disturbances such as wind effects, and also to provide motion synchronization in the multi-agent system. This motion synchronization strategy improves the agents convergence to their desired positions, and this is useful for a multi-agent system with faulty agents. Moreover, the proposed motion synchronization strategy is not restricted to specific communication topologies, and sufficient conditions are provided to guarantee the multi-agent system stability in the presence of communication delays. Numerical simulations are presented for a team of five unmanned aircrafts to make a pentagon formation and confirm the accepted performance of the proposed control strategy.

  20. Singularity-consistent parameterization of robot motion and control

    SciTech Connect

    Nenchev, D.N.; Tsumaki, Yuichi; Uchiyama, Masaru

    2000-02-01

    The inverse kinematics problem is formulated as a parameterized autonomous dynamical system problem, and respective analysis is carried out. It is shown that a singular point of work space can be mapped either as a critical or a noncritical point of the autonomous system, depending on the direction of approach to the singular point. Making use of the noncritical mapping, a closed-loop kinematic controller with asymptotic stability and velocity limits along degenerate singular or near-singular paths is designed. The authors introduce a specific type of motion along the reference path, the so-called natural motion. This type of motion is obtained in a straightforward manner from the autonomous dynamical system and always satisfies the motion constraint at a singular point. In the vicinity of the singular point, natural motion slows down the end-effector speed and keeps the joint velocity bounded. Thus, no special trajectory replanning will be required. In addition, the singular manifold can be crossed, if necessary. Further on, it is shown that natural motion constitutes an integrable motion component. The remaining, nonintegrable motion component is shown to be helpful in solving a problem related to the critical point mapping of the autonomous system. The authors design a singularity-consistent resolved acceleration controller, which they then apply to singular or near-singular trajectory tracking under torque limits. Finally, the authors compare the main features of the singularity-consistent method and the damped-least-squares method. It is shown that both methods introduce a so-called algorithmic error in the vicinity of a singular point. The direction of this error is, however, different in each method. This is shown to play an important role for system stability.

  1. New human-centered linear and nonlinear motion cueing algorithms for control of simulator motion systems

    NASA Astrophysics Data System (ADS)

    Telban, Robert J.

    While the performance of flight simulator motion system hardware has advanced substantially, the development of the motion cueing algorithm, the software that transforms simulated aircraft dynamics into realizable motion commands, has not kept pace. To address this, new human-centered motion cueing algorithms were developed. A revised "optimal algorithm" uses time-invariant filters developed by optimal control, incorporating human vestibular system models. The "nonlinear algorithm" is a novel approach that is also formulated by optimal control, but can also be updated in real time. It incorporates a new integrated visual-vestibular perception model that includes both visual and vestibular sensation and the interaction between the stimuli. A time-varying control law requires the matrix Riccati equation to be solved in real time by a neurocomputing approach. Preliminary pilot testing resulted in the optimal algorithm incorporating a new otolith model, producing improved motion cues. The nonlinear algorithm vertical mode produced a motion cue with a time-varying washout, sustaining small cues for longer durations and washing out large cues more quickly compared to the optimal algorithm. The inclusion of the integrated perception model improved the responses to longitudinal and lateral cues. False cues observed with the NASA adaptive algorithm were absent. As a result of unsatisfactory sensation, an augmented turbulence cue was added to the vertical mode for both the optimal and nonlinear algorithms. The relative effectiveness of the algorithms, in simulating aircraft maneuvers, was assessed with an eleven-subject piloted performance test conducted on the NASA Langley Visual Motion Simulator (VMS). Two methods, the quasi-objective NASA Task Load Index (TLX), and power spectral density analysis of pilot control, were used to assess pilot workload. TLX analysis reveals, in most cases, less workload and variation among pilots with the nonlinear algorithm. Control input

  2. Enhancement of vortex induced forces and motion through surface roughness control

    DOEpatents

    Bernitsas, Michael M [Saline, MI; Raghavan, Kamaldev [Houston, TX

    2011-11-01

    Roughness is added to the surface of a bluff body in a relative motion with respect to a fluid. The amount, size, and distribution of roughness on the body surface is controlled passively or actively to modify the flow around the body and subsequently the Vortex Induced Forces and Motion (VIFM). The added roughness, when designed and implemented appropriately, affects in a predetermined way the boundary layer, the separation of the boundary layer, the level of turbulence, the wake, the drag and lift forces, and consequently the Vortex Induced Motion (VIM), and the fluid-structure interaction. The goal of surface roughness control is to increase Vortex Induced Forces and Motion. Enhancement is needed in such applications as harnessing of clean and renewable energy from ocean/river currents using the ocean energy converter VIVACE (Vortex Induced Vibration for Aquatic Clean Energy).

  3. Visual Features Involving Motion Seen from Airport Control Towers

    NASA Technical Reports Server (NTRS)

    Ellis, Stephen R.; Liston, Dorion

    2010-01-01

    Visual motion cues are used by tower controllers to support both visual and anticipated separation. Some of these cues are tabulated as part of the overall set of visual features used in towers to separate aircraft. An initial analyses of one motion cue, landing deceleration, is provided as a basis for evaluating how controllers detect and use it for spacing aircraft on or near the surface. Understanding cues like it will help determine if they can be safely used in a remote/virtual tower in which their presentation may be visually degraded.

  4. Robust, Flexible Motion Control for the Mars Explorer Rovers

    NASA Technical Reports Server (NTRS)

    Maimone, Mark; Biesiadecki, Jeffrey

    2007-01-01

    The Mobility Flight Software, running on computers aboard the Mars Explorer Rover (MER) robotic vehicles Spirit and Opportunity, affords the robustness and flexibility of control to enable safe and effective operation of these vehicles in traversing natural terrain. It can make the vehicles perform specific maneuvers commanded from Earth, and/or can autonomously administer multiple aspects of mobility, including choice of motion, measurement of actual motion, and even selection of targets to be approached. Motion of a vehicle can be commanded by use of multiple layers of control, ranging from motor control at a low level, direct drive operations (e.g., motion along a circular arc, motion along a straight line, or turn in place) at an intermediate level to goal-position driving (that is, driving to a specified location) at a high level. The software can also perform high-level assessment of terrain and selection of safe paths across the terrain: this involves processing of the digital equivalent of a local traversability map generated from images acquired by stereoscopic pairs of cameras aboard the vehicles. Other functions of the software include interacting with the rest of the MER flight software and performing safety checks.

  5. Do common systems control eye movements and motion extrapolation?

    PubMed

    Makin, Alexis D J; Poliakoff, Ellen

    2011-07-01

    People are able to judge the current position of occluded moving objects. This operation is known as motion extrapolation. It has previously been suggested that motion extrapolation is independent of the oculomotor system. Here we revisited this question by measuring eye position while participants completed two types of motion extrapolation task. In one task, a moving visual target travelled rightwards, disappeared, then reappeared further along its trajectory. Participants discriminated correct reappearance times from incorrect (too early or too late) with a two-alternative forced-choice button press. In the second task, the target travelled rightwards behind a visible, rectangular occluder, and participants pressed a button at the time when they judged it should reappear. In both tasks, performance was significantly different under fixation as compared to free eye movement conditions. When eye movements were permitted, eye movements during occlusion were related to participants' judgements. Finally, even when participants were required to fixate, small changes in eye position around fixation (<2°) were influenced by occluded target motion. These results all indicate that overlapping systems control eye movements and judgements on motion extrapolation tasks. This has implications for understanding the mechanism underlying motion extrapolation.

  6. Smart Rehabilitation Devices: Part II - Adaptive Motion Control.

    PubMed

    Dong, Shufang; Lu, Ke-Qian; Sun, J Q; Rudolph, Katherine

    2006-01-01

    This article presents a study of adaptive motion control of smart versatile rehabilitation devices using MR fluids. The device provides both isometric and isokinetic strength training and is reconfigurable for several human joints. Adaptive controls are developed to regulate resistance force based on the prescription of the therapist. Special consideration has been given to the human-machine interaction in the adaptive control that can modify the behavior of the device to account for strength gains or muscle fatigue of the human subject.

  7. Large motion tracking control for thrust magnetic bearings with fuzzy logic, sliding mode, and direct linearization

    NASA Astrophysics Data System (ADS)

    Minihan, T. P.; Lei, S.; Sun, G.; Palazzolo, A.; Kascak, A. F.; Calvert, T.

    2003-06-01

    Conventional use of magnetic bearings relies on a zero reference to keep the rotor centered in the radial and axial axes. This paper compares different control methods developed for the alternate control task of tracking an axial dynamic target. Controllers based on fuzzy logic, sliding mode, and direct linearization were designed to meet this task. Performance criteria, such as maximum axial displacement, minimum phase lag and I2R power losses were compared for each controller. The large motion, tracking problem for a rotor has utility in applications where dynamic seal clearances are required. This has a variety of potential applications in turbo-machinery, such as active stall control.

  8. Motion control of the accumulator flying wires

    SciTech Connect

    Wang, X.Q.

    1990-04-23

    Flying wire systems for the Fermilab Accumulator are being constructed in order to measure the transverse beam profiles during stacking. Each device passes a 25 micron carbon filament through the beam transversely at a constant velocity of 10 m/s. Collisions between the beam particles and the wire produce secondary particle cascades, which in turn produce photons in a scintillator. A photomultiplier tube is used to measure the light intensity while the wire position is determined by an optical encoder. There are six Accumulator flying wire systems. Four of them are to be used in normal stacking operation: two horizontal and two vertical flying wires are in the AP40 high dispersion section, covering the core orbit and the extraction orbit respectively. The other two horizontal wires are for measuring the momentum distribution of the beam on the central orbit at the Accumulator transition energy. At the AP40 high dispersion region a wire covers the central orbit, the other is in the AP30 low dispersion section. The operation and control of the flying wire system is discussed in this paper. 11 figs.

  9. Controlling the motion of multiple objects on a Chladni plate

    PubMed Central

    Zhou, Quan; Sariola, Veikko; Latifi, Kourosh; Liimatainen, Ville

    2016-01-01

    The origin of the idea of moving objects by acoustic vibration can be traced back to 1787, when Ernst Chladni reported the first detailed studies on the aggregation of sand onto nodal lines of a vibrating plate. Since then and to this date, the prevailing view has been that the particle motion out of nodal lines is random, implying uncontrollability. But how random really is the out-of-nodal-lines motion on a Chladni plate? Here we show that the motion is sufficiently regular to be statistically modelled, predicted and controlled. By playing carefully selected musical notes, we can control the position of multiple objects simultaneously and independently using a single acoustic actuator. Our method allows independent trajectory following, pattern transformation and sorting of multiple miniature objects in a wide range of materials, including electronic components, water droplets loaded on solid carriers, plant seeds, candy balls and metal parts. PMID:27611347

  10. Controlling the motion of multiple objects on a Chladni plate.

    PubMed

    Zhou, Quan; Sariola, Veikko; Latifi, Kourosh; Liimatainen, Ville

    2016-09-09

    The origin of the idea of moving objects by acoustic vibration can be traced back to 1787, when Ernst Chladni reported the first detailed studies on the aggregation of sand onto nodal lines of a vibrating plate. Since then and to this date, the prevailing view has been that the particle motion out of nodal lines is random, implying uncontrollability. But how random really is the out-of-nodal-lines motion on a Chladni plate? Here we show that the motion is sufficiently regular to be statistically modelled, predicted and controlled. By playing carefully selected musical notes, we can control the position of multiple objects simultaneously and independently using a single acoustic actuator. Our method allows independent trajectory following, pattern transformation and sorting of multiple miniature objects in a wide range of materials, including electronic components, water droplets loaded on solid carriers, plant seeds, candy balls and metal parts.

  11. Controlling the motion of multiple objects on a Chladni plate

    NASA Astrophysics Data System (ADS)

    Zhou, Quan; Sariola, Veikko; Latifi, Kourosh; Liimatainen, Ville

    2016-09-01

    The origin of the idea of moving objects by acoustic vibration can be traced back to 1787, when Ernst Chladni reported the first detailed studies on the aggregation of sand onto nodal lines of a vibrating plate. Since then and to this date, the prevailing view has been that the particle motion out of nodal lines is random, implying uncontrollability. But how random really is the out-of-nodal-lines motion on a Chladni plate? Here we show that the motion is sufficiently regular to be statistically modelled, predicted and controlled. By playing carefully selected musical notes, we can control the position of multiple objects simultaneously and independently using a single acoustic actuator. Our method allows independent trajectory following, pattern transformation and sorting of multiple miniature objects in a wide range of materials, including electronic components, water droplets loaded on solid carriers, plant seeds, candy balls and metal parts.

  12. Micro manipulator motion control to counteract macro manipulator structural vibrations

    SciTech Connect

    Lew, J.Y.; Trudnowski, D.J.; Evans, M.S.; Bennett, D.W.

    1995-02-01

    Inertial force damping control by micro manipulator modulation is proposed to suppress the vibrations of a micro/macro manipulator system. The proposed controller, developed using classical control theory, is added to the existing control system. The proposed controller uses real-time measurements of macro manipulator flexibility to adjust the motion of the micro manipulator to counteract structural vibrations. Experimental studies using an existing micro/macro flexible link manipulator testbed demonstrate the effectiveness of the proposed approach to suppression of vibrations in the macro/micro manipulator system using micro-manipulator-based inertial active damping control.

  13. Discrete Event Supervisory Control and Nonlinear Motion Control for DoD and Industrial Systems

    DTIC Science & Technology

    2014-03-17

    Nonlinear Motion Control for DoD and Industrial Systems 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 611102 6. AUTHORS 5d. PROJECT NUMBER FrankL...Supervisory Control and Nonlinear Motion Control for DoD and Industrial Systems Report Title This grant focuses on the design of advanced control systems for...initiative in Distributed Control of Networked Heterogeneous Teams. Methods for cooperative control of teams are being developed including discrete

  14. Controllable motion of optical vortex arrays using electromagnetically induced transparency.

    PubMed

    Shwa, David; Shtranvasser, Evgeny; Shalibo, Yoni; Katz, Nadav

    2012-10-22

    We demonstrate control of the collective motion of an optical vortex array using an electromagnetically induced transparency media. Scanning the frequency detuning between the pump and probe fields changes the susceptibility of the media, producing a unique effective diffraction of the vortex array for each detuning. We measure several experimental configurations and compare them to numerical simulations.

  15. Optimal control of the ballistic motion of Airy beams.

    PubMed

    Hu, Yi; Zhang, Peng; Lou, Cibo; Huang, Simon; Xu, Jingjun; Chen, Zhigang

    2010-07-01

    We demonstrate the projectile motion of two-dimensional truncated Airy beams in a general ballistic trajectory with controllable range and height. We show that the peak beam intensity can be delivered to any desired location along the trajectory as well as repositioned to a given target after displacement due to propagation through disordered or turbulent media.

  16. Voltage Controlled Magnetic Skyrmion Motion for Racetrack Memory

    PubMed Central

    Kang, Wang; Huang, Yangqi; Zheng, Chentian; Lv, Weifeng; Lei, Na; Zhang, Youguang; Zhang, Xichao; Zhou, Yan; Zhao, Weisheng

    2016-01-01

    Magnetic skyrmion, vortex-like swirling topologically stable spin configurations, is appealing as information carrier for future nanoelectronics, owing to the stability, small size and extremely low driving current density. One of the most promising applications of skyrmion is to build racetrack memory (RM). Compared to domain wall-based RM (DW-RM), skyrmion-based RM (Sky-RM) possesses quite a few benefits in terms of energy, density and speed etc. Until now, the fundamental behaviors, including nucleation/annihilation, motion and detection of skyrmion have been intensively investigated. However, one indispensable function, i.e., pinning/depinning of skyrmion still remains an open question and has to be addressed before applying skyrmion for RM. Furthermore, Current research mainly focuses on physical investigations, whereas the electrical design and evaluation are still lacking. In this work, we aim to promote the development of Sky-RM from fundamental physics to realistic electronics. First, we investigate the pinning/depinning characteristics of skyrmion in a nanotrack with the voltage-controlled magnetic anisotropy (VCMA) effect. Then, we propose a compact model and design framework of Sky-RM for electrical evaluation. This work completes the elementary memory functionality of Sky-RM and fills the technical gap between the physicists and electronic engineers, making a significant step forward for the development of Sky-RM. PMID:26975697

  17. Voltage Controlled Magnetic Skyrmion Motion for Racetrack Memory

    NASA Astrophysics Data System (ADS)

    Kang, Wang; Huang, Yangqi; Zheng, Chentian; Lv, Weifeng; Lei, Na; Zhang, Youguang; Zhang, Xichao; Zhou, Yan; Zhao, Weisheng

    2016-03-01

    Magnetic skyrmion, vortex-like swirling topologically stable spin configurations, is appealing as information carrier for future nanoelectronics, owing to the stability, small size and extremely low driving current density. One of the most promising applications of skyrmion is to build racetrack memory (RM). Compared to domain wall-based RM (DW-RM), skyrmion-based RM (Sky-RM) possesses quite a few benefits in terms of energy, density and speed etc. Until now, the fundamental behaviors, including nucleation/annihilation, motion and detection of skyrmion have been intensively investigated. However, one indispensable function, i.e., pinning/depinning of skyrmion still remains an open question and has to be addressed before applying skyrmion for RM. Furthermore, Current research mainly focuses on physical investigations, whereas the electrical design and evaluation are still lacking. In this work, we aim to promote the development of Sky-RM from fundamental physics to realistic electronics. First, we investigate the pinning/depinning characteristics of skyrmion in a nanotrack with the voltage-controlled magnetic anisotropy (VCMA) effect. Then, we propose a compact model and design framework of Sky-RM for electrical evaluation. This work completes the elementary memory functionality of Sky-RM and fills the technical gap between the physicists and electronic engineers, making a significant step forward for the development of Sky-RM.

  18. Voltage Controlled Magnetic Skyrmion Motion for Racetrack Memory.

    PubMed

    Kang, Wang; Huang, Yangqi; Zheng, Chentian; Lv, Weifeng; Lei, Na; Zhang, Youguang; Zhang, Xichao; Zhou, Yan; Zhao, Weisheng

    2016-03-15

    Magnetic skyrmion, vortex-like swirling topologically stable spin configurations, is appealing as information carrier for future nanoelectronics, owing to the stability, small size and extremely low driving current density. One of the most promising applications of skyrmion is to build racetrack memory (RM). Compared to domain wall-based RM (DW-RM), skyrmion-based RM (Sky-RM) possesses quite a few benefits in terms of energy, density and speed etc. Until now, the fundamental behaviors, including nucleation/annihilation, motion and detection of skyrmion have been intensively investigated. However, one indispensable function, i.e., pinning/depinning of skyrmion still remains an open question and has to be addressed before applying skyrmion for RM. Furthermore, Current research mainly focuses on physical investigations, whereas the electrical design and evaluation are still lacking. In this work, we aim to promote the development of Sky-RM from fundamental physics to realistic electronics. First, we investigate the pinning/depinning characteristics of skyrmion in a nanotrack with the voltage-controlled magnetic anisotropy (VCMA) effect. Then, we propose a compact model and design framework of Sky-RM for electrical evaluation. This work completes the elementary memory functionality of Sky-RM and fills the technical gap between the physicists and electronic engineers, making a significant step forward for the development of Sky-RM.

  19. Guaranteeing Isochronous Control of Networked Motion Control Systems Using Phase Offset Adjustment

    PubMed Central

    Kim, Ikhwan; Kim, Taehyoun

    2015-01-01

    Guaranteeing isochronous transfer of control commands is an essential function for networked motion control systems. The adoption of real-time Ethernet (RTE) technologies may be profitable in guaranteeing deterministic transfer of control messages. However, unpredictable behavior of software in the motion controller often results in unexpectedly large deviation in control message transmission intervals, and thus leads to imprecise motion. This paper presents a simple and efficient heuristic to guarantee the end-to-end isochronous control with very small jitter. The key idea of our approach is to adjust the phase offset of control message transmission time in the motion controller by investigating the behavior of motion control task. In realizing the idea, we performed a pre-runtime analysis to determine a safe and reliable phase offset and applied the phase offset to the runtime code of motion controller by customizing an open-source based integrated development environment (IDE). We also constructed an EtherCAT-based motion control system testbed and performed extensive experiments on the testbed to verify the effectiveness of our approach. The experimental results show that our heuristic is highly effective even for low-end embedded controller implemented in open-source software components under various configurations of control period and the number of motor drives. PMID:26076407

  20. Guaranteeing Isochronous Control of Networked Motion Control Systems Using Phase Offset Adjustment.

    PubMed

    Kim, Ikhwan; Kim, Taehyoun

    2015-06-12

    Guaranteeing isochronous transfer of control commands is an essential function for networked motion control systems. The adoption of real-time Ethernet (RTE) technologies may be profitable in guaranteeing deterministic transfer of control messages. However, unpredictable behavior of software in the motion controller often results in unexpectedly large deviation in control message transmission intervals, and thus leads to imprecise motion. This paper presents a simple and efficient heuristic to guarantee the end-to-end isochronous control with very small jitter. The key idea of our approach is to adjust the phase offset of control message transmission time in the motion controller by investigating the behavior of motion control task. In realizing the idea, we performed a pre-runtime analysis to determine a safe and reliable phase offset and applied the phase offset to the runtime code of motion controller by customizing an open-source based integrated development environment (IDE). We also constructed an EtherCAT-based motion control system testbed and performed extensive experiments on the testbed to verify the effectiveness of our approach. The experimental results show that our heuristic is highly effective even for low-end embedded controller implemented in open-source software components under various configurations of control period and the number of motor drives.

  1. Stepping-Motion Motor-Control Subsystem For Testing Bearings

    NASA Technical Reports Server (NTRS)

    Powers, Charles E.

    1992-01-01

    Control subsystem closed-loop angular-position-control system causing motor and bearing under test to undergo any of variety of continuous or stepping motions. Also used to test bearing-and-motor assemblies, motors, angular-position sensors including rotating shafts, and like. Monitoring subsystem gathers data used to evaluate performance of bearing or other article under test. Monitoring subsystem described in article, "Monitoring Subsystem For Testing Bearings" (GSC-13432).

  2. An improved adaptive control for repetitive motion of robots

    NASA Technical Reports Server (NTRS)

    Pourboghrat, F.

    1989-01-01

    An adaptive control algorithm is proposed for a class of nonlinear systems, such as robotic manipulators, which is capable of improving its performance in repetitive motions. When the task is repeated, the error between the desired trajectory and that of the system is guaranteed to decrease. The design is based on the combination of a direct adaptive control and a learning process. This method does not require any knowledge of the dynamic parameters of the system.

  3. Applications of control theory

    NASA Technical Reports Server (NTRS)

    Taft, C. K.; Pokoski, J. L.; Murdoch, J. B.; Limbert, D. E.; Alperi, R. W.

    1972-01-01

    Applications of control theory are considered in the areas of decoupling and wake steering control of submersibles, a method of electrohydraulic conversion with no moving parts, and socio-economic system modelling.

  4. Evaluation of Grasping Motion Using a Virtual Prosthetic Control System

    NASA Astrophysics Data System (ADS)

    Fukuda, Osamu; Bu, Nan; Ueno, Naohiro

    Electromyogram (EMG) signals can be measured from human muscles and can be used to anticipate movements. In fact, many researchers have tried to use these signals as an interface tool for a prosthetic hand. However, most of these studies focused on the discrimination performance of the EMG signals, and only discussed the control method for the prosthetic hand. Evaluation of the operating performance was seldom reported. This paper proposes a virtual prosthetic control system and presents the analyses of a grasp motion under two different EMG control methods: on/off control and proportional control. The proportional control is able to proportionally control the grasping velocity based on the amplitude of the EMG signal. The on/off control controls the hand at a uniform rate while the amplitude of the EMG signal is greater than a predefined threshold. We conducted experiments with five subjects, and confirmed the usefulness of the developed system.

  5. Polarimetric optical fiber sensor for weight-in-motion applications

    NASA Astrophysics Data System (ADS)

    Kosmowski, Bogdan B.; Mazikowski, Adam; Wierzba, Pawel

    1999-04-01

    Stress sensors dedicated for Weigh-in-Motion of road vehicles should exhibit high dynamic range, good accuracy and repeatability, as well as long service life. One of the most promising group of sensors for this application are polarimetric sensors, due to their simplicity and high sensitivity. Preliminary measurements of the optical fiber properties in this application resulted in significant hysteresis being observed even for relatively low stress, which is probably caused by the cladding properties or by the construction of the modulator used in the measurement.

  6. Hummingbirds control hovering flight by stabilizing visual motion

    PubMed Central

    Goller, Benjamin; Altshuler, Douglas L.

    2014-01-01

    Relatively little is known about how sensory information is used for controlling flight in birds. A powerful method is to immerse an animal in a dynamic virtual reality environment to examine behavioral responses. Here, we investigated the role of vision during free-flight hovering in hummingbirds to determine how optic flow—image movement across the retina—is used to control body position. We filmed hummingbirds hovering in front of a projection screen with the prediction that projecting moving patterns would disrupt hovering stability but stationary patterns would allow the hummingbird to stabilize position. When hovering in the presence of moving gratings and spirals, hummingbirds lost positional stability and responded to the specific orientation of the moving visual stimulus. There was no loss of stability with stationary versions of the same stimulus patterns. When exposed to a single stimulus many times or to a weakened stimulus that combined a moving spiral with a stationary checkerboard, the response to looming motion declined. However, even minimal visual motion was sufficient to cause a loss of positional stability despite prominent stationary features. Collectively, these experiments demonstrate that hummingbirds control hovering position by stabilizing motions in their visual field. The high sensitivity and persistence of this disruptive response is surprising, given that the hummingbird brain is highly specialized for sensory processing and spatial mapping, providing other potential mechanisms for controlling position. PMID:25489117

  7. Camera systems in human motion analysis for biomedical applications

    NASA Astrophysics Data System (ADS)

    Chin, Lim Chee; Basah, Shafriza Nisha; Yaacob, Sazali; Juan, Yeap Ewe; Kadir, Aida Khairunnisaa Ab.

    2015-05-01

    Human Motion Analysis (HMA) system has been one of the major interests among researchers in the field of computer vision, artificial intelligence and biomedical engineering and sciences. This is due to its wide and promising biomedical applications, namely, bio-instrumentation for human computer interfacing and surveillance system for monitoring human behaviour as well as analysis of biomedical signal and image processing for diagnosis and rehabilitation applications. This paper provides an extensive review of the camera system of HMA, its taxonomy, including camera types, camera calibration and camera configuration. The review focused on evaluating the camera system consideration of the HMA system specifically for biomedical applications. This review is important as it provides guidelines and recommendation for researchers and practitioners in selecting a camera system of the HMA system for biomedical applications.

  8. Motion Control for Nonholonomic Systems on Matrix Lie Groups

    DTIC Science & Technology

    1998-01-01

    representations of systems on a certain nilpotent matrix group. After studying the technique of nilpotentization in the setting of systems on matrix ...the technique of nilpotentization in the setting of systems on matrix Lie groups we show how motion control laws derived for nilpotent systems can be...of systems on a certain nilpotent matrix group. After studying the technique of nilpotentization in the setting of systems on matrix Lie groups we show

  9. Topography-Dependent Motion Compensation: Application to UAVSAR Data

    NASA Technical Reports Server (NTRS)

    Jones, Cathleen E.; Hensley, Scott; Michel, Thierry

    2009-01-01

    The UAVSAR L-band synthetic aperture radar system has been designed for repeat track interferometry in support of Earth science applications that require high-precision measurements of small surface deformations over timescales from hours to years. Conventional motion compensation algorithms, which are based upon assumptions of a narrow beam and flat terrain, yield unacceptably large errors in areas with even moderate topographic relief, i.e., in most areas of interest. This often limits the ability to achieve sub-centimeter surface change detection over significant portions of an acquired scene. To reduce this source of error in the interferometric phase, we have implemented an advanced motion compensation algorithm that corrects for the scene topography and radar beam width. Here we discuss the algorithm used, its implementation in the UAVSAR data processor, and the improvement in interferometric phase and correlation achieved in areas with significant topographic relief.

  10. Integration of commercial video motion detection into USAF flightline applications

    NASA Astrophysics Data System (ADS)

    Reis, John M.; Resca, Philip J.

    1997-02-01

    A short duration evaluation of a variety of commercially available Video Motion Detection products served to demonstrate application in detecting intrusion into protected areas of a military flightline. To be effective on a military flightline requires coverage over wide areas, adaptability to thermal imagery and ease of operator use. Opportunities exist to incorporate panning cameras with video motion detection to expand the awareness of Air Force Security Police. The interest in maximizing the utilization of relatively expensive and highly capable thermal imager cameras makes this a high interest priority. In the evaluation, the available products demonstrated an ability to perform intrusion detection, but flexibility in set-up and operation were seen as areas where improvement will be welcome.

  11. Topography-Dependent Motion Compensation: Application to UAVSAR Data

    NASA Technical Reports Server (NTRS)

    Jones, Cathleen E.; Hensley, Scott; Michel, Thierry

    2009-01-01

    The UAVSAR L-band synthetic aperture radar system has been designed for repeat track interferometry in support of Earth science applications that require high-precision measurements of small surface deformations over timescales from hours to years. Conventional motion compensation algorithms, which are based upon assumptions of a narrow beam and flat terrain, yield unacceptably large errors in areas with even moderate topographic relief, i.e., in most areas of interest. This often limits the ability to achieve sub-centimeter surface change detection over significant portions of an acquired scene. To reduce this source of error in the interferometric phase, we have implemented an advanced motion compensation algorithm that corrects for the scene topography and radar beam width. Here we discuss the algorithm used, its implementation in the UAVSAR data processor, and the improvement in interferometric phase and correlation achieved in areas with significant topographic relief.

  12. What Is Being Done to Control Motion Sickness?

    NASA Technical Reports Server (NTRS)

    Hall, Y. D.

    1985-01-01

    AFT (Autogenic Feedback Training) involves practicing a series of mental exercises to speed up or slow down the control of autonomic activity. This produces a reduced tendency for autonomic activity levels to diverge from baseline (at rest) under stressful motion-sickness-inducing conditions. Subjects conditions. Subjects engaged in applying AFT exercises are required to closely monitor their own bodily sensations during motion-sickness-eliciting tests. These tests include the Coriolis Sickness Susceptibility Index (CSSI), which consists of sitting a subject into a rotating chair that moves at various speeds while a visual background turns at differing speeds and directions, and the Vertical Acceleration Rotation Device (VARD) test, which involves the placing of a subject in a drum that moves in an upward and downward motion until he or she is sick, while simultaneously monitoring the subject's vital signs. These tests provide investigators with evidence of slight changes in autonomic activities such as increases in heart rate, skin temperature, and sweat. All of these symptoms occur in subjects that experience bodily weakness or discomfort with the onset of motion sickness.

  13. Motion Controlled Gait Enhancing Mobile Shoe for Rehabilitation

    PubMed Central

    Handzic, Ismet; Vasudevan, Erin V.; Reed, Kyle B.

    2011-01-01

    Walking on a split-belt treadmill, which has two belts that can be run at different speeds, has been shown to improve walking patterns post-stroke. However, these improvements are only temporarily retained once individuals transition to walking over ground. We hypothesize that longer-lasting effects would be observed if the training occurred during natural walking over ground, as opposed to on a treadmill. In order to study such long-term effects, we have developed a mobile and portable device which can simulate the same gait altering movements experienced on a split-belt treadmill. The new motion controlled gait enhancing mobile shoe improves upon the previous version’s drawbacks. This version of the GEMS has motion that is continuous, smooth, and regulated with on-board electronics. A vital component of this new design is the Archimedean spiral wheel shape that redirects the wearer’s downward force into a horizontal backward motion. The design is passive and does not utilize any motors. Its motion is regulated only by a small magnetic particle brake. Further experimentation is needed to evaluate the long-term after-effects. PMID:22275620

  14. Motion tracking in infrared imaging for quantitative medical diagnostic applications

    NASA Astrophysics Data System (ADS)

    Cheng, Tze-Yuan; Herman, Cila

    2014-01-01

    In medical applications, infrared (IR) thermography is used to detect and examine the thermal signature of skin abnormalities by quantitatively analyzing skin temperature in steady state conditions or its evolution over time, captured in an image sequence. However, during the image acquisition period, the involuntary movements of the patient are unavoidable, and such movements will undermine the accuracy of temperature measurement for any particular location on the skin. In this study, a tracking approach using a template-based algorithm is proposed, to follow the involuntary motion of the subject in the IR image sequence. The motion tacking will allow to associate a temperature evolution to each spatial location on the body while the body moves relative to the image frame. The affine transformation model is adopted to estimate the motion parameters of the template image. The Lucas-Kanade algorithm is applied to search for the optimized parameters of the affine transformation. A weighting mask is incorporated into the algorithm to ensure its tracking robustness. To evaluate the feasibility of the tracking approach, two sets of IR image sequences with random in-plane motion were tested in our experiments. A steady-state (no heating or cooling) IR image sequence in which the skin temperature is in equilibrium with the environment was considered first. The thermal recovery IR image sequence, acquired when the skin is recovering from 60-s cooling, was the second case analyzed. By proper selection of the template image along with template update, satisfactory tracking results were obtained for both IR image sequences. The achieved tracking accuracies are promising in terms of satisfying the demands imposed by clinical applications of IR thermography.

  15. Optimal robust motion controller design using multiobjective genetic algorithm.

    PubMed

    Sarjaš, Andrej; Svečko, Rajko; Chowdhury, Amor

    2014-01-01

    This paper describes the use of a multiobjective genetic algorithm for robust motion controller design. Motion controller structure is based on a disturbance observer in an RIC framework. The RIC approach is presented in the form with internal and external feedback loops, in which an internal disturbance rejection controller and an external performance controller must be synthesised. This paper involves novel objectives for robustness and performance assessments for such an approach. Objective functions for the robustness property of RIC are based on simple even polynomials with nonnegativity conditions. Regional pole placement method is presented with the aims of controllers' structures simplification and their additional arbitrary selection. Regional pole placement involves arbitrary selection of central polynomials for both loops, with additional admissible region of the optimized pole location. Polynomial deviation between selected and optimized polynomials is measured with derived performance objective functions. A multiobjective function is composed of different unrelated criteria such as robust stability, controllers' stability, and time-performance indexes of closed loops. The design of controllers and multiobjective optimization procedure involve a set of the objectives, which are optimized simultaneously with a genetic algorithm-differential evolution.

  16. Motion Control of the Soccer Robot Based on Fuzzy Logic

    NASA Astrophysics Data System (ADS)

    Coman, Daniela; Ionescu, Adela

    2009-08-01

    Robot soccer is a challenging platform for multi-agent research, involving topics such as real-time image processing and control, robot path planning, obstacle avoidance and machine learning. The conventional robot control consists of methods for path generation and path following. When a robot moves away the estimated path, it must return immediately, and while doing so, the obstacle avoidance behavior and the effectiveness of such a path are not guaranteed. So, motion control is a difficult task, especially in real time and high speed control. This paper describes the use of fuzzy logic control for the low level motion of a soccer robot. Firstly, the modelling of the soccer robot is presented. The soccer robot based on MiroSoT Small Size league is a differential-drive mobile robot with non-slipping and pure-rolling. Then, the design of fuzzy controller is describes. Finally, the computer simulations in MATLAB Simulink show that proposed fuzzy logic controller works well.

  17. Optimal Robust Motion Controller Design Using Multiobjective Genetic Algorithm

    PubMed Central

    Svečko, Rajko

    2014-01-01

    This paper describes the use of a multiobjective genetic algorithm for robust motion controller design. Motion controller structure is based on a disturbance observer in an RIC framework. The RIC approach is presented in the form with internal and external feedback loops, in which an internal disturbance rejection controller and an external performance controller must be synthesised. This paper involves novel objectives for robustness and performance assessments for such an approach. Objective functions for the robustness property of RIC are based on simple even polynomials with nonnegativity conditions. Regional pole placement method is presented with the aims of controllers' structures simplification and their additional arbitrary selection. Regional pole placement involves arbitrary selection of central polynomials for both loops, with additional admissible region of the optimized pole location. Polynomial deviation between selected and optimized polynomials is measured with derived performance objective functions. A multiobjective function is composed of different unrelated criteria such as robust stability, controllers' stability, and time-performance indexes of closed loops. The design of controllers and multiobjective optimization procedure involve a set of the objectives, which are optimized simultaneously with a genetic algorithm—differential evolution. PMID:24987749

  18. Dual-arm generalized compliant motion with shared control

    NASA Astrophysics Data System (ADS)

    Backes, Paul G.

    1993-03-01

    A multiple arm generalized compliant motion robot control system governs dual multi-joint robot arms handling an object with both of the arms in accordance with input parameters governing plural respective behaviors to be exhibited by the robot in respective behavior spaces simultaneously. A move-squeeze decomposition processor computes actual move and squeeze decomposition forces based upon current robot force sensor outputs. A compliant motion processor transforms plural object position perturbations of the plural behaviors from the respective behavior spaces to a common space and computes a relative transformation to a behavior-commanded object position in accordance with the object position perturbations of the plural behaviors. A kinematics processor updates a transformation to a current commanded object position based upon the relative transformation to the behavior-commanded object position. A multiple arm squeeze control processor computes from appropriate squeeze force input parameters and from actual squeeze forces for each of the arms, a squeeze control position perturbation for each of the arms, to provide squeeze control. An inverse kinematics processor computes from the commanded object position transformation and from the squeeze control position perturbation, new robot joint angles, and controls respective joints of the robot arms in accordance with the new robot joint angles.

  19. Dual arm generalized compliant motion with shared control

    NASA Astrophysics Data System (ADS)

    Backes, Paul G.

    1993-03-01

    A multiple arm generalized compliant motion robot control system governs dual multi-joint robot arms handling an object with both of the arms in accordance with input parameters governing plural respective behaviors to be exhibited by the robot in respective behavior spaces simultaneously. A move-squeeze decomposition processor computes actual move and squeeze decomposition forces based upon current robot force sensor outputs. A compliant motion processor transforms plural object position perturbations of the plural behaviors from the respective behavior spaces to a common space and computes a relative transformation to a behavior-commanded object position in accordance with the object position perturbations of the plural behaviors. A kinematics processor updates a transformation to a current commanded object position based upon the relative transformation to the behavior-commanded object position. A multiple arm squeeze control processor computes from appropriate squeeze force input parameters and from actual squeeze forces for each of the arms, a squeeze control position perturbation for each of the arms, to provide squeeze control. An inverse kinematics processor computes from the commanded object position transformation and from the squeeze control position perturbation, new robot joint angles, and controls respective joints of the robot arms in accordance with the new robot joint angles.

  20. Active Motion Control of Tetrahymena pyriformis by Galvanotaxis and Geotaxis

    NASA Astrophysics Data System (ADS)

    Kim, Jihoon; Byun, Doyoung; Kim, Min Jun

    2013-11-01

    Recently, there has been increasing interest in the swimming behavior of microorganisms and biologically inspired micro-robots. These microorganisms naturally accompanied by complex motions. Therefore it is important to understand the flow characteristics as well as control mechanisms. One of eukaryotic cells, the protozoa are a diverse group of unicellular organisms, many of which are motile cilia. Motile cilia are cover on the surface of cell in large numbers and beat in oriented waves. Sequential beating motions of a single cilium form metachronal strokes, producing a propagation wave, and therefore the body is achieved propulsion force. So preliminary studies are achieved to understand the flow induced by swimming microorganisms. Based on hydrodynamic results, the follow study of a few micro-scale protozoa cell, such as the Tetrahymena pyriformis, has provided active or passive control into several external stimuli. In typical control methods, the galvanotaxis and geotaxis were adopted active and passive control, respectively. The validation of galvanotaxis is used DC and AC voltage. In terms of geotaxis, corrugated microstructures were used to control in the microchannel. This research was supported by the Ministry of Education, Science and Technology (MEST, 2011-0016461), National Science Foundation (NSF) CMMI Control Systems Program (#1000255) and Army Research Office (W911NF-11-1-0490).

  1. 14 CFR 29.779 - Motion and effect of cockpit controls.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Motion and effect of cockpit controls. 29... Accommodations § 29.779 Motion and effect of cockpit controls. Cockpit controls must be designed so that they... collective pitch control, must operate with a sense of motion which corresponds to the effect on the...

  2. 14 CFR 27.779 - Motion and effect of cockpit controls.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Motion and effect of cockpit controls. 27... Accommodations § 27.779 Motion and effect of cockpit controls. Cockpit controls must be designed so that they... collective pitch control, must operate with a sense of motion which corresponds to the effect on the...

  3. Experimental investigation of shaping disturbance observer design for motion control of precision mechatronic stages with resonances

    NASA Astrophysics Data System (ADS)

    Yang, Jin; Hu, Chuxiong; Zhu, Yu; Wang, Ze; Zhang, Ming

    2017-08-01

    In this paper, shaping disturbance observer (SDOB) is investigated for precision mechatronic stages with middle-frequency zero/pole type resonance to achieve good motion control performance in practical manufacturing situations. Compared with traditional standard disturbance observer (DOB), in SDOB a pole-zero cancellation based shaping filter is cascaded to the mechatronic stage plant to meet the challenge of motion control performance deterioration caused by actual resonance. Noting that pole-zero cancellation is inevitably imperfect and the controller may even consequently become unstable in practice, frequency domain stability analysis is conducted to find out how each parameter of the shaping filter affects the control stability. Moreover, the robust design criterion of the shaping filter, and the design procedure of SDOB, are both proposed to guide the actual design and facilitate practical implementation. The SDOB with the proposed design criterion is applied to a linear motor driven stage and a voice motor driven stage, respectively. Experimental results consistently validate the effectiveness nature of the proposed SDOB scheme in practical mechatronics motion applications. The proposed SDOB design actually could be an effective unit in the controller design for motion stages of mechanical manufacture equipments.

  4. Autonomous vehicle motion control, approximate maps, and fuzzy logic

    NASA Technical Reports Server (NTRS)

    Ruspini, Enrique H.

    1993-01-01

    Progress on research on the control of actions of autonomous mobile agents using fuzzy logic is presented. The innovations described encompass theoretical and applied developments. At the theoretical level, results of research leading to the combined utilization of conventional artificial planning techniques with fuzzy logic approaches for the control of local motion and perception actions are presented. Also formulations of dynamic programming approaches to optimal control in the context of the analysis of approximate models of the real world are examined. Also a new approach to goal conflict resolution that does not require specification of numerical values representing relative goal importance is reviewed. Applied developments include the introduction of the notion of approximate map. A fuzzy relational database structure for the representation of vague and imprecise information about the robot's environment is proposed. Also the central notions of control point and control structure are discussed.

  5. Autonomous vehicle motion control, approximate maps, and fuzzy logic

    NASA Technical Reports Server (NTRS)

    Ruspini, Enrique H.

    1993-01-01

    Progress on research on the control of actions of autonomous mobile agents using fuzzy logic is presented. The innovations described encompass theoretical and applied developments. At the theoretical level, results of research leading to the combined utilization of conventional artificial planning techniques with fuzzy logic approaches for the control of local motion and perception actions are presented. Also formulations of dynamic programming approaches to optimal control in the context of the analysis of approximate models of the real world are examined. Also a new approach to goal conflict resolution that does not require specification of numerical values representing relative goal importance is reviewed. Applied developments include the introduction of the notion of approximate map. A fuzzy relational database structure for the representation of vague and imprecise information about the robot's environment is proposed. Also the central notions of control point and control structure are discussed.

  6. Motion.

    ERIC Educational Resources Information Center

    Brand, Judith, Ed.

    2002-01-01

    This issue of Exploratorium Magazine focuses on the topic of motion. Contents include: (1) "First Word" (Zach Tobias); (2) "Cosmic Collisions" (Robert Irion); (3) "The Mobile Cell" (Karen E. Kalumuck); (4) "The Paths of Paths" (Steven Vogel); (5) "Fragments" (Pearl Tesler); (6) "Moving Pictures" (Amy Snyder); (7) "Plants on the Go" (Katharine…

  7. Motion.

    ERIC Educational Resources Information Center

    Gerhart, James B.; Nussbaum, Rudi H.

    This monograph was written for the Conference on the New Instructional Materials in Physics held at the University of Washington in summer, 1965. It is intended for use in an introductory course in college physics. It consists of an extensive qualitative discussion of motion followed by a detailed development of the quantitative methods needed to…

  8. Motion.

    ERIC Educational Resources Information Center

    Brand, Judith, Ed.

    2002-01-01

    This issue of Exploratorium Magazine focuses on the topic of motion. Contents include: (1) "First Word" (Zach Tobias); (2) "Cosmic Collisions" (Robert Irion); (3) "The Mobile Cell" (Karen E. Kalumuck); (4) "The Paths of Paths" (Steven Vogel); (5) "Fragments" (Pearl Tesler); (6) "Moving Pictures" (Amy Snyder); (7) "Plants on the Go" (Katharine…

  9. Pharmacology in space. Part 2. Controlling motion sickness

    NASA Technical Reports Server (NTRS)

    Lathers, C. M.; Charles, J. B.; Bungo, M. W.

    1989-01-01

    In this second article in the two-part series on pharmacology in space, Claire Lathers and colleagues discuss the pharmacology of drugs used to control motion sickness in space and note that the pharmacology of the 'ideal' agent has yet to be worked out. That motion sickness may impair the pharmacological action of a drug by interfering with its absorption and distribution because of alteration of physiology is a problem unique to pharmacology in space. The authors comment on the problem of designing suitable ground-based studies to evaluate the pharmacological effect of drugs to be used in space and discuss the use of salivary samples collected during space flight to allow pharmacokinetic evaluations necessary for non-invasive clinical drug monitoring.

  10. Pharmacology in space. Part 2. Controlling motion sickness

    NASA Technical Reports Server (NTRS)

    Lathers, C. M.; Charles, J. B.; Bungo, M. W.

    1989-01-01

    In this second article in the two-part series on pharmacology in space, Claire Lathers and colleagues discuss the pharmacology of drugs used to control motion sickness in space and note that the pharmacology of the 'ideal' agent has yet to be worked out. That motion sickness may impair the pharmacological action of a drug by interfering with its absorption and distribution because of alteration of physiology is a problem unique to pharmacology in space. The authors comment on the problem of designing suitable ground-based studies to evaluate the pharmacological effect of drugs to be used in space and discuss the use of salivary samples collected during space flight to allow pharmacokinetic evaluations necessary for non-invasive clinical drug monitoring.

  11. Influence of Vibrotactile Feedback on Controlling Tilt Motion After Spaceflight

    NASA Technical Reports Server (NTRS)

    Wood, S. J.; Rupert, A. H.; Vanya, R. D.; Esteves, J. T.; Clement, G.

    2011-01-01

    We hypothesize that adaptive changes in how inertial cues from the vestibular system are integrated with other sensory information leads to perceptual disturbances and impaired manual control following transitions between gravity environments. The primary goals of this ongoing post-flight investigation are to quantify decrements in manual control of tilt motion following short-duration spaceflight and to evaluate vibrotactile feedback of tilt as a sensorimotor countermeasure. METHODS. Data is currently being collected on 9 astronaut subjects during 3 preflight sessions and during the first 8 days after Shuttle landings. Variable radius centrifugation (216 deg/s, <20 cm radius) in a darkened room is utilized to elicit otolith reflexes in the lateral plane without concordant canal or visual cues. A Tilt-Translation Sled (TTS) is capable of synchronizing pitch tilt with fore-aft translation to align the resultant gravitoinertial vector with the longitudinal body axis, thereby eliciting canal reflexes without concordant otolith or visual cues. A simple 4 tactor system was implemented to provide feedback when tilt position exceeded predetermined levels in either device. Closed-loop nulling tasks are performed during random tilt steps or sum-of-sines (TTS only) with and without vibrotactile feedback of chair position. RESULTS. On landing day the manual control performance without vibrotactile feedback was reduced by >30% based on the gain or the amount of tilt disturbance successfully nulled. Manual control performance tended to return to baseline levels within 1-2 days following landing. Root-mean-square position error and tilt velocity were significantly reduced with vibrotactile feedback. CONCLUSIONS. These preliminary results are consistent with our hypothesis that adaptive changes in vestibular processing corresponds to reduced manual control performance following G-transitions. A simple vibrotactile prosthesis improves the ability to null out tilt motion within a

  12. A Digital Motion Control System for Large Telescopes

    NASA Astrophysics Data System (ADS)

    Hunter, T. R.; Wilson, R. W.; Kimberk, R.; Leiker, P. S.

    2001-05-01

    We have designed and programmed a digital motion control system for large telescopes, in particular, the 6-meter antennas of the Submillimeter Array on Mauna Kea. The system consists of a single robust, high-reliability microcontroller board which implements a two-axis velocity servo while monitoring and responding to critical safety parameters. Excellent tracking performance has been achieved with this system (0.3 arcsecond RMS at sidereal rate). The 24x24 centimeter four-layer printed circuit board contains a multitude of hardware devices: 40 digital inputs (for limit switches and fault indicators), 32 digital outputs (to enable/disable motor amplifiers and brakes), a quad 22-bit ADC (to read the motor tachometers), four 16-bit DACs (that provide torque signals to the motor amplifiers), a 32-LED status panel, a serial port to the LynxOS PowerPC antenna computer (RS422/460kbps), a serial port to the Palm Vx handpaddle (RS232/115kbps), and serial links to the low-resolution absolute encoders on the azimuth and elevation axes. Each section of the board employs independent ground planes and power supplies, with optical isolation on all I/O channels. The processor is an Intel 80C196KC 16-bit microcontroller running at 20MHz on an 8-bit bus. This processor executes an interrupt-driven, scheduler-based software system written in C and assembled into an EPROM with user-accessible variables stored in NVSRAM. Under normal operation, velocity update requests arrive at 100Hz from the position-loop servo process running independently on the antenna computer. A variety of telescope safety checks are performed at 279Hz including routine servicing of a 6 millisecond watchdog timer. Additional ADCs onboard the microcontroller monitor the winding temperature and current in the brushless three-phase drive motors. The PID servo gains can be dynamically changed in software. Calibration factors and software filters can be applied to the tachometer readings prior to the application of

  13. Controlling the Motion of Ferrofluid Droplets Using Surface Tension Gradients and Magnetoviscous Pinning.

    PubMed

    Ody, T; Panth, M; Sommers, A D; Eid, K F

    2016-07-12

    This work demonstrates the controlled motion and stopping of individual ferrofluid droplets due to a surface tension gradient and a uniform magnetic field. The surface tension gradients are created by patterning hydrophilic aluminum regions, shaped as wedges, on a hydrophobic copper surface. This pattern facilitates the spontaneous motion of water-based ferrofluid droplets down the length of the wedge toward the more hydrophilic aluminum end due to a net capillarity force created by the underlying surface wettability gradient. We observed that applying a magnetic field parallel to the surface tension gradient direction has little or no effect on the droplet's motion, while a moderate perpendicular magnetic field can stop the motion altogether effectively "pinning" the droplet. In the absence of the surface tension gradient, droplets elongate in the presence of a parallel field but do not travel. This control of the motion of individual droplets might lend itself to some biomedical and lab-on-a-chip applications. The directional dependence of the magnetoviscosity observed in this work is believed to be the consequence of the formation of nanoparticle chains in the fluid due to the existence of a minority of relatively larger magnetic particles.

  14. Motion artifact removal in FNIR spectroscopy for real-world applications

    NASA Astrophysics Data System (ADS)

    Devaraj, Ajit; Izzetoglu, Meltem; Izzetoglu, Kurtulus; Bunce, Scott C.; Li, Connie Y.; Onaral, Banu

    2004-12-01

    Near infrared spectroscopy as a neuroimaging modality is a recent development. Near infrared neuroimagers are typically safe, portable, relatively affordable and non-invasive. The ease of sensor setup and non-intrusiveness make functional near infrared (fNIR) imaging an ideal candidate for monitoring human cortical function in a wide range of real world situations. However optical signals are susceptible to motion-artifacts, hindering the application of fNIR in studies where subject mobility cannot be controlled. In this paper, we present a filtering framework for motion-artifact cancellation to facilitate the deployment of fNIR imaging in real-world scenarios. We simulate a generic field environment by having subjects walk on a treadmill while performing a cognitive task and demonstrate that measurements can be effectively cleaned of motion-artifacts.

  15. On Motion Planning and Control of Multi-Link Lightweight Robotic Manipulators

    NASA Technical Reports Server (NTRS)

    Cetinkunt, Sabri

    1987-01-01

    A general gross and fine motion planning and control strategy is needed for lightweight robotic manipulator applications such as painting, welding, material handling, surface finishing, and spacecraft servicing. The control problem of lightweight manipulators is to perform fast, accurate, and robust motions despite the payload variations, structural flexibility, and other environmental disturbances. Performance of the rigid manipulator model based computed torque and decoupled joint control methods are determined and simulated for the counterpart flexible manipulators. A counterpart flexible manipulator is defined as a manipulator which has structural flexibility, in addition to having the same inertial, geometric, and actuation properties of a given rigid manipulator. An adaptive model following control (AMFC) algorithm is developed to improve the performance in speed, accuracy, and robustness. It is found that the AMFC improves the speed performance by a factor of two over the conventional non-adaptive control methods for given accuracy requirements while proving to be more robust with respect to payload variations. Yet there are clear limitations on the performance of AMFC alone as well, which are imposed by the arm flexibility. In the search to further improve speed performance while providing a desired accuracy and robustness, a combined control strategy is developed. Furthermore, the problem of switching from one control structure to another during the motion and implementation aspects of combined control are discussed.

  16. The DESDEMONA Motion Facility: Applications for Space Research

    NASA Astrophysics Data System (ADS)

    Bles, Willem; Groen, Eric

    2009-11-01

    The research facility DESDEMONA features a unique motion platform, combining a fully gimbaled cabin with the capability of producing sustained g-loads. Originally designed for ground-based simulation as well as training of spatial disorientation in aviation, the motion capabilities are also interesting for other areas. In this paper we will provide examples of space-related research questions that can be addressed on DESDEMONA. Some questions are concerned with centrifugation as a means to create artificial gravity. For instance, with its variable radius and gimbaled cabin, DESDEMONA allows for studying possible trade-offs between g-load and angular velocity. Other questions relate to the effects of g-level transitions on the astronauts' well-being and performance. During the last two decades, research at TNO has shown that after prolonged exposure to centrifugation at 3 g astronauts experience the same vestibular adaptation symptoms as observed in real space flight. In DESDEMONA, the hyper-gravity stimulus can be applied and the consequences for control of simulated spacecraft can be examined in the same device. Furthermore, DESDEMONA also provides a `clinical' tool for vestibular examination of astronauts, and for the provocation and desensitization of motion sickness in unusual G-environments.

  17. Conditions of the Maximum Principle in the Problem of Optimal Control over an Aggregate of Dynamic Systems and Their Application to Solution of the Problems of Optimal Control of Spacecraft Motion

    NASA Astrophysics Data System (ADS)

    Grigoriev, I. S.; Grigoriev, K. G.

    2003-05-01

    The necessary first-order conditions of strong local optimality (conditions of maximum principle) are considered for the problems of optimal control over a set of dynamic systems. To derive them a method is suggested based on the Lagrange principle of removing constraints in the problems on a conditional extremum in a functional space. An algorithm of conversion from the problem of optimal control of an aggregate of dynamic systems to a multipoint boundary value problem is suggested for a set of systems of ordinary differential equations with the complete set of conditions necessary for its solution. An example of application of the methods and algorithm proposed is considered: the solution of the problem of constructing the trajectories of a spacecraft flight at a constant altitude above a preset area (or above a preset point) of a planet's surface in a vacuum (for a planet with atmosphere beyond the atmosphere). The spacecraft is launched from a certain circular orbit of a planet's satellite. This orbit is to be determined (optimized). Then the satellite is injected to the desired trajectory segment (or desired point) of a flyby above the planet's surface at a specified altitude. After the flyby the satellite is returned to the initial circular orbit. A method is proposed of correct accounting for constraints imposed on overload (mixed restrictions of inequality type) and on the distance from the planet center: extended (nonpointlike) intermediate (phase) restrictions of the equality type.

  18. LQR Controller for Toroidal Continuously Variable Transmission in Reverse Motion

    NASA Astrophysics Data System (ADS)

    Mensler, Michel; Kawabe, Taketoshi; Joe, Shinichiro

    The system considered in this paper is a Toroidal Continuously Variable Transmission (TCVT) system for cars. This system is unstable in reverse motion as some mechanical parts have been removed from the original one for cost reduction, and the gear ratio has to be regulated around its nominal value for car reverse motion. The control theory used here is the Linear Quadratic Regulator (LQR) associated to a gain-scheduling technique, as the TCVT system is nonlinear according to the car speed. Moreover, as the LQR method requires the entire TCVT state vector and as the only available signal is the gear ratio, a full-order observer is designed. In order to take the other nonlinearities of the system into account, the observer is nonlinear: a diffeomorphism is then used for converting the variables provided by the nonlinear observer into the needed variables. In order to verify the effectiveness and the robustness of the controller against the car speed and the torque shift disturbance phenomenon, several experiments with a test-bed and with an actual vehicle have been performed and showed the efficiency of the proposed controller.

  19. Learning Silhouette Features for Control of Human Motion

    DTIC Science & Technology

    2004-07-01

    machine learning algorithm during a preprocessing step. Sequences of motions that approximate the user’s actions are extracted from the motion database and scaled in time to match the speed of the user’s motion. We use swing dancing, an example of complex human motion, to demonstrate the effectiveness of our approach. We compare the results obtained with our approach to those obtained with a set of global features, Hu moments, and to ground truth measurements from a motion capture

  20. Research on Hybrid Seismic Response Control System for Motion Control of Two Span Bridge

    NASA Astrophysics Data System (ADS)

    Heo, G.; Kim, C.; Jeon, S.; Seo, S.; Jeon, J.

    2016-09-01

    In this paper, a hybrid seismic response control (HSRC) system was developed to control bridge motion caused by seismic load. It was aimed at optimum vibration control, composed of a rubber bearing of passive type and a MR-damper of semi-active type. The bridge model was built for experiment, a two-span bridge of 8.3 meters in length with the HSRC system put up on it. Then, inflicting El-centro seismic load on it, shaking table tests were carried out to confirm the system's validity. The experiments were conducted under the basic structure state (without an MR-damper applied) first, and then under the state with an MR-damper applied. It was also done under the basic structure state with a reinforced rubber bearing applied, then the passive on/off state of the HSRC system, and finally the semi-active state where the control algorithm was applied to the system. From the experiments, it was observed that collision rather increased when the MR-damper alone was applied, and also that the application of the HSRC system effectively prevented it from occurring. As a result, the HSRC system was proven to be effective in mitigating responses of the two-span bridge under seismic load.

  1. Effect of kinesio tape application on calf pain and ankle range of motion in duathletes.

    PubMed

    Merino-Marban, Rafael; Mayorga-Vega, Daniel; Fernandez-Rodriguez, Emilio

    2013-01-01

    The purpose of this study was to examine the effect of the kinesio tape immediately after its application and after a duathlon competition on calf pain and the ankle range of motion in duathletes. A sample of 28 duathletes (age 29.11 ± 10.35 years; body height 172.57 ± 6.17 cm; body mass 66.63 ± 9.01 kg; body mass index 22.29 ± 2.00 kg/m(2)) were recruited from the competitors in a duathlon sprint. The Numerical Pain Rating Scale and ankle dorsiflexion range of motion measures were obtained at baseline, immediately after taping and 10 to 15 minutes after ending the duathlon competition. The kinesio tape was applied on the calf of duathletes 20 to 90 minutes before the competition, only on one of their legs (experimental leg) with the other leg acting as a control (control leg) in a randomized order. According to the between-group comparison, no differences were found immediately after the application of the kinesio tape and after the competition in the ankle range of motion and calf pain. However, a significant difference from baseline to immediately after taping was found in the ankle range of motion in the experimental leg. Applying the kinesio tape on the calf seems to immediately increase ankle dorsiflexion range of motion, but not after a duathlon competition. Applying the kinesio tape on the calf does not reduce muscle pain immediately or after a duathlon competition, but it appears to control an increase in pain.

  2. Effect of Kinesio Tape Application on Calf Pain and Ankle Range of Motion in Duathletes

    PubMed Central

    Merino-Marban, Rafael; Mayorga-Vega, Daniel; Fernandez-Rodriguez, Emilio

    The purpose of this study was to examine the effect of the kinesio tape immediately after its application and after a duathlon competition on calf pain and the ankle range of motion in duathletes. A sample of 28 duathletes (age 29.11 ± 10.35 years; body height 172.57 ± 6.17 cm; body mass 66.63 ± 9.01 kg; body mass index 22.29 ± 2.00 kg/m 2 ) were recruited from the competitors in a duathlon sprint. The Numerical Pain Rating Scale and ankle dorsiflexion range of motion measures were obtained at baseline, immediately after taping and 10 to 15 minutes after ending the duathlon competition. The kinesio tape was applied on the calf of duathletes 20 to 90 minutes before the competition, only on one of their legs (experimental leg) with the other leg acting as a control (control leg) in a randomized order. According to the between-group comparison, no differences were found immediately after the application of the kinesio tape and after the competition in the ankle range of motion and calf pain. However, a significant difference from baseline to immediately after taping was found in the ankle range of motion in the experimental leg. Applying the kinesio tape on the calf seems to immediately increase ankle dorsiflexion range of motion, but not after a duathlon competition. Applying the kinesio tape on the calf does not reduce muscle pain immediately or after a duathlon competition, but it appears to control an increase in pain. PMID:24146713

  3. Adaptive Force Control For Compliant Motion Of A Robot

    NASA Technical Reports Server (NTRS)

    Seraji, Homayoun

    1995-01-01

    Two adaptive control schemes offer robust solutions to problem of stable control of forces of contact between robotic manipulator and objects in its environment. They are called "adaptive admittance control" and "adaptive compliance control." Both schemes involve use of force-and torque sensors that indicate contact forces. These schemes performed well when tested in computational simulations in which they were used to control seven-degree-of-freedom robot arm in executing contact tasks. Choice between admittance or compliance control is dictated by requirements of the application at hand.

  4. Motion control solution for new PLC-based standard development platform for VLT instrument control systems

    NASA Astrophysics Data System (ADS)

    Popovic, D.; Brast, R.; Di Lieto, N.; Kiekebusch, M.; Knudstrup, J.; Lucuix, C.

    2014-07-01

    More than a decade ago, due to obsolescence issues, ESO initiated the design and implementation of a custom-made CANbus based motion controller (CAN-RMC) to provide, together with a tailor-made software library (motor library), the motion control capabilities for the VME platform needed for the second generation VLT/VLTI instruments. The CAN-RMC controller has been successfully used in a number of VLT instruments but it has high production costs compared to the commercial off-the-shelf (COTS) industrial solutions available on the market today. In the scope of the selection of a new PLC-based platform for the VLT instrument control systems, ESO has evaluated motion control solutions from the company Beckhoff. This paper presents the investigation, implementation and testing of the PLC/TwinCAT/EtherCAT motion controllers for DC and stepper motors and their adaptation and integration into the VLT instrumentation framework. It reports functional and performance test results for the most typical use cases of astronomical instruments like initialization sequences, tracking, switch position detections, backslash compensation, brake handling, etc. In addition, it gives an overview of the main features of TwinCAT NC/PTP, PLCopen MC, EtherCAT motion control terminals and the engineering tools like TwinCAT Scope that are integrated into the development environment and simplify software development, testing and commissioning of motorized instrument functions.

  5. Active motion and load control of floating offshore wind turbines

    NASA Astrophysics Data System (ADS)

    Jalili, Kaveh

    The research in this thesis is focused on stabilization and load reduction of floating offshore wind turbine (FOWT) structures for both the fore-aft (pitch) and side-to-side (roll) directions. Based on the Tuned Mass Damper (TMD) and Active Vane concepts recently proposed, two composite actuation schemes are investigated. The first scheme is to apply the horizontal vane and vertical vane to platform pitch and roll, respectively, resulting in the so-called Double Vane Actuation (DVA) scheme. The second scheme is the combination of the TMD based pitch control and active vertical vane based roll control, resulting in the so-called Hybrid Actuation (HA) scheme. Simulation results of DVA show great reductions of motions and loads in the fore-aft and side-to-side directions. Performance of HA is investigated by extensive simulations based on the IEC61400-3 standard and results show significant and consistent motions and loads reductions in both FA and SS directions.

  6. Relative dynamics and motion control of nanosatellite formation flying

    NASA Astrophysics Data System (ADS)

    Pimnoo, Ammarin; Hiraki, Koju

    2016-04-01

    Orbit selection is a necessary factor in nanosatellite formation mission design/meanwhile, to keep the formation, it is necessary to consume fuel. Therefore, the best orbit design for nanosatellite formation flying should be one that requires the minimum fuel consumption. The purpose of this paper is to analyse orbit selection with respect to the minimum fuel consumption, to provide a convenient way to estimate the fuel consumption for keeping nanosatellite formation flying and to present a simplified method of formation control. The formation structure is disturbed by J2 gravitational perturbation and other perturbing accelerations such as atmospheric drag. First, Gauss' Variation Equations (GVE) are used to estimate the essential ΔV due to the J2 perturbation and atmospheric drag. The essential ΔV presents information on which orbit is good with respect to the minimum fuel consumption. Then, the linear equations which account for J2 gravitational perturbation of Schweighart-Sedwick are presented and used to estimate the fuel consumption to maintain the formation structure. Finally, the relative dynamics motion is presented as well as a simplified motion control of formation structure by using GVE.

  7. Manipulating motions of elastomer films by electrostatically-controlled aperiodicity

    NASA Astrophysics Data System (ADS)

    Shmuel, Gal; Pernas-Salomón, René

    2016-12-01

    We investigate the effect electrostatically-controlled aperiodicity has on the propagation of flexural waves in two-component elastomeric films. We first determine the static response of the film to a combination of an axial force and voltage over selected segments. Thus, in response to the accumulated charge, the elastomer confined geometrical and physical changes introduce aperiodicity in the film. We then develop the equation governing superposed flexural motions, accounting for the elastomer stiffening and static finite deformation. We adapt a stable matrix method based on this equation to compute the transmission characteristics of the film. Through numerical examples, we show that these characteristics significantly depend on which segments are actuated, i.e., on the resultant aperiodicity. These findings promise a new strategy to control elastic waves.

  8. [Bionic model for coordinated head-eye motion control].

    PubMed

    Mao, Xiaobo; Chen, Tiejun

    2011-10-01

    The relationships between eye movements and head movements of the primate during gaze shifts are analyzed in detail in the present paper. Applying the mechanisms of neurophysiology to engineering domain, we have improved the robot eye-head coordination. A bionic control strategy of coordinated head-eye motion was proposed. The processes of gaze shifts are composed of an initial fast phase followed by a slow phase. In the fast phase saccade eye movements and slow head movements were combined, which cooperate to bring gaze from an initial resting position toward the new target rapidly, while in the slow phase the gaze stability and target fixation were ensured by the action of the vestibulo-ocular reflex (VOR) where the eyes and head rotate by equal amplitudes in opposite directions. A bionic gaze control model was given. The simulation results confirmed the effectiveness of the model by comparing with the results of neurophysiology experiments.

  9. Intelligent motion control for linear piezoelectric ceramic motor drive.

    PubMed

    Wai, Rong-Jong; Lee, Jeng-Dao

    2004-10-01

    Since the dynamic characteristics of a linear piezoelectric ceramic motor (LPCM) are highly nonlinear and time varying, it is difficult to design a suitable motor drive and position controller that realizes accurate position control at all time. This study investigates a double-inductance double-capacitance (LLCC) resonant driving circuit and a sliding-mode fuzzy-neural-network control (SMFNNC) system for the motion control of an LPCM. First, the motor structure and LLCC driving circuit of an LPCM are introduced. The LLCC resonant inverter is designed to operate at an optimal switching frequency such that the output voltage will not be influenced by the variation of quality factor. Moreover, a SMFNNC system is designed to achieve favorable tracking performance without precise dynamic models being controlled. All adaptive learning algorithms in the SMFNNC system are derived in the sense of Lyapunov stability analysis, so that system-tracking stability can be guaranteed in the closed-loop system. The effectiveness of the proposed driving circuit and control system is verified by experimental results.

  10. Monolithic sensors for low frequency motion measurement and control of spacecrafts and satellites

    NASA Astrophysics Data System (ADS)

    Barone, F.; Giordano, G.; Acernese, F.; Romano, R.

    2016-10-01

    In this paper we describe the characteristics and performances of a monolithic sensor designed for low frequency motion measurement and control of spacecrafts and satellites, whose mechanics is based on the UNISA Folded Pendulum. The latter, developed for ground-based applications, exhibits unique features (compactness, lightness, scalability, low resonance frequency and high quality factor), consequence of the action of the gravitational force on its inertial mass. In this paper we introduce and discuss the general methodology used to extend the application of ground-based folded pendulums to space, also in total absence of gravity, still keeping all their peculiar features and characteristics.

  11. Development of a cost-effective PC-based motion control system

    SciTech Connect

    Hollar, D.L.

    1998-01-01

    A cost-effective PC-based motion control system was developed and evaluated for use on a laser welding system. The motion system is capable of X-Y simultaneous contouring and provides a rotary axis of motion also. The system motion paths can be specified in either Relative or Absolute motion. The PC controls all of the laser power supply and shutter I/O operations. All of the motion programming and operator interfacing is via the Windows {reg_sign}95 operating system.

  12. Towards controlling molecular motions in fluorescence microscopy and optical trapping: a spatiotemporal approach.

    PubMed

    Kumar De, Arijit; Goswami, Debabrata

    2011-09-26

    This account reviews some recent studies pursued in our group on several control experiments with important applications in (one-photon) confocal and two-photon fluorescence laser-scanning microscopy and optical trapping with laser tweezers. We explore the simultaneous control of internal and external (i.e. centre-of-mass motion) degrees of freedom, which require the coupling of various control parameters to result in the spatiotemporal control. Of particular interest to us is the implementation of such control schemes in living systems. A live cell is a system of a large number of different molecules which combine and interact to generate complex structures and functions. These combinations and interactions of molecules need to be choreographed perfectly in time and space to achieve intended intra-cellular functions. Spatiotemporal control promises to be a versatile tool for dynamical control of spatially manipulated bio-molecules.

  13. Towards controlling molecular motions in fluorescence microscopy and optical trapping: a spatiotemporal approach

    PubMed Central

    Kumar De, Arijit; Goswami, Debabrata

    2013-01-01

    This account reviews some recent studies pursued in our group on several control experiments with important applications in (one-photon) confocal and two-photon fluorescence laser-scanning microscopy and optical trapping with laser tweezers. We explore the simultaneous control of internal and external (i.e. centre-of-mass motion) degrees of freedom, which require the coupling of various control parameters to result in the spatiotemporal control. Of particular interest to us is the implementation of such control schemes in living systems. A live cell is a system of a large number of different molecules which combine and interact to generate complex structures and functions. These combinations and interactions of molecules need to be choreographed perfectly in time and space to achieve intended intra-cellular functions. Spatiotemporal control promises to be a versatile tool for dynamical control of spatially manipulated bio-molecules. PMID:23814326

  14. Applications of Displacement Speed and Virtual Velocity to Bedload Motion

    NASA Astrophysics Data System (ADS)

    Knapp, D. D.; Papanicolaou, A. N.

    2002-12-01

    The advances made in scientific visualization techniques have enhanced our capabilities of tracking sediment and measuring sediment rates. The focus of this study is to incorporate a new experimental approach to determine the displacement speed and the virtual velocity of particles rolling atop a well packed bed and provide a formula that describes the average speed of particles as a function of the particles? geometry and weight, settling velocity, and the frictional characteristics of flow. The displacement speed is the speed of a particle moving from one point of rest to another, while the virtual velocity is the velocity of a particle including its resting period. Such formulas are lacking because the emphasis, so far, has been placed in developing expressions that provide the displacement speed of particles during saltation only. The nature of the present study is experimental. As such, tests were performed in a laboratory flume so that flow and sediment conditions could be precisely controlled. The motion of spherical particles with diameters ranging from 8 mm to 25.4 mm was monitored under different flow conditions and bed roughness in a laboratory flume. The flow was varied between the incipient flow conditions and conditions representing general sediment motion in natural gravel bed rivers. Bed conditions varied from well packed spheres of 8 mm and 19 mm, to a well packed bed of gravel with a mean size of 6.5 mm. Overall, 42 experimental runs were conducted. The tests were repeated at least 15 times, or until flow and sediment data of statistical significance was established. A laboratory version of an Acoustic Doppler Velocimeter (ADV) and a Swoffer propeller meter were used to obtain velocity profiles through out the water depth. The velocity profiles were used in conjunction with the Clauser method to determine the friction velocity. Incipient flow conditions were determined based on a trial and error method and where defined as the conditions when a

  15. Relative roughness controls on incipient sediment motion in steep channels

    NASA Astrophysics Data System (ADS)

    Prancevic, J.; Lamb, M. P.; Fuller, B. M.

    2012-12-01

    For over eight decades, researchers have noted an appreciable increase in the nondimensional shear stress (Shields number) at initiation of fluvial bedload transport with increasing bed slope. The precise cause of the trend, however, is obscured by the covariance of several factors with increased slope: a greater downstream component of the gravity acting on the grains and fluid, changes in bed morphology, increased grainsize relative to the channel width that may lead to grain bridging, and increased grainsize relative to flow depth (relative roughness) that may change flow hydraulics and particle buoyancy. Here, we report on ongoing laboratory experiments spanning a wide range of bed slopes (2% to 67%) designed to isolate these variables and determine the true cause of heightened critical Shields numbers on steep slopes. First, we eliminated bed morphology as a factor by using only planar beds. To investigate the effect of grain bridging, we used two different channel widths, representing width-to-grainsize ratios of 23:1 and 9:1. Finally, to separate the effects of slope from relative roughness, we compared incipient motion conditions for acrylic particles (submerged specific gravity of 0.15) to natural siliciclastic gravel (submerged specific gravity of 1.65). Different particle densities allowed us to explore incipient motion as a function of relative roughness, independent of channel slope, because lighter particles move at shallower flow depths than heavier ones of the same size. Results show that both materials exhibit a positive trend between bed slope and critical Shields number despite the existence of planar beds for all slopes. Furthermore, changing the grainsize-to-width ratio had a negligible effect on this trend. For all slopes, the critical Shields number for bedload transport was higher for the acrylic particles than for gravel, indicating that relative roughness has a strong control on incipient sediment motion independent of channel slope. These

  16. Controlling motion prediction errors in radiotherapy with relevance vector machines.

    PubMed

    Dürichen, Robert; Wissel, Tobias; Schweikard, Achim

    2015-04-01

    Robotic radiotherapy can precisely ablate moving tumors when time latencies have been compensated. Recently, relevance vector machines (RVM), a probabilistic regression technique, outperformed six other prediction algorithms for respiratory compensation. The method has the distinct advantage that each predicted point is assumed to be drawn from a normal distribution. Second-order statistics, the predicted variance, were used to control RVM prediction error during a treatment and to construct hybrid prediction algorithms. First, the duty cycle and the precision were correlated to the variance by interrupting the treatment if the variance exceeds a threshold. Second, two hybrid algorithms based on the variance were developed, one consisting of multiple RVMs (HYB(RVM)) and the other of a combination between a wavelet-based least mean square algorithm (wLMS) and a RVM (HYB(wLMS-RVM)). The variance for different motion traces was analyzed to reveal a characteristic variance pattern which gives insight in what kind of prediction errors can be controlled by the variance. Limiting the variance by a threshold resulted in an increased precision with a decreased duty cycle. All hybrid algorithms showed an increased prediction accuracy compared to using only their individual algorithms. The best hybrid algorithm, HYB(RVM), can decrease the mean RMSE over all 304 motion traces from 0.18 mm for a linear RVM to 0.17 mm. The predicted variance was shown to be an efficient metric to control prediction errors, resulting in a more robust radiotherapy treatment. The hybrid algorithm HYB(RVM) could be translated to clinical practice. It does not require further parameters, can be completely parallelised and easily further extended.

  17. SISMA (Site of Italian Strong Motion Accelerograms): a Web-Database of Ground Motion Recordings for Engineering Applications

    SciTech Connect

    Scasserra, Giuseppe; Lanzo, Giuseppe; D'Elia, Beniamino; Stewart, Jonathan P.

    2008-07-08

    The paper describes a new website called SISMA, i.e. Site of Italian Strong Motion Accelerograms, which is an Internet portal intended to provide natural records for use in engineering applications for dynamic analyses of structural and geotechnical systems. SISMA contains 247 three-component corrected motions recorded at 101 stations from 89 earthquakes that occurred in Italy in the period 1972-2002. The database of strong motion accelerograms was developed in the framework of a joint project between Sapienza University of Rome and University of California at Los Angeles (USA) and is described elsewhere. Acceleration histories and pseudo-acceleration response spectra (5% damping) are available for download from the website. Recordings can be located using simple search parameters related to seismic source and the recording station (e.g., magnitude, V{sub s30}, etc) as well as ground motion characteristics (e.g. peak ground acceleration, peak ground velocity, peak ground displacement, Arias intensity, etc.)

  18. SISMA (Site of Italian Strong Motion Accelerograms): a Web-Database of Ground Motion Recordings for Engineering Applications

    NASA Astrophysics Data System (ADS)

    Scasserra, Giuseppe; Lanzo, Giuseppe; Stewart, Jonathan P.; D'Elia, Beniamino

    2008-07-01

    The paper describes a new website called SISMA, i.e. Site of Italian Strong Motion Accelerograms, which is an Internet portal intended to provide natural records for use in engineering applications for dynamic analyses of structural and geotechnical systems. SISMA contains 247 three-component corrected motions recorded at 101 stations from 89 earthquakes that occurred in Italy in the period 1972-2002. The database of strong motion accelerograms was developed in the framework of a joint project between Sapienza University of Rome and University of California at Los Angeles (USA) and is described elsewhere. Acceleration histories and pseudo-acceleration response spectra (5% damping) are available for download from the website. Recordings can be located using simple search parameters related to seismic source and the recording station (e.g., magnitude, Vs30, etc) as well as ground motion characteristics (e.g. peak ground acceleration, peak ground velocity, peak ground displacement, Arias intensity, etc.).

  19. Motion-mode energy method for vehicle dynamics analysis and control

    NASA Astrophysics Data System (ADS)

    Zhang, Nong; Wang, Lifu; Du, Haiping

    2014-01-01

    Vehicle motion and vibration control is a fundamental motivation for the development of advanced vehicle suspension systems. In a vehicle-fixed coordinate system, the relative motions of the vehicle between body and wheel can be classified into several dynamic stages based on energy intensity, and can be decomposed into sets of uncoupled motion-modes according to modal parameters. Vehicle motions are coupled, but motion-modes are orthogonal. By detecting and controlling the predominating vehicle motion-mode, the system cost and energy consumption of active suspensions could be reduced. A motion-mode energy method (MEM) is presented in this paper to quantify the energy contribution of each motion-mode to vehicle dynamics in real time. The control of motion-modes is prioritised according to the level of motion-mode energy. Simulation results on a 10 degree-of-freedom nonlinear full-car model with the magic-formula tyre model illustrate the effectiveness of the proposed MEM. The contribution of each motion-mode to the vehicle's dynamic behaviour is analysed under different excitation inputs from road irregularities, directional manoeuvres and braking. With the identified dominant motion-mode, novel cost-effective suspension systems, such as active reconfigurable hydraulically interconnected suspension, can possibly be used to control full-car motions with reduced energy consumption. Finally, discussion, conclusions and suggestions for future work are provided.

  20. Attitude motion of a non-attitude-controlled cylindrical satellite

    NASA Technical Reports Server (NTRS)

    Wilkinson, C. K.

    1988-01-01

    In 1985, two non-attitude-controlled satellites were each placed in a low earth orbit by the Scout Launch Vehicle. The satellites were cylindrical in shape and contained reservoirs of hydrazine fuel. Three-axis magnetometer measurements, telemetered in real time, were used to derive the attitude motion of each satellite. Algorithms are generated to deduce possible orientations (and magnitudes) of each vehicle's angular momentum for each telemetry contact. To resolve ambiguities at each contact, a force model was derived to simulate the significant long-term effects of magnetic, gravity gradient, and aerodynamic torques on the angular momentum of the vehicles. The histories of the orientation and magnitude of the angular momentum are illustrated.

  1. A comparison of drive mechanisms for precision motion controlled stages

    SciTech Connect

    Buice, E S; Yang, H; Otten, D; Smith, S T; Hocken, R J; Trumper, D L; Seugling, R M

    2006-03-22

    This abstract presents a comparison of two drive mechanisms, a Rohlix{reg_sign} drive and a polymer nut drive, for precision motion controlled stages. A single-axis long-range stage with a 50 mm traverse combined with a short-range stage with a 16 {micro}m traverse at a operational bandwidth of 2.2 kHz were developed to evaluate the performance of the drives. The polymer nut and Rohlix{reg_sign} drives showed 4 nm RMS and 7 nm RMS positioning capabilities respectively, with traverses of 5 mm at a maximum velocity of 0.15 mm{sup -}s{sup -1} with the short range stage operating at a 2.2 kHz bandwidth. Further results will be presented in the subsequent sections.

  2. Persistent Cellular Motion Control and Trapping Using Mechanotactic Signaling

    PubMed Central

    Zhu, Xiaoying; Bouffanais, Roland; Yue, Dick K. P.

    2014-01-01

    Chemotactic signaling and the associated directed cell migration have been extensively studied owing to their importance in emergent processes of cellular aggregation. In contrast, mechanotactic signaling has been relatively overlooked despite its potential for unique ways to artificially signal cells with the aim to effectively gain control over their motile behavior. The possibility of mimicking cellular mechanotactic signals offers a fascinating novel strategy to achieve targeted cell delivery for in vitro tissue growth if proven to be effective with mammalian cells. Using (i) optimal level of extracellular calcium ([Ca2+ ]ext mM) we found, (ii) controllable fluid shear stress of low magnitude (), and (iii) the ability to swiftly reverse flow direction (within one second), we are able to successfully signal Dictyostelium discoideum amoebae and trigger migratory responses with heretofore unreported control and precision. Specifically, we are able to systematically determine the mechanical input signal required to achieve any predetermined sequences of steps including straightforward motion, reversal and trapping. The mechanotactic cellular trapping is achieved for the first time and is associated with a stalling frequency of Hz for a reversing direction mechanostimulus, above which the cells are effectively trapped while maintaining a high level of directional sensing. The value of this frequency is very close to the stalling frequency recently reported for chemotactic cell trapping [Meier B, et al. (2011) Proc Natl Acad Sci USA 108:11417–11422], suggesting that the limiting factor may be the slowness of the internal chemically-based motility apparatus. PMID:25207940

  3. Obstacle avoidance and motion control for mobile robots

    NASA Astrophysics Data System (ADS)

    El-Konyaly, El-Sayed H.; Enab, Yehia M.; Abdel-Kareem, El-Sayed M.

    1995-01-01

    Autonomous mobile robot is an intelligent machine that is capable of navigating in an obstacle- cluttered environment without collision and without human intervention. The robot uses information provided by its sensors to build a map using graph or grid representation. In this paper the environment is spatial and temporally varying. To find a safe path among obstacles, a map must be created and updated each time an obstacle is encountered. We present an algorithmic work based on virtual force field concept for obstacle detection and avoidance. As a result a collision free path between a start point and a goal position through a flat 2D environment is obtained. The obstacle avoidance technique generates a sequence of speed and steering commands for a vehicle with two front wheels separately driven using two dc motors. A new cross coupled computer control scheme for the two drive motors of the vehicle wheels is proposed. The continuous motion of the vehicle is executed using this control scheme. The new control scheme accounts for drives mismatch. Extensive simulation results are conducted to illustrate the useful aspects of the proposed integrated system.

  4. Controlled motion of domain walls in submicron amorphous wires

    SciTech Connect

    Ţibu, Mihai; Lostun, Mihaela; Rotărescu, Cristian; Atiţoaie, Alexandru; Lupu, Nicoleta; Óvári, Tibor-Adrian Chiriac, Horia; Allwood, Dan A.

    2016-05-15

    Results on the control of the domain wall displacement in cylindrical Fe{sub 77.5}Si{sub 7.5}B{sub 15} amorphous glass-coated submicron wires prepared by rapid quenching from the melt are reported. The control methods have relied on conical notches with various depths, up to a few tens of nm, made in the glass coating and in the metallic nucleus using a focused ion beam (FIB) system, and on the use of small nucleation coils at one of the sample ends in order to apply magnetic field pulses aimed to enhance the nucleation of reverse domains. The notch-based method is used for the first time in the case of cylindrical ultrathin wires. The results show that the most efficient technique of controlling the domain wall motion in this type of samples is the simultaneous use of notches and nucleation coils. Their effect depends on wire diameter, notch depth, its position on the wire length, and characteristics of the applied pulse.

  5. Two-Step System Identification and Primitive-Based Motion Planning for Control of Small Unmanned Aerial Vehicles

    NASA Astrophysics Data System (ADS)

    Grymin, David J.

    This dissertation addresses motion planning, modeling, and feedback control for autonomous vehicle systems. A hierarchical approach for motion planning and control of nonlinear systems operating in obstacle environments is presented. To reduce computation time during the motion planning process, dynamically feasible trajectories are generated in real-time through concatenation of pre-specified motion primitives. The motion planning task is posed as a search over a directed graph, and the applicability of informed graph search techniques is investigated. Specifically, a locally greedy algorithm with effective backtracking ability is developed and compared to weighted A* search. The greedy algorithm shows an advantage with respect to solution cost and computation time when larger motion primitive libraries that do not operate on a regular state lattice are utilized. Linearization of the nonlinear system equations about the motion primitive library results in a hybrid linear time-varying model, and an optimal control algorithm using the l 2-induced norm as the performance measure is applied to ensure that the system tracks the desired trajectory. The ability of the resulting controller to closely track the trajectory obtained from the motion planner, despite various disturbances and uncertainties, is demonstrated through simulation. Additionally, an approach for obtaining dynamically feasible reference trajectories and feedback controllers for a small unmanned aerial vehicle (UAV) based on an aerodynamic model derived from flight tests is presented. The modeling approach utilizes the two step method (TSM) with stepwise multiple regression to determine relevant explanatory terms for the aerodynamic models. Dynamically feasible trajectories are then obtained through the solution of an optimal control problem using pseudospectral optimal control software. Discretetime feedback controllers are then obtained to regulate the vehicle along the desired reference trajectory

  6. Abdominal muscle activation changes if the purpose is to control pelvis motion or thorax motion.

    PubMed

    Vera-Garcia, Francisco J; Moreside, Janice M; McGill, Stuart M

    2011-12-01

    The aim of this study was to compare trunk muscular recruitment and lumbar spine kinematics when motion was constrained to either the thorax or the pelvis. Nine healthy women performed four upright standing planar movements (rotations, anterior-posterior translations, medial-lateral translations, and horizontal circles) while constraining pelvis motion and moving the thorax or moving the pelvis while minimizing thorax motion, and four isometric trunk exercises (conventional curl-up, reverse curl-up, cross curl-up, and reverse cross curl-up). Surface EMG (upper and lower rectus abdominis, lateral and medial aspects of external oblique, internal oblique, and latissimus dorsi) and 3D lumbar displacements were recorded. Pelvis movements produced higher EMG amplitudes of the oblique abdominals than thorax motions in most trials, and larger lumbar displacements in the medial-lateral translations and horizontal circles. Conversely, thorax movements produced larger rotational lumbar displacement than pelvis motions during rotations and higher EMG amplitudes for latissimus dorsi during rotations and anterior-posterior translations and for lower rectus abdominis during the crossed curl-ups. Thus, different neuromuscular compartments appear when the objective changes from pelvis to thorax motion. This would suggest that both movement patterns should be considered when planning spine stabilization programs, to optimize exercises for the movement and muscle activations desired. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Design and motion control of bioinspired humanoid robot head from servo motors toward artificial muscles

    NASA Astrophysics Data System (ADS)

    Almubarak, Yara; Tadesse, Yonas

    2017-04-01

    The potential applications of humanoid robots in social environments, motivates researchers to design, and control biomimetic humanoid robots. Generally, people are more interested to interact with robots that have similar attributes and movements to humans. The head is one of most important part of any social robot. Currently, most humanoid heads use electrical motors, pneumatic actuators, and shape memory alloy (SMA) actuators for actuation. Electrical and pneumatic actuators take most of the space and would cause unsmooth motions. SMAs are expensive to use in humanoids. Recently, in many robotic projects, Twisted and Coiled Polymer (TCP) artificial muscles are used as linear actuators which take up little space compared to the motors. In this paper, we will demonstrate the designing process and motion control of a robotic head with TCP muscles. Servo motors and artificial muscles are used for actuating the head motion, which have been controlled by a cost efficient ARM Cortex-M7 based development board. A complete comparison between the two actuators is presented.

  8. Application of nonlinear adaptive motion washout to transport ground-handling simulation

    NASA Technical Reports Server (NTRS)

    Parrish, R. V.; Martin, D. J., Jr.

    1983-01-01

    The application of a nonlinear coordinated adaptive motion washout to the transport ground-handling environment is documented. Additions to both the aircraft math model and the motion washout system are discussed. The additions to the simulated-aircraft math model provided improved modeling fidelity for braking and reverse-thrust application, and the additions to the motion-base washout system allowed transition from the desired flight parameters to the less restrictive ground parameters of the washout.

  9. Passive Motion Paradigm: An Alternative to Optimal Control

    PubMed Central

    Mohan, Vishwanathan; Morasso, Pietro

    2011-01-01

    In the last years, optimal control theory (OCT) has emerged as the leading approach for investigating neural control of movement and motor cognition for two complementary research lines: behavioral neuroscience and humanoid robotics. In both cases, there are general problems that need to be addressed, such as the “degrees of freedom (DoFs) problem,” the common core of production, observation, reasoning, and learning of “actions.” OCT, directly derived from engineering design techniques of control systems quantifies task goals as “cost functions” and uses the sophisticated formal tools of optimal control to obtain desired behavior (and predictions). We propose an alternative “softer” approach passive motion paradigm (PMP) that we believe is closer to the biomechanics and cybernetics of action. The basic idea is that actions (overt as well as covert) are the consequences of an internal simulation process that “animates” the body schema with the attractor dynamics of force fields induced by the goal and task-specific constraints. This internal simulation offers the brain a way to dynamically link motor redundancy with task-oriented constraints “at runtime,” hence solving the “DoFs problem” without explicit kinematic inversion and cost function computation. We argue that the function of such computational machinery is not only restricted to shaping motor output during action execution but also to provide the self with information on the feasibility, consequence, understanding and meaning of “potential actions.” In this sense, taking into account recent developments in neuroscience (motor imagery, simulation theory of covert actions, mirror neuron system) and in embodied robotics, PMP offers a novel framework for understanding motor cognition that goes beyond the engineering control paradigm provided by OCT. Therefore, the paper is at the same time a review of the PMP rationale, as a computational theory, and a perspective presentation of

  10. An adaptive recurrent-neural-network motion controller for X-Y table in CNC machine.

    PubMed

    Lin, Faa-Jeng; Shieh, Hsin-Jang; Shieh, Po-Huang; Shen, Po-Hung

    2006-04-01

    In this paper, an adaptive recurrent-neural-network (ARNN) motion control system for a biaxial motion mechanism driven by two field-oriented control permanent magnet synchronous motors (PMSMs) in the computer numerical control (CNC) machine is proposed. In the proposed ARNN control system, a RNN with accurate approximation capability is employed to approximate an unknown dynamic function, and the adaptive learning algorithms that can learn the parameters of the RNN on line are derived using Lyapunov stability theorem. Moreover, a robust controller is proposed to confront the uncertainties including approximation error, optimal parameter vectors, higher-order terms in Taylor series, external disturbances, cross-coupled interference and friction torque of the system. To relax the requirement for the value of lumped uncertainty in the robust controller, an adaptive lumped uncertainty estimation law is investigated. Using the proposed control, the position tracking performance is substantially improved and the robustness to uncertainties including cross-coupled interference and friction torque can be obtained as well. Finally, some experimental results of the tracking of various reference contours demonstrate the validity of the proposed design for practical applications.

  11. The Application of Leap Motion in Astronaut Virtual Training

    NASA Astrophysics Data System (ADS)

    Qingchao, Xie; Jiangang, Chao

    2017-03-01

    With the development of computer vision, virtual reality has been applied in astronaut virtual training. As an advanced optic equipment to track hand, Leap Motion can provide precise and fluid tracking of hands. Leap Motion is suitable to be used as gesture input device in astronaut virtual training. This paper built an astronaut virtual training based Leap Motion, and established the mathematics model of hands occlusion. At last the ability of Leap Motion to handle occlusion was analysed. A virtual assembly simulation platform was developed for astronaut training, and occlusion gesture would influence the recognition process. The experimental result can guide astronaut virtual training.

  12. Space motion sickness: The sensory motor controls and cardiovascular correlation

    NASA Astrophysics Data System (ADS)

    Souvestre, Philippe A.; Blaber, Andrew P.; Landrock, Clinton K.

    Background and PurposeSpace motion sickness (SMS) and related symptoms remain a major limiting factor in Space operations. A recent comprehensive literature review [J.R. Lackner, Z. DiZio, Space motion sickness, Experimental Brain Research 175 (2006) 377-399, doi 10.1007/s00221-006-0697-y] concluded that SMS does not represent a unique diagnostic entity, and there is no adequate predictor of SMS' susceptibility and severity. No countermeasure has been found reliable to prevent or treat SMS symptoms onset. Recent neurophysiological findings on sensory-motor controls monitoring [P.A. Souvestre, C. Landrock, Biomedical-performance monitoring and assessment of astronauts by means of an ocular vestibular monitoring system, Acta Astronautica, 60 (4-7) (2007) 313-321, doi:10.1016/j.actaastro.2006.08.013] and heart-rate variability (HRV) measurements relationship could explain post-flight orthostatic intolerance (PFOI) in astronauts [A.P. Blaber, R.L. Bondar, M.S. Kassam, Heart rate variability and short duration space flight: relationship to post-flight orthostatic intolerance, BMC Physiology 4 (2004) 6]. These two methodologies are generally overlooked in SMS' analysis. In this paper we present the case for a strong relationship between sensory-motor controls related symptoms, including orthostatic intolerance (OI) and SMS symptoms. MethodsThis paper expands on several previously published papers [J.R. Lackner, Z. DiZio, Space motion sickness, Experimental Brain Research 175 (2006) 377-399, doi 10.1007/s00221-006-0697-y; P.A. Souvestre, C. Landrock, Biomedical-performance monitoring and assessment of astronauts by means of an ocular vestibular monitoring system, Acta Astronautica, 60 (4-7) (2007) 313-321, doi:10.1016/j.actaastro.2006.08.013] along with an updated literature review. An analysis of a 10-year period clinical data from trauma patients experiencing postural deficiency syndrome (PDS) show assessment and monitoring techniques which successfully identify trauma

  13. Measurements and simulation of controlled beamfront motion in the Laser Controlled Collective Accelerator

    SciTech Connect

    Yao, R.L.; Destler, W.W.; Striffler, C.D.; Rodgers, J.; Scgalov, Z.

    1989-01-01

    In the Laser Controlled Collective Accelerator, an intense electron beam is injected at a current above the vacuum space charge limit into an initially evacuated drift tube. A plasma channel, produced by time-sequenced, multiple laser beam ionization of a solid target on the drift tube wall, provides the necessary neutralization to allow for effective beam propagation. By controlling the rate of production of the plasma channel as a function of time down the drift tube, control of the electron beamfront can be achieved. Recent experimental measurements of controlled beamfront motion in this configuration are presented, along with results of ion acceleration experiments conducted using two different accelerating gradients. These results are compared with numerical simulations of the system in which both controlled beamfront motion and ion acceleration is observed consistent with both design expectations and experimental results. 5 refs., 6 figs.

  14. 77 FR 53880 - Portland General Electric Company; Notice of Application Accepted for Filing, Soliciting Motions...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-04

    ...: Amendment of License. b. Project No: 2195-079. c. Date Filed: August 3, 2012. d. Applicant: Portland General... (P-2195-079) on any motions, protests, or comments filed. k. Description of Application: The licensee...

  15. 75 FR 34725 - Preliminary Permit Application Accepted for Filing and Soliciting Comments, Motions To Intervene...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-18

    ..., Motions To Intervene, and Competing Applications; Mahoning Hydropower, LLC June 10, 2010. On May 25, 2010, Mahoning Hydropower, LLC filed an application, pursuant to section 4(f) of the Federal Power Act,...

  16. Complex motion of a vehicle through a series of signals controlled by power-law phase

    NASA Astrophysics Data System (ADS)

    Nagatani, Takashi

    2017-07-01

    We study the dynamic motion of a vehicle moving through the series of traffic signals controlled by the position-dependent phase of power law. All signals are controlled by both cycle time and position-dependent phase. The dynamic model of the vehicular motion is described in terms of the nonlinear map. The vehicular motion varies in a complex manner by varying cycle time for various values of the power of the position-dependent phase. The vehicle displays the periodic motion with a long cycle for the integer power of the phase, while the vehicular motion exhibits the very complex behavior for the non-integer power of the phase.

  17. Effects of Motion Cues on the Training of Multi-Axis Manual Control Skills

    NASA Technical Reports Server (NTRS)

    Zaal, Peter M. T.; Mobertz, Xander R. I.

    2017-01-01

    The study described in this paper investigated the effects of two different hexapod motion configurations on the training and transfer of training of a simultaneous roll and pitch control task. Pilots were divided between two groups which trained either under a baseline hexapod motion condition, with motion typically provided by current training simulators, or an optimized hexapod motion condition, with increased fidelity of the motion cues most relevant for the task. All pilots transferred to the same full-motion condition, representing motion experienced in flight. A cybernetic approach was used that gave insights into the development of pilots use of visual and motion cues over the course of training and after transfer. Based on the current results, neither of the hexapod motion conditions can unambiguously be chosen as providing the best motion for training and transfer of training of the used multi-axis control task. However, the optimized hexapod motion condition did allow pilots to generate less visual lead, control with higher gains, and have better disturbance-rejection performance at the end of the training session compared to the baseline hexapod motion condition. Significant adaptations in control behavior still occurred in the transfer phase under the full-motion condition for both groups. Pilots behaved less linearly compared to previous single-axis control-task experiments; however, this did not result in smaller motion or learning effects. Motion and learning effects were more pronounced in pitch compared to roll. Finally, valuable lessons were learned that allow us to improve the adopted approach for future transfer-of-training studies.

  18. Applications of structure-from-motion photogrammetry to fluvial geomorphology

    NASA Astrophysics Data System (ADS)

    Dietrich, James Thomas

    Since 2011, Structure-from-Motion Multi-View Stereo Photogrammetry (SfM or SfM-MVS) has gone from an overlooked computer vision technique to an emerging methodology for collecting low-cost, high spatial resolution three-dimensional data for topographic or surface modeling in many academic fields. This dissertation examines the applications of SfM to the field of fluvial geomorphology. My research objectives for this dissertation were to determine the error and uncertainty that are inherent in SfM datasets, the use of SfM to map and monitor geomorphic change in a small river restoration project, and the use of SfM to map and extract data to examine multi-scale geomorphic patterns for 32 kilometers of the Middle Fork John Day River. SfM provides extremely consistent results, although there are systematic errors that result from certain survey patterns that need to be accounted for in future applications. Monitoring change on small restoration stream channels with SfM gave a more complete spatial perspective than traditional cross sections on small-scale geomorphic change. Helicopter-based SfM was an excellent platform for low-cost, large scale fluvial remote sensing, and the data extracted from the imagery provided multi-scalar perspectives of downstream patterns of channel morphology. This dissertation makes many recommendations for better and more efficient SfM surveys at all of the spatial scales surveyed. By implementing the improvements laid out here and by other authors, SfM will be a powerful tool that will make 3D data collection more accessible to the wider geomorphic community.

  19. Stimulation of PPC Affects the Mapping between Motion and Force Signals for Stiffness Perception But Not Motion Control.

    PubMed

    Leib, Raz; Mawase, Firas; Karniel, Amir; Donchin, Opher; Rothwell, John; Nisky, Ilana; Davare, Marco

    2016-10-12

    How motion and sensory inputs are combined to assess an object's stiffness is still unknown. Here, we provide evidence for the existence of a stiffness estimator in the human posterior parietal cortex (PPC). We showed previously that delaying force feedback with respect to motion when interacting with an object caused participants to underestimate its stiffness. We found that applying theta-burst transcranial magnetic stimulation (TMS) over the PPC, but not the dorsal premotor cortex, enhances this effect without affecting movement control. We explain this enhancement as an additional lag in force signals. This is the first causal evidence that the PPC is not only involved in motion control, but also has an important role in perception that is disassociated from action. We provide a computational model suggesting that the PPC integrates position and force signals for perception of stiffness and that TMS alters the synchronization between the two signals causing lasting consequences on perceptual behavior.

  20. 14 CFR 25.779 - Motion and effect of cockpit controls.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Personnel and Cargo.... Controls Motion and effect Aileron Right (clockwise) for right wing down. Elevator Rearward for nose...

  1. Switched control of vehicle suspension based on motion-mode detection

    NASA Astrophysics Data System (ADS)

    Du, Haiping; Zhang, Nong; Wang, Lifu

    2014-01-01

    This paper presents a study on switched control of vehicle suspension based on motion-mode detection. This control strategy can be potentially implemented via the interconnected suspension such as hydraulically interconnected suspension by actively switching its interconnection configuration in terms of the dominant vehicle body motion-mode. The design of the switched control law is developed focusing on three vehicle body motion-modes: bounce, pitch, and roll. At first, an H∞ optimal controller will be designed for each motion-mode with the use of a common quadratic Lyapunov function, which guarantees the stability of the switched system under arbitrary switching functions. Then, a motion-mode detection method based on the calculation of the motion-mode energy is introduced. And then, the possible implementation of the control system in practice is discussed. Finally, numerical simulations are used to validate the proposed study.

  2. An intelligent control scheme for precise tip-motion control in atomic force microscopy.

    PubMed

    Wang, Yanyan; Hu, Xiaodong; Xu, Linyan

    2016-01-01

    The paper proposes a new intelligent control method to precisely control the tip motion of the atomic force microscopy (AFM). The tip moves up and down at a high rate along the z direction during scanning, requiring the utilization of a rapid feedback controller. The standard proportional-integral (PI) feedback controller is commonly used in commercial AFMs to enable topography measurements. The controller's response performance is determined by the set of the proportional (P) parameter and the integral (I) parameter. However, the two parameters cannot be automatically altered simultaneously according to the scanning speed and the surface topography during continuors scanning, leading to an inaccurate measurement. Thus a new intelligent controller combining the fuzzy controller and the PI controller is put forward in the paper. The new controller automatically selects the most appropriate PI parameters to achieve a fast response rate on basis of the tracking errors. In the experimental setup, the new controller is realized with a digital signal process (DSP) system, implemented in a conventional AFM system. Experiments are carried out by comparing the new method with the standard PI controller. The results demonstrate that the new method is more robust and effective for the precise tip motion control, corresponding to the achievement of a highly qualified image by shortening the response time of the controller.

  3. Analysis of achievable disturbance attenuation in a precision magnetically-suspended motion control system

    NASA Technical Reports Server (NTRS)

    Kuzin, Alexander V.; Holmes, Michael L.; Behrouzjou, Roxana; Trumper, David L.

    1994-01-01

    The results of the analysis of the achievable disturbance attenuation to get an Angstrom motion control resolution and macroscopic travel in a precision magnetically-suspended motion control system are presented in this paper. Noise sources in the transducers, electronics, and mechanical vibrations are used to develop the control design.

  4. 14 CFR 25.779 - Motion and effect of cockpit controls.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    .... Rudder Right pedal forward for nose right. (2) Secondary. Controls Motion and effect Flaps (or auxiliary lift devices) Forward for flaps up; rearward for flaps down. Trim tabs (or equivalent) Rotate to... and auxiliary controls: (1) Powerplant. Controls Motion and effect Power or thrust Forward to increase...

  5. 14 CFR 25.779 - Motion and effect of cockpit controls.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... Rudder Right pedal forward for nose right. (2) Secondary. Controls Motion and effect Flaps (or auxiliary lift devices) Forward for flaps up; rearward for flaps down. Trim tabs (or equivalent) Rotate to... and auxiliary controls: (1) Powerplant. Controls Motion and effect Power or thrust Forward to increase...

  6. 14 CFR 25.779 - Motion and effect of cockpit controls.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    .... Rudder Right pedal forward for nose right. (2) Secondary. Controls Motion and effect Flaps (or auxiliary lift devices) Forward for flaps up; rearward for flaps down. Trim tabs (or equivalent) Rotate to... and auxiliary controls: (1) Powerplant. Controls Motion and effect Power or thrust Forward to increase...

  7. 14 CFR 25.779 - Motion and effect of cockpit controls.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    .... Rudder Right pedal forward for nose right. (2) Secondary. Controls Motion and effect Flaps (or auxiliary lift devices) Forward for flaps up; rearward for flaps down. Trim tabs (or equivalent) Rotate to... and auxiliary controls: (1) Powerplant. Controls Motion and effect Power or thrust Forward to increase...

  8. Contrast gain control in first- and second-order motion perception.

    PubMed

    Lu, Z L; Sperling, G

    1996-12-01

    A novel pedestal-plus-test paradigm is used to determine the nonlinear gain-control properties of the first-order (luminance) and the second-order (texture-contrast) motion systems, that is, how these systems' responses to motion stimuli are reduced by pedestals and other masking stimuli. Motion-direction thresholds were measured for test stimuli consisting of drifting luminance and texture-contrast-modulation stimuli superimposed on pedestals of various amplitudes. (A pedestal is a static sine-wave grating of the same type and same spatial frequency as the moving test grating.) It was found that first-order motion-direction thresholds are unaffected by small pedestals, but at pedestal contrasts above 1-2% (5-10 x pedestal threshold), motion thresholds increase proportionally to pedestal amplitude (a Weber law). For first-order stimuli, pedestal masking is specific to the spatial frequency of the test. On the other hand, motion-direction thresholds for texture-contrast stimuli are independent of pedestal amplitude (no gain control whatever) throughout the accessible pedestal amplitude range (from 0 to 40%). However, when baseline carrier contrast increases (with constant pedestal modulation amplitude), motion thresholds increase, showing that gain control in second-order motion is determined not by the modulator (as in first-order motion) but by the carrier. Note that baseline contrast of the carrier is inherently independent of spatial frequency of the modulator. The drastically different gain-control properties of the two motion systems and prior observations of motion masking and motion saturation are all encompassed in a functional theory. The stimulus inputs to both first- and second-order motion process are normalized by feedforward, shunting gain control. The different properties arise because the modulator is used to control the first-order gain and the carrier is used to control the second-order gain.

  9. Representation of planar motion of complex joints by means of rolling pairs. Application to neck motion.

    PubMed

    Page, Alvaro; de Rosario, Helios; Gálvez, José A; Mata, Vicente

    2011-02-24

    We propose to model planar movements between two human segments by means of rolling-without-slipping kinematic pairs. We compute the path traced by the instantaneous center of rotation (ICR) as seen from the proximal and distal segments, thus obtaining the fixed and moving centrodes, respectively. The joint motion is then represented by the rolling-without-slipping of one centrode on the other. The resulting joint kinematic model is based on the real movement and accounts for nonfixed axes of rotation; therefore it could improve current models based on revolute pairs in those cases where joint movement implies displacement of the ICR. Previous authors have used the ICR to characterize human joint motion, but they only considered the fixed centrode. Such an approach is not adequate for reproducing motion because the fixed centrode by itself does not convey information about body position. The combination of the fixed and moving centrodes gathers the kinematic information needed to reproduce the position and velocities of moving bodies. To illustrate our method, we applied it to the flexion-extension movement of the head relative to the thorax. The model provides a good estimation of motion both for position variables (mean R(pos)=0.995) and for velocities (mean R(vel)=0.958). This approach is more realistic than other models of neck motion based on revolute pairs, such as the dual-pivot model. The geometry of the centrodes can provide some information about the nature of the movement. For instance, the ascending and descending curves of the fixed centrode suggest a sequential movement of the cervical vertebrae. Copyright © 2010 Elsevier Ltd. All rights reserved.

  10. Photonic equation of motion with application to the Lamb shift

    SciTech Connect

    Ritchie, A B

    2006-12-21

    A photonic equation of motion is proposed which is the scalar product of four-vectors and therefore a Lorentz invariant. A photonic equation of motion, which has not been heretofore established in quantum electrodynamics (QED), would capture the quantum nature of light but yet not have the standard field-operator form, thereby making practical calculations easier to perform. The equation of motion proposed here is applied to the Lamb shift. No divergences exist, and the result agrees with the observed Lamb shift for the 1S{sub 1/2} state of hydrogen within experimental error.

  11. Application of Structure-from-Motion photogrammetry in laboratory flumes

    NASA Astrophysics Data System (ADS)

    Morgan, Jacob A.; Brogan, Daniel J.; Nelson, Peter A.

    2017-01-01

    Structure-from-Motion (SfM) photogrammetry has become widely used for topographic data collection in field and laboratory studies. However, the relative performance of SfM against other methods of topographic measurement in a laboratory flume environment has not been systematically evaluated, and there is a general lack of guidelines for SfM application in flume settings. As the use of SfM in laboratory flume settings becomes more widespread, it is increasingly critical to develop an understanding of how to acquire and process SfM data for a given flume size and sediment characteristics. In this study, we: (1) compare the resolution and accuracy of SfM topographic measurements to terrestrial laser scanning (TLS) measurements in laboratory flumes of varying physical dimensions containing sediments of varying grain sizes; (2) explore the effects of different image acquisition protocols and data processing methods on the resolution and accuracy of topographic data derived from SfM techniques; and (3) provide general guidance for image acquisition and processing for SfM applications in laboratory flumes. To investigate the effects of flume size, sediment size, and photo overlap on the density and accuracy of SfM data, we collected topographic data using both TLS and SfM in five flumes with widths ranging from 0.22 to 6.71 m, lengths ranging from 9.14 to 30.48 m, and median sediment sizes ranging from 0.2 to 31 mm. Acquisition time, image overlap, point density, elevation data, and computed roughness parameters were compared to evaluate the performance of SfM against TLS. We also collected images of a pan of gravel where we varied the distance and angle between the camera and sediment in order to explore how photo acquisition affects the ability to capture grain-scale microtopographic features in SfM-derived point clouds. A variety of image combinations and SfM software package settings were also investigated to determine optimal processing techniques. Results from this

  12. Projection of controlled repeatable real-time moving targets to test and evaluate motion imagery quality

    NASA Astrophysics Data System (ADS)

    Scopatz, Stephen D.; Mendez, Michael; Trent, Randall

    2015-05-01

    The projection of controlled moving targets is key to the quantitative testing of video capture and post processing for Motion Imagery. This presentation will discuss several implementations of target projectors with moving targets or apparent moving targets creating motion to be captured by the camera under test. The targets presented are broadband (UV-VIS-IR) and move in a predictable, repeatable and programmable way; several short videos will be included in the presentation. Among the technical approaches will be targets that move independently in the camera's field of view, as well targets that change size and shape. The development of a rotating IR and VIS 4 bar target projector with programmable rotational velocity and acceleration control for testing hyperspectral cameras is discussed. A related issue for motion imagery is evaluated by simulating a blinding flash which is an impulse of broadband photons in fewer than 2 milliseconds to assess the camera's reaction to a large, fast change in signal. A traditional approach of gimbal mounting the camera in combination with the moving target projector is discussed as an alternative to high priced flight simulators. Based on the use of the moving target projector several standard tests are proposed to provide a corresponding test to MTF (resolution), SNR and minimum detectable signal at velocity. Several unique metrics are suggested for Motion Imagery including Maximum Velocity Resolved (the measure of the greatest velocity that is accurately tracked by the camera system) and Missing Object Tolerance (measurement of tracking ability when target is obscured in the images). These metrics are applicable to UV-VIS-IR wavelengths and can be used to assist in camera and algorithm development as well as comparing various systems by presenting the exact scenes to the cameras in a repeatable way.

  13. Unsteady aerodynamic modeling for arbitrary motions. [for active control techniques

    NASA Technical Reports Server (NTRS)

    Edwards, J. W.

    1977-01-01

    Results indicating that unsteady aerodynamic loads derived under the assumption of simple harmonic motions executed by airfoil or wing can be extended to arbitrary motions are summarized. The generalized Theodorsen (1953) function referable to loads due to simple harmonic oscillations of a wing section in incompressible flow, the Laplace inversion integral for unsteady aerodynamic loads, calculations of root loci of aeroelastic loads, and analysis of generalized compressible transient airloads are discussed.

  14. Effects of Different Heave Motion Components on Pilot Pitch Control Behavior

    NASA Technical Reports Server (NTRS)

    Zaal, Petrus M. T.; Zavala, Melinda A.

    2016-01-01

    The study described in this paper had two objectives. The first objective was to investigate if a different weighting of heave motion components decomposed at the center of gravity, allowing for a higher fidelity of individual components, would result in pilot manual pitch control behavior and performance closer to that observed with full aircraft motion. The second objective was to investigate if decomposing the heave components at the aircraft's instantaneous center of rotation rather than at the center of gravity could result in additional improvements in heave motion fidelity. Twenty-one general aviation pilots performed a pitch attitude control task in an experiment conducted on the Vertical Motion Simulator at NASA Ames under different hexapod motion conditions. The large motion capability of the Vertical Motion Simulator also allowed for a full aircraft motion condition, which served as a baseline. The controlled dynamics were of a transport category aircraft trimmed close to the stall point. When the ratio of center of gravity pitch heave to center of gravity heave increased in the hexapod motion conditions, pilot manual control behavior and performance became increasingly more similar to what is observed with full aircraft motion. Pilot visual and motion gains significantly increased, while the visual lead time constant decreased. The pilot visual and motion time delays remained approximately constant and decreased, respectively. The neuromuscular damping and frequency both decreased, with their values more similar to what is observed with real aircraft motion when there was an equal weighting of the heave of the center of gravity and heave due to rotations about the center of gravity. In terms of open- loop performance, the disturbance and target crossover frequency increased and decreased, respectively, and their corresponding phase margins remained constant and increased, respectively. The decomposition point of the heave components only had limited

  15. An Open-Access Educational Tool for Teaching Motion Dynamics in Multi-Axis Servomotor Control

    ERIC Educational Resources Information Center

    Rivera-Guillen, J. R.; de Jesus Rangel-Magdaleno, J.; de Jesus Romero-Troncoso, R.; Osornio-Rios, R. A.; Guevara-Gonzalez, R. G.

    2012-01-01

    Servomotors are widely used in computerized numerically controlled (CNC) machines, hence motion control is a major topic covered in undergraduate/graduate engineering courses. Despite the fact that several syllabi include the motion dynamics topic in their courses, there are neither suitable tools available for designing and simulating multi-axis…

  16. An Open-Access Educational Tool for Teaching Motion Dynamics in Multi-Axis Servomotor Control

    ERIC Educational Resources Information Center

    Rivera-Guillen, J. R.; de Jesus Rangel-Magdaleno, J.; de Jesus Romero-Troncoso, R.; Osornio-Rios, R. A.; Guevara-Gonzalez, R. G.

    2012-01-01

    Servomotors are widely used in computerized numerically controlled (CNC) machines, hence motion control is a major topic covered in undergraduate/graduate engineering courses. Despite the fact that several syllabi include the motion dynamics topic in their courses, there are neither suitable tools available for designing and simulating multi-axis…

  17. Center of gravity motions and ankle joint stiffness control in upright undisturbed stance modeled through a fractional Brownian motion framework.

    PubMed

    Rougier, P; Caron, O

    2000-12-01

    The authors modeled the center of gravity vertical projection (CG(v)) and the difference, CP - CG(v), which, combined, constitute the center of pressure (CP) trajectory, as fractional Brownian motion in order to investigate their relative contributions and their spatiotemporal articulation. The results demonstrated that CG(v) and CP - CG(v) motions are both endowed in complementary fashion with strong stochastic and part-deterministic behaviors. In addition, if the temporal coordinates remain similar for all 3 trajectories by definition, the switch between the successive control mechanisms appears for shorter displacements for CP - CG(v) and CG(v) than for CP trajectories. Results deduced from both input (CG(v)) and muscular stiffness (CP - CG(v)) thus provide insight into the way the central nervous system regulates stance control and in particular how CG and CP - CG are controlled.

  18. Adaptive motion artifact reducing algorithm for wrist photoplethysmography application

    NASA Astrophysics Data System (ADS)

    Zhao, Jingwei; Wang, Guijin; Shi, Chenbo

    2016-04-01

    Photoplethysmography (PPG) technology is widely used in wearable heart pulse rate monitoring. It might reveal the potential risks of heart condition and cardiopulmonary function by detecting the cardiac rhythms in physical exercise. However the quality of wrist photoelectric signal is very sensitive to motion artifact since the thicker tissues and the fewer amount of capillaries. Therefore, motion artifact is the major factor that impede the heart rate measurement in the high intensity exercising. One accelerometer and three channels of light with different wavelengths are used in this research to analyze the coupled form of motion artifact. A novel approach is proposed to separate the pulse signal from motion artifact by exploiting their mixing ratio in different optical paths. There are four major steps of our method: preprocessing, motion artifact estimation, adaptive filtering and heart rate calculation. Five healthy young men are participated in the experiment. The speeder in the treadmill is configured as 12km/h, and all subjects would run for 3-10 minutes by swinging the arms naturally. The final result is compared with chest strap. The average of mean square error (MSE) is less than 3 beats per minute (BPM/min). Proposed method performed well in intense physical exercise and shows the great robustness to individuals with different running style and posture.

  19. Clinical applications of a quantitative analysis of regional lift ventricular wall motion

    NASA Technical Reports Server (NTRS)

    Leighton, R. F.; Rich, J. M.; Pollack, M. E.; Altieri, P. I.

    1975-01-01

    Observations were summarized which may have clinical application. These were obtained from a quantitative analysis of wall motion that was used to detect both hypokinesis and tardokinesis in left ventricular cineangiograms. The method was based on statistical comparisons with normal values for regional wall motion derived from the cineangiograms of patients who were found not to have heart disease.

  20. Cooperative motion control for multi-target observation

    SciTech Connect

    Parker, L.E.

    1997-08-01

    An important issue that arises in the automation of many security, surveillance, and reconnaissance tasks is that of monitoring (or observing) the movements of targets navigating in a bounded area of interest. A key research issue in these problems is that of sensor placement--determining where sensors should be located to maintain the targets in view. In complex applications involving limited-range sensors, the use of multiple sensors dynamically moving over time is required. In this paper, the author investigates the use of a cooperative team of autonomous sensor-based robots for the observation of multiple moving targets. The focus is primarily on developing the distributed control strategies that allow the robot team to attempt to minimize the total time in which targets escape observation by some robot team member in the area of interest. This paper first formalizes the problem and discusses related work. The author then presents a distributed approximate approach to solving this problem that combines low-level multi-robot control with higher-level reasoning control based on the ALLIANCE formalism. The effectiveness of the approach is analyzed by comparing it to three other feasible algorithms for cooperative control, showing the superiority of the approach for a large class of problems.

  1. Multi-robot motion control for cooperative observation

    SciTech Connect

    Parker, L.E.

    1997-06-01

    An important issue that arises in the automation of many security, surveillance, and reconnaissance tasks is that of monitoring (or observing) the movements of targets navigating in a bounded area of interest. A key research issue in these problems is that of sensor placement--determining where sensors should be located to maintain the targets in view. In complex applications involving limited-range sensors, the use of multiple sensors dynamically moving over time is required. In this paper, the authors investigate the use of a cooperative team of autonomous sensor-based robots for the observation of multiple moving targets. They focus primarily on developing the distributed control strategies that allow the robot team to attempt to minimize the total time in which targets escape observation by some robot team member in the area of interest. This paper first formalizes the problem and discusses related work. The authors then present a distributed approximate approach to solving this problem that combines low-level multi-robot control with higher-level reasoning control based on the ALLIANCE formalism. They analyze the effectiveness of the approach by comparing it to 3 other feasible algorithms for cooperative control, showing the superiority of the approach for a large class of problems.

  2. Enhanced Modeling of First-Order Plant Equations of Motion for Aeroelastic and Aeroservoelastic Applications

    NASA Technical Reports Server (NTRS)

    Pototzky, Anthony S.

    2010-01-01

    A methodology is described for generating first-order plant equations of motion for aeroelastic and aeroservoelastic applications. The description begins with the process of generating data files representing specialized mode-shapes, such as rigid-body and control surface modes, using both PATRAN and NASTRAN analysis. NASTRAN executes the 146 solution sequence using numerous Direct Matrix Abstraction Program (DMAP) calls to import the mode-shape files and to perform the aeroelastic response analysis. The aeroelastic response analysis calculates and extracts structural frequencies, generalized masses, frequency-dependent generalized aerodynamic force (GAF) coefficients, sensor deflections and load coefficients data as text-formatted data files. The data files are then re-sequenced and re-formatted using a custom written FORTRAN program. The text-formatted data files are stored and coefficients for s-plane equations are fitted to the frequency-dependent GAF coefficients using two Interactions of Structures, Aerodynamics and Controls (ISAC) programs. With tabular files from stored data created by ISAC, MATLAB generates the first-order aeroservoelastic plant equations of motion. These equations include control-surface actuator, turbulence, sensor and load modeling. Altitude varying root-locus plot and PSD plot results for a model of the F-18 aircraft are presented to demonstrate the capability.

  3. Control-structure interaction/mirror motion compensation

    NASA Technical Reports Server (NTRS)

    Mclaren, Mark; Chu, Peter; Price, Xen

    1992-01-01

    Space Systems/Loral (formerly Ford Aerospace, Space Systems Division) has implemented a rigid-body Mirror Motion Compensation (MMC) scheme for the GOES-I/M spacecraft currently being built for NASA and NOAA. This has resulted in a factor of 15 reduction in pointing error due to rigid-body spacecraft motion induced by the periodic black-body calibration maneuvers required for the instruments. For GOES the spacecraft and the payload mirrors are considered as rigid bodies. The structural flexibility effects are small and are included in the total pointing budget as a separate item. This paper extends the MMC technique to include structural flexibility. For large multi-payload platforms, the structural flexibility effects can be more important in sensor pointing jitter as the result of payload motion. Sensitivity results are included to show the importance of the dynamic model fidelity.

  4. Stirling engine power control and motion conversion mechanism

    SciTech Connect

    Marks, David T.

    1983-01-01

    A motion conversion device for converting between the reciprocating motion of the pistons in a Stirling engine and the rotating motion of its output shaft, and for changing the stroke and phase of the pistons, includes a lever pivoted at one end and having a cam follower at the other end. The piston rod engages the lever intermediate its ends and the cam follower engages a cam keyed to the output shaft. The lever pivot can be moved to change the length of the moment arm defined between the cam follower and the piston rod the change the piston stroke and force exerted on the cam, and the levers can be moved in opposite directions to change the phase between pistons.

  5. Pebble-bed pebble motion: Simulation and Applications

    SciTech Connect

    Joshua J. Cogliati; Abderrafi M. Ougouag

    2011-11-01

    Pebble bed reactors (PBR) have moving graphite fuel pebbles. This unique feature provides advantages, but also means that simulation of the reactor requires understanding the typical motion and location of the granular flow of pebbles. This report presents a method for simulation of motion of the pebbles in a PBR. A new mechanical motion simulator, PEBBLES, efficiently simulates the key elements of motion of the pebbles in a PBR. This model simulates gravitational force and contact forces including kinetic and true static friction. It's used for a variety of tasks including simulation of the effect of earthquakes on a PBR, calculation of packing fractions, Dancoff factors, pebble wear and the pebble force on the walls. The simulator includes a new differential static friction model for the varied geometries of PBRs. A new static friction benchmark was devised via analytically solving the mechanics equations to determine the minimum pebble-to-pebble friction and pebble-to-surface friction for a five pebble pyramid. This pyramid check as well as a comparison to the Janssen formula was used to test the new static friction equations. Because larger pebble bed simulations involve hundreds of thousands of pebbles and long periods of time, the PEBBLES code has been parallelized. PEBBLES runs on shared memory architectures and distributed memory architectures. For the shared memory architecture, the code uses a new O(n) lock-less parallel collision detection algorithm to determine which pebbles are likely to be in contact. The new collision detection algorithm improves on the traditional non-parallel O(n log(n)) collision detection algorithm. These features combine to form a fast parallel pebble motion simulation. The PEBBLES code provides new capabilities for understanding and optimizing PBRs. The PEBBLES code has provided the pebble motion data required to calculate the motion of pebbles during a simulated earthquake. The PEBBLES code provides the ability to determine

  6. Control of Respiratory Motion by Hypnosis Intervention during Radiotherapy of Lung Cancer I

    PubMed Central

    Deng, Jie; Xie, Yaoqin

    2013-01-01

    The uncertain position of lung tumor during radiotherapy compromises the treatment effect. To effectively control respiratory motion during radiotherapy of lung cancer without any side effects, a novel control scheme, hypnosis, has been introduced in lung cancer treatment. In order to verify the suggested method, six volunteers were selected with a wide range of distribution of age, weight, and chest circumference. A set of experiments have been conducted for each volunteer, under the guidance of the professional hypnotist. All the experiments were repeated in the same environmental condition. The amplitude of respiration has been recorded under the normal state and hypnosis, respectively. Experimental results show that the respiration motion of volunteers in hypnosis has smaller and more stable amplitudes than in normal state. That implies that the hypnosis intervention can be an alternative way for respiratory control, which can effectively reduce the respiratory amplitude and increase the stability of respiratory cycle. The proposed method will find useful application in image-guided radiotherapy. PMID:24093100

  7. An optimal control strategy for two-dimensional motion camouflage with non-holonimic constraints.

    PubMed

    Rañó, Iñaki

    2012-07-01

    Motion camouflage is a stealth behaviour observed both in hover-flies and in dragonflies. Existing controllers for mimicking motion camouflage generate this behaviour on an empirical basis or without considering the kinematic motion restrictions present in animal trajectories. This study summarises our formal contributions to solve the generation of motion camouflage as a non-linear optimal control problem. The dynamics of the system capture the kinematic restrictions to motion of the agents, while the performance index ensures camouflage trajectories. An extensive set of simulations support the technique, and a novel analysis of the obtained trajectories contributes to our understanding of possible mechanisms to obtain sensor based motion camouflage, for instance, in mobile robots.

  8. Controlling the motion and placement of micrometer-sized metal particles using patterned polymer brush surfaces.

    PubMed

    Dunderdale, Gary J; Howse, Jonathan R; Fairclough, J Patrick A

    2011-10-04

    In this paper, we show that silicon surfaces patterned with poly(methacrylic acid) brushes are able to control the Brownian motion of 2-3 μm iron particles, which sediment onto the surface in aqueous solution and experience differences in repulsive force depending upon their position. Differences in repulsion lead to different gravitational potential energies across the surface, which gives bias to the Brownian motion taking place. Three regimes have been identified depending upon the brush height: (i) no control of Brownian motion when the brush height is small, (ii) Brownian motion that is influenced by the polymer brush when the brush 17 height is intermediate, (iii) Brownian motion that is confined by polymer brush barriers when the brush height is greatest. The height of brush found necessary to significantly influence iron particle motion was small at 39 nm or 2% of the particle diameter.

  9. 75 FR 71103 - Hampshire Paper Company; Notice of Application Accepted for Filing, Soliciting Motions To...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-22

    ... Hampshire Paper Company; Notice of Application Accepted for Filing, Soliciting Motions To Intervene and Protests, Ready for Environmental Analysis, and Soliciting Comments, Recommendations, Preliminary Terms and...: Hampshire Paper Company. e. Name of Project: Emeryville Hydroelectric Project. f. Location: The existing...

  10. Optimal Control of Stochastic Systems Driven by Fractional Brownian Motions

    DTIC Science & Technology

    2014-10-09

    motion, Warsaw, Poland: Banach Center Publications, (12 2014) TOTAL: 2 PERCENT_SUPPORTEDNAME FTE Equivalent: Total Number: Discipline Cody Clifton 0.25...Discipline Collin Eubanks 0.25 Mathematics 0.25 1 NAME Total Number: Cody Clifton Theodore Lindsey 2 NAME Total Number: PERCENT_SUPPORTEDNAME FTE Equivalent

  11. Comparison of Cervical Spine Motion During Application Among 4 Rigid Immobilization Collars

    PubMed Central

    James, Colleen Y.; Munkasy, Barry A.; Joyner, A. Barry

    2004-01-01

    Objective: To quantify the cervical spine range of motion that occurred during application of 4 rigid cervical immobilization collars, the time of application, and the amount of active range of motion available after application. Design and Setting: We evaluated the amount of cervical motion that occurred during application of 4 commonly used collars: NECLOC (NL), StifNeck (SN), StifNeck Select (SNS), and Rapid Form Vacuum Immobilizer (VI). Each clinician applied a properly sized collar to both a small- and medium-size model 3 times. After application, active range-of-motion testing was completed with the subject in the supine and seated positions. Subjects: A total of 17 certified athletic trainers participated. Measurements: We used 3-dimensional kinematic head and thorax data to calculate peak angular displacement, total linear distance, and total angular distance during application and peak angular displacement during supine and seated range-of-motion testing. Application time was calculated during each trial. Results: Significant differences between collars were noted for application time, total linear distance, and total angular distance (P< .01). The SN and SNS were applied significantly faster and with significantly less total linear distance and total angular distance than the NL and the VI collars. The NL was applied significantly faster and with significantly less total linear distance and total angular distance than the VI. During supine and seated active range-of-motion tests, the SN and SNS permitted significantly less cervical flexion-extension, rotation, and lateral flexion than the NL and VI. Conclusions: Of the collars tested, the SN and SNS appear to be the optimal collars for use by certified athletic trainers. They were applied with the least motion in the fastest time and provided superior restriction during active range-of-motion testing. PMID:15173864

  12. A visual motion detecting module for dragonfly-controlled robots.

    PubMed

    Pham, Thuy T; Higgins, Charles M

    2014-01-01

    When imitating biological sensors, we have not completely understood the early processing of the input to reproduce artificially. Building hybrid systems with both artificial and real biological components is a promising solution. For example, when a dragonfly is used as a living sensor, the early processing of visual information is performed fully in the brain of the dragonfly. The only significant remaining tasks are recording and processing neural signals in software and/or hardware. Based on existing works which focused on recording neural signals, this paper proposes a software application of neural information processing to design a visual processing module for dragonfly hybrid bio-robots. After a neural signal is recorded in real-time, the action potentials can be detected and matched with predefined templates to detect when and which descending neurons fire. The output of the proposed system will be used to control other parts of the robot platform.

  13. 78 FR 35015 - Alabama Power Company; Notice of Application Accepted for Filing, Soliciting Comments, Motions to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-11

    ... Energy Regulatory Commission Alabama Power Company; Notice of Application Accepted for Filing, Soliciting Comments, Motions to Intervene, And Protests Take notice that the following hydroelectric application has been filed with the Commission and is available for public inspection: a. Application Type: Non-project...

  14. 77 FR 107 - Notice of Preliminary Permit Application Accepted for Filing and Soliciting Comments, Motions To...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-03

    ... Comments, Motions To Intervene, and Competing Applications; Earth By Design, Inc. On October 13, 2011, and supplemented on October 30, 2011, Earth By Design, Inc. filed an application for a preliminary permit, pursuant... generation of the project would be 7.2 gigawatt-hours. Applicant Contact: Mr. Jim Gordon, President, Earth...

  15. 77 FR 101 - Rumford Falls Hydro, LLC; Notice of Application Accepted for Filing, Soliciting Comments, Motions...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-03

    ..., 1024 Central Street, Millinocket, ME 04462, (207) 723-4341. i. FERC Contact: Mr. Jeremy Jessup, (202) 502-6779, Jeremy.Jessup@ferc.gov . j. Deadline for filing comments, motions to intervene, and protests... boundary because the applicant owned it. l. Locations of the Application: A copy of the application...

  16. Stimulation of PPC Affects the Mapping between Motion and Force Signals for Stiffness Perception But Not Motion Control

    PubMed Central

    Mawase, Firas; Karniel, Amir; Donchin, Opher; Rothwell, John; Nisky, Ilana; Davare, Marco

    2016-01-01

    How motion and sensory inputs are combined to assess an object's stiffness is still unknown. Here, we provide evidence for the existence of a stiffness estimator in the human posterior parietal cortex (PPC). We showed previously that delaying force feedback with respect to motion when interacting with an object caused participants to underestimate its stiffness. We found that applying theta-burst transcranial magnetic stimulation (TMS) over the PPC, but not the dorsal premotor cortex, enhances this effect without affecting movement control. We explain this enhancement as an additional lag in force signals. This is the first causal evidence that the PPC is not only involved in motion control, but also has an important role in perception that is disassociated from action. We provide a computational model suggesting that the PPC integrates position and force signals for perception of stiffness and that TMS alters the synchronization between the two signals causing lasting consequences on perceptual behavior. SIGNIFICANCE STATEMENT When selecting an object such as a ripe fruit or sofa, we need to assess the object's stiffness. Because we lack dedicated stiffness sensors, we rely on an as yet unknown mechanism that generates stiffness percepts by combining position and force signals. Here, we found that the posterior parietal cortex (PPC) contributes to combining position and force signals for stiffness estimation. This finding challenges the classical view about the role of the PPC in regulating position signals only for motion control because we highlight a key role of the PPC in perception that is disassociated from action. Altogether this sheds light on brain mechanisms underlying the interaction between action and perception and may help in the development of better teleoperation systems and rehabilitation of patients with sensory impairments. PMID:27733607

  17. Analytic Theory and Control of the Motion of Spinning Rigid Bodies

    NASA Technical Reports Server (NTRS)

    Tsiotras, Panagiotis

    1993-01-01

    -fixed torques. Assessment of the analytic solutions reveals that they are very accurate; for symmetric bodies the solutions of Euler's equations of motion are, in fact, exact. Second, the results of this research have a fundamental impact on practical scientific and mechanical applications in terms of the analysis and control of all finite-sized rigid bodies ranging from nanomachines to very large bodies, both man made and natural. After all, Euler's equations of motion apply to all physical bodies, barring only the extreme limits of quantum mechanics and relativity.

  18. Analytic Theory and Control of the Motion of Spinning Rigid Bodies

    NASA Technical Reports Server (NTRS)

    Tsiotras, Panagiotis

    1993-01-01

    -fixed torques. Assessment of the analytic solutions reveals that they are very accurate; for symmetric bodies the solutions of Euler's equations of motion are, in fact, exact. Second, the results of this research have a fundamental impact on practical scientific and mechanical applications in terms of the analysis and control of all finite-sized rigid bodies ranging from nanomachines to very large bodies, both man made and natural. After all, Euler's equations of motion apply to all physical bodies, barring only the extreme limits of quantum mechanics and relativity.

  19. Linear motion device and method for inserting and withdrawing control rods

    DOEpatents

    Smith, Jay E.

    1984-01-01

    A linear motion device, more specifically a control rod drive mechanism (CRDM) for inserting and withdrawing control rods into a reactor core, is capable of independently and sequentially positioning two sets of control rods with a single motor stator and rotor. The CRDM disclosed can control more than one control rod lead screw without incurring a substantial increase in the size of the mechanism.

  20. Real-time visual feedback of COM and COP motion properties differentially modifies postural control structures.

    PubMed

    Kilby, Melissa C; Molenaar, Peter C M; Slobounov, Semyon M; Newell, Karl M

    2017-01-01

    The experiment was setup to investigate the control of human quiet standing through the manipulation of augmented visual information feedback of selective properties of the motion of two primary variables in postural control: center of pressure (COP) and center of mass (COM). Five properties of feedback information were contrasted to a no feedback dual-task (watching a movie) control condition to determine the impact of visual real-time feedback on the coordination of the joint motions in postural control in both static and dynamic one-leg standing postures. The feedback information included 2D COP or COM position and macro variables derived from the COP and COM motions, namely virtual time-to-contact (VTC) and the COP-COM coupling. The findings in the static condition showed that the VTC and COP-COM coupling feedback conditions decreased postural motion more than the 2D COP or COM positional information. These variables also induced larger sway amplitudes in the dynamic condition showing a more progressive search strategy in exploring the stability limits. Canonical correlation analysis (CCA) found that COP-COM coupling contributed less than the other feedback variables to the redundancy of the system reflected in the common variance between joint motions and properties of sway motion. The COP-COM coupling had the lowest weighting of the motion properties to redundancy under the feedback conditions but overall the qualitative pattern of the joint motion structures was preserved within the respective static and dynamic balance conditions.

  1. Control of wearable motion assist robot for upper limb based on the equilibrium position estimation.

    PubMed

    Mizutani, Naoto; Yamane, Michi; Kato, Norihiko; Yano, Ken'ichi; Aoki, Takaaki; Nishimoto, Yutaka; Kobayashi, Yasuyuki

    2013-01-01

    In this paper, we propose a robotic system for assisting patients who have upper limb dysfunction in performing reaching movements through flexion. Since upper limb motion is more strongly needed than lower limb mobility for near work, a patient's level of recovery of upper limb function influences daily life. Recently, with the widespread application of robotic technology in rehabilitation medicine, active movement has often been noted to be more important than passive movement for rapid recovery. A novel control method for assisting upper limb movement by using a control system with two degrees of freedom is proposed. In the process of estimating the trajectory, the minimum jerk criterion is used to compute the velocity trajectory and to determine the reach position. The aim is to eventually develop a movement assistance system for the upper limb which will enable wearers to perform flexion and extension covering ranges of motion which are otherwise impossible to achieve autonomously. The effectiveness of the developed system is demonstrated experimentally.

  2. Novel Expressions of Equations of Relative Motion and Control in Keplerian Orbits

    DTIC Science & Technology

    2009-04-01

    spacecraft , and thus prediction and control of relative motion is significantly sensitive to relative orbit modeling errors [9...proposed a continuous feedback controller for rendezvous navigation in elliptical orbit . In this work, the full equations of relative motion (see [9... Rendezvous in Elliptical Orbits ,” Acta Astronautica, Vol. 41, No. 2, July 1997, pp. 95–101. doi:10.1016/S0094-5765(97)00204-X [19] Yu, S., “ Control

  3. Fractional Brownian Motion:. Theory and Application to DNA Walk

    NASA Astrophysics Data System (ADS)

    Lim, S. C.; Muniandy, S. V.

    2001-09-01

    This paper briefly reviews the theory of fractional Brownian motion (FBM) and its generalization to multifractional Brownian motion (MBM). FBM and MBM are applied to a biological system namely the DNA sequence. By considering a DNA sequence as a fractal random walk, it is possible to model the noncoding sequence of human retinoblastoma DNA as a discrete version of FBM. The average scaling exponent or Hurst exponent of the DNA walk is estimated to be H = 0.60 ± 0.05 using the monofractal R/S analysis. This implies that the mean square fluctuation of DNA walk belongs to anomalous superdiffusion type. We also show that the DNA landscape is not monofractal, instead one has multifractal DNA landscape. The empirical estimates of the Hurst exponent falls approximately within the range H ~ 0.62 - 0.72. We propose two multifractal models, namely the MBM and multiscale FBM to describe the existence of different Hurst exponents in DNA walk.

  4. Abstracted Workow Framework with a Structure from Motion Application

    NASA Astrophysics Data System (ADS)

    Rossi, Adam J.

    In scientific and engineering disciplines, from academia to industry, there is an increasing need for the development of custom software to perform experiments, construct systems, and develop products. The natural mindset initially is to shortcut and bypass all overhead and process rigor in order to obtain an immediate result for the problem at hand, with the misconception that the software will simply be thrown away at the end. In a majority of the cases, it turns out the software persists for many years, and likely ends up in production systems for which it was not initially intended. In the current study, a framework that can be used in both industry and academic applications mitigates underlying problems associated with developing scientific and engineering software. This results in software that is much more maintainable, documented, and usable by others, specifically allowing new users to extend capabilities of components already implemented in the framework. There is a multi-disciplinary need in the fields of imaging science, computer science, and software engineering for a unified implementation model, which motivates the development of an abstracted software framework. Structure from motion (SfM) has been identified as one use case where the abstracted workflow framework can improve research efficiencies and eliminate implementation redundancies in scientific fields. The SfM process begins by obtaining 2D images of a scene from different perspectives. Features from the images are extracted and correspondences are established. This provides a sufficient amount of information to initialize the problem for fully automated processing. Transformations are established between views, and 3D points are established via triangulation algorithms. The parameters for the camera models for all views / images are solved through bundle adjustment, establishing a highly consistent point cloud. The initial sparse point cloud and camera matrices are used to generate a dense

  5. Dimensional coordinate measurements: application in characterizing cervical spine motion

    NASA Astrophysics Data System (ADS)

    Zheng, Weilong; Li, Linan; Wang, Shibin; Wang, Zhiyong; Shi, Nianke; Xue, Yuan

    2014-06-01

    Cervical spine as a complicated part in the human body, the form of its movement is diverse. The movements of the segments of vertebrae are three-dimensional, and it is reflected in the changes of the angle between two joint and the displacement in different directions. Under normal conditions, cervical can flex, extend, lateral flex and rotate. For there is no relative motion between measuring marks fixed on one segment of cervical vertebra, the cervical vertebrae with three marked points can be seen as a body. Body's motion in space can be decomposed into translational movement and rotational movement around a base point .This study concerns the calculation of dimensional coordinate of the marked points pasted to the human body's cervical spine by an optical method. Afterward, these measures will allow the calculation of motion parameters for every spine segment. For this study, we choose a three-dimensional measurement method based on binocular stereo vision. The object with marked points is placed in front of the CCD camera. Through each shot, we will get there two parallax images taken from different cameras. According to the principle of binocular vision we can be realized three-dimensional measurements. Cameras are erected parallelly. This paper describes the layout of experimental system and a mathematical model to get the coordinates.

  6. Quantifying and controlling collective motion in externally guided cells

    NASA Astrophysics Data System (ADS)

    Parker, Joshua; Guven, Can; Wang, Chenlu; Ott, Edward; Losert, Wolfgang

    2015-03-01

    Many motile cells use chemical signals to coordinate their motion to aid in performing a larger task, be it healing a wound or aggregating to form a spore. This coordination can vary from subtle variations in overall alignment to broad, visibly structured patterns. Of particular interest of study are two organisms We introduce a model for motion towards a chemical signal and study these spatio-temporal correlations in the context of autocrine relay, such as seen in Dictyostelium discoideum, where we demonstrate that adhesion and chemical degradation both enhance visible ``streaming'' structures. We also study a model of paracrine signal relay relevant to human neutrophil migration and demonstrate how temporally varying chemical signals can be used to coordinate cell migration. We discuss both of these results in the context of their relevance to the survival of the organism and highlight future experimental tests.

  7. Handbook on astronaut crew motion disturbances for control system design. [in skylab

    NASA Technical Reports Server (NTRS)

    Kullas, M. C.

    1979-01-01

    The analyses and results pertinent to the characterization of the disturbances imparted to the Skylab vehicle by the T-013 crew motion experiments are summarized. Guidelines to help control system designers assess anticipated crew motion disturbances during the design cycle of a new manned spacecraft control system are provided. These guidelines, in conjunction with the T-013 characterizations outlined, begin with the control system conceptual design and conclude with preliminary expectations for pointing performance as affected by crew motions. Block diagrams to highlight the contents so that the reader can easily identify the information and data flow are used. These diagrams provide a handy cross reference of related topics.

  8. Quantitative analysis of motion control in long term microgravity.

    PubMed

    Baroni, G; Ferrigno, G; Anolli, A; Andreoni, G; Pedotti, A

    1998-01-01

    In the frame of the 179-days EUROMIR '95 space mission, two in-flight experiments have foreseen quantitative three-dimensional human movement analysis in microgravity. For this aim, a space qualified opto-electronic motion analyser based on passive markers has been installed onboard the Russian Space Station MIR and 8 in flight sessions have been performed. Techhology and method for the collection of kinematics data are described, evaluating the accuracy in three-dimensional marker localisation. Results confirm the suitability of opto-electronic technology for quantitative human motion analysis on orbital modules and raise a set of "lessons learned", leading to the improvement of motion analyser performance with a contemporary swiftness of the on-board operations. Among the experimental program of T4, results of three voluntary posture perturbation protocols are described. The analysis suggests that a short term reinterpretation of proprioceptive information and re-calibration of sensorimotor mechanisms seem to end within the first weeks of flight, while a continuous long term adaptation process allows the refinement of motor performance, in the frame of never abandoned terrestrial strategies.

  9. Applications of markerless motion capture in gait recognition.

    PubMed

    Sandau, Martin

    2016-03-01

    This thesis is based on four manuscripts where two of them were accepted and two were submitted to peer-reviewed journals. The experimental work behind the thesis was conducted at the Institute of Neuroscience and Pharmacology, University of Copenhagen. The purpose of the studies was to explore the variability of human gait and to conduct new methods for precise estimation of the kinematic parameters applied in forensic gait analysis. The gait studies were conducted in a custom built gait laboratory designed to obtain optimal conditions for markerless motion analysis. The set-up consisted of eight synchronised cameras located in the corners of the laboratory, which were connected to a single computer. The captured images were processed with stereovision-based algorithms to provide accurate 3D reconstructions of the participants. The 3D reconstructions of the participants were obtained during normal walking and the kinematics were extracted with manual and automatic methods. The kinematic results from the automatic approach were compared to marker-based motion capture to validate the precision. The results showed that the proposed markerless motion capture method had a precision comparable to marker-based methods in the frontal plane and the sagittal plane. Similar markerless motion capture methods could therefore provide the basis for reliable gait recognition based on kinematic parameters. The manual annotations were compared to the actual anthropometric measurements obtained from MRI scans and the intra- and inter-observer variability was also quantified to observe the associated effect on recognition. The results showed not only that the kinematics in the lower extremities were important but also that the kinematics in the shoulders had a high discriminatory power. Likewise, the shank length was also highly discriminatory, which has not been previously reported. However, it is important that the same expert performs all annotations, as the inter

  10. Brain-machine interfacing control of whole-body humanoid motion

    PubMed Central

    Bouyarmane, Karim; Vaillant, Joris; Sugimoto, Norikazu; Keith, François; Furukawa, Jun-ichiro; Morimoto, Jun

    2014-01-01

    We propose to tackle in this paper the problem of controlling whole-body humanoid robot behavior through non-invasive brain-machine interfacing (BMI), motivated by the perspective of mapping human motor control strategies to human-like mechanical avatar. Our solution is based on the adequate reduction of the controllable dimensionality of a high-DOF humanoid motion in line with the state-of-the-art possibilities of non-invasive BMI technologies, leaving the complement subspace part of the motion to be planned and executed by an autonomous humanoid whole-body motion planning and control framework. The results are shown in full physics-based simulation of a 36-degree-of-freedom humanoid motion controlled by a user through EEG-extracted brain signals generated with motor imagery task. PMID:25140134

  11. Brain-machine interfacing control of whole-body humanoid motion.

    PubMed

    Bouyarmane, Karim; Vaillant, Joris; Sugimoto, Norikazu; Keith, François; Furukawa, Jun-Ichiro; Morimoto, Jun

    2014-01-01

    We propose to tackle in this paper the problem of controlling whole-body humanoid robot behavior through non-invasive brain-machine interfacing (BMI), motivated by the perspective of mapping human motor control strategies to human-like mechanical avatar. Our solution is based on the adequate reduction of the controllable dimensionality of a high-DOF humanoid motion in line with the state-of-the-art possibilities of non-invasive BMI technologies, leaving the complement subspace part of the motion to be planned and executed by an autonomous humanoid whole-body motion planning and control framework. The results are shown in full physics-based simulation of a 36-degree-of-freedom humanoid motion controlled by a user through EEG-extracted brain signals generated with motor imagery task.

  12. Yolk/Shell Colloidal Crystals Incorporating Movable Cores with Their Motion Controlled by an External Electric Field.

    PubMed

    Watanabe, Kanako; Ishii, Haruyuki; Konno, Mikio; Imhof, Arnout; van Blaaderen, Alfons; Nagao, Daisuke

    2017-01-10

    Yolk/shell particles composed of a submicrometer-sized movable core and a silica shell are promising building blocks for novel optical colloidal crystals, because the locations of cores in the shell compartment can be reversibly changed by using external stimuli. Two dimensional arrays of yolk/shell particles incorporating movable cores were prepared by a self-assembly method. The movable cores of colloidal crystals in water could be observed with an optical microscope under application of external electric field. The motions of inner silica cores depended on the electric field strength and frequency and were categorized into three cases: (1) Random Brownian motion, (2) anisotropic motion of cores moving in a direction orthogonal to a field, and (3) suppressed motion fixed in the center of shell compartment. Random Brownian motion of cores was scarcely affected by field strength when a high frequency (in the MHz range) electric field was applied. On the other hand, an increase in field strength at low-frequency fields (kHz) transiently changed the core motion from (1) to (2) and a further increase in field strength changed it from (2) to (3). When the silica core was incorporated in a large void a stronger electric field was needed to suppress its motion than when it was in a small void. The high responsivity to electric fields in a low-frequency range indicated the importance of electric double layer (EDL) interaction between core and inner shell in controlling the core location in yolk/shell colloidal crystals. It was also shown that movable titania cores in yolk/shell particles required a low-frequency field with a high strength to change from the random to anisotropic motion. The result suggested that the electrostatic interaction between EDLs of the silica core and the inner silica wall could be stronger than that between EDLs of the titania core and the silica shell.

  13. A Geometric Approach to Decouple Robotino Motions and its Functional Controllability

    NASA Astrophysics Data System (ADS)

    Straßberger, Daniel; Mercorelli, Paolo; Sergiyenko, Oleg

    2015-11-01

    This paper analyses a functional control of the Robotino. The proposed control strategy considers a functional decoupling control strategy realized using a geometric approach and the invertibility property of the DC-drives with which the Robotino is equipped. For a given control structure the functional controllability is proven for motion trajectories of class C3, continuous functions with third derivative also being continuous. Horizontal, Vertical and Angular motions are considered and the decoupling between these motions is obtained. Control simulation results using real data of the Robotino are shown. The used control which enables to produce the presented results is a standard Linear Model Predictive Control (LMPC), even though for sake of brevity the standard algorithm is not shown.

  14. Application of Analytic Solution in Relative Motion to Spacecraft Formation Flying in Elliptic Orbit

    NASA Astrophysics Data System (ADS)

    Cho, Hancheol; Park, Sang-Young; Choi, Kyu-Hong

    2008-09-01

    The current paper presents application of a new analytic solution in general relative motion to spacecraft formation flying in an elliptic orbit. The calculus of variations is used to analytically find optimal trajectories and controls for the given problem. The inverse of the fundamental matrix associated with the dynamic equations is not required for the solution in the current study. It is verified that the optimal thrust vector is a function of the fundamental matrix of the given state equations. The cost function and the state vector during the reconfiguration can be analytically obtained as well. The results predict the form of optimal solutions in advance without having to solve the problem. Numerical simulation shows the brevity and the accuracy of the general analytic solutions developed in the current paper.

  15. An improved sliding mode control method for omnidirectional mobile robots based on motion characteristics

    NASA Astrophysics Data System (ADS)

    Leng, Chuntao; Cao, Qixin; Lo, Charles

    2010-01-01

    An improved sliding mode control (SMC) method for omni-directional mobile robots (OMRs) is proposed in this paper. Due to the motion characteristics of OMRs, the driving torque acting on each axis while the robot moves in different directions is distinct. Accordingly, a novel concept of anisotropy characteristics for OMRs is proposed here. In order to achieve a coordinated motion in a multi-axis system such as an OMR, the anisotropy characteristics are introduced into SMC system to coordinate the driving torque. The improved motion control method can guarantee that each driving wheel will reach the target speed with proper driving torque. Owing to the advantage of SMC, the control system of OMRs is insensitive to parametric vibration and external disturbances. To validate the performance of the improved motion control method, experiments have been carried out.

  16. An improved sliding mode control method for omnidirectional mobile robots based on motion characteristics

    NASA Astrophysics Data System (ADS)

    Leng, Chuntao; Cao, Qixin; Lo, Charles

    2009-12-01

    An improved sliding mode control (SMC) method for omni-directional mobile robots (OMRs) is proposed in this paper. Due to the motion characteristics of OMRs, the driving torque acting on each axis while the robot moves in different directions is distinct. Accordingly, a novel concept of anisotropy characteristics for OMRs is proposed here. In order to achieve a coordinated motion in a multi-axis system such as an OMR, the anisotropy characteristics are introduced into SMC system to coordinate the driving torque. The improved motion control method can guarantee that each driving wheel will reach the target speed with proper driving torque. Owing to the advantage of SMC, the control system of OMRs is insensitive to parametric vibration and external disturbances. To validate the performance of the improved motion control method, experiments have been carried out.

  17. Optimization of motion control laws for tether crawler or elevator systems

    NASA Technical Reports Server (NTRS)

    Swenson, Frank R.; Von Tiesenhausen, Georg

    1988-01-01

    Based on the proposal of a motion control law by Lorenzini (1987), a method is developed for optimizing motion control laws for tether crawler or elevator systems in terms of the performance measures of travel time, the smoothness of acceleration and deceleration, and the maximum values of velocity and acceleration. The Lorenzini motion control law, based on powers of the hyperbolic tangent function, is modified by the addition of a constant-velocity section, and this modified function is then optimized by parameter selections to minimize the peak acceleration value for a selected travel time or to minimize travel time for the selected peak values of velocity and acceleration. It is shown that the addition of a constant-velocity segment permits further optimization of the motion control law performance.

  18. DIESEL NOX CONTROL APPLICATION

    EPA Science Inventory

    The paper gives results of a project to design, develop, and demonstrate a diesel engine nitrogen oxide (NOx) and particulate matter (PM) control package that will meet the U.S. Navy's emission control requirements. (NOTE: In 1994, EPA issued a Notice for Proposed Rule Making (NP...

  19. DIESEL NOX CONTROL APPLICATION

    EPA Science Inventory

    The paper gives results of a project to design, develop, and demonstrate a diesel engine nitrogen oxide (NOx) and particulate matter (PM) control package that will meet the U.S. Navy's emission control requirements. (NOTE: In 1994, EPA issued a Notice for Proposed Rule Making (NP...

  20. Motion Control of Drift-Free, Left-Invariant Systems on Lie Groups

    DTIC Science & Technology

    1995-09-01

    Prescribed by ANSI Std Z39-18 Motion Control of Drift-Free, Left-Invariant Systems on Lie Groups Naomi Ehrich Leonardy Department of Mechanical ...SI R INSTITUTE FOR SYSTEMS RESEARCH Sponsored by the National Science Foundation Engineering Research Center Program, the University of Maryland...Harvard University, and Industry TECHNICAL RESEARCH REPORT Motion Control of Drift-Free, Left-Invariant Systems on Lie Groups by N.E. Leonard, P.S

  1. Application of interactive motion charts for displaying liver transplantation data in public websites.

    PubMed

    Santori, G

    2014-09-01

    In the past several years a vast amount of digital information has become available in every field of science, and ideas to apply improved strategies for obtaining a more in-depth knowledge of the data are considered in many areas. Although several American and European organizations show regularly in their public websites the aggregated results of organ donation and transplantation, no tools are provided to engage with the final users and to enable them to handle these data. In this study, a new model of Web-based interactive motion charts was applied to aggregated liver transplantation data obtained from a consecutive 28-year series of liver transplantation performed in a single Italian center. The interactive charts were obtained by combining the Google visualization application programming interface and the googleVis package within the open source statistical environment R. The interactive charts may be embedded into online/offline Web pages and rendered in each common browser. The users may interact with the charts by selecting chart type (bubble, bar, or line chart), x- and y-axis scales (linear or logarithmic), variables, bubble size, color, and even changing opacity of unselected items. Moreover, the charts may dynamically display the trend over time of each continuous/categoric variable, allowing users both to trace how the lines changes over time and to control the animation speed. The interactive motion charts should be used in the public websites that manage aggregated data concerning organ donation and transplantation.

  2. Coordinating robot motion, sensing, and control in plans. LDRD project final report

    SciTech Connect

    Xavier, P.G.; Brown, R.G.; Watterberg, P.A.

    1997-08-01

    The goal of this project was to develop a framework for robotic planning and execution that provides a continuum of adaptability with respect to model incompleteness, model error, and sensing error. For example, dividing robot motion into gross-motion planning, fine-motion planning, and sensor-augmented control had yielded productive research and solutions to individual problems. Unfortunately, these techniques could only be combined by hand with ad hoc methods and were restricted to systems where all kinematics are completely modeled in planning. The original intent was to develop methods for understanding and autonomously synthesizing plans that coordinate motion, sensing, and control. The project considered this problem from several perspectives. Results included (1) theoretical methods to combine and extend gross-motion and fine-motion planning; (2) preliminary work in flexible-object manipulation and an implementable algorithm for planning shortest paths through obstacles for the free-end of an anchored cable; (3) development and implementation of a fast swept-body distance algorithm; and (4) integration of Sandia`s C-Space Toolkit geometry engine and SANDROS motion planer and improvements, which yielded a system practical for everyday motion planning, with path-segment planning at interactive speeds. Results (3) and (4) have either led to follow-on work or are being used in current projects, and they believe that (2) will eventually be also.

  3. Dynamics and motion control of a chain of particles on a rough surface

    NASA Astrophysics Data System (ADS)

    Behn, C.; Schale, F.; Zeidis, I.; Zimmermann, K.; Bolotnik, N.

    2017-05-01

    In this paper the mechanics and control of the motion of a straight chain of three particles interconnected with kinematical constraints are investigated. The ground contact is described by dry (discontinuous) or viscous (continuous) friction. Here, we understand this model as a methodological basis for the design of worm-like locomotion systems, i.e., non-pedal mobile robots. This kind of robots will prove an efficient form of locomotion in application to inspection of pipes or for rescue missions. In this paper, a number of issues related to the dynamics and control of artificial limbless locomotion systems are discussed. Simplest models of a limbless locomotor are two-body or three-body systems that move along a horizontal straight line. In the first part of the paper, the controls are assumed in the form of periodic functions with zero average, shifted on a phase one concerning each other. Thus, there is a traveling wave along the chain of particles. In the second part, actuator models are discussed. It is supposed that there are unknown actuator data or the worm system parameter are not known or exactly as well. The focus is on adaptive control algorithms for the worm-like locomotion systems in order to track given reference trajectories, like kinematic gaits. Finally, a prototype together with its signal processing and control software is presented. Theoretically (analytically and numerically) calculated results of the dynamical behavior of the mobile system are compared to experimental data.

  4. Biologically-inspired Devices for Controlling the Motion of Flux-Quanta

    NASA Astrophysics Data System (ADS)

    Nori, Franco

    2002-03-01

    Motor proteins employ non-equilibrium fluctuations in anisotropic media to transport cargo at the cellular level. Similarly, biologically-inspired devices could transport quanta at the nano-scale. We [1,2,3] have studied non-equilibrium thermal fluctuations in several new type of ratchet systems in superconductors with either (a) channel wall asymmetries, (b) graduated pinning density, (c) anisotropic pinning traps. We study stochastic transport of flux quanta in superconductors by alternating current (AC) rectification. Our simulated systems provide a variety of fluxon pumps, "lenses", or fluxon "rectifiers" because in them the applied electrical AC is transformed into a net DC motion of fluxons. Thermal fluctuations and the asymmetry of the potential (e.g., via channel walls, or inhomegeneous pinning distribution) induce this "diode" effect. The latter can have important applications in devices, like SQUID magnetometers, and for "fluxon optics", including convex and concave "fluxon lenses" that focus/concentrate or disperse flux quanta. Certain features are unique to these novel types of two-dimensional (2D) pumps, and different from the previously studied ratchets (mostly in 1D, with only one particle moving). [1] J. Wambaugh, et. al., Superconducting fluxon pumps and lenses. Phys. Rev. Lett. 83, 5106 (1999). [2] C. Olson, et al., Collective interaction-driven ratchet for transporting flux quanta. Phys. Rev. Lett. 87, 7002 (2001). [3] B.Y. Zhu et al., Biologically-inspired Devices for Controlling the Motion of Flux-Quanta, preprint.

  5. MOTION SENSORS IN MULTIPLE SCLEROSIS: NARRATIVE REVIEW AND UPDATE OF APPLICATIONS.

    PubMed

    Sasaki, Jeffer Eidi; Sandroff, Brian; Bamman, Marcas; Motl, Robert W

    2017-09-28

    The use of motion sensors for measuring physical activity in multiple sclerosis (MS) has evolved with increasing research particularly during the past decade. Areas covered: This manuscript reviews the literature regarding the application of motion sensors for measuring physical activity in MS. We first describe 'what is known' about their use in MS by examining the evidence generated between 1997 and 2012, including the psychometric properties of motion sensors in MS and the development of MS-specific accelerometer cut-points. We then evaluate 'what is new' based on research conducted between 2013 and 2017. This includes newer research on psychometric properties of motion sensors in MS, development of new MS-specific accelerometer and step-rate cut-points, sedentary behavior assessment, and research on fitness trackers and multisensors in MS. The final part presents a picture of "what is next" for the applications of motion sensors in MS, especially pertaining new opportunities for testing and using fitness trackers in MS, and tracking disease and disability progression based on motion sensor output. Expert commentary: The use of motion sensors in MS has grown substantially over the years; however, a lot more can be done to explore the full potential and utility of these devices in MS.

  6. Development of a motion-controlled in vitro elbow testing system.

    PubMed

    Dunning, Cynthia E; Gordon, Karen D; King, Graham J W; Johnson, James A

    2003-05-01

    Joint simulators can be used to study motion pathways of a human joint, to investigate changes in joint stability following injury, and to formulate improved reconstructive and rehabilitative procedures. Our objectives were: to develop a laboratory-based, motion-controlled elbow testing apparatus capable of simulating tendon (muscle) loading and displacement in a cadaveric specimen; to describe its performance while testing stable and unstable elbows; and to compare its operation to that of a previously designed load-controlled device. Velocity control of a pneumatic actuator was achieved using a custom-written, closed-loop feedback controller. This actuator was incorporated into an elbow testing system that used additional pneumatic actuators and a combination of motion- and load-control to achieve desired motions. Simulations achieved with this apparatus demonstrated small magnitudes of error in actuator position and highly repeatable flexion pathways with the specimens positioned in vertical, varus, and valgus orientations. The repeatability in motion pathways generated in both a stable and unstable elbow model was equivalent to or better than for similar tests performed using the load-controlled system, and the velocity of the resulting elbow motion was more reproducible.

  7. The 3D Human Motion Control Through Refined Video Gesture Annotation

    NASA Astrophysics Data System (ADS)

    Jin, Yohan; Suk, Myunghoon; Prabhakaran, B.

    In the beginning of computer and video game industry, simple game controllers consisting of buttons and joysticks were employed, but recently game consoles are replacing joystick buttons with novel interfaces such as the remote controllers with motion sensing technology on the Nintendo Wii [1] Especially video-based human computer interaction (HCI) technique has been applied to games, and the representative game is 'Eyetoy' on the Sony PlayStation 2. Video-based HCI technique has great benefit to release players from the intractable game controller. Moreover, in order to communicate between humans and computers, video-based HCI is very crucial since it is intuitive, easy to get, and inexpensive. On the one hand, extracting semantic low-level features from video human motion data is still a major challenge. The level of accuracy is really dependent on each subject's characteristic and environmental noises. Of late, people have been using 3D motion-capture data for visualizing real human motions in 3D space (e.g, 'Tiger Woods' in EA Sports, 'Angelina Jolie' in Bear-Wolf movie) and analyzing motions for specific performance (e.g, 'golf swing' and 'walking'). 3D motion-capture system ('VICON') generates a matrix for each motion clip. Here, a column is corresponding to a human's sub-body part and row represents time frames of data capture. Thus, we can extract sub-body part's motion only by selecting specific columns. Different from low-level feature values of video human motion, 3D human motion-capture data matrix are not pixel values, but is closer to human level of semantics.

  8. The 3D Human Motion Control Through Refined Video Gesture Annotation

    NASA Astrophysics Data System (ADS)

    Jin, Yohan; Suk, Myunghoon; Prabhakaran, B.

    In the beginning of computer and video game industry, simple game controllers consisting of buttons and joysticks were employed, but recently game consoles are replacing joystick buttons with novel interfaces such as the remote controllers with motion sensing technology on the Nintendo Wii [1] Especially video-based human computer interaction (HCI) technique has been applied to games, and the representative game is 'Eyetoy' on the Sony PlayStation 2. Video-based HCI technique has great benefit to release players from the intractable game controller. Moreover, in order to communicate between humans and computers, video-based HCI is very crucial since it is intuitive, easy to get, and inexpensive. On the one hand, extracting semantic low-level features from video human motion data is still a major challenge. The level of accuracy is really dependent on each subject's characteristic and environmental noises. Of late, people have been using 3D motion-capture data for visualizing real human motions in 3D space (e.g, 'Tiger Woods' in EA Sports, 'Angelina Jolie' in Bear-Wolf movie) and analyzing motions for specific performance (e.g, 'golf swing' and 'walking'). 3D motion-capture system ('VICON') generates a matrix for each motion clip. Here, a column is corresponding to a human's sub-body part and row represents time frames of data capture. Thus, we can extract sub-body part's motion only by selecting specific columns. Different from low-level feature values of video human motion, 3D human motion-capture data matrix are not pixel values, but is closer to human level of semantics.

  9. Satellite Relative Motion Control for MIT’s SPHERES Program

    DTIC Science & Technology

    2012-03-01

    Controller . . 52 3.2.2 Optimal Weighting for LQR . . . . . . . . . . . 56 3.2.3 Optimal Weighting for τ . . . . . . . . . . . . . 66 3.2.4 Quaternion...Position, Velocity, and Quaternion Controllers . . . 52 3.4. Translational Controller without Nonlinearities . . . . . . . . . 53 3.5. Nyquist Plot of LQR ...Rate of Lyapunov Function . . . . . . . . . . . . . . . . . 32 Q LQR State Weight Matrix . . . . . . . . . . . . . . . . . . 36 R LQR Control Weight

  10. Controlling aliased dynamics in motion systems? An identification for sampled-data control approach

    NASA Astrophysics Data System (ADS)

    Oomen, Tom

    2014-07-01

    Sampled-data control systems occasionally exhibit aliased resonance phenomena within the control bandwidth. The aim of this paper is to investigate the aspect of these aliased dynamics with application to a high performance industrial nano-positioning machine. This necessitates a full sampled-data control design approach, since these aliased dynamics endanger both the at-sample performance and the intersample behaviour. The proposed framework comprises both system identification and sampled-data control. In particular, the sampled-data control objective necessitates models that encompass the intersample behaviour, i.e., ideally continuous time models. Application of the proposed approach on an industrial wafer stage system provides a thorough insight and new control design guidelines for controlling aliased dynamics.

  11. Geometric Properties of a Mechanical Forward Motion Compensation System Controlled by a Piezoelectric Drive

    NASA Astrophysics Data System (ADS)

    Collette, F.; Gline, S.; Losseau, J.; Lecharlier, L.

    2012-07-01

    Forward Motion Compensation (FMC) systems have been designed to ensure the radiometric quality of motion acquisition in airborne cameras. If the radiometric benefits of FMC have been acknowledged, what are its effects on the geometrical properties of the camera? This paper demonstrates that FMC significantly improves geometrical properties of a camera. Aspects of FMC theory are discussed, with a focus on the near-lossless implementation of this technology into digital aerial camera systems. Among mechanical FMC technologies, the piezoelectric drive is proving to excel in dynamic positioning in both accuracy and repeatability. The patented piezoelectric drive integrated into Optech aerial camera systems allows for continuous and precise sensor motion to ensure exact compensation of the aircraft's forward motion. This paper presents findings that demonstrate the validity of this assertion. The paper also discusses the physical principles involved in motion acquisition. Equations are included that define the motion effect at image level and illustrate how FMC acts to prevent motion effects. The residual motion effect or compensation error is formulated and a practical computation applied to the more restrictive camera case. The assessment concludes that, in the range of airborne camera utilization, the mechanical FMC technique is free of "visible" error at both human eye and computer assessment level. Lastly, the paper proceeds to a detailed technical discussion of piezoelectric drives and why they have proven to be so effective as nanopositioning devices for optical applications. The effectiveness of the patented piezoelectric drives used to achieve FMC in Optech cameras is conclusively demonstrated.

  12. 78 FR 79427 - Greenwood County; Notice of Application Accepted for Filing and Soliciting Comments, Motions To...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-30

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Greenwood County; Notice of Application Accepted for Filing and Soliciting Comments, Motions To Intervene, and Protests Take notice that the following hydroelectric application has been filed with the Commission and...

  13. 78 FR 30297 - Alabama Power Company; Notice of Application Accepted for Filing and Soliciting Comments, Motions...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-22

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Alabama Power Company; Notice of Application Accepted for Filing and Soliciting Comments, Motions To Intervene, and Protests Take notice that the following hydroelectric application has been filed with the Commission...

  14. 76 FR 57731 - Notice of Preliminary Permit Application Accepted for Filing and Soliciting Comments, Motions To...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-16

    ... Comments, Motions To Intervene, and Competing Applications; Kachess Dam Hydropower, LLC On May 31, 2011, Kachess Dam Hydropower, LLC filed an application for a preliminary permit, pursuant to section 4(f) of the... Contact: Carl Spetzler, Kachess Dam Hydropower, LLC, 745 Emerson Street, Palto Alto, CA 94301, phone...

  15. 78 FR 75553 - Cedar Rapids Water Board; Notice of Application Accepted for Filing, Soliciting Comments, Motions...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-12

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Cedar Rapids Water Board; Notice of Application Accepted for Filing, Soliciting Comments, Motions To Intervene, and Protests Take notice that the following hydroelectric application has been filed with the Commission...

  16. Application and API for Real-time Visualization of Ground-motions and Tsunami

    NASA Astrophysics Data System (ADS)

    Aoi, S.; Kunugi, T.; Suzuki, W.; Kubo, T.; Nakamura, H.; Azuma, H.; Fujiwara, H.

    2015-12-01

    Due to the recent progress of seismograph and communication environment, real-time and continuous ground-motion observation becomes technically and economically feasible. K-NET and KiK-net, which are nationwide strong motion networks operated by NIED, cover all Japan by about 1750 stations in total. More than half of the stations transmit the ground-motion indexes and/or waveform data in every second. Traditionally, strong-motion data were recorded by event-triggering based instruments with non-continues telephone line which is connected only after an earthquake. Though the data from such networks mainly contribute to preparations for future earthquakes, huge amount of real-time data from dense network are expected to directly contribute to the mitigation of ongoing earthquake disasters through, e.g., automatic shutdown plants and helping decision-making for initial response. By generating the distribution map of these indexes and uploading them to the website, we implemented the real-time ground motion monitoring system, Kyoshin (strong-motion in Japanese) monitor. This web service (www.kyoshin.bosai.go.jp) started in 2008 and anyone can grasp the current ground motions of Japan. Though this service provides only ground-motion map in GIF format, to take full advantage of real-time strong-motion data to mitigate the ongoing disasters, digital data are important. We have developed a WebAPI to provide real-time data and related information such as ground motions (5 km-mesh) and arrival times estimated from EEW (earthquake early warning). All response data from this WebAPI are in JSON format and are easy to parse. We also developed Kyoshin monitor application for smartphone, 'Kmoni view' using the API. In this application, ground motions estimated from EEW are overlapped on the map with the observed one-second-interval indexes. The application can playback previous earthquakes for demonstration or disaster drill. In mobile environment, data traffic and battery are

  17. Motion Imagery and Robotics Application (MIRA): Standards-Based Robotics

    NASA Technical Reports Server (NTRS)

    Martinez, Lindolfo; Rich, Thomas; Lucord, Steven; Diegelman, Thomas; Mireles, James; Gonzalez, Pete

    2012-01-01

    This technology development originated from the need to assess the debris threat resulting from soil material erosion induced by landing spacecraft rocket plume impingement on extraterrestrial planetary surfaces. The impact of soil debris was observed to be highly detrimental during NASA s Apollo lunar missions and will pose a threat for any future landings on the Moon, Mars, and other exploration targets. The innovation developed under this program provides a simulation tool that combines modeling of the diverse disciplines of rocket plume impingement gas dynamics, granular soil material liberation, and soil debris particle kinetics into one unified simulation system. The Unified Flow Solver (UFS) developed by CFDRC enabled the efficient, seamless simulation of mixed continuum and rarefied rocket plume flow utilizing a novel direct numerical simulation technique of the Boltzmann gas dynamics equation. The characteristics of the soil granular material response and modeling of the erosion and liberation processes were enabled through novel first principle-based granular mechanics models developed by the University of Florida specifically for the highly irregularly shaped and cohesive lunar regolith material. These tools were integrated into a unique simulation system that accounts for all relevant physics aspects: (1) Modeling of spacecraft rocket plume impingement flow under lunar vacuum environment resulting in a mixed continuum and rarefied flow; (2) Modeling of lunar soil characteristics to capture soil-specific effects of particle size and shape composition, soil layer cohesion and granular flow physics; and (3) Accurate tracking of soil-borne debris particles beginning with aerodynamically driven motion inside the plume to purely ballistic motion in lunar far field conditions.

  18. Autogenic-feedback training exercise is superior to promethazine for control of motion sickness symptoms

    NASA Technical Reports Server (NTRS)

    Cowings, P. S.; Toscano, W. B.

    2000-01-01

    Motion sickness symptoms affect approximately 50% of the crew during space travel and are commonly treated with intramuscular injections of promethazine. The purpose of this paper is to compare the effectiveness of three treatments for motion sickness: intramuscular injections (i.m.) of promethazine, a physiological training method (autogenic-feedback training exercise [AFTE]), and a no-treatment control. An earlier study tested the effects of promethazine on cognitive and psychomotor performance and motion sickness tolerance in a rotating chair. For the present paper, motion sickness tolerance, symptom reports, and physiological responses of these subjects were compared to matched subjects selected from an existing database who received either AFTE or no treatment. Three groups of 11 men, between the ages of 33 and 40 years, were matched on the number of rotations tolerated during their initial rotating-chair motion sickness test. The motion sickness test procedures and the 7-day interval between tests were the same for all subjects. The drug group was tested under four treatment conditions: baseline (no injections), a 25 mg dose of promethazine, a 50 mg dose of promethazine, and a placebo of sterile saline. AFTE subjects were given four 30-minute AFTE sessions before their second, third, and fourth motion sickness tests (6 hours total). The no-treatment control subjects were only given the four rotating-chair tests. Motion sickness tolerance was significantly increased after 4 hours of AFTE when compared to either 25 mg (p < 0.00003) or 50 mg (p < 0.00001) of promethazine. The control and promethazine groups did not differ. AFTE subjects reported fewer or no symptoms at higher rotational velocities than subjects in the control or promethazine groups. The primary physiological effect of promethazine was an inhibition of skin conductance level. The AFTE group showed significantly less heart rate and skin conductance variability during motion sickness tests

  19. Autogenic-feedback training exercise is superior to promethazine for control of motion sickness symptoms.

    PubMed

    Cowings, P S; Toscano, W B

    2000-10-01

    Motion sickness symptoms affect approximately 50% of the crew during space travel and are commonly treated with intramuscular injections of promethazine. The purpose of this paper is to compare the effectiveness of three treatments for motion sickness: intramuscular injections (i.m.) of promethazine, a physiological training method (autogenic-feedback training exercise [AFTE]), and a no-treatment control. An earlier study tested the effects of promethazine on cognitive and psychomotor performance and motion sickness tolerance in a rotating chair. For the present paper, motion sickness tolerance, symptom reports, and physiological responses of these subjects were compared to matched subjects selected from an existing database who received either AFTE or no treatment. Three groups of 11 men, between the ages of 33 and 40 years, were matched on the number of rotations tolerated during their initial rotating-chair motion sickness test. The motion sickness test procedures and the 7-day interval between tests were the same for all subjects. The drug group was tested under four treatment conditions: baseline (no injections), a 25 mg dose of promethazine, a 50 mg dose of promethazine, and a placebo of sterile saline. AFTE subjects were given four 30-minute AFTE sessions before their second, third, and fourth motion sickness tests (6 hours total). The no-treatment control subjects were only given the four rotating-chair tests. Motion sickness tolerance was significantly increased after 4 hours of AFTE when compared to either 25 mg (p < 0.00003) or 50 mg (p < 0.00001) of promethazine. The control and promethazine groups did not differ. AFTE subjects reported fewer or no symptoms at higher rotational velocities than subjects in the control or promethazine groups. The primary physiological effect of promethazine was an inhibition of skin conductance level. The AFTE group showed significantly less heart rate and skin conductance variability during motion sickness tests

  20. Developments in Human Centered Cueing Algorithms for Control of Flight Simulator Motion Systems

    NASA Technical Reports Server (NTRS)

    Houck, Jacob A.; Telban, Robert J.; Cardullo, Frank M.

    1997-01-01

    The authors conducted further research with cueing algorithms for control of flight simulator motion systems. A variation of the so-called optimal algorithm was formulated using simulated aircraft angular velocity input as a basis. Models of the human vestibular sensation system, i.e. the semicircular canals and otoliths, are incorporated within the algorithm. Comparisons of angular velocity cueing responses showed a significant improvement over a formulation using angular acceleration input. Results also compared favorably with the coordinated adaptive washout algorithm, yielding similar results for angular velocity cues while eliminating false cues and reducing the tilt rate for longitudinal cues. These results were confirmed in piloted tests on the current motion system at NASA-Langley, the Visual Motion Simulator (VMS). Proposed future developments by the authors in cueing algorithms are revealed. The new motion system, the Cockpit Motion Facility (CMF), where the final evaluation of the cueing algorithms will be conducted, is also described.

  1. Robust cascade control for the horizontal motion of a vehicle with single-wheel actuators

    NASA Astrophysics Data System (ADS)

    Moseberg, Jan-Erik; Roppenecker, Günter

    2015-12-01

    The article presents a cascade control for the horizontal motion of a vehicle with single-wheel actuators. The outer control loop for the longitudinal and lateral accelerations and the yaw rate ensures a desired vehicle motion. By a combination of state feedback control and observer-based disturbance feedforward the inner control loop robustly stabilises the rotating and steering motions of the wheels in spite of unknown frictions between tyres and ground. Since the three degrees of freedom of the horizontal motion are affected by eight tyre forces, the vehicle considered is an over-actuated system. Thus additional control objectives can be realised besides the desired motion trajectory as, for example, a maximum in driving safety. The corresponding analytical tyre force allocation also guarantees real-time capability because of its relatively low computational effort. Provided suitable fault detection and isolation are available, the proposed cascade control has the potential of fault-tolerance, because the force allocation is adaptable. Another benefit results from the modular control structure, because it allows a stepwise implementation. Besides, it only requires a small number of measurements for control purposes. These measurements are the rotational speeds and steering angles of the wheels, the longitudinal and lateral acceleration and the yaw rate of the vehicle.

  2. Digital Control of Flight Simulator Motion Base Actuator.

    DTIC Science & Technology

    1984-01-01

    SYNTHESIS 3.1 Basic Considerations As a starting point for digital controller design a proportional plus integral ( PI ) control law of the form - V(s...on closed loop stability arising from digital realization of the PI control law, computational time delay and sampling have to be taken into

  3. The Development of a Computer Controlled Super 8 Motion Picture Projector.

    ERIC Educational Resources Information Center

    Reynolds, Eldon J.

    Instructors in Child Development at the University of Texas at Austin selected sound motion pictures as the most effective medium to simulate the observation of children in nursery laboratories. A computer controlled projector was designed for this purpose. An interface and control unit controls the Super 8 projector from a time-sharing computer…

  4. 14 CFR 23.779 - Motion and effect of cockpit controls.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and... controls must be designed so that they operate in accordance with the following movement and actuation: (a) Aerodynamic controls: Motion and effect (1) Primary controls: Aileron Right (clockwise) for right wing...

  5. Application of vibrotactile feedback of body motion to improve rehabilitation in individuals with imbalance.

    PubMed

    Wall, Conrad

    2010-06-01

    Balance rehabilitation and vestibular or balance prostheses are both emerging fields that have a potential for synergistic interaction. This article reviews vibrotactile prosthetic devices that have been developed to date and ongoing work related to the application of vibrotactile feedback for enhanced postural control. A vibrotactile feedback device developed in the author's laboratory is described. Twelve subjects with vestibular hypofunction were tested on a platform that moved randomly in a plane, while receiving vibrotactile feedback in the anteroposterior direction. The feedback allowed subjects to significantly decrease their anteroposterior body tilt but did not change mediolateral tilt. A tandem walking task performed by subjects with vestibulopathies demonstrated a reduction in their mediolateral sway due to vibrotactile feedback of mediolateral body tilt, after controlling for the effects of task learning. Published findings from 2 additional experiments conducted in the laboratories of collaborating physical therapists are summarized. The Dynamic Gait Index scores in community-dwelling elderly individuals who were prone to falls were significantly improved with the use of mediolateral body tilt feedback. Although more work is needed, these results suggest that vibrotactile tilt feedback of subjects' body motion can be used effectively by physical therapists for balance rehabilitation. A preliminary description of the third-generation device that has been reduced from a vest format to a belt format is described to demonstrate the progressive evolution from research to clinical application.

  6. Stress Drop and Depth Controls on Ground Motion From Induced Earthquakes

    NASA Astrophysics Data System (ADS)

    Baltay, A.; Rubinstein, J. L.; Terra, F. M.; Hanks, T. C.; Herrmann, R. B.

    2015-12-01

    Induced earthquakes in the central United States pose a risk to local populations, but there is not yet agreement on how to portray their hazard. A large source of uncertainty in the hazard arises from ground motion prediction, which depends on the magnitude and distance of the causative earthquake. However, ground motion models for induced earthquakes may be very different than models previously developed for either the eastern or western United States. A key question is whether ground motions from induced earthquakes are similar to those from natural earthquakes, yet there is little history of natural events in the same region with which to compare the induced ground motions. To address these problems, we explore how earthquake source properties, such as stress drop or depth, affect the recorded ground motion of induced earthquakes. Typically, due to stress drop increasing with depth, ground motion prediction equations model shallower events to have smaller ground motions, when considering the same absolute hypocentral distance to the station. Induced earthquakes tend to occur at shallower depths, with respect to natural eastern US earthquakes, and may also exhibit lower stress drops, which begs the question of how these two parameters interact to control ground motion. Can the ground motions of induced earthquakes simply be understood by scaling our known source-ground motion relations to account for the shallow depth or potentially smaller stress drops of these induced earthquakes, or is there an inherently different mechanism in play for these induced earthquakes? We study peak ground-motion velocity (PGV) and acceleration (PGA) from induced earthquakes in Oklahoma and Kansas, recorded by USGS networks at source-station distances of less than 20 km, in order to model the source effects. We compare these records to those in both the NGA-West2 database (primarily from California) as well as NGA-East, which covers the central and eastern United States and Canada

  7. Robust object tracking techniques for vision-based 3D motion analysis applications

    NASA Astrophysics Data System (ADS)

    Knyaz, Vladimir A.; Zheltov, Sergey Y.; Vishnyakov, Boris V.

    2016-04-01

    Automated and accurate spatial motion capturing of an object is necessary for a wide variety of applications including industry and science, virtual reality and movie, medicine and sports. For the most part of applications a reliability and an accuracy of the data obtained as well as convenience for a user are the main characteristics defining the quality of the motion capture system. Among the existing systems for 3D data acquisition, based on different physical principles (accelerometry, magnetometry, time-of-flight, vision-based), optical motion capture systems have a set of advantages such as high speed of acquisition, potential for high accuracy and automation based on advanced image processing algorithms. For vision-based motion capture accurate and robust object features detecting and tracking through the video sequence are the key elements along with a level of automation of capturing process. So for providing high accuracy of obtained spatial data the developed vision-based motion capture system "Mosca" is based on photogrammetric principles of 3D measurements and supports high speed image acquisition in synchronized mode. It includes from 2 to 4 technical vision cameras for capturing video sequences of object motion. The original camera calibration and external orientation procedures provide the basis for high accuracy of 3D measurements. A set of algorithms as for detecting, identifying and tracking of similar targets, so for marker-less object motion capture is developed and tested. The results of algorithms' evaluation show high robustness and high reliability for various motion analysis tasks in technical and biomechanics applications.

  8. Control of tip-to-sample distance in atomic force microscopy: A dual-actuator tip-motion control scheme

    NASA Astrophysics Data System (ADS)

    Jeong, Younkoo; Jayanth, G. R.; Menq, Chia-Hsiang

    2007-09-01

    The control of tip-to-sample distance in atomic force microscopy (AFM) is achieved through controlling the vertical tip position of the AFM cantilever. In the vertical tip-position control, the required z motion is commanded by laser reading of the vertical tip position in real time and might contain high frequency components depending on the lateral scanning rate and topographical variations of the sample. This paper presents a dual-actuator tip-motion control scheme that enables the AFM tip to track abrupt topographical variations. In the dual-actuator scheme, an additional magnetic mode actuator is employed to achieve high bandwidth tip-motion control while the regular z scanner provides the necessary motion range. This added actuator serves to make the entire cantilever bandwidth available for tip positioning, and thus controls the tip-to-sample distance. A fast programmable electronics board was employed to realize the proposed dual-actuator control scheme, in which model cancellation algorithms were implemented to enlarge the bandwidth of the magnetic actuation and to compensate the lightly damped dynamics of the cantilever. Experiments were conducted to illustrate the capabilities of the proposed dual-actuator tip-motion control in terms of response speed and travel range. It was shown that while the bandwidth of the regular z scanner was merely a small fraction of the cantilever's bandwidth, the dual-actuator control scheme led to a tip-motion control system, the bandwidth of which was comparable to that of the cantilever, where the dynamics overdamped, and the motion range comparable to that of the z scanner.

  9. Control of tip-to-sample distance in atomic force microscopy: a dual-actuator tip-motion control scheme.

    PubMed

    Jeong, Younkoo; Jayanth, G R; Menq, Chia-Hsiang

    2007-09-01

    The control of tip-to-sample distance in atomic force microscopy (AFM) is achieved through controlling the vertical tip position of the AFM cantilever. In the vertical tip-position control, the required z motion is commanded by laser reading of the vertical tip position in real time and might contain high frequency components depending on the lateral scanning rate and topographical variations of the sample. This paper presents a dual-actuator tip-motion control scheme that enables the AFM tip to track abrupt topographical variations. In the dual-actuator scheme, an additional magnetic mode actuator is employed to achieve high bandwidth tip-motion control while the regular z scanner provides the necessary motion range. This added actuator serves to make the entire cantilever bandwidth available for tip positioning, and thus controls the tip-to-sample distance. A fast programmable electronics board was employed to realize the proposed dual-actuator control scheme, in which model cancellation algorithms were implemented to enlarge the bandwidth of the magnetic actuation and to compensate the lightly damped dynamics of the cantilever. Experiments were conducted to illustrate the capabilities of the proposed dual-actuator tip-motion control in terms of response speed and travel range. It was shown that while the bandwidth of the regular z scanner was merely a small fraction of the cantilever's bandwidth, the dual-actuator control scheme led to a tip-motion control system, the bandwidth of which was comparable to that of the cantilever, where the dynamics overdamped, and the motion range comparable to that of the z scanner.

  10. Application of the fractional Levy motion to precipitation data

    NASA Astrophysics Data System (ADS)

    Kuzuha, Y.; Tachinami, S.; Gomi, C.

    2012-12-01

    We applied the fractional Lévy motion model to precipitation data, referring to Lavallée (2004) and Lavallée (2008). The data we used were from the Global Preciptiation Climatology Centre (GPCC) monthly precipitation dataset. These data consist of 360 (longitude) × 180 (latitude) × 1336 (monthly, 1901-2012). First, we constructed four datasets: time series of average monthly precipitation of the top (maximum) 1000 precipitation observation stations, top 10, top 100, and top 500. Next, according to Lavallée (2004) and Lavallée (2008), using Fourier transformation, convolution (filtering) and inverse Fourier transformation, we obtained random variables Xt (Lavallée, 2004) from Yt (precipitation). We transformed from Yt to Xt. Finally, we fitted the Lévy law to Xt. As a preliminary result, we present examples of the values of the Lévy law parameters: alpha, beta, gamma, and delta for the "top 100" dataset. Parameters obtained were (1.17, 0.0, 257.6, 0.28; maximum likelihood), (1.10, 0.0, 250.0, -0.99; quantile algorithm), and (1.20, 0.0, 265.1, 0.57; empirical characteristic function algorithm). We used J. P. Nolan's algorithm. The values are quite sensitive to the algorithm that is used. At the Fall meeting, we will present considerations and results obtained using precipitation data other than those of the GPCC. J. P. Nolan, http://academic2.american.edu/~jpnolan/stable/stable.html Lavallée (2004), Stochastic modeling of climatic variability in dendrochronology, GRL, 31, L15202. Lavallée (2008), On the random nature of earthquake sources and ground motions; a unified theory, Advances in Geophysics, 50, chapter 16. Acknowledgement: We thank Dr. D. Lavallee for his comments and suggestions.; An example of results which we obtained. On a log-log plot, PDF of the Lévy law (red line) is more appropriate than the Gaussian law (blue line) in terms of heavy tail or extreme values. This is consistent with Lavallée (2004) and Lavallée (2008) who used slip

  11. Three axis electronic flight motion simulator real time control system design and implementation

    SciTech Connect

    Gao, Zhiyuan; Miao, Zhonghua Wang, Xiaohua; Wang, Xuyong

    2014-12-15

    A three axis electronic flight motion simulator is reported in this paper including the modelling, the controller design as well as the hardware implementation. This flight motion simulator could be used for inertial navigation test and high precision inertial navigation system with good dynamic and static performances. A real time control system is designed, several control system implementation problems were solved including time unification with parallel port interrupt, high speed finding-zero method of rotary inductosyn, zero-crossing management with continuous rotary, etc. Tests were carried out to show the effectiveness of the proposed real time control system.

  12. Motion control system of MAX IV Laboratory soft x-ray beamlines

    SciTech Connect

    Sjöblom, Peter Lindberg, Mirjam Forsberg, Johan Persson, Andreas G. Urpelainen, Samuli Såthe, Conny

    2016-07-27

    At the MAX IV Laboratory, five new soft x-ray beamlines are under development. The first is Species and it will be used to develop and set the standard of the control system, which will be common across the facility. All motion axes at MAX IV will be motorized using stepper motors steered by the IcePAP motion controller and a mixture of absolute and incremental encoders following a predefined coordinate system. The control system software is built in Tango and uses the Python-based Sardana framework. The user controls the entire beamline through a synoptic overview and Sardana is used to run the scans.

  13. Three axis electronic flight motion simulator real time control system design and implementation.

    PubMed

    Gao, Zhiyuan; Miao, Zhonghua; Wang, Xuyong; Wang, Xiaohua

    2014-12-01

    A three axis electronic flight motion simulator is reported in this paper including the modelling, the controller design as well as the hardware implementation. This flight motion simulator could be used for inertial navigation test and high precision inertial navigation system with good dynamic and static performances. A real time control system is designed, several control system implementation problems were solved including time unification with parallel port interrupt, high speed finding-zero method of rotary inductosyn, zero-crossing management with continuous rotary, etc. Tests were carried out to show the effectiveness of the proposed real time control system.

  14. Walking motion generation, synthesis, and control for biped robot by using PGRL, LPI, and fuzzy logic.

    PubMed

    Li, Tzuu-Hseng S; Su, Yu-Te; Lai, Shao-Wei; Hu, Jhen-Jia

    2011-06-01

    This paper proposes the implementation of fuzzy motion control based on reinforcement learning (RL) and Lagrange polynomial interpolation (LPI) for gait synthesis of biped robots. First, the procedure of a walking gait is redefined into three states, and the parameters of this designed walking gait are determined. Then, the machine learning approach applied to adjusting the walking parameters is policy gradient RL (PGRL), which can execute real-time performance and directly modify the policy without calculating the dynamic function. Given a parameterized walking motion designed for biped robots, the PGRL algorithm automatically searches the set of possible parameters and finds the fastest possible walking motion. The reward function mainly considered is first the walking speed, which can be estimated from the vision system. However, the experiment illustrates that there are some stability problems in this kind of learning process. To solve these problems, the desired zero moment point trajectory is added to the reward function. The results show that the robot not only has more stable walking but also increases its walking speed after learning. This is more effective and attractive than manual trial-and-error tuning. LPI, moreover, is employed to transform the existing motions to the motion which has a revised angle determined by the fuzzy motion controller. Then, the biped robot can continuously walk in any desired direction through this fuzzy motion control. Finally, the fuzzy-based gait synthesis control is demonstrated by tasks and point- and line-target tracking. The experiments show the feasibility and effectiveness of gait learning with PGRL and the practicability of the proposed fuzzy motion control scheme.

  15. Do Motion Controllers Make Action Video Games Less Sedentary? A Randomized Experiment

    PubMed Central

    Lyons, Elizabeth J.; Tate, Deborah F.; Ward, Dianne S.; Ribisl, Kurt M.; Bowling, J. Michael; Kalyanaraman, Sriram

    2012-01-01

    Sports- and fitness-themed video games using motion controllers have been found to produce physical activity. It is possible that motion controllers may also enhance energy expenditure when applied to more sedentary games such as action games. Young adults (N = 100) were randomized to play three games using either motion-based or traditional controllers. No main effect was found for controller or game pair (P > .12). An interaction was found such that in one pair, motion control (mean [SD] 0.96 [0.20] kcal · kg−1 · hr−1) produced 0.10 kcal · kg−1 · hr−1 (95% confidence interval 0.03 to 0.17) greater energy expenditure than traditional control (0.86 [0.17] kcal · kg−1 · hr−1, P = .048). All games were sedentary. As currently implemented, motion control is unlikely to produce moderate intensity physical activity in action games. However, some games produce small but significant increases in energy expenditure, which may benefit health by decreasing sedentary behavior. PMID:22028959

  16. Do motion controllers make action video games less sedentary? A randomized experiment.

    PubMed

    Lyons, Elizabeth J; Tate, Deborah F; Ward, Dianne S; Ribisl, Kurt M; Bowling, J Michael; Kalyanaraman, Sriram

    2012-01-01

    Sports- and fitness-themed video games using motion controllers have been found to produce physical activity. It is possible that motion controllers may also enhance energy expenditure when applied to more sedentary games such as action games. Young adults (N = 100) were randomized to play three games using either motion-based or traditional controllers. No main effect was found for controller or game pair (P > .12). An interaction was found such that in one pair, motion control (mean [SD] 0.96 [0.20] kcal · kg(-1) · hr(-1)) produced 0.10 kcal · kg(-1) · hr(-1) (95% confidence interval 0.03 to 0.17) greater energy expenditure than traditional control (0.86 [0.17] kcal · kg(-1) · hr(-1), P = .048). All games were sedentary. As currently implemented, motion control is unlikely to produce moderate intensity physical activity in action games. However, some games produce small but significant increases in energy expenditure, which may benefit health by decreasing sedentary behavior.

  17. Fixed-base and two-body equations of motion for an Annular Momentum Control Device (AMCD)

    NASA Technical Reports Server (NTRS)

    Groom, N. J.

    1978-01-01

    Fixed base and two body equations of motion for an Annular Momentum Control Device (AMCD) are presented. An AMCD consists of a spinning annular rim which is suspended by noncontacting magnetic bearings and powered by a noncontacting linear electromagnetic motor. The fixed base equations are for a rigid AMCD rim suspended by magnetic bearings attached to a rigid fixed base. The two body equations are for a rigid AMCD rim suspended by magnetic bearings attached to a rigid body spacecraft. The fixed base equations are applicable to any potential ground based AMCD application such as energy storage.

  18. Application Of Image Processing To Human Motion Analysis

    NASA Astrophysics Data System (ADS)

    Baca, Arnold

    1989-10-01

    A novel method is presented for the determination of position and orientation of interconnected human body segments relative to a spatial coordinate system. The development of this new method was prompted by the inadequacy of the techniques currently in use for recorded images. In these techniques, markers are fixed to certain points on the skin of the subject. However, due to skin movement relative to the skeleton and various other factors, the configurational coordinates derived from digitized marker positions may be grossly erroneous with disastrous consequences for the subsequent motion analysis. The new method is based on body-segment shape recognition in the video-image domain. During the recording session, the subject carries special, tight-fitting clothing which permits the unambiguous recognition of segmental shapes and boundaries from the recorded video images. The recognition is performed by means of an edge detection algorithm followed by the computation of the positions and orientations relative to the spatial axes system of all segments of the body model. The new method is implemented on an advanced, special high speed graphic system (Impuls, System 2400) based on transputer chips. The parallel processing capability of this system permits the simultaneous computation of the configurational characteristics for all segments visible in the image. After processing one complete image frame, the video digitizer is instructed to automatically proceed to the next frame, thereby enabling the user to automatically evaluate large amounts of successive frames.

  19. Application of genetic algorithm to hexagon-based motion estimation.

    PubMed

    Kung, Chih-Ming; Cheng, Wan-Shu; Jeng, Jyh-Horng

    2014-01-01

    With the improvement of science and technology, the development of the network, and the exploitation of the HDTV, the demands of audio and video become more and more important. Depending on the video coding technology would be the solution for achieving these requirements. Motion estimation, which removes the redundancy in video frames, plays an important role in the video coding. Therefore, many experts devote themselves to the issues. The existing fast algorithms rely on the assumption that the matching error decreases monotonically as the searched point moves closer to the global optimum. However, genetic algorithm is not fundamentally limited to this restriction. The character would help the proposed scheme to search the mean square error closer to the algorithm of full search than those fast algorithms. The aim of this paper is to propose a new technique which focuses on combing the hexagon-based search algorithm, which is faster than diamond search, and genetic algorithm. Experiments are performed to demonstrate the encoding speed and accuracy of hexagon-based search pattern method and proposed method.

  20. Application of Genetic Algorithm to Hexagon-Based Motion Estimation

    PubMed Central

    Cheng, Wan-Shu

    2014-01-01

    With the improvement of science and technology, the development of the network, and the exploitation of the HDTV, the demands of audio and video become more and more important. Depending on the video coding technology would be the solution for achieving these requirements. Motion estimation, which removes the redundancy in video frames, plays an important role in the video coding. Therefore, many experts devote themselves to the issues. The existing fast algorithms rely on the assumption that the matching error decreases monotonically as the searched point moves closer to the global optimum. However, genetic algorithm is not fundamentally limited to this restriction. The character would help the proposed scheme to search the mean square error closer to the algorithm of full search than those fast algorithms. The aim of this paper is to propose a new technique which focuses on combing the hexagon-based search algorithm, which is faster than diamond search, and genetic algorithm. Experiments are performed to demonstrate the encoding speed and accuracy of hexagon-based search pattern method and proposed method. PMID:24592178

  1. Coordinated joint motion control system with position error correction

    DOEpatents

    Danko, George [Reno, NV

    2011-11-22

    Disclosed are an articulated hydraulic machine supporting, control system and control method for same. The articulated hydraulic machine has an end effector for performing useful work. The control system is capable of controlling the end effector for automated movement along a preselected trajectory. The control system has a position error correction system to correct discrepancies between an actual end effector trajectory and a desired end effector trajectory. The correction system can employ one or more absolute position signals provided by one or more acceleration sensors supported by one or more movable machine elements. Good trajectory positioning and repeatability can be obtained. A two-joystick controller system is enabled, which can in some cases facilitate the operator's task and enhance their work quality and productivity.

  2. Motion and force controlled vibration testing. [of aerospace hardware

    NASA Technical Reports Server (NTRS)

    Scharton, Terry D.; Boatman, David J.; Kern, Dennis L.

    1990-01-01

    A technique for controlling both the input acceleration and force in vibration tests is proposed to alleviate the overtesting risks and the problems associated with response limiting in conventional vibration tests of aerospace hardware. Previous research on impedance and force controlled vibration tests is reviewed and a simple equation governing the dual control of acceleration and force is derived. A practical method for implementing the dual control technique in random vibration tests has been demonstrated in JPL's environmental test facility using a conventional digital controller operating in the extremal mode. The dual control technique provides appropriate real-time notching of the input acceleration and a corresponding reduction of the test item response at resonances. Issues concerning the need for force and acceleration phase information, the adequacy of specifying the blocked force, and the derivation of the total force for multipoint supports are discussed.

  3. Coordinated joint motion control system with position error correction

    DOEpatents

    Danko, George L.

    2016-04-05

    Disclosed are an articulated hydraulic machine supporting, control system and control method for same. The articulated hydraulic machine has an end effector for performing useful work. The control system is capable of controlling the end effector for automated movement along a preselected trajectory. The control system has a position error correction system to correct discrepancies between an actual end effector trajectory and a desired end effector trajectory. The correction system can employ one or more absolute position signals provided by one or more acceleration sensors supported by one or more movable machine elements. Good trajectory positioning and repeatability can be obtained. A two joystick controller system is enabled, which can in some cases facilitate the operator's task and enhance their work quality and productivity.

  4. Flight experience with manually controlled unconventional aircraft motions

    NASA Technical Reports Server (NTRS)

    Barfield, A. F.

    1978-01-01

    A modified YF-16 aircraft was used to flight demonstrate decoupled modes under the USAF Fighter Control Configured Vehicle (CCV) Program. The direct force capabilities were used to implement seven manually controlled unconventional modes on the aircraft, allowing flat turns, decoupled normal acceleration control, independent longitudinal and lateral translations, uncoupled elevation and azimuth aiming, and blended direct lift. This paper describes the design, development, and flight testing of these control modes. The need for task-tailored mode authorities, gain-scheduling and selected closed-loop design is discussed.

  5. Modification of Motion Perception and Manual Control Following Short-Durations Spaceflight

    NASA Technical Reports Server (NTRS)

    Wood, S. J.; Vanya, R. D.; Esteves, J. T.; Rupert, A. H.; Clement, G.

    2011-01-01

    Adaptive changes during space flight in how the brain integrates vestibular cues with other sensory information can lead to impaired movement coordination and spatial disorientation following G-transitions. This ESA-NASA study was designed to examine both the physiological basis and operational implications for disorientation and tilt-translation disturbances following short-duration spaceflights. The goals of this study were to (1) examine the effects of stimulus frequency on adaptive changes in motion perception during passive tilt and translation motion, (2) quantify decrements in manual control of tilt motion, and (3) evaluate vibrotactile feedback as a sensorimotor countermeasure.

  6. Human motion planning based on recursive dynamics and optimal control techniques

    NASA Technical Reports Server (NTRS)

    Lo, Janzen; Huang, Gang; Metaxas, Dimitris

    2002-01-01

    This paper presents an efficient optimal control and recursive dynamics-based computer animation system for simulating and controlling the motion of articulated figures. A quasi-Newton nonlinear programming technique (super-linear convergence) is implemented to solve minimum torque-based human motion-planning problems. The explicit analytical gradients needed in the dynamics are derived using a matrix exponential formulation and Lie algebra. Cubic spline functions are used to make the search space for an optimal solution finite. Based on our formulations, our method is well conditioned and robust, in addition to being computationally efficient. To better illustrate the efficiency of our method, we present results of natural looking and physically correct human motions for a variety of human motion tasks involving open and closed loop kinematic chains.

  7. Reduction of vortex induced forces and motion through surface roughness control

    DOEpatents

    Bernitsas, Michael M; Raghavan, Kamaldev

    2014-04-01

    Roughness is added to the surface of a bluff body in a relative motion with respect to a fluid. The amount, size, and distribution of roughness on the body surface is controlled passively or actively to modify the flow around the body and subsequently the Vortex Induced Forces and Motion (VIFM). The added roughness, when designed and implemented appropriately, affects in a predetermined way the boundary layer, the separation of the boundary layer, the level of turbulence, the wake, the drag and lift forces, and consequently the Vortex Induced Motion (VIM), and the fluid-structure interaction. The goal of surface roughness control is to decrease/suppress Vortex Induced Forces and Motion. Suppression is required when fluid-structure interaction becomes destructive as in VIM of flexible cylinders or rigid cylinders on elastic support, such as underwater pipelines, marine risers, tubes in heat exchangers, nuclear fuel rods, cooling towers, SPAR offshore platforms.

  8. Human motion planning based on recursive dynamics and optimal control techniques

    NASA Technical Reports Server (NTRS)

    Lo, Janzen; Huang, Gang; Metaxas, Dimitris

    2002-01-01

    This paper presents an efficient optimal control and recursive dynamics-based computer animation system for simulating and controlling the motion of articulated figures. A quasi-Newton nonlinear programming technique (super-linear convergence) is implemented to solve minimum torque-based human motion-planning problems. The explicit analytical gradients needed in the dynamics are derived using a matrix exponential formulation and Lie algebra. Cubic spline functions are used to make the search space for an optimal solution finite. Based on our formulations, our method is well conditioned and robust, in addition to being computationally efficient. To better illustrate the efficiency of our method, we present results of natural looking and physically correct human motions for a variety of human motion tasks involving open and closed loop kinematic chains.

  9. Linear motion device and method for inserting and withdrawing control rods

    DOEpatents

    Smith, J.E.

    Disclosed is a linear motion device and more specifically a control rod drive mechanism (CRDM) for inserting and withdrawing control rods into a reactor core. The CRDM and method disclosed is capable of independently and sequentially positioning two sets of control rods with a single motor stator and rotor. The CRDM disclosed can control more than one control rod lead screw without incurring a substantial increase in the size of the mechanism.

  10. Prediction and control of limit cycling motions in boosting rockets

    NASA Astrophysics Data System (ADS)

    Newman, Brett

    An investigation concerning the prediction and control of observed limit cycling behavior in a boosting rocket is considered. The suspected source of the nonlinear behavior is the presence of Coulomb friction in the nozzle pivot mechanism. A classical sinusoidal describing function analysis is used to accurately recreate and predict the observed oscillatory characteristic. In so doing, insight is offered into the limit cycling mechanism and confidence is gained in the closed-loop system design. Nonlinear simulation results are further used to support and verify the results obtained from describing function theory. Insight into the limit cycling behavior is, in turn, used to adjust control system parameters in order to passively control the oscillatory tendencies. Tradeoffs with the guidance and control system stability/performance are also noted. Finally, active control of the limit cycling behavior, using a novel feedback algorithm to adjust the inherent nozzle sticking-unsticking characteristics, is considered.

  11. Numerical simulation of motion-induced dynamic noise in a ubiquitous ECG application.

    PubMed

    Kim, Young Tae; Lim, Ki Moo; Hong, Seong Bae; Ryu, Ah Jin; Ko, Byung Hoon; Bae, Sang Kon; Shin, Kun Soo; Shim, Eun Bo

    2011-01-01

    Wearable ubiquitous biomedical applications, such as ECG monitors, can generate dynamic noise as a person moves. However, the source of this noise is not clear. We postulated that the dynamic ECG noise has two causes: the change in displacement of the heart during motion and the change in the electrical impedance of the skin-gel interface due to motion-induced deformation of the skin-gel interface. Using a three-dimensional electrophysiological heart model coupled with a torso model, dynamic noise was simulated, while the displacement of the heart was changed in the vertical and horizontal directions, independently and while the skin-gel interface was deformed during motion. To determine the deformation rate of the skin and sol-gel layers, motion-induced deformation of the two layers was simulated using a three-dimensional finite element method.

  12. An analysis of the treatment couch and control system dynamics for respiration-induced motion compensation

    SciTech Connect

    D'Souza, Warren D.; McAvoy, Thomas J.

    2006-12-15

    Sophisticated methods for real-time motion compensation include using the linear accelerator, MLC, or treatment couch. To design such a couch, the required couch and control system dynamics need to be investigated. We used an existing treatment couch known as the Hexapod{sup TM} to gain insight into couch dynamics and an internal model controller to simulate feedback control of respiration-induced motion. The couch dynamics, described using time constants and dead times, were investigated using step inputs. The resulting data were modeled as first and second order systems with dead time. The couch was determined to have a linear response for step inputs {<=}1 cm. Motion data from 12 patients were obtained using a skin marker placed on the abdomen of the patient and the marker data were assumed to be an exact surrogate of tumor motion. The feedback system was modeled with the couch as a second-ordersystem and the controller as a first order system. The time constants of the couch and controller and the dead times were varied starting with parameters obtained from the Hexapod{sup TM} couch and the performance of the feedback system was evaluated. The resulting residual motion under feedback control was generally <0.3 cm when a fast enough couch was simulated.

  13. Maximum Principle for General Controlled Systems Driven by Fractional Brownian Motions

    SciTech Connect

    Han Yuecai; Hu Yaozhong; Song Jian

    2013-04-15

    We obtain a maximum principle for stochastic control problem of general controlled stochastic differential systems driven by fractional Brownian motions (of Hurst parameter H>1/2). This maximum principle specifies a system of equations that the optimal control must satisfy (necessary condition for the optimal control). This system of equations consists of a backward stochastic differential equation driven by both fractional Brownian motions and the corresponding underlying standard Brownian motions. In addition to this backward equation, the maximum principle also involves the Malliavin derivatives. Our approach is to use conditioning and Malliavin calculus. To arrive at our maximum principle we need to develop some new results of stochastic analysis of the controlled systems driven by fractional Brownian motions via fractional calculus. Our approach of conditioning and Malliavin calculus is also applied to classical system driven by standard Brownian motions while the controller has only partial information. As a straightforward consequence, the classical maximum principle is also deduced in this more natural and simpler way.

  14. Active control of the attitude motion and structural vibration of a flexible satellite by jet thrusters

    NASA Astrophysics Data System (ADS)

    Lee, Mokin

    A Lagrangian formulation is used to obtain the equations of motion of a flexible satellite in a tree-type geometry. The flexible satellite model is the geosynchronous INSAT-II type satellite with a flexible balance beam and a flexible solar panel attached to the rigid main body. In deriving the equations of motion, the orbital motion, the librational motion, and the structural motion of flexible bodies are involved. The assumed-modes method is used to express the deflections of the flexible structures in the form of a finite series of space-dependent admissible functions multiplied by time-dependent amplitudes. The kinetic energy, potential energy, strain energy, and virtual work of the flexible satellite are evaluated as functions of time in terms of the generalized coordinates. Then, by substituting them into Lagrange's equations for discrete systems, the governing equations of motion of the flexible satellite are obtained as a set of second-order nonlinear ordinary differential equations. The attitude motion and the structural motion of the flexible satellite are coupled motions with one another. Uncontrolled dynamics show that the librational and structural motions are oscillatory and undamped motions. The stability and performance of the flexible satellite needs to be improved by designing control systems. A control objective is proposed to improve the stability and performance for pointing accuracy maneuver by controlling the librational motions and flexible modes simultaneously. For the control objective, a control system is synthesized, using feedback linearization control, thrust determination, thrust management, and pulse-width pulse-frequency modulation. Feedback linearization for second-order nonlinear systems is used to obtain a stable feedback control system for the pointing-accuracy control. A stable feedback control system is obtained by adjusting the diagonal matrices of the linear second-order system. Jet thrusters are used as the primary

  15. Extended analytical formulas for the perturbed Keplerian motion under a constant control acceleration

    NASA Astrophysics Data System (ADS)

    Zuiani, Federico; Vasile, Massimiliano

    2015-03-01

    This paper presents a set of analytical formulae for the perturbed Keplerian motion of a spacecraft under the effect of a constant control acceleration. The proposed set of formulae can treat control accelerations that are fixed in either a rotating or inertial reference frame. Moreover, the contribution of the zonal harmonic is included in the analytical formulae. It will be shown that the proposed analytical theory allows for the fast computation of long, multi-revolution spirals while maintaining good accuracy. The combined effect of different perturbations and of the shadow regions due to solar eclipse is also included. Furthermore, a simplified control parameterisation is introduced to optimise thrusting patterns with two thrust arcs and two cost arcs per revolution. This simple parameterisation is shown to ensure enough flexibility to describe complex low thrust spirals. The accuracy and speed of the proposed analytical formulae are compared against a full numerical integration with different integration schemes. An averaging technique is then proposed as an application of the analytical formulae. Finally, the paper presents an example of design of an optimal low-thrust spiral to transfer a spacecraft from an elliptical to a circular orbit around the Earth.

  16. Neural network-based motion control of an underactuated wheeled inverted pendulum model.

    PubMed

    Yang, Chenguang; Li, Zhijun; Cui, Rongxin; Xu, Bugong

    2014-11-01

    In this paper, automatic motion control is investigated for one of wheeled inverted pendulum (WIP) models, which have been widely applied for modeling of a large range of two wheeled modern vehicles. First, the underactuated WIP model is decomposed into a fully actuated second order subsystem Σa consisting of planar movement of vehicle forward and yaw angular motions, and a nonactuated first order subsystem Σb of pendulum motion. Due to the unknown dynamics of subsystem Σa and the universal approximation ability of neural network (NN), an adaptive NN scheme has been employed for motion control of subsystem Σa . The model reference approach has been used whereas the reference model is optimized by the finite time linear quadratic regulation technique. The pendulum motion in the passive subsystem Σb is indirectly controlled using the dynamic coupling with planar forward motion of subsystem Σa , such that satisfactory tracking of a set pendulum tilt angle can be guaranteed. Rigours theoretic analysis has been established, and simulation studies have been performed to demonstrate the developed method.

  17. Nonlinear adaptive motion control for manipulators with compliant joints.

    PubMed

    Yung, J H; Fu, L C

    1998-01-01

    How to perform control and achieve stability of robotic manipulators with joint flexibility forms a problem of profound practical and theoretical interest. This paper is to investigate and to solve this problem without strict assumption on the joint stiffness. Here, an adaptive control scheme of a flexible-joint manipulator, which takes into account its full nonlinear dynamics, is presented. Without the knowledge of the system model, the developed control lams, requiring only the position and velocity information of the actuators and links, is capable of driving the link tracking errors asymptotically to zero, while maintaining the uniform boundedness of all signals in the closed-loop system. To demonstrate the effectiveness of the proposed control law, an example of a two-link flexible-joint manipulator is constructed and a number of computer simulations are performed which show quite satisfactory results.

  18. Optimal control of molecular motion expressed through quantum fluid dynamics

    NASA Astrophysics Data System (ADS)

    Dey, Bijoy K.; Rabitz, Herschel; Askar, Attila

    2000-04-01

    A quantum fluid-dynamic (QFD) control formulation is presented for optimally manipulating atomic and molecular systems. In QFD the control quantum system is expressed in terms of the probability density ρ and the quantum current j. This choice of variables is motivated by the generally expected slowly varying spatial-temporal dependence of the fluid-dynamical variables. The QFD approach is illustrated for manipulation of the ground electronic state dynamics of HCl induced by an external electric field.

  19. The application of biological motion research: biometrics, sport, and the military.

    PubMed

    Steel, Kylie; Ellem, Eathan; Baxter, David

    2015-02-01

    The body of research that examines the perception of biological motion is extensive and explores the factors that are perceived from biological motion and how this information is processed. This research demonstrates that individuals are able to use relative (temporal and spatial) information from a person's movement to recognize factors, including gender, age, deception, emotion, intention, and action. The research also demonstrates that movement presents idiosyncratic properties that allow individual discrimination, thus providing the basis for significant exploration in the domain of biometrics and social signal processing. Medical forensics, safety garments, and victim selection domains also have provided a history of research on the perception of biological motion applications; however, a number of additional domains present opportunities for application that have not been explored in depth. Therefore, the purpose of this paper is to present an overview of the current applications of biological motion-based research and to propose a number of areas where biological motion research, specific to recognition, could be applied in the future.

  20. An Interface for Specifying Rigid-Body Motions for CFD Applications

    NASA Technical Reports Server (NTRS)

    Murman, Scott M.; Chan, William; Aftosmis, Michael; Meakin, Robert L.; Kwak, Dochan (Technical Monitor)

    2003-01-01

    An interface for specifying rigid-body motions for CFD applications is presented. This interface provides a means of describing a component hierarchy in a geometric configuration, as well as the motion (prescribed or six-degree-of-freedom) associated with any component. The interface consists of a general set of datatypes, along with rules for their interaction, and is designed to be flexible in order to evolve as future needs dictate. The specification is currently implemented with an XML file format which is portable across platforms and applications. The motion specification is capable of describing general rigid body motions, and eliminates the need to write and compile new code within the application software for each dynamic configuration, allowing client software to automate dynamic simulations. The interface is integrated with a GUI tool which allows rigid body motions to be prescribed and verified interactively, promoting access to non-expert users. Illustrative examples, as well as the raw XML source of the file specifications, are included.

  1. Controllers, observers, and applications thereof

    NASA Technical Reports Server (NTRS)

    Gao, Zhiqiang (Inventor); Miklosovic, Robert (Inventor); Radke, Aaron (Inventor); Zhou, Wankun (Inventor); Zheng, Qing (Inventor)

    2011-01-01

    Controller scaling and parameterization are described. Techniques that can be improved by employing the scaling and parameterization include, but are not limited to, controller design, tuning and optimization. The scaling and parameterization methods described here apply to transfer function based controllers, including PID controllers. The parameterization methods also apply to state feedback and state observer based controllers, as well as linear active disturbance rejection (ADRC) controllers. Parameterization simplifies the use of ADRC. A discrete extended state observer (DESO) and a generalized extended state observer (GESO) are described. They improve the performance of the ESO and therefore ADRC. A tracking control algorithm is also described that improves the performance of the ADRC controller. A general algorithm is described for applying ADRC to multi-input multi-output systems. Several specific applications of the control systems and processes are disclosed.

  2. Control of airship motion in the presence of wind

    NASA Astrophysics Data System (ADS)

    Nakpiam, Jatuporn

    This research effort develops a guidance and control system for a small airship to fly through assigned waypoints in the three dimensional space with a desired speed in the presence of wind and wind gust. In the control system development and validation, a simulation environment based on the nonlinear 6-DOF model of an airship, including the effect of the wind, is used. The airship has five control variables, the main thrust, the main thrust angle, the tail thrust, elevator and rudder deflections. The effectiveness of the elevator and rudder degrades as the speed of the airship decreases. The controller design is based on MIMO (Multi-Input Multi-Output) LQR (Linear Quadratic Regulator) method. A gain scheduling scheme is used to cover multiple operating conditions based on the forward speed. An extensive nominal condition analysis is performed to understand the variation of the nominal values of the state and control variables with the change in speed. This enabled a better choice of the nominal conditions used in the gain scheduling controller. The simulation experiments show that the airship can fly through the assigned waypoints, even when the waypoints are at different altitudes, when the commanded speed is constant. Alternatively, the way-point navigation can be achieved while commanded speed is changed if the commanded altitude is kept constant. The simulations show that altitude and the speed changes cannot be commanded simultaneously if the changes are large.

  3. How NASA KSC Controls Interfaces with the use of Motion Skeletons and Product Structure

    NASA Technical Reports Server (NTRS)

    Jones, Corey

    2013-01-01

    This presentation will show how NASA KSC controls interfaces for Modular Product Architecture (MPA) using Locator Skeletons, Interface Skeletons, and Product Structure, to be combined together within a Motion Skeleton. The user will learn how to utilize skeleton models to communicate interface data, as successfully done at NASA KSC in their use of Motion Skeletons to control interfaces for multi-launch systems. There will be discussion of the methodology used to control design requirements through WTParts, and how to utilize product structure for non-CAD documents.

  4. On the dynamics and control of the relative motion between two spacecraft

    NASA Astrophysics Data System (ADS)

    Yu, Shaohua

    1995-03-01

    The dynamics of the relative motion between two nearby spacecraft is investigated in a local orbital co-ordinate system. A phase plane analysis shows that a stable equilibrium state may exist in the motion. Based on this analysis, a control method called the range-rate control algorithm (RRCA) has been established. The controlled trajectory is stable and in a straight line. Furthermore, an omni-directional version of RRCA has also been introduced. The computation, measurement and propulsion scheme for the algorithm is very simple. As an illustrated example, the tethered satellite system as well as the in-orbit spacecraft rendezvous are simulated by the algorithm.

  5. Motion of the two-control airplane in rectilinear flight after initial disturbances with introduction of controls following an exponential law

    NASA Technical Reports Server (NTRS)

    Klemin, Alexander

    1937-01-01

    An airplane in steady rectilinear flight was assumed to experience an initial disturbance in rolling or yawing velocity. The equations of motion were solved to see if it was possible to hasten recovery of a stable airplane or to secure recovery of an unstable airplane by the application of a single lateral control following an exponential law. The sample computations indicate that, for initial disturbances complex in character, it would be difficult to secure correlation with any type of exponential control. The possibility is visualized that the two-control operation may seriously impair the ability to hasten recovery or counteract instability.

  6. Modification of hemiplegic compensatory gait pattern by symmetry-based motion controller of HAL.

    PubMed

    Kawamoto, Hiroaki; Kadone, Hideki; Sakurai, Takeru; Sankai, Yoshiyuki

    2015-01-01

    As one of several characteristics of hemiplegic patients after stroke, compensatory gait caused by affected limb is often seen. The purpose of this research is to apply a symmetry-based controller of a wearable type lower limb robot, Hybrid Assistive Limb (HAL) to hemiplegic patients with compensatory gait, and to investigate improvement of gait symmetry. The controller is designed respectively for swing phase and support phase according to characteristics of hemiplegic gait pattern. The controller during swing phase stores the motion of the unaffected limb and then provides motion support on the affected limb during the subsequent swing using the stored pattern to realize symmetric gait based on spontaneous limb swing. Moreover, the controller during support phase provides motion to extend hip and knee joints to support wearer's body. Clinical tests were conducted in order to assess the modification of gait symmetry. Our case study involved participation of one chronic stroke patient who performs abnormally-compensatory gait for both of the affected and unaffected limbs. As a result, the patient's gait symmetry was improved by providing motion support during the swing phase on the affected side and motion constraint during the support phase on the unaffected side. The study showed promising basis for the effectiveness of the controller for the future clinical study.

  7. Noninvasive tongue-motion controlled computer mouse for the disabled.

    PubMed

    Chou, C-H; Hwang, Y-S; Chen, C-C; Chen, S-C; Chou, S-W; Chen, Y-L

    2016-05-18

    A patient whose spinal cord was damaged due to accident may result in Tetraplegia or lose the ability to control his/her daily living environment. Currently, patients must use an invasive tool tongue movement, to help the patient communicate with the external environment. This study designed a non-invasive tongue movement computer mouse system that allows the patient to use tongue movement to control a computer to communicate with the external environment. Via a pressure sensor and assistive holder designed in this study, the pressure sensor can be moved using the assistive holder close to the mylohyoid muscle of the patient's lower jaw. The changes in pressure from the mylohyoid muscle are converted into computer mouse control signals to control a computer to communicate with the external environment. This study is based on ISO9241-Part 9 to design four kinds of training modes with varying difficulties. The data were collected from five able persons participating in the test over 7 days. The data includes throughput, path efficiency, test completion time and reaction time. The data verifies that the proposed system is stable and practical for persons with disabilities. The non-invasive computer mouse system for sensing tongue movement can completely breakthrough the limitations of the invasive tongue movement sensing system. This study uses non-invasive, simple tongue movements that correspond to the stretching and shrinking of the lower jaw mylohyoid muscle to control the computer mouse.

  8. INS/GNSS Integration for Aerobatic Flight Applications and Aircraft Motion Surveying

    PubMed Central

    v. Hinüber, Edgar L.; Reimer, Christian; Schneider, Tim; Stock, Michael

    2017-01-01

    This paper presents field tests of challenging flight applications obtained with a new family of lightweight low-power INS/GNSS (inertial navigation system/global satellite navigation system) solutions based on MEMS (micro-electro-mechanical- sensor) machined sensors, being used for UAV (unmanned aerial vehicle) navigation and control as well as for aircraft motion dynamics analysis and trajectory surveying. One key is a 42+ state extended Kalman-filter-based powerful data fusion, which also allows the estimation and correction of parameters that are typically affected by sensor aging, especially when applying MEMS-based inertial sensors, and which is not yet deeply considered in the literature. The paper presents the general system architecture, which allows iMAR Navigation the integration of all classes of inertial sensors and GNSS (global navigation satellite system) receivers from very-low-cost MEMS and high performance MEMS over FOG (fiber optical gyro) and RLG (ring laser gyro) up to HRG (hemispherical resonator gyro) technology, and presents detailed flight test results obtained under extreme flight conditions. As a real-world example, the aerobatic maneuvers of the World Champion 2016 (Red Bull Air Race) are presented. Short consideration is also given to surveying applications, where the ultimate performance of the same data fusion, but applied on gravimetric surveying, is discussed. PMID:28445417

  9. INS/GNSS Integration for Aerobatic Flight Applications and Aircraft Motion Surveying.

    PubMed

    V Hinüber, Edgar L; Reimer, Christian; Schneider, Tim; Stock, Michael

    2017-04-26

    This paper presents field tests of challenging flight applications obtained with a new family of lightweight low-power INS/GNSS (inertial navigation system/global satellite navigation system) solutions based on MEMS (micro-electro-mechanical- sensor) machined sensors, being used for UAV (unmanned aerial vehicle) navigation and control as well as for aircraft motion dynamics analysis and trajectory surveying. One key is a 42+ state extended Kalman-filter-based powerful data fusion, which also allows the estimation and correction of parameters that are typically affected by sensor aging, especially when applying MEMS-based inertial sensors, and which is not yet deeply considered in the literature. The paper presents the general system architecture, which allows iMAR Navigation the integration of all classes of inertial sensors and GNSS (global navigation satellite system) receivers from very-low-cost MEMS and high performance MEMS over FOG (fiber optical gyro) and RLG (ring laser gyro) up to HRG (hemispherical resonator gyro) technology, and presents detailed flight test results obtained under extreme flight conditions. As a real-world example, the aerobatic maneuvers of the World Champion 2016 (Red Bull Air Race) are presented. Short consideration is also given to surveying applications, where the ultimate performance of the same data fusion, but applied on gravimetric surveying, is discussed.

  10. 14 CFR 27.779 - Motion and effect of cockpit controls.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Motion and effect of cockpit controls. 27.779 Section 27.779 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... operate in accordance with the following movements and actuation: (a) Flight controls, including the...

  11. 14 CFR 29.779 - Motion and effect of cockpit controls.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Motion and effect of cockpit controls. 29.779 Section 29.779 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... operate in accordance with the following movements and actuation: (a) Flight controls, including the...

  12. 14 CFR 27.779 - Motion and effect of cockpit controls.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Motion and effect of cockpit controls. 27.779 Section 27.779 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... operate in accordance with the following movements and actuation: (a) Flight controls, including the...

  13. 14 CFR 29.779 - Motion and effect of cockpit controls.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Motion and effect of cockpit controls. 29.779 Section 29.779 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... operate in accordance with the following movements and actuation: (a) Flight controls, including the...

  14. 14 CFR 23.779 - Motion and effect of cockpit controls.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    .... Elevator Rearward for nose up. Rudder Right pedal forward for nose right. (2) Secondary controls: Flaps (or auxiliary lift devices) Forward or up for flaps up or auxiliary device stowed; rearward or down for flaps...: Motion and effect (1) Powerplant controls: Power (thrust) lever Forward to increase forward thrust and...

  15. 14 CFR 23.779 - Motion and effect of cockpit controls.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    .... Elevator Rearward for nose up. Rudder Right pedal forward for nose right. (2) Secondary controls: Flaps (or auxiliary lift devices) Forward or up for flaps up or auxiliary device stowed; rearward or down for flaps...: Motion and effect (1) Powerplant controls: Power (thrust) lever Forward to increase forward thrust and...

  16. 14 CFR 23.779 - Motion and effect of cockpit controls.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    .... Elevator Rearward for nose up. Rudder Right pedal forward for nose right. (2) Secondary controls: Flaps (or auxiliary lift devices) Forward or up for flaps up or auxiliary device stowed; rearward or down for flaps...: Motion and effect (1) Powerplant controls: Power (thrust) lever Forward to increase forward thrust and...

  17. 14 CFR 23.779 - Motion and effect of cockpit controls.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... Elevator Rearward for nose up. Rudder Right pedal forward for nose right. (2) Secondary controls: Flaps (or auxiliary lift devices) Forward or up for flaps up or auxiliary device stowed; rearward or down for flaps...: Motion and effect (1) Powerplant controls: Power (thrust) lever Forward to increase forward thrust and...

  18. Computer Controlled Interactive Motion and Still Image Film Projection System for Vocational Education for the Deaf.

    ERIC Educational Resources Information Center

    Fox, Raymond G.

    1978-01-01

    Describes a micro-processor controlled instruction delivery system being developed for use with deaf students which incorporates film cassette, frame or sequence addressable, color motion or still visuals under computer program control for local or remote delivery. An authoring capability for development and validation and a program are also…

  19. Controlling Motion Sickness and Spatial Disorientation and Enhancing Vestibular Rehabilitation with a User-Worn See-Through Display

    PubMed Central

    Krueger, Wesley W.O.

    2010-01-01

    Objectives/Hypotheses An eyewear mounted visual display (“User-worn see-through display”) projecting an artificial horizon aligned with the user's head and body position in space can prevent or lessen motion sickness in susceptible individuals when in a motion provocative environment as well as aid patients undergoing vestibular rehabilitation. In this project, a wearable display device, including software technology and hardware, was developed and a phase I feasibility study and phase II clinical trial for safety and efficacy were performed. Study Design Both phase I and phase II were prospective studies funded by the NIH. The phase II study used repeated measures for motion intolerant subjects and a randomized control group (display device/no display device) pre-post test design for patients in vestibular rehabilitation. Methods Following technology and display device development, 75 patients were evaluated by test and rating scales in the phase II study; 25 subjects with motion intolerance used the technology in the display device in provocative environments and completed subjective rating scales while 50 patients were evaluated before and after vestibular rehabilitation (25 using the display device and 25 in a control group) using established test measures. Results All patients with motion intolerance rated the technology as helpful for nine symptoms assessed, and 96% rated the display device as simple and easy to use. Duration of symptoms significantly decreased with use of the technology displayed. In patients undergoing vestibular rehabilitation, there were no significant differences in amount of change from pre- to post-therapy on objective balance tests between display device users and controls. However, those using the technology required significantly fewer rehabilitation sessions to achieve those outcomes than the control group. Conclusions A user-worn see-through display, utilizing a visual fixation target coupled with a stable artificial horizon

  20. Approaches to creating and controlling motion in MRI.

    PubMed

    Fischer, Gregory S; Cole, Gregory; Su, Hao

    2011-01-01

    Magnetic Resonance Imaging (MRI) can provide three dimensional (3D) imaging with excellent resolution and sensitivity making it ideal for guiding and monitoring interventions. The development of MRI-compatible interventional devices is complicated by factors including: the high magnetic field strength, the requirement that such devices should not degrade image quality, and the confined physical space of the scanner bore. Numerous MRI guided actuated devices have been developed or are currently being developed utilizing piezoelectric actuators as their primary means of mechanical energy generation to enable better interventional procedure performance. While piezoelectric actuators are highly desirable for MRI guided actuation for their precision, high holding force, and non-magnetic operation they are often found to cause image degradation on a large enough to scale to render live imaging unusable. This paper describes a newly developed piezoelectric actuator driver and control system designed to drive a variety of both harmonic and non-harmonic motors that has been demonstrated to be capable of operating both harmonic and non-harmonic piezoelectric actuators with less than 5% SNR loss under closed loop control. The proposed system device allows for a single controller to control any supported actuator and feedback sensor without any physical hardware changes.

  1. DNA Motion Induced by Electrokinetic Flow near an Au Coated Nanopore Surface as Voltage Controlled Gate

    PubMed Central

    Sugimoto, Manabu; Kato, Yuta; Ishida, Kentaro; Hyun, Changbae; Li, Jiali

    2014-01-01

    The diffusion and drift motion of λ DNA molecules on Au coated membrane surface near nanopores prior to their translocation through solid-state nanopores are investigated using fluorescence microscopy. With the capability of controlling electric potential at the Au surface as a gate voltage, Vgate, the motions of DNA molecules vary dramatically near the nanopores in our observations, presumably generated by electrokinetic flow. We carefully investigate theses DNA motions with different values of Vgate in order to alter the densities and polarities of counterions; which are expected to change the flow speed or direction, respectively. Depending on Vgate, our observations have revealed the critical distance from a nanopore for DNA molecules to be attracted or to be repelled, DNA’s anisotropic and unsteady drifting motions and accumulations of DNA molecules near the nanopore entrance. Further finite element method (FEM) numerical simulations indicate that the electrokinetic flow could explain these unusual DNA motions near metal collated gated nanopores qualitatively. Finally, we demonstrate the possibility to control the speed and direction of DNA motion near or through a nanopore, for example, recapturing a single DNA molecule multiple times with AC voltages on the Vgate. PMID:25611963

  2. DNA motion induced by electrokinetic flow near an Au coated nanopore surface as voltage controlled gate.

    PubMed

    Sugimoto, Manabu; Kato, Yuta; Ishida, Kentaro; Hyun, Changbae; Li, Jiali; Mitsui, Toshiyuki

    2015-02-13

    We used fluorescence microscopy to investigate the diffusion and drift motion of λ DNA molecules on an Au-coated membrane surface near nanopores, prior to their translocation through solid-state nanopores. With the capability of controlling electric potential at the Au surface as a gate voltage, Vgate, the motions of DNA molecules, which are presumably generated by electrokinetic flow, vary dramatically near the nanopores in our observations. We carefully investigate these DNA motions with different values of Vgate in order to alter the densities and polarities of the counterions, which are expected to change the flow speed or direction, respectively. Depending on Vgate, our observations have revealed the critical distance from a nanopore for DNA molecules to be attracted or repelled-DNA's anisotropic and unsteady drifting motions and accumulations of DNA molecules near the nanopore entrance. Further finite element method (FEM) numerical simulations indicate that the electrokinetic flow could qualitatively explain these unusual DNA motions near metal-collated gated nanopores. Finally, we demonstrate the possibility of controlling the speed and direction of DNA motion near or through a nanopore, as in the case of recapturing a single DNA molecule multiple times with alternating current voltages on the Vgate.

  3. Autogenic-Feedback Training for the Control of Space Motion Sickness

    NASA Technical Reports Server (NTRS)

    Cowings, Patricia S.; Toscano, W. B.

    1994-01-01

    This paper presents case-studies of 9 shuttle crewmembers (prime and alternates) and one U.S. Navy F-18 pilot, as they participated in all preflight training and testing activities in support of a life sciences flight experiment aboard Spacelab-J, and Spacelab-3. The primary objective of the flight experiment was to determine if Autogenic-feedback training (AFT), a physiological self-regulation training technique would be an effective treatment for motion sickness and space motion sickness in these crewmembers. Additional objectives of this study involved the examining human physiological responses to motion sickness on Earth and in space, as well as developing predictive criteria for susceptibility to space motion sickness based on ground-based data. Comparisons of these crewmembers are made to a larger set of subjects from previous experiments (treatment and "test-only" controls subjects). This paper describes all preflight methods, results and proposed changes for future tests.

  4. Autogenic-Feedback Training for the Control of Space Motion Sickness

    NASA Technical Reports Server (NTRS)

    Cowings, Patricia S.; Toscano, W. B.

    1994-01-01

    This paper presents case-studies of 9 shuttle crewmembers (prime and alternates) and one U.S. Navy F-18 pilot, as they participated in all preflight training and testing activities in support of a life sciences flight experiment aboard Spacelab-J, and Spacelab-3. The primary objective of the flight experiment was to determine if Autogenic-feedback training (AFT), a physiological self-regulation training technique would be an effective treatment for motion sickness and space motion sickness in these crewmembers. Additional objectives of this study involved the examining human physiological responses to motion sickness on Earth and in space, as well as developing predictive criteria for susceptibility to space motion sickness based on ground-based data. Comparisons of these crewmembers are made to a larger set of subjects from previous experiments (treatment and "test-only" controls subjects). This paper describes all preflight methods, results and proposed changes for future tests.

  5. Respiratory motion correction for PET oncology applications using affine transformation of list mode data.

    PubMed

    Lamare, F; Cresson, T; Savean, J; Cheze Le Rest, C; Reader, A J; Visvikis, D

    2007-01-07

    Respiratory motion is a source of artefacts and reduced image quality in PET. Proposed methodology for correction of respiratory effects involves the use of gated frames, which are however of low signal-to-noise ratio. Therefore a method accounting for respiratory motion effects without affecting the statistical quality of the reconstructed images is necessary. We have implemented an affine transformation of list mode data for the correction of respiratory motion over the thorax. The study was performed using datasets of the NCAT phantom at different points throughout the respiratory cycle. List mode data based PET simulated frames were produced by combining the NCAT datasets with a Monte Carlo simulation. Transformation parameters accounting for respiratory motion were estimated according to an affine registration and were subsequently applied on the original list mode data. The corrected and uncorrected list mode datasets were subsequently reconstructed using the one-pass list mode EM (OPL-EM) algorithm. Comparison of corrected and uncorrected respiratory motion average frames suggests that an affine transformation in the list mode data prior to reconstruction can produce significant improvements in accounting for respiratory motion artefacts in the lungs and heart. However, the application of a common set of transformation parameters across the imaging field of view does not significantly correct the respiratory effects on organs such as the stomach, liver or spleen.

  6. Spatial and Temporal Control of Hyperthermia Using Real Time Ultrasonic Thermal Strain Imaging with Motion Compensation, Phantom Study

    PubMed Central

    Foiret, Josquin; Ferrara, Katherine W.

    2015-01-01

    Mild hyperthermia has been successfully employed to induce reversible physiological changes that can directly treat cancer and enhance local drug delivery. In this approach, temperature monitoring is essential to avoid undesirable biological effects that result from thermal damage. For thermal therapies, Magnetic Resonance Imaging (MRI) has been employed to control real-time Focused Ultrasound (FUS) therapies. However, combined ultrasound imaging and therapy systems offer the benefits of simple, low-cost devices that can be broadly applied. To facilitate such technology, ultrasound thermometry has potential to reliably monitor temperature. Control of mild hyperthermia was previously achieved using a proportional-integral-derivative (PID) controller based on thermocouple measurements. Despite accurate temporal control of heating, this method is limited by the single position at which the temperature is measured. Ultrasound thermometry techniques based on exploiting the thermal dependence of acoustic parameters (such as longitudinal velocity) can be extended to create thermal maps and allow an accurate monitoring of temperature with good spatial resolution. However, in vivo applications of this technique have not been fully developed due to the high sensitivity to tissue motion. Here, we propose a motion compensation method based on the acquisition of multiple reference frames prior to treatment. The technique was tested in the presence of 2-D and 3-D physiological-scale motion and was found to provide effective real-time temperature monitoring. PID control of mild hyperthermia in presence of motion was then tested with ultrasound thermometry as feedback and temperature was maintained within 0.3°C of the requested value. PMID:26244783

  7. 75 FR 35007 - Portland Water Bureau; Notice of Application Accepted for Filing and Soliciting Comments, Motions...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-21

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Portland Water Bureau; Notice of Application Accepted for Filing and Soliciting Comments, Motions To Intervene, Protests, Recommendations, and Terms and Conditions June 15, 2010. Take notice that the...

  8. 77 FR 22312 - Notice of Preliminary Permit Application Accepted for Filing and Soliciting Comments, Motions To...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-13

    ... Soliciting Comments, Motions To Intervene, and Competing Applications On March 23, 2012, Cave Run Energy, LLC...' (Corps) Cave Run Dam, located on the Licking River in Rowan and Bath Counties, Kentucky. The sole purpose... generation of 34,164 megawatt-hours (MWh), and operate utilizing surplus water from the Cave Run Dam, as...

  9. Design and Implementation of an Electromagnetic Energy Harvester for Linear and Rotary Motion Applications

    NASA Astrophysics Data System (ADS)

    Hekmati, Alireza

    This thesis presents a new design for an electromagnetic energy harvester to be used in both linear and rotary motion applications. This electromagnetic energy harvester consists of a moving coil within a fixed magnetic circuit. This magnetic circuit comprises of a permanent magnet (as a magnetic source), a magnetic conductor (such as iron), and an air gap to create a space for coil movement inside energy harvester setup. In the parameter study of this electromagnetic energy harvester, it has been demonstrated that applying design modifications will improve the amount of induced voltage by %50. For linear motion applications, the energy harvester has been mounted on a linear motor and the experimental results indicated that when the coil movements' speed is 70 [mm/s], the maximum harvested power is 5.320 [mW]. For rotary motion applications, first a voice coil speaker has been used as a single degree of freedom system to produce voltage through a rotating beam and hub. Since in lower resonance frequencies, the maximum induced voltage is quite low, thus in next step, the two degrees of freedom energy harvesting system for rotary motion applications has been introduced. This system has been mounted on a car ring and the result illustrated that at the resonance frequency (15 [Hz]), the induced voltage was 0.175 [V] for each coil.

  10. The utility of motion parallax information for the perception and control of heading.

    PubMed

    Frey, B F; Owen, D H

    1999-04-01

    Two experiments in which participants were given control over the direction of computer-simulated self-motion were conducted. Environments were designed to evaluate the functionality of simple and multiple motion parallax as well as a separation ratio (sigma; indexing the separation of 2 objects in depth) for the perception and control of heading. Results provide a 1st indication of optimizing performance in the top end of the global optical flow velocity range available during human bipedal self-motion. The introduction of sigma, developed to explain performance improvements with decreasing distance to the target, was able to account for most of the performance differences among all simulated environments. The rate of change in horizontal optical separation between at least 2 discontinuities was identified as a likely candidate for the optical foundation of the perception and control of heading during target approach.

  11. Adaptive robust motion/force control of holonomic-constrained nonholonomic mobile manipulators.

    PubMed

    Li, Zhijun; Ge, Shuzhi Sam; Ming, Aiguo

    2007-06-01

    In this paper, adaptive robust force/motion control strategies are presented for mobile manipulators under both holonomic and nonholonomic constraints in the presence of uncertainties and disturbances. The proposed control is robust not only to parameter uncertainties such as mass variations but also to external ones such as disturbances. The stability of the closed-loop system and the boundedness of tracking errors are proved using Lyapunov stability synthesis. The proposed control strategies guarantee that the system motion converges to the desired manifold with prescribed performance and the bounded constraint force. Simulation results validate that the motion of the system converges to the desired trajectory, and the constraint force converges to the desired force.

  12. Development of Visual Motion Perception for Prospective Control: Brain and Behavioral Studies in Infants

    PubMed Central

    Agyei, Seth B.; van der Weel, F. R. (Ruud); van der Meer, Audrey L. H.

    2016-01-01

    During infancy, smart perceptual mechanisms develop allowing infants to judge time-space motion dynamics more efficiently with age and locomotor experience. This emerging capacity may be vital to enable preparedness for upcoming events and to be able to navigate in a changing environment. Little is known about brain changes that support the development of prospective control and about processes, such as preterm birth, that may compromise it. As a function of perception of visual motion, this paper will describe behavioral and brain studies with young infants investigating the development of visual perception for prospective control. By means of the three visual motion paradigms of occlusion, looming, and optic flow, our research shows the importance of including behavioral data when studying the neural correlates of prospective control. PMID:26903908

  13. Hybrid control of microvibration of high-tech facility under horizontal and vertical ground motion

    NASA Astrophysics Data System (ADS)

    Xu, You-Lin; Guo, An-Xin; Li, Hui; Ng, Chi-Lun

    2004-07-01

    Hybrid control platform is investigated in this paper for mitigating microvibration of a batch of high tech equipment installed in a high tech facility (building) subject to nearby road vehicle-induced horizontal and vertical ground motions. Hybrid control platform, on which high tech equipment is installed, is mounted on the building floor through a series of passive mounts and controlled by hydraulic actuators in both horizontal and vertical directions. The hybrid control platform is taken as an elastic body with significant bending modes of vibration, and a sub-optimal control algorithm is used to manipulate the hydraulic actuators with the actuator dynamics included. The governing equations of motion of the coupled platform-building system are established in the absolute coordinate to facilitate the feedback control and performance evaluation of the platform. The horizontal and vertical ground motions at the base of the building induced by nearby moving road vehicles are assumed to be random and statistically stationary processes. A typical three-story high tech building is selected as a case study. The case study shows that the ground motion and vibration of the high tech building are higher in the vertical direction than in the horizontal direction. The use of hybrid control platform can effectively reduce both horizontal and vertical microvibrations of a vast quantity of high tech equipment to the level satisfying the most stringent microscale velocity requirement specified in the BBN criteria.

  14. Controlling Motion at the Nanoscale: Rise of the Molecular Machines.

    PubMed

    Abendroth, John M; Bushuyev, Oleksandr S; Weiss, Paul S; Barrett, Christopher J

    2015-08-25

    As our understanding and control of intra- and intermolecular interactions evolve, ever more complex molecular systems are synthesized and assembled that are capable of performing work or completing sophisticated tasks at the molecular scale. Commonly referred to as molecular machines, these dynamic systems comprise an astonishingly diverse class of motifs and are designed to respond to a plethora of actuation stimuli. In this Review, we outline the conditions that distinguish simple switches and rotors from machines and draw from a variety of fields to highlight some of the most exciting recent examples of opportunities for driven molecular mechanics. Emphasis is placed on the need for controllable and hierarchical assembly of these molecular components to display measurable effects at the micro-, meso-, and macroscales. As in Nature, this strategy will lead to dramatic amplification of the work performed via the collective action of many machines organized in linear chains, on functionalized surfaces, or in three-dimensional assemblies.

  15. Adaptive neural network motion control of manipulators with experimental evaluations.

    PubMed

    Puga-Guzmán, S; Moreno-Valenzuela, J; Santibáñez, V

    2014-01-01

    A nonlinear proportional-derivative controller plus adaptive neuronal network compensation is proposed. With the aim of estimating the desired torque, a two-layer neural network is used. Then, adaptation laws for the neural network weights are derived. Asymptotic convergence of the position and velocity tracking errors is proven, while the neural network weights are shown to be uniformly bounded. The proposed scheme has been experimentally validated in real time. These experimental evaluations were carried in two different mechanical systems: a horizontal two degrees-of-freedom robot and a vertical one degree-of-freedom arm which is affected by the gravitational force. In each one of the two experimental set-ups, the proposed scheme was implemented without and with adaptive neural network compensation. Experimental results confirmed the tracking accuracy of the proposed adaptive neural network-based controller.

  16. Adaptive Neural Network Motion Control of Manipulators with Experimental Evaluations

    PubMed Central

    Puga-Guzmán, S.; Moreno-Valenzuela, J.; Santibáñez, V.

    2014-01-01

    A nonlinear proportional-derivative controller plus adaptive neuronal network compensation is proposed. With the aim of estimating the desired torque, a two-layer neural network is used. Then, adaptation laws for the neural network weights are derived. Asymptotic convergence of the position and velocity tracking errors is proven, while the neural network weights are shown to be uniformly bounded. The proposed scheme has been experimentally validated in real time. These experimental evaluations were carried in two different mechanical systems: a horizontal two degrees-of-freedom robot and a vertical one degree-of-freedom arm which is affected by the gravitational force. In each one of the two experimental set-ups, the proposed scheme was implemented without and with adaptive neural network compensation. Experimental results confirmed the tracking accuracy of the proposed adaptive neural network-based controller. PMID:24574910

  17. Nonlinear Dynamics and Chaotic Motions in Feedback Controlled Elastic Systems.

    DTIC Science & Technology

    1985-08-01

    mechanical oscillator ", "On slowly varying oscillations ", "Knotted Orbits and bifurcation sequences in periodically forced oscillations ", "Dynamics of a...each P.I. 2.1 Analytical Studies of Feedback Controlled Oscillators (P.J. Holmes, S. Wiggins (Grad. Student)) 2.1.1 Bifurcation studies. Local and...global bifurcation studies of nonlinear oscillators subject to linear and nonlinear feedback have been completed. The systems treated have the form x

  18. The influence of motion control shoes on the running gait of mature and young females.

    PubMed

    Lilley, Kim; Stiles, Vicky; Dixon, Sharon

    2013-03-01

    This study compared the running gait of mature and young females, and investigated the effect of a motion control shoe. First, it was hypothesised that in a neutral shoe, mature females would display significantly greater rearfoot eversion, knee internal rotation and external adductor moments when compared to a younger group. Secondly, the motion control shoe would reduce rearfoot eversion and knee internal rotation in both groups. Thirdly it was hypothesised that the motion control shoe would increase knee external adductor moment, through an increase in knee varus and moment arm. 15 mature (40-60 years) and 15 young (18-25 years) females performed 10 running trials at 3.5ms(-1)±5% over a force platform. Two shoes were tested, the Adidas Supernova Glide (neutral), and the Adidas Supernova Sequence (motion control). Ankle and knee joint dynamics were analysed for the right leg, and the mean of ten trials was calculated. Joint moments were calculated using inverse dynamics. In the neutral condition, mature females presented greater peak rearfoot eversion, knee internal rotation, and external adductor moments than young females (p<0.05). A motion control shoe significantly reduced peak rearfoot eversion and knee internal rotation among both groups (p<0.05). No between shoe differences in knee external adductor moment were observed. A motion control shoe is recommended to reduce risk of injury associated with rearfoot eversion and knee internal rotation in mature females. However since the knee external adductor moment is a variable commonly associated with medial knee loading it is suggested that alternative design features are required to influence this moment. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. Method for neural network control of motion using real-time environmental feedback

    NASA Technical Reports Server (NTRS)

    Buckley, Theresa M. (Inventor)

    1997-01-01

    A method of motion control for robotics and other automatically controlled machinery using a neural network controller with real-time environmental feedback. The method is illustrated with a two-finger robotic hand having proximity sensors and force sensors that provide environmental feedback signals. The neural network controller is taught to control the robotic hand through training sets using back- propagation methods. The training sets are created by recording the control signals and the feedback signal as the robotic hand or a simulation of the robotic hand is moved through a representative grasping motion. The data recorded is divided into discrete increments of time and the feedback data is shifted out of phase with the control signal data so that the feedback signal data lag one time increment behind the control signal data. The modified data is presented to the neural network controller as a training set. The time lag introduced into the data allows the neural network controller to account for the temporal component of the robotic motion. Thus trained, the neural network controlled robotic hand is able to grasp a wide variety of different objects by generalizing from the training sets.

  20. Spacecraft Formation Control and Estimation Via Improved Relative Motion Dynamics

    DTIC Science & Technology

    2017-03-30

    AFRL /RVSV 3550 Aberdeen Ave, SE 11. SPONSOR/MONITOR’S REPORT Kirtland AFB, NM 87117-5776 NUMBER(S) AFRL -RV-PS-TR-2017-0052 12. DISTRIBUTION...unlimited. 62 DISTRIBUTION LIST DTIC/OCP 8725 John J. Kingman Rd, Suite 0944 Ft Belvoir, VA 22060-6218 1 cy AFRL /RVIL Kirtland AFB, NM 87117-5776 2 cys Official Record Copy AFRL /RVSV/Thomas A. Lovell 1 cy ... AFRL -RV-PS- AFRL -RV-PS- TR-2017-0052 TR-2017-0052 SPACECRAFT FORMATION CONTROL AND

  1. Interfacing and Motion Control of the UNC Heliostat

    NASA Astrophysics Data System (ADS)

    McMains, Lee

    2002-04-01

    The interface between a PC and existing & planned components of a solar telescope (Heliostat) is being revamped and the new configuration is expected to reduce complexity while increasing the precision of collected data. The automated solar tracking system, controlled by the PC and run using planned Simu-Link modules, will be used with optical sensing equipment to collect data from the visible and near-visible spectrum. The Heliostat would be used in the classroom for increased understanding of the physical properties of the Sun. A progress report on this aspect of the project will be given.

  2. Controlled motion in an elastic world. Research project: Manipulation strategies for massive space payloads

    NASA Technical Reports Server (NTRS)

    Book, Wayne J.

    1992-01-01

    The flexibility of the drives and structures of controlled motion systems are presented as an obstacle to be overcome in the design of high performance motion systems, particularly manipulator arms. The task and the measure of performance to be applied determine the technology appropriate to overcome this obstacle. Included in the technologies proposed are control algorithms (feedback and feed forward), passive damping enhancement, operational strategies, and structural design. Modeling of the distributed, nonlinear system is difficult, and alternative approaches are discussed. The author presents personal perspectives on the history, status, and future directions in this area.

  3. Combining spanwise morphing, inline motion and model based optimization for force magnitude and direction control

    NASA Astrophysics Data System (ADS)

    Scheller, Johannes; Braza, Marianna; Triantafyllou, Michael

    2016-11-01

    Bats and other animals rapidly change their wingspan in order to control the aerodynamic forces. A NACA0013 type airfoil with dynamically changing span is proposed as a simple model to experimentally study these biomimetic morphing wings. Combining this large-scale morphing with inline motion allows to control both force magnitude and direction. Force measurements are conducted in order to analyze the impact of the 4 degree of freedom flapping motion on the flow. A blade-element theory augmented unsteady aerodynamic model is then used to derive optimal flapping trajectories.

  4. A superconducting reversible rectifier that controls the motion of magnetic flux quanta.

    PubMed

    Villegas, J E; Savel'ev, Sergey; Nori, Franco; Gonzalez, E M; Anguita, J V; García, R; Vicent, J L

    2003-11-14

    We fabricated a device that controls the motion of flux quanta in a niobium superconducting film grown on an array of nanoscale triangular pinning potentials. The controllable rectification of the vortex motion is due to the asymmetry of the fabricated magnetic pinning centers. The reversal in the direction of the vortex flow is explained by the interaction between the vortices trapped on the magnetic nanostructures and the interstitial vortices. The applied magnetic field and input current strength can tune both the polarity and magnitude of the rectified vortex flow. Our ratchet system is explained and modeled theoretically, taking the interactions between particles into consideration.

  5. Local respiratory motion correction for PET/CT imaging: Application to lung cancer

    SciTech Connect

    Lamare, F. Fernandez, P.; Fayad, H.; Visvikis, D.

    2015-10-15

    Purpose: Despite multiple methodologies already proposed to correct respiratory motion in the whole PET imaging field of view (FOV), such approaches have not found wide acceptance in clinical routine. An alternative can be the local respiratory motion correction (LRMC) of data corresponding to a given volume of interest (VOI: organ or tumor). Advantages of LRMC include the use of a simple motion model, faster execution times, and organ specific motion correction. The purpose of this study was to evaluate the performance of LMRC using various motion models for oncology (lung lesion) applications. Methods: Both simulated (NURBS based 4D cardiac-torso phantom) and clinical studies (six patients) were used in the evaluation of the proposed LRMC approach. PET data were acquired in list-mode and synchronized with respiration. The implemented approach consists first in defining a VOI on the reconstructed motion average image. Gated PET images of the VOI are subsequently reconstructed using only lines of response passing through the selected VOI and are used in combination with a center of gravity or an affine/elastic registration algorithm to derive the transformation maps corresponding to the respiration effects. Those are finally integrated in the reconstruction process to produce a motion free image over the lesion regions. Results: Although the center of gravity or affine algorithm achieved similar performance for individual lesion motion correction, the elastic model, applied either locally or to the whole FOV, led to an overall superior performance. The spatial tumor location was altered by 89% and 81% for the elastic model applied locally or to the whole FOV, respectively (compared to 44% and 39% for the center of gravity and affine models, respectively). This resulted in similar associated overall tumor volume changes of 84% and 80%, respectively (compared to 75% and 71% for the center of gravity and affine models, respectively). The application of the nonrigid

  6. [Motion control of moving mirror based on fixed-mirror adjustment in FTIR spectrometer].

    PubMed

    Li, Zhong-bing; Xu, Xian-ze; Le, Yi; Xu, Feng-qiu; Li, Jun-wei

    2012-08-01

    The performance of the uniform motion of the moving mirror, which is the only constant motion part in FTIR spectrometer, and the performance of the alignment of the fixed mirror play a key role in FTIR spectrometer, and affect the interference effect and the quality of the spectrogram and may restrict the precision and resolution of the instrument directly. The present article focuses on the research on the uniform motion of the moving mirror and the alignment of the fixed mirror. In order to improve the FTIR spectrometer, the maglev support system was designed for the moving mirror and the phase detection technology was adopted to adjust the tilt angle between the moving mirror and the fixed mirror. This paper also introduces an improved fuzzy PID control algorithm to get the accurate speed of the moving mirror and realize the control strategy from both hardware design and algorithm. The results show that the development of the moving mirror motion control system gets sufficient accuracy and real-time, which can ensure the uniform motion of the moving mirror and the alignment of the fixed mirror.

  7. Focused ultrasound treatment of VX2 tumors controlled by local harmonic motion.

    PubMed

    Curiel, Laura; Huang, Yuexi; Vykhodtseva, Natalia; Hynynen, Kullervo

    2009-06-07

    The purpose of this study was to evaluate the feasibility of using localized harmonic motion (LHM) to monitor and control focused ultrasound surgery (FUS) in VX2 tumors in vivo. FUS exposures were performed on 13 VX2 tumors implanted in nine rabbits. The same transducer induced coagulation and generated a localized oscillatory motion by periodically varying the radiation force. A separate diagnostic ultrasound transducer tracked motion by cross-correlating echo signals at different instances. A threshold in motion amplitude was instituted to cease exposure. Coagulation was confirmed by T2-weighted MR images, thermal dose obtained through MR thermometry and histological examinations. For tumor locations achieving coagulation, the LHM amplitude was 9% (p = 0.04) to 57% (p < 0.0001) lower than that before exposure. Control was successful for 74 (69%) out of 108 cases, with 52 (48%) reaching the threshold and achieving coagulation and 22 (21%) never reaching threshold nor coagulating. For the 34 (31%) unsuccessful exposures, 16 (15%) never reached the threshold but coagulation occurred, and 18 (16%) reached threshold without coagulation confirmed. Noise or radio-frequency signal changes explained motion over- or underestimation in 24 (22%) cases; the remaining 10 (9%) had other causes of error. The control was generally successful, but sudden change or noise in the acquired echo signal caused failure. Coagulation after exposure could be validated by comparing amplitudes before and after exposure.

  8. Adaptive sliding mode control for six-DOF relative motion of spacecraft with input constraint

    NASA Astrophysics Data System (ADS)

    Wu, Jinjie; Liu, Kun; Han, Dapeng

    2013-06-01

    This paper addresses the synchronized control problem of relative position and attitude for spacecraft with input constraint. First, using dual quaternion, the kinematic and dynamic models of the six-degree-of-freedom relative motion of spacecraft are introduced. Second, a new adaptive sliding mode control scheme is proposed to guarantee the globally asymptotic convergence of relative motion despite the presence of control input constraint, parametric uncertainties and external disturbances. A detailed stability analysis of the resulting closed-loop system is included. Finally, simulation results are presented to illustrate the validity and effectiveness of the proposed controller, which has the following properties: (1) explicit accounting for the problem of input constraint, (2) fast convergent rate and accurate results can be obtained, (3) no chattering phenomenon is present in the control torque and control force, (4) self-adaptive regulation law is dynamically adjusted to ensure the tracking errors tend to zero asymptotically, (5) the upper bounds of unknown variables are estimated dynamically.

  9. The paracrine control of vascular motion. A historical perspective.

    PubMed

    Nava, Eduardo; Llorens, Silvia

    2016-11-01

    During the last quarter of the past century, the leading role the endocrine and nervous systems had on the regulation of vasomotion, shifted towards a more paracrine-based regulation. This begun with the recognition of endothelial cells as active players of vascular control, when the vessel's intimal layer was identified as the main source of prostacyclin and was followed by the discovery of an endothelium-derived smooth muscle cell relaxing factor (EDRF). The new position acquired by endothelial cells prompted the discovery of other endothelium-derived regulatory products: vasoconstrictors, generally known as EDCFs, endothelin, and other vasodilators with hyperpolarizing properties (EDHFs). While this research was taking place, a quest for the discovery of the nature of EDRF carried back to a research line commenced a decade earlier: the recently found intracellular messenger cGMP and nitrovasodilators. Both were smooth muscle relaxants and appeared to interact in a hormonal fashion. Prejudice against an unconventional gaseous molecule delayed the acceptance that EDRF was nitric oxide (NO). When this happened, a new era of research that exceeded the vascular field commenced. The discovery of the pathway for NO synthesis from L-arginine involved the clever assembling of numerous unrelated observations of different areas of knowledge. The last ten years of research on the paracrine regulation of the vascular wall has shifted to perivascular fat (PVAT), which is beginning to be regarded as the fourth layer of the vascular wall. Starting with the discovery of an adipose-derived relaxing substance (ADRF), the role that different adipokines have on the paracrine control of vasomotion is now filling the research activity of many vascular pharmacology labs, and surprising interactions between the endothelium, PVAT and smooth muscle are being unveiled.

  10. The application of holography as a real-time three-dimensional motion picture camera

    NASA Technical Reports Server (NTRS)

    Kurtz, R. L.

    1973-01-01

    A historical introduction to holography is presented, as well as a basic description of sideband holography for stationary objects. A brief theoretical development of both time-dependent and time-independent holography is also provided, along with an analytical and intuitive discussion of a unique holographic arrangement which allows the resolution of front surface detail from an object moving at high speeds. As an application of such a system, a real-time three-dimensional motion picture camera system is discussed and the results of a recent demonstration of the world's first true three-dimensional motion picture are given.

  11. A novel application of motion analysis for detecting stress responses in embryos at different stages of development

    PubMed Central

    2013-01-01

    studied in the control treatments. Conclusion This innovative use of motion analysis incorporates data quantifying embryonic movements at a range of frequencies and so provides an holistic analysis of an embryo’s movement patterns. This technique has potential applications for quantifying embryonic responses to environmental stressors such as exposure to pharmaceuticals or pollutants, and also as an automated tool for developmental staging of embryos. PMID:23374982

  12. Motion Tracking System

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Integrated Sensors, Inc. (ISI), under NASA contract, developed a sensor system for controlling robot vehicles. This technology would enable a robot supply vehicle to automatically dock with Earth-orbiting satellites or the International Space Station. During the docking phase the ISI-developed sensor must sense the satellite's relative motion, then spin so the robot vehicle can adjust its motion to align with the satellite and slowly close until docking is completed. ISI used the sensing/tracking technology as the basis of its OPAD system, which simultaneously tracks an object's movement in six degrees of freedom. Applications include human limb motion analysis, assembly line position analysis and auto crash dummy motion analysis. The NASA technology is also the basis for Motion Analysis Workstation software, a package to simplify the video motion analysis process.

  13. Neural Control of Motion-to-Force Transitions with the Fingertip

    PubMed Central

    Venkadesan, Madhusudhan; Valero-Cuevas, Francisco J.

    2010-01-01

    The neural control of tasks such as rapid acquisition of precision pinch remains unknown. Therefore, we investigated the neural control of finger musculature when the index fingertip abruptly transitions from motion to static force production. Nine subjects produced a downward tapping motion followed by vertical fingertip force against a rigid surface. We simultaneously recorded three-dimensional fingertip force, plus the complete muscle coordination pattern using intramuscular electromyograms from all seven index finger muscles. We found that the muscle coordination pattern clearly switched from that for motion to that for isometric force ~5 ms before contact (p = 0.0004). Mathematical modeling and analysis revealed that the underlying neural control also switched between mutually incompatible strategies in a time-critical manner. Importantly, this abrupt switch in underlying neural control polluted fingertip force vector direction beyond what is explained by muscle activation-contraction dynamics and neuromuscular noise (p ≤0.003). We further ruled out an impedance control strategy in a separate test showing no systematic change in initial force magnitude for catch trials where the tapping surface was surreptitiously lowered and raised (p = 0.93). We conclude that the nervous system predictively switches between mutually incompatible neural control strategies to bridge the abrupt transition in mechanical constraints between motion and static force. Moreover because the nervous system cannot switch between control strategies instantaneously or exactly, there arise physical limits to the accuracy of force production on contact. The need for such a neurally demanding and time-critical strategy for routine motion-to-force transitions with the fingertip may explain the existence of specialized neural circuits for the human hand. PMID:18256256

  14. Neural control of motion-to-force transitions with the fingertip.

    PubMed

    Venkadesan, Madhusudhan; Valero-Cuevas, Francisco J

    2008-02-06

    The neural control of tasks such as rapid acquisition of precision pinch remains unknown. Therefore, we investigated the neural control of finger musculature when the index fingertip abruptly transitions from motion to static force production. Nine subjects produced a downward tapping motion followed by vertical fingertip force against a rigid surface. We simultaneously recorded three-dimensional fingertip force, plus the complete muscle coordination pattern using intramuscular electromyograms from all seven index finger muscles. We found that the muscle coordination pattern clearly switched from that for motion to that for isometric force approximately 65 ms before contact (p = 0.0004). Mathematical modeling and analysis revealed that the underlying neural control also switched between mutually incompatible strategies in a time-critical manner. Importantly, this abrupt switch in underlying neural control polluted fingertip force vector direction beyond what is explained by muscle activation-contraction dynamics and neuromuscular noise (p < or = 0.003). We further ruled out an impedance control strategy in a separate test showing no systematic change in initial force magnitude for catch trials where the tapping surface was surreptitiously lowered and raised (p = 0.93). We conclude that the nervous system predictively switches between mutually incompatible neural control strategies to bridge the abrupt transition in mechanical constraints between motion and static force. Moreover because the nervous system cannot switch between control strategies instantaneously or exactly, there arise physical limits to the accuracy of force production on contact. The need for such a neurally demanding and time-critical strategy for routine motion-to-force transitions with the fingertip may explain the existence of specialized neural circuits for the human hand.

  15. Instrument Remote Control Application Framework

    NASA Technical Reports Server (NTRS)

    Ames, Troy; Hostetter, Carl F.

    2006-01-01

    The Instrument Remote Control (IRC) architecture is a flexible, platform-independent application framework that is well suited for the control and monitoring of remote devices and sensors. IRC enables significant savings in development costs by utilizing extensible Markup Language (XML) descriptions to configure the framework for a specific application. The Instrument Markup Language (IML) is used to describe the commands used by an instrument, the data streams produced, the rules for formatting commands and parsing the data, and the method of communication. Often no custom code is needed to communicate with a new instrument or device. An IRC instance can advertise and publish a description about a device or subscribe to another device's description on a network. This simple capability of dynamically publishing and subscribing to interfaces enables a very flexible, self-adapting architecture for monitoring and control of complex instruments in diverse environments.

  16. Adaptive momentum-based motion detection approach and its application on handoff in wireless networks.

    PubMed

    Chung, Tein-Yaw; Chen, Yung-Mu; Hsu, Chih-Hung

    2009-01-01

    Positioning and tracking technologies can detect the location and the movement of mobile nodes (MNs), such as cellular phone, vehicular and mobile sensor, to predict potential handoffs. However, most motion detection mechanisms require additional hardware (e.g., GPS and directed antenna), costs (e.g., power consumption and monetary cost) and supply systems (e.g., network fingerprint server). This paper proposes a Momentum of Received Signal Strength (MRSS) based motion detection method and its application on handoff. MRSS uses the exponentially weighted moving average filter with multiple moving average window size to analyze the received radio signal. With MRSS, an MN can predict its motion state and make a handoff trigger at the right time without any assistance from positioning systems. Moreover, a novel motion state dependent MRSS scheme called Dynamic MRSS (DMRSS) algorithm is proposed to adjust the motion detection sensitivity. In our simulation, the MRSS- and DMRSS-based handoff algorithms can reduce the number of unnecessary handoffs up to 44% and save battery power up to 75%.

  17. Adaptive Momentum-Based Motion Detection Approach and Its Application on Handoff in Wireless Networks

    PubMed Central

    Chung, Tein-Yaw; Chen, Yung-Mu; Hsu, Chih-Hung

    2009-01-01

    Positioning and tracking technologies can detect the location and the movement of mobile nodes (MNs), such as cellular phone, vehicular and mobile sensor, to predict potential handoffs. However, most motion detection mechanisms require additional hardware (e.g., GPS and directed antenna), costs (e.g., power consumption and monetary cost) and supply systems (e.g., network fingerprint server). This paper proposes a Momentum of Received Signal Strength (MRSS) based motion detection method and its application on handoff. MRSS uses the exponentially weighted moving average filter with multiple moving average window size to analyze the received radio signal. With MRSS, an MN can predict its motion state and make a handoff trigger at the right time without any assistance from positioning systems. Moreover, a novel motion state dependent MRSS scheme called Dynamic MRSS (DMRSS) algorithm is proposed to adjust the motion detection sensitivity. In our simulation, the MRSS- and DMRSS-based handoff algorithms can reduce the number of unnecessary handoffs up to 44% and save battery power up to 75%. PMID:22346724

  18. Control of Dynamic Limb Motion Using Fatigue-Resistant Asynchronous Intrafascicular Multi-Electrode Stimulation

    PubMed Central

    Frankel, Mitchell A.; Mathews, V John; Clark, Gregory A.; Normann, Richard A.; Meek, Sanford G.

    2016-01-01

    Asynchronous intrafascicular multi-electrode stimulation (aIFMS) of small independent populations of peripheral nerve motor axons can evoke selective, fatigue-resistant muscle forces. We previously developed a real-time proportional closed-loop control method for aIFMS generation of isometric muscle force and the present work extends and adapts this closed-loop controller to the more demanding task of dynamically controlling joint position in the presence of opposing joint torque. A proportional-integral-velocity controller, with integrator anti-windup strategies, was experimentally validated as a means to evoke motion about the hind-limb ankle joint of an anesthetized feline via aIFMS stimulation of fast-twitch plantar-flexor muscles. The controller was successful in evoking steps in joint position with 2.4% overshoot, 2.3-s rise time, 4.5-s settling time, and near-zero steady-state error. Controlled step responses were consistent across changes in step size, stable against external disturbances, and reliable over time. The controller was able to evoke smooth eccentric motion at joint velocities up to 8 deg./s, as well as sinusoidal trajectories with frequencies up to 0.1 Hz, with time delays less than 1.5 s. These experiments provide important insights toward creating a robust closed-loop aIFMS controller that can evoke precise fatigue-resistant motion in paralyzed individuals, despite the complexities introduced by aIFMS. PMID:27679557

  19. A Comparative Study Of Motion Estimation Techniques For Application To Sub-Sea Robotics

    NASA Astrophysics Data System (ADS)

    Russell, George T.; Wells, Stuart C.

    1984-02-01

    As the complexity of sub-sea maintenance and inspection tasks increases, and the search for further reserves of offshore oil goes into deeper and more hazardous environmental conditions, the need for autonomous working submersibles is increased. The total free swimming submersible system requires a scope that embraces the guidance and control of the vehicle and associated payload, the acquisition and processing of information, and the communication of that information between the vehicle and the surface operator. This paper describes an important aspect of the total system, namely, the technique employed in reducing the required bandwidth for the transmission of television pictures, through an acoustic communication link. In particular, the estimation of motion within an image sequence has been shown to offer a further refinement in bandwidth reduction when used in conjunction with interframe hybrid coding. Many competing techniques have been proposed in the literature. The objective of this study has been to compare a range of fundamental techniques, in order to optimise the communication system design for this particular application. An essential by-product of this investigation has been the development of a general image processing system that incorporates a set of interactive image processing modules and provides a real-time colour picture capture and display facility.

  20. Experimental investigations of the controlled motion of a screwless underwater robot

    NASA Astrophysics Data System (ADS)

    Karavaev, Yury L.; Kilin, Alexander A.; Klekovkin, Anton V.

    2016-12-01

    In this paper we describe the results of experimental investigations of the motion of a screwless underwater robot controlled by rotating internal rotors. We present the results of comparison of the trajectories obtained with the results of numerical simulation using the model of an ideal fluid.

  1. Vestibular Stimulation for ADHD: Randomized Controlled Trial of Comprehensive Motion Apparatus

    ERIC Educational Resources Information Center

    Clark, David L.; Arnold, L. Eugene; Crowl, Lindsay; Bozzolo, Hernan; Peruggia, Mario; Ramadan, Yaser; Bornstein, Robert; Hollway, Jill A.; Thompson, Susan; Malone, Krista; Hall, Kristy L.; Shelton, Sara B.; Bozzolo, Dawn R.; Cook, Amy

    2008-01-01

    Objective: This research evaluates effects of vestibular stimulation by Comprehensive Motion Apparatus (CMA) in ADHD. Method: Children ages 6 to 12 (48 boys, 5 girls) with ADHD were randomized to thrice-weekly 30-min treatments for 12 weeks with CMA, stimulating otoliths and semicircular canals, or a single-blind control of equal duration and…

  2. Motion Controllers for Learners to Manipulate and Interact with 3D Objects for Mental Rotation Training

    ERIC Educational Resources Information Center

    Yeh, Shih-Ching; Wang, Jin-Liang; Wang, Chin-Yeh; Lin, Po-Han; Chen, Gwo-Dong; Rizzo, Albert

    2014-01-01

    Mental rotation is an important spatial processing ability and an important element in intelligence tests. However, the majority of past attempts at training mental rotation have used paper-and-pencil tests or digital images. This study proposes an innovative mental rotation training approach using magnetic motion controllers to allow learners to…

  3. Design and Evaluation of an Integrated Online Motion Control Training Package

    ERIC Educational Resources Information Center

    Buiu, C.

    2009-01-01

    The aim of this paper is to present an integrated Internet-based package for teaching the fundamentals of motion control by using a wide range of resources: theory, videos, simulators, games, quizzes, and a remote lab. The package is aimed at automation technicians, pupils at vocational schools and students taking an introductory course in…

  4. Experimentally realizable devices for controlling the motion of magnetic flux quanta in anisotropic superconductors.

    PubMed

    Savel'ev, Sergey; Nori, Franco

    2002-11-01

    A new generation of microscopic ratchet systems is currently being developed for controlling the motion of electrons and fluxons, as well as for particle separation and electrophoresis. Virtually all of these use static spatially asymmetric potential energies to control transport properties. Here we propose completely new types of ratchet-like systems that do not require fixed spatially asymmetric potentials in the samples. As specific examples of this novel general class of ratchets, we propose devices that control the motion of flux quanta in superconductors and could address a central problem in many superconducting devices; namely, the removal of trapped magnetic flux that produces noise. In layered superconductors there are two interpenetrating perpendicular vortex lattices consisting of Josephson vortices (JVs) and pancake vortices (PVs). We show that, owing to the JV-PV mutual interaction and asymmetric driving, the a.c. motion of JVs and/or PVs can provide a net d.c. vortex current. This controllable vortex motion can be used for making pumps, diodes and lenses of quantized magnetic flux. These proposed devices sculpt the microscopic magnetic flux profile by simply modifying the time dependence of the a.c. drive, without the need for samples with static pinning--for example, without lithography or irradiation.

  5. Safety analysis forseismic motion of control rods accounting for rod misalignment

    SciTech Connect

    Osmin, W.L.; Paik, I.K.

    1992-01-01

    The purpose of this report is to provide a summary of the results of three safety analyses performed by the SRL Safety Analysis Group (SAG) to assess the safety impact of control rod motion induced by a Design Basis Earthquake (DBE).

  6. Design and Evaluation of an Integrated Online Motion Control Training Package

    ERIC Educational Resources Information Center

    Buiu, C.

    2009-01-01

    The aim of this paper is to present an integrated Internet-based package for teaching the fundamentals of motion control by using a wide range of resources: theory, videos, simulators, games, quizzes, and a remote lab. The package is aimed at automation technicians, pupils at vocational schools and students taking an introductory course in…

  7. Motion Controllers for Learners to Manipulate and Interact with 3D Objects for Mental Rotation Training

    ERIC Educational Resources Information Center

    Yeh, Shih-Ching; Wang, Jin-Liang; Wang, Chin-Yeh; Lin, Po-Han; Chen, Gwo-Dong; Rizzo, Albert

    2014-01-01

    Mental rotation is an important spatial processing ability and an important element in intelligence tests. However, the majority of past attempts at training mental rotation have used paper-and-pencil tests or digital images. This study proposes an innovative mental rotation training approach using magnetic motion controllers to allow learners to…

  8. Motion-Based System Identification and Fault Detection and Isolation Technologies for Thruster Controlled Spacecraft

    NASA Technical Reports Server (NTRS)

    Wilson, Edward; Sutter, David W.; Berkovitz, Dustin; Betts, Bradley J.; Kong, Edmund; delMundo, Rommel; Lages, Christopher R.; Mah, Robert W.; Papasin, Richard

    2003-01-01

    By analyzing the motions of a thruster-controlled spacecraft, it is possible to provide on-line (1) thruster fault detection and isolation (FDI), and (2) vehicle mass- and thruster-property identification (ID). Technologies developed recently at NASA Ames have significantly improved the speed and accuracy of these ID and FDI capabilities, making them feasible for application to a broad class of spacecraft. Since these technologies use existing sensors, the improved system robustness and performance that comes with the thruster fault tolerance and system ID can be achieved through a software-only implementation. This contrasts with the added cost, mass, and hardware complexity commonly required by FDI. Originally developed in partnership with NASA - Johnson Space Center to provide thruster FDI capability for the X-38 during re-entry, these technologies are most recently being applied to the MIT SPHERES experimental spacecraft to fly on the International Space Station in 2004. The model-based FDI uses a maximum-likelihood calculation at its core, while the ID is based upon recursive least squares estimation. Flight test results from the SPHERES implementation, as flown aboard the NASA KC-1 35A 0-g simulator aircraft in November 2003 are presented.

  9. Stabilized atomic force microscopy imaging in liquids using second harmonic of cantilever motion for setpoint control

    NASA Astrophysics Data System (ADS)

    Schiener, Jens; Witt, Susanne; Stark, Martin; Guckenberger, Reinhard

    2004-08-01

    We present an automated stabilization of the imaging process in tapping mode atomic force microscopy. For biological applications, the requirement of stable imaging conditions to achieve reliable high resolution is contradicted by the necessity to work in solution to ensure biological functionality: thermal and saline variations of the viscosity, in particular when exchanging the solution the sample is surrounded with, strongly affect the cantilever motion rendering the imaging process instable. Using anharmonic contributions in the deflection signal, the amplitude setpoint is controlled to compensate for unavoidable drift in the free oscillation. By this additional feedback, the tip-sample interaction is maintained stable at a low value, making the instrument robust against drift and tolerant to environmental changes. As a delicate test sample, the "single ring"-mutant of the bacterial chaperonin GroEL from E. coli was imaged. To prove the efficiency of our setup, we show highly stabilized, continuous imaging with minimized user interaction while strong perturbations by exchange of the buffer solution were imposed during the scanning.

  10. Using EMG to anticipate head motion for virtual-environment applications

    NASA Technical Reports Server (NTRS)

    Barniv, Yair; Aguilar, Mario; Hasanbelliu, Erion

    2005-01-01

    In virtual environment (VE) applications, where virtual objects are presented in a see-through head-mounted display, virtual images must be continuously stabilized in space in response to user's head motion. Time delays in head-motion compensation cause virtual objects to "swim" around instead of being stable in space which results in misalignment errors when overlaying virtual and real objects. Visual update delays are a critical technical obstacle for implementing head-mounted displays in applications such as battlefield simulation/training, telerobotics, and telemedicine. Head motion is currently measurable by a head-mounted 6-degrees-of-freedom inertial measurement unit. However, even given this information, overall VE-system latencies cannot be reduced under about 25 ms. We present a novel approach to eliminating latencies, which is premised on the fact that myoelectric signals from a muscle precede its exertion of force, thereby limb or head acceleration. We thus suggest utilizing neck-muscles' myoelectric signals to anticipate head motion. We trained a neural network to map such signals onto equivalent time-advanced inertial outputs. The resulting network can achieve time advances of up to 70 ms.

  11. Using EMG to anticipate head motion for virtual-environment applications

    NASA Technical Reports Server (NTRS)

    Barniv, Yair; Aguilar, Mario; Hasanbelliu, Erion

    2005-01-01

    In virtual environment (VE) applications, where virtual objects are presented in a see-through head-mounted display, virtual images must be continuously stabilized in space in response to user's head motion. Time delays in head-motion compensation cause virtual objects to "swim" around instead of being stable in space which results in misalignment errors when overlaying virtual and real objects. Visual update delays are a critical technical obstacle for implementing head-mounted displays in applications such as battlefield simulation/training, telerobotics, and telemedicine. Head motion is currently measurable by a head-mounted 6-degrees-of-freedom inertial measurement unit. However, even given this information, overall VE-system latencies cannot be reduced under about 25 ms. We present a novel approach to eliminating latencies, which is premised on the fact that myoelectric signals from a muscle precede its exertion of force, thereby limb or head acceleration. We thus suggest utilizing neck-muscles' myoelectric signals to anticipate head motion. We trained a neural network to map such signals onto equivalent time-advanced inertial outputs. The resulting network can achieve time advances of up to 70 ms.

  12. Injury risk in runners using standard or motion control shoes: a randomised controlled trial with participant and assessor blinding.

    PubMed

    Malisoux, Laurent; Chambon, Nicolas; Delattre, Nicolas; Gueguen, Nils; Urhausen, Axel; Theisen, Daniel

    2016-04-01

    This randomised controlled trial investigated if the usage of running shoes with a motion control system modifies injury risk in regular leisure-time runners compared to standard shoes, and if this influence depends on foot morphology. Recreational runners (n=372) were given either the motion control or the standard version of a regular running shoe model and were followed up for 6 months regarding running activity and injury. Foot morphology was analysed using the Foot Posture Index method. Cox regression analyses were used to compare injury risk between the two groups, based on HRs and their 95% CIs, controlling for potential confounders. Stratified analyses were conducted to evaluate the effect of motion control system in runners with supinated, neutral and pronated feet. The overall injury risk was lower among the participants who had received motion control shoes (HR=0.55; 95% CI 0.36 to 0.85) compared to those receiving standard shoes. This positive effect was only observed in the stratum of runners with pronated feet (n=94; HR=0.34; 95% CI 0.13 to 0.84); there was no difference in runners with neutral (n=218; HR=0.78; 95% CI 0.44 to 1.37) or supinated feet (n=60; HR=0.59; 95% CI 0.20 to 1.73). Runners with pronated feet using standard shoes had a higher injury risk compared to those with neutral feet (HR=1.80; 95% CI 1.01 to 3.22). The overall injury risk was lower in participants who had received motion control shoes. Based on secondary analysis, those with pronated feet may benefit most from this shoe type. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  13. Injury risk in runners using standard or motion control shoes: a randomised controlled trial with participant and assessor blinding

    PubMed Central

    Malisoux, Laurent; Chambon, Nicolas; Delattre, Nicolas; Gueguen, Nils; Urhausen, Axel; Theisen, Daniel

    2016-01-01

    Background/aim This randomised controlled trial investigated if the usage of running shoes with a motion control system modifies injury risk in regular leisure-time runners compared to standard shoes, and if this influence depends on foot morphology. Methods Recreational runners (n=372) were given either the motion control or the standard version of a regular running shoe model and were followed up for 6 months regarding running activity and injury. Foot morphology was analysed using the Foot Posture Index method. Cox regression analyses were used to compare injury risk between the two groups, based on HRs and their 95% CIs, controlling for potential confounders. Stratified analyses were conducted to evaluate the effect of motion control system in runners with supinated, neutral and pronated feet. Results The overall injury risk was lower among the participants who had received motion control shoes (HR=0.55; 95% CI 0.36 to 0.85) compared to those receiving standard shoes. This positive effect was only observed in the stratum of runners with pronated feet (n=94; HR=0.34; 95% CI 0.13 to 0.84); there was no difference in runners with neutral (n=218; HR=0.78; 95% CI 0.44 to 1.37) or supinated feet (n=60; HR=0.59; 95% CI 0.20 to 1.73). Runners with pronated feet using standard shoes had a higher injury risk compared to those with neutral feet (HR=1.80; 95% CI 1.01 to 3.22). Conclusions The overall injury risk was lower in participants who had received motion control shoes. Based on secondary analysis, those with pronated feet may benefit most from this shoe type. PMID:26746907

  14. Motion control of the ankle joint with a multiple contact nerve cuff electrode: a simulation study.

    PubMed

    Park, Hyun-Joo; Durand, Dominique M

    2014-08-01

    The flat interface nerve electrode (FINE) has demonstrated significant capability for fascicular and subfascicular stimulation selectivity. However, due to the inherent complexity of the neuromuscular skeletal systems and nerve-electrode interface, a trajectory tracking motion control algorithm of musculoskeletal systems for functional electrical stimulation using a multiple contact nerve cuff electrode such as FINE has not yet been developed. In our previous study, a control system was developed for multiple-input multiple-output (MIMO) musculoskeletal systems with little prior knowledge of the system. In this study, more realistic computational ankle/subtalar joint model including a finite element model of the sciatic nerve was developed. The control system was tested to control the motion of ankle/subtalar joint angles by modulating the pulse amplitude of each contact of a FINE placed on the sciatic nerve. The simulation results showed that the control strategy based on the separation of steady state and dynamic properties of the system resulted in small output tracking errors for different reference trajectories such as sinusoidal and filtered random signals. The proposed control method also demonstrated robustness against external disturbances and system parameter variations such as muscle fatigue. These simulation results under various circumstances indicate that it is possible to take advantage of multiple contact nerve electrodes with spatial selectivity for the control of limb motion by peripheral nerve stimulation even with limited individual muscle selectivity. This technology could be useful to restore neural function in patients with paralysis.

  15. Control over molecular motion using the cis–trans photoisomerization of the azo group

    PubMed Central

    Ribagorda, María

    2012-01-01

    Summary Control over molecular motion represents an important objective in modern chemistry. Aromatic azobenzenes are excellent candidates as molecular switches since they can exist in two forms, namely the cis (Z) and trans (E) isomers, which can interconvert both photochemically and thermally. This transformation induces a molecular movement and a significant geometric change, therefore the azobenzene unit is an excellent candidate to build dynamic molecular devices. We describe selected examples of systems containing an azobenzene moiety and their motions and geometrical changes caused by external stimuli. PMID:23019434

  16. Electric-field control of magnetic domain wall motion and local magnetization reversal

    PubMed Central

    Lahtinen, Tuomas H. E.; Franke, Kévin J. A.; van Dijken, Sebastiaan

    2012-01-01

    Spintronic devices currently rely on magnetic switching or controlled motion of domain walls by an external magnetic field or spin-polarized current. Achieving the same degree of magnetic controllability using an electric field has potential advantages including enhanced functionality and low power consumption. Here we report on an approach to electrically control local magnetic properties, including the writing and erasure of regular ferromagnetic domain patterns and the motion of magnetic domain walls, in CoFe-BaTiO3 heterostructures. Our method is based on recurrent strain transfer from ferroelastic domains in ferroelectric media to continuous magnetostrictive films with negligible magnetocrystalline anisotropy. Optical polarization microscopy of both ferromagnetic and ferroelectric domain structures reveals that domain correlations and strong inter-ferroic domain wall pinning persist in an applied electric field. This leads to an unprecedented electric controllability over the ferromagnetic microstructure, an accomplishment that produces giant magnetoelectric coupling effects and opens the way to electric-field driven spintronics. PMID:22355770

  17. Reconstruction-Incorporated Respiratory Motion Correction in Clinical Simultaneous PET/MR Imaging for Oncology Applications.

    PubMed

    Fayad, Hadi; Schmidt, Holger; Wuerslin, Christian; Visvikis, Dimitris

    2015-06-01

    Simultaneous PET and MR imaging is a promising new technique allowing the fusion of functional (PET) and anatomic/functional (MR) information. In the thoracic-abdominal regions, respiratory motion is a major challenge leading to reduced quantitative and qualitative image accuracy. Correction methodologies include the use of gated frames that lead to low signal-to-noise ratio considering the associated low statistics. More advanced correction approaches, previously developed for PET/CT imaging, consist of either registering all the reconstructed gated frames to the reference frame or incorporating motion parameters into the iterative reconstruction process to produce a single motion-compensated PET image. The goal of this work was to compare these two—previously implemented in PET/CT—correction approaches within the context of PET/MR motion correction for oncology applications using clinical 4-dimensional PET/MR acquisitions. Two different correction approaches were evaluated comparing the incorporation of elastic transformations extracted from 4-dimensional MR imaging datasets during PET list-mode image reconstruction to a postreconstruction image-based approach. Eleven patient datasets acquired on a PET/MR system were used. T1-weighted 4D MR images were registered to the end-expiration image using a nonrigid B-spline registration algorithm to derive deformation matrices accounting for respiratory motion. The derived matrices were subsequently incorporated within a PET image reconstruction of the original emission list-mode data (reconstruction space [RS] method). The corrected images were compared with those produced by applying the deformation matrices in the image space (IS method) followed by summing the realigned gated frames, as well as with uncorrected motion-averaged images. Both correction techniques led to significant improvement in accounting for respiratory motion artifacts when compared with uncorrected motion-averaged images. These improvements

  18. Robotically controlled slosh-free motion of an open container of liquid

    SciTech Connect

    Feddema, J.; Dohrmann, C.; Parker, G.; Robinett, R.; Romero, V.; Schmitt, D.

    1995-10-01

    This paper describes two methods for controlling the surface of a liquid in an open container as it is being carried by a robot arm. Both methods make use of the fundamental mode of oscillation and damping of the liquid in the container as predicted from a boundary element model of the fluid. The first method uses an infinite impulse response filter to alter an acceleration profile so that the liquid remains level except for a single wave at the beginning and end of the motion. The motion of the liquid is similar to that of a simple pendulum. The second method removes the remaining two surface oscillations by tilting the container parallel to the beginning and ending wave. A double pendulum model is used to determine the trajectory for this motion. Experimental results of a FANUC S-800 robot moving a 230 mm diameter hemispherical container of water are presented.

  19. Vibrating barrier: a novel device for the passive control of structures under ground motion.

    PubMed

    Cacciola, P; Tombari, A

    2015-07-08

    A novel device, called vibrating barrier (ViBa), that aims to reduce the vibrations of adjacent structures subjected to ground motion waves is proposed. The ViBa is a structure buried in the soil and detached from surrounding buildings that is able to absorb a significant portion of the dynamic energy arising from the ground motion. The working principle exploits the dynamic interaction among vibrating structures due to the propagation of waves through the soil, namely the structure-soil-structure interaction. The underlying theoretical aspects of the novel control strategy are scrutinized along with its numerical modelling. Closed-form solutions are also derived to design the ViBa in the case of harmonic excitation. Numerical and experimental analyses are performed in order to investigate the efficiency of the device in mitigating the effects of ground motion waves on the structural response. A significant reduction in the maximum structural acceleration of 87% has been achieved experimentally.

  20. Vibrating barrier: a novel device for the passive control of structures under ground motion

    PubMed Central

    Cacciola, P.; Tombari, A.

    2015-01-01

    A novel device, called vibrating barrier (ViBa), that aims to reduce the vibrations of adjacent structures subjected to ground motion waves is proposed. The ViBa is a structure buried in the soil and detached from surrounding buildings that is able to absorb a significant portion of the dynamic energy arising from the ground motion. The working principle exploits the dynamic interaction among vibrating structures due to the propagation of waves through the soil, namely the structure–soil–structure interaction. The underlying theoretical aspects of the novel control strategy are scrutinized along with its numerical modelling. Closed-form solutions are also derived to design the ViBa in the case of harmonic excitation. Numerical and experimental analyses are performed in order to investigate the efficiency of the device in mitigating the effects of ground motion waves on the structural response. A significant reduction in the maximum structural acceleration of 87% has been achieved experimentally. PMID:26345731

  1. Split-belt controllable treadmill with differential velocity-based fall stimulation and motion analysis.

    PubMed

    Nakashima, Yasutaka; Noutsuka, Hiroki; Fukui, Takanori; Yamamoto, Motoji

    2016-08-01

    Amid trends toward aging populations in developed nations, the number of people requiring nursing care has increased markedly. Slips and falls during ordinary daily activities are a common cause of fractured bones and muscle injury. Several studies have analyzed the movements produced by artificially generated slip and fall stimuli, but few have investigated these stimuli. We analyzed lower-limb motion following a slip and fall stimulus produced using a pulled free-walking system consisting of a controllable split-belt treadmill, where a speed difference between the belts could be applied to produce a slipping motion. In three male participants, we established slip motion by applying acceleration in the sagittal plane direction of the right leg immediately upon contact with the treadmill. Each participant demonstrated a different recovery method from falling.

  2. The vestibular system: multimodal integration and encoding of self-motion for motor control

    PubMed Central

    Cullen, Kathleen E.

    2014-01-01

    Understanding how sensory pathways transmit information under natural conditions remains a major goal in neuroscience. The vestibular system plays a vital role in everyday life, contributing to a wide range of functions from reflexes to the highest levels of voluntary behavior. Recent experiments establishing that vestibular (self-motion) processing is inherently multimodal also provide insight into a set of interrelated questions: What neural code is used to represent sensory information in vestibular pathways? How does the organism’s interaction with the environment shape encoding? How is self-motion information processing adjusted to meet the needs of specific tasks? This review highlights progress that has recently been made towards understanding how the brain encodes and processes self-motion to ensure accurate motor control. PMID:22245372

  3. Hydrodynamic ratchet: Controlled motion of a polymer in an alternating microchannel flow

    NASA Astrophysics Data System (ADS)

    Zhang, Zhen; Stark, Holger; Mikhailov, Alexander S.

    2013-10-01

    Using ratchets, periodic or irregular oscillations can be transformed into steady translational or rotational motions. Here, we consider a model system that operates as a hydrodynamic ratchet. A polymer is placed inside a narrow channel where an oscillating Poiseuille flow is externally created. The ratchet mechanism is implemented by introducing a feedback control for the lateral position of the polymer through which its mobility becomes effectively dependent on the direction of its motion along the channel. We employ the semi-flexible elastic chain modeling for the polymer and use the method of multi-particle collision dynamics to simulate the fluid. We indeed observe directed motion of the polymer and determine the dependence of the propagation velocity on the model parameters.

  4. Motion generated in the unstable cervical spine during the application and removal of cervical immobilization collars.

    PubMed

    Prasarn, Mark L; Conrad, Bryan; Del Rossi, Gianluca; Horodyski, MaryBeth; Rechtine, Glenn R

    2012-06-01

    Many studies have compared the restriction of motion that immobilization collars provide to the injured victim. No previous investigation has assessed the amount of motion that is generated during the fitting and removal process. The purpose of this study was to compare the three-dimensional motion generated when one-piece and two-piece cervical collars are applied and removed from cadavers intact and with unstable cervical spine injuries. Five fresh, lightly embalmed cadavers were tested three times each with either a one-piece or two-piece cervical collar in the supine position. Testing was performed in the intact state, following creation of a global ligamentous instability at C5-C6. The amount of angular motion resulting from the collar application and removal was measured using a Fastrak, three-dimensional, electromagnetic motion analysis device (Polhemus Inc., Colchester, VT). The measurements recorded in this investigation included maximum values for flexion/extension, axial rotation, medial/lateral flexion, anterior/posterior displacement, axial distraction, and medial/lateral displacement at the level of instability. There was statistically more motion observed with application or removal of either collar following the creation of a global instability. During application, there was a statistically significant difference in flexion/extension between the one-piece (1.8 degrees) and two-piece (2.6 degrees) collars, p = 0.009. There was also a statistically significant difference in anterior/posterior translation between the one-piece (3.6 mm) and two-piece (3.4 mm) collars, p = 0.015. The maximum angulation and displacement during the application of either collar was 3.4 degrees and 4.4 mm. Statistical analysis revealed no significant differences between the one-piece and two-piece collars during the removal process. The maximum angulation and displacement during removal of either collar type was 1.6 degrees and 2.9 mm. There were statistically significant

  5. Motion Perception and Manual Control Performance During Passive Tilt and Translation Following Space Flight

    NASA Technical Reports Server (NTRS)

    Clement, Gilles; Wood, Scott J.

    2010-01-01

    This joint ESA-NASA study is examining changes in motion perception following Space Shuttle flights and the operational implications of post-flight tilt-translation ambiguity for manual control performance. Vibrotactile feedback of tilt orientation is also being evaluated as a countermeasure to improve performance during a closed-loop nulling task. METHODS. Data has been collected on 5 astronaut subjects during 3 preflight sessions and during the first 8 days after Shuttle landings. Variable radius centrifugation (216 deg/s) combined with body translation (12-22 cm, peak-to-peak) is utilized to elicit roll-tilt perception (equivalent to 20 deg, peak-to-peak). A forward-backward moving sled (24-390 cm, peak-to-peak) with or without chair tilting in pitch is utilized to elicit pitch tilt perception (equivalent to 20 deg, peak-to-peak). These combinations are elicited at 0.15, 0.3, and 0.6 Hz for evaluating the effect of motion frequency on tilt-translation ambiguity. In both devices, a closed-loop nulling task is also performed during pseudorandom motion with and without vibrotactile feedback of tilt. All tests are performed in complete darkness. PRELIMINARY RESULTS. Data collection is currently ongoing. Results to date suggest there is a trend for translation motion perception to be increased at the low and medium frequencies on landing day compared to pre-flight. Manual control performance is improved with vibrotactile feedback. DISCUSSION. The results of this study indicate that post-flight recovery of motion perception and manual control performance is complete within 8 days following short-duration space missions. Vibrotactile feedback of tilt improves manual control performance both before and after flight.

  6. Motion Perception and Manual Control Performance During Passive Tilt and Translation Following Space Flight

    NASA Technical Reports Server (NTRS)

    Clement, Gilles; Wood, Scott J.

    2010-01-01

    This joint ESA-NASA study is examining changes in motion perception following Space Shuttle flights and the operational implications of post-flight tilt-translation ambiguity for manual control performance. Vibrotactile feedback of tilt orientation is also being evaluated as a countermeasure to improve performance during a closed-loop nulling task. METHODS. Data has been collected on 5 astronaut subjects during 3 preflight sessions and during the first 8 days after Shuttle landings. Variable radius centrifugation (216 deg/s) combined with body translation (12-22 cm, peak-to-peak) is utilized to elicit roll-tilt perception (equivalent to 20 deg, peak-to-peak). A forward-backward moving sled (24-390 cm, peak-to-peak) with or without chair tilting in pitch is utilized to elicit pitch tilt perception (equivalent to 20 deg, peak-to-peak). These combinations are elicited at 0.15, 0.3, and 0.6 Hz for evaluating the effect of motion frequency on tilt-translation ambiguity. In both devices, a closed-loop nulling task is also performed during pseudorandom motion with and without vibrotactile feedback of tilt. All tests are performed in complete darkness. PRELIMINARY RESULTS. Data collection is currently ongoing. Results to date suggest there is a trend for translation motion perception to be increased at the low and medium frequencies on landing day compared to pre-flight. Manual control performance is improved with vibrotactile feedback. DISCUSSION. The results of this study indicate that post-flight recovery of motion perception and manual control performance is complete within 8 days following short-duration space missions. Vibrotactile feedback of tilt improves manual control performance both before and after flight.

  7. Real-time high-speed motion blur compensation system based on back-and-forth motion control of galvanometer mirror.

    PubMed

    Hayakawa, Tomohiko; Watanabe, Takanoshin; Ishikawa, Masatoshi

    2015-12-14

    We developed a novel real-time motion blur compensation system for the blur caused by high-speed one-dimensional motion between a camera and a target. The system consists of a galvanometer mirror and a high-speed color camera, without the need for any additional sensors. We controlled the galvanometer mirror with continuous back-and-forth oscillating motion synchronized to a high-speed camera. The angular speed of the mirror is given in real time within 10 ms based on the concept of background tracking and rapid raw Bayer block matching. Experiments demonstrated that our system captures motion-invariant images of objects moving at speeds up to 30 km/h.

  8. A Motion Control Method of Multi-joint Robots Utilizing Stiffness Adaptation for Energy Saving

    NASA Astrophysics Data System (ADS)

    Uemura, Mitsunori; Kawamura, Sadao

    This paper investigates a new motion control method of multi-joint robots utilizing stiffness adjustment of mechanical elastic elements for the purpose of energy saving. This control method is designed to realize a condition similar to resonance of linear systems by the stiffness adjustment, even though the controlled systems have nonlinear dynamics and multi degree-of-freedom. The control method has two control objectives. One is to realize trajectory tracking control. The other is to reduce actuator torque as much as possible by the stiffness adjustment. This controller does not require exact parameter values of the controlled systems. Some fundamental parts of stability analysis and an energy saving effect are discussed mathematically. Some simulation results demonstrate the effectiveness of the proposed control method.

  9. Artificial magnetotactic motion control of Tetrahymena pyriformis using ferromagnetic nanoparticles: A tool for fabrication of microbiorobots

    NASA Astrophysics Data System (ADS)

    Kim, Dal Hyung; Cheang, U. Kei; Kőhidai, László; Byun, Doyoung; Kim, Min Jun

    2010-10-01

    We induce artificial magnetotaxis in Tetrahymena pyriformis, a eukaryotic ciliate, using ferro-magnetic nanoparticles and an external time-varying magnetic field. Magnetizing internalized iron oxide particles (magnetite), allows control of the swimming direction of an individual cell using two sets of electromagnets. Real-time feedback control was performed with a vision tracking system, which demonstrated controllability of a single cell. Since the endogenous motility of the cell is combined in one system with artificial magnetotaxis, the motion of artificially magnetotactic T. pyriformis is finely controllable. Thus, artificially magnetotactic T. pyriformis is a promising candidate microrobot for microassembly and transport in microfluidic environments.

  10. Control of humanoid robot via motion-onset visual evoked potentials

    PubMed Central

    Li, Wei; Li, Mengfan; Zhao, Jing

    2015-01-01

    This paper investigates controlling humanoid robot behavior via motion-onset specific N200 potentials. In this study, N200 potentials are induced by moving a blue bar through robot images intuitively representing robot behaviors to be controlled with mind. We present the individual impact of each subject on N200 potentials and discuss how to deal with individuality to obtain a high accuracy. The study results document the off-line average accuracy of 93% for hitting targets across over five subjects, so we use this major component of the motion-onset visual evoked potential (mVEP) to code people's mental activities and to perform two types of on-line operation tasks: navigating a humanoid robot in an office environment with an obstacle and picking-up an object. We discuss the factors that affect the on-line control success rate and the total time for completing an on-line operation task. PMID:25620918

  11. Imparting Motion to a Test Object Such as a Motor Vehicle in a Controlled Fashion

    NASA Technical Reports Server (NTRS)

    Southward, Stephen C. (Inventor); Reubush, Chandler (Inventor); Pittman, Bryan (Inventor); Roehrig, Kurt (Inventor); Gerard, Doug (Inventor)

    2014-01-01

    An apparatus imparts motion to a test object such as a motor vehicle in a controlled fashion. A base has mounted on it a linear electromagnetic motor having a first end and a second end, the first end being connected to the base. A pneumatic cylinder and piston combination have a first end and a second end, the first end connected to the base so that the pneumatic cylinder and piston combination is generally parallel with the linear electromagnetic motor. The second ends of the linear electromagnetic motor and pneumatic cylinder and piston combination being commonly linked to a mount for the test object. A control system for the linear electromagnetic motor and pneumatic cylinder and piston combination drives the pneumatic cylinder and piston combination to support a substantial static load of the test object and the linear electromagnetic motor to impart controlled motion to the test object.

  12. Control of humanoid robot via motion-onset visual evoked potentials.

    PubMed

    Li, Wei; Li, Mengfan; Zhao, Jing

    2014-01-01

    This paper investigates controlling humanoid robot behavior via motion-onset specific N200 potentials. In this study, N200 potentials are induced by moving a blue bar through robot images intuitively representing robot behaviors to be controlled with mind. We present the individual impact of each subject on N200 potentials and discuss how to deal with individuality to obtain a high accuracy. The study results document the off-line average accuracy of 93% for hitting targets across over five subjects, so we use this major component of the motion-onset visual evoked potential (mVEP) to code people's mental activities and to perform two types of on-line operation tasks: navigating a humanoid robot in an office environment with an obstacle and picking-up an object. We discuss the factors that affect the on-line control success rate and the total time for completing an on-line operation task.

  13. Focused Ultrasound Surgery Control Using Local Harmonic Motion: VX2 Tumor Study

    NASA Astrophysics Data System (ADS)

    Curiel, Laura; Chopra, Rajiv; Goertz, David; Hynynen, Kullervo

    2009-04-01

    The objective of this study was to develop a real-time method for controlling focused ultrasound surgery using ultrasound imaging. The approach uses measurements of localized harmonic motion (LHM) in order to perform controlled FUS exposures by detecting changes in the elastic properties of tissues during coagulation. Methods: Nine New Zealand rabbits with VX2 tumors implanted in the thigh were used for this study. LHM was generated within the tumors by periodic induction of radiation force using a FUS transducer (80-mm focal length, 100-mm diameter, 20-mm central hole, 1.485-MHz). Tissue motion was tracked by collecting and cross-correlating RF signals during the motion using a separate diagnostic transducer (3-kHz PRF, 5-MHz). After locating the tumor in MR images, a series of sonications were performed to treat the tumors using a reduction in LHM amplitude to control the exposure. Results: LHM was successfully used to control the sonications. A LHM amplitude threshold value was determined at which changes were considered significant and then the exposure was started and stopped when the LHM amplitude dropped below the threshold. The appearance of a lesion was then verified by MRI. The feasibility of LHM measurements to control FUS exposure was validated.

  14. Applications of DNA Nanomechanical Devices to Molecular Biology and to Programmed Dynamic Motion

    NASA Astrophysics Data System (ADS)

    Liu, Chunhua

    Not merely is DNA a favorable genetic material, but an effective supermolecular subunit for nanoconstruction as well. In structural DNA nanotechnology, rigid branched DNA motifs have been combined with sticky-ended cohesion to build DNA objects, arrays and devices for functional purposes. Reciprocating devices are key features in macroscopic machines. In Chapter II, I report the construction of two reciprocal PX-JX2 devices, wherein the control strands leading to the PX state in one device lead to the JX2 state in the other device, and vice versa. The formation, transformation and reciprocal motions of these two devices are confirmed utilizing gel electrophoresis, and atomic force microscopy. This system is likely to be of use for molecular robotic applications where reciprocal motions are of value in addition its inherent contribution to molecular choreography and molecular aesthetics. Recently, several DNA-based nanomechanical devices have been developed as an attractive tool for fine measurements on nanoscale objects. In Chapter III, I have constructed a device wherein two DNA triple crossover (TX) molecules are connected by a shaft, similar to a previous device that measured the amount of work that can be performed by integration host factor [Shen, W., Bruist, M., Goodman, S. & Seeman, N. C., Angew. Chemie Int. Ed. 43, 4750-4752 (2004)]. In the present case, the binding site on the shaft contains the sequence recognized by apo-SoxR, the apo-form of a protein that is a redox-sensing transcriptional activator; previous data suggest that it distorts its binding site by an amount that corresponds to about two base pairs. A pair of dyes reports the fluorescence resonance energy transfer (FRET) signal between the two TX domains, reflecting changes in the shape of the device upon binding the protein. The TX domains are used to amplify the signal expected from a relatively small distortion of the DNA binding site. From FRET analysis of apo-SoxR binding, the effect of

  15. When brain damage "improves" perception: neglect patients can localize motion-shifted probes better than controls.

    PubMed

    de Vito, Stefania; Lunven, Marine; Bourlon, Clémence; Duret, Christophe; Cavanagh, Patrick; Bartolomeo, Paolo

    2015-12-01

    When we look at bars flashed against a moving background, we see them displaced in the direction of the upcoming motion (flash-grab illusion). It is still debated whether these motion-induced position shifts are low-level, reflexive consequences of stimulus motion or high-level compensation engaged only when the stimulus is tracked with attention. To investigate whether attention is a causal factor for this striking illusory position shift, we evaluated the flash-grab illusion in six patients with damaged attentional networks in the right hemisphere and signs of left visual neglect and six age-matched controls. With stimuli in the top, right, and bottom visual fields, neglect patients experienced the same amount of illusion as controls. However, patients showed no significant shift when the test was presented in their left hemifield, despite having equally precise judgments. Thus, paradoxically, neglect patients perceived the position of the flash more veridically in their neglected hemifield. These results suggest that impaired attentional processes can reduce the interaction between a moving background and a superimposed stationary flash, and indicate that attention is a critical factor in generating the illusory motion-induced shifts of location.

  16. Direction discrimination thresholds in binocular, monocular, and dichoptic viewing: Motion opponency and contrast gain control.

    PubMed

    Maehara, Goro; Hess, Robert F; Georgeson, Mark A

    2017-01-01

    We studied the binocular organization of motion opponency and its relationship to contrast gain control. Luminance contrast thresholds for discriminating direction of motion were measured for drifting Gabor patterns (target) presented on counterphase flickering Gabor patterns (pedestal). There were four presentation conditions: binocular, monocular, dichoptic, and half-binocular. For the half-binocular presentation, the target was presented to one eye while pedestals were presented to both eyes. In addition, to test for motion opponency, we studied two increment and decrement conditions, in which the target increased contrast for one direction of movement but decreased it for the opposite moving component of the pedestal. Threshold versus pedestal contrast functions showed a dipper shape, and there was a strong interaction between pedestal contrast and test condition. Binocular thresholds were lower than monocular thresholds but only at low pedestal contrasts. Monocular and half-binocular thresholds were similar at low pedestal contrasts, but half-binocular thresholds became higher and closer to dichoptic thresholds as pedestal contrast increased. Adding the decremental target reduced thresholds by a factor of two or more-a strong sign of opponency-when the decrement was in the same eye as the increment or the opposite eye. We compared several computational models fitted to the data. Converging evidence from the present and previous studies (Gorea, Conway, & Blake, 2001) suggests that motion opponency is most likely to be monocular, occurring before direction-specific binocular summation and before divisive, binocular gain control.

  17. Quality control procedures for dynamic treatment delivery techniques involving couch motion.

    PubMed

    Yu, Victoria Y; Fahimian, Benjamin P; Xing, Lei; Hristov, Dimitre H

    2014-08-01

    In this study, the authors introduce and demonstrate quality control procedures for evaluating the geometric and dosimetric fidelity of dynamic treatment delivery techniques involving treatment couch motion synchronous with gantry and multileaf collimator (MLC). Tests were designed to evaluate positional accuracy, velocity constancy and accuracy for dynamic couch motion under a realistic weight load. A test evaluating the geometric accuracy of the system in delivering treatments over complex dynamic trajectories was also devised. Custom XML scripts that control the Varian TrueBeam™ STx (Serial #3) axes in Developer Mode were written to implement the delivery sequences for the tests. Delivered dose patterns were captured with radiographic film or the electronic portal imaging device. The couch translational accuracy in dynamic treatment mode was 0.01 cm. Rotational accuracy was within 0.3°, with 0.04 cm displacement of the rotational axis. Dose intensity profiles capturing the velocity constancy and accuracy for translations and rotation exhibited standard deviation and maximum deviations below 3%. For complex delivery involving MLC and couch motions, the overall translational accuracy for reproducing programmed patterns was within 0.06 cm. The authors conclude that in Developer Mode, TrueBeam™ is capable of delivering dynamic treatment delivery techniques involving couch motion with good geometric and dosimetric fidelity.

  18. Modeling, system identification, and control for slosh-free motion of an open container of liquid

    SciTech Connect

    Feddema, J.; Baty, R.; Dykhuizen, R.; Dohrmann, C.; Parker, G.; Robinett, R.; Romero, V.; Schmitt, D.

    1996-04-01

    This report discusses work performed under a Cooperative Research And Development Agreement (CRADA) with Corning, Inc., to analyze and test various techniques for controlling the motion of a high speed robotic arm carrying an open container of viscous liquid, in this case, molten glass. A computer model was generated to estimate the modes of oscillation of the liquid based on the shape of the container and the viscosity of the liquid. This fluid model was experimentally verified and tuned based on experimental data from a capacitive sensor on the side of the container. A model of the robot dynamics was also developed and verified through experimental tests on a Fanuc S-800 robot arm. These two models were used to estimate the overall modes of oscillation of an open container of liquid being carried by a robot arm. Using the estimated modes, inverse dynamic control techniques were used to determine a motion profile which would eliminate waves on the liquid`s surface. Experimental tests showed that residual surface waves in an open container of water at the end of motion were reduced by over 95% and that in-motion surface waves were reduced by over 75%.

  19. The influence of range of motion versus application of force on vertical jump performance in prepubescent girls and adult females.

    PubMed

    Floría, Pablo; Harrison, Andrew J

    2014-01-01

    This study examined whether during childhood, the parameters for the range of motion had more influence on vertical jump height than parameters for application of force. Counter-movement jumps performed by 36 girls aged between 5 and 8 years and 20 adult females were examined using force platform analysis. Multiple regression analysis of the data indicated that the parameters for the range of motion had more influence on jump height than the parameters for application of force. This was demonstrated by standardised coefficients for range of motion which were higher than the standardised coefficients for application of force. Although this trend was observed in both groups, the influence of the range of motion was relatively greater in prepubescent girls than in adult females. The present results suggest that prepubescent girls increased their jump height by increasing the range of motion over which force is applied.

  20. Micropositioning and Control of an Underactuated Platform for Microscopic Applications.

    PubMed

    Park, Kihan; Desai, Jaydev P

    2016-12-01

    For automation of biological experiments at the micro-scale, highly precise manipulator equipped with a microscope is required. However, current micropositioning stages have several limitations, such as: 1) manual operation, 2) lack of rotational capability, 3) incompatibility with a microscope, and 4) small range of motion (RoM). This research aims to develop a microscope compatible XYθ micropositioning stage with large RoM for phenotyping multiple biological samples rapidly for various microscopic applications. An underactuated planar mechanism, kinematic analysis, and control of the XYθ stage are presented in this paper. The planar mechanism consists of two piezoelectric linear actuators for translational motion capability and two passive revolute joints at the tip of each linear actuator for rotational capability. Based on the kinematic analysis of the stage, controllability and control strategy of the underactuated stage is described. Finally, the feasibility of the micropositioning stage for a general positioning and orienting task is verified by both simulation and tissue core experiments.

  1. Folded Elastic Strip-Based Triboelectric Nanogenerator for Harvesting Human Motion Energy for Multiple Applications.

    PubMed

    Kang, Yue; Wang, Bo; Dai, Shuge; Liu, Guanlin; Pu, Yanping; Hu, Chenguo

    2015-09-16

    A folded elastic strip-based triboelectric nanogenerator (FS-TENG) made from two folded double-layer elastic strips of Al/PET and PTFE/PET can achieve multiple functions by low frequency mechanical motion. A single FS-TENG with strip width of 3 cm and length of 27 cm can generate a maximum output current, open-circuit voltage, and peak power of 55 μA, 840 V, and 7.33 mW at deformation frequency of 4 Hz with amplitude of 2.5 cm, respectively. This FS-TENG can work as a weight sensor due to its good elasticity. An integrated generator assembled by four FS-TENGs (IFS-TENG) can harvest the energy of human motion like flapping hands and walking steps. In addition, the IFS-TENG combined with electromagnetically induced electricity can achieve a completely self-driven doorbell with flashing lights. Moreover, a box-like generator integrated by four IFS-TENGs inside can work in horizontal or random motion modes and can be improved to harvest energy in all directions. This work promotes the research of completely self-driven systems and energy harvesting of human motion for applications in our daily life.

  2. Shallow and deep controls on lava lake surface motion at Kīlauea Volcano

    NASA Astrophysics Data System (ADS)

    Patrick, M. R.; Orr, T.; Swanson, D. A.; Lev, E.

    2016-12-01

    Lava lakes provide a rare window into magmatic behavior, and lake surface motion has been used to infer deeper properties of the magmatic system. At Halema'uma'u Crater, at the summit of Kīlauea Volcano, multidisciplinary observations for the past several years indicate that lava lake surface motion can be broadly divided into two regimes: 1) stable and 2) unstable. Stable behavior is driven by lava upwelling from deeper in the lake (presumably directly from the conduit) and is an intrinsic process that drives lava lake surface motion most of the time. This stable behavior can be interrupted by periods of unstable flow (often reversals) driven by spattering - a shallowly-rooted process often extrinsically triggered by small rockfalls from the crater wall. The bursting bubbles at spatter sources create void spaces and a localized surface depression which draws and consumes surrounding surface crust. Spattering is therefore a location of lava downwelling, not upwelling. Stable (i.e. deep, upwelling-driven) and unstable (i.e. shallow, spattering-driven) behavior often alternate through time, have characteristic surface velocities, flow directions and surface temperature regimes, and also correspond to changes in spattering intensity, outgassing rates, lava level and seismic tremor. These results highlight that several processes, originating at different depths, can control the motion of the lava lake surface, and long-term interdisciplinary monitoring is required to separate these influences. These observations indicate that lake surface motion is not always a reliable proxy for deeper lake or magmatic processes. From these observations, we suggest that shallow outgassing (spattering), not lake convection, drives the variations in lake motion reported at Erta 'Ale lava lake.

  3. Virtual reality-based assessment of basic laparoscopic skills using the Leap Motion controller.

    PubMed

    Lahanas, Vasileios; Loukas, Constantinos; Georgiou, Konstantinos; Lababidi, Hani; Al-Jaroudi, Dania

    2017-05-02

    The majority of the current surgical simulators employ specialized sensory equipment for instrument tracking. The Leap Motion controller is a new device able to track linear objects with sub-millimeter accuracy. The aim of this study was to investigate the potential of a virtual reality (VR) simulator for assessment of basic laparoscopic skills, based on the low-cost Leap Motion controller. A simple interface was constructed to simulate the insertion point of the instruments into the abdominal cavity. The controller provided information about the position and orientation of the instruments. Custom tools were constructed to simulate the laparoscopic setup. Three basic VR tasks were developed: camera navigation (CN), instrument navigation (IN), and bimanual operation (BO). The experiments were carried out in two simulation centers: MPLSC (Athens, Greece) and CRESENT (Riyadh, Kingdom of Saudi Arabia). Two groups of surgeons (28 experts and 21 novices) participated in the study by performing the VR tasks. Skills assessment metrics included time, pathlength, and two task-specific errors. The face validity of the training scenarios was also investigated via a questionnaire completed by the participants. Expert surgeons significantly outperformed novices in all assessment metrics for IN and BO (p < 0.05). For CN, a significant difference was found in one error metric (p < 0.05). The greatest difference between the performances of the two groups occurred for BO. Qualitative analysis of the instrument trajectory revealed that experts performed more delicate movements compared to novices. Subjects' ratings on the feedback questionnaire highlighted the training value of the system. This study provides evidence regarding the potential use of the Leap Motion controller for assessment of basic laparoscopic skills. The proposed system allowed the evaluation of dexterity of the hand movements. Future work will involve comparison studies with validated simulators and

  4. Brownian motion

    NASA Astrophysics Data System (ADS)

    Lavenda, B. H.

    1985-02-01

    Brownian motion, the doubly random motion of small particles suspended in a liquid due to molecular collisions, and its implications and applications in the history of modern science are discussed. Topics examined include probabilistic phenomena, the kinetic theory of gases, Einstein's atomic theory of Brownian motion, particle displacement, diffusion measurements, the determination of the mass of the atom and of Avogadro's number, the statistical mechanics of thermodynamics, nonequilibrium systems, Langevin's equation of motion, time-reversed evolution, mathematical analogies, and applications in economics and radio navigation. Diagrams and drawings are provided.

  5. Low Thrust Relative Motion Control of Satellite Formations in Deep Space

    NASA Astrophysics Data System (ADS)

    Prioroc, Claudiu-Lucian; Mikkola, Seppo

    The problem of placing and controlling a formation of satellites on a Halo orbit is studied. The Earth-Sun circular restricted three body problem is considered. A family of artificial Halo orbits with the same periods, around the L 1 and L 2 Lagrange points in the Earth-Sun system is found using the pseudo-arc-length continuation method. The orbits are used are reference trajectories for satellites to track. The problem of orbit stability, bounding and controlling the relative motion by means of nonlinear control is addressed.

  6. Input-Shaped Link Motion Control of Planar Space Robot Equipped with Flexible Appendage

    NASA Astrophysics Data System (ADS)

    Kasai, Shinya; Kojima, Hirohisa

    Control of a space robot without actuators on the main body is an underactuated control problem. Various stabilization methods, such as the time-varying feedback control method, discontinuous feedback control method, center manifold-based method, zero-dynamics method and sliding-mode control method have been proposed. However, past studies have not considered underactuated space robots equipped with a flexible appendage, such as solar panels. If the manipulators are simply controlled to achieve the target state for the robot using the past controllers without taking a flexible appendage into consideration, residual vibration remains even after the link motion has finished. In order to suppress the residual vibration on the flexible appendage, we apply the input-shaping technique to the link motion of an underactuated planar space robot. Numerical and experimental studies are carried out to validate the proposed method for a planar dual-link space robot with a flexible appendage. The results show that the proposed method is capable of not only controlling the link angles and the main body attitude to the goal angles, but also suppressing the residual vibration on the flexible appendage.

  7. Correction of Motion Artifacts From Shuttle Mode Computed Tomography Acquisitions for Body Perfusion Imaging Applications.

    PubMed

    Ghosh, Payel; Chandler, Adam G; Altinmakas, Emre; Rong, John; Ng, Chaan S

    2016-01-01

    The aim of this study was to investigate the feasibility of shuttle-mode computed tomography (CT) technology for body perfusion applications by quantitatively assessing and correcting motion artifacts. Noncontrast shuttle-mode CT scans (10 phases, 2 nonoverlapping bed locations) were acquired from 4 patients on a GE 750HD CT scanner. Shuttling effects were quantified using Euclidean distances (between-phase and between-bed locations) of corresponding fiducial points on the shuttle and reference phase scans (prior to shuttle mode). Motion correction with nonrigid registration was evaluated using sum-of-squares differences and distances between centers of segmented volumes of interest on shuttle and references images. Fiducial point analysis showed an average shuttling motion of 0.85 ± 1.05 mm (between-bed) and 1.18 ± 1.46 mm (between-phase), respectively. The volume-of-interest analysis of the nonrigid registration results showed improved sum-of-squares differences from 2950 to 597, between-bed distance from 1.64 to 1.20 mm, and between-phase distance from 2.64 to 1.33 mm, respectively, averaged over all cases. Shuttling effects introduced during shuttle-mode CT acquisitions can be computationally corrected for body perfusion applications.

  8. Particle motion in unsteady two-dimensional peristaltic flow with application to the ureter

    NASA Astrophysics Data System (ADS)

    Jiménez-Lozano, Joel; Sen, Mihir; Dunn, Patrick F.

    2009-04-01

    Particle motion in an unsteady peristaltic fluid flow is analyzed. The fluid is incompressible and Newtonian in a two-dimensional planar geometry. A perturbation method based on a small ratio of wave height to wavelength is used to obtain a closed-form solution for the fluid velocity field. This analytical solution is used in conjunction with an equation of motion for a small rigid sphere in nonuniform flow taking Stokes drag, virtual mass, Faxén, Basset, and gravity forces into account. Fluid streamlines and velocity profiles are calculated. Theoretical values for pumping rates are compared with available experimental data. An application to ureteral peristaltic flow is considered since fluid flow in the ureter is sometimes accompanied by particles such as stones or bacteriuria. Particle trajectories for parameters that correspond to calcium oxalates for calculosis and Escherichia coli type for bacteria are analyzed. The findings show that retrograde or reflux motion of the particles is possible and bacterial transport can occur in the upper urinary tract when there is a partial occlusion of the wave. Dilute particle mixing is also investigated, and it is found that some of the particles participate in the formation of a recirculating bolus, and some of them are delayed in transit and eventually reach the walls. This can explain the failure of clearing residuals from the upper urinary tract calculi after successful extracorporeal shock wave lithotripsy. The results may also be relevant to the transport of other physiological fluids and industrial applications in which peristaltic pumping is used.

  9. Motion-base simulator results of advanced supersonic transport handling qualities with active controls

    NASA Technical Reports Server (NTRS)

    Feather, J. B.; Joshi, D. S.

    1981-01-01

    Handling qualities of the unaugmented advanced supersonic transport (AST) are deficient in the low-speed, landing approach regime. Consequently, improvement in handling with active control augmentation systems has been achieved using implicit model-following techniques. Extensive fixed-based simulator evaluations were used to validate these systems prior to tests with full motion and visual capabilities on a six-axis motion-base simulator (MBS). These tests compared the handling qualities of the unaugmented AST with several augmented configurations to ascertain the effectiveness of these systems. Cooper-Harper ratings, tracking errors, and control activity data from the MBS tests have been analyzed statistically. The results show the fully augmented AST handling qualities have been improved to an acceptable level.

  10. Motion compensated controller for a tendon-sheath-driven flexible endoscopic robot.

    PubMed

    Xu, Wenjun; Poon, Carmen C Y; Yam, Y; Chiu, P W Y

    2017-03-01

    A tendon-sheath system (TSS) has the advantages of being relatively compact in size, flexible and low cost, and therefore is favoured in building flexible endoscopic robots to pass through long and tortuous human lumen. TSS, however, is prone to nonlinear behaviors such as backlash, hysteresis and direction dependent properties. A compensation technique is required to improve its positioning performance. Tension and elongation models of TSS are analyzed. A feedforward motion compensation controller is designed to compensate the asymmetric backlash behavior of the TSS in real time. Motion tracking experiments were conducted on a TSS driven two DOFs continuum manipulator. The results showed that using the proposed compensation methods, tracking error can be reduced by 74%. The proposed compensation method is useful for controlling flexible continuum robots, which are anticipated to have emerging roles in assisting surgeons to perform the increasingly technically challenging endoscopic procedures. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  11. Truss Climbing Robot for Space Station: Design, Analysis, and Motion Control

    NASA Astrophysics Data System (ADS)

    Chung, Wing Kwong

    The application of space robots has become more popular in performing tasks such as Intra and Extra Vehicular Activities (EVA) in Low Earth Orbit. For EVA, space robots were always designed as a chain-like manipulator with a joint configuration similar to on the earth robotic arm. Based on their joint configuration, they can be classified into two main categories. The first one is the six degrees of freedom (DOF) robotic arm including Shuttle Remote Manipulator System (SRMS), Engineering Test Satellite No. 7 (ETS-VII), the Main Arm (MA) and the Small Fine Arm (SFA) of Module Remote Manipulator System (JEMRMS). The other group is the seven-DOF space robotic arm which includes European Robotic Arm (ERA) and Space Station Remote Manipulator System (SSRMS), or Canadarm2. They not only perform manipulation tasks, but also be able to navigate on the exterior of the International Space Station (ISS). In a free floating environment, motions of a space robotic arm cause the attitude change of a space station because of their dynamic coupling effect. Hence, the stabilization of the space station attitude is important to maintain the electrical energy generated by the solar panels and the signal strength for communication. Most of research in this area focuses on the motion control of a space manipulator through the study of Generalized Jacobian Matrix. Little research has been conducted specifically on the design of locomotion mechanism of a space manipulator. This dissertation proposes a novel methodology for the locomotion on a space station which aims to lower the disturbance on a space station. Without modifying the joint configuration of conventional space manipulators, the use of a new gripping mechanism is proposed which combines the advantages of active wheels and conventional grippers. To realize the proposed gripping mechanism, this dissertation also presents the design of a novel frame climbing robot (Frambot) which is equipped with the new gripping mechanism

  12. Energy Consumption Analysis Procedure for Robotic Applications in different task motion

    NASA Astrophysics Data System (ADS)

    Ahmed, Iman; Aris, Ishak b.; Hamiruce Marhaban, Mohammad; Juraiza Ishak, Asnor

    2015-11-01

    This work proposes energy analysis method for humanoid robot, seen from simple motion task to complex one in energy chain. The research developed a procedure suitable for analysis, saving and modelling of energy consumption not only in this type of robot but also in most robots that based on electrical power as an energy source. This method has validated by an accurate integration using Matlab software for the power consumption curve to calculate the energy of individual and multiple servo motors. Therefore, this study can be considered as a procedure for energy analysis by utilizing the laboratory instruments capabilities to measure the energy parameters. We performed a various task motions with different angular speed to find out the speed limits in terms of robot stability and control strategy. A battery capacity investigation have been searched for several types of batteries to extract the power modelling equation and energy density parameter for each battery type, Matlab software have been built to design the algorithm and to evaluate experimental amount of the energy which is represented by area under the curve of the power curves. This will provide a robust estimation for the required energy in different task motions to be considered in energy saving (i.e., motion planning and real time scheduling).

  13. Development of virtual reality exercise of hand motion assist robot for rehabilitation therapy by patient self-motion control.

    PubMed

    Ueki, Satoshi; Nishimoto, Yutaka; Abe, Motoyuki; Kawasaki, Haruhisa; Ito, Satoshi; Ishigure, Yasuhiko; Mizumoto, Jun; Ojika, Takeo

    2008-01-01

    This paper presents a virtual reality-enhanced hand rehabilitation support system with a symmetric master-slave motion assistant for independent rehabilitation therapies. Our aim is to provide fine motion exercise for a hand and fingers, which allows the impaired hand of a patient to be driven by his or her healthy hand on the opposite side. Since most disabilities caused by cerebral vascular accidents or bone fractures are hemiplegic, we adopted a symmetric master-slave motion assistant system in which the impaired hand is driven by the healthy hand on the opposite side. A VR environment displaying an effective exercise was created in consideration of system's characteristic. To verify the effectiveness of this system, a clinical test was executed by applying to six patients.

  14. An EMG Interface for the Control of Motion and Compliance of a Supernumerary Robotic Finger

    PubMed Central

    Hussain, Irfan; Spagnoletti, Giovanni; Salvietti, Gionata; Prattichizzo, Domenico

    2016-01-01

    In this paper, we propose a novel electromyographic (EMG) control interface to control motion and joints compliance of a supernumerary robotic finger. The supernumerary robotic fingers are a recently introduced class of wearable robotics that provides users additional robotic limbs in order to compensate or augment the existing abilities of natural limbs without substituting them. Since supernumerary robotic fingers are supposed to closely interact and perform actions in synergy with the human limbs, the control principles of extra finger should have similar behavior as human’s ones including the ability of regulating the compliance. So that, it is important to propose a control interface and to consider the actuators and sensing capabilities of the robotic extra finger compatible to implement stiffness regulation control techniques. We propose EMG interface and a control approach to regulate the compliance of the device through servo actuators. In particular, we use a commercial EMG armband for gesture recognition to be associated with the motion control of the robotic device and surface one channel EMG electrodes interface to regulate the compliance of the robotic device. We also present an updated version of a robotic extra finger where the adduction/abduction motion is realized through ball bearing and spur gears mechanism. We have validated the proposed interface with two sets of experiments related to compensation and augmentation. In the first set of experiments, different bimanual tasks have been performed with the help of the robotic device and simulating a paretic hand since this novel wearable system can be used to compensate the missing grasping abilities in chronic stroke patients. In the second set, the robotic extra finger is used to enlarge the workspace and manipulation capability of healthy hands. In both sets, the same EMG control interface has been used. The obtained results demonstrate that the proposed control interface is intuitive and can

  15. An EMG Interface for the Control of Motion and Compliance of a Supernumerary Robotic Finger.

    PubMed

    Hussain, Irfan; Spagnoletti, Giovanni; Salvietti, Gionata; Prattichizzo, Domenico

    2016-01-01

    In this paper, we propose a novel electromyographic (EMG) control interface to control motion and joints compliance of a supernumerary robotic finger. The supernumerary robotic fingers are a recently introduced class of wearable robotics that provides users additional robotic limbs in order to compensate or augment the existing abilities of natural limbs without substituting them. Since supernumerary robotic fingers are supposed to closely interact and perform actions in synergy with the human limbs, the control principles of extra finger should have similar behavior as human's ones including the ability of regulating the compliance. So that, it is important to propose a control interface and to consider the actuators and sensing capabilities of the robotic extra finger compatible to implement stiffness regulation control techniques. We propose EMG interface and a control approach to regulate the compliance of the device through servo actuators. In particular, we use a commercial EMG armband for gesture recognition to be associated with the motion control of the robotic device and surface one channel EMG electrodes interface to regulate the compliance of the robotic device. We also present an updated version of a robotic extra finger where the adduction/abduction motion is realized through ball bearing and spur gears mechanism. We have validated the proposed interface with two sets of experiments related to compensation and augmentation. In the first set of experiments, different bimanual tasks have been performed with the help of the robotic device and simulating a paretic hand since this novel wearable system can be used to compensate the missing grasping abilities in chronic stroke patients. In the second set, the robotic extra finger is used to enlarge the workspace and manipulation capability of healthy hands. In both sets, the same EMG control interface has been used. The obtained results demonstrate that the proposed control interface is intuitive and can

  16. Quaternion regularization and trajectory motion control in celestial mechanics and astrodynamics: II

    NASA Astrophysics Data System (ADS)

    Chelnokov, Yu. N.

    2014-07-01

    Problems of regularization in celestial mechanics and astrodynamics are considered, and basic regular quaternion models for celestial mechanics and astrodynamics are presented. It is shown that the effectiveness of analytical studies and numerical solutions to boundary value problems of controlling the trajectory motion of spacecraft can be improved by using quaternion models of astrodynamics. In this second part of the paper, specific singularity-type features (division by zero) are considered. They result from using classical equations in angular variables (particularly in Euler variables) in celestial mechanics and astrodynamics and can be eliminated by using Euler (Rodrigues-Hamilton) parameters and Hamilton quaternions. Basic regular (in the above sense) quaternion models of celestial mechanics and astrodynamics are considered; these include equations of trajectory motion written in nonholonomic, orbital, and ideal moving trihedrals whose rotational motions are described by Euler parameters and quaternions of turn; and quaternion equations of instantaneous orbit orientation of a celestial body (spacecraft). New quaternion regular equations are derived for the perturbed three-dimensional two-body problem (spacecraft trajectory motion). These equations are constructed using ideal rectangular Hansen coordinates and quaternion variables, and they have additional advantages over those known for regular Kustaanheimo-Stiefel equations.

  17. A kinetic equation for linear stable fractional motion with applications to space plasma physics

    SciTech Connect

    Watkins, Nicholas W; Credgington, Daniel; Sanchez, Raul; Rosenberg, SJ; Chapman, Sandra C

    2009-01-01

    Levy flights and fractional Brownian motion have become exemplars of the heavy-tailed jumps and long-ranged memory widely seen in physics. Natural time series frequently combine both effects, and linear fractional stable motion (lfsm) is a model process of this type, combining {alpha}-stable jumps with a memory kernel. In contrast complex physical spatiotemporal diffusion processes where both the above effects compete have for many years been modeled using the fully fractional kinetic equation for the continuous-time random walk (CTRW), with power laws in the probability density functions of both jump size and waiting time. We derive the analogous kinetic equation for lfsm and show that it has a diffusion coefficient with a power law in time rather than having a fractional time derivative like the CTRW. We discuss some preliminary results on the scaling of burst 'sizes' and 'durations' in lfsm time series, with applications to modeling existing observations in space physics and elsewhere.

  18. Results and applications of a space suit range-of-motion study

    NASA Technical Reports Server (NTRS)

    Reinhardt, AL

    1989-01-01

    The range of motion of space suits has traditionally been described using limited 2-D mapping of limb, torso, or arm movements performed in front of an orthogonal grid. A new technique for recovering extra-vehicular (EVA) space suit range-of-motion data during underwater testing was described in a paper presented by the author at the 1988 conference. The new technique uses digitized data which is automatically acquired from video images of the subject. Three-dimensional trajectories are recovered from these data, and can be displayed using 2-D computer graphics. Results of using this technique for the current shuttle EVA suit during underwater simulated weightlessness testing are discussed. Application of the data for use in animating anthropometric computer models is highlighted.

  19. Results and applications of a space suit range-of-motion study

    NASA Technical Reports Server (NTRS)

    Reinhardt, AL

    1989-01-01

    The range of motion of space suits has traditionally been described using limited 2-D mapping of limb, torso, or arm movements performed in front of an orthogonal grid. A new technique for recovering extra-vehicular (EVA) space suit range-of-motion data during underwater testing was described in a paper presented by the author at the 1988 conference. The new technique uses digitized data which is automatically acquired from video images of the subject. Three-dimensional trajectories are recovered from these data, and can be displayed using 2-D computer graphics. Results of using this technique for the current shuttle EVA suit during underwater simulated weightlessness testing are discussed. Application of the data for use in animating anthropometric computer models is highlighted.

  20. Effect of motion control running shoes compared with neutral shoes on tibial rotation during running.

    PubMed

    Rose, Alice; Birch, Ivan; Kuisma, Raija

    2011-09-01

    To determine whether a motion control running shoe reduces tibial rotation in the transverse plane during treadmill running. An experimental study measuring tibial rotation in volunteer participants using a repeated measures design. Human Movement Laboratory, School of Health Professions, University of Brighton. Twenty-four healthy participants were tested. The group comprised males and females with size 6, 7, 9 and 11 feet. The age range for participants was 19 to 31 years. The total range of proximal tibial rotation was measured using the Codamotion 3-D Movement Analysis System. A one-tailed paired t-test indicated a statistically significant decrease in the total range of proximal tibial rotation when a motion control shoe was worn (mean difference 1.38°, 95% confidence interval 0.03 to 2.73, P=0.04). There is a difference in tibial rotation in the transverse plane between a motion control running shoe and a neutral running shoe. The results from this study have implications for the use of supportive running shoes as a form of injury prevention. Copyright © 2010 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

  1. Highly stretchable and wearable graphene strain sensors with controllable sensitivity for human motion monitoring.

    PubMed

    Park, Jung Jin; Hyun, Woo Jin; Mun, Sung Cik; Park, Yong Tae; Park, O Ok

    2015-03-25

    Because of their outstanding electrical and mechanical properties, graphene strain sensors have attracted extensive attention for electronic applications in virtual reality, robotics, medical diagnostics, and healthcare. Although several strain sensors based on graphene have been reported, the stretchability and sensitivity of these sensors remain limited, and also there is a pressing need to develop a practical fabrication process. This paper reports the fabrication and characterization of new types of graphene strain sensors based on stretchable yarns. Highly stretchable, sensitive, and wearable sensors are realized by a layer-by-layer assembly method that is simple, low-cost, scalable, and solution-processable. Because of the yarn structures, these sensors exhibit high stretchability (up to 150%) and versatility, and can detect both large- and small-scale human motions. For this study, wearable electronics are fabricated with implanted sensors that can monitor diverse human motions, including joint movement, phonation, swallowing, and breathing.

  2. Application of Sampling Based Model Predictive Control to an Autonomous Underwater Vehicle

    DTIC Science & Technology

    2010-07-01

    55 Application of Sampling Based Model Predictive Control to an Autonomous Underwater Vehicle Unmanned Underwater Vehicles (UUVs) can be utilized...the vehicle can feasibly traverse. As a result, Sampling- Based Model Predictive Control (SBMPC) is proposed to simultaneously generate control...inputs and system trajectories for an autonomous underwater vehicle (AUV). The algorithm combines the benefits of sampling- based motion planning with

  3. Utility of the iPhone 4 Gyroscope Application in the Measurement of Wrist Motion.

    PubMed

    Lendner, Nuphar; Wells, Erik; Lavi, Idit; Kwok, Yan Yan; Ho, Pak-Cheong; Wollstein, Ronit

    2017-09-01

    Measurement of wrist range of motion (ROM) is important to all aspects of treatment and rehabilitation of upper extremity conditions. Recently, gyroscopes have been used to measure ROM and may be more precise than manual evaluations. The purpose of this study was to evaluate the use of the iPhone gyroscope application and compare it with use of a goniometer, specifically evaluating its accuracy and ease of use. A cross-sectional study evaluated adult Caucasian participants, with no evidence of wrist pathology. Wrist ROM measurements in 306 wrists using the 2 methods were compared. Demographic information was collected including age, sex, and occupation. Analysis included mixed models and Bland-Altman plots. Wrist motion was similar between the 2 methods. Technical difficulties were encountered with gyroscope use. Age was an independent predictor of ROM. Correct measurement of ROM is critical to guide, compare, and evaluate treatment and rehabilitation of the upper extremity. Inaccurate measurements could mislead the surgeon and harm patient adherence with therapy or surgeon instruction. An application used by the patient could improve adherence but needs to be reliable and easy to use. Evaluation is necessary before utilization of such an application. This study supports revision of the application on the iPhone to improve ease of use.

  4. DLP technology application: 3D head tracking and motion correction in medical brain imaging

    NASA Astrophysics Data System (ADS)

    Olesen, Oline V.; Wilm, Jakob; Paulsen, Rasmus R.; Højgaard, Liselotte; Larsen, Rasmus

    2014-03-01

    In this paper we present a novel sensing system, robust Near-infrared Structured Light Scanning (NIRSL) for three-dimensional human model scanning application. Human model scanning due to its nature of various hair and dress appearance and body motion has long been a challenging task. Previous structured light scanning methods typically emitted visible coded light patterns onto static and opaque objects to establish correspondence between a projector and a camera for triangulation. In the success of these methods rely on scanning objects with proper reflective surface for visible light, such as plaster, light colored cloth. Whereas for human model scanning application, conventional methods suffer from low signal to noise ratio caused by low contrast of visible light over the human body. The proposed robust NIRSL, as implemented with the near infrared light, is capable of recovering those dark surfaces, such as hair, dark jeans and black shoes under visible illumination. Moreover, successful structured light scan relies on the assumption that the subject is static during scanning. Due to the nature of body motion, it is very time sensitive to keep this assumption in the case of human model scan. The proposed sensing system, by utilizing the new near-infrared capable high speed LightCrafter DLP projector, is robust to motion, provides accurate and high resolution three-dimensional point cloud, making our system more efficient and robust for human model reconstruction. Experimental results demonstrate that our system is effective and efficient to scan real human models with various dark hair, jeans and shoes, robust to human body motion and produces accurate and high resolution 3D point cloud.

  5. Accuracy and precision of smartphone applications and commercially available motion sensors in multiple sclerosis.

    PubMed

    Balto, Julia M; Kinnett-Hopkins, Dominique L; Motl, Robert W

    2016-01-01

    There is increased interest in the application of smartphone applications and wearable motion sensors among multiple sclerosis (MS) patients. This study examined the accuracy and precision of common smartphone applications and motion sensors for measuring steps taken by MS patients while walking on a treadmill. Forty-five MS patients (Expanded Disability Status Scale (EDSS) = 1.0-5.0) underwent two 500-step walking trials at comfortable walking speed on a treadmill. Participants wore five motion sensors: the Digi-Walker SW-200 pedometer (Yamax), the UP2 and UP Move (Jawbone), and the Flex and One (Fitbit). The smartphone applications were Health (Apple), Health Mate (Withings), and Moves (ProtoGeo Oy). The Fitbit One had the best absolute (mean = 490.6 steps, 95% confidence interval (CI) = 485.6-495.5 steps) and relative accuracy (1.9% error), and absolute (SD = 16.4) and relative precision (coefficient of variation (CV) = 0.0), for the first 500-step walking trial; this was repeated with the second trial. Relative accuracy was correlated with slower walking speed for the first (rs = -.53) and second (rs = -.53) trials. The results suggest that the waist-worn Fitbit One is the most precise and accurate sensor for measuring steps when walking on a treadmill, but future research is needed (testing the device across a broader range of disability, at different speeds, and in real-life walking conditions) before inclusion in clinical research and practice with MS patients.

  6. Accuracy and precision of smartphone applications and commercially available motion sensors in multiple sclerosis

    PubMed Central

    Balto, Julia M; Kinnett-Hopkins, Dominique L

    2016-01-01

    Background There is increased interest in the application of smartphone applications and wearable motion sensors among multiple sclerosis (MS) patients. Objective This study examined the accuracy and precision of common smartphone applications and motion sensors for measuring steps taken by MS patients while walking on a treadmill. Methods Forty-five MS patients (Expanded Disability Status Scale (EDSS) = 1.0–5.0) underwent two 500-step walking trials at comfortable walking speed on a treadmill. Participants wore five motion sensors: the Digi-Walker SW-200 pedometer (Yamax), the UP2 and UP Move (Jawbone), and the Flex and One (Fitbit). The smartphone applications were Health (Apple), Health Mate (Withings), and Moves (ProtoGeo Oy). Results The Fitbit One had the best absolute (mean = 490.6 steps, 95% confidence interval (CI) = 485.6–495.5 steps) and relative accuracy (1.9% error), and absolute (SD = 16.4) and relative precision (coefficient of variation (CV) = 0.0), for the first 500-step walking trial; this was repeated with the second trial. Relative accuracy was correlated with slower walking speed for the first (rs = −.53) and second (rs = −.53) trials. Conclusion The results suggest that the waist-worn Fitbit One is the most precise and accurate sensor for measuring steps when walking on a treadmill, but future research is needed (testing the device across a broader range of disability, at different speeds, and in real-life walking conditions) before inclusion in clinical research and practice with MS patients. PMID:28607720

  7. Feedback attitude sliding mode regulation control of spacecraft using arm motion

    NASA Astrophysics Data System (ADS)

    Shi, Ye; Liang, Bin; Xu, Dong; Wang, Xueqian; Xu, Wenfu

    2013-09-01

    The problem of spacecraft attitude regulation based on the reaction of arm motion has attracted extensive attentions from both engineering and academic fields. Most of the solutions of the manipulator’s motion tracking problem just achieve asymptotical stabilization performance, so that these controllers cannot realize precise attitude regulation because of the existence of non-holonomic constraints. Thus, sliding mode control algorithms are adopted to stabilize the tracking error with zero transient process. Due to the switching effects of the variable structure controller, once the tracking error reaches the designed hyper-plane, it will be restricted to this plane permanently even with the existence of external disturbances. Thus, precise attitude regulation can be achieved. Furthermore, taking the non-zero initial tracking errors and chattering phenomenon into consideration, saturation functions are used to replace sign functions to smooth the control torques. The relations between the upper bounds of tracking errors and the controller parameters are derived to reveal physical characteristic of the controller. Mathematical models of free-floating space manipulator are established and simulations are conducted in the end. The results show that the spacecraft’s attitude can be regulated to the position as desired by using the proposed algorithm, the steady state error is 0.000 2 rad. In addition, the joint tracking trajectory is smooth, the joint tracking errors converges to zero quickly with a satisfactory continuous joint control input. The proposed research provides a feasible solution for spacecraft attitude regulation by using arm motion, and improves the precision of the spacecraft attitude regulation.

  8. Constrained motion control of flexible robot manipulators based on recurrent neural networks.

    PubMed

    Tian, Lianfang; Wang, Jun; Mao, Zongyuan

    2004-06-01

    In this paper, a neural network approach is presented for the motion control of constrained flexible manipulators, where both the contact force everted by the flexible manipulator and the position of the end-effector contacting with a surface are controlled. The dynamic equations for vibration of flexible link and constrained force are derived. The developed control, scheme can adaptively estimate the underlying dynamics of the manipulator using recurrent neural networks (RNNs). Based on the error dynamics of a feedback controller, a learning rule for updating the connection weights of the adaptive RNN model is obtained. Local stability properties of the control system are discussed. Simulation results are elaborated on for both position and force trajectory tracking tasks in the presence of varying parameters and unknown dynamics, which show that the designed controller performs remarkably well.

  9. Suboptimal LQR-based spacecraft full motion control: Theory and experimentation

    NASA Astrophysics Data System (ADS)

    Guarnaccia, Leone; Bevilacqua, Riccardo; Pastorelli, Stefano P.

    2016-05-01

    This work introduces a real time suboptimal control algorithm for six-degree-of-freedom spacecraft maneuvering based on a State-Dependent-Algebraic-Riccati-Equation (SDARE) approach and real-time linearization of the equations of motion. The control strategy is sub-optimal since the gains of the linear quadratic regulator (LQR) are re-computed at each sample time. The cost function of the proposed controller has been compared with the one obtained via a general purpose optimal control software, showing, on average, an increase in control effort of approximately 15%, compensated by real-time implementability. Lastly, the paper presents experimental tests on a hardware-in-the-loop six-degree-of-freedom spacecraft simulator, designed for testing new guidance, navigation, and control algorithms for nano-satellites in a one-g laboratory environment. The tests show the real-time feasibility of the proposed approach.

  10. Real-time cooperating motion generation for man-machine systems and its application to medical technology.

    PubMed

    Seto, Fumi; Hirata, Yasuhisa; Kosuge, Kazuhiro

    2007-01-01

    In this paper, we propose a cooperating motion generation method for man-machine cooperation systems in which the machines are controlled based on the intentional force applied by a human/humans for realizing several tasks in cooperation with a human/humans. By applying this method, the systems could avoid self-collisions, collisions with obstacles and other dangerous situations during the tasks. Proposed method consists of two parts; representation method of robots' body referred to as "RoBE (Representation of Body by Elastic elements)", and cooperating motion generation method using RoBE. As the application examples of proposed method, we focused on robots cooperating with a human/humans and surgery robot tools from the aspect of medical and welfare field. We did the experiments using human-friendly robot, referred to as MR Helper, for illustrating the validity of the proposed method. We also did the computer simulation to indicate the prospects of applications of our self-collision avoidance method to surgery robot tools.

  11. Controlling Chaos of Magnetic-Domain-Wall Motion by using Delayed-Feedback-Control with Automatic Gain-Adjustment

    NASA Astrophysics Data System (ADS)

    Utsumi, Takuya; Okuno, Hikaru

    In this research, the chaotic motion of magnetic domain wall is controlled by using Delayed-Feedback-Control (DFC) with automatic gain-adjustment, modified by Nakajima and Ueda in 1995. The method of automatic gain-adjustment is newly applied to Extended-DFC (E-DFC) for more highly performance. It is clearly confirmed that the control-gain was automatically adjusted on each results. But, in this case, the response of E-DFC has not been improved. It is found that the delayed time has strongly influenced on the response. The selective E-DFC is proposed and the response was best.

  12. Cervical Motion Segment Percent Contributions to Flexion-Extension During Continuous Functional Movement in Control Subjects and Arthrodesis Patients

    PubMed Central

    Anderst, William J; Donaldson, William F; Lee, Joon Y; Kang, James D

    2013-01-01

    Study Design Case-control. Objective To precisely quantify and compare intervertebral segmental contributions to cervical spine flexion-extension during continuous, functional flexion-extension in asymptomatic subjects to single-level anterior arthrodesis patients. Summary of Background Data Segmental contributions to cervical flexion-extension have traditionally been determined using single images collected at full flexion and full extension. These calculations neglect mid-range motion, and assume percentage contributions to motion remain constant throughout the entire flexion-extension range of motion (ROM). Methods 6 single-level (C5/C6) anterior arthrodesis patients and 18 asymptomatic control subjects performed flexion-extension while biplane radiographs were collected at 30 images per second. A previously validated tracking process determined three-dimensional vertebral position with sub-millimeter accuracy during continuous flexion-extension. Mixed-effects models of segmental percentage contribution to C2/C7 flexion-extension were developed to identify differences in percentage contribution within each motion segment, among motion segments, and between control and arthrodesis patients over the full ROM. Results The C2/C3, C3/C4 and C4/C5 motion segments made their maximum contributions during the mid-range of motion. The C5/C6 and C6/C7 motion segments, in contrast, made their maximum contributions near the start and end of the ROM. Arthrodesis patients’ contribution from the C4/C5 motion segment increased significantly over the range of motion from 30% to 95% of the total flexion-extension ROM (average increased contribution of 5.1%) and arthrodesis patients’ contribution from the C6/C7 motion segment increased significantly over the entire flexion-extension ROM (average increased percentage contribution of 8.9%) in comparison to controls. Conclusion Cervical motion segment contributions to flexion-extension change significantly during the flexion

  13. Using the IPAD as a Pedagogical Tool: Focus on Angular Motion Analysis with Real-World Applications

    NASA Astrophysics Data System (ADS)

    Bush, Leah; Garriott, Angela; Ramos, Roberto

    2012-02-01

    The IPAD is a portable, novel interface that has the potential to create a more interactive learning environment in undergraduate physics education, particularly in the introductory physics laboratory setting. We report our experience in using this pedagogical tool in an algebra-based physics laboratory course, focusing on its application in analysis of angular motion. Taking advantage of its portability, we use it to analyze motion not only using standard physics laboratory equipment but using it for analyzing motion in real-world applications such as with exercise equipment such as an exercise bicycle and an elliptical machine. We report on student response to this learning tool.

  14. SU-E-T-244: Motion Control Challenges in High Dose Rate Brachytherapy

    SciTech Connect

    Hyvarinen, M; Leventouri, T; Pella, S; Dumitru, N

    2014-06-01

    Purpose: High dose rate (HDR) brachytherapy dose distribution is highly localized and has a very sharp fall-off. Thus the one of the most important part of the treatment is the localization and immobilization of the applicator from the implantation to the setup verification to the treatment delivery. The smallest motions of the patient can induce a small rotation, tilt, or translational movement of the applicator that can convert into miss of a significant part of the tumor or to over irradiating a nearby critical organ.The purpose of this study is to revise most of the HDR types of treatments with their applicators and their localization challenges. Since every millimeter of misplacement counts the study will look into the necessity of increasing the immobilization for several types of applicators. Methods: The study took over 136 plans generated by the treatment planning system (TPS) looking into the applicator placement in regard to the organs at risk (OR) and simulated the three possible displacements at the hottest dose point on the critical organ for several accessories to evaluate the variation of the delivered dose at the point due to the displacement. Results: Many of the present immobilization devices produced for external radiotherapy can be used to improve the localization of HDR applicators during transportation of the patient and during treatment. Conclusion: This study data indicates that an improvement of the immobilization devices for HDR is absolutely necessary. Better applicator fixation devices are required too. Developing new immobilization devices for all the applicators is recommended.

  15. New Worlds Observer Formation Control Design Based on the Dynamics of Relative Motion

    NASA Technical Reports Server (NTRS)

    Luquette, Richard J.

    2008-01-01

    The New Worlds Observer (NWO) mission is designed for the direct detection and characterization of extrasolar planets. The NWO mission concept employs a two spacecraft leader-follower formation on a trajectory around the Earth/Moon-Sun L(sub 2) Libration Point. The leader spacecraft is baselined as a 4 meter optical telescope. The follower, Starshade spacecraft, is designed to suppress light from a central body star permitting direct detection of a surrounding exoplanetary system. The current design requires a nominal leader-follower separation range of 72 Megameters. NWO poses many challenges including formation control. NWO cycles between three principal control modes during the nominal mission timeline: science (fine pointing), realignment and transition. This paper examines formation control strategies in the context of dynamics of relative motion for two spacecraft operating in the vicinity of the Earth/Moon-Sun L(sub 2)libration point. The paper presents an overview of the equations of relative motion followed by a discussion of each of the control modes. Discussion and analysis characterize control strategies for each of the mission control modes, including requirements, implementation challenges and project fuel budgets.

  16. Motion interference analysis and optimal control of an electronic controlled bamboo-dance mechanism

    NASA Astrophysics Data System (ADS)

    Liu, Xiaohong; Xu, Liang; Hu, Xiaobin

    2017-08-01

    An electric bamboo-dance mechanism was designed and developed to realize mechanism of automation and mechanization. For coherent and fluent motion, ANSYS finite element analysis was applied on movement interference. Static structural method was used for analyzing dynamic deflection and deformation of the slender rod, while modal analysis was applied on frequency analysis to avoid second deformation caused by resonance. Therefore, the deformation in vertical and horizontal direction was explored and reasonable optimization was taken to avoid interference.

  17. Applications of AVHRR-Derived Ice Motions for the Arctic and Antarctic

    NASA Technical Reports Server (NTRS)

    Maslanik, James; Emery, William

    1998-01-01

    Characterization and diagnosis of sea ice/atmosphere/ocean interactions require a synthesis of observations and modeling to identify the key mechanisms controlling the ice/climate system. In this project, we combined product generation, observational analyses, and modeling to define and interpret variability in ice motion in conjunction with thermodynamic factors such as surface temperature and albedo. The goals of this work were twofold: (1) to develop and test procedures to produce an integrated set of polar products from remotely-sensed and supporting data; and (2) to apply these data to understand processes at work in controlling sea ice distribution.

  18. Oblique-wing research airplane motion simulation with decoupling control laws

    NASA Technical Reports Server (NTRS)

    Kempel, Robert W.; Mc Neill, Walter E.; Maine, Trindel A.

    1988-01-01

    A large piloted vertical motion simulator was used to assess the performance of a preliminary decoupling control law for an early version of the F-8 oblique wing research demonstrator airplane. Evaluations were performed for five discrete flight conditions, ranging from low-altitude subsonic Mach numbers to moderate-altitude supersonic Mach numbers. Asymmetric sideforce as a function of angle of attack was found to be the primary cause of both the lateral acceleration noted in pitch and the tendency to roll into left turns and out of right turns. The flight control system was shown to be effective in generally decoupling the airplane and reducing the lateral acceleration in pitch maneuvers.

  19. Layered Multicast Encryption of Motion JPEG2000 Code Streams for Flexible Access Control

    NASA Astrophysics Data System (ADS)

    Nakachi, Takayuki; Toyoshima, Kan; Tonomura, Yoshihide; Fujii, Tatsuya

    In this paper, we propose a layered multicast encryption scheme that provides flexible access control to motion JPEG2000 code streams. JPEG2000 generates layered code streams and offers flexible scalability in characteristics such as resolution and SNR. The layered multicast encryption proposal allows a sender to multicast the encrypted JPEG2000 code streams such that only designated groups of users can decrypt the layered code streams. While keeping the layering functionality, the proposed method offers useful properties such as 1) video quality control using only one private key, 2) guaranteed security, and 3) low computational complexity comparable to conventional non-layered encryption. Simulation results show the usefulness of the proposed method.

  20. The role of zygapophysial joint orientation and uncinate processes in controlling motion in the cervical spine.

    PubMed Central

    Milne, N

    1991-01-01

    Five linear and 2 angular measurements on each of C3 to T1 in a sample of 67 human skeletons were used to examine 3 hypotheses about the function of uncinate processes and zygapophysial joints in the cervical vertebral column. The material was sexed and each vertebra was rated for pathological changes. The effects of gender and pathology on the measures was assessed. The upper 4 vertebrae studied had the largest disc-facet angles, supporting the view that the articular facet orientation is responsible for the greater intervertebral disc translation occurring during sagittal motion in the neck. These upper 4 vertebrae also have the largest uncinate processes, and this observation supports the hypothesis that uncinate processes function to guide and control the anteroposterior translation which occurs during sagittal motion. The 3rd hypothesis that uncinate processes function to facilitate axial rotation is not supported by the recorded interfacet angles which appear to promote axial rotation only in the lower 4 vertebrae. Two further hypothesis are suggested. First, that the interfacet angle is responsible for controlling how strictly lateral flexion and axial rotation are coupled in cervical motion segments. Second, the suggestion is made that the high frequency of pathological change seen at the disc margins of the middle cervical vertebrae may be a result of the unusual combination of disc-facet and interfacet angles permitting more degrees of freedom than the cervical intervertebral discs can withstand. Images Fig. 3 Fig. 6 PMID:1810926

  1. Effect of reduced cutaneous cues on motion perception and postural control.

    PubMed

    Yi, Yongwoo; Park, Sukyung

    2009-05-01

    To investigate whether the sensory perception could be a more direct assessment of sensory deficit as oppose to the postural performance, we examined the effect of reduced cutaneous cues on motion perception and motion control. The subject was translated in a mediolateral direction with a single sinusoidal acceleration at a stimulus frequency of 0.25 Hz with a peak acceleration magnitude ranging from 0.25 to 8 mG in the dark. Two different plantar cutaneous conditions were provided: the control condition (barefoot) and the reduced cutaneous condition (foot on a spongy surface). For each foot-sole sensory condition, the subject completed six sets of 33 randomly ordered translation stimuli. After each translational stimulus, the subject reported their perceived direction of motion by pressing a hand-held button. The center of pressure (COP) and joint kinematics of the quiet stance were also measured. The results showed a significant increase in perception threshold as well as COP variation in the anteroposterior direction in the reduced cutaneous cue trials. However, a non-significant increase in COP in the mediolateral direction was shown. Multivariate covariance analysis of joint kinematics showed changes in postural coordination, such as increased reliance on hip strategy under reduced cutaneous cues condition, that have not been differentiated by univariate measures. The observed discrepancy in the significance of the contribution of plantar cutaneous cues to the detection threshold and the COP variation implies that the 'perception' could provide more direct and sensitive assessment of the sensory degradation than the 'action'.

  2. Using Unconstrained Tongue Motion as an Alternative Control Mechanism for Wheeled Mobility

    PubMed Central

    Huo, Xueliang; Ghovanloo, Maysam

    2015-01-01

    Tongue drive system (TDS) is a tongue-operated, minimally invasive, unobtrusive, noncontact, and wireless assistive technology that infers users’ intentions by detecting and classifying their voluntary tongue motions, and translating them to user-defined commands. We have developed customized interface circuitry between an external TDS (eTDS) prototype and a commercial powered wheelchair (PWC) as well as three control strategies to evaluate the tongue motion as an alternative control input for wheeled mobility. We tested the eTDS performance in driving PWCs on 12 able-bodied human subjects, of which 11 were novice. The results showed that all subjects could complete navigation tasks by operating the PWC using their tongue motions. Despite little prior experience, the average time using the eTDS and the tongue was only approximately three times longer than using a joystick and the fingers. Navigation time was strongly dependant on the number of issued commands, which reduced by gaining experience. Particularly, the unintended issued commands (the Midas touch problem) were rare, demonstrating the effectiveness of the tongue tracking and external magnetic field cancellation algorithms as well as the safety of the TDS for wheeled mobility. PMID:19362901

  3. Using unconstrained tongue motion as an alternative control mechanism for wheeled mobility.

    PubMed

    Huo, Xueliang; Ghovanloo, Maysam

    2009-06-01

    Tongue drive system (TDS) is a tongue-operated, minimally invasive, unobtrusive, noncontact, and wireless assistive technology that infers users' intentions by detecting and classifying their voluntary tongue motions, and translating them to user-defined commands. We have developed customized interface circuitry between an external TDS (eTDS) prototype and a commercial powered wheelchair (PWC) as well as three control strategies to evaluate the tongue motion as an alternative control input for wheeled mobility. We tested the eTDS performance in driving PWCs on 12 able-bodied human subjects, of which 11 were novice. The results showed that all subjects could complete navigation tasks by operating the PWC using their tongue motions. Despite little prior experience, the average time using the eTDS and the tongue was only approximately three times longer than using a joystick and the fingers. Navigation time was strongly dependant on the number of issued commands, which reduced by gaining experience. Particularly, the unintended issued commands (the Midas touch problem) were rare, demonstrating the effectiveness of the tongue tracking and external magnetic field cancellation algorithms as well as the safety of the TDS for wheeled mobility.

  4. Manual control theory and applications. [physiological and neurological applications

    NASA Technical Reports Server (NTRS)

    Sadoff, M.; Repa, B.

    1974-01-01

    Control theory, including manual control theory, and a review of some previous physiological and neurological applications of control theory and associated engineering concepts are reported. The discussion includes a specially tailored battery of critical control tasks that are being developed to monitor astronaut performance in long term orbital flight. The application of these concepts and tasks to patients with various neurological disorders is considered.

  5. Applications of computer-graphics animation for motion-perception research

    NASA Technical Reports Server (NTRS)

    Proffitt, D. R.; Kaiser, M. K.

    1986-01-01

    The advantages and limitations of using computer animated stimuli in studying motion perception are presented and discussed. Most current programs of motion perception research could not be pursued without the use of computer graphics animation. Computer generated displays afford latitudes of freedom and control that are almost impossible to attain through conventional methods. There are, however, limitations to this presentational medium. At present, computer generated displays present simplified approximations of the dynamics in natural events. Very little is known about how the differences between natural events and computer simulations influence perceptual processing. In practice, the differences are assumed to be irrelevant to the questions under study, and that findings with computer generated stimuli will generalize to natural events.

  6. Provision of Controlled Motion Accuracy of Industrial Robots and Multiaxis Machines by the Method of Integrated Deviations Correction

    NASA Astrophysics Data System (ADS)

    Krakhmalev, O. N.; Petreshin, D. I.; Fedonin, O. N.

    2016-04-01

    There is a developed method of correction of the integrated motion deviations of industrial robots and multiaxis machines, which are caused by the primary geometrical deviations of their segments. This method can be used to develop a control system providing the motion correction for industrial robots and multiaxis machines.

  7. Stretching and Controlled Motion of Single-Stranded DNA in Locally-Heated Solid-State Nanopores

    PubMed Central

    Belkin, Maxim; Maffeo, Christopher; Wells, David B.

    2013-01-01

    Practical applications of solid-state nanopores for DNA detection and sequencing require the electrophoretic motion of DNA through the nanopores to be precisely controlled. Controlling the motion of single-stranded DNA presents a particular challenge, in part because of the multitude of conformations that a DNA strand can adopt in a nanopore. Through continuum, coarse-grained and atomistic modeling, we demonstrate that local heating of the nanopore volume can be used to alter the electrophoretic mobility and conformation of single-stranded DNA. In the nanopore systems considered, the temperature near the nanopore is modulated via a nanometer-size heater element that can be radiatively switched on and off. The local enhancement of temperature produces considerable stretching of the DNA fragment confined within the nanopore. Such stretching is reversible, so that the conformation of DNA can be toggled between compact (local heating is off) and extended (local heating is on) states. The effective thermophoretic force acting on single-stranded DNA in the vicinity of the nanopore is found to be sufficiently large (4–8 pN) to affect such changes in the DNA conformation. The local heating of the nanopore volume is observed to promote single-file translocation of DNA strands at transmembrane biases as low as 10 mV, which opens new avenues for using solid-state nanopores for detection and sequencing of DNA. PMID:23876013

  8. The relationship of motion sickness susceptibility to learned autonomic control for symptom suppression

    NASA Technical Reports Server (NTRS)

    Cowings, P. S.; Toscano, W. B.

    1982-01-01

    Twenty-four men were randomly assigned to four equal groups matched in terms of their Coriolis Sickness Susceptibility Index (CSSI). Two groups of subjects were highly susceptible to motion sickness, and two groups were moderately susceptible. All subjects were given six C551 tests at 5-d intervals. Treatment Groups I (highly susceptible) and II (moderately susceptible) were taught to control their autonomic responses, using a training method called autogenic-feedback training (AFT) before the third, fourth, and fifth CSSI tests. Control groups III (highly susceptible) and IV (moderately susceptible) received no treatment. Results showed that both treatment groups significantly improved performance on CSSI tests after training; neither of the control groups changed significantly. Highly and moderately susceptible subjects in the two treatment groups improved at comparable rates. Highly susceptible control group subjects did not habituate across tests as readily as the moderately susceptible controls.

  9. The relationship of motion sickness susceptibility to learned autonomic control for symptom suppression

    NASA Technical Reports Server (NTRS)

    Cowings, P. S.; Toscano, W. B.

    1982-01-01

    Twenty-four men were randomly assigned to four equal groups matched in terms of their Coriolis Sickness Susceptibility Index (CSSI). Two groups of subjects were highly susceptible to motion sickness, and two groups were moderately susceptible. All subjects were given six C551 tests at 5-d intervals. Treatment Groups I (highly susceptible) and II (moderately susceptible) were taught to control their autonomic responses, using a training method called autogenic-feedback training (AFT) before the third, fourth, and fifth CSSI tests. Control groups III (highly susceptible) and IV (moderately susceptible) received no treatment. Results showed that both treatment groups significantly improved performance on CSSI tests after training; neither of the control groups changed significantly. Highly and moderately susceptible subjects in the two treatment groups improved at comparable rates. Highly susceptible control group subjects did not habituate across tests as readily as the moderately susceptible controls.

  10. Controlling the Motion of Electronic Wavepackets Using Cycle-Sculpted Two-Color Laser Fields

    NASA Astrophysics Data System (ADS)

    Kitzler, M.; Xie, X.; Roither, S.; Kartashov, D.; Baltuška, A.

    We use cycle-sculpted two-color waveforms to drive electronic wavepackets generated by strong-field ionization from helium, neon, and argon gas atoms and analyze their momentum spectra measured by electron-ion coincidence momentum spectroscopy. Varying the relative phase of the two colors allows to sculpt the ionizing field and hence to control the emission times and motion of the wavepackets on an attosecond timescale. Using semiclassical calculations, we investigate the influence of the ionic Coulomb field onto the motion of emitted electronic wavepackets. We further show that the measured electron momentum spectra contain interference patterns created by pairs of electron wavepackets that are released within a single laser-field cycle. We experimentally distinguish these subcycle interference structures from above-threshold ionization (ATI) peaks and argue that they can be used to extract the subcycle phase evolution of the laser-driven complex bound-state wavefunction.

  11. Design and performance evaluation of a coarse/fine precision motion control system

    SciTech Connect

    Yang, H; Buice, E S; Smith, S T; Hocken, R J; Fagan, T J; Trumper, D L; Otten, D; Seugling, R M

    2005-03-02

    This abstract presents current collaborative work on the development of a stage system for accurate nanometer level positioning for scanning specimens spanning an area of 50 mm x 50 mm. The completed system employs a coarse/fine approach which comprises a short-range, six degree-of-freedom fine-motion platform (5 microns 200 micro-radians) carried by a long-range, two-axis X-Y coarse positioning system. Relative motion of the stage to a fixed metrology frame will be measured using a heterodyne laser in an eight-pass interferometer configuration. The final stage system will be housed in a vacuum environment and operated in a temperature-controlled laboratory. Results from a simple single coarse/fine axis system will be the design basis for the final multi-axis system. It is expected that initial stage performance evaluation will be presented at the conference.

  12. Controlled Folding, Motional, and Constitutional Dynamic Processes of Polyheterocyclic Molecular Strands.

    PubMed

    Barboiu, Mihail; Stadler, Adrian-Mihail; Lehn, Jean-Marie

    2016-03-18

    General design principles have been developed for the control of the structural features of polyheterocyclic strands and their effector-modulated shape changes. Induced defined molecular motions permit designed enforcement of helical as well as linear molecular shapes. The ability of such molecular strands to bind metal cations allows the generation of coiling/uncoiling processes between helically folded and extended linear states. Large molecular motions are produced on coordination of metal ions, which may be made reversible by competition with an ancillary complexing agent and fueled by sequential acid/base neutralization energy. The introduction of hydrazone units into the strands confers upon them constitutional dynamics, whereby interconversion between different strand compositions is achieved through component exchange. These features have relevance for nanomechanical devices. We present a morphological and functional analysis of such systems developed in our laboratories.

  13. Friction control using ultrasonic oscillation for rolling-element linear-motion guide

    SciTech Connect

    Oiwa, Takaaki

    2006-01-15

    This article reports a friction-control method for rolling-element linear-motion guides used for precision positioning. In general, static friction greater than dynamic friction generates stick-slip motion and diminishes the positioning accuracy. Two ultrasonic actuators excite both the rail and the carriage of the guide to give relative displacements to bearing surfaces. In order to effectively propagate the vibration over the entire rail without damping, the actuator drives at that frequency with a half wavelength corresponding to the distances between the rail mounting bolts. This also minimizes undesirable vibration of the machine structure. Moreover, the bearing surfaces of the carriage are resonated by a second ultrasonic actuator. The experiments using a force sensor showed that the static and dynamic friction forces were reduced by approximately 25% at any place on the 600-mm-long rail. Moreover, excitation only at very low velocity decreased the static friction peak.

  14. Control of self-motion in dynamic fluids: fish do it differently from bees.

    PubMed

    Scholtyssek, Christine; Dacke, Marie; Kröger, Ronald; Baird, Emily

    2014-05-01

    To detect and avoid collisions, animals need to perceive and control the distance and the speed with which they are moving relative to obstacles. This is especially challenging for swimming and flying animals that must control movement in a dynamic fluid without reference from physical contact to the ground. Flying animals primarily rely on optic flow to control flight speed and distance to obstacles. Here, we investigate whether swimming animals use similar strategies for self-motion control to flying animals by directly comparing the trajectories of zebrafish (Danio rerio) and bumblebees (Bombus terrestris) moving through the same experimental tunnel. While moving through the tunnel, black and white patterns produced (i) strong horizontal optic flow cues on both walls, (ii) weak horizontal optic flow cues on both walls and (iii) strong optic flow cues on one wall and weak optic flow cues on the other. We find that the mean speed of zebrafish does not depend on the amount of optic flow perceived from the walls. We further show that zebrafish, unlike bumblebees, move closer to the wall that provides the strongest visual feedback. This unexpected preference for strong optic flow cues may reflect an adaptation for self-motion control in water or in environments where visibility is limited.

  15. Application of quadratic optimization to supersonic inlet control

    NASA Technical Reports Server (NTRS)

    Lehtinen, B.; Zeller, J. R.

    1971-01-01

    The application of linear stochastic optimal control theory to the design of the control system for the air intake (inlet) of a supersonic air-breathing propulsion system is discussed. The controls must maintain a stable inlet shock position in the presence of random airflow disturbances and prevent inlet unstart. Two different linear time invariant control systems are developed. One is designed to minimize a nonquadratic index, the expected frequency of inlet unstart, and the other is designed to minimize the mean square value of inlet shock motion. The quadratic equivalence principle is used to obtain the best linear controller that minimizes the nonquadratic performance index. The two systems are compared on the basis of unstart prevention, control effort requirements, and sensitivity to parameter variations.

  16. In vivo quantification of motion in liver parenchyma and its application in shistosomiasis tissue characterization

    NASA Astrophysics Data System (ADS)

    Badawi, Ahmed M.; Hashem, Ahmed M.; Youssef, Abou-Bakr M.; Abdel-Wahab, Mohamed F.

    1995-03-01

    Schistosomiasis is a major problem in Egypt, despite an active control program it is estimated to exist in about 1/3 of the population. Deposition of less functioning fibrous tissues in the liver is the major contributory factor to the hepatic pathology. Fibrous tissues consist of a complex array of connective matrix material and a variety of collagen isotopes. As a result of an increased stromal density (collagen content), the parenchyma became more ectogenic and less elastic (hard). In this study we investigated the effect of cardiac mechanical impulses from the heart and aorta on the kinetics of the liver parenchyma. Under conditions of controlled patient movements and suspended respiration, a 30 frame per second of 588 X 512 ultrasound images (cineloop, 32 pels per cm) are captured from an aTL ultrasound machine then digitized. The image acquisition is triggered by the R wave of the ECG of the patient. The motion that has a forced oscillation form in the liver parenchyma is quantified by tracking of small box (20 - 30 pels) in 16 directions for all the successive 30 frames. The tracking was done using block matching techniques (the max correlation between boxes in time, frequency domains, and the minimum SAD (sum absolute difference) between boxes). The motion is quantified for many regions at different positions within the liver parenchyma for 80 cases of variable degrees of schisto., cirrhotic livers, and for normal livers. The velocity of the tissue is calculated from the displacement (quantified motion), time between frames, and the scan time for the ultrasound scanner. We found that the motion in liver parenchyma is small in the order of very few millimeters, and the attenuation of the mechanical wave for one ECG cycle is higher in the schisto. and cirrhotic livers than in the normal ones. Finally quantification of motion in liver parenchyma due to cardiac impulses under controlled limb movement and respiration may be of value in the characterization of

  17. Motion planning and synchronized control of the dental arch generator of the tooth-arrangement robot.

    PubMed

    Jiang, Jin-Gang; Zhang, Yong-De

    2013-03-01

    The traditional, manual method of reproducing the dental arch form is prone to numerous random errors caused by human factors. The purpose of this study was to investigate the automatic acquisition of the dental arch and implement the motion planning and synchronized control of the dental arch generator of the multi-manipulator tooth-arrangement robot for use in full denture manufacture. First, the mathematical model of the dental arch generator was derived. Then the kinematics and control point position of the dental arch generator of the tooth arrangement robot were calculated and motion planning of each control point was analysed. A hardware control scheme is presented, based on the industrial personal computer and control card PC6401. In order to gain single-axis, precise control of the dental arch generator, we studied the control pulse realization of high-resolution timing. Real-time, closed-loop, synchronous control was applied to the dental arch generator. Experimental control of the dental arch generator and preliminary tooth arrangement were gained by using the multi-manipulator tooth-arrangement robotic system. The dental arch generator can automatically generate a dental arch to fit a patient according to the patient's arch parameters. Repeated positioning accuracy is 0.12 mm for the slipways that drive the dental arch generator. The maximum value of single-point error is 1.83 mm, while the arc-width direction (x axis) is -33.29 mm. A novel system that generates the dental arch has been developed. The traditional method of manually determining the dental arch may soon be replaced by a robot to assist in generating a more individual dental arch. The system can be used to fabricate full dentures and bend orthodontic wires. Copyright © 2012 John Wiley & Sons, Ltd.

  18. Comparison of three different techniques for camera and motion control of a teleoperated robot.

    PubMed

    Doisy, Guillaume; Ronen, Adi; Edan, Yael

    2017-01-01

    This research aims to evaluate new methods for robot motion control and camera orientation control through the operator's head orientation in robot teleoperation tasks. Specifically, the use of head-tracking in a non-invasive way, without immersive virtual reality devices was combined and compared with classical control modes for robot movements and camera control. Three control conditions were tested: 1) a condition with classical joystick control of both the movements of the robot and the robot camera, 2) a condition where the robot movements were controlled by a joystick and the robot camera was controlled by the user head orientation, and 3) a condition where the movements of the robot were controlled by hand gestures and the robot camera was controlled by the user head orientation. Performance, workload metrics and their evolution as the participants gained experience with the system were evaluated in a series of experiments: for each participant, the metrics were recorded during four successive similar trials. Results shows that the concept of robot camera control by user head orientation has the potential of improving the intuitiveness of robot teleoperation interfaces, specifically for novice users. However, more development is needed to reach a margin of progression comparable to a classical joystick interface. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Organ motion due to respiration: the state of the art and applications in interventional radiology and radiation oncology

    NASA Astrophysics Data System (ADS)

    Cleary, Kevin R.; Mulcahy, Maureen; Piyasena, Rohan; Zhou, Tong; Dieterich, Sonja; Xu, Sheng; Banovac, Filip; Wong, Kenneth H.

    2005-04-01

    Tracking organ motion due to respiration is important for precision treatments in interventional radiology and radiation oncology, among other areas. In interventional radiology, the ability to track and compensate for organ motion could lead to more precise biopsies for applications such as lung cancer screening. In radiation oncology, image-guided treatment of tumors is becoming technically possible, and the management of organ motion then becomes a major issue. This paper will review the state-of-the-art in respiratory motion and present two related clinical applications. Respiratory motion is an important topic for future work in image-guided surgery and medical robotics. Issues include how organs move due to respiration, how much they move, how the motion can be compensated for, and what clinical applications can benefit from respiratory motion compensation. Technology that can be applied for this purpose is now becoming available, and as that technology evolves, the subject will become an increasingly interesting and clinically valuable topic of research.

  20. Measurements of human force control during a constrained arm motion using a force-actuated joystick.

    PubMed

    McIntyre, J; Gurfinkel, E V; Lipshits, M I; Droulez, J; Gurfinkel, V S

    1995-03-01

    1. When interacting with the environment, human arm movements may be prevented in certain directions (i.e., when sliding the hand along a surface) resulting in what is called a "constrained motion." In the directions that the movement is restricted, the subject is instead free to control the forces against the constraint. 2. Control strategies for constrained motion may be characterized by two extreme models. Under the active compliance model, an essentially feedback-based approach, measurements of contact force may be used in real time to modify the motor command and precisely control the forces generated against the constraint. Under the passive compliance model the motion would be executed in a feedforward manner, using an internal model of the constraint geometry. The feedforward model relies on the compliant behavior of the passive mechanical system to maintain contact while avoiding excessive contact forces. 3. Subjects performed a task in which they were required to slide the hand along a rigid surface. This task was performed in a virtual force environment in which contact forces were simulated by a two-dimensional force-actuated joystick. Unknown to the subject, the orientation of the surface constraint was varied from trial to trial, and contact force changes induced by these perturbations were measured. 4. Subjects showed variations in contact force correlated with the direction of the orientation perturbation. "Upward" tilts resulted in higher contact forces, whereas "downward" tilts resulted in lower contact forces. This result is consistent with a feedforward-based control of a passively compliant system. 5. Subject responses did not, however, correspond exactly to the predictions of a static analysis of a passive, feedforward-controlled system. A dynamic analysis reveals a much closer resemblance between a passive, feedforward model and the observed data. Numerical simulations demonstrate that a passive, dynamic system model of the movement captures

  1. Materials and processes control for space applications

    NASA Technical Reports Server (NTRS)

    Blackburn, G. A.

    1985-01-01

    Materials and processes control relative to space applications is discussed. The components of a total material and process control system are identified, contamination control issues are listed, and recommendations are made.

  2. Early testing of a coarse/fine precision motion control system

    SciTech Connect

    Buice, E S; Yang, H; Smith, S T; Hocken, R J; Seugling, R M; Trumper, D L; Otten, D

    2005-08-01

    This abstract presents a brief overview of key components of a motion control stage for accurate nanometer level positioning for scanning specimens over an area measuring 50 mm x 50 mm. The completed system will utilize a short-range, third generation 6 degree-of-freedom fine motion control platform (4 microns, 160 micro-radians) carried by a long-range, two-axis x-y positioning system (50 mm x 50 mm). Motion of the controlled platform relative to a measurement frame will be measured using a heterodyne laser interferometer and capacitance sensing. The final stage will be mounted onto an isolation table in a vacuum chamber, itself on isolation supports mounted to a granite slab on bed rock and isolated from the main floor of the building. This whole system is housed in a temperature-controlled laboratory. It is envisaged that the current system will provide the ability to ''pick and place'' at nanometer levels and be used for long range scanning of specimens (including biological specimens), micro- /macroassembly, lithography and as a coordinate measuring machine (CMM). Furthermore, the system performance will be compared with other comparable systems at international locations such as, National Physical Laboratory (NPL) in the UK, Technical University of Eindhoven (TUE) in the Netherlands, Physikalisch-Technische Bundesanstalt (PTB) in Germany, and our own sub-atomic measuring machine (SAMM) [1, 2] at UNC-Charlotte. Critical requirements of the system are as follows: (1) Vacuum compatible to better than 20 mPa; (2) Range of 50 mm x 50 mm x 4 microns; (3) Maximum translation velocity of 5 mm {center_dot} s{sup -1}; (4) Sub-nanometer resolution; and (5) System accuracy of better than 10 nm.

  3. Motion-Capture-Enabled Software for Gestural Control of 3D Models

    NASA Technical Reports Server (NTRS)

    Norris, Jeffrey S.; Luo, Victor; Crockett, Thomas M.; Shams, Khawaja S.; Powell, Mark W.; Valderrama, Anthony

    2012-01-01

    Current state-of-the-art systems use general-purpose input devices such as a keyboard, mouse, or joystick that map to tasks in unintuitive ways. This software enables a person to control intuitively the position, size, and orientation of synthetic objects in a 3D virtual environment. It makes possible the simultaneous control of the 3D position, scale, and orientation of 3D objects using natural gestures. Enabling the control of 3D objects using a commercial motion-capture system allows for natural mapping of the many degrees of freedom of the human body to the manipulation of the 3D objects. It reduces training time for this kind of task, and eliminates the need to create an expensive, special-purpose controller.

  4. Precision motion control with a high gain disturbance compensator for linear motors.

    PubMed

    Tan, Kok Kiong; Zhao, Shao

    2004-07-01

    In this paper, we address the problem relating to the precision control of permanent magnet linear motors to track repeated motion trajectories. A high gain disturbance compensator is developed to improve the control performance degraded due to the presence of significant disturbances. An inverse gain of the overall system model is used to set up a disturbance observer. The observed disturbance is then used to generate a "knocker" signal, to be augmented to the control signal, which can provide the additional energy necessary to overcome the effects of the disturbances. A learning scheme is used to adjust the knocker signal iteratively over the repeated cycles. Simulation and experimental results are furnished to demonstrate the effectiveness of the proposed control scheme.

  5. Can Rehabilitation Influence the Efficiency of Control Signals in Complex Motion Strategies?

    PubMed

    Cholewa, Joanna; Cholewa, Jaroslaw; Gorzkowska, Agnieszka; Malecki, Andrzej; Stanula, Arkadiusz

    2017-01-01

    The factor determining quality of life in Parkinson's disease (PD) is the worsening of a patient's walking ability. The use of external stimuli can improve gait when performing complex motor patterns. The aim of this study was to evaluate the effect of rehabilitation on the effectiveness of control signals in people with PD. The study was performed on 42 people with idiopathic PD in the third stage of disease. The control group consisted of 19 patients who did not participate in rehabilitation activities. The experimental group was systematically participating in rehabilitation activities twice a week (60 minutes) for 9 months. Gait speed, mean step length, and step frequency were calculated on the basis of the obtained results. These parameters were compared in both groups by single factor variance analyses. The best results were obtained using rhythmic external auditory signals. The group with patients actively participating in rehabilitation showed statistically significant improvement in gait speed (12.35%), mean step length (18.00%), and frequency step (2.40%) compared to the control group. The presented research showed the positive effect of rehabilitation and was based on the performance of complex motion patterns, using external control signals for their effectiveness in new motion tasks.

  6. Can Rehabilitation Influence the Efficiency of Control Signals in Complex Motion Strategies?

    PubMed Central

    Cholewa, Joanna; Gorzkowska, Agnieszka; Malecki, Andrzej; Stanula, Arkadiusz

    2017-01-01

    The factor determining quality of life in Parkinson's disease (PD) is the worsening of a patient's walking ability. The use of external stimuli can improve gait when performing complex motor patterns. The aim of this study was to evaluate the effect of rehabilitation on the effectiveness of control signals in people with PD. The study was performed on 42 people with idiopathic PD in the third stage of disease. The control group consisted of 19 patients who did not participate in rehabilitation activities. The experimental group was systematically participating in rehabilitation activities twice a week (60 minutes) for 9 months. Gait speed, mean step length, and step frequency were calculated on the basis of the obtained results. These parameters were compared in both groups by single factor variance analyses. The best results were obtained using rhythmic external auditory signals. The group with patients actively participating in rehabilitation showed statistically significant improvement in gait speed (12.35%), mean step length (18.00%), and frequency step (2.40%) compared to the control group. The presented research showed the positive effect of rehabilitation and was based on the performance of complex motion patterns, using external control signals for their effectiveness in new motion tasks. PMID:28626755

  7. Application of model based control to robotic manipulators

    NASA Technical Reports Server (NTRS)

    Petrosky, Lyman J.; Oppenheim, Irving J.

    1988-01-01

    A robot that can duplicate humam motion capabilities in such activities as balancing, reaching, lifting, and moving has been built and tested. These capabilities are achieved through the use of real time Model-Based Control (MBC) techniques which have recently been demonstrated. MBC accounts for all manipulator inertial forces and provides stable manipulator motion control even at high speeds. To effectively demonstrate the unique capabilities of MBC, an experimental robotic manipulator was constructed, which stands upright, balancing on a two wheel base. The mathematical modeling of dynamics inherent in MBC permit the control system to perform functions that are impossible with conventional non-model based methods. These capabilities include: (1) Stable control at all speeds of operation; (2) Operations requiring dynamic stability such as balancing; (3) Detection and monitoring of applied forces without the use of load sensors; (4) Manipulator safing via detection of abnormal loads. The full potential of MBC has yet to be realized. The experiments performed for this research are only an indication of the potential applications. MBC has no inherent stability limitations and its range of applicability is limited only by the attainable sampling rate, modeling accuracy, and sensor resolution. Manipulators could be designed to operate at the highest speed mechanically attainable without being limited by control inadequacies. Manipulators capable of operating many times faster than current machines would certainly increase productivity for many tasks.

  8. Active breathing control (ABC): Determination and reduction of breathing-induced organ motion in the chest

    SciTech Connect

    Gagel, Bernd . E-mail: BGagel@UKAachen.de; Demirel, Cengiz M.P.; Kientopf, Aline; Pinkawa, Michael; Piroth, Marc; Stanzel, Sven; Breuer, Christian; Asadpour, Branka; Jansen, Thomas; Holy, Richard; Wildberger, Joachim E.; Eble, Michael J.

    2007-03-01

    Purpose: Extensive radiotherapy volumes for tumors of the chest are partly caused by interfractional organ motion. We evaluated the feasibility of respiratory observation tools using the active breathing control (ABC) system and the effect on breathing cycle regularity and reproducibility. Methods and Materials: Thirty-six patients with unresectable tumors of the chest were selected for evaluation of the ABC system. Computed tomography scans were performed at various respiratory phases starting at the same couch position without patient movement. Threshold levels were set at minimum and maximum volume during normal breathing cycles and at a volume defined as shallow breathing, reflecting the subjective maximal tolerable reduction of breath volume. To evaluate the extent of organ movement, 13 landmarks were considering using commercial software for image coregistration. In 4 patients, second examinations were performed during therapy. Results: Investigating the differences in a normal breathing cycle versus shallow breathing, a statistically significant reduction of respiratory motion in the upper, middle, and lower regions of the chest could be detected, representing potential movement reduction achieved through reduced breath volume. Evaluating interfraction reproducibility, the mean displacement ranged between 0.24 mm (chest wall/tracheal bifurcation) to 3.5 mm (diaphragm) for expiration and shallow breathing and 0.24 mm (chest wall) to 5.25 mm (diaphragm) for normal inspiration. Conclusions: By modifying regularity of the respiratory cycle through reduction of breath volume, a significant and reproducible reduction of chest and diaphragm motion is possible, enabling reduction of treatment planning margins.

  9. Self-sustained motion of microcapsules on a substrate controlled via the repressilator regulatory network

    NASA Astrophysics Data System (ADS)

    Shum, Henry; Yashin, Victor; Balazs, Anna

    2014-11-01

    We design microcapsules that undergo self-induced motion in a fluid along a substrate and are able to collectively self-organize when controlled by a biomimetic signaling network. Three microcapsules act as localized sources of distinct chemicals that diffuse through the fluid. The production rate of each chemical is modulated by a regulatory network known as the repressilator: each species represses the production of the next in a cycle. We show that this system can exhibit sustained oscillations. We then allow the diffusing species to adsorb onto the substrate, altering the surface interaction energy. Gradients in surface energy lead to motion of the microcapsules. We find that regulation via the repressilator gives rise to qualitatively different outcomes. Chemical oscillations can facilitate aggregation of the microcapsules and the aggregate can undergo sustained translational or oscillatory motion. Numerical simulation of the fluid flow, microcapsule dynamics and concentration fields is achieved by a combination of the lattice Boltzmann, immersed boundary and finite difference methods. We assess the role of hydrodynamic interactions by comparison with a simplified model that assumes a constant drag coefficient relating the force on a microcapsule to its velocity.

  10. Motion Control of Drives for Prosthetic Hand Using Continuous Myoelectric Signals

    NASA Astrophysics Data System (ADS)

    Purushothaman, Geethanjali; Ray, Kalyan Kumar

    2016-03-01

    In this paper the authors present motion control of a prosthetic hand, through continuous myoelectric signal acquisition, classification and actuation of the prosthetic drive. A four channel continuous electromyogram (EMG) signal also known as myoelectric signals (MES) are acquired from the abled-body to classify the six unique movements of hand and wrist, viz, hand open (HO), hand close (HC), wrist flexion (WF), wrist extension (WE), ulnar deviation (UD) and radial deviation (RD). The classification technique involves in extracting the features/pattern through statistical time domain (TD) parameter/autoregressive coefficients (AR), which are reduced using principal component analysis (PCA). The reduced statistical TD features and or AR coefficients are used to classify the signal patterns through k nearest neighbour (kNN) as well as neural network (NN) classifier and the performance of the classifiers are compared. Performance comparison of the above two classifiers clearly shows that kNN classifier in identifying the hidden intended motion in the myoelectric signals is better than that of NN classifier. Once the classifier identifies the intended motion, the signal is amplified to actuate the three low power DC motor to perform the above mentioned movements.

  11. Neural-network-based fuzzy logic control system with applications on compliant robot control

    NASA Astrophysics Data System (ADS)

    Hor, MawKae; Lu, Hui L.

    1994-10-01

    In view of the success of neural network applications in inverted pendulum control, speech recognition, and other problem solving, we believe that one could inject the noise removing concepts and learning spirits into the algorithm in constructing the neural networks and apply it to the various tasks such as compliant coordinated motion using multiple robots. Based on the fuzzy logic, a fuzzy logical control system is a logical system which is much closer to human thinking than any other logical systems. During recent years, fuzzy logic control has emerged as a fruitful area in applications, especially the applications lacking quantitative data regarding the input-output relations. Whereas, the connectionist model injects the learning ability to the fuzzy logic system. This model, proposed by Lin and Lee, is a connected neural network that embedded the fuzzy rules in the architecture. Since this model is general enough and we expect the embedded fuzzy concepts can solve the problems caused by the defective training data, it is chosen as our base structure. Appropriate modifications have been made to this model to reflect the real situations encountered in the robot applications. Our goal is to control two different types of robots for coordinated motion using sensory feedback information.

  12. Respiratory Motion of The Heart and Positional Reproducibility Under Active Breathing Control

    SciTech Connect

    Jagsi, Reshma; Moran, Jean M.; Kessler, Marc L.; Marsh, Robin B. C; Balter, James M.; Pierce, Lori J. . E-mail: ljpierce@umich.edu

    2007-05-01

    Purpose: To reduce cardiotoxicity from breast radiotherapy (RT), innovative techniques are under investigation. Information about cardiac motion with respiration and positional reproducibility under active breathing control (ABC) is necessary to evaluate these techniques. Methods and Materials: Patients requiring loco-regional RT for breast cancer were scanned by computed tomography using an ABC device at various breath-hold states, before and during treatment. Ten patients were studied. For each patient, 12 datasets were analyzed. Mutual information-based regional rigid alignment was used to determine the magnitude and reproducibility of cardiac motion as a function of breathing state. For each scan session, motion was quantified by evaluating the displacement of a point along the left anterior descending artery (LAD) with respect to its position at end expiration. Long-term positional reproducibility was also assessed. Results: Displacement of the LAD was greatest in the inferior direction, moderate in the anterior direction, and lowest in the left-right direction. At shallow breathing states, the average displacement of LAD position was up to 6 mm in the inferior direction. The maximum displacement in any patient was 2.8 cm in the inferior direction, between expiration and deep-inspiration breath hold. At end expiration, the long-term reproducibility (SD) of the LAD position was 3 mm in the A-P, 6 mm in the S-I, and 4 mm in the L-R directions. At deep-inspiration breath hold, long-term reproducibility was 3 mm in the A-P, 7 mm in the S-I, and 3 mm in the L-R directions. Conclusions: These data demonstrate the extent of LAD displacement that occurs with shallow breathing and with deep-inspiration breath hold. This information may guide optimization studies considering the effects of respiratory motion and reproducibility of cardiac position on cardiac dose, both with and without ABC.

  13. Electromechanical actuation with controllable motion based on a single-walled carbon nanotube and natural biopolymer composite.

    PubMed

    Hu, Ying; Chen, Wei; Lu, Luhua; Liu, Jinghai; Chang, Chunrui

    2010-06-22

    This paper reports novel electromechanical behavior for a natural biopolymer film due to the incorporation of a conductive carbon nanotube network. Through simple solution blending and casting, high weight fraction single-walled carbon nanotube-chitosan composite films were fabricated and exhibited electromechanical actuation properties with motion controlled by low alternating voltage stimuli in atmospheric conditions. Of particular interest and importance is that the displacement output imitated perfectly the electrical input signal in terms of frequency (<10 Hz) and waveform. Operational reliability was confirmed by stable vibration testing in air for more than 3000 cycles. Proposed electrothermal mechanism considering the alternating current-induced periodic thermal expansion and contraction of the composite film was discussed. The unique actuation performance of the carbon nanotube-biopolymer composite, coupled with ease of fabrication, low driven voltage, tunable vibration, reliable operation, and good biocompatibility, shows great possibility for implementation of dry actuators in artificial muscle and microsystems for biomimetic applications.

  14. Materials Control for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Ferguson, Michael

    2005-01-01

    The distant future of mankind and the ultimate survivability of the human race, as it is known today, will depend on mans' ability to break earthly bonds and establish new territorial positions throughout the universe. Man must therefore be positioned to not only travel to, but also, to readily adapt to numerous and varying environments. For this mass migration across the galaxies nothing is as import to the human race as is NASA's future missions into Low Earth Orbit (LEO), to the moon, and/or Mars. These missions will form the building blocks to eternity for mankind. From these missions, NASA will develop the foundations for these building blocks based on sound engineering and scientific principles, both known and yet to be discovered. The integrity of the program will lead to development, tracking and control of the most basic elements of hardware production: That being development and control of applications of space flight materials. Choosing the right material for design purposes involves many considerations, such as governmental regulations associated with manufacturing operations, both safety of usage and of manufacturing, general material usage requirements, material longevity and performance requirements, material interfacing compatibility and material usage environments. Material performance is subject to environmental considerations in as much as a given material may perform exceptionally well at standard temperatures and pressures while performing poorly under non-standard conditions. These concerns may be found true for materials relative to the extreme temperatures and vacuum gradients of high altitude usage. The only way to assure that flight worthy materials are used in design is through testing. However, as with all testing, it requires both time on schedule and cost to the operation. One alternative to this high cost testing approach is to rely on a materials control system established by NASA. The NASA community relies on the MAPTIS materials

  15. [An attempt to evaluate postural control with a magnetic motion capture system].

    PubMed

    Kudo, Koji; Mitobe, Kazutaka; Honda, Kohei; Ishikawa, Kazuo

    2013-10-01

    Measurement of the body sway can be useful in the assessment of the ability to maintain posture. It is, however, difficult to quantitatively evaluate the chronological changes in the equilibrium function in the elderly. Although it is considered that not only sway movement of body center of gravity but also head movement should be measured for essential assessment of postural control, few methods are suitable for a clinical test. In this study, we investigated the head and trunk movement in elderly subjects standing upright, using a magnetic motion capture system to substantiate its usefulness. Seven subjects aged 66 to 83 years old were instructed to stand with their feet close together on the stabilometer with eyes open and then eyes closed for periods of 30 seconds each, while the movement of the head, cervix and lumbar region (MH, MC and ML) were monitored three-dimensionally with the magnetic motion capture system. The obtained data were compared with the movement of the body's center of gravity (MCG). The results were as follows: The MH was the largest, followed by MC and ML, and the ML trace was similar to that of the MCG. MH, MC, ML and the ratio of the MH to ML increased with age, and they were considered to be a valid index for assessment of postural control. A magnetic motion capture system, which can record the movements of the head, cervix and lumbar region accurately and conveniently, is seen as potentially and clinically useful apparatus for evaluation of postural control in dizzy patients, especially the elderly.

  16. Application of a spring-dashpot system to clinical lung tumor motion data

    SciTech Connect

    Ackerley, E. J.; Wilson, P. L.; Cavan, A. E.; Berbeco, R. I.; Meyer, J.

    2013-02-15

    Purpose: The treatment efficacy of radiation therapy for lung tumors can be increased by compensating for breath-induced tumor motion. In this study, we quantitatively examine a mathematical model of pseudomechanical linkages between an external surrogate signal and lung tumor motion. Methods: A spring-dashpot system based on the Voigt model was developed to model the correlation between abdominal respiratory motion and tumor motion during lung radiotherapy. The model was applied to clinical data obtained from 52 treatments ('beams') from 10 patients, treated on the Mitsubishi Real-Time Radiation Therapy system, Sapporo, Japan. In Stage 1, model parameters were optimized for individual patients and beams to determine reference values and to investigate how well the model can describe the data. In Stage 2, for each patient the optimal parameters determined for a single beam were applied to data from other beams to investigate whether a beam-specific set of model parameters is sufficient to model tumor motion over a course of treatment. Results: In Stage 1, the baseline root mean square (RMS) residual error for all individually optimized beam data was 0.90 {+-} 0.40 mm (mean {+-} 1 standard deviation). In Stage 2, patient-specific model parameters based on a single beam were found to model the tumor position closely, even for irregular beam data, with a mean increase with respect to Stage 1 values in RMS error of 0.37 mm. On average, the obtained model output for the tumor position was 95% of the time within an absolute bound of 2.0 and 2.6 mm in Stages 1 and 2, respectively. The model was capable of dealing with baseline, amplitude and frequency variations of the input data, as well as phase shifts between the input abdominal and output tumor signals. Conclusions: These results indicate that it may be feasible to collect patient-specific model parameters during or prior to the first treatment, and then retain these for the rest of the treatment period. The model has

  17. The motion control of a statically stable biped robot on an uneven floor.

    PubMed

    Shih, C L; Chiou, C J

    1998-01-01

    This work studies the motion control of a statically stable biped robot having seven degrees of freedom. Statically stable walking of the biped robot is realized by maintaining the center-of-gravity inside the convex region of the supporting foot and/or feet during both single-support and double-support phases. The main points of this work are framing the stability in an easy and correct way, the design of a bipedal statically stable walker, and walking on sloping surfaces and stairs.

  18. Design and Control of a Ship Motion Simulation Platform from an Energy Efficiency Perspective

    SciTech Connect

    Lind, Randall F; Jansen, John F; Love, Lonnie J; Lloyd, Peter D; Rowe, John C; Pin, Francois G

    2009-01-01

    Most hydraulic servo systems are designed with little consideration for energy efficiency. Pumps are selected based upon required peak power demands, valves are chosen primarily for their rated flow, actuators for the maximum force. However, the design of a hydraulic servo system has great potential in terms of energy efficiency that has, for the most part, been ignored. This paper describes the design and control of a large-scale ship motion simulation platform that was designed and built at Oak Ridge National Laboratory for the Office of Naval Research. The primary reasons to incorporate energy-efficiency features into the design are cost and size reduction. A preliminary survey of proposed designs based on traditional motion simulation platform configurations (Stuart Platforms) required hydraulic power supplies approaching 1.22 MW. This manuscript describes the combined design and control effort that led to a system with the same performance requirements, however requiring a primary power supply that was less than 112 kW. The objective of this paper is to illustrate alternative design and control approaches that can significantly reduce the power requirements of hydraulic systems and improve the overall energy-efficiency of large-scale hydraulically actuated systems.

  19. Principles and application of range of motion and stretching in companion animals.

    PubMed

    Marcellin-Little, Denis J; Levine, David

    2015-01-01

    Optimal function after injury, surgery, or in patients with chronic conditions requires adequate motion in joints, muscles, tendon, fascia, and skin. Range of motion and stretching exercises are commonly used in companion animal rehabilitation programs to maintain or improve motion of musculoskeletal tissues. Range of motion exercises and stretching prevent adhesions from forming, help scar tissue remodeling, may improve muscle tone, and prevent future injury from occurring. Stretching is used to avoid loss of motion or to regain lost joint motion. Stretching is done manually, using external coaptation, or using therapeutic exercises. Careful documentation of range of motion is necessary. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Preparation of surface coatings on a conductive substrate by controlled motion of graphene nanoflakes in a liquid medium

    NASA Astrophysics Data System (ADS)

    Zhang, X. F.; Qin, R. S.

    2015-02-01

    Controlled motion of graphene and graphene oxide nanoflakes in a thin liquid film on metal surfaces was studied to unravel the significant variations of the electric field effects on the nanoparticles. It was found that graphene oxide flakes were negatively charged and migrated toward anode while the electrically neutral graphene flakes moved toward cathode. Therefore, thin layers of graphene as a protective coating were produced to inhibit corrosion of underlying metals and reduce friction and wear-related mechanical failures in moving mechanical systems. The method does not require an insulated substrate to confine the high electric field to the fluidic layer. The motion of the nano-particles under pulsed electric current was very efficient. The observed effects were interpreted in a possible mechanism associated to the effect of electric field on the mobility of different particles in different conductive media. This significant phenomenon, combined with unique properties of graphene and graphene oxides, represents an exciting platform for enabling diverse applications on the preparation of protective coatings on an arbitrary conductive substrate over large areas.