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Sample records for flexible long-reach manipulators

  1. Telerobotic operation of structurally flexible, long-reach manipulators

    SciTech Connect

    Kwon, D.S.; Hwang, D.H.; Babcock, S.M.

    1994-09-01

    As a part of the Department of Energy`s Environmental Restoration and Waste Management Program, long-reach manipulators are being considered for the retrieval of waste from large storage tanks. Long-reach manipulators may have characteristics significantly different from those of typical industrial robots because of the flexibility of long links needed to cover the large workspace. To avoid structural vibrations during operation, control algorithms employing various types of shaping filters were investigated. A new approach that uses embedded simulation was developed and compared with others. In the new approach, generation of joint trajectories considering link flexibility was also investigated.

  2. Control issues related to bilateral teleoperation of long-reach, flexible manipulators

    SciTech Connect

    Love, L.J.

    1997-02-01

    A challenging problem presently being addressed by the Department of Energy (DOE) is the extraction of large volumes of hazardous waste from underground waste storage facilities. The nature of the material requires the use of robotic and teleoperated systems. Furthermore, the constraints of the storage tanks require the use of long reach manipulators. These robots are characterized by their large workspace and reduced mass. Unfortunately, this reduction in mass increases structural compliance, making these robots susceptible to vibration. Until recently, no attempt has been made to provide the operator any type of force reflection due to the compliance of the slave robot. This paper addresses the control of bilateral teleoperation systems that use long-reach, flexible manipulators. Analysis and experiments show that the compliance of the slave robot directly affects the stability of the teleoperation system. This study suggests that this may be controlled by increasing the damping on the master robot. However, this increase in target damping increases the energy an operator must exert during the execution of a task. A new teleoperation strategy adapts the target impedance of the master robot to variations in the identified impedance of the remote environment coupled to the slave robot. Experiments show increased performance due to a decrease in the energy the operator must provide during task execution.

  3. Input shaping filter methods for the control of structurally flexible, long-reach manipulators

    SciTech Connect

    Kwon, Dong-Soo; Hwang, Dong-Hwan; Babcock, S.M.; Burks, B.L.

    1993-11-01

    Within the Environmental Restoration and Waste Management Program of the US Department of Energy, the remediation of single-shell radioactive waste storage tanks is one of the areas that challenge state-of-the-art equipment and methods. Concepts that utilize long-reach manipulators are being seriously considered for this task. Due to high payload capacity and high length-to-cross-section ratio requirements, these long-reach manipulator systems are expected to exhibit significant structural flexibility. To avoid structural vibrations during operation, various types of shaping filter methods have been investigated. A robust notch filtering method and an impulse shaping method were used as simulation benchmarks. In addition to that, two very different approaches have been developed and compared. One new approach, referred to as a ``feedforward simulation filter,`` uses imbedded simulation with complete knowledge of the system dynamics. The other approach, ``fuzzy shaping method,`` employs a fuzzy logic method to modify the joint trajectory from the desired end-position trajectory without precise knowledge of the system dynamics.

  4. On stiffening cables of a long reach manipulator

    SciTech Connect

    Wang, S.L.; Santiago, P.

    1996-02-01

    A long reach manipulator will be used for waste remediation in large underground storage tanks. The manipulator`s slenderness makes it flexible and difficult to control. A low-cost and effective method to enhance the manipulator`s stiffness is proposed in this research by using suspension cables. These cables can also be used to accurately measure the position of the manipulator`s wrist.

  5. Key Design Requirements for Long-Reach Manipulators

    SciTech Connect

    Kwon, D.S.

    2001-01-01

    Long-reach manipulators differ from industrial robots and teleoperators typically used in the nuclear industry in that the aspect ratio (length to diameter) of links is much greater and link flexibility, as well as joint or drive train flexibility, is likely to be significant. Long-reach manipulators will be required for a variety of applications in the Environmental Restoration and Waste Management Program. While each application will present specific functional, kinematic, and performance requirements, an approach for determining the kinematic applicability and performance characteristics is presented, with a focus on waste storage tank remediation. Requirements are identified, kinematic configurations are considered, and a parametric study of link design parameters and their effects on performance characteristics is presented.

  6. Key design requirements for long-reach manipulators

    SciTech Connect

    Kwon, D.S.; March-Leuba, S.; Babcock, S.M.; Hamel, W.R.

    1993-09-01

    Long-reach manipulators differ from industrial robots and teleoperators typically used in the nuclear industry in that the aspect ratio (length to diameter) of links is much greater and link flexibility, as well as joint or drive train flexibility, is likely to be significant. Long-reach manipulators will be required for a variety of applications in the Environmental Restoration and Waste Management Program. While each application will present specific functional kinematic, and performance requirements an approach for determining the kinematic applicability and performance characteristics is presented, with a focus on waste storage tank remediation. Requirements are identified, kinematic configurations are considered, and a parametric study of link design parameters and their effects on performance characteristics is presented.

  7. Control of a long reach manipulator with suspension cables for waste storage tank remediation. Final report

    SciTech Connect

    Wang, S.L.

    1994-12-30

    A long reach manipulator will be used for waste remediation in large underground storage tanks. The manipulator`s slenderness makes it flexible and difficult to control. A low-cost and effective method to enhance the manipulator`s stiffness is proposed in this research by using suspension cables. These cables can also be used to accurately measure the position of the manipulator`s wrist.

  8. Defining a controller architecture for the Long-Reach Manipulator

    SciTech Connect

    Ford, W.E.

    1994-06-01

    To draft a procurement specification for the Long-Reach Manipulator (LRM), the benefits and limitations of the various robotic control system architectures available need to be determined. This report identifies and describes the advantages and potential disadvantages of using an open control system versus a closed (or proprietary) system, focusing on integration of interfaces for sensors, end effectors, tooling, and operator interfaces. In addition, the various controls methodologies of several recent systems are described. Finally, the reasons behind the recommendation to procure an open control system are discussed.

  9. First generation long-reach manipulator for retrieval of waste from Hanford single-shell tanks

    SciTech Connect

    Gibbons, P.W.; McDaniel, L.B.

    1994-10-01

    The US Department of Energy, Richland Operations Office, has established the Tank Waste Remediation System to resolve environmental and safety issues related to underground waste-storage tanks at the Hanford Site. The Tank Waste Remediation System has identified the use of an advanced-technology, long-reach manipulator system as a low-water-addition retrieval alternative to past-practice sluicing.

  10. Initial experiments on the end-point control of a 2-DOF long-reach elastic manipulator

    NASA Astrophysics Data System (ADS)

    Schmitz, Eric; Ramey, Madison

    1992-03-01

    To support the study of dynamics and control for long-reach, space-based manipulators, an experimental planar manipulator has been developed. The arm has a 15 ft reach with flexible links at the shoulder and elbow joints. The arm's equations of motion are derived with the aid of TREETOPS, a multibody dynamics analysis program. The resulting model is validated against experimental data. To serve as a base line for future work, two classically designed controllers have been implemented. One relies on sensors collocated with the joint actuators, while the other uses an end-point sensor measuring Cartesian displacements. Comparison of the controllers' experimental closed-loop responses demonstrate the performance improvements achievable using end-point position feedback; most notable is the more than two fold increase in control bandwidth. Experimental and simulation results also demonstrate the end-point controller's improved `Cartesian impedance.'

  11. Positional control strategies for a modular, long-reach, truss-type manipulator

    NASA Astrophysics Data System (ADS)

    Salerno, Robert James

    1993-01-01

    This dissertation proposes a new type of modular, long-reach, truss type manipulator. Variable Geometry Trusses (VGT's) are used to construct a reconfigurable manipulator system in which all primary members are loaded in pure tension or compression. Each module of the manipulator system is either a static truss link or one of several possible VGT actuators. This results in an extremely stiff and strong manipulator system with minimal overall weight. While many potential applications exist for this technology, the present work was largely motivated by the need for a robotic waste remediation system for underground radioactive waste storage tanks. This new manipulator system provides several advantages when used for this application. The reconfigurable nature of the proposed system allows the manipulator to be adapted on site to unforeseen conditions. Additionally, the kinematic redundancy of the manipulator ensures that solutions can be accomplished even in a highly obstructed workspace. The parallel structure of the truss modules enables the manipulator to be withdrawn in the event of a structural failure. Finally, of particular importance to this task, the open framework of the modules provide a passageway for waste conveyance or additionally, could act as a shielded conduit for control and power cabling. Kinematic analysis algorithms tailored to address the peculiarities of this new manipulator system have also been developed. In this work, the kinematic redundancy of the system is exploited to provide alternative solutions, to avoid numerical difficulties at singularities, or to avoid workspace obstacles. These issues are addressed through a combination of null space optimization procedures and order reduction methods. The null space optimization procedures are accomplished by extracting information from a full singular value decomposition of the jacobian matrix. This method is shown to converge quickly, even for systems with thirty or more degrees of freedom

  12. Application of a Novel Long-Reach Manipulator Concept to Asteroid Redirect Missions

    NASA Technical Reports Server (NTRS)

    Dorsey, John T.; Doggett, William R.; Jones, Thomas C.; King, Bruce D.

    2015-01-01

    A high priority mission currently being formulated by NASA is to capture all or part of an asteroid and return it to cis-lunar space for examination by an astronaut crew. Two major mission architectures are currently being considered: in the first (Mission Concept A), a spacecraft would rendezvous and capture an entire free flying asteroid (up to 14 meters in diameter), and in the second (Mission Concept B), a spacecraft would rendezvous with a large asteroid (which could include one of the Martian moons) and retrieve a boulder (up to 4 meters in diameter). A critical element of the mission is the system that will capture the asteroid or boulder material, enclose it and secure it for the return flight. This paper describes the design concepts, concept of operations, structural sizing and masses of capture systems that are based on a new and novel Tendon- Actuated Lightweight In-Space MANipulator (TALISMAN) general-purpose robotic system. Features of the TALISMAN system are described and the status of its technology development is summarized. TALISMAN-based asteroid material retrieval system concepts and concepts-of-operations are defined for each asteroid mission architecture. The TALISMAN-based capture systems are shown to dramatically increase operational versatility while reducing mission risk. Total masses of TALISMAN-based systems are presented, reinforcing the mission viability of using a manipulator-based approach for the asteroid redirect mission.

  13. Large planar maneuvers for articulated flexible manipulators

    NASA Technical Reports Server (NTRS)

    Huang, Jen-Kuang; Yang, Li-Farn

    1988-01-01

    An articulated flexible manipulator carried on a translational cart is maneuvered by an active controller to perform certain position control tasks. The nonlinear dynamics of the articulated flexible manipulator are derived and a transformation matrix is formulated to localize the nonlinearities within the inertia matrix. Then a feedback linearization scheme is introduced to linearize the dynamic equations for controller design. Through a pole placement technique, a robust controller design is obtained by properly assigning a set of closed-loop desired eigenvalues to meet performance requirements. Numerical simulations for the articulated flexible manipulators are given to demonstrate the feasibility and effectiveness of the proposed position control algorithms.

  14. Flexible manipulator control experiments and analysis

    NASA Technical Reports Server (NTRS)

    Yurkovich, S.; Ozguner, U.; Tzes, A.; Kotnik, P. T.

    1987-01-01

    Modeling and control design for flexible manipulators, both from an experimental and analytical viewpoint, are described. From the application perspective, an ongoing effort within the laboratory environment at the Ohio State University, where experimentation on a single link flexible arm is underway is described. Several unique features of this study are described here. First, the manipulator arm is slewed by a direct drive dc motor and has a rigid counterbalance appendage. Current experimentation is from two viewpoints: (1) rigid body slewing and vibration control via actuation with the hub motor, and (2) vibration suppression through the use of structure-mounted proof-mass actuation at the tip. Such an application to manipulator control is of interest particularly in design of space-based telerobotic control systems, but has received little attention to date. From an analytical viewpoint, parameter estimation techniques within the closed-loop for self-tuning adaptive control approaches are discussed. Also introduced is a control approach based on output feedback and frequency weighting to counteract effects of spillover in reduced-order model design. A model of the flexible manipulator based on experimental measurements is evaluated for such estimation and control approaches.

  15. Experimental verification of a large flexible manipulator

    NASA Technical Reports Server (NTRS)

    Lee, Jac Won; Huggins, James D.; Book, Wayne J.

    1988-01-01

    A large experimental lightweight manipulator would be useful for material handling, for welding, or for ultrasonic inspection of a large structure, such as an airframe. The flexible parallel link mechanism is designed for high rigidity without increasing weight. This constrained system is analyzed by singular value decomposition of the constraint Jacobian matrix. A verification of the modeling using the assumed mode method is presented. Eigenvalues and eigenvectors of the linearized model are compared to the measured system natural frequencies and their associated mode shapes. The modeling results for large motions are compared to the time response data from the experiments. The hydraulic actuator is verified.

  16. Dynamics modeling and adaptive control of flexible manipulators

    NASA Technical Reports Server (NTRS)

    Sasiadek, J. Z.

    1991-01-01

    An application of Model Reference Adaptive Control (MRAC) to the position and force control of flexible manipulators and robots is presented. A single-link flexible manipulator is analyzed. The problem was to develop a mathematical model of a flexible robot that is accurate. The objective is to show that the adaptive control works better than 'conventional' systems and is suitable for flexible structure control.

  17. Capture of free-flying payloads with flexible space manipulators

    NASA Technical Reports Server (NTRS)

    Komatsu, T.; Uenohara, M.; Iikura, S.; Miura, H.; Shimoyama, I.

    1989-01-01

    A recently developed control system for capturing free-flying payloads with flexible manipulators is discussed. Three essential points in this control system are, calculating optimal path, using a vision sensor for an external sensor, and controlling active vibration. Experimental results are shown using a planar flexible manipulator.

  18. Experiments in identification and control of flexible-link manipulators

    NASA Technical Reports Server (NTRS)

    Yurkovich, Stephen; Tzes, Anthony P.; Pacheco, Fernando E.

    1989-01-01

    Interest in the study of flexible-link manipulators for space-based applications has risen strongly in recent years. Moreover, numerous experimental results have appeared for the various problems in the modeling, identification and control of such systems. Nevertheless, relatively little literature has appeared involving laboratory verification of tuning controllers for certain types of realistic flexible-link manipulators. Specifically flexible-link manipulators which are required to maintain endpoint accuracy while manipulating loads that are possibly unknown and varying as they undergo disturbance effects from the environment and workspace. Endpoint position control of flexible-link manipulators in these areas are discussed, with laboratory setups consisting of one and two-link manipulators.

  19. Manipulator interactive design with interconnected flexible elements

    NASA Technical Reports Server (NTRS)

    Singh, R. P.; Likins, P. W.

    1983-01-01

    This paper describes the development of an analysis tool for the interactive design of control systems for manipulators and similar electro-mechanical systems amenable to representation as structures in a topological chain. The chain consists of a series of elastic bodies subject to small deformations and arbitrary displacements. The bodies are connected by hinges which permit kinematic constraints, control, or relative motion with six degrees of freedom. The equations of motion for the chain configuration are derived via Kane's method, extended for application to interconnected flexible bodies with time-varying boundary conditions. A corresponding set of modal coordinates has been selected. The motion equations are imbedded within a simulation that transforms the vector-dyadic equations into scalar form for numerical integration. The simulation also includes a linear, time-invariant controler specified in transfer function format and a set of sensors and actuators that interface between the structure and controller. The simulation is driven by an interactive set-up program resulting in an easy-to-use analysis tool.

  20. Control of a flexible bracing manipulator: Integration of current research work to realize the bracing manipulator

    NASA Technical Reports Server (NTRS)

    Kwon, Dong-Soo

    1991-01-01

    All research results about flexible manipulator control were integrated to show a control scenario of a bracing manipulator. First, dynamic analysis of a flexible manipulator was done for modeling. Second, from the dynamic model, the inverse dynamic equation was derived, and the time domain inverse dynamic method was proposed for the calculation of the feedforward torque and the desired flexible coordinate trajectories. Third, a tracking controller was designed by combining the inverse dynamic feedforward control with the joint feedback control. The control scheme was applied to the tip position control of a single link flexible manipulator for zero and non-zero initial condition cases. Finally, the contact control scheme was added to the position tracking control. A control scenario of a bracing manipulator is provided and evaluated through simulation and experiment on a single link flexible manipulator.

  1. Spatial-Operator Algebra For Flexible-Link Manipulators

    NASA Technical Reports Server (NTRS)

    Jain, Abhinandan; Rodriguez, Guillermo

    1994-01-01

    Method of computing dynamics of multiple-flexible-link robotic manipulators based on spatial-operator algebra, which originally applied to rigid-link manipulators. Aspects of spatial-operator-algebra approach described in several previous articles in NASA Tech Briefs-most recently "Robot Control Based on Spatial-Operator Algebra" (NPO-17918). In extension of spatial-operator algebra to manipulators with flexible links, each link represented by finite-element model: mass of flexible link apportioned among smaller, lumped-mass rigid bodies, coupling of motions expressed in terms of vibrational modes. This leads to operator expression for modal-mass matrix of link.

  2. Controlling Flexible Manipulators, an Experimental Investigation. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Hastings, Gordon Greene

    1986-01-01

    Lightweight, slender manipulators offer faster response and/or greater workspace range for the same size actuators than tradional manipulators. Lightweight construction of manipulator links results in increased structural flexibility. The increase flexibility must be considered in the design of control systems to properly account for the dynamic flexible vibrations and static deflections. Real time control of the flexible manipulator vibrations are experimentally investigated. Models intended for real-time control of distributed parameter system such as flexible manipulators rely on model approximation schemes. An linear model based on the application of Lagrangian dynamics to a rigid body mode and a series of separable flexible modes is examined with respect to model order requirements, and modal candidate selection. Balanced realizations are applied to the linear flexible model to obtain an estimate of appropriate order for a selected model. Describing the flexible deflections as a linear combination of modes results in measurements of beam state, which yield information about several modes. To realize the potential of linear systems theory, knowledge of each state must be available. State estimation is also accomplished by implementation of a Kalman Filter. State feedback control laws are implemented based upon linear quadratic regulator design.

  3. Fuzzy Control of Flexible-Link Manipulators: A Review

    NASA Technical Reports Server (NTRS)

    Akbarzadeh-T, M.-R.; Quintana, S.; Jamshidi, M.

    1998-01-01

    Several recent research efforts are reviewed here which have applied fuzzy logic in control of flexible-link manipulators. A flexible robot is a distributed parameter system represented by complex nonlinear dynamics, its actuator and the control parameters are non-colocated, and lastly, unstructured/unknown parameters play a significant role in model dynamics of a flexible robot operating in the real world. As a result, control of flexible robots is considered a promising area for application of intelligent control methodologies such as fuzzy logic, genetic algorithms, and neural networks.

  4. Vibration control of a manipulator tip on a flexible body

    NASA Technical Reports Server (NTRS)

    Xu, J.; Bainum, P. M.; Li, F.

    1992-01-01

    Vibration control of a rigid manipulator tip on a main flexible uniform beam is examined. It is proposed to add a compensator between the manipulator and the beam to rotate and extend/retrieve the manipulator during the control period. The 2D station-keeping maneuvers within the linear range without gravity and damping are considered. The compensatory open-loop control law, which depends on the amplitudes of the beam's flexible deformations at the connection joint, is synthesized using linear quadratic regulator techniques. After introducing the compensatory control into the system, system control is still stable, and the tip coordinates of the manipulator can be made to closely follow the rigid beam motion, which is assumed to be a desired motion.

  5. Direct model reference adaptive control of a flexible robotic manipulator

    NASA Technical Reports Server (NTRS)

    Meldrum, D. R.

    1985-01-01

    Quick, precise control of a flexible manipulator in a space environment is essential for future Space Station repair and satellite servicing. Numerous control algorithms have proven successful in controlling rigid manipulators wih colocated sensors and actuators; however, few have been tested on a flexible manipulator with noncolocated sensors and actuators. In this thesis, a model reference adaptive control (MRAC) scheme based on command generator tracker theory is designed for a flexible manipulator. Quicker, more precise tracking results are expected over nonadaptive control laws for this MRAC approach. Equations of motion in modal coordinates are derived for a single-link, flexible manipulator with an actuator at the pinned-end and a sensor at the free end. An MRAC is designed with the objective of controlling the torquing actuator so that the tip position follows a trajectory that is prescribed by the reference model. An appealing feature of this direct MRAC law is that it allows the reference model to have fewer states than the plant itself. Direct adaptive control also adjusts the controller parameters directly with knowledge of only the plant output and input signals.

  6. Force control for robotic manipulators with structurally flexible links

    NASA Astrophysics Data System (ADS)

    Latornell, Douglas John

    1992-01-01

    This thesis reports on the development of strategies for the control of contact forces exerted by a structurally flexible robotic manipulator on surfaces in its working environment. The controller is based on a multivariable, explicitly adaptive, long range predictive control algorithm. A static equilibrium bias term which is particularly applicable to the contact force control problem has been incorporated into the control algorithm cost function. A general formulation for the discrete time domain characteristic polynomial of the closed loop system has been derived and shown useful in tuning the controller. Kinematic and dynamic models of a robotic manipulator with structurally flexible links interacting with its working environment are derived. These models include inertia and damping effects in the contact dynamics in addition to the contact stiffness employed in most previous work. Linear analyses of the dynamic models for a variety of manipulator configurations reveal that the controlled variable, the contact force, is dominated by different open loop modes of the system depending on the effective stiffness of the contacting surfaces. This result has important implications for the selection of the controller parameters. The performance of the controller has been evaluated using computer simulation. A special purpose simulation program, TWOFLEX, which includes the dynamics models of the manipulator and the environment as well as the control algorithm was developed during the research. The configurations investigated using the simulation include a single flexible manipulator link, two link manipulators with both rigid and flexible links, and a two link prototype model of the Mobile Servicing System (MSS) manipulator for the proposed Space Station Freedom. The results show that the controller can be tuned to provide fast contact force step responses with minimal overshoot and zero steady-state error. The problem of maintaining control through the discontinuous

  7. Analytical dynamic solution of a flexible cable-suspended manipulator

    NASA Astrophysics Data System (ADS)

    Bamdad, Mahdi

    2013-12-01

    Cable-suspended manipulators are used in large scale applications with, heavy in weight and long in span cables. It seems impractical to maintain cable assumptions of smaller robots for large scale manipulators. The interactions among the cables, platforms and actuators can fully evaluate the coupled dynamic analysis. The structural flexibility of the cables becomes more pronounced in large manipulators. In this paper, an analytic solution is provided to solve cable vibration. Also, a closed form solution can be adopted to improve the dynamic response to flexibility. The output is provided by the optimal torque generation subject to the actuator limitations in a mechatronic sense. Finally, the performance of the proposed algorithm is examined through simulations.

  8. Experiments in identification and control of flexible-link manipulators

    NASA Technical Reports Server (NTRS)

    Yurkovich, Stephen; Tzes, Anthony P.

    1990-01-01

    A report is presented on an ongoing effort for end-point position control of flexible-link manipulators under realistic conditions in laboratory setups consisting of one- and two-link manipulators. The authors treat modeling, identification, and control of flexible-link manipulators that are required to carry payloads, possibly unknown and varying, while undergoing disturbance effects from the environments and the workspace. The various identification and control techniques being investigated are summarized, with emphasis on the ability of the controller to adjust to changes in dynamics, payload, and working environment. It is found that time-domain methods offer identified model structures that are readily available for control design, whereas frequency-domain methods, particularly the time-varying transfer function estimation approach developed for this application, are more desirable when rapid controller tuning is required.

  9. Remote Manipulation of Droplets on a Flexible Magnetically Responsive Film

    PubMed Central

    Kim, Jeong Hun; Kang, Seong Min; Lee, Byung Jun; Ko, Hangil; Bae, Won-Gyu; Suh, Kahp Yang; Kwak, Moon Kyu; Jeong, Hoon Eui

    2015-01-01

    The manipulation of droplets is used in a wide range of applications, from lab-on-a-chip devices to bioinspired functional surfaces. Although a variety of droplet manipulation techniques have been proposed, active, fast and reversible manipulation of pure discrete droplets remains elusive due to the technical limitations of previous techniques. Here, we describe a novel technique that enables active, fast, precise and reversible control over the position and motion of a pure discrete droplet with only a permanent magnet by utilizing a magnetically responsive flexible film possessing actuating hierarchical pillars on the surface. This magnetically responsive surface shows reliable actuating capabilities with immediate field responses and maximum tilting angles of ~90°. Furthermore, the magnetic responsive film exhibits superhydrophobicity regardless of tilting angles of the actuating pillars. Using this magnetically responsive film, we demonstrate active and reversible manipulation of droplets with a remote magnetic force. PMID:26648418

  10. Boundary feedback stabilisation of a flexible robotic manipulator with constraint

    NASA Astrophysics Data System (ADS)

    He, Wei; Sun, Chen

    2016-03-01

    In this paper, the flexible robotic manipulator is modelled as a distributed parameter system, represented by a group of partial differential equations and ordinary differential equations. Control is designed at the boundary of the robotic manipulator based on integral-barrier Lyapunov function to suppress the vibration of the elastic deflection and track the desired angular position. With the proposed boundary control, the manipulator can be driven to the desired set-point with angular position and elastic deflection stay under the former setting constraint. Uniformed boundedness of the closed-loop system under the unknown time-varying disturbance is achieved. Stability analysis of the closed-loop system is given by employing the Lyapunov stability theory. Simulation results illustrate the effectiveness of the proposed boundary controller for ensuring output constraint and suppressing vibrations.

  11. Modelling the Shuttle Remote Manipulator System: Another flexible model

    NASA Technical Reports Server (NTRS)

    Barhorst, Alan A.

    1993-01-01

    High fidelity elastic system modeling algorithms are discussed. The particular system studied is the Space Shuttle Remote Manipulator System (RMS) undergoing full articulated motion. The model incorporates flexibility via a methodology the author has been developing. The technique is based in variational principles, so rigorous boundary condition generation and weak formulations for the associated partial differential equations are realized, yet the analyst need not integrate by parts. The methodology is formulated using vector-dyad notation with minimal use of tensor notation, therefore the technique is believed to be affable to practicing engineers. The objectives of this work are as follows: (1) determine the efficacy of the modeling method; and (2) determine if the method affords an analyst advantages in the overall modeling and simulation task. Generated out of necessity were Mathematica algorithms that quasi-automate the modeling procedure and simulation development. The project was divided into sections as follows: (1) model development of a simplified manipulator; (2) model development of the full-freedom RMS including a flexible movable base on a six degree of freedom orbiter (a rigid-body is attached to the manipulator end-effector); (3) simulation development for item 2; and (4) comparison to the currently used model of the flexible RMS in the Structures and Mechanics Division of NASA JSC. At the time of the writing of this report, items 3 and 4 above were not complete.

  12. Numerical simulation of mechanisms and manipulator robots with flexible links and flexible joints

    NASA Astrophysics Data System (ADS)

    Gong, D.

    1995-01-01

    This thesis deals with numerical simulation of mechanical systems like mechanisms and manipulator robots. The mechanical system may be considered in a two or three dimensional space, may have electrical machines, and may contain flexible links and flexible joints. Methods and algorithms to perform static analysis, kinematic analysis, dynamic analysis, linearization of nonlinear systems, periodic solution of periodically forced systems and control simulation of robots have been applied. A finite element method is used to get the mathematical model for a mechanical system. Friendly interfaces for pre- and post-processing have been designed by using X Window on Sun workstations. An integrated program network and data base has been applied in the software system SPACAR. For the simulation of robots with flexible links and flexible joints, two linearization methods have been studied: the variational linearization method and the feedback linearization method. Numerical examples for simulation of robots with flexible links and flexible joints have been presented to show the elegance and powerfulness of the introduced methods and the designed software system.

  13. Experimental investigations of the effects of cutting angle on chattering of a flexible manipulator

    NASA Technical Reports Server (NTRS)

    Lew, J.; Huggins, J.; Magee, D.; Book, W.

    1991-01-01

    When a machine tool is mounted at the tip of a robotic manipulator, the manipulator becomes more flexible (the natural frequencies are lowered). Moreover, for a given flexible manipulator, its compliance will be different depending on feedback gains, configurations, and direction of interest. Here, the compliance of a manipulator is derived analytically, and its magnitude is represented as a compliance ellipsoid. Then, using a two-link flexible manipulator with an abrasive cut off saw, the experimental investigation shows that the chattering varies with the saw cutting angle due to different compliance. The main work is devoted to finding a desirable cutting angle which reduces the chattering.

  14. A Robotic System for Actively Stiffening Flexible Manipulators

    PubMed Central

    Loschak, Paul M.; Burke, Stephen F.; Zumbro, Emiko; Forelli, Alexandra R.; Howe, Robert D.

    2015-01-01

    A system for actively changing the stiffness of a long, thin, flexible robotic manipulator has been designed for cardiologists to use in a range of diagnosis and treatment procedures. Low-stiffness manipulators, such as catheters, are ideal for steering through vasculature with low risk of tissue injury. However, such instruments are not well-suited for applying force to tissue. The proposed system solves this problem by using a series of bead-shaped vertebrae containing pull wires to actively change the stiffness of the catheter, similar to gooseneck surgical retractors. Individual wires steer the catheter to a desired location. All wires are then tensioned to create friction between each vertebra and prevent sliding, therefore resisting motion. While this design concept has been implemented manually in various settings for decades, fine robotic control of the friction and stiffness of the system relies on a thorough understanding of the friction properties between vertebral segments. We have developed an analytical model to understand the interactions between vertebrae and determine the relationships between system parameters and the overall stiffness of the catheter. Experiments validated the calculations from the model and the functionality of the system by applying known loads to the tip of the catheter and measuring the catheter displacement. The catheter stiffness was measured to range from 100 N/m to 800 N/m, which is sufficient for performing many surgical tasks on tissue. This system can be useful in minimally invasive procedures involving direct instrument contact with tissue by improving accuracy, safety, and work flow. PMID:26709364

  15. Generalized finite element dynamic modelling and simulation for flexible robot manipulators

    NASA Astrophysics Data System (ADS)

    Zhou, Feng

    1993-01-01

    The finite element approach is used to model multi-link flexible robotic manipulators. The kinematic character of flexible manipulators is analyzed using body-fixed and link element attached coordinates. Dynamic equations for flexible robot manipulators are then derived. The position of each point on the link is expressed using a transformation matrix, and the kinetic and potential energy for each element is computed and summed over all the elements. The Lagrangian formulation is applied to set up the dynamic equations of the system. Computational simulations are performed on single- and two-link manipulators with and without torque to check the validity and correctness of the derived dynamic equations. The Runge-Kutta method is used to solve the dynamic equations for flexible manipulators on which all the joints are revolute.

  16. Initial experiments in end-point control of a flexible, two-link manipulator

    NASA Astrophysics Data System (ADS)

    Whalen, Mark David

    1992-11-01

    A two-link, flexible manipulator has been designed and constructed to study en-point vibration and control problems. The manipulator has two activated rotary joints and operates in the horizontal plane. It has been designed for minimal join flexibility and very flexible links. Further, the links have been designed so that the first natural frequencies of each link are very close. The manipulator vibratory characteristics have been quantified through a series of frequency response and modal analysis tests using external excitation sources as well as internal excitation supplied by the manipulator joint actuators. By performing tests for various manipulator postures, the vibratory responses of the manipulator links are shown to become uncoupled as the elbow angle approaches 90 degrees. Further, the internal excitation tests have shown that some vibratory modes cannot be excited by the rotary joint actuators. An analytical model of the manipulator has been developed using Kane's equations with Bernoulli-Euler assumed modes. Because the modal analysis has shown that the manipulator vibratory response varies with the elbow joint angle, assumed modes of the individual links are used to model flexibility effects rather than manipulator assumed modes. Unfortunately, no experimental results suitable for confirming the analytical model are available yet. A PID baseline controller of the manipulator is presented with experimental results. Recommendations for improving the PID controller are presented. Alternate controller schemes are presented and discussed.

  17. Beam rider for an Articulated Robot Manipulator (ARM) accurate positioning of long flexible manipulators

    NASA Technical Reports Server (NTRS)

    Malachowski, M. J.

    1990-01-01

    Laser beam positioning and beam rider modules were incorporated into the long hollow flexible segment of an articulated robot manipulator (ARM). Using a single laser beam, the system determined the position of the distal ARM endtip, with millimetric precision, in six degrees of freedom, at distances of up to 10 meters. Preliminary designs, using space rated technology for the critical systems, of a two segmented physical ARM, with a single and a dual degree of freedom articulation, were developed, prototyped, and tested. To control the positioning of the physical ARM, an indirect adaptive controller, which used the mismatch between the position of the laser beam under static and dynamic conditions, was devised. To predict the behavior of the system and test the concept, a computer simulation model was constructed. A hierarchical artificially intelligent real time ADA operating system program structure was created. The software was designed for implementation on a dedicated VME bus based Intel 80386 administered parallel processing multi-tasking computer system.

  18. Back-stepping control of two-link flexible manipulator based on an extended state observer

    NASA Astrophysics Data System (ADS)

    Yang, Hongjiu; Yu, Yang; Yuan, Yuan; Fan, Xiaozhao

    2015-11-01

    In this paper, we consider trajectory tracking control of a two-link flexible manipulator model in space. Two variables of joint angle and elastic deformation are partly decoupled by a nonlinear decoupling feedback control method. An extended state observer is introduced to estimate nonlinear terms of the two-link flexible manipulator system. Based on a back-stepping method, a nonlinear controller is designed for the flexible manipulator system. Finally, some simulation results are given to demonstrate the effectiveness of the developed techniques in this paper.

  19. Centralized, decentralized, and independent control of a flexible manipulator on a flexible base

    NASA Technical Reports Server (NTRS)

    Li, Feiyue; Bainum, Peter M.; Xu, Jianke

    1991-01-01

    The dynamics and control of a flexible manipulator arm with payload mass on a flexible base in space are considered. The controllers are provided by one torquer at the center of the base and one torquer at the connection joint of the robot and the base. The nonlinear dynamics of the system is modeled by applying the finite element method and Lagrangian formula. Three control strategies are considered and compared, i.e., centralized control, decentralized control, and independent control. All these control designs are based on the linear quadratic regulator theory. A mathematical decomposition is used in the decentralization process so that the coupling between the subsystems is weak, while a physical decomposition is used in the independent control design process. For both the decentralized and the independent controls, the stability of the overall linear system is checked before a numerical simulations is initiated. Two numerical examples show that the response of the independent control system are close to those of the centralized control system, while the responses of the decentralized control system are not.

  20. Dynamic analysis and control of lightweight manipulators with flexible parallel link mechanisms

    NASA Technical Reports Server (NTRS)

    Lee, Jeh Won

    1991-01-01

    The flexible parallel link mechanism is designed for increased rigidity to sustain the buckling when it carries a heavy payload. Compared to a one link flexible manipulator, a two link flexible manipulator, especially the flexible parallel mechanism, has more complicated characteristics in dynamics and control. The objective of this research is the theoretical analysis and the experimental verification of dynamics and control of a two link flexible manipulator with a flexible parallel link mechanism. Nonlinear equations of motion of the lightweight manipulator are derived by the Lagrangian method in symbolic form to better understand the structure of the dynamic model. A manipulator with a flexible parallel link mechanism is a constrained dynamic system whose equations are sensitive to numerical integration error. This constrained system is solved using singular value decomposition of the constraint Jacobian matrix. The discrepancies between the analytical model and the experiment are explained using a simplified and a detailed finite element model. The step response of the analytical model and the TREETOPS model match each other well. The nonlinear dynamics is studied using a sinusoidal excitation. The actuator dynamic effect on a flexible robot was investigated. The effects are explained by the root loci and the Bode plot theoretically and experimentally. For the base performance for the advanced control scheme, a simple decoupled feedback scheme is applied.

  1. Maneuver and vibration control of flexible manipulators using variable-speed control moment gyros

    NASA Astrophysics Data System (ADS)

    Hu, Quan; Zhang, Jingrui

    2015-08-01

    In this paper, the variable-speed control moment gyros (VS-CMGs) are adopted as actuators for vibration suppression of space flexible manipulators. They are directly mounted on the flexible links of the manipulator. Such system can be viewed as a flexible multibody system in chain topology actuated by both joint motors and VS-CMGs. We first develop a general approach for establishing the system equations of motion through Kane's method. Then, two controllers are designed for trajectory tracking and vibration suppression: one is an inverse dynamics control, whereas the other is based on the singular perturbation method. The proposed two control strategies are applied to a free-flying platform with a flexible manipulator. Sample numerical results show that the VS-CMGs can significantly suppress the induced vibration of the flexible links during the large angle maneuver.

  2. Force and motion control of a constrained flexible manipulator

    NASA Astrophysics Data System (ADS)

    Hu, Fon-Lin

    1992-01-01

    This dissertation reports the results of a comprehensive research study on the combined joint motion control, vibration control, and force control of a constrained rigid-flexible robot arm. An efficient and accurate approach to modeling for controller design is provided. Both regulation and tracking problems are considered, and a modified version of a Corless-Leitmann controller is developed. Experimental studies, which demonstrate the effectiveness of the proposed methods, are presented. In this work, the dynamic modeling of a constrained spherical coordinate robot arm, whose last link is very flexible, is studied for the purpose of combined force and motion control. The model is derived using a consistent modeling procedure which accounts for the axial force effects due to contract, and the coupling due to the effects of flexible motions on the rigid body motions. These effects are shown to be important in the prediction of the vibration frequencies. Galerkin's method is employed for spatial discretization of the flexible link deflections. A convergence study is presented to evaluate the appropriateness of the spatial approximating functions and to determine the number of modes required for obtaining accurate simulation results. Linear control design methods are shown to be adequate for solving the problem of hybrid force and position regulation for the constrained flexible robot arm. However, nonlinear control strategies show advantages (i.e., good response of the joint motion and contact force, and small magnitude of the structural vibration) in the tracking control of motion and force. A modified Corless-Leitmann controller is presented to enhance the control of the flexible motion using only joint actuators. Finally, an experimental implementation is used to validate the proposed controller designs, to assess the merit of measuring and feeding back the flexible motion and the contact force, and to evaluate the feasibility of combined force and motion control

  3. Remote manipulator system flexibility analysis program: Mission planning, mission analysis, and software formulation

    NASA Technical Reports Server (NTRS)

    Kumar, L.

    1978-01-01

    A computer program is described for calculating the flexibility coefficients as arm design changes are made for the remote manipulator system. The coefficients obtained are required as input for a second program which reduces the number of payload deployment and retrieval system simulation runs required to simulate the various remote manipulator system maneuvers. The second program calculates end effector flexibility and joint flexibility terms for the torque model of each joint for any arbitrary configurations. The listing of both programs is included in the appendix.

  4. On dynamics and control of multi-link flexible space manipulators

    NASA Technical Reports Server (NTRS)

    Gawronski, W.; Ih, C.-H. C.; Wang, S. J.

    1990-01-01

    In this paper dynamics, inverse dynamics, and control problems for multi-link flexible space manipulators are presented. In deriving the flexible manipulator dynamics the following are assumed: flexible deformations are relatively small; angular rates of the links are much smaller than their fundamental frequencies; nonlinear terms (centrifugal and Coriolis forces) in the flexible manipulator model are the same as those in the rigid body model. These assumptions are reasonable for large space manipulators, such as the space crane. Flexible displacements are measured with respect to the rigid body configuration, for which a linear time-varying system is obtained. The inverse dynamics problem consists of determination of joint torques, given tip trajectory, such that joint angles in flexible configuration are equal to the angles in the rigid body configuration. The manipulator control system consists of the feedforward compensation and feedback control loops. Simulation results of a two-link space crane with large payload show that the performance of this linearized dynamics and control approach is reasonable and robust subject to parameter variations during slew operations.

  5. Identification and control for a manipulator with two flexible links

    NASA Technical Reports Server (NTRS)

    Yurkovich, Stephen; Hillsley, Kenneth L.; Tzes, Anthony P.

    1990-01-01

    The authors investigate the effectiveness of an online identification scheme for tracking the modal frequencies of a two-link flexible mechanism executing large-angle movements and carrying an unknown payload. A decentralized, gain-scheduled, adaptive control scheme is employed in conjunction with the identification scheme in order to illustrate the feasibility of online controller adjustment for endpoint position control in terms of vibration suppression after large-angle movements. Motivation for adopting the autoregressive-moving-average-model perspective is based on the convenient representation for online controller tuning and on the assumption that flexibility dynamics, for small deflections after a nonlinear large-angle motion, exhibit linear behavior. Experimental results are presented for a two-link planar mechanism in which both links are very flexible.

  6. Full monitoring for long-reach TWDM passive optical networks.

    PubMed

    Cen, Min; Chen, Jiajia; Moeyaert, Véronique; Mégret, Patrice; Wuilpart, Marc

    2016-07-11

    This paper presents a novel and simple fiber monitoring system based on multi-wavelength transmission-reflection analysis for long-reach time and wavelength division multiplexing passive optical networks. For the first time, the full localization functionality of long-reach passive optical networks is possible with the proposed monitoring scheme, including supporting fault detection, identification, and localization in both feeder and distribution fiber segments. By measuring the transmitted and reflected/backscattered optical powers launched by an unmodulated continuous-wave optical source, the proposed solution is able to supervise the network with good spatial accuracy, a high detection speed and a low impact on data traffic. Both the theoretical analysis and experimental validation show that the proposed scheme is capable of providing an accurate fault monitoring functionality for long-reach time and wavelength division multiplexing passive optical networks. PMID:27410849

  7. Dynamic Analysis and Control of Lightweight Manipulators with Flexible Parallel Link Mechanisms. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Lee, Jeh Won

    1990-01-01

    The objective is the theoretical analysis and the experimental verification of dynamics and control of a two link flexible manipulator with a flexible parallel link mechanism. Nonlinear equations of motion of the lightweight manipulator are derived by the Lagrangian method in symbolic form to better understand the structure of the dynamic model. The resulting equation of motion have a structure which is useful to reduce the number of terms calculated, to check correctness, or to extend the model to higher order. A manipulator with a flexible parallel link mechanism is a constrained dynamic system whose equations are sensitive to numerical integration error. This constrained system is solved using singular value decomposition of the constraint Jacobian matrix. Elastic motion is expressed by the assumed mode method. Mode shape functions of each link are chosen using the load interfaced component mode synthesis. The discrepancies between the analytical model and the experiment are explained using a simplified and a detailed finite element model.

  8. Dynamic analysis of a spatial robot manipulator with a flexible prismatic link

    NASA Astrophysics Data System (ADS)

    Liu, Qiukui

    1993-01-01

    A geometrically nonlinear finite element dynamic model for large deflections is developed for a three-dimensional, three-link robot manipulator with a flexible prismatic link fabricated from advanced composite materials operated at higher speeds or used for the waste storage tank cleanup and space station applications. A unique technique for the finite element modeling of a flexible sliding link is developed. The effect of geometric nonlinearity on the dynamic behavior of the flexible robot manipulator is evaluated. The coupling effect between the rigid body motion and the elastic motion on the dynamic behavior of the robot manipulator is investigated. This work also investigates the effect of material damping of the flexible composite laminated link with different lamination schemes and the effect of the axial inertial force of the flexible link on its transverse oscillations. In particular, the instability effect of the axial rigid body motion of the flexible link on its transverse oscillations is evaluated. A physical interpretation of the parametric instability induced by the axial rigid body sinusoidal motion is given. The study shows that the coupling effect increases the transverse oscillation frequency of the flexible link, that the transverse oscillation will be unstable if the axial sinusoidal motion frequency is close to twice any transverse oscillation frequency of the flexible link, that the transverse oscillation frequency of the flexible link can be increased significantly by geometric nonlinearity, and that the axial inertial force has a stiffening effect on the dynamic behavior of the flexible link. These results can be used to further improve the design of the flexible robotic system.

  9. Anatomy of an experimental two-link flexible manipulator under end-point control

    NASA Technical Reports Server (NTRS)

    Oakley, Celia M.; Cannon, Robert H., Jr.

    1990-01-01

    The design and experimental implementation of an end-point controller for two-link flexible manipulators are presented. The end-point controller is based on linear quadratic Gaussian (LQG) theory and is shown to exhibit significant improvements in trajectory tracking over a conventional controller design. To understand the behavior of the manipulator structure under end-point control, a strobe sequence illustrating the link deflections during a typical slew maneuver is included.

  10. Accurate positioning of long, flexible ARM's (Articulated Robotic Manipulator)

    NASA Technical Reports Server (NTRS)

    Malachowski, Michael J.

    1988-01-01

    An articulated robotic manipulator (ARM) system is being designed for space applications. Work being done on a concept utilizing an infinitely stiff laser beam for position reference is summarized. The laser beam is projected along the segments of the ARM, and the position is sensed by the beam rider modules (BRM) mounted on the distal ends of the segments. The BRM concept is the heart of the system. It utilizes a combination of lateral displacements and rotational and distance measurement sensors. These determine the relative position of the two ends of the segments with respect to each other in six degrees of freedom. The BRM measurement devices contain microprocessor controlled data acquisition and active positioning components. An indirect adaptive controller is used to accurately control the position of the ARM.

  11. The effect of inertial coupling in the dynamics and control of flexible robotic manipulators

    NASA Technical Reports Server (NTRS)

    Tesar, Delbert; Curran, Carol Cockrell; Graves, Philip Lee

    1988-01-01

    A general model of the dynamics of flexible robotic manipulators is presented, including the gross motion of the links, the vibrations of the links and joints, and the dynamic coupling between the gross motions and vibrations. The vibrations in the links may be modeled using lumped parameters, truncated modal summation, a component mode synthesis method, or a mixture of these methods. The local link inertia matrix is derived to obtain the coupling terms between the gross motion of the link and the vibrations of the link. Coupling between the motions of the links results from the kinematic model, which utilizes the method of kinematic influence. The model is used to simulate the dynamics of a flexible space-based robotic manipulator which is attached to a spacecraft, and is free to move with respect to the inertial reference frame. This model may be used to study the dynamic response of the manipulator to the motions of its joints, or to externally applied disturbances.

  12. Development of a modular integrated control architecture for flexible manipulators. Final report

    SciTech Connect

    Burks, B.L.; Battiston, G.

    1994-12-08

    In April 1994, ORNL and SPAR completed the joint development of a manipulator controls architecture for flexible structure controls under a CRADA between the two organizations. The CRADA project entailed design and development of a new architecture based upon the Modular Integrated Control Architecture (MICA) previously developed by ORNL. The new architecture, dubbed MICA-II, uses an object-oriented coding philosophy to provide a highly modular and expandable architecture for robotic manipulator control. This architecture can be readily ported to control of many different manipulator systems. The controller also provides a user friendly graphical operator interface and display of many forms of data including system diagnostics. The capabilities of MICA-II were demonstrated during oscillation damping experiments using the Flexible Beam Experimental Test Bed at Hanford.

  13. Sensitivity analysis of flexible joint nonholonomic wheeled mobile manipulator in singular configuration

    NASA Astrophysics Data System (ADS)

    Korayem, A. H.; Azimirad, V.; Binabaji, H.; Korayem, M. H.

    2012-03-01

    This paper proposes a method for decreasing jerk and increasing Maximum Allowable Load (MAL) of nonholonomic Wheeled Mobile Manipulator (WMM) considering flexibility of joints in singular conditions. The full dynamic model of nonholonomic WMM contains simultaneous operation of mobile base and manipulator with joint flexibility (in wheels and manipulator) which is presented here. The problem is formulated in terms of the optimal control which leads to a two point boundary value problem. Then Sobol's sensitivity analysis method is applied to determine the optimal values of flexible joint constants subject to the jerk minimization. To illustrate the proposed method, two categories of conditions are considered: conditions containing non-singular configuration and the singular conditions. An example is explained for non-singular condition of nonholonomic WMM in presence of obstacle in which a complex path is generated but there is no singularity in robot configuration. Some examples of occurring singular configuration in final point and moving boundary condition is also presented. The results show that flexibility of the joints near to singular configuration normalizes the sudden movement and jerk implied to actuators. That is why using a rotational spring with a low stiffness coefficient could be helpful to decrease the high jerk and increase the maximum allowable load in mobile robots.

  14. Long-Reach Transmission Characteristics of Tunable External Cavity Laser.

    PubMed

    Oh, Su Hwan; Yoon, Ki-Hong; Cho, Seung-Hyun; Seo, Jun-Kyu

    2015-10-01

    We report the transmission capability of a tunable external cavity laser (T-ECL) that utilizes a super-luminescent diode (SLD) and a polymer Bragg reflector (PBR) operating with a direct modulation of 2.5 Gb/s for a light source of a long-reach wavelength division multiplexed-passive optical net- work (WDM-PON). The T-ECL successfully operated at an ambient temperature of -20 °C to 70 °C when employing a cooled SLD. A tuning range of 12-nm is achieved with a tuning power of lower than 80 mW. A side mode suppression ratio of more than 35 dB was obtained for the whole tuning range. The linewidth of the lasing spectrum is less than 0.1 nm at 20 dB from the peak power. The transmission performance of the T-ECL, including an optical bandpass filter (OBPF), is better than that of the T-ECL excluding an OBPF for a long-reach transmission over 80 km of single mode fiber (SMF). The power penalty of the T-ECL is less than 1.4 dB when using an OBPF for an 80-km transmission. PMID:26726351

  15. Performance limitations of joint variable-feedback controllers due to manipulator structural flexibility

    NASA Technical Reports Server (NTRS)

    Cetinkunt, Sabri; Book, Wayne J.

    1990-01-01

    The performance limitations of manipulators under joint variable-feedback control are studied as a function of the mechanical flexibility inherent in the manipulator structure. A finite-dimensional time-domain dynamic model of a two-link two-joint planar manipulator is used in the study. Emphasis is placed on determining the limitations of control algorithms that use only joint variable-feedback information in calculations of control decisions, since most motion control systems in practice are of this kind. Both fine and gross motion cases are studied. Results for fine motion agree well with previously reported results in the literature and are also helpful in explaining the performance limitations in fast gross motions.

  16. Effects of joint controller on analytical modal analysis of rotational flexible manipulator

    NASA Astrophysics Data System (ADS)

    Chu, Ming; Zhang, Yanheng; Chen, Gang; Sun, Hanxu

    2015-04-01

    Modal analysis is a fundamental and important task for modeling and control of the flexible manipulator. However, almost all of the traditional modal analysis methods view the flexible manipulator as a pure mechanical structure and neglect feedback action of joint controller. In order to study the effects of joint controller on the modal analysis of rotational flexible manipulator, a closed-loop analytical modal analysis method is proposed. Firstly, two exact boundary constraints, namely servo feedback constraint and bending moment constraint, are derived to solve the vibration partial differential equation. It is found that the stiffness and damping gains of joint controller are both included in the boundary conditions, which lead to an unconventional secular term. Secondly, analytical algorithm based on Ritz approach is developed by using Laplace transform and complex modal approach to obtain the natural frequencies and mode shapes. And then, the numerical simulations are performed and the computational results show that joint controller has pronounced influence on the modal parameters: joint controller stiffness reduces the natural frequency, while joint controller damping makes the shape phase non-zero. Furthermore, the validity of the presented conclusion is confirmed through experimental studies. These findings are expected to improve the performance of dynamics simulation systems and model-based controllers.

  17. Hardware interface for isolation of vibrations in flexible manipulators: Development and applications

    NASA Technical Reports Server (NTRS)

    Manouchehri, Davoud; Lindsay, Thomas; Ghosh, David

    1994-01-01

    NASA's Langley Research Center (LaRC) is addressing the problem of isolating the vibrations of the Shuttle remote manipulator system (RMS) from its end-effector and/or payload by modeling an RMS flat-floor simulator with a dynamic payload. Analysis of the model can lead to control techniques that will improve the speed, accuracy, and safety of the RMS in capturing satellites and eventually facilitate berthing with the space station. Rockwell International Corporation, also involved in vibration isolation, has developed a hardware interface unit to isolate the end-effector from the vibrations of an arm on a Shuttle robotic tile processing system (RTPS). To apply the RTPS isolation techniques to long-reach arms like the RMS, engineers have modeled the dynamics of the hardware interface unit with simulation software. By integrating the Rockwell interface model with the NASA LaRC RMS simulator model, investigators can study the use of a hardware interface to isolate dynamic payloads from the RMS. The interface unit uses both active and passive compliance and damping for vibration isolation. Thus equipped, the RMS could be used as a telemanipulator with control characteristics for capture and berthing operations. The hardware interface also has applications in industry.

  18. Modeling and control of a hydraulically actuated flexible-prismatic link robot

    SciTech Connect

    Love, L.; Kress, R.; Jansen, J.

    1996-12-01

    Most of the research related to flexible link manipulators to date has focused on single link, fixed length, single plane of vibration test beds. In addition, actuation has been predominantly based upon electromagnetic motors. Ironically, these elements are rarely found in the existing industrial long reach systems. This manuscript describes a new hydraulically actuated, long reach manipulator with a flexible prismatic link at Oak Ridge National Laboratory (ORNL). Focus is directed towards both modeling and control of hydraulic actuators as well as flexible links that have variable natural frequencies.

  19. Reducing model uncertainty effects in flexible manipulators through the addition of passive damping

    NASA Technical Reports Server (NTRS)

    Alberts, T. E.

    1987-01-01

    An important issue in the control of practical systems is the effect of model uncertainty on closed loop performance. This is of particular concern when flexible structures are to be controlled, due to the fact that states associated with higher frequency vibration modes are truncated in order to make the control problem tractable. Digital simulations of a single-link manipulator system are employed to demonstrate that passive damping added to the flexible member reduces adverse effects associated with model uncertainty. A controller was designed based on a model including only one flexible mode. This controller was applied to larger order systems to evaluate the effects of modal truncation. Simulations using a Linear Quadratic Regulator (LQR) design assuming full state feedback illustrate the effect of control spillover. Simulations of a system using output feedback illustrate the destabilizing effect of observation spillover. The simulations reveal that the system with passive damping is less susceptible to these effects than the untreated case.

  20. Robust cooperative control of two two-link flexible manipulators on the basis of quasi-static equations

    SciTech Connect

    Matsuno, Fumitoshi; Hatayama, Michinori

    1999-04-01

    In this paper, a dynamic model of a distributed parameter system and a control architecture are developed for the closed-chain motion of two two-link flexible manipulators holding a common rigid object in a horizontal workspace. The authors derive the dynamic relation of deformation of the flexible links, constraint force, and rigid-object dynamics. Use of the quasi-static relation of the deformation, the constraint force, and the rigid-object dynamics gives quasi-static equations of joint angles which are not dependent on the variables related to the deformations of the flexible links. The authors design a robust cooperative controller of the two flexible manipulators considering measurement disturbances and modeling errors caused by the link-parameter uncertainty and the quasi-static approximation. A set of experiments for the cooperative control of the two flexible manipulators using a force sensor has been carried out. Several experimental results are shown.

  1. Experimental verification of a model of a two-link flexible, lightweight manipulator. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Huggins, James David

    1988-01-01

    Experimental verification is presented for an assumed modes model of a large, two link, flexible manipulator design and constructed in the School of Mechanical Engineering at Georgia Institute of Technology. The structure was designed to have typical characteristics of a lightweight manipulator.

  2. Flexible optical manipulation of ring resonator by frequency detuning and double-port excitation.

    PubMed

    Geng, Yong; Zhu, Tongtong; Lv, Haiyi; Cao, Yongyin; Sun, Fangkui; Ding, Weiqiang

    2016-07-11

    Optical force exerted on a ring resonator, which can move freely in plane, is investigated using the finite-difference in time-domain method. In order to manipulate the ring resonator more flexibly, two assistant waveguides are introduced to form a microring resonator based add-drop device. Results show that a blue tuned source is more suitable for the manipulation of the ring, rather than the central resonant frequency as expected. A red-tuned frequency, however, is difficult to trap the ring stably. When the frequency detuning is combined with selected double-port excitation, the ring can be trapped stably at some discrete positions, some determined regions, or be transported continuously along the waveguide. This optically reconfigurable opto-mechanical resonant system may find potential applications in tunable photonic devices and precise sensing. PMID:27410856

  3. Effect of Lumbar Spine Manipulation on Asymptomatic Cyclist Sprint Performance and Hip Flexibility

    PubMed Central

    Olson, Eric; Bodziony, Michael; Ward, John; Coats, Jesse; Koby, Bradley; Goehry, Doug

    2014-01-01

    Objective The purpose of this study was to measure the impact of midlumbar spinal manipulation on asymptomatic cyclist sprint performance and hip flexibility. Methods Twelve cyclists were equally randomized into an AB:BA crossover study design after baseline testing. Six participants were in the AB group, and 6 were in the BA group. The study involved 1 week of rest in between each of the 3 tested conditions: baseline testing (no intervention prior to testing), condition A (bilateral midlumbar spine manipulation prior to testing), and condition B (sham acupuncture prior to testing, as a control). Testing was blinded and involved a sit-and-reach test followed by a 0.5-km cycle ergometer sprint test against 4-kp resistance. Outcome measures were sit-and-reach distance, time to complete 0.5 km, maximum heart rate, and rating of perceived exertion. An additional 8 cyclists were recruited and used as a second set of controls that engaged in 3 testing sessions without any intervention to track test acclimation. An analysis of variance was used to compare dependent variables under each of the 3 conditions for the experimental group and control group #1, and a repeated-measures analysis of variance was used to analyze test acclimation in control group #2. Results Lumbar spine manipulation did not demonstrate statistically significant between-group changes in sit-and-reach (P = .765), 0.5-km sprint performance time (P = .877), maximum exercise heart rate (P = .944), or rating of perceived exertion (P = .875). Conclusions The findings of this preliminary study showed that midlumbar spinal manipulation did not improve hip flexibility or cyclist power output of asymptomatic participants compared with an acupuncture sham and no-treatment control groups. PMID:25435836

  4. Application of model reference adaptive control to a flexible remote manipulator arm

    NASA Technical Reports Server (NTRS)

    Meldrum, D. R.; Balas, M. J.

    1986-01-01

    An exact modal state-space representation is derived in detail for a single-link, flexible remote manipulator with a noncollocated sensor and actuator. A direct model following adaptive controller is designed to control the torque at the pinned end of the arm so as to command the free end to track a prescribed sinusoidal motion. Conditions that must be satisfied in order for the controller to work are stated. Simulation results to date are discussed along with the potential of the model following adaptive control scheme in robotics and space environments.

  5. Experimental determination of frequency response function estimates for flexible joint industrial manipulators with serial kinematics

    NASA Astrophysics Data System (ADS)

    Saupe, Florian; Knoblach, Andreas

    2015-02-01

    Two different approaches for the determination of frequency response functions (FRFs) are used for the non-parametric closed loop identification of a flexible joint industrial manipulator with serial kinematics. The two applied experiment designs are based on low power multisine and high power chirp excitations. The main challenge is to eliminate disturbances of the FRF estimates caused by the numerous nonlinearities of the robot. For the experiment design based on chirp excitations, a simple iterative procedure is proposed which allows exploiting the good crest factor of chirp signals in a closed loop setup. An interesting synergy of the two approaches, beyond validation purposes, is pointed out.

  6. On controller tuning for a flexible-link manipulator with varying payload

    NASA Technical Reports Server (NTRS)

    Yurkovich, Stephen; Pachecho, Fernando E.

    1989-01-01

    In this article experimental results are presented for system identification and control of a single-link flexible manipulator carrying an unknown, varying payload. The control objective is to maintain endpoint position accuracy in the presence of flexure effects after rapid movement due to a rigid body slew-angle commanded position. Various time-domain parameter estimation techniques are used to identify ARMA model representations to be employed in controller tuning schemes for vibration compensation. Only endpoint acceleration measurements and motor shaft angle measurements are utilized in relatively simple PID control schemes, which are tuned as dictated by a varying, unknown payload.

  7. Active vibration control of Flexible Joint Manipulator using Input Shaping and Adaptive Parameter Auto Disturbance Rejection Controller

    NASA Astrophysics Data System (ADS)

    Li, W. P.; Luo, B.; Huang, H.

    2016-02-01

    This paper presents a vibration control strategy for a two-link Flexible Joint Manipulator (FJM) with a Hexapod Active Manipulator (HAM). A dynamic model of the multi-body, rigid-flexible system composed of an FJM, a HAM and a spacecraft was built. A hybrid controller was proposed by combining the Input Shaping (IS) technique with an Adaptive-Parameter Auto Disturbance Rejection Controller (APADRC). The controller was used to suppress the vibration caused by external disturbances and input motions. Parameters of the APADRC were adaptively adjusted to ensure the characteristic of the closed loop system to be a given reference system, even if the configuration of the manipulator significantly changes during motion. Because precise parameters of the flexible manipulator are not required in the IS system, the operation of the controller was sufficiently robust to accommodate uncertainties in system parameters. Simulations results verified the effectiveness of the HAM scheme and controller in the vibration suppression of FJM during operation.

  8. Direct adaptive fuzzy control of a translating piezoelectric flexible manipulator driven by a pneumatic rodless cylinder

    NASA Astrophysics Data System (ADS)

    Qiu, Zhi-cheng; Wang, Bin; Zhang, Xian-min; Han, Jian-da

    2013-04-01

    This study presents a novel translating piezoelectric flexible manipulator driven by a rodless cylinder. Simultaneous positioning control and vibration suppression of the flexible manipulator is accomplished by using a hybrid driving scheme composed of the pneumatic cylinder and a piezoelectric actuator. Pulse code modulation (PCM) method is utilized for the cylinder. First, the system dynamics model is derived, and its standard multiple input multiple output (MIMO) state-space representation is provided. Second, a composite proportional derivative (PD) control algorithms and a direct adaptive fuzzy control method are designed for the MIMO system. Also, a time delay compensation algorithm, bandstop and low-pass filters are utilized, under consideration of the control hysteresis and the caused high-frequency modal vibration due to the long stroke of the cylinder, gas compression and nonlinear factors of the pneumatic system. The convergence of the closed loop system is analyzed. Finally, experimental apparatus is constructed and experiments are conducted. The effectiveness of the designed controllers and the hybrid driving scheme is verified through simulation and experimental comparison studies. The numerical simulation and experimental results demonstrate that the proposed system scheme of employing the pneumatic drive and piezoelectric actuator can suppress the vibration and achieve the desired positioning location simultaneously. Furthermore, the adopted adaptive fuzzy control algorithms can significantly enhance the control performance.

  9. Photonic-assisted chirped microwave pulses generation with a flexible and fine parameter manipulation.

    PubMed

    Liu, Xinkai; Pan, Wei; Zou, Xihua; Yan, Lianshan; Luo, Bin; Zheng, Di; Ye, Jia; Lu, Bing

    2016-08-22

    A photonic approach for generating chirped microwave pulses with a flexible and fine parameter manipulation is proposed and experimentally demonstrated. In the proposed system, an intensity modulator (IM) biased at the minimum transmission point is used to generate two ± 1st-order optical sidebands which are then sent to a phase modulator (PM) for implementing large-signal phase modulations. A de-interleaver combined with an optical variable delay line (OVDL) is utilized to introduce a time delay between two phase-modulated optical signals. A second IM that acts as a time domain intensity switch (TDIS) is used to select different phase modulation ranges of the two phase-modulated optical signals. After the optical-electrical conversion in a photodetector (PD), chirped microwave pulses are generated. The key feature of this approach is that the parameters of the generated chirped microwave pulses including central frequency, pulse repetition frequency, and chirp rate can be flexibly and precisely manipulated by the radio frequency (RF) signals applied to modulators. A proof-of-principle experiment is carried out to verify the proposed approach. Consequently, positive or negative chirped microwave pulses with different central frequencies at 20, 22, 24 or 26 GHz and different pulse repetition frequencies at 1.5 or 2 GHz are generated, respectively. PMID:27557237

  10. A Scalable Long-Reach Wavelength-Division Multiplexing Access Network Sharing Both Fiber Protection and Broadcasting Services

    NASA Astrophysics Data System (ADS)

    Feng, Chen; Gan, Chaoqin; Gao, Ziyue; Guo, Su; Li, Wei; Fang, Yiqin

    2014-07-01

    A novel scalable wavelength-division multiplexing access network is proposed in this article. By newly designing the remote node, this network can not only support the long-reach transmission and broadcasting services, it can also have flexible scalability and the ability of sharing fiber protection. These make this network have great resilient capability. Also, this scheme still has the characteristic of Rayleigh backscattering mitigation and shared-seeding light of upstream signals. The simulation results indicate this network has good performance.

  11. Direct Adaptive Control Methodologies for Flexible-Joint Space Manipulators with Uncertainties and Modeling Errors

    NASA Astrophysics Data System (ADS)

    Ulrich, Steve

    This work addresses the direct adaptive trajectory tracking control problem associated with lightweight space robotic manipulators that exhibit elastic vibrations in their joints, and which are subject to parametric uncertainties and modeling errors. Unlike existing adaptive control methodologies, the proposed flexible-joint control techniques do not require identification of unknown parameters, or mathematical models of the system to be controlled. The direct adaptive controllers developed in this work are based on the model reference adaptive control approach, and manage modeling errors and parametric uncertainties by time-varying the controller gains using new adaptation mechanisms, thereby reducing the errors between an ideal model and the actual robot system. More specifically, new decentralized adaptation mechanisms derived from the simple adaptive control technique and fuzzy logic control theory are considered in this work. Numerical simulations compare the performance of the adaptive controllers with a nonadaptive and a conventional model-based controller, in the context of 12.6 m xx 12.6 m square trajectory tracking. To validate the robustness of the controllers to modeling errors, a new dynamics formulation that includes several nonlinear effects usually neglected in flexible-joint dynamics models is proposed. Results obtained with the adaptive methodologies demonstrate an increased robustness to both uncertainties in joint stiffness coefficients and dynamics modeling errors, as well as highly improved tracking performance compared with the nonadaptive and model-based strategies. Finally, this work considers the partial state feedback problem related to flexible-joint space robotic manipulators equipped only with sensors that provide noisy measurements of motor positions and velocities. An extended Kalman filter-based estimation strategy is developed to estimate all state variables in real-time. The state estimation filter is combined with an adaptive

  12. Modal analysis and control of flexible manipulator arms. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Neto, O. M.

    1974-01-01

    The possibility of modeling and controlling flexible manipulator arms was examined. A modal approach was used for obtaining the mathematical model and control techniques. The arm model was represented mathematically by a state space description defined in terms of joint angles and mode amplitudes obtained from truncation on the distributed systems, and included the motion of a two link two joint arm. Three basic techniques were used for controlling the system: pole allocation with gains obtained from the rigid system with interjoint feedbacks, Simon-Mitter algorithm for pole allocation, and sensitivity analysis with respect to parameter variations. An improvement in arm bandwidth was obtained. Optimization of some geometric parameters was undertaken to maximize bandwidth for various payload sizes and programmed tasks. The controlled system is examined under constant gains and using the nonlinear model for simulations following a time varying state trajectory.

  13. Nonlinear modeling of a long flexible manipulator and control by inertial devices

    NASA Technical Reports Server (NTRS)

    Barbieri, Enrique; Kenny, Sean P.; Montgomery, Raymond C.

    1992-01-01

    The authors consider the modeling and control of a planar, long flexible manipulator that is representative of current space-based robotic arms. The arm is equipped with three actuators: 1) a shoulder motor; 2) a torque wheel at the tip; and 3) a proof-mass actuator at the tip. The goal is to investigate the potential use of inertial devices as control inputs for maneuvering tasks and vibration suppression. The parameters used for the inertial devices at the tip are comparable to those specified for the Mini-Mast facility at the Langley Research Center. A nonlinear distributed parameter model is obtained by the extended Hamilton principle. The associated eigenvalue/eigenfunction problem is solved and a finite-dimensional state space model is assembled. A preliminary design of a linear quadratic regulator is used, and computer simulation results illustrate the benefits of using the proposed actuators.

  14. Active Vibration Control of a Large Flexible Manipulator by Inertial Force and Joint Torque. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Lee, Soo Han

    1988-01-01

    The efficiency and positional accuracy of a lightweight flexible manipulator are limited by its flexural vibrations, which last after a gross motion is completed. The vibration delays subsequent operations. In the proposed work, the vibration is suppressed by inertial force of a small arm in addition to the joint actuators and passive damping treatment. The proposed approach is: (1) Dynamic modeling of a combined system, a large flexible manipulator and a small arm, (2) Determination of optimal sensor location and controller algorithm, and (3) Verification of the fitness of model and the performance of controller.

  15. Flexible manipulation of microfluids using optically regulated adsorption/desorption of hydrophobic materials.

    PubMed

    Nagai, Hidenori; Irie, Takashi; Takahashi, Junko; Wakida, Shin-ichi

    2007-04-15

    To realize highly integrated micro total analysis systems (microTAS), a simply controlled miniaturized valve should be utilized on microfluidic device. In this paper, we describe the application of photo-induced super-hydrophilicity of titanium dioxide (TiO2) to microfluidic manipulation. In addition, we found a new phenomenon for reversibly converting the surface wettability using a polydimethylsiloxane (PDMS) matrix and the photocatalytic properties of TiO2. While PDMS polymer was irradiated with UV, it was confirmed that hydrophobic material was released from the polymer to air. Several prepolymers were identified as the hydrophobic material with a gas chromatograph and mass spectrometer (GC/MS). Here, we successfully demonstrated the flexible manipulation of microfluid in a branched microchannel using the reversible wettability as micro opto-switching valve (MOS/V). The simultaneous control of MOS/Vs was also demonstrated on a 256-MOS/V integrated disk. The MOS/V promises to be one of the most effective flow switching valves for advanced applications in highly integrated micro/nano fluidics. PMID:17027249

  16. Optimal target grasping of a flexible space manipulator for a class of objectives

    NASA Astrophysics Data System (ADS)

    Toglia, Chiara; Sabatini, Marco; Gasbarri, Paolo; Palmerini, Giovanni B.

    2011-04-01

    Space graspers are complex systems, composed by robotic arms placed on an orbiting platform. In order to fulfil the manoeuvres' requirements, it is necessary to properly model all the forces acting on the space robot. A fully nonlinear model is used to describe the dynamics, based on a multibody approach. The model includes the orbital motion, the gravity gradient, the aerodynamic effects, as well as the flexibility of the links. The present paper aims to design, thanks to nonlinear optimization algorithms, a class of manoeuvres that, given the same target to be grasped, are characterized by different mission objectives. The grasping mission can be performed with the objective to minimize the power consumption. Collision avoidance constraints can be also added when the target is equipped with solar panels or other appendices. In some cases, large elastic displacements should be expected, possibly leading to an inaccurate positioning of the end-effector. Therefore, different design strategies can require that the manoeuvre is accomplished with minimum vibrations' amplitude at the end-effector. Performance of the different strategies is analyzed in terms of control effort, trajectory errors, and flexible response of the manipulator.

  17. Light-driven 3D droplet manipulation on flexible optoelectrowetting devices fabricated by a simple spin-coating method.

    PubMed

    Jiang, Dongyue; Park, Sung-Yong

    2016-05-21

    Technical advances in electrowetting-on-dielectric (EWOD) over the past few years have extended our attraction to three-dimensional (3D) devices capable of providing more flexibility and functionality with larger volumetric capacity than conventional 2D planar ones. However, typical 3D EWOD devices require complex and expensive fabrication processes for patterning and wiring of pixelated electrodes that also restrict the minimum droplet size to be manipulated. Here, we present a flexible single-sided continuous optoelectrowetting (SCOEW) device which is not only fabricated by a spin-coating method without the need for patterning and wiring processes, but also enables light-driven 3D droplet manipulations. To provide photoconductive properties, previous optoelectrowetting (OEW) devices have used amorphous silicon (a-Si) typically fabricated through high-temperature processes over 300 °C such as CVD or PECVD. However, most of the commercially-available flexible substrates such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) experience serious thermal deformation under such high-temperature processes. Because of this compatibility issue of conventional OEW devices with flexible substrates, light-driven 3D droplet manipulations have not yet been demonstrated on flexible substrates. Our study overcomes this compatibility issue by using a polymer-based photoconductive material, titanium oxide phthalocyanine (TiOPc) and thus SCOEW devices can be simply fabricated on flexible substrates through a low-cost, spin-coating method. In this paper, analytical studies were conducted to understand the effects of light patterns on static contact angles and EWOD forces. For experimental validations of our study, flexible SCOEW devices were successfully fabricated through the TiOPc-based spin-coating method and light-driven droplet manipulations (e.g. transportation, merging, and splitting) have been demonstrated on various 3D terrains such as inclined

  18. Vibration control of a pneumatic driven piezoelectric flexible manipulator using self-organizing map based multiple models

    NASA Astrophysics Data System (ADS)

    Zhao, Zhi-li; Qiu, Zhi-cheng; Zhang, Xian-min; Han, Jian-da

    2016-03-01

    A kind of hybrid pneumatic-piezoelectric flexible manipulator system has been presented in the paper. A hybrid driving scheme is achieved by combining of a pneumatic proportional valve based pneumatic drive and a piezoelectric actuator bonded to the flexible beam. The system dynamics models are obtained based on system identification approaches, using the established experimental system. For system identification of the flexible piezoelectric manipulator subsystem, parametric estimation methods are utilized. For the pneumatic driven system, a single global linear model is not accurate enough to describe its dynamics, due to the high nonlinearity of the pneumatic driven system. Therefore, a self-organizing map (SOM) based multi-model system identification approach is used to get multiple local linear models. Then, a SOM based multi-model inverse controller and a variable damping pole-placement controller are applied to the pneumatic drive and piezoelectric actuator, respectively. Experiments on pneumatic driven vibration control, piezoelectric vibration control and hybrid vibration control are conducted, utilized proportional and derivative (PD) control, SOM based multi-model inverse controller, and the variable damping pole-placement controller. Experimental results demonstrate that the investigated control algorithms can improve the vibration control performance of the pneumatic driven flexible piezoelectric manipulator system.

  19. On utilizing alternating current-flow field effect transistor for flexibly manipulating particles in microfluidics and nanofluidics.

    PubMed

    Liu, Weiyu; Shao, Jinyou; Ren, Yukun; Liu, Jiangwei; Tao, Ye; Jiang, Hongyuan; Ding, Yucheng

    2016-05-01

    By imposing a biased gate voltage to a center metal strip, arbitrary symmetry breaking in induced-charge electroosmotic flow occurs on the surface of this planar gate electrode, a phenomenon termed as AC-flow field effect transistor (AC-FFET). In this work, the potential of AC-FFET with a shiftable flow stagnation line to flexibly manipulate micro-nano particle samples in both a static and continuous flow condition is demonstrated via theoretical analysis and experimental validation. The effect of finite Debye length of induced double-layer and applied field frequency on the manipulating flexibility factor for static condition is investigated, which indicates AC-FFET turns out to be more effective for achieving a position-controllable concentrating of target nanoparticle samples in nanofluidics compared to the previous trial in microfluidics. Besides, a continuous microfluidics-based particle concentrator/director is developed to deal with incoming analytes in dynamic condition, which exploits a design of tandem electrode configuration to consecutively flow focus and divert incoming particle samples to a desired downstream branch channel, as prerequisite for a following biochemical analysis. Our physical demonstrations with AC-FFET prove valuable for innovative designs of flexible electrokinetic frameworks, which can be conveniently integrated with other microfluidic or nanofluidic components into a complete lab-on-chip diagnostic platform due to a simple electrode structure. PMID:27190570

  20. Exact and explicit optimal solutions for trajectory planning and control of single-link flexible-joint manipulators

    NASA Technical Reports Server (NTRS)

    Chen, Guanrong

    1991-01-01

    An optimal trajectory planning problem for a single-link, flexible joint manipulator is studied. A global feedback-linearization is first applied to formulate the nonlinear inequality-constrained optimization problem in a suitable way. Then, an exact and explicit structural formula for the optimal solution of the problem is derived and the solution is shown to be unique. It turns out that the optimal trajectory planning and control can be done off-line, so that the proposed method is applicable to both theoretical analysis and real time tele-robotics control engineering.

  1. A vision-based end-point control for a two-link flexible manipulator. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Obergfell, Klaus

    1991-01-01

    The measurement and control of the end-effector position of a large two-link flexible manipulator are investigated. The system implementation is described and an initial algorithm for static end-point positioning is discussed. Most existing robots are controlled through independent joint controllers, while the end-effector position is estimated from the joint positions using a kinematic relation. End-point position feedback can be used to compensate for uncertainty and structural deflections. Such feedback is especially important for flexible robots. Computer vision is utilized to obtain end-point position measurements. A look-and-move control structure alleviates the disadvantages of the slow and variable computer vision sampling frequency. This control structure consists of an inner joint-based loop and an outer vision-based loop. A static positioning algorithm was implemented and experimentally verified. This algorithm utilizes the manipulator Jacobian to transform a tip position error to a joint error. The joint error is then used to give a new reference input to the joint controller. The convergence of the algorithm is demonstrated experimentally under payload variation. A Landmark Tracking System (Dickerson, et al 1990) is used for vision-based end-point measurements. This system was modified and tested. A real-time control system was implemented on a PC and interfaced with the vision system and the robot.

  2. Optimal trajectories for flexible-link manipulator slewing using recursive quadratic programming: Experimental verification

    SciTech Connect

    Parker, G.G.; Eisler, G.R.; Feddema, J.T.

    1994-09-01

    Procedures for trajectory planning and control of flexible link robots are becoming increasingly important to satisfy performance requirements of hazardous waste removal efforts. It has been shown that utilizing link flexibility in designing open loop joint commands can result in improved performance as opposed to damping vibration throughout a trajectory. The efficient use of link compliance is exploited in this work. Specifically, experimental verification of minimum time, straight line tracking using a two-link planar flexible robot is presented. A numerical optimization process, using an experimentally verified modal model, is used for obtaining minimum time joint torque and angle histories. The optimal joint states are used as commands to the proportional-derivative servo actuated joints. These commands are precompensated for the nonnegligible joint servo actuator dynamics. Using the precompensated joint commands, the optimal joint angles are tracked with such fidelity that the tip tracking error is less than 2.5 cm.

  3. Flexibility.

    ERIC Educational Resources Information Center

    Humphrey, L. Dennis

    1981-01-01

    Flexibility is an important aspect of all sports and recreational activities. Flexibility can be developed and maintained by stretching exercises. Exercises designed to develop flexibility in ankle joints, knees, hips, and the lower back are presented. (JN)

  4. Manipulating flexible parts using a teleoperated system with time delay: An experiment

    NASA Technical Reports Server (NTRS)

    Kotoku, T.; Takamune, K.; Tanie, K.; Komoriya, K.; Matsuhira, N.; Asakura, M.; Bamba, H.

    1994-01-01

    This paper reports experiments involving the handling of flexible parts (e.g. wires) when using a teleoperated system with time delay. The task is principally a peg-in-hole task involving the wrapping of a wire around two posts on the task-board. It is difficult to estimate the effects of the flexible parts; therefore, on-line teleoperation is indispensable for this class of unpredictable task. We first propose a teleoperation system based on the predictive image display, then describe an experimental teleoperation testbed with a four second transmission time delay. Finally, we report on wire handling operations that were performed to evaluate the performance of this system. Those experiments will contribute to future advanced experiments for the MITI ETS-7 mission.

  5. Dynamic control modification techniques in teleoperation of a flexible manipulator. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Magee, David Patrick

    1991-01-01

    The objective of this research is to reduce the end-point vibration of a large, teleoperated manipulator while preserving the usefulness of the system motion. A master arm is designed to measure desired joint angles as the user specifies a desired tip motion. The desired joint angles from the master arm are the inputs to an adaptive PD control algorithm that positions the end-point of the manipulator. As the user moves the tip of the master, the robot will vibrate at its natural frequencies which makes it difficult to position the end-point. To eliminate the tip vibration during teleoperated motions, an input shaping method is presented. The input shaping method transforms each sample of the desired input into a new set of impulses that do not excite the system resonances. The method is explained using the equation of motion for a simple, second-order system. The impulse response of such a system is derived and the constraint equations for vibrationless motion are presented. To evaluate the robustness of the method, a different residual vibration equation from Singer's is derived that more accurately represents the input shaping technique. The input shaping method is shown to actually increase the residual vibration in certain situations when the system parameters are not accurately specified. Finally, the implementation of the input shaping method to a system with varying parameters is shown to induce a vibration into the system. To eliminate this vibration, a modified command shaping technique is developed. The ability of the modified command shaping method to reduce vibration at the system resonances is tested by varying input perturbations to trajectories in a range of possible user inputs. By comparing the frequency responses of the transverse acceleration at the end-point of the manipulator, the modified method is compared to the original PD routine. The control scheme that produces the smaller magnitude of resonant vibration at the first natural frequency is

  6. Convergent optical wired and wireless long-reach access network using high spectral-efficient modulation.

    PubMed

    Chow, C W; Lin, Y H

    2012-04-01

    To provide broadband services in a single and low cost perform, the convergent optical wired and wireless access network is promising. Here, we propose and demonstrate a convergent optical wired and wireless long-reach access networks based on orthogonal wavelength division multiplexing (WDM). Both the baseband signal and the radio-over-fiber (ROF) signal are multiplexed and de-multiplexed in optical domain, hence it is simple and the operation speed is not limited by the electronic bottleneck caused by the digital signal processing (DSP). Error-free de-multiplexing and down-conversion can be achieved for all the signals after 60 km (long-reach) fiber transmission. The scalability of the system for higher bit-rate (60 GHz) is also simulated and discussed. PMID:22513636

  7. Control of flexible robots with prismatic joints and hydraulic drives

    SciTech Connect

    Love, L.J.; Kress, R.L.; Jansen, J.F.

    1997-03-01

    The design and control of long-reach, flexible manipulators has been an active research topic for over 20 years. Most of the research to date has focused on single link, fixed length, single plane of vibration test beds. In addition, actuation has been predominantly based upon electromagnetic motors. Ironically, these elements are rarely found in the existing industrial long-reach systems. One example is the Modified Light Duty Utility Arm (MLDUA) designed and built by Spar Aerospace for Oak Ridge National Laboratory (ORNL). This arm operates in larger, underground waste storage tanks located at ORNL. The size and nature of the tanks require that the robot have a reach of approximately 15 ft and a payload capacity of 250 lb. In order to achieve these criteria, each joint is hydraulically actuated. Furthermore, the robot has a prismatic degree-of-freedom to ease deployment. When fully extended, the robot`s first natural frequency is 1.76 Hz. Many of the projected tasks, coupled with the robot`s flexibility, present an interesting problem. How will many of the existing flexure control algorithms perform on a hydraulic, long-reach manipulator with prismatic links? To minimize cost and risk of testing these algorithms on the MLDUA, the authors have designed a new test bed that contains many of the same elements. This manuscript described a new hydraulically actuated, long-reach manipulator with a flexible prismatic link at ORNL. Focus is directed toward both modeling and control of hydraulic actuators as well as flexible links that have variable natural frequencies.

  8. Passivity/Lyapunov based controller design for trajectory tracking of flexible joint manipulators

    NASA Technical Reports Server (NTRS)

    Sicard, Pierre; Wen, John T.; Lanari, Leonardo

    1992-01-01

    A passivity and Lyapunov based approach for the control design for the trajectory tracking problem of flexible joint robots is presented. The basic structure of the proposed controller is the sum of a model-based feedforward and a model-independent feedback. Feedforward selection and solution is analyzed for a general model for flexible joints, and for more specific and practical model structures. Passivity theory is used to design a motor state-based controller in order to input-output stabilize the error system formed by the feedforward. Observability conditions for asymptotic stability are stated and verified. In order to accommodate for modeling uncertainties and to allow for the implementation of a simplified feedforward compensation, the stability of the system is analyzed in presence of approximations in the feedforward by using a Lyapunov based robustness analysis. It is shown that under certain conditions, e.g., the desired trajectory is varying slowly enough, stability is maintained for various approximations of a canonical feedforward.

  9. Minimum-time trajectory control of a two-link flexible robotic manipulator

    SciTech Connect

    Schoenwald, D.A.; Feddema, J.T.; Eisler, G.R.; Segalman, D.J.

    1990-01-01

    This paper analyzes the experimental and simulation results of a minimum-time trajectory control scheme for a two-link flexible robot. An off-line optimization routine determines a minimum-time, straight line tip trajectory which stays within the torque constraints of the motors and ends in a quiescent state, i.e., no vibrational transients. An efficient finite-element model is used in the optimization to approximate the flexible arm dynamics. The control strategy described here is used to determine the feedback gains for the position, velocity, and strain gage signals from a quadratic cost criterion based on the finite-element model linearized about the straight line tip trajectory. These feedback signals are added to the modeled torque obtained from the optimization routine and used to control the robot arm actuators. The results indicate that this combination of model-based and error-driven control strategies achieves a closer tracking of the desired trajectory and a better handling of modeling errors (such as tip payloads) than either strategy alone.

  10. Advances in dynamics and control of flexible spacecraft and space-based manipulations; Proceedings of the Symposium, ASME Winter Annual Meeting, Dallas, TX, Nov. 25-30, 1990

    NASA Astrophysics Data System (ADS)

    Joshi, Suresh M.; Alberts, Thomas E.; Kakad, Yogendra P.

    Consideration is given to control formulations for vibration suppression of an active structure in slewing motions, the use if distributed sensing in control of large flexible spacecraft, an improved shooting method for solving minimum-time maneuver problems, and nonlinear slew maneuver dynamics of large flexible spacecrafts. Attention is also given to initial experiments in trusterless locomotion control of a free-flying robot, dynamic analysis to evaluate viscoelastic passive damping augmentation for the Space Shuttle Remote Manipulator System, initial experiments in cooperative manipulation from a moving platform, and intelligent pipelined control architecture for remote robotic applications.

  11. Advances in dynamics and control of flexible spacecraft and space-based manipulations; Proceedings of the Symposium, ASME Winter Annual Meeting, Dallas, TX, Nov. 25-30, 1990

    NASA Technical Reports Server (NTRS)

    Joshi, Suresh M. (Editor); Alberts, Thomas E. (Editor); Kakad, Yogendra P. (Editor)

    1990-01-01

    Consideration is given to control formulations for vibration suppression of an active structure in slewing motions, the use if distributed sensing in control of large flexible spacecraft, an improved shooting method for solving minimum-time maneuver problems, and nonlinear slew maneuver dynamics of large flexible spacecrafts. Attention is also given to initial experiments in trusterless locomotion control of a free-flying robot, dynamic analysis to evaluate viscoelastic passive damping augmentation for the Space Shuttle Remote Manipulator System, initial experiments in cooperative manipulation from a moving platform, and intelligent pipelined control architecture for remote robotic applications.

  12. Certification of a hybrid parameter model of the fully flexible Shuttle Remote Manipulator System

    NASA Technical Reports Server (NTRS)

    Barhorst, Alan A.

    1995-01-01

    The development of high fidelity models of mechanical systems with flexible components is in flux. Many working models of these devices assume the elastic motion is small and can be superimposed on the overall rigid body motion. A drawback associated with this type of modeling technique is that it is required to regenerate the linear modal model of the device if the elastic motion is sufficiently far from the base rigid motion. An advantage to this type of modeling is that it uses NASTRAN modal data which is the NASA standard means of modal information exchange. A disadvantage to the linear modeling is that it fails to accurately represent large motion of the system, unless constant modal updates are performed. In this study, which is a continuation of a project started last year, the drawback of the currently used modal snapshot modeling technique is addressed in a rigorous fashion by novel and easily applied means.

  13. Control of a small working robot on a large flexible manipulator for suppressing vibrations

    NASA Technical Reports Server (NTRS)

    Lee, Soo Han

    1991-01-01

    The short term objective of this research is the completion of experimental configuration of the Small Articulated Robot (SAM) and the derivations of the actuator dynamics of the Robotic Arm, Large and Flexible (RALF). In order to control vibrations SAM should have larger bandwidth than that of the vibrations. The bandwidth of SAM consist of 3 parts; structural rigidity, processing speed of controller, and motor speed. The structural rigidity was increased to a reasonably high value by attaching aluminum angles at weak points and replacing thin side plates by thicker ones. The high processing speed of the controller was achieved by using parallel processors (three 68000 process, three interface board, and one main processor (IBM-XT)). Maximum joint speed and acceleration of SAM is known as about 4 rad/s and 15 rad/sq s. Hence SAM can move only .04 rad at 3 Hz which is the natural frequency of RALF. This will be checked by experiment.

  14. ONU discovery using multiple subchannels for seamless service support in long-reach OFDMA-PON.

    PubMed

    Bang, Hakjeon; Doo, Kyeong-Hwan; Lee, Jonghyun; Lee, Sangsoo

    2014-09-01

    In a passive optical network (PON), discovery is a process that detects and registers newly connected optical network units (ONUs). A long-reach PON requires a longer discovery window, e.g., at least 1 ms for 100 km, due to the increased round-trip time between an optical line terminal (OLT) and an ONU. The longer discovery window consumes more network resources and issues longer service-interruption time. From this motivation, for a long-reach orthogonal frequency-division multiple access (OFDMA)-PON, we propose a discovery method using multiple subchannels, where each subchannel consists of one or several subcarrier(s). Compared to discovery using a single channel, the proposed discovery method can increase the number of successfully detected ONUs at the same resources (i.e., for a discovery window) and ensure seamless service support to already registered ONUs, by assigning some subchannels for discovery and the remainder for data transmission. We analyze the discovery efficiency (i.e., the number of successfully detected ONUs in the discovery process) based on a probability and optimize the discovery window size by numerical simulations. PMID:25321588

  15. A long-reach WDM passive optical network enabling broadcasting service with centralized light source

    NASA Astrophysics Data System (ADS)

    Liu, D.; Tang, M.; Fu, S.; Liu, D.; Shum, P.

    2012-02-01

    We propose a long-reach wavelength-division-multiplexed (WDM) passive optical network (PON) to provide conventional point-to-point (P2P) data and downstream broadcasting service simultaneously by superimposing, for each WDM channel, the differential-phase-shift-keying (DPSK) broadcasting signal with the subcarrier multiplexing (SCM) modulated downstream P2P signal, at the optical line terminal (OLT). In the optical network units (ONUs), by re-modulating part of the downstream signal with a reflective semiconductor optical amplifier (RSOA), we realize color-less ONUs for upstream data transmission. The proposed scheme is numerically verified with a 5 Gb/s downstream P2P signal and broadcasting services, as well as 2.5 Gb/s upstream data through a 60 km bidirectional fiber link. In particular, the influence of the downstream lightwave's optical carrier-subcarrier ratio (OCSR) on the system performance is also investigated.

  16. Protection of long-reach PON traffic through router database synchronization

    NASA Astrophysics Data System (ADS)

    Hunter, David K.; Lu, Zheng; Gilfedder, Tim H.

    2007-05-01

    A resilience strategy is introduced for networks implementing dual homing (dual parenting) of customers, specifically those employing long-reach PONs (LR-PONs). Assuming that some mechanism exists to detect network element failures, the discussion concentrates on protocols that propagate information about customer reachability and how this information reroutes traffic in the event of a fault. Each router holds a database indicating which other routers, and which LR-PONs, are available within the network, and these are synchronized between routers using IP. This information is used to reroute traffic in the event of failure. Simulation and analysis show that signaling time lies well within 50ms, leaving sufficient time for redirection of user traffic.

  17. Direct-detection optical OFDM superchannel for long-reach PON using pilot regeneration.

    PubMed

    Hu, Rong; Yang, Qi; Xiao, Xiao; Gui, Tao; Li, Zhaohui; Luo, Ming; Yu, Shaohua; You, Shanhong

    2013-11-01

    We demonstrate a novel long-reach PON downstream scheme based on the regenerated pilot assisted direct-detection optical orthogonal frequency division multiplexing (DDO-OFDM) superchannel transmission. We use the optical comb source to form DDO-OFDM superchannel, and reserve the center carrier as a seed pilot. The seed pilot is further tracked and reused to generate multiple optical carriers at the local exchange. Each regenerated pilot carrier is selected to beat with an adjacent OFDM sub-band at ONU, so that the electrical bandwidth limitation can be much released compared to the conventional DDO-OFDM superchannel detection. With the proposed proof-of-concept architecture, we experimentally demonstrated a 116.7 Gb/s superchannel OFDM-PON system with transmission reach of 100 km, and 1:64 splitting ratio. We analyze the impact of carrier-to-sideband power ratio (CSPR) on system performance. The experiment result shows that, 5 dB power margin is still remained at ONU using such technique. PMID:24216872

  18. A high performance long-reach passive optical network with a novel excess bandwidth distribution scheme

    NASA Astrophysics Data System (ADS)

    Chao, I.-Fen; Zhang, Tsung-Min

    2015-06-01

    Long-reach passive optical networks (LR-PONs) have been considered to be promising solutions for future access networks. In this paper, we propose a distributed medium access control (MAC) scheme over an advantageous LR-PON network architecture that reroutes the control information from and back to all ONUs through an (N + 1) × (N + 1) star coupler (SC) deployed near the ONUs, thereby overwhelming the extremely long propagation delay problem in LR-PONs. In the network, the control slot is designed to contain all bandwidth requirements of all ONUs and is in-band time-division-multiplexed with a number of data slots within a cycle. In the proposed MAC scheme, a novel profit-weight-based dynamic bandwidth allocation (P-DBA) scheme is presented. The algorithm is designed to efficiently and fairly distribute the amount of excess bandwidth based on a profit value derived from the excess bandwidth usage of each ONU, which resolves the problems of previously reported DBA schemes that are either unfair or inefficient. The simulation results show that the proposed decentralized algorithms exhibit a nearly three-order-of-magnitude improvement in delay performance compared to the centralized algorithms over LR-PONs. Moreover, the newly proposed P-DBA scheme guarantees low delay performance and fairness even when under attack by the malevolent ONU irrespective of traffic loads and burstiness.

  19. OTACT: ONU Turning with Adaptive Cycle Times in Long-Reach PONs

    NASA Astrophysics Data System (ADS)

    Zare, Sajjad; Ghaffarpour Rahbar, Akbar

    2015-01-01

    With the expansion of PON networks as Long-Reach PON (LR-PON) networks, the problem of degrading the efficiency of centralized bandwidth allocation algorithms threatens this network due to high propagation delay. This is because these algorithms are based on bandwidth negotiation messages frequently exchanged between the optical line terminal (OLT) in the Central Office and optical network units (ONUs) near the users, which become seriously delayed when the network is extended. To solve this problem, some decentralized algorithms are proposed based on bandwidth negotiation messages frequently exchanged between the Remote Node (RN)/Local Exchange (LX) and ONUs near the users. The network has a relatively high delay since there are relatively large distances between RN/LX and ONUs, and therefore, control messages should travel twice between ONUs and RN/LX in order to go from one ONU to another ONU. In this paper, we propose a novel framework, called ONU Turning with Adaptive Cycle Times (OTACT), that uses Power Line Communication (PLC) to connect two adjacent ONUs. Since there is a large population density in urban areas, ONUs are closer to each other. Thus, the efficiency of the proposed method is high. We investigate the performance of the proposed scheme in contrast with other decentralized schemes under the worst case conditions. Simulation results show that the average upstream packet delay can be decreased under the proposed scheme.

  20. Manipulation strategies for massive space payloads

    NASA Technical Reports Server (NTRS)

    Book, Wayne J.

    1991-01-01

    Motion planning and control for the joints of flexible manipulators are discussed. Specific topics covered include control of a flexible braced manipulator, control of a small working robot on a large flexible manipulator to suppress vibrations, control strategies for ensuring cooperation among disparate manipulators, and motion planning for robots in free-fall.

  1. Distributed piezoelectric vibration control for a flexible-link manipulator based on an observer in the form of partial differential equations

    NASA Astrophysics Data System (ADS)

    Yang, Hongjun; Liu, Jinkun

    2016-02-01

    This paper mainly focuses on designing a distributed observer-based controller for a flexible-link manipulator bonded with piezoelectric actuators. The dynamic model of the link can be taken as an Euler-Bernoulli beam and takes on the form of partial differential equations (PDEs). The proposed observer, which is proven exponentially stable, has the ability to estimate infinite dimensional states, and only the boundary practical measurement values are needed. A novel distributed observer-based controller is subsequently developed to make the joint position track a desired trajectory and rapidly regulate vibrations on the whole beam, which is the main contribution of the paper. The closed-loop system is guaranteed exponentially stable by theoretical analysis and its favorable performance is demonstrated by numerical simulations.

  2. Out-reach in-space technology experiments program: Control of flexible robot manipulators in zero gravity, experiment definition phase

    NASA Technical Reports Server (NTRS)

    Phillips, Warren F.

    1989-01-01

    The results obtained show that it is possible to control light-weight robots with flexible links in a manner that produces good response time and does not induce unacceptable link vibrations. However, deflections induced by gravity cause large static position errors with such a control system. For this reason, it is not possible to use this control system for controlling motion in the direction of gravity. The control system does, on the other hand, have potential for use in space. However, in-space experiments will be needed to verify its applicability to robots moving in three dimensions.

  3. Electric pulses: a flexible tool to manipulate cytosolic calcium concentrations and generate spontaneous-like calcium oscillations in mesenchymal stem cells

    PubMed Central

    de Menorval, Marie-Amelie; Andre, Franck M.; Silve, Aude; Dalmay, Claire; Français, Olivier; Le Pioufle, Bruno; Mir, Lluis M.

    2016-01-01

    Human adipose mesenchymal stem cells (haMSCs) are multipotent adult stem cells of great interest in regenerative medicine or oncology. They present spontaneous calcium oscillations related to cell cycle progression or differentiation but the correlation between these events is still unclear. Indeed, it is difficult to mimic haMSCs spontaneous calcium oscillations with chemical means. Pulsed electric fields (PEFs) can permeabilise plasma and/or organelles membranes depending on the applied pulses and therefore generate cytosolic calcium peaks by recruiting calcium from the external medium or from internal stores. We show that it is possible to mimic haMSCs spontaneous calcium oscillations (same amplitude, duration and shape) using 100 μs PEFs or 10 ns PEFs. We propose a model that explains the experimental situations reported. PEFs can therefore be a flexible tool to manipulate cytosolic calcium concentrations. This tool, that can be switched on and off instantaneously, contrary to chemicals agents, can be very useful to investigate the role of calcium oscillations in cell physiology and/or to manipulate cell fate. PMID:27561994

  4. Hybrid PD and effective multi-mode positive position feedback control for slewing and vibration suppression of a smart flexible manipulator

    NASA Astrophysics Data System (ADS)

    Lou, Jun-qiang; Wei, Yan-ding; Yang, Yi-ling; Xie, Feng-ran

    2015-03-01

    A hybrid control strategy for slewing and vibration suppression of a smart flexible manipulator is presented in this paper. It consists of a proportional derivative controller to realize motion control, and an effective multi-mode positive position feedback (EMPPF) controller to suppress the multi-mode vibration. Rather than treat each mode equally as the standard multi-mode PPF, the essence of the EMPPF is that control forces of different modes are applied according to the mode parameters of the respective modes, so the vibration modes with less vibration energy receive fewer control forces. Stability conditions for the close loop system are established through stability analysis. Optimal parameters of the EMPPF controller are obtained using the method of root locus analysis. The performance of the proposed strategy is demonstrated by simulation and experiments. Experimental results show that the first two vibration modes of the manipulator are effectively suppressed. The setting time of the setup descends approximately 55%, reaching 3.12 s from 5.67 s.

  5. Long reach DWDM-PON with 12.5 GHz channel spacing based on comb source seeding

    NASA Astrophysics Data System (ADS)

    Zhou, Zhao; Nie, Hai-tao; Wang, Yao-jun

    2016-07-01

    A long reach dense wavelength division multiplexing passive optical network (DWDM-PON) with 12.5 GHz channel spacing is proposed and experimentally demonstrated. An optical frequency comb source is used to provide the multiwavelength seeding light, while reflective semiconductor optical amplifiers (RSOAs) are installed in both optical line terminal (OLT) and optical network units (ONUs) as colorless transmitter. The experimental results show that the bidirectional transmission for 1.2 Gbit/s data rate is achieved over 80 km single mode fiber (SMF).

  6. 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.

  7. High-capacity and low-cost long-reach OFDMA PON based on distance-adaptive bandwidth allocation.

    PubMed

    Hu, Xiaofeng; Cao, Pan; Wu, Jiayang; Mao, Junming; Lv, Jianxin; Jiang, Yuling; Qiu, Ciyuan; Tremblay, Christine; Su, Yikai

    2015-01-26

    We propose and experimentally demonstrate a distance-adaptive bandwidth allocation scheme to realize high-capacity long-reach orthogonal frequency division multiple access passive optical network (OFDMA PON) with cost-effective electro-absorption modulator (EAM). In our scheme, the subcarriers in downstream OFDM signal are properly allocated to the optical network units (ONUs) with different fiber transmission lengths. By this means, the detrimental influence of power fading induced by dispersion and chirp can be avoided, thus all OFDM subcarriers can be modulated with high-order quadrature amplitude modulation (QAM) format, leading to a high transmission capacity. A proof-of-concept experiment is performed, in which three ONUs with transmission distances of 25, 50, and 100 km are assigned with different subcarriers, respectively. By using distance-adaptive bandwidth allocation technique, an OFDM signal of 34.5 Gb/s is successfully delivered to the ONUs with a bit error ratio (BER) lower than 2 × 10(-3). PMID:25835883

  8. All-optical virtual private network system in OFDM based long-reach PON using RSOA re-modulation technique

    NASA Astrophysics Data System (ADS)

    Kim, Chang-Hun; Jung, Sang-Min; Kang, Su-Min; Han, Sang-Kook

    2015-01-01

    We propose an all-optical virtual private network (VPN) system in an orthogonal frequency division multiplexing (OFDM) based long reach PON (LR-PON). In the optical access network field, technologies based on fundamental upstream (U/S) and downstream (D/S) have been actively researched to accommodate explosion of data capacity. However, data transmission among the end users which is arisen from cloud computing, file-sharing and interactive game takes a large weight inside of internet traffic. Moreover, this traffic is predicted to increase more if Internet of Things (IoT) services are activated. In a conventional PON, VPN data is transmitted through ONU-OLT-ONU via U/S and D/S carriers. It leads to waste of bandwidth and energy due to O-E-O conversion in the OLT and round-trip propagation between OLT and remote node (RN). Also, it causes inevitable load to the OLT for electrical buffer, scheduling and routing. The network inefficiency becomes more critical in a LR-PON which has been researched as an effort to reduce CAPEX and OPEX through metro-access consolidation. In the proposed system, the VPN data is separated from conventional U/S and re-modulated on the D/S carrier by using RSOA in the ONUs to avoid bandwidth consumption of U/S and D/S unlike in previously reported system. Moreover, the transmitted VPN data is re-directed to the ONUs by wavelength selective reflector device in the RN without passing through the OLT. Experimental demonstration for the VPN communication system in an OFDM based LR-PON has been verified.

  9. Simulation of robot manipulators

    SciTech Connect

    Kress, R.L.; Babcock, S.M.; Bills, K.C.; Kwon, D.S.; Schoenwald, D.A.

    1995-03-01

    This paper describes Oak Ridge National Laboratory`s development of an environment for the simulation of robotic manipulators. Simulation includes the modeling of kinematics, dynamics, sensors, actuators, control systems, operators, and environments. Models will be used for manipulator design, proposal evaluation, control system design and analysis, graphical preview of proposed motions, safety system development, and training. Of particular interest is the development of models for robotic manipulators having at least one flexible link. As a first application, models have been developed for the Pacific Northwest Laboratories` Flexible Beam Testbed which is a one-Degree-Of-Freedom, flexible arm with a hydraulic base actuator. Initial results show good agreement between model and experiment.

  10. 60 GHz millimeter-wave gigabit wireless services over long-reach passive optical network using remote signal regeneration and upconversion.

    PubMed

    Chien, Hung-Chang; Chowdhury, Arshad; Jia, Zhensheng; Hsueh, Yu-Ting; Chang, Gee-Kung

    2009-03-01

    This study proposed and experimentally demonstrated a cost-efficient scheme that can deliver 60 GHz millimeter-wave (mm-wave) multi-gigabit wireless services over 125 km long-reach passive optical networks (PONs) without any dispersion compensation. By introducing a remote local exchange (LE) stage with robust signal regeneration and all-optical upconversion functionalities, the proposed long-reach optical-wireless access network can easily accommodate over 128 users with 2.5 Gb/s shared bandwidth as well as shifting the capital expenditure of multiple hybrid optical network units (ONUs) toward single LE headend. Experimental verification shows that the power penalties for wireless and wired services are 1.8 dB and 0.4 dB at 10(-9) BER after 125 km optical fiber transmission. PMID:19259138

  11. Channel-reuse bidirectional transmission at 10 Gb/s/λ in long-reach DWDM-PON employing self wavelength managed tunable laser

    NASA Astrophysics Data System (ADS)

    Zhang, Zhiguo; Wang, Jiahe; Jiang, Xu; Chen, Xue; Wang, Liqian

    2015-05-01

    We experimentally demonstrate a channel-reuse, bidirectional, 10 Gb/s/λ, long-reach dense wavelength-division-multiplexing passive optical network (DWDM-PON) and an optical beat noise-based automatic wavelength control method for a tunable laser used in a colorless optical network unit (ONU). A 42 km reach, channel-reuse, full-duplex, 10 Gb/s transmission on a 50 GHz DWDM grid is achieved. Transmission performance is also measured with different optical-signal-to-Rayleigh-backscattering-noise ratios (OSRBNRs) and different central wavelength shifts (WSs) between upstream signal and downstream signal in the channel-reuse system.

  12. Long-reach transmission experiment of a wavelength division multiplexed-passive optical networks transmitter based on reflective semiconductor optical amplifiers

    NASA Astrophysics Data System (ADS)

    Jeon, Sie-Wook; Kim, Youngbok; Park, Chang-Soo

    2012-01-01

    We propose and demonstrate a long-reach wavelength division multiplexed-passive optical networks (WDM-PON) based on reflective semiconductor optical amplifiers (RSOAs) with easy maintenance of the optical source. Unlike previous studies the proposed WDM-PON uses two RSOAs: one for wavelength-selected light generation to provide a constant seed light to the second RSOA, the other for active external modulation. This method is free from intensity-fluctuated power penalties inherent to directly modulated single-RSOA sources, making long-reach transmission possible. Also, the wavelength of the modulated signal can easily be changed for the same RSOA by replacing the external feedback reflector, such as a fiber Bragg grating, or via thermal tuning. The seed light has a high-side-mode suppression ratio (SMSR) of 45 dB, and the bit error rate (BER) curve reveals that the upstream 1.25-Gb/s nonreturn-to-zero (NRZ) signal with a pseudo-random binary sequence (PRBS) of length of 215-1 has power penalties of 0.22 and 0.69 dB at BERs of 10-9 after 55-km and 110-km transmission due to fiber dispersion, respectively.

  13. Adaptive upstream rate adjustment by RSOA-ONU depending on different injection power of seeding light in standard-reach and long-reach PON systems

    NASA Astrophysics Data System (ADS)

    Yeh, C. H.; Chow, C. W.; Shih, F. Y.; Pan, C. L.

    2012-08-01

    The wavelength division multiplexing-time division multiplexing (WDM-TDM) passive optical network (PON) using reflective semiconductor optical amplifier (RSOA)-based colorless optical networking units (ONUs) is considered as a promising candidate for the realization of fiber-to-the-home (FTTH). And this architecture is actively considered by Industrial Technology Research Institute (ITRI) for the realization of FTTH in Taiwan. However, different fiber distances and optical components would introduce different power budgets to different ONUs in the PON. Besides, due to the aging of optical transmitter (Tx), the power decay of the distributed optical carrier from the central office (CO) could also reduce the injection power into each ONU. The situation will be more severe in the long-reach (LR) PON, which is considered as an option for the future access. In this work, we investigate a WDM-TDM PON using RSOA-based ONU for upstream data rate adjustment depending on different continuous wave (CW) injection powers. Both standard-reach (25 km) and LR (100 km) transmissions are evaluated. Moreover, a detail analysis of the upstream signal bit-error rate (BER) performances at different injection powers, upstream data rates, PON split-ratios under stand-reach and long-reach is presented.

  14. Model based manipulator control

    NASA Technical Reports Server (NTRS)

    Petrosky, Lyman J.; Oppenheim, Irving J.

    1989-01-01

    The feasibility of using model based control (MBC) for robotic manipulators was investigated. A double inverted pendulum system was constructed as the experimental system for a general study of dynamically stable manipulation. The original interest in dynamically stable systems was driven by the objective of high vertical reach (balancing), and the planning of inertially favorable trajectories for force and payload demands. The model-based control approach is described and the results of experimental tests are summarized. Results directly demonstrate that MBC can provide stable control at all speeds of operation and support operations requiring dynamic stability such as balancing. The application of MBC to systems with flexible links is also discussed.

  15. On-the-field performance of quintuple-play long-reach OFDM-based WDM-PON optical access networks.

    PubMed

    Llorente, Roberto; Morant, Maria; Pellicer, Eloy; Herman, Milan; Nagy, Zsolt; Alves, Tiago; Cartaxo, Adolfo; Herrera, Javier; Correcher, Jose; Quinlan, Terence; Walker, Stuart; Rodrigues, Cláudio; Cluzeaud, Pierre; Schmidt, Axel; Piesiewicz, Radoslaw; Sambaraju, Rakesh

    2014-03-24

    In this paper the on-the-field performance of a WDM-PON optical access providing quintuple-play services using orthogonal frequency division multiplexing (OFDM) modulation is evaluated in a real fiber-to-the-home (FTTH) network deployed by Towercom operator in Bratislava (Slovakia). A bundle of quintuple-play services comprising full-standard OFDM-based signals (LTE, WiMAX, UWB and DVB-T) and an ad-hoc OFDM-GbE signal is transmitted in coexistence per single user. Both downstream and upstream transmission performances are evaluated in different on-the-field long-reach optical link distance configurations. Four wavelength multi-user transmission of quintuple-play OFDM services is demonstrated exceeding 60.8 km reach in standard single mode fiber. PMID:24663968

  16. Mitigation of Rayleigh backscattering in 10-Gb/s downstream and 2.5-Gb/s upstream DWDM 100-km long-reach PONs.

    PubMed

    Chow, C W; Yeh, C H

    2011-03-14

    Long-reach passive optical network (LR-PON) is considered as a promising technology towards higher capacity and extended coverage optical system. We propose and demonstrate a LR-PON with the capability of Rayleigh backscattering (RB) noise mitigation. By using the upstream signal wavelength-transition generated by a dual-parallel Mach-Zehnder modulator (DP-MZM) based colorless optical networking unit (ONU), the spectral overlap among the upstream signal and the RB noises can be minimized. Hence, due to the achievement of effective RB mitigation, a 100 km LR-PON with a high split-ratio of 512 is demonstrated using 10 Gb/s non-return-to-zero (NRZ) downstream and 2.5 Gb/s NRZ upstream signals. Detail analysis of the wavelength-transition generation is presented. PMID:21445132

  17. REMOTELY OPERATED MANIPULATOR

    DOEpatents

    Hutto, E.L.

    1961-08-15

    A manipulator is described for performing, within an entirely enclosed cell containling radioactive materials, various mechanical operations. A rod with flexible fingers is encompassed by a tubular sleeve shorter than the rod. Relative movement between the rod and sleeve causes the fingers to open and close. This relative movement is effected by relative movement of permanent magnets in magnetic coupling relation to magnetic followers affixed to the ends of the rod and sleeve. The rod and its sleeve may be moved as a unit axially or may be rotated by means of the magnetic couplings. The manipulator is enclosed within a tubular member which is flexibly sealed to an opening in the cell. (AEC)

  18. Hydraulic manipulator research at ORNL

    SciTech Connect

    Kress, R.L.; Jansen, J.F.; Love, L.J.

    1997-03-01

    Recently, task requirements have dictated that manipulator payload capacity increase to accommodate greater payloads, greater manipulator length, and larger environmental interaction forces. General tasks such as waste storage tank cleanup and facility dismantlement and decommissioning require manipulator life capacities in the range of hundreds of pounds rather than tens of pounds. To meet the increased payload capacities demanded by present-day tasks, manipulator designers have turned once again to hydraulics as a means of actuation. In order to successfully design, build, and deploy a new hydraulic manipulator (or subsystem), sophisticated modeling, analysis, and control experiments are usually needed. Oak Ridge National Laboratory (ORNL) has a history of projects that incorporate hydraulics technology, including mobile robots, teleoperated manipulators, and full-scale construction equipment. In addition, to support the development and deployment of new hydraulic manipulators, ORNL has outfitted a significant experimental laboratory and has developed the software capability for research into hydraulic manipulators, hydraulic actuators, hydraulic systems, modeling of hydraulic systems, and hydraulic controls. The purpose of this article is to describe the past hydraulic manipulator developments and current hydraulic manipulator research capabilities at ORNL. Included are example experimental results from ORNL`s flexible/prismatic test stand.

  19. Robot Manipulators

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Space Shuttle's Remote Manipulator System (Canadarm) is a 50 foot robot arm used to deploy, retrieve or repair satellites in orbit. Initial spinoff version is designed to remove, inspect and replace large components of Ontario Hydro's CANDU nuclear reactors, which supply 50 percent of Ontario Hydro's total power reduction. CANDU robot is the first of SPAR's Remote Manipulator Systems intended for remote materials handling operations in nuclear servicing, chemical processing, smelting and manufacturing. Inco Limited used remote manipulator for remote control mining equipment to enhance safety and productivity of Inco's hardrock mining operations. System not only improves safety in a hazardous operation that costs more than a score of lives annually, it also increases productivity fourfold. Remote Manipulator System Division is also manufacturing a line of industrial robots and developing additional system for nuclear servicing, mining, defense and space operations.

  20. Demonstrations of 10 and 40 Gbps upstream transmissions using 1.2 GHz RSOA-based ONU in long-reach access networks

    NASA Astrophysics Data System (ADS)

    Yeh, C. H.; Chow, C. W.; Wu, Y. F.; Chen, H. Y.

    2012-03-01

    Carrier-distributed long-reach passive optical network (LR-PON) is a promising candidate for future access networks. In this work, we analyze and compare the 4 × 2.5 Gb/s and 4 × 10 Gb/s upstream traffics in a carrier-distributed LR-PON using four wavelength-multiplexed 2.5 Gb/s on-off keying (OOK) and 10 Gb/s optical orthogonal frequency division multiplexing-quadrature amplitude modulation (OFDM-QAM) signals. Four commercial 1.2 GHz bandwidth reflective semiconductor optical amplifiers (RSOAs) are used in each optical networking unit (ONU) for the generation of the upstream signal. Due to the limited bandwidth of the RSOA, only up to 2.5 Gb/s upstream OOK signal can be generated. However, by using the spectral efficient modulation, such as OFDM-QAM, 10 Gb/s data rate can be achieved. 20, 50 and 75 km fiber transmissions are also compared using the two different kinds of modulation respectively.

  1. Manipulation hardware for microgravity research

    SciTech Connect

    Herndon, J.N.; Glassell, R.L.; Butler, P.L.; Williams, D.M. ); Rohn, D.A. . Lewis Research Center); Miller, J.H. )

    1990-01-01

    The establishment of permanent low earth orbit occupation on the Space Station Freedom will present new opportunities for the introduction of productive flexible automation systems into the microgravity environment of space. The need for robust and reliable robotic systems to support experimental activities normally intended by astronauts will assume great importance. Many experimental modules on the space station are expected to require robotic systems for ongoing experimental operations. When implementing these systems, care must be taken not to introduce deleterious effects on the experiments or on the space station itself. It is important to minimize the acceleration effects on the experimental items being handled while also minimizing manipulator base reaction effects on adjacent experiments and on the space station structure. NASA Lewis Research Center has been performing research on these manipulator applications, focusing on improving the basic manipulator hardware, as well as developing improved manipulator control algorithms. By utilizing the modular manipulator concepts developed during the Laboratory Telerobotic Manipulator program, Oak Ridge National Laboratory has developed an experimental testbed system called the Microgravity Manipulator, incorporating two pitch-yaw modular positioners to provide a 4 dof experimental manipulator arm. A key feature in the design for microgravity manipulation research was the use of traction drives for torque transmission in the modular pitch-yaw differentials.

  2. Underwater manipulator

    SciTech Connect

    Schrum, P.B.; Cohen, G.H.

    1993-04-20

    Self-contained, waterproof, water-submersible, remote-controlled apparatus is described for manipulating a device, such as an ultrasonic transducer for measuring crack propagation on an underwater specimen undergoing shock testing. The subject manipulator includes metal bellows for transmittal of angular motions without the use of rotating shaft seals or O-rings. Inside the manipulator, a first stepper motor controls angular movement. In the preferred embodiment, the bellows permit the first stepper motor to move an ultrasonic transducer [plus minus]45 degrees in a first plane and a second bellows permit a second stepper motor to move the transducer [plus minus]10 degrees in a second plane orthogonal to the first. In addition, an XY motor-driven table provides XY motion.

  3. Underwater manipulator

    SciTech Connect

    Schrum, P.B.; Cohen, G.H.

    1992-12-31

    This invention is comprised of a self-contained, waterproof, water-submersible, remote-controlled apparatus provided for manipulating a device, such as an ultrasonic transducer for measuring crack propagation on an underwater specimen undergoing shock testing. The subject manipulator includes metal bellows for transmittal of angular motions without the use of rotating shaft seals or O-rings. Inside the manipulator, a first stepper motor controls angular movement. In the preferred embodiment, the bellows permit the first stepper motor to move an ultrasonic transducer {plus_minus} 45 degrees in a first plane and a second bellows permit a second stepper motor to move the transducer {plus_minus} 10 degrees in a second plane orthogonal to the first. In addition, an XY motor-driven table provides XY motion.

  4. Underwater manipulator

    DOEpatents

    Schrum, Phillip B.; Cohen, George H.

    1993-01-01

    Self-contained, waterproof, water-submersible, remote-controlled apparatus is provided for manipulating a device, such as an ultrasonic transducer for measuring crack propagation on an underwater specimen undergoing shock testing. The subject manipulator includes metal bellows for transmittal of angular motions without the use of rotating shaft seals or O-rings. Inside the manipulator, a first stepper motor controls angular movement. In the preferred embodiment, the bellows permit the first stepper motor to move an ultrasonic transducer .+-.45 degrees in a first plane and a second bellows permit a second stepper motor to move the transducer .+-.10 degrees in a second plane orthogonal to the first. In addition, an XY motor-driven table provides XY motion.

  5. FARMS: The Flexible Agricultural Robotics Manipulator

    NASA Technical Reports Server (NTRS)

    Gill, Paul S.

    1991-01-01

    A technology utilization project was established with the Marshall Space Flight Center and the University of Georgia to develop an Earth-based, robotic end effector to process live plant (geranium) material which will improve productivity and efficiency in agricultural systems such as commercial nurseries and greenhouse systems. The aim is to apply this technology to NASA's presence in space, including permanently manned space stations and manned planetary communities requiring large scale food production needs.

  6. Remote Manipulator

    NASA Technical Reports Server (NTRS)

    1986-01-01

    SPAR Aerospace Limited's "Canadarm," Canada's contribution to the space shuttle. It is a crane which can operate as a 50 foot extension of an astronaut's arm. It can lift 65,000 pounds in space and retrieve satellites for repair, etc. Redesigned versions have energy and mining applications. Some of its hardware has been redeveloped for use as a Hydro manipulator in a nuclear reactor where it is expected to be extremely cost effective.

  7. Manipulation strategies for massive space payloads

    NASA Technical Reports Server (NTRS)

    Book, Wayne J.

    1991-01-01

    The industrial and environmental applications for robots with a relatively large workspace has increased significantly in the last few years. To accommodate the demands, the manipulator is usually designed with long, lightweight links that are inherently flexible. Ongoing research at Georgia Tech into the behavior and design of these flexible links is discussed.

  8. Flexible transformation plasmonics using graphene.

    PubMed

    Lu, Wei Bing; Zhu, Wei; Xu, Hong Ju; Ni, Zhen Hua; Dong, Zheng Gao; Cui, Tie Jun

    2013-05-01

    The flexible control of surface plasmon polaritons (SPPs) is important and intriguing due to its wide application in novel plasmonic devices. Transformation optics (TO) offers the capability either to confine the SPP propagation on rigid curved/uneven surfaces, or to control the flow of SPPs on planar surfaces. However, TO has not permitted us to confine, manipulate, and control SPP waves on flexible curved surfaces. Here, we propose to confine and freely control flexible SPPs using TO and graphene. We show that SPP waves can be naturally confined and propagate on curved or uneven graphene surfaces with little bending and radiation losses, and the confined SPPs are further manipulated and controlled using TO. Flexible plasmonic devices are presented, including the bending waveguides, wave splitter, and Luneburg lens on curved surfaces. Together with the intrinsic flexibility, graphene can be served as a good platform for flexible transformation plasmonics. PMID:23669904

  9. Tradeoffs in manipulator structure and control. Part 1: Summary

    NASA Technical Reports Server (NTRS)

    Whitney, D. E.; Book, W. J.; Maizza-Neto, O.

    1974-01-01

    The study of various aspects of manipulator design and control is summarized, focusing on the interaction of the structure's flexible dynamics and the dynamics of the joint control system, including specific information on modeling and design, modal analysis and control, and the flexible manipulator analysis computer program, FMAP.

  10. Research on a reconfigurable modular manipulator system

    NASA Astrophysics Data System (ADS)

    Khosla, P. K.; Kanade, T.

    Research has been conducted on developing the theoretical basis and the technology for a Reconfigurable Modular Manipulation System (RMMS). Unlike a conventional manipulator which has a fixed configuration, the RMMS consists of a set of interchangeable modules that can be rapidly assembled into a system of manipulators with appropriate configurations depending on the specific task requirement. For effective development and use of such a versatile and flexible system a program of theoretical and experimental research has been pursued aimed at developing the basis for next generation of autonomous manipulator systems. The RMMS concept extends the idea of autonomy from sensor-based to configuration based autonomy. One of the important components is the development of design methodologies for mapping tasks into manipulator configurations and for automatic generation of manipulator specific algorithms (e.g., kinematics and dynamics) in order to make the hardware transparent to the user.

  11. Research on a Reconfigurable Modular Manipulator System

    SciTech Connect

    Khosla, P.K.; Kanade, T.

    1992-01-01

    Research has been conducted on developing the theoretical basis and the technology for a Reconfigurable Modular Manipulation System (RMMS). Unlike a conventional manipulator which has a fixed configuration, the RMMS consists of a set of interchangeable modules that can be rapidly assembled into a system of manipulators with appropriate configurations depending on the specific task requirement. For effective development and use of such a versatile and flexible system a program of theoretical and experimental research has been pursued aimed at developing the basis for next generation of autonomous manipulator systems. The RMMS concept extends the idea of autonomy from sensor-based to configuration based autonomy. One of the important components is the development of design methodologies for mapping tasks into manipulator configurations and for automatic generation of manipulator specific algorithms (e.g., kinematics and dynamics) in order to make the hardware transparent to the user.(JDB)

  12. Manipulating Representations.

    PubMed

    Recchia-Luciani, Angelo N M

    2012-04-01

    The present paper proposes a definition for the complex polysemic concepts of consciousness and awareness (in humans as well as in other species), and puts forward the idea of a progressive ontological development of consciousness from a state of 'childhood' awareness, in order to explain that humans are not only able to manipulate objects, but also their mental representations. The paper builds on the idea of qualia intended as entities posing regular invariant requests to neural processes, trough the permanence of different properties. The concept of semantic differential introduces the properties of metaphorical qualia as an exclusively human ability. Furthermore this paper proposes a classification of qualia, according to the models-with different levels of abstraction-they are implied in, in a taxonomic perspective. This, in turn, becomes a source of categorization of divergent representations, sign systems, and forms of intentionality, relying always on biological criteria. New emerging image-of-the-world-devices are proposed, whose qualia are likely to be only accessible to humans: emotional qualia, where emotion accounts for the invariant and dominant property; and the qualic self where continuity, combined with the oneness of the self, accounts for the invariant and dominant property. The concept of congruence between different domains in a metaphor introduces the possibility of a general evaluation of truth and falsity of all kinds of metaphorical constructs, while the work of Matte Blanco enables us to classify conscious versus unconscious metaphors, both in individuals and in social organizations. PMID:22347988

  13. An analysis of the kinematics and dynamics of underactuated manipulators

    SciTech Connect

    Jain, A.; Rodriguez, G.

    1993-08-01

    The dynamics and kinematics of manipulators that have fewer actuators than degrees of freedom are studied. These underactuated manipulators arise in a number of important applications such as free-flying space robots, hyperredundant manipulators, manipulators with structural flexibility, etc. In the analysis such underactuated manipulators are decomposed into component active and passive arms. This decomposition allows techniques previously developed for regular (fully actuated) manipulators to be applied to underactuated systems. Spatial operator identities are used to develop closed-form expressions for the generalized accelerations for the system. These expressions form the basis for a recursive dynamics algorithm. The structure of this algorithm is a hybrid of known forward and inverse dynamics algorithms for regular manipulators. Expressions and computational algorithms are also developed for the generalized and disturbance Jacobians for underactuated manipulators. The application of the results in the paper to space manipulators is also described.

  14. KINEMATIC ANALYSIS OF MODULAR, TRUSS-BASED MANIPULATOR UNITS

    SciTech Connect

    Salerno, R. J.

    1994-06-01

    Decontamination and Dismantling (D&D) activities within the U.S. Department of Energy (DOE) require a long reach manipulator with a large load capacity. Variable Geometry Trusses (VGTs) are a unique class of mechanical structures which allow the advantages of truss structures for large scale applications to be applied to large robotic manipulators. Individual VGT units may be assembled to create a modular, long-reach, truss-type manipulator. Each module of such a manipulator system is either a static truss section or one of several possible VGT geometries. While many potential applications exist for this technology, the present work is largely motivated by the need for generic robotic systems for remote manipulation. A manipulator system based on VGT modules provides several advantages. The reconfigurable nature of the manipulator system allows it to be adapted on site to unforeseen conditions. The kinematic redundancy of the manipulator enables it to work effectively even in a highly obstructed workspace. The parallel structure of the truss modules enables the manipulator to be withdrawn in the event of a structural failure. Finally, the open framework of the modules provides a clear, protected passageway for control and power cabling, waste conveyance, or other services required at the end effector. As is implied in a truss structure, all primary members of a VGT are ideally loaded in pure tension or compression. This results in an extremely stiff and strong manipulator system with minimal overall weight. Careful design of the joints of a VGT is very important to the overall stiffness and accuracy of the structure, as several links (as many as six) are joined together at each joint. The greatest disadvantage to this approach to manipulator design has traditionally been that the kinematics of VGT structures are complex and poorly understood. This report specifically addresses the kinematics of several possible geometries for the individual VGT units. Equations and

  15. Active damping of oscillations in a long compliant manipulator link

    NASA Astrophysics Data System (ADS)

    Baker, C. P.; Evans, M. S.; Trudnowski, D. J.; Magee, D. P.

    1993-07-01

    A flexible manipulator test bed consisting of a fifteen foot long fixed-free compliant beam (representing a compliant manipulator link) with a Shilling Titan II dextrous manipulator mounted on its free end has been constructed at Pacific Northwest Laboratory (PNL). A comprehensive dynamic model which includes flexible body effects has been developed at PNL using a commercially available multibody dynamics code. A linearized version of the model is used to develop control strategies which use inertial forces generated by movements of the dextrous manipulator to damp out induced oscillations in the beam. These control strategies are tested on the model and shown to be feasible, and then implemented in the flexible manipulator testbed. Results from the hardware experiments are analyzed and compared with the model results.

  16. The Long Reach of Teachers Unions

    ERIC Educational Resources Information Center

    Antonucci, Mike

    2010-01-01

    The largest political campaign spender in America is not a megacorporation, such as Wal-Mart, Microsoft, or ExxonMobil. It isn't an industry association, like the American Bankers Association or the National Association of Realtors. It's not even a labor federation, like the AFL-CIO. If one combines the campaign spending of all those entities it…

  17. Dynamic Analysis of a Two Member Manipulator

    NASA Technical Reports Server (NTRS)

    McGinley, W. Mark; Shen, Ji Y.

    1997-01-01

    Attenuating start-up and stopping vibrations when maneuvering large payloads attached to flexible manipulator systems is a great concern for many space missions. To address this concern, it was proposed that the use of smart materials, and their applications in smart structures, may provide an effective method of control for aerospace structures. In this paper, a modified finite element model has been developed to simulate the performance of piezoelectric ceramic actuators, and was applied to a flexible two-arm manipulator system. Connected to a control voltage, the piezoelectric actuators produce control moments based on the optimal control theory. The computer simulation modeled the end-effector vibration suppression of the NASA manipulator testbed for berthing operations of the Space Shuttle to the Space Station. The results of the simulation show that the bonded piezoelectric actuators can effectively suppress follow-up vibrations of the end-effector, stimulated by some external disturbance.

  18. Large-area Overhead Manipulator for Access of Fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multi-axis, cable-driven manipulators have evolved over many years providing large area suspended platform access, programmability, relatively rigid and flexibly-positioned platform control and full six degree of freedom (DOF) manipulation of sensors and tools. We describe innovations for a new six...

  19. MODULAR MANIPULATOR FOR ROBOTICS APPLICATIONS

    SciTech Connect

    Joseph W. Geisinger, Ph.D.

    2001-07-31

    ARM Automation, Inc. is developing a framework of modular actuators that can address the DOE's wide range of robotics needs. The objective of this effort is to demonstrate the effectiveness of this technology by constructing a manipulator from these actuators within a glovebox for Automated Plutonium Processing (APP). At the end of the project, the system of actuators was used to construct several different manipulator configurations, which accommodate common glovebox tasks such as repackaging. The modular nature and quickconnects of this system simplify installation into ''hot'' boxes and any potential modifications or repair therein. This work focused on the development of self-contained robotic actuator modules including the embedded electronic controls for the purpose of building a manipulator system. Both of the actuators developed under this project contain the control electronics, sensors, motor, gear train, wiring, system communications and mechanical interfaces of a complete robotics servo device. Test actuators and accompanying DISC{trademark}s underwent validation testing at The University of Texas at Austin and ARM Automation, Inc. following final design and fabrication. The system also included custom links, an umbilical cord, an open architecture PC-based system controller, and operational software that permitted integration into a completely functional robotic manipulator system. The open architecture on which this system is based avoids proprietary interfaces and communication protocols which only serve to limit the capabilities and flexibility of automation equipment. The system was integrated and tested in the contractor's facility for intended performance and operations. The manipulator was tested using the full-scale equipment and process mock-ups. The project produced a practical and operational system including a quantitative evaluation of its performance and cost.

  20. 40 Gb/s on-off keying downstream and 10 Gb/s on-off keying remodulated upstream signals in long-reach access network with multivideo services

    NASA Astrophysics Data System (ADS)

    Yeh, Chien-Hung; Chow, Chi-Wai; Liu, Yen-Liang; Pan, Ci-Ling

    2011-12-01

    In this demonstration, we propose and investigate a long reach passive optical network (PON) using four wavelength-multiplexed signals with both on-off keying modulations for 40 Gb/s downlink traffic in 100 km fiber transmission without dispersion compensation. In the exchange node, we can use four channels with video services broadcasting to each optical network unit (ONU) for the uplink signal remodulation. Hence, four wavelength-multiplexed video signals also can be used to inject into the corresponding reflective semiconductor optical amplifiers in each ONU for uplink signal remodulation to achieve a 4 × 2.5 Gb/s data rate. In addition, under the 32 split ratio PON system, the power penalties of nearly 6.7 and 1 dB could be measured at the bit error rate of 10-9 for the downlink and uplink traffic, respectively.

  1. Flexibility Program

    ERIC Educational Resources Information Center

    Connors, G. Patrick

    These brief guidelines for a muscular flexibility program state that the purpose of such a program is to increase the range of motion in order to avoid injuries and eliminate awkwardness in physical activities. A flexibility program is described as an extension of the warm-up period and should be an ongoing, permanent effort to lengthen muscles. A…

  2. Flexible Scheduling.

    ERIC Educational Resources Information Center

    Davis, Harold S.; Bechard, Joseph E.

    A flexible schedule allows teachers to change group size, group composition, and class length according to the purpose of the lesson. This pamphlet presents various "master" schedules for flexible scheduling: (1) Simple block schedules, (2) back-to-back schedules, (3) interdisciplinary schedules, (4) school-wide block schedules, (5) open-lab…

  3. Mobile Remote Manipulator

    NASA Technical Reports Server (NTRS)

    Coryell, S.; Olsen, R. E.

    1986-01-01

    Turret, roll arm, and trolley enhance manipulator dexterity. Remote manipulator moves on trolley base along structure. Roll-axis arm positions manipulator arm so it can extend end effector under structure. Yaw-axis rotation gives added reach to arm above structure. Designed for handling, inspecting, and maintaining modules of space station. Manipulators having such capabilities useful on Earth; robots in manufacturing, erection of large structures, or performing complicated tasks in hazardous locations.

  4. Progress in nonprehensile manipulation

    SciTech Connect

    Mason, M.T.

    1999-11-01

    This paper reviews my recent research in robotic manipulation and speculates on potentially fruitful directions for future work. My recent work is focused on nonprehensile manipulation: manipulating objects without grasping them. In particular, the paper surveys work on a single joint robot that orients parts on a conveyor belt; a robot that uses dynamics to snatch, roll, or throw objects; hitting things to position them; manipulating things whose shapes are not completely known; and integration of manipulation with locomotion. In the future, a broad view of robotics will allow us to focus on fundamental principles and at the same time address a variety of new applications.

  5. Manipulator for rotating and examining small spheres

    DOEpatents

    Weinstein, Berthold W. [Livermore, CA; Willenborg, David L. [Livermore, CA

    1980-02-12

    A manipulator which provides fast, accurate rotational positioning of a small sphere, such as an inertial confinement fusion target, which allows inspecting of the entire surface of the sphere. The sphere is held between two flat, flexible tips which move equal amounts in opposite directions. This provides rolling of the ball about two orthogonal axes without any overall translation. The manipulator may be controlled, for example, by an x- and y-axis driven controlled by a mini-computer which can be programmed to generate any desired scan pattern.

  6. Manipulator for rotating and examining small spheres

    DOEpatents

    Weinstein, B.W.; Willenborg, D.L.

    1980-02-12

    A manipulator is disclosed which provides fast, accurate rotational positioning of a small sphere, such as an inertial confinement fusion target, which allows inspecting of the entire surface of the sphere. The sphere is held between two flat, flexible tips which move equal amounts in opposite directions. This provides rolling of the ball about two orthogonal axes without any overall translation. The manipulator may be controlled, for example, by an x- and y-axis driven controlled by a mini-computer which can be programmed to generate any desired scan pattern. 8 figs.

  7. Experimental validation of flexible robot arm modeling and control

    NASA Technical Reports Server (NTRS)

    Ulsoy, A. Galip

    1989-01-01

    Flexibility is important for high speed, high precision operation of lightweight manipulators. Accurate dynamic modeling of flexible robot arms is needed. Previous work has mostly been based on linear elasticity with prescribed rigid body motions (i.e., no effect of flexible motion on rigid body motion). Little or no experimental validation of dynamic models for flexible arms is available. Experimental results are also limited for flexible arm control. Researchers include the effects of prismatic as well as revolute joints. They investigate the effect of full coupling between the rigid and flexible motions, and of axial shortening, and consider the control of flexible arms using only additional sensors.

  8. Structural Sizing Methodology for the Tendon-Actuated Lightweight In-Space MANipulator (TALISMAN) System

    NASA Technical Reports Server (NTRS)

    Jones, Thomas C.; Dorsey, John T.; Doggett, William R.

    2015-01-01

    The Tendon-Actuated Lightweight In-Space MANipulator (TALISMAN) is a versatile long-reach robotic manipulator that is currently being tested at NASA Langley Research Center. TALISMAN is designed to be highly mass-efficient and multi-mission capable, with applications including asteroid retrieval and manipulation, in-space servicing, and astronaut and payload positioning. The manipulator uses a modular, periodic, tension-compression design that lends itself well to analytical modeling. Given the versatility of application for TALISMAN, a structural sizing methodology was developed that could rapidly assess mass and configuration sensitivities for any specified operating work space, applied loads and mission requirements. This methodology allows the systematic sizing of the key structural members of TALISMAN, which include the truss arm links, the spreaders and the tension elements. This paper summarizes the detailed analytical derivations and methodology that support the structural sizing approach and provides results from some recent TALISMAN designs developed for current and proposed mission architectures.

  9. Low-peak-to-average power ratio and low-complexity asymmetrically clipped optical orthogonal frequency-division multiplexing uplink transmission scheme for long-reach passive optical network.

    PubMed

    Zhou, Ji; Qiao, Yaojun

    2015-09-01

    In this Letter, we propose a discrete Hartley transform (DHT)-spread asymmetrically clipped optical orthogonal frequency-division multiplexing (DHT-S-ACO-OFDM) uplink transmission scheme in which the multiplexing/demultiplexing process also uses the DHT algorithm. By designing a simple encoding structure, the computational complexity of the transmitter can be reduced from O(Nlog(2)(N)) to O(N). At the probability of 10(-3), the peak-to-average power ratio (PAPR) of 2-ary pulse amplitude modulation (2-PAM)-modulated DHT-S-ACO-OFDM is approximately 9.7 dB lower than that of 2-PAM-modulated conventional ACO-OFDM. To verify the feasibility of the proposed scheme, a 4-Gbit/s DHT-S-ACO-OFDM uplink transmission scheme with a 1∶64 way split has been experimentally implemented using 100-km standard single-mode fiber (SSMF) for a long-reach passive optical network (LR-PON). PMID:26368705

  10. Flexible cystoscopy.

    PubMed

    Kennedy, T J; Preminger, G M

    1988-08-01

    Flexible fiberoptic technology was first applied to cystoscopy in 1973, with greatly increased usage since 1982. Most procedures formerly performed with rigid cystoscopes can be done using flexible cystoscopes with minimal or no anesthesia. Patient positioning and precystocopy preparation and draping are simplified with the flexible fiberoptic instruments. Complete examination of the urethra and bladder can be performed with a single-lens system and with the patient in a variety of positions. Fiberoptic cystoscopy is limited in patients who are bleeding or have blood clots in their bladders. Withdrawal of irrigant or bladder drainage is cumbersome, and the fiberoptic image is currently not of the same caliber as that of the rigid-lens systems. Fiberoptic cystoscopy has become the procedure of choice for many urologists for ureteral stenting prior to extracorporeal shock-wave lithotripsy. With the advent of lithotripters that require no anesthesia, this application is likely to broaden. Future applications of flexible cystoscopy may include a flexible videocystoscope for use in diagnostic and therapeutic procedures. PMID:3407042

  11. Piping Flexibility

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A NASA computer program aids Hudson Engineering Corporation, Houston, Texas, in the design and construction of huge petrochemical processing plants like the one shown, which is located at Ju'aymah, Saudi Arabia. The pipes handling the flow of chemicals are subject to a variety of stresses, such as weight and variations in pressure and temperature. Hudson Engineering uses a COSMIC piping flexibility analysis computer program to analyze stresses and unsure the necessary strength and flexibility of the pipes. This program helps the company realize substantial savings in reduced engineering time.

  12. SNAKES manipulator and ARD sluicer testing -- April 1997

    SciTech Connect

    Berglin, E.J.

    1997-05-29

    Long reach arms represent one of the options available for deployment of end effectors which can be used in the retrieval of radioactive waste, from the Hanford single shell tanks. The versatility of an arm based deployment system is such that it has the potential to improve the performance of a wide range of end effectors compared with stand-alone or other deployment methods. The long term reliability and availability of the deployment system is central to the timely completion of a waste retrieval program. However, concerns have been expressed over the dynamic performance of long reach arms and it is essential that an arm based system can cope with operational dynamic loads generated by end effectors. The test program conducted set out to measure static and dynamic loads and responses from a representative arm and sluicer, with the objective of extrapolating the data to a long reach arm system, that can be used for in-tank waste retrieval. As an arm with an appropriate reach was not available, the test program was undertaken to measure dynamic characteristics of a Magnox Electric 18 ft multi-link, hydraulically actuated SNAKES manipulator. This is the longest reach unit in service, albeit only one third of the 50 ft length required for in-tank waste retrieval. In addition operational performance and loading measurements were obtained from a low pressure confined system sluicer under development by ARD Environmental, to add to the end effector data base. When subject to impulse loading, the arm was found to behave in a repeatable manner having fundamental natural frequencies in the vertical and transverse directions of 1 Hz. There were also a large number of higher natural frequencies measured up to 100 Hz.

  13. Direct Manipulation Interfaces.

    ERIC Educational Resources Information Center

    Hutchins, Edwin L.; And Others

    This paper presents a cognitive account of both the advantages and disadvantages of direct manipulation interfaces, i.e., the use of icons to manipulate and interact directly with data rather than writing programs or calling on a set of statistical subroutines. Two underlying phenomena that give rise to the sensation of directness are identified.…

  14. Revisiting Mathematics Manipulative Materials

    ERIC Educational Resources Information Center

    Swan, Paul; Marshall, Linda

    2010-01-01

    It is over 12 years since "APMC" published Bob Perry and Peter Howard's research on the use of mathematics manipulative materials in primary mathematics classrooms. Since then the availability of virtual manipulatives and associated access to computers and interactive whiteboards have caused educators to rethink the use of mathematics manipulative…

  15. Manipulator comparative testing program

    SciTech Connect

    Draper, J.V.; Handel, S.J.; Sundstrom, E.; Herndon, J.N.; Fujita, Y.; Maeda, M.

    1986-01-01

    The Manipulator Comparative Testing Program examined differences among manipulator systems from the United States and Japan. The manipulator systems included the Meidensha BILARM 83A, the Model M-2 of Central Research Laboratories Division of Sargent Industries (CRL), and the GCA Corporation PaR Systems Model 6000. The site of testing was the Remote Operations Maintenance Demonstration (ROMD) facility, operated by the Fuel Recycle Division in the Consolidated Fuel Reprocessing Program at the Oak Ridge National Laboratory (ORNL). In all stages of testing, operators using the CRL Model M-2 manipulator had consistently lower times to completion and error rates than they did using other machines. Performance was second best with the Meidensha BILARM 83A in master-slave mode. Performance with the BILARM in switchbox mode and the PaR 6000 manipulator was approximately equivalent in terms of criteria recorded in testing. These data show no impact of force reflection on task performance.

  16. Osteopathic Manipulative Treatment

    PubMed Central

    Campbell, Shannon M.; Walkowski, Stevan

    2012-01-01

    Dermatological diseases, such as dysesthesia syndromes, stasis dermatoses, and hyperhidrosis are difficult to treat due to their complex etiologies. Current theories suggest these diseases are caused by physiological imbalances, such as nerve impingement, localized tissue congestion, and impaired autonomic regulation. Osteopathic manipulative therapy targets these physiological dysfunctions and may serve as a beneficial therapeutic option. Osteopathic manipulative therapy techniques include high velocity low amplitude, muscle energy, counterstrain, myofascial release, craniosacral, and lymphatic drainage. An osteopathic manipulative therapy technique is chosen based on its physiological target for a particular disease. Osteopathic manipulative therapy may be useful alone or in combination with standard therapeutic options. However, due to the lack of standardized trials supporting the efficacy of osteopathic manipulative therapy treatment for dermatological disease, randomized, well-controlled studies are necessary to confirm its therapeutic value. PMID:23125887

  17. Self mobile space manipulator project

    NASA Astrophysics Data System (ADS)

    Brown, H. Ben; Friedman, Mark; Xu, Yangsheng; Kanade, Takeo

    1992-01-01

    A relatively simple, modular, low mass, low cost robot is being developed for space EVA that is large enough to be independently mobile on a space station or platform exterior, yet versatile enough to accomplish many vital tasks. The robot comprises two long flexible links connected by a rotary joint, with 2-DOF 'wrist' joints and grippers at each end. It walks by gripping pre-positioned attachment points, such as trusswork nodes, and alternately shifting its base of support from one foot (gripper) to the other. The robot can perform useful tasks such as visual inspection, material transport, and light assembly by manipulating objects with one gripper, while stabilizing itself with the other. At SOAR '90, we reported development of 1/3 scale robot hardware, modular trusswork to serve as a locomotion substrate, and a gravity compensation system to allow laboratory tests of locomotion strategies on the horizontal face of the trusswork. In this paper, we report on project progress including the development of: (1) adaptive control for automatic adjustment to loads; (2) enhanced manipulation capabilities; (3) machine vision, including the use of neural nets, to guide autonomous locomotion; (4) locomotion between orthogonal trusswork faces; and (5) improved facilities for gravity compensation and telerobotic control.

  18. Update: Biochemistry of Genetic Manipulation.

    ERIC Educational Resources Information Center

    Barker, G. R.

    1983-01-01

    Various topics on the biochemistry of genetic manipulation are discussed. These include genetic transformation and DNA; genetic expression; DNA replication, repair, and mutation; technology of genetic manipulation; and applications of genetic manipulation. Other techniques employed are also considered. (JN)

  19. Osteopathic Manipulative Treatment

    MedlinePlus

    ... what patients really need is a healing touch. Osteopathic physicians haven't forgotten. Osteopathic manipulative treatment, or OMT, ... and prevent illness or injury. Using OMT, your osteopathic physician will move your muscles and joints using techniques ...

  20. Dielectrophoresis for bioparticle manipulation.

    PubMed

    Qian, Cheng; Huang, Haibo; Chen, Liguo; Li, Xiangpeng; Ge, Zunbiao; Chen, Tao; Yang, Zhan; Sun, Lining

    2014-01-01

    As an ideal method to manipulate biological particles, the dielectrophoresis (DEP) technique has been widely used in clinical diagnosis, disease treatment, drug development, immunoassays, cell sorting, etc. This review summarizes the research in the field of bioparticle manipulation based on DEP techniques. Firstly, the basic principle of DEP and its classical theories are introduced in brief; Secondly, a detailed introduction on the DEP technique used for bioparticle manipulation is presented, in which the applications are classified into five fields: capturing bioparticles to specific regions, focusing bioparticles in the sample, characterizing biomolecular interaction and detecting microorganism, pairing cells for electrofusion and separating different kinds of bioparticles; Thirdly, the effect of DEP on bioparticle viability is analyzed; Finally, the DEP techniques are summarized and future trends in bioparticle manipulation are suggested. PMID:25310652

  1. Classifying human manipulation behavior.

    PubMed

    Bullock, Ian M; Dollar, Aaron M

    2011-01-01

    This paper presents a taxonomy for detailed classification of human and anthropomorphic manipulation behavior. This hand-centric, motion-centric taxonomy differentiates tasks based on criteria such as object contact, prehension, and the nature of object motion relative to a hand frame. A sub-classification of the most dexterous categories, within-hand manipulation, is also presented, based on the principal axis of object rotation or translation in the hand frame. Principles for categorizing complex, multi-faceted tasks are also presented, along with illustrative examples. We hope that the proposed taxonomy will both establish a standard language around human and anthropomorphic manipulation as well as enable improved understanding of the differences in hand use for a wide variety of behavior. Although designed for human and anthropomorphic hands, the taxonomy might easily be extended to a wide range of robot manipulators and end-effectors. PMID:22275611

  2. Dielectrophoresis for Bioparticle Manipulation

    PubMed Central

    Qian, Cheng; Huang, Haibo; Chen, Liguo; Li, Xiangpeng; Ge, Zunbiao; Chen, Tao; Yang, Zhan; Sun, Lining

    2014-01-01

    As an ideal method to manipulate biological particles, the dielectrophoresis (DEP) technique has been widely used in clinical diagnosis, disease treatment, drug development, immunoassays, cell sorting, etc. This review summarizes the research in the field of bioparticle manipulation based on DEP techniques. Firstly, the basic principle of DEP and its classical theories are introduced in brief; Secondly, a detailed introduction on the DEP technique used for bioparticle manipulation is presented, in which the applications are classified into five fields: capturing bioparticles to specific regions, focusing bioparticles in the sample, characterizing biomolecular interaction and detecting microorganism, pairing cells for electrofusion and separating different kinds of bioparticles; Thirdly, the effect of DEP on bioparticle viability is analyzed; Finally, the DEP techniques are summarized and future trends in bioparticle manipulation are suggested. PMID:25310652

  3. Dexterous manipulator flight demonstration

    NASA Technical Reports Server (NTRS)

    Carter, Edward L.

    1989-01-01

    The Dexterous Manipulator Flight Experiment, an outgrowth of the Dexterous End Effector project, is an experiment to demonstrate newly developed equipment and methods that make for a dexterous manipulator which can be used on the Space Shuttle or other space missions. The goals of the project, the objectives of the flight experiment, the experiment equipment, and the tasks to be performed during the demonstration are discussed.

  4. Remote manipulator dynamic simulation

    NASA Technical Reports Server (NTRS)

    Wild, E. C.; Donges, P. K.; Garand, W. A.

    1972-01-01

    A simulator to generate the real time visual scenes required to perform man in the loop investigations of remote manipulator application and design concepts for the space shuttle is described. The simulated remote manipulator consists of a computed display system that uses a digital computer, the electronic scene generator, an operator's station, and associated interface hardware. A description of the capabilities of the implemented simulation is presented. The mathematical models and programs developed for the simulation are included.

  5. Flexible quadrature amplitude modulation with semiconductor optical amplifier and electroabsorption modulator.

    PubMed

    Schrenk, Bernhard; Dris, Stefanos; Bakopoulos, Paraskevas; Lazarou, Ioannis; Voigt, Karsten; Zimmermann, Lars; Avramopoulos, Hercules

    2012-08-01

    Optical quadrature amplitude modulation (QAM) is experimentally demonstrated with a low-complexity modulator based on a semiconductor optical amplifier and electroabsorption modulator. Flexible amplitude/phase format transmission is achieved. The applicability of octary QAM for coherent optical access networks with sustainable 3 Gb/s per-user bandwidth is investigated for a long reach of 100 km, and its compatibility with a potentially high split is verified. PMID:22859139

  6. Flexible shielding system for radiation protection

    NASA Technical Reports Server (NTRS)

    Babin, A.

    1972-01-01

    Modular construction of low cost flexible radiation shielding panels consists of water filled steels cans, zinc bromide windows, turntable unit, master-slave manipulators, and interlocking lead bricks. Easy modifications of shielding wall thicknesses are obtained by rearranging overall geometry of portable components.

  7. Atlas based kinematic optimum design of the Stewart parallel manipulator

    NASA Astrophysics Data System (ADS)

    Shao, Zhufeng; Tang, Xiaoqiang; Wang, Liping; Sun, Dengfeng

    2015-01-01

    Optimum design is a key approach to make full use of potential advantages of a parallel manipulator. The optimum design of multi-parameter parallel manipulators(more than three design parameters), such as Stewart manipulator, relies on analysis based and algorithm based optimum design methods, which fall to be accurate or intuitive. To solve this problem and achieve both accurate and intuition, atlas based optimum design of a general Stewart parallel manipulator is established, with rational selection of design parameters. Based on the defined spherical usable workspace(SUW), primary kinematic performance indices of the Stewart manipulator, involving workspace and condition number are introduced and analyzed. Then, corresponding performance atlases are drawn with the established non-dimensional design space, and impact of joint distribution angles on the manipulator performance is analyzed and illustrated. At last, an example on atlas based optimum design of the Stewart manipulator is accomplished to illustrate the optimum design process, considering the end-effector posture. Deduced atlases can be flexibly applied to both quantitative and qualitative analysis to get the desired optimal design for the Stewart manipulator with respect to related performance requirements. Besides, the established optimum design method can be further applied to other multi-parameter parallel manipulators.

  8. Manipulator comparative testing program

    SciTech Connect

    Draper, J.V.; Handel, S.J.; Sundstrom, E.; Herndon, J.N.; Fujita, Y.; Maida, M.

    1986-01-01

    The Manipulator Comparative Testing Program compared performance of selected manipulator systems under typical remote handling conditions. The site of testing was the Remote Operations and Maintenance Demonstration Facility operated by the Consolidated Fuel Reprocessing Program of the Oak Ridge National Laboratory. Three experiment examined differences among manipulator systems from the US and Japan. The manipulator systems included the Meidensha BILARM 83A, Central Research Laboratories' (CRL's) Model M-2, and GCA PaR systems Model 6000. Six manipulator and control mode combinations were evaluated: (a) the BILARM in master-slave mode without force reflection; (b) the BILARM in master-slave mode with force reflection; (c) the Model M-2 in master-slave mode without force reflection; (d) the Model M-2 in master-slave mode with force reflection; (e) the BILARM with switchbox controls; and (f) the PaR 6000 with switchbox controls. The experiments also examined differences between master-slave systems with and without force reflections, and differences between master-slave systems and switchbox-controlled systems.

  9. FLEXIBLE COUPLING

    DOEpatents

    Babelay, E.F.

    1962-02-13

    A flexible shaft coupling for operation at speeds in excess of 14,000 rpm is designed which requires no lubrication. A driving sleeve member and a driven sleeve member are placed in concentric spaced relationship. A torque force is transmitted to the driven member from the driving member through a plurality of nylon balls symmetrically disposed between the spaced sleeves. The balls extend into races and recesses within the respective sleeve members. The sleeve members have a suitable clearance therebetween and the balls have a suitable radial clearance during operation of the coupling to provide a relatively loose coupling. These clearances accommodate for both parallel and/or angular misalignments and avoid metal-tometal contact between the sleeve members during operation. Thus, no lubrication is needed, and a minimum of vibrations is transmitted between the sleeve members. (AEC)

  10. ELECTRONIC MASTER SLAVE MANIPULATOR

    DOEpatents

    Goertz, R.C.; Thompson, Wm.M.; Olsen, R.A.

    1958-08-01

    A remote control manipulator is described in which the master and slave arms are electrically connected to produce the desired motions. A response signal is provided in the master unit in order that the operator may sense a feel of the object and may not thereby exert such pressures that would ordinarily damage delicate objects. This apparatus will permit the manipulation of objects at a great distance, that may be viewed over a closed TV circuit, thereby permitting a remote operator to carry out operations in an extremely dangerous area with complete safety.

  11. Control strategy for cooperating disparate manipulators

    NASA Technical Reports Server (NTRS)

    Lew, Jae Young

    1989-01-01

    To manipulate large payloads typical of space construction, the concept of a small arm mounted on the end of a large arm is introduced. The main purposes of such a configuration are to increase the structural stiffness of the robot by bracing against or locking to a stationary frame, and to maintain a firm position constraint between the robot's base and workpieces by grasping them. Possible topologies for a combination of disparate large and small arms are discussed, and kinematics, dynamics, controls, and coordination of the two arms, especially when they brace at the tip of the small arm, are developed. The feasibility and improvement in performance are verified, not only with analytical work and simulation results but also with experiments on the existing arrangement Robotic Arm Large and Flexible and Small Articulated Manipulator.

  12. Graphene plasmonic lens for manipulating energy flow

    NASA Astrophysics Data System (ADS)

    Wang, Guoxi; Liu, Xueming; Lu, Hua; Zeng, Chao

    2014-02-01

    Manipulating the energy flow of light is at the heart of modern information and communication technologies. Because photons are uncharged, it is still difficult to effectively control them by electrical means. Here, we propose a graphene plasmonic (GP) lens to efficiently manipulate energy flow by elaborately designing the thickness of the dielectric spacer beneath the graphene sheet. Different from traditional metal-based lenses, the proposed graphene plasmonic lens possesses the advantages of tunability and excellent confinement of surface plasmons. It is found that the proposed lens can be utilized to focus and collimate the GP waves propagating along the graphene sheet. Particularly, the lens is dispersionless over a wide frequency range and the performance of lens can be flexibly tuned by adjusting the bias voltage. As an application of such a lens, the image transfer of two point sources with a separation of λ0/30 is demonstrated.

  13. Graphene plasmonic lens for manipulating energy flow

    PubMed Central

    Wang, Guoxi; Liu, Xueming; Lu, Hua; Zeng, Chao

    2014-01-01

    Manipulating the energy flow of light is at the heart of modern information and communication technologies. Because photons are uncharged, it is still difficult to effectively control them by electrical means. Here, we propose a graphene plasmonic (GP) lens to efficiently manipulate energy flow by elaborately designing the thickness of the dielectric spacer beneath the graphene sheet. Different from traditional metal-based lenses, the proposed graphene plasmonic lens possesses the advantages of tunability and excellent confinement of surface plasmons. It is found that the proposed lens can be utilized to focus and collimate the GP waves propagating along the graphene sheet. Particularly, the lens is dispersionless over a wide frequency range and the performance of lens can be flexibly tuned by adjusting the bias voltage. As an application of such a lens, the image transfer of two point sources with a separation of λ0/30 is demonstrated. PMID:24517981

  14. A comparison of force sensing techniques for planetary manipulation

    NASA Technical Reports Server (NTRS)

    Helmick, Daniel; Okon, Avi; DiCicco, Matt

    2006-01-01

    Five techniques for sensing forces with a manipulator are compared analytically and experimentally. The techniques compared are: a six-axis wrist force/torque sensor, joint torque sensors, link strain gauges, motor current sensors, and flexibility modeling. The accuracy and repeatability fo each technique is quantified and compared.

  15. Manipulating Combinatorial Structures.

    ERIC Educational Resources Information Center

    Labelle, Gilbert

    This set of transparencies shows how the manipulation of combinatorial structures in the context of modern combinatorics can easily lead to interesting teaching and learning activities at every level of education from elementary school to university. The transparencies describe: (1) the importance and relations of combinatorics to science and…

  16. Manipulating the Gradient

    ERIC Educational Resources Information Center

    Gaze, Eric C.

    2005-01-01

    We introduce a cooperative learning, group lab for a Calculus III course to facilitate comprehension of the gradient vector and directional derivative concepts. The lab is a hands-on experience allowing students to manipulate a tangent plane and empirically measure the effect of partial derivatives on the direction of optimal ascent. (Contains 7…

  17. Trust versus Manipulation

    ERIC Educational Resources Information Center

    Lewis, Anne C.

    2005-01-01

    This article discusses the issue of trust in the education system. What is different about the issue of trust in the education system is the assault upon it, sometimes overt but most often subtle. There is a difference between strong criticism and willful manipulation. The nation's schools are responding to the former--perhaps too slowly for…

  18. Kinematically redundant robot manipulators

    NASA Technical Reports Server (NTRS)

    Baillieul, J.; Hollerbach, J.; Brockett, R.; Martin, D.; Percy, R.; Thomas, R.

    1987-01-01

    Research on control, design and programming of kinematically redundant robot manipulators (KRRM) is discussed. These are devices in which there are more joint space degrees of freedom than are required to achieve every position and orientation of the end-effector necessary for a given task in a given workspace. The technological developments described here deal with: kinematic programming techniques for automatically generating joint-space trajectories to execute prescribed tasks; control of redundant manipulators to optimize dynamic criteria (e.g., applications of forces and moments at the end-effector that optimally distribute the loading of actuators); and design of KRRMs to optimize functionality in congested work environments or to achieve other goals unattainable with non-redundant manipulators. Kinematic programming techniques are discussed, which show that some pseudo-inverse techniques that have been proposed for redundant manipulator control fail to achieve the goals of avoiding kinematic singularities and also generating closed joint-space paths corresponding to close paths of the end effector in the workspace. The extended Jacobian is proposed as an alternative to pseudo-inverse techniques.

  19. Computer Algebra versus Manipulation

    ERIC Educational Resources Information Center

    Zand, Hossein; Crowe, David

    2004-01-01

    In the UK there is increasing concern about the lack of skill in algebraic manipulation that is evident in students entering mathematics courses at university level. In this note we discuss how the computer can be used to ameliorate some of the problems. We take as an example the calculations needed in three dimensional vector analysis in polar…

  20. NASA Laboratory telerobotic manipulator control system architecture

    NASA Technical Reports Server (NTRS)

    Rowe, J. C.; Butler, P. L.; Glassell, R. L.; Herndon, J. N.

    1991-01-01

    In support of the National Aeronautics and Space Administration (NASA) goals to increase the utilization of dexterous robotic systems in space, the Oak Ridge National Laboratory (ORNL) has developed the Laboratory Telerobotic Manipulator (LTM) system. It is a dexterous, dual-arm, force reflecting teleoperator system with robotic features for NASA ground-based research. This paper describes the overall control system architecture, including both the hardware and software. The control system is a distributed, modular, and hierarchical design with flexible expansion capabilities for future enhancements of both the hardware and software.

  1. Dynamic Analysis of a Two Member Manipulator Arm

    NASA Technical Reports Server (NTRS)

    McGinley, Mark; Shen, Ji Y.

    1997-01-01

    Attenuating start-up and stopping vibrations when maneuvering large payloads attached to flexible manipulator systems is a great concern for many space missions. To address this concern, it was proposed that the use of smart materials, and their applications in smart structures, may provide an effective method of control for aerospace structures. In this paper, a modified finite element model has been developed to simulate the performance of piezoelectric ceramic actuators, and was applied to a flexible two-arm manipulator system. Connected to a control voltage, the piezoelectric actuators produce control moments based on the optimal control theory. The computer simulation modeled the end-effector vibration suppression of the NASA manipulator testbed for berthing operations of the Space Shuttle to the Space Station. The results of the simulation show that the bonded piezoelectric actuators can effectively suppress follow-up vibrations of the end-effector, stimulated by some external disturbance.

  2. Manipulators inspired by the tongue of the chameleon.

    PubMed

    Debray, Alexis

    2011-06-01

    Chameleons have developed a specialized ballistic tongue which elongates more than six times its rest length at speeds higher than 3.5 m s(-1) and accelerations 350 m s(-2), with a highly flexible mobile part, and which applies no continuous force during forward motion. These characteristics are possible because this tongue consists of two highly specialized systems, an ejection system for the forward motion and an accordion-like system for the retraction. Four manipulators inspired by the tongue of the chameleon and based on this design have been developed, resulting in three characteristics similar to the tongue of the chameleon: extensibility of the manipulator, flexibility of the mobile part, and absence of continuous force during the forward motion. The first manipulator mimics the basic mechanism of the tongue of the chameleon and reproduced its basic performances. A second manipulator performs a catching function at a speed of 3.5 m s(-1) with an acceleration of 573 m s(-2) while elongating seven times its rest length. The design of this manipulator is such that the dc motor used for retraction applies a torque 25 times its rated torque. Moreover, during the retraction, the mobile part of the manipulator moves due to its own inertia, allowing the dc motor to rotate at full velocity. In another manipulator, the addition of an elastomer in the mobile part allows for control of the retraction velocity. A model for these two manipulators compares well with the experimental data. Finally, the addition of wings on the mobile part allows us to take the advantage of aerodynamic effects, which is unusual for manipulators. PMID:21422504

  3. Door breaching robotic manipulator

    NASA Astrophysics Data System (ADS)

    Schoenfeld, Erik; Parrington, Lawrence; von Muehlen, Stephan

    2008-04-01

    As unmanned systems become more commonplace in military, police, and other security forces, they are tasked to perform missions that the original hardware was not designed for. Current military robots are built for rough outdoor conditions and have strong inflexible manipulators designed to handle a wide range of operations. However, these manipulators are not well suited for some essential indoor tasks, including opening doors. This is a complicated kinematic task that places prohibitively difficult control challenges on the robot and the operator. Honeybee and iRobot have designed a modular door-breaching manipulator that mechanically simplifies the demands upon operator and robot. The manipulator connects to the existing robotic arm of the iRobot PackBot EOD. The gripper is optimized for grasping a variety of door knobs, levers, and car-door handles. It works in conjunction with a compliant wrist and magnetic lock-out mechanism that allows the wrist to remain rigid until the gripper has a firm grasp of the handle and then bend with its rotation and the swing of the door. Once the door is unlatched, the operator simply drives the robot through the doorway while the wrist compensates for the complex, multiple degree-of-freedom motion of the door. Once in the doorway the operator releases the handle, the wrist pops back into place, and the robot is ready for the next door. The new manipulator dramatically improves a robot's ability to non-destructively breach doors and perform an inspection of a room's content, a capability that was previously out of reach of unmanned systems.

  4. 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.

  5. Interactive digital image manipulation system

    NASA Technical Reports Server (NTRS)

    Henze, J.; Dezur, R.

    1975-01-01

    The system is designed for manipulation, analysis, interpretation, and processing of a wide variety of image data. LANDSAT (ERTS) and other data in digital form can be input directly into the system. Photographic prints and transparencies are first converted to digital form with an on-line high-resolution microdensitometer. The system is implemented on a Hewlett-Packard 3000 computer with 128 K bytes of core memory and a 47.5 megabyte disk. It includes a true color display monitor, with processing memories, graphics overlays, and a movable cursor. Image data formats are flexible so that there is no restriction to a given set of remote sensors. Conversion between data types is available to provide a basis for comparison of the various data. Multispectral data is fully supported, and there is no restriction on the number of dimensions. In this way multispectral data collected at more than one point in time may simply be treated as a data collected with twice (three times, etc.) the number of sensors. There are various libraries of functions available to the user: processing functions, display functions, system functions, and earth resources applications functions.

  6. Computer aided manipulator control

    NASA Technical Reports Server (NTRS)

    Bejczy, A. K.; Zawacki, R. L.

    1980-01-01

    This paper describes the hardware and software system of a dedicated mini- and microcomputer network developed at the JPL teleoperator project to aid the operator in real-time control of remote manipulators. The operator can be in series or in parallel with the control computer during operation. The purpose of the project is to develop, demonstrate and evaluate advanced supervisory control concepts and techniques for space applications. The paper concludes with a brief outline of future development plans and issues.

  7. Manipulation of quantum evolution

    NASA Technical Reports Server (NTRS)

    Cabera, David Jose Fernandez; Mielnik, Bogdan

    1994-01-01

    The free evolution of a non-relativistic charged particle is manipulated using time-dependent magnetic fields. It is shown that the application of a programmed sequence of magnetic pulses can invert the free evolution process, forcing an arbitrary wave packet to 'go back in time' to recover its past shape. The possibility of more general operations upon the Schrodinger wave packet is discussed.

  8. Microradiographic microsphere manipulator

    DOEpatents

    Singleton, Russell M.

    1980-01-01

    A method and apparatus for radiographic characterization of small hollow spherical members (microspheres), constructed of either optically transparent or opaque materials. The apparatus involves a microsphere manipulator which holds a batch of microspheres between two parallel thin plastic films for contact microradiographic characterization or projection microradiography thereof. One plastic film is translated to relative to and parallel to the other to roll the microspheres through any desired angle to allow different views of the microspheres.

  9. Microradiographic microsphere manipulator

    DOEpatents

    Singleton, R.M.

    A method and apparatus is disclosed for radiographic characterization of small hollow spherical members (microspheres), constructed of either optically transparent or opaque materials. The apparatus involves a microsphere manipulator which holds a batch of microspheres between two parallel thin plastic films for contact microradiographic characterization or projection microradiography thereof. One plastic film is translated relative to and parallel to the other to roll the microspheres through any desired angle to allow different views of the microspheres.

  10. MANIPULATOR FOR SLAVE ROBOT

    DOEpatents

    Goertz, R.C.; Grimson, J.H.; Kohut, F.A.

    1961-04-01

    A remote-control manipulator comprising two stationary master units, two slave units on a movable vehicle, and electrical connections between the master and slave units is reported. The slave units are side by side with a minimum over-all width, which is made feasible by an arrangement of transducers producing most movements of each slave unit to one side of the support of said slave unit.

  11. Dynamic manipulation of particles via transformative optofluidic waveguides

    NASA Astrophysics Data System (ADS)

    Lee, Kang Soo; Lee, Kyung Heon; Kim, Sang Bok; Ha, Byung Hang; Jung, Jin Ho; Sung, Hyung Jin; Kim, Sang Soo

    2015-10-01

    Optofluidics is one of the most remarkable areas in the field of microfluidic research. Particle manipulation with optofluidic platforms has become central to optical chromatography, biotechnology, and μ-total analysis systems. Optical manipulation of particles depends on their sizes and refractive indices (n), which occasionally leads to undesirable separation consequences when their optical mobilities are identical. Here, we demonstrate rapid and dynamic particle manipulation according to n, regardless of size. Integrated liquid-core/solid-cladding (LS) and liquid-core/liquid-cladding (L2) waveguides were fabricated and their characteristics were experimentally and theoretically determined. The high and low n particles showed the opposite behaviors by controlling the contrast of their n values to those of the working fluids. The LS waveguide was found to successfully manipulate particles according to n, and the L2 waveguide was found to provide additional system stability and flexibility, compared to the LS system.

  12. Dynamic manipulation of particles via transformative optofluidic waveguides

    PubMed Central

    Lee, Kang Soo; Lee, Kyung Heon; Kim, Sang Bok; Ha, Byung Hang; Jung, Jin Ho; Sung, Hyung Jin; Kim, Sang Soo

    2015-01-01

    Optofluidics is one of the most remarkable areas in the field of microfluidic research. Particle manipulation with optofluidic platforms has become central to optical chromatography, biotechnology, and μ-total analysis systems. Optical manipulation of particles depends on their sizes and refractive indices (n), which occasionally leads to undesirable separation consequences when their optical mobilities are identical. Here, we demonstrate rapid and dynamic particle manipulation according to n, regardless of size. Integrated liquid-core/solid-cladding (LS) and liquid-core/liquid-cladding (L2) waveguides were fabricated and their characteristics were experimentally and theoretically determined. The high and low n particles showed the opposite behaviors by controlling the contrast of their n values to those of the working fluids. The LS waveguide was found to successfully manipulate particles according to n, and the L2 waveguide was found to provide additional system stability and flexibility, compared to the LS system. PMID:26471003

  13. An integrated open-cavity system for magnetic bead manipulation.

    PubMed

    Abu-Nimeh, F T; Salem, F M

    2013-02-01

    Superparamagnetic beads are increasingly used in biomedical assays to manipulate, transport, and maneuver biomaterials. We present a low-cost integrated system designed in bulk CMOS to manipulate and separate biomedical magnetic beads. The system consists of 8 × 8 coil-arrays suitable for single bead manipulation, or collaborative multi-bead manipulation, using pseudo-parallel executions. We demonstrate the flexibility of the design in terms of different coil sizes, DC current levels, and layout techniques. In one array module example, the size of a single coil is 30 μm × 30 μm and the full array occupies an area of 248 μm × 248 μm in 0.5 μm CMOS technology. The programmable DC current source supports 8 discrete levels up to 1.5 mA. The total power consumption of the entire module is 9 mW when running at full power. PMID:23853277

  14. Endocavity Ultrasound Probe Manipulators.

    PubMed

    Stoianovici, Dan; Kim, Chunwoo; Schäfer, Felix; Huang, Chien-Ming; Zuo, Yihe; Petrisor, Doru; Han, Misop

    2013-06-01

    We developed two similar structure manipulators for medical endocavity ultrasound probes with 3 and 4 degrees of freedom (DoF). These robots allow scanning with ultrasound for 3-D imaging and enable robot-assisted image-guided procedures. Both robots use remote center of motion kinematics, characteristic of medical robots. The 4-DoF robot provides unrestricted manipulation of the endocavity probe. With the 3-DoF robot the insertion motion of the probe must be adjusted manually, but the device is simpler and may also be used to manipulate external-body probes. The robots enabled a novel surgical approach of using intraoperative image-based navigation during robot-assisted laparoscopic prostatectomy (RALP), performed with concurrent use of two robotic systems (Tandem, T-RALP). Thus far, a clinical trial for evaluation of safety and feasibility has been performed successfully on 46 patients. This paper describes the architecture and design of the robots, the two prototypes, control features related to safety, preclinical experiments, and the T-RALP procedure. PMID:24795525

  15. Welding nozzle position manipulator

    NASA Technical Reports Server (NTRS)

    Gilbert, Jeffrey L. (Inventor); Gutow, David A. (Inventor)

    1994-01-01

    The present invention is directed to a welding nozzle position manipulator. The manipulator consists of an angle support to which the remaining components of the device are attached either directly or indirectly. A pair of pivotal connections attach a weld nozzle holding link to the angle support and provide a two axis freedom of movement of the holding link with respect to the support angle. The manipulator is actuated by a pair of adjusting screws angularly mounted to the angle support. These screws contact a pair of tapered friction surfaces formed on the upper portion of the welding nozzle holding link. A spring positioned between the upper portions of the support angle and the holding link provides a constant bias engagement between the friction surfaces of the holding link and the adjustment screws, so as to firmly hold the link in position and to eliminate any free play in the adjustment mechanism. The angular relationships between the adjustment screws, the angle support and the tapered friction surfaces of the weld nozzle holding link provide a geometric arrangement which permits precision adjustment of the holding link with respect to the angle support and also provides a solid holding link mount which is resistant to movement from outside forces.

  16. Endocavity Ultrasound Probe Manipulators

    PubMed Central

    Stoianovici, Dan; Kim, Chunwoo; Schäfer, Felix; Huang, Chien-Ming; Zuo, Yihe; Petrisor, Doru; Han, Misop

    2014-01-01

    We developed two similar structure manipulators for medical endocavity ultrasound probes with 3 and 4 degrees of freedom (DoF). These robots allow scanning with ultrasound for 3-D imaging and enable robot-assisted image-guided procedures. Both robots use remote center of motion kinematics, characteristic of medical robots. The 4-DoF robot provides unrestricted manipulation of the endocavity probe. With the 3-DoF robot the insertion motion of the probe must be adjusted manually, but the device is simpler and may also be used to manipulate external-body probes. The robots enabled a novel surgical approach of using intraoperative image-based navigation during robot-assisted laparoscopic prostatectomy (RALP), performed with concurrent use of two robotic systems (Tandem, T-RALP). Thus far, a clinical trial for evaluation of safety and feasibility has been performed successfully on 46 patients. This paper describes the architecture and design of the robots, the two prototypes, control features related to safety, preclinical experiments, and the T-RALP procedure. PMID:24795525

  17. Investigation of Boundary Conditions for Flexible Multibody Spacecraft Dynamics

    NASA Technical Reports Server (NTRS)

    MacLean, John R.; Huynh, An; Quiocho, Leslie J.

    2007-01-01

    In support of both the Space Shuttle and International Space Station programs, a set of generic multibody dynamics algorithms integrated within the Trick simulation environment have addressed the variety of on-orbit manipulator simulation requirements for engineering analysis, procedures development and crew familiarization/training at the NASA Johnson Space Center (JSC). Enhancements to these dynamics algorithms are now being driven by a new set of Constellation program requirements for flexible multibody spacecraft simulation. One particular issue that has been discussed within the NASA community is the assumption of cantilever-type flexible body boundary conditions. This assumption has been commonly utilized within manipulator multibody dynamics formulations as it simplifies the computation of relative motion for articulated flexible topologies. Moreover, its use for modeling of space-based manipulators such as the Shuttle Remote Manipulator System (SRMS) and Space Station Remote Manipulator System (SSRMS) has been extensively validated against flight data. For more general flexible spacecraft applications, however, the assumption of cantilever-type boundary conditions may not be sufficient. This paper describes the boundary condition assumptions that were used in the original formulation, demonstrates that this formulation can be augmented to accommodate systems in which the assumption of cantilever boundary conditions no longer applies, and verifies the approach through comparison with an independent model previously validated against experimental hardware test data from a spacecraft flexible dynamics emulator.

  18. Tip velocity tracking control for elastic manipulators

    NASA Astrophysics Data System (ADS)

    Sever, Manfred Dieter Martin

    A unique approach to tip velocity control of an elastic robotic manipulator is presented. This method has potential application in teleoperation control and in applications where the trajectory is generated in real-time. Control is effected by reducing the tip velocity tracking error between the desired tip velocity and the measured tip velocity. Thus, in teleoperation, the concept of dead reckoning is used, so that while the manipulator's desired tip velocity is specified, the goal is for the tip to follow a path, leading toward a desired terminal position. This is done by concentrating the controller's effort on the manipulator tip while allowing the manipulator's links to deform., The controller utilizes a gain scheduling scheme to arrive at an appropriate feedback law. The control algorithm is implemented using a parallel-processing scheme on a multiprocessor system which consists of INMOS TransputersRTM . Experimental results are obtained using Radius, the Space Robotics Laboratory Facility at the University of Toronto Institute for Aerospace Studies. Radius was designed to serve specifically as a test-bed for the development and evaluation of control methods for elastic manipulators. For the present work Radius is configured as a two-link manipulator with both links structurally flexible. One of the trajectories used for the simulations and experiment is a square, which is quite difficult for an elastic manipulator to execute. This box trajectory is more demanding than trajectories typically executed by Canadarm and so link elasticity becomes an important consideration. The effect of elasticity is demonstrated using an independent joint PD controller. In simulation, excellent tip velocity tracking was achieved using the proposed controller. In the experiment, reasonable accuracy in following the desired tip path was attained, however, disturbances, mainly a result of unmodeled joint dynamics, caused degraded performance. The controller may be improved by

  19. Direct Manipulation and Procedural Reasoning.

    ERIC Educational Resources Information Center

    Owen, David

    Arguing that understanding what lies behind the apparent usability of direct manipulation style interfaces might not only help in building better interfaces, but can also draw attention to possible side effects, this paper uses examples from a prototype data manipulation system to pursue a characterization of direct manipulation interfaces as…

  20. Light manipulation with encoded plasmonic nanostructures

    NASA Astrophysics Data System (ADS)

    Zhao, Chenglong; Zhang, Jiasen; Liu, Yongmin

    2014-12-01

    Plasmonics, which allows for manipulation of light field beyond the fundamental diffraction limit, has recently attracted tremendous research efforts. The propagating surface plasmon polaritons (SPPs) confined on a metal-dielectric interface provide an ideal two-dimensional (2D) platform to develop subwavelength optical circuits for on-chip information processing and communication. The surface plasmon resonance of rationally designed metallic nanostructures, on the other hand, enables pronounced phase and polarization modulation for light beams travelling in three-dimensional (3D) free space. Flexible 2D and free-space propagating light manipulation can be achieved by encoding plasmonic nanostructures on a 2D surface, promising the design, fabrication and integration of the next-generation optical architectures with substantially reduced footprint. It is envisioned that the encoded plasmonic nanostructures can significantly expand available toolboxes for novel light manipulation. In this review, we presents the fundamentals, recent developments and future perspectives in this emerging field, aiming to open up new avenues to developing revolutionary photonic devices.

  1. Flexible packaging and integration of CMOS IC with elastomeric microfluidics

    NASA Astrophysics Data System (ADS)

    Zhang, Bowei; Dong, Quan; Korman, Can E.; Li, Zhenyu; Zaghloul, Mona E.

    2013-05-01

    We have demonstrated flexible packaging and integration of CMOS IC chips with PDMS microfluidics. Microfluidic channels are used to deliver both liquid samples and liquid metals to the CMOS die. The liquid metals are used to realize electrical interconnects to the CMOS chip. As a demonstration we integrated a CMOS magnetic sensor die and matched PDMS microfluidic channels in a flexible package. The packaged system is fully functional under 3cm bending radius. The flexible integration of CMOS ICs with microfluidics enables previously unavailable flexible CMOS electronic systems with fluidic manipulation capabilities, which hold great potential for wearable health monitoring, point-of-care diagnostics and environmental sensing.

  2. Manipulation of thermal phonons

    NASA Astrophysics Data System (ADS)

    Hsu, Chung-Hao

    Developing materials that can conduct electricity easily, but block the motion of phonons is necessary in the applications of thermoelectric devices, which can generate electricity from temperature differences. In converse, a key requirement as chips get faster is to obtain better ways to dissipate heat. Controlling heat transfer in these crystalline materials devices --- such as silicon --- is important. The heat is actually the motion or vibration of atoms known as phonons. Finding ways to manipulate the behavior of phonons is crucial for both energy applications and the cooling of integrated circuits. A novel class of artificially periodic structured materials --- phononic crystals --- might make manipulation of thermal phonons possible. In many fields of physical sciences and engineering, acoustic wave propagation in solids attracts many researchers. Wave propagation phenomena can be analyzed by mathematically solving the acoustic wave equation. However, wave propagation in inhomogeneous media with various geometric structures is too complex to find an exact solution. Hence, the Finite Difference Time Domain method is developed to investigate these complicated problems. In this work, the Finite-Difference Time-Domain formula is derived from acoustic wave equations based on the Taylor's expansion. The numerical dispersion and stability problems are analyzed. In addition, the convergence conditions of numerical acoustic wave are stated. Based on the periodicity of phononic crystal, the Bloch's theorem is applied to fulfill the periodic boundary condition of the FDTD method. Then a wide-band input signal is used to excite various acoustic waves with different frequencies. In the beginning of the calculation process, the wave vector is chosen and fixed. By means of recording the displacement field and taking the Fourier transformation, we can obtain the eigenmodes from the resonance peaks of the spectrum and draw the dispersion relation curve of acoustic waves

  3. Spatial Manipulation with Microfluidics

    PubMed Central

    Lin, Benjamin; Levchenko, Andre

    2015-01-01

    Biochemical gradients convey information through space, time, and concentration, and are ultimately capable of spatially resolving distinct cellular phenotypes, such as differentiation, proliferation, and migration. How these gradients develop, evolve, and function during development, homeostasis, and various disease states is a subject of intense interest across a variety of disciplines. Microfluidic technologies have become essential tools for investigating gradient sensing in vitro due to their ability to precisely manipulate fluids on demand in well-controlled environments at cellular length scales. This review will highlight their utility for studying gradient sensing along with relevant applications to biology. PMID:25905100

  4. Spatial manipulation with microfluidics.

    PubMed

    Lin, Benjamin; Levchenko, Andre

    2015-01-01

    Biochemical gradients convey information through space, time, and concentration, and are ultimately capable of spatially resolving distinct cellular phenotypes, such as differentiation, proliferation, and migration. How these gradients develop, evolve, and function during development, homeostasis, and various disease states is a subject of intense interest across a variety of disciplines. Microfluidic technologies have become essential tools for investigating gradient sensing in vitro due to their ability to precisely manipulate fluids on demand in well-controlled environments at cellular length scales. This review will highlight their utility for studying gradient sensing along with relevant applications to biology. PMID:25905100

  5. Performance measurement of mobile manipulators

    NASA Astrophysics Data System (ADS)

    Bostelman, Roger; Hong, Tsai; Marvel, Jeremy

    2015-05-01

    This paper describes a concept for measuring the reproducible performance of mobile manipulators to be used for assembly or other similar tasks. An automatic guided vehicle with an onboard robot arm was programmed to repeatedly move to and stop at a novel, reconfigurable mobile manipulator artifact (RMMA), sense the RMMA, and detect targets on the RMMA. The manipulator moved a laser retroreflective sensor to detect small reflectors that can be reconfigured to measure various manipulator positions and orientations (poses). This paper describes calibration of a multi-camera, motion capture system using a 6 degree-of-freedom metrology bar and then using the camera system as a ground truth measurement device for validation of the reproducible mobile manipulator's experiments and test method. Static performance measurement of a mobile manipulator using the RMMA has proved useful for relatively high tolerance pose estimation and other metrics that support standard test method development for indexed and dynamic mobile manipulator applications.

  6. Computational Control of Flexible Aerospace Systems

    NASA Technical Reports Server (NTRS)

    Sharpe, Lonnie, Jr.; Shen, Ji Yao

    1994-01-01

    The main objective of this project is to establish a distributed parameter modeling technique for structural analysis, parameter estimation, vibration suppression and control synthesis of large flexible aerospace structures. This report concentrates on the research outputs produced in the last two years of the project. The main accomplishments can be summarized as follows. A new version of the PDEMOD Code had been completed. A theoretical investigation of the NASA MSFC two-dimensional ground-based manipulator facility by using distributed parameter modelling technique has been conducted. A new mathematical treatment for dynamic analysis and control of large flexible manipulator systems has been conceived, which may provide a embryonic form of a more sophisticated mathematical model for future modified versions of the PDEMOD Codes.

  7. Parasites and supernormal manipulation.

    PubMed

    Holen, Ø H; Saetre, G P; Slagsvold, T; Stenseth, N C

    2001-12-22

    Social parasites may exploit their hosts by mimicking other organisms that the hosts normally benefit from investing in or responding to in some other way. Some parasites exaggerate key characters of the organisms they mimic, possibly in order to increase the response from the hosts. The huge gape and extreme begging intensity of the parasitic common cuckoo chick (Cuculus canorus) may be an example. In this paper, the evolutionary stability of manipulating hosts through exaggerated signals is analysed using game theory. Our model indicates that a parasite's signal intensity must be below a certain threshold in order to ensure acceptance and that this threshold depends directly on the rate of parasitism. The only evolutionarily stable strategy (ESS) combination is when hosts accept all signallers and parasites signal at their optimal signal intensity, which must be below the threshold. Supernormal manipulation by parasites is only evolutionarily stable under sufficiently low rates of parasitism. If the conditions for the ESS combination are not satisfied, rejector hosts can invade using signal intensity as a cue for identifying parasites. These qualitative predictions are discussed with respect to empirical evidence from parasitic mimicry systems that have been suggested to involve supernormal signalling, including evicting avian brood parasites and insect-mimicking Ophrys orchids. PMID:11749709

  8. Multiplexed Force and Deflection Sensing Shell Membranes for Robotic Manipulators

    NASA Technical Reports Server (NTRS)

    Park, Yong-Lae; Black, Richard; Moslehi, Behzad; Cutkosky, Mark; Chau, Kelvin

    2012-01-01

    Force sensing is an essential requirement for dexterous robot manipulation, e.g., for extravehicular robots making vehicle repairs. Although strain gauges have been widely used, a new sensing approach is desirable for applications that require greater robustness, design flexibility including a high degree of multiplexibility, and immunity to electromagnetic noise. This invention is a force and deflection sensor a flexible shell formed with an elastomer having passageways formed by apertures in the shell, with an optical fiber having one or more Bragg gratings positioned in the passageways for the measurement of force and deflection.

  9. Interactive protein manipulation

    SciTech Connect

    SNCrivelli@lbl.gov

    2003-07-01

    We describe an interactive visualization and modeling program for the creation of protein structures ''from scratch''. The input to our program is an amino acid sequence -decoded from a gene- and a sequence of predicted secondary structure types for each amino acid-provided by external structure prediction programs. Our program can be used in the set-up phase of a protein structure prediction process; the structures created with it serve as input for a subsequent global internal energy minimization, or another method of protein structure prediction. Our program supports basic visualization methods for protein structures, interactive manipulation based on inverse kinematics, and visualization guides to aid a user in creating ''good'' initial structures.

  10. Vacuum tool manipulator

    DOEpatents

    Zollinger, William T.

    1993-01-01

    Apparatus for manipulating a vacuum hose in a reactor vessel comprises a housing with two opposing openings, an arm carried by the housing and deployable from a stowed position essentially completely within the housing to an extended position where the arm extends through the two openings in a generally horizontal position. The arm preferably has a two-fingered gripping device for gripping the vacuum hose but may carry a different end effector such as a grinding wheel. The fingers are opened and closed by one air cylinder. A second air cylinder extends the device. A third air cylinder within the housing pivotally pulls the opposing end of the arm into the housing via a pivoting member pivotally connected between the third air cylinder shaft and the arm.

  11. Simple, efficient UHV manipulator

    SciTech Connect

    Thiel, P.A.; Anderegg, J.W.

    1984-10-01

    A simple manipulator is described for use in ultrahigh vacuum. Unhindered rotation within vacuum is provided by a commercial differentially pumped adapter to which the entire XYZ stage is attached. The combination of movements provided by the XYZ stage, the rotating vacuum flange, and a gimbal permits alignment of the sample with any of the peripheral view ports. The resistively heated sample support, mounted through a cold finger, permits rapid variation of sample temperature from several hundred degrees Kelvin to near cryogenic. It is anticipated that this design could be easily used with many existing types of commercial vacuum systems, with the consequent advantage of increased ease and simplicity of both mechanical motion and cryogenic cooling.

  12. Ion manipulation device

    DOEpatents

    Anderson, Gordon A; Smith, Richard D; Ibrahim, Yehia M; Baker, Erin M

    2014-09-16

    An ion manipulation method and device is disclosed. The device includes a pair of substantially parallel surfaces. An array of inner electrodes is contained within, and extends substantially along the length of, each parallel surface. The device includes a first outer array of electrodes and a second outer array of electrodes. Each outer array of electrodes is positioned on either side of the inner electrodes, and is contained within and extends substantially along the length of each parallel surface. A DC voltage is applied to the first and second outer array of electrodes. A RF voltage, with a superimposed electric field, is applied to the inner electrodes by applying the DC voltages to each electrode. Ions either move between the parallel surfaces within an ion confinement area or along paths in the direction of the electric field, or can be trapped in the ion confinement area.

  13. Advanced servo manipulator

    DOEpatents

    Holt, W.E.; Kuban, D.P.; Martin, H.L.

    1988-10-25

    An advanced servo manipulator has modular parts. Modular motor members drive individual input gears to control shoulder roll, shoulder pitch, elbow pitch, wrist yaw, wrist pitch, wrist roll, and tong spacing. The modules include a support member, a shoulder module for controlling shoulder roll, and a sleeve module attached to the shoulder module in fixed relation thereto. The shoulder roll sleeve module has an inner cylindrical member rotatable relative to the outer cylindrical member, and upon which a gear pod assembly is mounted. A plurality of shafts are driven by the gears, which are in turn driven by individual motor modules to transmit rotary power to control elbow pitch as well as to provide four different rotary shafts across the bendable elbow joint to supply rotary motive power to a wrist member and tong member. 41 figs.

  14. Advanced servo manipulator

    DOEpatents

    Holt, William E.; Kuban, Daniel P.; Martin, H. Lee

    1988-01-01

    An advanced servo manipulator has modular parts. Modular motor members drive individual input gears to control shoulder roll, shoulder pitch, elbow pitch, wrist yaw, wrist pitch, wrist roll, and tong spacing. The modules include a support member, a shoulder module for controlling shoulder roll, and a sleeve module attached to the shoulder module in fixed relation thereto. The shoulder roll sleeve module has an inner cylindrical member rotatable relative to the outer cylindrical member, and upon which a gear pod assembly is mounted. A plurality of shafts are driven by the gears, which are in turn driven by individual motor modules to transmit rotary power to control elbow pitch as well as to provide four different rotary shafts across the bendable elbow joint to supply rotary motive power to a wrist member and tong member.

  15. Vacuum tool manipulator

    DOEpatents

    Zollinger, W.T.

    1993-11-23

    Apparatus for manipulating a vacuum hose in a reactor vessel comprises a housing with two opposing openings, an arm carried by the housing and deployable from a stowed position essentially completely within the housing to an extended position where the arm extends through the two openings in a generally horizontal position. The arm preferably has a two-fingered gripping device for gripping the vacuum hose but may carry a different end effector such as a grinding wheel. The fingers are opened and closed by one air cylinder. A second air cylinder extends the device. A third air cylinder within the housing pivotally pulls the opposing end of the arm into the housing via a pivoting member pivotally connected between the third air cylinder shaft and the arm. 6 figures.

  16. Adaptive control of robotic manipulators

    NASA Technical Reports Server (NTRS)

    Seraji, H.

    1987-01-01

    The author presents a novel approach to adaptive control of manipulators to achieve trajectory tracking by the joint angles. The central concept in this approach is the utilization of the manipulator inverse as a feedforward controller. The desired trajectory is applied as an input to the feedforward controller which behaves as the inverse of the manipulator at any operating point; the controller output is used as the driving torque for the manipulator. The controller gains are then updated by an adaptation algorithm derived from MRAC (model reference adaptive control) theory to cope with variations in the manipulator inverse due to changes of the operating point. An adaptive feedback controller and an auxiliary signal are also used to enhance closed-loop stability and to achieve faster adaptation. The proposed control scheme is computationally fast and does not require a priori knowledge of the complex dynamic model or the parameter values of the manipulator or the payload.

  17. A History of Manipulative Therapy

    PubMed Central

    Pettman, Erland

    2007-01-01

    Manipulative therapy has known a parallel development throughout many parts of the world. The earliest historical reference to the practice of manipulative therapy in Europe dates back to 400 BCE. Over the centuries, manipulative interventions have fallen in and out of favor with the medical profession. Manipulative therapy also was initially the mainstay of the two leading alternative health care systems, osteopathy and chiropractic, both founded in the latter part of the 19th century in response to shortcomings in allopathic medicine. With medical and osteopathic physicians initially instrumental in introducing manipulative therapy to the profession of physical therapy, physical therapists have since then provided strong contributions to the field, thereby solidifying the profession's claim to have manipulative therapy within in its legally regulated scope of practice. PMID:19066664

  18. Spatial operator approach to flexible multibody system dynamics and control

    NASA Technical Reports Server (NTRS)

    Rodriguez, G.

    1991-01-01

    The inverse and forward dynamics problems for flexible multibody systems were solved using the techniques of spatially recursive Kalman filtering and smoothing. These algorithms are easily developed using a set of identities associated with mass matrix factorization and inversion. These identities are easily derived using the spatial operator algebra developed by the author. Current work is aimed at computational experiments with the described algorithms and at modelling for control design of limber manipulator systems. It is also aimed at handling and manipulation of flexible objects.

  19. Torque-Limiting Manipulation Device

    NASA Technical Reports Server (NTRS)

    Moetteli, John B. (Inventor)

    1999-01-01

    A device for manipulating a workpiece in space includes a fixture, a stanchion assembly, a manipulation mechanism, an actuation mechanism, and a reaction mechanism. The fixture has an end onto which the workpiece affixes. The stanchion assembly has an upper and a lower end. The manipulation mechanism connects the fixture and the upper end of the stanchion assembly. The lower end of the stanchion assembly mounts, via probe and a socket, to a structure. The actuation mechanism operably connects to the manipulation mechanism, and moves the fixture in space. The reaction mechanism provides a point through which force inputs into the actuation mechanism may react.

  20. Flexible robot control: Modeling and experiments

    NASA Technical Reports Server (NTRS)

    Oppenheim, Irving J.; Shimoyama, Isao

    1989-01-01

    Described here is a model and its use in experimental studies of flexible manipulators. The analytical model uses the equivalent of Rayleigh's method to approximate the displaced shape of a flexible link as the static elastic displacement which would occur under end rotations as applied at the joints. The generalized coordinates are thereby expressly compatible with joint motions and rotations in serial link manipulators, because the amplitude variables are simply the end rotations between the flexible link and the chord connecting the end points. The equations for the system dynamics are quite simple and can readily be formulated for the multi-link, three-dimensional case. When the flexible links possess mass and (polar moment of) inertia which are small compared to the concentrated mass and inertia at the joints, the analytical model is exact and displays the additional advantage of reduction in system dimension for the governing equations. Four series of pilot tests have been completed. Studies on a planar single-link system were conducted at Carnegie-Mellon University, and tests conducted at Toshiba Corporation on a planar two-link system were then incorporated into the study. A single link system under three-dimensional motion, displaying biaxial flexure, was then tested at Carnegie-Mellon.

  1. Manipulating and Visualizing Proteins

    SciTech Connect

    Simon, Horst D.

    2003-12-05

    ProteinShop Gives Researchers a Hands-On Tool for Manipulating, Visualizing Protein Structures. The Human Genome Project and other biological research efforts are creating an avalanche of new data about the chemical makeup and genetic codes of living organisms. But in order to make sense of this raw data, researchers need software tools which let them explore and model data in a more intuitive fashion. With this in mind, researchers at Lawrence Berkeley National Laboratory and the University of California, Davis, have developed ProteinShop, a visualization and modeling program which allows researchers to manipulate protein structures with pinpoint control, guided in large part by their own biological and experimental instincts. Biologists have spent the last half century trying to unravel the ''protein folding problem,'' which refers to the way chains of amino acids physically fold themselves into three-dimensional proteins. This final shape, which resembles a crumpled ribbon or piece of origami, is what determines how the protein functions and translates genetic information. Understanding and modeling this geometrically complex formation is no easy matter. ProteinShop takes a given sequence of amino acids and uses visualization guides to help generate predictions about the secondary structures, identifying alpha helices and flat beta strands, and the coil regions that bind them. Once secondary structures are in place, researchers can twist and turn these pre-configurations until they come up with a number of possible tertiary structure conformations. In turn, these are fed into a computationally intensive optimization procedure that tries to find the final, three-dimensional protein structure. Most importantly, ProteinShop allows users to add human knowledge and intuition to the protein structure prediction process, thus bypassing bad configurations that would otherwise be fruitless for optimization. This saves compute cycles and accelerates the entire process, so

  2. Precision manipulator heating and cooling assembly compatible with sample transfer

    NASA Technical Reports Server (NTRS)

    Outlaw, R. A.; Baugh, B. T.

    1982-01-01

    A technique is described for the transfer of a UHV sample system to a precision manipulator. It allows direct sample temperature measurement in a broad range of sample temperatures (150-1750 K) and simultaneously retains the benefit of the additional degree of freedom provided by the precision manipulator flip mechanism. The technique is similar to that reported by Crider (1976) but with several modifications. The pump is mounted at the extreme end of the magnetically coupled linear motion feedthrough (to maximize the separation). Samples are mounted on a threaded circular sample holder, transferred to the flip mechanism of the manipulator. The flip mechanism contains a rear electrode assembly and thermocouple, in direct contact with the sample, and a copper plate and a flexible strap are attached to the receiving block (to facilitate sample cooling).

  3. Computerized symbolic manipulation in nonlinear finite element analysis

    NASA Technical Reports Server (NTRS)

    Noor, A. K.; Andersen, C. M.

    1981-01-01

    The potential of using computerized symbolic manipulation in the development of nonlinear finite elements is discussed. Three tasks which can be efficiently performed using computerized symbolic manipulation are identified: (1) generation of algebraic expressions for the stiffness coefficients of nonlinear finite elements, (2) generation of FORTRAN source code for numerical evaluation of stiffness coefficients, and (3) checking the correctness of the FORTRAN statements for the arrays of coefficients. The symbolic and algebraic manipulation system MACSYMA is used in the present study. Two sample MACSYMA programs are presented for the development of the nonlinear stiffness coefficients of two-dimensional, shear-flexible, doubly-curved deep shell elements. The first program is for displacement models and the second program is for mixed models with discontinuous stress-resultant fields at interelement boundaries.

  4. Control of free-flying space robot manipulator systems

    NASA Technical Reports Server (NTRS)

    Cannon, Robert H., Jr.

    1990-01-01

    New control techniques for self contained, autonomous free flying space robots were developed and tested experimentally. Free flying robots are envisioned as a key element of any successful long term presence in space. These robots must be capable of performing the assembly, maintenance, and inspection, and repair tasks that currently require human extravehicular activity (EVA). A set of research projects were developed and carried out using lab models of satellite robots and a flexible manipulator. The second generation space robot models use air cushion vehicle (ACV) technology to simulate in 2-D the drag free, zero g conditions of space. The current work is divided into 5 major projects: Global Navigation and Control of a Free Floating Robot, Cooperative Manipulation from a Free Flying Robot, Multiple Robot Cooperation, Thrusterless Robotic Locomotion, and Dynamic Payload Manipulation. These projects are examined in detail.

  5. Simulation of man-machine interaction on shuttle payload manipulator

    NASA Technical Reports Server (NTRS)

    Hookway, R. O.; Jackson, R. S.

    1975-01-01

    The main objective of this simulation was to evaluate the feasibility of a simplified control system for a remote manipulator for space shuttle payloads. The motion commanded by the operator through the control system to the six degree of freedom manipulator approximates that of a backhoe. Compatibility of low arm damping, heavy payloads, small clearances in the shuttle cargo bay and stringent mission timelines were evaluated. The effects of various devices to enhance visual cues were evaluated. Phase I of the simulation was capture of a payload flying free in space relative to the shuttle. Phase II was simulation of cargo stowage into a mockup of the space shuttle cargo bay. A shuttle remote manipulator control station mockup including TV monitors and hand controllers is used in the simulation. Results evaluating various parameters of the control system and the task, including arm flexibility, are presented.

  6. Research on a Reconfigurable Modular Manipulator System. Final report, June 15, 1989--August 14, 1992

    SciTech Connect

    Khosla, P.K.; Kanade, T.

    1992-08-01

    Research has been conducted on developing the theoretical basis and the technology for a Reconfigurable Modular Manipulation System (RMMS). Unlike a conventional manipulator which has a fixed configuration, the RMMS consists of a set of interchangeable modules that can be rapidly assembled into a system of manipulators with appropriate configurations depending on the specific task requirement. For effective development and use of such a versatile and flexible system a program of theoretical and experimental research has been pursued aimed at developing the basis for next generation of autonomous manipulator systems. The RMMS concept extends the idea of autonomy from sensor-based to configuration based autonomy. One of the important components is the development of design methodologies for mapping tasks into manipulator configurations and for automatic generation of manipulator specific algorithms (e.g., kinematics and dynamics) in order to make the hardware transparent to the user.(JDB)

  7. Flexibility and Muscular Strength.

    ERIC Educational Resources Information Center

    Liemohn, Wendell

    1988-01-01

    This definition of flexibility and muscular strength also explores their roles in overall physical fitness and focuses on how increased flexibility and muscular strength can help decrease or eliminate lower back pain. (CB)

  8. Manipulating Liquids With Acoustic Radiation Pressure Phased Arrays

    NASA Technical Reports Server (NTRS)

    Oeftering, Richard C.

    1999-01-01

    High-intensity ultrasound waves can produce the effects of "Acoustic Radiation Pressure" (ARP) and "acoustic streaming." These effects can be used to propel liquid flows and to apply forces that can be used to move or manipulate floating objects or liquid surfaces. NASA's interest in ARP includes the remote-control agitation of liquids and the manipulation of bubbles and drops in liquid experiments and propellant systems. A high level of flexibility is attained by using a high-power acoustic phased array to generate, steer, and focus a beam of acoustic waves. This is called an Acoustic Radiation Pressure Phased Array, or ARPPA. In this approach, many acoustic transducer elements emit wavelets that converge into a single beam of sound waves. Electronically coordinating the timing, or "phase shift," of the acoustic waves makes it possible to form a beam with a predefined direction and focus. Therefore, a user can direct the ARP force at almost any desired point within a liquid volume. ARPPA lets experimenters manipulate objects anywhere in a test volume. This flexibility allow it to be used for multiple purposes, such as to agitate liquids, deploy and manipulate drops or bubbles, and even suppress sloshing in spacecraft propellant tanks.

  9. Image Manipulation: Then and Now.

    ERIC Educational Resources Information Center

    Sutton, Ronald E.

    The images of photography have been manipulated almost from the moment of their discovery. The blending together in the studio and darkroom of images not found in actual scenes from life has been a regular feature of modern photography in both art and advertising. Techniques of photograph manipulation include retouching; blocking out figures or…

  10. Modeling Manipulation in Medical Education

    ERIC Educational Resources Information Center

    Dailey, Jason I.

    2010-01-01

    As residents and medical students progress through their medical training, they are presented with multiple instances in which they feel they must manipulate the healthcare system and deceive others in order to efficiently treat their patients. This, however, creates a culture of manipulation resulting in untoward effects on trainees' ethical and…

  11. Improvements to the Tendon-Actuated Lightweight In-Space MANipulator (TALISMAN)

    NASA Technical Reports Server (NTRS)

    Doggett, William R.; Dorsey, John T.; Jones, Thomas C.; Lodding, Kenneth N.; Ganoe, George G.; Mercer, David; King, Bruce D.

    2015-01-01

    Devices for manipulating and precisely placing payloads are critical for efficient space operations including berthing of spacecraft, in-space assembly, construction and repair. Key to the success of many NASA space activities has been the availability of long-reach crane-like devices such as the Shuttle Remote Manipulation System (SRMS) and the Space Station Remote Manipulation System (SSRMS). These devices have been used for many operations including berthing visiting spacecraft to the International Space Station, deployment of spacecraft, space station assembly, astronaut positioning, payload transfer, and spacecraft inspection prior to atmospheric re-entry. Retiring the Space Transportation System has led to the removal of the SRMS from consideration for in-space missions, thus creating a capability gap. Recognizing this gap, work was initiated at NASA on a new architecture for long-reach space manipulators. Most current devices are constructed by joining revolute joints with carbon composite tubes, with the joints accounting for the majority of the device mass. For example in the case of the SRMS, the entire device mass is 410 kg (904 lbm); the joint structure, motors, gear train, cabling, etc., accounts for the majority of the system mass because the carbon composite tubes mass is 46 kg (101 lbm). An alternate space manipulator concept, the Tendon-Actuated Lightweight In-Space MANipulator (TALISMAN) was created to address deficiencies in the current state-of-the-art in long-reach manipulators. The antagonistic tendon actuated joint architecture allows the motors actuating the joint to be removed from the joint axis, which simplifies the joint design while simultaneously providing mechanical advantage for the motors. The improved mechanical advantage, in turn, reduces the size and power requirements for the motor and gear train. This paper will describe recent architectural improvements to the TALISMAN design that: 1) improve the operational robustness of the

  12. Smart Hand For Manipulators

    NASA Astrophysics Data System (ADS)

    Fiorini, Paolo

    1987-10-01

    Sensor based, computer controlled end effectors for mechanical arms are receiving more and more attention in the robotics industry, because commonly available grippers are only adequate for simple pick and place tasks. This paper describes the current status of the research at JPL on a smart hand for a Puma 560 robot arm. The hand is a self contained, autonomous system, capable of executing high level commands from a supervisory computer. The mechanism consists of parallel fingers, powered by a DC motor, and controlled by a microprocessor embedded in the hand housing. Special sensors are integrated in the hand for measuring the grasp force of the fingers, and for measuring forces and torques applied between the arm and the surrounding environment. Fingers can be exercised under position, velocity and force control modes. The single-chip microcomputer in the hand executes the tasks of communication, data acquisition and sensor based motor control, with a sample cycle of 2 ms and a transmission rate of 9600 baud. The smart hand described in this paper represents a new development in the area of end effector design because of its multi-functionality and autonomy. It will also be a versatile test bed for experimenting with advanced control schemes for dexterous manipulation.

  13. Stereoscopically Observing Manipulative Actions

    PubMed Central

    Ferri, S.; Pauwels, K.; Rizzolatti, G.; Orban, G. A.

    2016-01-01

    The purpose of this study was to investigate the contribution of stereopsis to the processing of observed manipulative actions. To this end, we first combined the factors “stimulus type” (action, static control, and dynamic control), “stereopsis” (present, absent) and “viewpoint” (frontal, lateral) into a single design. Four sites in premotor, retro-insular (2) and parietal cortex operated specifically when actions were viewed stereoscopically and frontally. A second experiment clarified that the stereo-action-specific regions were driven by actions moving out of the frontoparallel plane, an effect amplified by frontal viewing in premotor cortex. Analysis of single voxels and their discriminatory power showed that the representation of action in the stereo-action-specific areas was more accurate when stereopsis was active. Further analyses showed that the 4 stereo-action-specific sites form a closed network converging onto the premotor node, which connects to parietal and occipitotemporal regions outside the network. Several of the specific sites are known to process vestibular signals, suggesting that the network combines observed actions in peripersonal space with gravitational signals. These findings have wider implications for the function of premotor cortex and the role of stereopsis in human behavior. PMID:27252350

  14. Stereoscopically Observing Manipulative Actions.

    PubMed

    Ferri, S; Pauwels, K; Rizzolatti, G; Orban, G A

    2016-08-01

    The purpose of this study was to investigate the contribution of stereopsis to the processing of observed manipulative actions. To this end, we first combined the factors "stimulus type" (action, static control, and dynamic control), "stereopsis" (present, absent) and "viewpoint" (frontal, lateral) into a single design. Four sites in premotor, retro-insular (2) and parietal cortex operated specifically when actions were viewed stereoscopically and frontally. A second experiment clarified that the stereo-action-specific regions were driven by actions moving out of the frontoparallel plane, an effect amplified by frontal viewing in premotor cortex. Analysis of single voxels and their discriminatory power showed that the representation of action in the stereo-action-specific areas was more accurate when stereopsis was active. Further analyses showed that the 4 stereo-action-specific sites form a closed network converging onto the premotor node, which connects to parietal and occipitotemporal regions outside the network. Several of the specific sites are known to process vestibular signals, suggesting that the network combines observed actions in peripersonal space with gravitational signals. These findings have wider implications for the function of premotor cortex and the role of stereopsis in human behavior. PMID:27252350

  15. Risks associated with spinal manipulation.

    PubMed

    Stevinson, Clare; Ernst, Edzard

    2002-05-01

    The aim of this systematic review was to summarize the evidence about the risks of spinal manipulation. Articles were located through searching three electronic databases (MEDLINE, EMBASE, Cochrane Library), contacting experts (n =9), scanning reference lists of relevant articles, and searching departmental files. Reports in any language containing data relating to risks associated with spinal manipulation were included, irrespective of the profession of the therapist. Where available, systematic reviews were used as the basis of this article. All papers were evaluated independently by the authors. Data from prospective studies suggest that minor, transient adverse events occur in approximately half of all patients receiving spinal manipulation. The most common serious adverse events are vertebrobasilar accidents, disk herniation, and cauda equina syndrome. Estimates of the incidence of serious complications range from 1 per 2 million manipulations to 1 per 400,000. Given the popularity of spinal manipulation, its safety requires rigorous investigation. PMID:12015249

  16. Manipulability, force, and compliance analysis for planar continuum manipulators.

    PubMed

    Gravagne, Ian A; Walker, Ian D

    2002-06-01

    Continuum manipulators, inspired by the natural capabilities of elephant trunks and octopus tentacles, may find niche applications in areas like human-robot interaction, multiarm manipulation, and unknown environment exploration. However, their true capabilities will remain largely inaccessible without proper analytical tools to evaluate their unique properties. Ellipsoids have long served as one of the foremost analytical tools available to the robotics researcher, and the purpose of this paper is to first formulate, and then to examine, three types of ellipsoids for continuum robots: manipulability, force, and compliance. PMID:12492083

  17. Manipulability, force, and compliance analysis for planar continuum manipulators

    NASA Technical Reports Server (NTRS)

    Gravagne, Ian A.; Walker, Ian D.

    2002-01-01

    Continuum manipulators, inspired by the natural capabilities of elephant trunks and octopus tentacles, may find niche applications in areas like human-robot interaction, multiarm manipulation, and unknown environment exploration. However, their true capabilities will remain largely inaccessible without proper analytical tools to evaluate their unique properties. Ellipsoids have long served as one of the foremost analytical tools available to the robotics researcher, and the purpose of this paper is to first formulate, and then to examine, three types of ellipsoids for continuum robots: manipulability, force, and compliance.

  18. Long reach cantilevers for sub-cellular force measurements.

    PubMed

    Paneru, Govind; Thapa, Prem S; McBride, Sean P; Ramm, Adam; Law, Bruce M; Flanders, Bret N

    2012-11-16

    Maneuverable, high aspect ratio poly(3,4-ethylene dioxythiophene) (PEDOT) fibers are fabricated for use as cellular force probes that can interface with individual pseudopod adhesive contact sites without forming unintentional secondary contacts to the cell. The straight fibers have lengths between 5 and 40 μm and spring constants in the 0.07-23.2 nN μm(-1) range. The spring constants of these fibers were measured directly using an atomic force microscope (AFM). These AFM measurements corroborate determinations based on the transverse vibrational resonance frequencies of the fibers, which is a more convenient method. These fibers are employed to characterize the time dependent forces exerted at adhesive contacts between apical pseudopods of highly migratory D. discoideum cells and the PEDOT fibers, finding an average terminal force of 3.1 ± 2.7 nN and lifetime of 23.4 ± 18.5 s to be associated with these contacts. PMID:23085541

  19. Direct Manipulation in Virtual Reality

    NASA Technical Reports Server (NTRS)

    Bryson, Steve

    2003-01-01

    Virtual Reality interfaces offer several advantages for scientific visualization such as the ability to perceive three-dimensional data structures in a natural way. The focus of this chapter is direct manipulation, the ability for a user in virtual reality to control objects in the virtual environment in a direct and natural way, much as objects are manipulated in the real world. Direct manipulation provides many advantages for the exploration of complex, multi-dimensional data sets, by allowing the investigator the ability to intuitively explore the data environment. Because direct manipulation is essentially a control interface, it is better suited for the exploration and analysis of a data set than for the publishing or communication of features found in that data set. Thus direct manipulation is most relevant to the analysis of complex data that fills a volume of three-dimensional space, such as a fluid flow data set. Direct manipulation allows the intuitive exploration of that data, which facilitates the discovery of data features that would be difficult to find using more conventional visualization methods. Using a direct manipulation interface in virtual reality, an investigator can, for example, move a data probe about in space, watching the results and getting a sense of how the data varies within its spatial volume.

  20. Sliding Mode Control of a Slewing Flexible Beam

    NASA Technical Reports Server (NTRS)

    Wilson, David G.; Parker, Gordon G.; Starr, Gregory P.; Robinett, Rush D., III

    1997-01-01

    An output feedback sliding mode controller (SMC) is proposed to minimize the effects of vibrations of slewing flexible manipulators. A spline trajectory is used to generate ideal position and velocity commands. Constrained nonlinear optimization techniques are used to both calibrate nonlinear models and determine optimized gains to produce a rest-to-rest, residual vibration-free maneuver. Vibration-free maneuvers are important for current and future NASA space missions. This study required the development of the nonlinear dynamic system equations of motion; robust control law design; numerical implementation; system identification; and verification using the Sandia National Laboratories flexible robot testbed. Results are shown for a slewing flexible beam.

  1. Autonomous Object Manipulation Using a Soft Planar Grasping Manipulator

    PubMed Central

    Katzschmann, Robert K.; Marchese, Andrew D.

    2015-01-01

    Abstract This article presents the development of an autonomous motion planning algorithm for a soft planar grasping manipulator capable of grasp-and-place operations by encapsulation with uncertainty in the position and shape of the object. The end effector of the soft manipulator is fabricated in one piece without weakening seams using lost-wax casting instead of the commonly used multilayer lamination process. The soft manipulation system can grasp randomly positioned objects within its reachable envelope and move them to a desired location without human intervention. The autonomous planning system leverages the compliance and continuum bending of the soft grasping manipulator to achieve repeatable grasps in the presence of uncertainty. A suite of experiments is presented that demonstrates the system's capabilities. PMID:27625916

  2. Manipulator control by exact linearization

    NASA Technical Reports Server (NTRS)

    Kruetz, K.

    1987-01-01

    Comments on the application to rigid link manipulators of geometric control theory, resolved acceleration control, operational space control, and nonlinear decoupling theory are given, and the essential unity of these techniques for externally linearizing and decoupling end effector dynamics is discussed. Exploiting the fact that the mass matrix of a rigid link manipulator is positive definite, a consequence of rigid link manipulators belonging to the class of natural physical systems, it is shown that a necessary and sufficient condition for a locally externally linearizing and output decoupling feedback law to exist is that the end effector Jacobian matrix be nonsingular. Furthermore, this linearizing feedback is easy to produce.

  3. Kinematic sensitivity of robot manipulators

    NASA Technical Reports Server (NTRS)

    Vuskovic, Marko I.

    1989-01-01

    Kinematic sensitivity vectors and matrices for open-loop, n degrees-of-freedom manipulators are derived. First-order sensitivity vectors are defined as partial derivatives of the manipulator's position and orientation with respect to its geometrical parameters. The four-parameter kinematic model is considered, as well as the five-parameter model in case of nominally parallel joint axes. Sensitivity vectors are expressed in terms of coordinate axes of manipulator frames. Second-order sensitivity vectors, the partial derivatives of first-order sensitivity vectors, are also considered. It is shown that second-order sensitivity vectors can be expressed as vector products of the first-order sensitivity vectors.

  4. Multifunctional, Highly Flexible, Free-Standing 3D Polypyrrole Foam.

    PubMed

    Wang, Chunhui; Ding, Yujie; Yuan, Ye; Cao, Anyuan; He, Xiaodong; Peng, Qingyu; Li, Yibin

    2016-08-01

    Multifunctional, highly flexible 3D polypyrrole (PPy) foam is fabricated via a simple electrodeposition method by using nickel foam as the template. The 3D PPy foam has a unique interior structure and is robust enough to manipulate directly. PMID:27357260

  5. The Role of Goal Representation in Preschoolers' Flexibility and Inhibition

    ERIC Educational Resources Information Center

    Blaye, Agnes; Chevalier, Nicolas

    2011-01-01

    This study addressed the role of goal representation in preschoolers' inhibition and flexibility performance. A total of 56 4- and 5-year-olds were tested in an adapted version of the Shape School task where the difficulty of goal representation was manipulated by varying the degree of transparency of task cues. The findings showed that both age…

  6. Development of 3 DOF manipulator using ER fluid clutches for reduction of collision force

    NASA Astrophysics Data System (ADS)

    Boku, Kazuhiko; Nakamura, Taro

    2009-02-01

    .With robots and users more commonly sharing space such as in the fields of medicine and home automation, the possibility of a physical collision has increased, even though many robots use actuators with high-ratio gear trains to minimize the effects of impact. We developed a 3-DOF manipulator having a smart flexible joint using an ER fluid and a sensor-equipped pneumatic cushion. Results of position control and collision experiments using the manipulator demonstrated its effectiveness.

  7. Machine intelligence for autonomous manipulation.

    NASA Technical Reports Server (NTRS)

    Bejczy, A. K.

    1973-01-01

    Survey of the present technological development status of machine intelligence for autonomous manipulation in the U.S., Japan, USSR, and England. The extent of task-performance autonomy is examined that machine intelligence gives the manipulator by eliminating the need for a human operator to close continuously the control loop, or to rewrite control programs for each different task. Surveyed research projects show that the development of some advanced automation systems for manipulator control are within the state of the art. Yet, many more realistic breadboard systems and experimental work are needed before further progress can be made in the design of advanced automation systems for manipulator control suitable for new major practical applications. Specific research areas of promise are pointed out.

  8. Optodynamic description of optical manipulation

    NASA Astrophysics Data System (ADS)

    Požar, Tomaž; Možina, Janez

    2015-08-01

    Optodynamics treats optical manipulation as a superposition of time-developing wave motion induced by a light-matter interaction. When an opaque solid object is manipulated by a pulse of light, various types of mechanical waves are launched from the illuminated surface: ablation-induced waves (AIWs) resulting from material recoil, thermoelastic waves (TEWs), and the light-pressure-induced waves (LIWs) emanating exclusively due to radiation pressure. The manipulated object's boundaries experience staircase-like displacements with discrete steps caused either by AIWs or LIWs each time these waves are reflected from the interfaces. On the contrary, TEWs cannot translate the center of mass of the manipulated object, but their presence can be inferred from the transient, bi-polar displacements around the equilibrium position.

  9. Building Fractal Models with Manipulatives.

    ERIC Educational Resources Information Center

    Coes, Loring

    1993-01-01

    Uses manipulative materials to build and examine geometric models that simulate the self-similarity properties of fractals. Examples are discussed in two dimensions, three dimensions, and the fractal dimension. Discusses how models can be misleading. (Contains 10 references.) (MDH)

  10. Chaos motion in robot manipulators

    NASA Technical Reports Server (NTRS)

    Lokshin, A.; Zak, M.

    1987-01-01

    It is shown that a simple two-link planar manipulator exhibits a phenomenon of global instability in a subspace of its configuration space. A numerical example, as well as results of a graphic simulation, is given.

  11. Task Board Tests Manipulator Performance

    NASA Technical Reports Server (NTRS)

    Hill, J. W.

    1983-01-01

    Task board constructed to facilitate time-and-motion studies for remote manipulators. Apparatus equipped with holes, objects of various shapes to be grasped and sensors with switches to indicate contact. Useful in industrial robots programmed to assemble parts.

  12. Concept development of a tendon arm manipulator and anthropomorphic robotic hand

    NASA Technical Reports Server (NTRS)

    Tolman, C. T.

    1987-01-01

    AMETEK/ORED inhouse research and development efforts leading toward a next-generation robotic manipulator arm and end-effector technology is summarized. Manipulator arm development has been directed toward a multiple-degree-of-freedom, flexible, tendon-driven concept referred to here as a Tendon Arm Manipulator (TAM). End-effector development has been directed toward a three-fingered, dextrous, tendon-driven, anthropomorphic configuration which is referred to as an Anthropomorphic Robotic Hand (ARH). Key technology issues are identified for both concepts.

  13. Berthing of Space Station Freedom using the shuttle remote manipulator system

    NASA Technical Reports Server (NTRS)

    Cooper, Paul; Demeo, Martha E.

    1993-01-01

    A large-angle, flexible, multi-body, dynamic modeling capability was developed to help validate analytical simulations of the dynamic motion and control forces which occur while berthing of Space Station Freedom to the Shuttle Orbiter during early assembly flights. The dynamics and control of the station, the attached Shuttle Remote Manipulator System, and the Orbiter during a berthing maneuver are described. Emphasis is placed on the modeling of the Shuttle Remote Manipulator System in the multi-body simulation. The influence of the elastic behavior of the station and of the Remote Manipulator System on the attitude control of the station/Orbiter system during the maneuver is investigated.

  14. Using a 1.2 GHz bandwidth reflective semiconductor optical amplifier with seeding light by 64-quadrature amplitude modulation orthogonal frequency division multiplexing modulation to achieve a 10-gbits/s upstream rate in long-reach passive optical network access

    NASA Astrophysics Data System (ADS)

    Yeh, Chien-Hung; Chen, Hsing-Yu; Chow, Chi-Wai; Wu, Yu-Fu

    2012-01-01

    We use a commercially available 1.2 GHz bandwidth reflective semiconductor optical amplifier (RSOA)--based optical network unit (ONU) to achieve 10-gbits/s upstream traffic for an optical orthogonal frequency division multiplexing (OFDM) long-reach passive optical network (LR-PON). This is the first time the 64--quadrature amplitude modulation (QAM) OFDM format has been applied to RSOA-ONU to achieve a 75 km fiber transmission length. In the proposed LR-PON, the upstream power penalty of 5.2 dB at the bit error rate of 3.8×10-3 is measured by using a 64-QAM OFDM modulation after the 75 km fiber transmission without dispersion compensation.

  15. Assumed modes method and flexible multibody dynamics

    NASA Technical Reports Server (NTRS)

    Tadikonda, S. S. K.; Mordfin, T. G.; Hu, T. G.

    1993-01-01

    The use of assumed modes in flexible multibody dynamics algorithms requires the evaluation of several domain dependent integrals that are affected by the type of modes used. The implications of these integrals - often called zeroth, first and second order terms - are investigated in this paper, for arbitrarily shaped bodies. Guidelines are developed for the use of appropriate boundary conditions while generating the component modal models. The issue of whether and which higher order terms must be retained is also addressed. Analytical results, and numerical results using the Shuttle Remote Manipulator System as the multibody system, are presented to qualitatively and quantitatively address these issues.

  16. Adaptive path planning for flexible manufacturing

    SciTech Connect

    Chen, Pang C.

    1994-08-01

    Path planning needs to be fast to facilitate real-time robot programming. Unfortunately, current planning techniques are still too slow to be effective, as they often require several minutes, if not hours of computation. To overcome this difficulty, we present an adaptive algorithm that uses past experience to speed up future performance. It is a learning algorithm suitable for automating flexible manufacturing in incrementally-changing environments. The algorithm allows the robot to adapt to its environment by having two experience manipulation schemes: For minor environmental change, we use an object-attached experience abstraction scheme to increase the flexibility of the learned experience; for major environmental change, we use an on-demand experience repair scheme to retain those experiences that remain valid and useful. Using this algorithm, we can effectively reduce the overall robot planning time by re-using the computation result for one task to plan a path for another.

  17. Elastomeric composites for flexible microwave substrates

    NASA Astrophysics Data System (ADS)

    Awang, Robiatun A.; Baum, Thomas; Berean, Kyle J.; Yi, Pyshar; Kalantar-zadeh, Kourosh; Sriram, Sharath; Rowe, Wayne S. T.

    2016-03-01

    Manipulating dielectric properties of polydimethylsiloxane (PDMS) is an important consideration for flexible, low-loss device design. This paper presents a method for reducing dielectric loss (tan δ) by forming PDMS composites loaded with various concentrations of either alumina (Al2O3) or polytetrafluoroethylene (PTFE) particles. The structural, mechanical, and electrical properties of the composites are investigated. Theoretical mixing models were used to predict the relative permittivity (ɛr) of PDMS composites, and good similarity with the measured ɛr was observed. The incorporation of either low dielectric loss filler in the PDMS matrix (up to 50 wt. % filler loading) is shown to reduce the dielectric loss while maintaining the flexibility of the host matrix. The fillers can also control the permittivity of the composite, either increasing or decreasing relative permittivity from that of PDMS. Interestingly, a strain of ˜500% can be applied to 15 wt. % PDMS/PTFE composites, compared with ˜350% for pure PDMS.

  18. Flexibility, Is That All?

    ERIC Educational Resources Information Center

    Renes, Wim M.

    This paper discusses the design of flexible and intelligent library buildings. The first section addresses how flexibility, as one of the requirements of a library building, that has high priority in the planning process. Intelligent libraries are considered in the second section, and functionality is stressed. The third section examines…

  19. Shear flexibility for structures

    NASA Technical Reports Server (NTRS)

    Stangeland, Maynard L. (Inventor)

    1976-01-01

    This device comprises a flexible sheet member having cross convolutions oriented 45.degree. to the shear vector with spherical reliefs at the convolution junctions. The spherical reliefs are essential to the shear flexibility by interrupting the principal stress lines that act along the ridges of the convolutions. The spherical reliefs provide convolutions in both directions in the plane of the cross-convolution ridges.

  20. Shear flexibility for structures

    NASA Technical Reports Server (NTRS)

    Stangeland, Maynard L. (Inventor)

    1977-01-01

    This device comprises a flexible sheet member having cross convolutions oriented 45.degree. to the shear vector with spherical reliefs at the convolution junctions. The spherical reliefs are essential to the shear flexibility by interrupting the principal stress lines that act along the ridges of the convolutions. The spherical reliefs provide convolutions in both directions in the plane of the cross-convolution ridges.

  1. Flexible Learning Opportunities.

    ERIC Educational Resources Information Center

    Further Education Unit, London (England).

    One way for colleges to meet the demand for a wider range of learning opportunities for adults in Great Britain is to provide more flexibility within the further education system. The concept of flexible learning involves the modification of delivery systems, specific providing agencies, target populations, specific determinants such as geographic…

  2. Flexible Heat Pipe

    NASA Technical Reports Server (NTRS)

    Bienert, W. B.; Wolf, D. A.

    1985-01-01

    Narrow Tube carries 10 watts or more to moving parts. Heat pipe 12 inches long and diameter of 0.312 inch (7.92mm). Bent to minimum radius of 2.5 blocks. Flexible section made of 321 stainless steel tubing (Cajon Flexible Tubing or equivalent). Evaporator and condenser made of oxygen free copper. Working fluid methanol.

  3. Flexible Animation Computer Program

    NASA Technical Reports Server (NTRS)

    Stallcup, Scott S.

    1990-01-01

    FLEXAN (Flexible Animation), computer program animating structural dynamics on Evans and Sutherland PS300-series graphics workstation with VAX/VMS host computer. Typical application is animation of spacecraft undergoing structural stresses caused by thermal and vibrational effects. Displays distortions in shape of spacecraft. Program displays single natural mode of vibration, mode history, or any general deformation of flexible structure. Written in FORTRAN 77.

  4. Flexibility within Fidelity

    ERIC Educational Resources Information Center

    Kendall, Philip C.; Gosch, Elizabeth; Furr, Jami M.; Sood, Erica

    2008-01-01

    The authors address concerns regarding manual-based treatments, highlighting the role of flexibility and creativity. A cognitive-behavioral therapy for youth anxiety called the Coping Cat program demonstrates the flexible application of manuals and emphasizes the importance of a child-centered, personalized approach that involves the child in the…

  5. Shield For Flexible Pipe

    NASA Technical Reports Server (NTRS)

    Ponton, Michael K.; Williford, Clifford B.; Lagen, Nicholas T.

    1995-01-01

    Cylindrical shield designed to fit around flexible pipe to protect nearby workers from injury and equipment from damage if pipe ruptures. Designed as pressure-relief device. Absorbs impact of debris ejected radially from broken flexible pipe. Also redirects flow of pressurized fluid escaping from broken pipe onto flow path allowing for relief of pressure while minimizing potential for harm.

  6. Mobile camera-space manipulation

    NASA Technical Reports Server (NTRS)

    Seelinger, Michael J. (Inventor); Yoder, John-David S. (Inventor); Skaar, Steven B. (Inventor)

    2001-01-01

    The invention is a method of using computer vision to control systems consisting of a combination of holonomic and nonholonomic degrees of freedom such as a wheeled rover equipped with a robotic arm, a forklift, and earth-moving equipment such as a backhoe or a front-loader. Using vision sensors mounted on the mobile system and the manipulator, the system establishes a relationship between the internal joint configuration of the holonomic degrees of freedom of the manipulator and the appearance of features on the manipulator in the reference frames of the vision sensors. Then, the system, perhaps with the assistance of an operator, identifies the locations of the target object in the reference frames of the vision sensors. Using this target information, along with the relationship described above, the system determines a suitable trajectory for the nonholonomic degrees of freedom of the base to follow towards the target object. The system also determines a suitable pose or series of poses for the holonomic degrees of freedom of the manipulator. With additional visual samples, the system automatically updates the trajectory and final pose of the manipulator so as to allow for greater precision in the overall final position of the system.

  7. High precision redundant robotic manipulator

    DOEpatents

    Young, K.K.D.

    1998-09-22

    A high precision redundant robotic manipulator for overcoming contents imposed by obstacles or imposed by a highly congested work space is disclosed. One embodiment of the manipulator has four degrees of freedom and another embodiment has seven degrees of freedom. Each of the embodiments utilize a first selective compliant assembly robot arm (SCARA) configuration to provide high stiffness in the vertical plane, a second SCARA configuration to provide high stiffness in the horizontal plane. The seven degree of freedom embodiment also utilizes kinematic redundancy to provide the capability of avoiding obstacles that lie between the base of the manipulator and the end effector or link of the manipulator. These additional three degrees of freedom are added at the wrist link of the manipulator to provide pitch, yaw and roll. The seven degrees of freedom embodiment uses one revolute point per degree of freedom. For each of the revolute joints, a harmonic gear coupled to an electric motor is introduced, and together with properly designed based servo controllers provide an end point repeatability of less than 10 microns. 3 figs.

  8. High precision redundant robotic manipulator

    DOEpatents

    Young, Kar-Keung David

    1998-01-01

    A high precision redundant robotic manipulator for overcoming contents imposed by obstacles or imposed by a highly congested work space. One embodiment of the manipulator has four degrees of freedom and another embodiment has seven degreed of freedom. Each of the embodiments utilize a first selective compliant assembly robot arm (SCARA) configuration to provide high stiffness in the vertical plane, a second SCARA configuration to provide high stiffness in the horizontal plane. The seven degree of freedom embodiment also utilizes kinematic redundancy to provide the capability of avoiding obstacles that lie between the base of the manipulator and the end effector or link of the manipulator. These additional three degrees of freedom are added at the wrist link of the manipulator to provide pitch, yaw and roll. The seven degrees of freedom embodiment uses one revolute point per degree of freedom. For each of the revolute joints, a harmonic gear coupled to an electric motor is introduced, and together with properly designed based servo controllers provide an end point repeatability of less than 10 microns.

  9. Learning Area and Perimeter with Virtual Manipulatives

    ERIC Educational Resources Information Center

    Bouck, Emily; Flanagan, Sara; Bouck, Mary

    2015-01-01

    Manipulatives are considered a best practice for educating students with disabilities, but little research exists which examines virtual manipulatives as tool for supporting students in mathematics. This project investigated the use of a virtual manipulative through the National Library of Virtual Manipulatives--polynominoes (i.e., tiles)--as a…

  10. Dynamics modelling and Hybrid Suppression Control of space robots performing cooperative object manipulation

    NASA Astrophysics Data System (ADS)

    Zarafshan, P.; Moosavian, S. Ali A.

    2013-10-01

    Dynamics modelling and control of multi-body space robotic systems composed of rigid and flexible elements is elaborated here. Control of such systems is highly complicated due to severe under-actuated condition caused by flexible elements, and an inherent uneven nonlinear dynamics. Therefore, developing a compact dynamics model with the requirement of limited computations is extremely useful for controller design, also to develop simulation studies in support of design improvement, and finally for practical implementations. In this paper, the Rigid-Flexible Interactive dynamics Modelling (RFIM) approach is introduced as a combination of Lagrange and Newton-Euler methods, in which the motion equations of rigid and flexible members are separately developed in an explicit closed form. These equations are then assembled and solved simultaneously at each time step by considering the mutual interaction and constraint forces. The proposed approach yields a compact model rather than common accumulation approach that leads to a massive set of equations in which the dynamics of flexible elements is united with the dynamics equations of rigid members. To reveal such merits of this new approach, a Hybrid Suppression Control (HSC) for a cooperative object manipulation task will be proposed, and applied to usual space systems. A Wheeled Mobile Robotic (WMR) system with flexible appendages as a typical space rover is considered which contains a rigid main body equipped with two manipulating arms and two flexible solar panels, and next a Space Free Flying Robotic system (SFFR) with flexible members is studied. Modelling verification of these complicated systems is vigorously performed using ANSYS and ADAMS programs, while the limited computations of RFIM approach provides an efficient tool for the proposed controller design. Furthermore, it will be shown that the vibrations of the flexible solar panels results in disturbing forces on the base which may produce undesirable errors

  11. A grid quality manipulation system

    NASA Technical Reports Server (NTRS)

    Lu, Ning; Eiseman, Peter R.

    1991-01-01

    A grid quality manipulation system is described. The elements of the system are the measures by which quality is assessed, the computer graphic display of those measures, and the local grid manipulation to provide a response to the viewed quality indication. The display is an overlaid composite where the region is first covered with colors to reflect the values of the quality indicator, the grid is then placed on top of those colors, and finally a control net is placed on top of everything. The net represents the grid in terms of the control point form of algebraic grid generation. As a control point is moved, both the grid and the colored quality measures also move. This is a real time dynamic action so that the consequences of the manipulation are continuously seen.

  12. Manipulating Complex Light with Metamaterials

    PubMed Central

    Zeng, Jinwei; Wang, Xi; Sun, Jingbo; Pandey, Apra; Cartwright, Alexander N.; Litchinitser, Natalia M.

    2013-01-01

    Recent developments in the field of metamaterials have revealed unparalleled opportunities for “engineering” space for light propagation; opening a new paradigm in spin- and quantum-related phenomena in optical physics. Here we show that unique optical properties of metamaterials (MMs) open unlimited prospects to “engineer” light itself. We propose and demonstrate for the first time a novel way of complex light manipulation in few-mode optical fibers using optical MMs. Most importantly, these studies highlight how unique properties of MMs, namely the ability to manipulate both electric and magnetic field components of electromagnetic (EM) waves, open new degrees of freedom in engineering complex polarization states of light at will, while preserving its orbital angular momentum (OAM) state. These results lay the first steps in manipulating complex light in optical fibers, likely providing new opportunities for high capacity communication systems, quantum information, and on-chip signal processing. PMID:24084836

  13. Mapping and Manipulating Facial Expression

    PubMed Central

    Theobald, Barry-John; Matthews, Iain; Mangini, Michael; Spies, Jeffrey R.; Brick, Timothy R.; Cohn, Jeffrey F.; Boker, Steven M.

    2009-01-01

    Non-verbal visual cues accompany speech to supplement the meaning of spoken words, signify emotional state, indicate position in discourse, and provide back-channel feedback. This visual information includes head movements, facial expressions and body gestures. In this paper we describe techniques for manipulating both verbal and non-verbal facial gestures in video sequences of people engaged in conversation. We are developing a system for use in psychological experiments, where the effects of manipulating individual components of non-verbal visual behaviour during live face-to-face conversation can be studied. In particular, the techniques we describe operate in real-time at video frame-rate and the manipulation can be applied so both participants in a conversation are kept blind to the experimental conditions. PMID:19624037

  14. Understanding pharmaceutical research manipulation in the context of accounting manipulation.

    PubMed

    Brown, Abigail

    2013-01-01

    The problem of the manipulation of data that arises when there is both opportunity and incentive to mislead is better accepted and studied - though by no means solved - in financial accounting than in medicine. This article analyzes pharmaceutical company manipulation of medical research as part of a broader problem of corporate manipulation of data in the creation of accounting profits. The article explores how our understanding of accounting fraud and misinformation helps us understand the risk of similar information manipulation in the medical sciences. This understanding provides a framework for considering how best to improve the quality of medical research and analysis in light of the current system of medical information production. I offer three possible responses: (1) use of the Dodd-Frank whistleblower provisions to encourage reporting of medical research fraud; (2) a two-step academic journal review process for clinical trials; and (3) publicly subsidized trial-failure insurance. These would improve the release of negative information about drugs, thereby increasing the reliability of positive information. PMID:24088151

  15. Rolling cuff flexible bellows

    DOEpatents

    Lambert, Donald R.

    1985-01-01

    A flexible connector apparatus used to join two stiff non-deformable members, such as piping. The apparatus is provided with one or more flexible sections or assemblies each utilizing a bellows of a rolling cuff type connected between two ridge members, with the bellows being supported by a back-up ring, such that only the curved end sections of the bellows are unsupported. Thus, the bellows can be considered as being of a tube-shaped configuration and thus have high pressure resistance. The components of the flexible apparatus are sealed or welded one to another such that it is fluid tight.

  16. Rolling cuff flexible bellows

    SciTech Connect

    Lambert, D. R.

    1985-09-10

    A flexible connector apparatus used to join two stiff non-deformable members, such as piping. The apparatus is provided with one or more flexible sections or assemblies each utilizing a bellows of a rolling cuff type connected between two ridge members, with the bellows being supported by a back-up ring, such that only the curved end sections of the bellows are unsupported. Thus, the bellows can be considered as being of a tube-shaped configuration and thus have high pressure resistance. The components of the flexible apparatus are sealed or welded one to another such that it is fluid tight.

  17. Analysis of parameter sensitivity of space manipulator with harmonic drive based on the revised response surface method

    NASA Astrophysics Data System (ADS)

    Zhao, Jieliang; Yan, Shaoze; Wu, Jianing

    2014-05-01

    Space manipulator is an important tool for spacecraft to complete a variety of tasks in space. Nowadays the harmonic drive is widely used as the reducer in the space manipulator, which may influence the dynamical properties of flexible space manipulator. The analysis of dynamic reliability and parameter sensitivity of space manipulator with harmonic drive is of significant importance for space manipulator designers in the early stage of design. The trajectory precision of the manipulator determines whether the mechanism performs normally. However, it is difficult to use the existing methods to resolve reliability apportionment issues because of the data insufficiency and the uncertainty of the relations among the components in the mechanical system. This paper establishes the dynamical models of space manipulator considering the harmonic hysteresis phenomenon derived from the harmonic reducer. A new method is proposed to analyze the dynamic reliability and parameter sensitivity of space manipulator with harmonic drive. The proposed method extends the previous response surface method (RSM) and focuses on the characteristics of the output dynamical property of the space manipulator. With the result of parameter sensitivity analysis, we can prolong the fine arm or shorten the main arm to improve the motion precision reliability of space manipulator. Therefore, our revised response surface method (RRSM) is suitable for reliability apportionment of the space manipulator when the design information has not been clearly identified, particularly in early design phrase.

  18. Manipulating Genetic Material in Bacteria

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Lisa Crawford, a graduate research assistant from the University of Toledo, works with Laurel Karr of Marshall Space Flight Center (MSFC) in the molecular biology laboratory. They are donducting genetic manipulation of bacteria and yeast for the production of large amount of desired protein. Photo credit: NASA/Marshall Space Flight Center (MSFC)

  19. Master/slave manipulator system

    NASA Technical Reports Server (NTRS)

    Vykukal, H. C.; King, R. F.; Vallotton, W. C.

    1973-01-01

    System capabilities are equivalent to mobility, dexterity, and strength of human arm. Arrangement of torque motor, harmonic drive, and potentiometer combination allows all power and control leads to pass through center of slave with position-transducer arrangement of master, and "stovepipe joint" is incorporated for manipulator applications.

  20. DATACUBE: A datacube manipulation package

    NASA Astrophysics Data System (ADS)

    Allan, Alasdair; Currie, Malcolm J.

    2014-05-01

    DATACUBE is a command-line package for manipulating and visualizing data cubes. It was designed for integral field spectroscopy but has been extended to be a generic data cube tool, used in particular for sub-millimeter data cubes from the James Clerk Maxwell Telescope. It is part of the Starlink software collection (ascl:1110.012).

  1. COGNITION, ACTION, AND OBJECT MANIPULATION

    PubMed Central

    Rosenbaum, David A.; Chapman, Kate M.; Weigelt, Matthias; Weiss, Daniel J.; van der Wel, Robrecht

    2012-01-01

    Although psychology is the science of mental life and behavior, it has paid little attention to the means by which mental life is translated into behavior. One domain where links between cognition and action have been explored is the manipulation of objects. This article reviews psychological research on this topic, with special emphasis on the tendency to grasp objects differently depending on what one plans to do with the objects. Such differential grasping has been demonstrated in a wide range of object manipulation tasks, including grasping an object in a way that reveals anticipation of the object's future orientation, height, and required placement precision. Differential grasping has also been demonstrated in a wide range of behaviors, including one-hand grasps, two-hand grasps, walking, and transferring objects from place to place as well as from person to person. The populations in whom the tendency has been shown are also diverse, including nonhuman primates as well as human adults, children, and babies. Meanwhile, the tendency is compromised in a variety of clinical populations and in children of a surprisingly advanced age. Verbal working memory is compromised as well if words are memorized while object manipulation tasks are performed; the recency portion of the serial position curve is reduced in this circumstance. In general, the research reviewed here points to rich connections between cognition and action as revealed through the study of object manipulation. Other implications concern affordances, Donders' Law, and naturalistic observation and the teaching of psychology. PMID:22448912

  2. Ants: the supreme soil manipulators

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This review focuses on the semiochemical interactions between ants and their soil environment. Ants occupy virtually every ecological niche and have evolved mechanisms to not just cope with, but also manipulate soil organisms. The metapleural gland, specific to ants was thought to be the major sourc...

  3. Adaptive Control Of Remote Manipulator

    NASA Technical Reports Server (NTRS)

    Seraji, Homayoun

    1989-01-01

    Robotic control system causes remote manipulator to follow closely reference trajectory in Cartesian reference frame in work space, without resort to computationally intensive mathematical model of robot dynamics and without knowledge of robot and load parameters. System, derived from linear multivariable theory, uses relatively simple feedforward and feedback controllers with model-reference adaptive control.

  4. Advanced action manipulator system (ADAMS)

    NASA Technical Reports Server (NTRS)

    Kugath, D. A.; Dane, D. H.; Blaise, H. T.

    1973-01-01

    Manipulator offers improved performance over other models in its category. It features larger force and reach capabilities and is readily convertible for underwater use. Unique kinematic arrangement provides extremely large working envelope. System has six degrees of motion: azimuth joint, shoulder joint, upper arm rotating joint, elbow joint, wrist pitch, and wrist twist.

  5. Teaching Integration Applications Using Manipulatives

    ERIC Educational Resources Information Center

    Bhatia, Kavita; Premadasa, Kirthi; Martin, Paul

    2014-01-01

    Calculus students' difficulties in understanding integration have been extensively studied. Research shows that the difficulty lies with students understanding of the definition of the definite integral as a limit of a Riemann sum and with the idea of accumulation inherent in integration. We have created a set of manipulatives and activities…

  6. Mapping and Manipulating Facial Expression

    ERIC Educational Resources Information Center

    Theobald, Barry-John; Matthews, Iain; Mangini, Michael; Spies, Jeffrey R.; Brick, Timothy R.; Cohn, Jeffrey F.; Boker, Steven M.

    2009-01-01

    Nonverbal visual cues accompany speech to supplement the meaning of spoken words, signify emotional state, indicate position in discourse, and provide back-channel feedback. This visual information includes head movements, facial expressions and body gestures. In this article we describe techniques for manipulating both verbal and nonverbal facial…

  7. Manipulating stored images with phase imprinting at low light levels.

    PubMed

    Zhao, L; Yang, Guojian; Duan, Wenhui

    2012-07-15

    Coherent manipulation of stored images is performed at low light levels based on enhanced cross-Kerr nonlinearity in a four-level N-type electromagnetically induced transparency (EIT) system. Using intensity masks in the signal pulse, quadratic phase shifts with low nonlinear absorption can be efficiently imprinted on the Fraunhofer diffraction patterns already stored in the EIT system. Fast-Fourier-transform-based numerical simulations clearly demonstrate that the far-field images of the retrieved probe light can be flexibly modulated by applying different signal fields. Our studies could help advance the goals of nonlinear all-optical processing for spatial information coherently stored in EIT systems. PMID:22825156

  8. Discrete-time adaptive control of robot manipulators

    NASA Technical Reports Server (NTRS)

    Tarokh, M.

    1989-01-01

    A discrete-time model reference adaptive control scheme is developed for trajectory tracking of robot manipulators. Hyperstability theory is utilized to derive the adaptation laws for the controller gain matrices. It is shown that asymptotic trajectory tracking is achieved despite gross robot parameter variation and uncertainties. The method offers considerable design flexibility and enables the designer to improve the performance of the control system by adjusting free design parameters. The discrete-time adaptation algorithm is extremely simple and is therefore suitable for real-time implementation.

  9. Flexibility in insulin prescription

    PubMed Central

    Kalra, Sanjay; Gupta, Yashdeep; Unnikrishnan, Ambika Gopalakrishnan

    2016-01-01

    This communication explores the concept of flexibility, a propos insulin preparations and insulin regimes used in the management of type 2 diabetes. The flexibility of an insulin regime or preparation is defined as their ability to be injected at variable times, with variable injection-meal time gaps, in a dose frequency and quantum determined by shared decision making, with a minimal requirement of glucose monitoring and health professional consultation, with no compromise on safety, efficiency and tolerability. The relative flexibility of various basal, prandial and dual action insulins, as well as intensive regimes, is compared. The biopsychosocial model of health is used to assess the utility of different insulins while encouraging a philosophy of flexible insulin usage. PMID:27186563

  10. Modeling flexible active nematics

    NASA Astrophysics Data System (ADS)

    Varga, Michael; Selinger, Robin

    We study active nematic phases of self-propelled flexible chains in two dimensions using computer simulation, to investigate effects of chain flexibility. In a ``dry'' phase of self-propelled flexible chains, we find that increasing chain stiffness enhances orientational order and correlation length, narrows the distribution of turning angles, increases persistence length, and increases the magnitude of giant density fluctuations. We further adapt the simulation model to describe behavior of microtubules driven by kinesin molecular motors in two different environments: on a rigid substrate with kinesin immobilized on the surface; and on a lipid membrane where kinesin is bonded to lipid head groups and can diffuse. Results are compared to experiments by L. Hirst and J. Xu. Lastly, we consider active nematics of flexible particles enclosed in soft, deformable encapsulation in two dimensions, and demonstrate novel mechanisms of pattern formation that are fundamentally different from those observed in bulk. Supported by NSF-DMR 1409658.

  11. Composite flexible blanket insulation

    NASA Technical Reports Server (NTRS)

    Kourtides, Demetrius A. (Inventor); Lowe, David M. (Inventor)

    1994-01-01

    An improved composite flexible blanket insulation is presented comprising top silicon carbide having an interlock design, wherein the reflective shield is composed of single or double aluminized polyimide and wherein the polyimide film has a honeycomb pattern.

  12. Flexible memory networks.

    PubMed

    Curto, Carina; Degeratu, Anda; Itskov, Vladimir

    2012-03-01

    Networks of neurons in some brain areas are flexible enough to encode new memories quickly. Using a standard firing rate model of recurrent networks, we develop a theory of flexible memory networks. Our main results characterize networks having the maximal number of flexible memory patterns, given a constraint graph on the network's connectivity matrix. Modulo a mild topological condition, we find a close connection between maximally flexible networks and rank 1 matrices. The topological condition is H (1)(X;ℤ)=0, where X is the clique complex associated to the network's constraint graph; this condition is generically satisfied for large random networks that are not overly sparse. In order to prove our main results, we develop some matrix-theoretic tools and present them in a self-contained section independent of the neuroscience context. PMID:21826564

  13. Flexible Polyhedral Surfaces.

    ERIC Educational Resources Information Center

    Alexandrov, V. A.

    1998-01-01

    Discusses some questions connected with Cauchy's theorem which states that two convex closed polyhedral surfaces whose corresponding faces are congruent and whose faces adjoin each other in the same way are congruent. Describes how to construct a flexible polyhedron. (ASK)

  14. Flexibility in insulin prescription.

    PubMed

    Kalra, Sanjay; Gupta, Yashdeep; Unnikrishnan, Ambika Gopalakrishnan

    2016-01-01

    This communication explores the concept of flexibility, a propos insulin preparations and insulin regimes used in the management of type 2 diabetes. The flexibility of an insulin regime or preparation is defined as their ability to be injected at variable times, with variable injection-meal time gaps, in a dose frequency and quantum determined by shared decision making, with a minimal requirement of glucose monitoring and health professional consultation, with no compromise on safety, efficiency and tolerability. The relative flexibility of various basal, prandial and dual action insulins, as well as intensive regimes, is compared. The biopsychosocial model of health is used to assess the utility of different insulins while encouraging a philosophy of flexible insulin usage. PMID:27186563

  15. Computational control of flexible aerospace systems

    NASA Technical Reports Server (NTRS)

    Sharpe, Lonnie, Jr.; Shen, Ji Yao

    1994-01-01

    The main objective of this project is to establish a distributed parameter modeling technique for structural analysis, parameter estimation, vibration suppression and control synthesis of large flexible aerospace structures. This report concentrates on the research outputs produced in the last two years. The main accomplishments can be summarized as follows. A new version of the PDEMOD Code had been completed based on several incomplete versions. The verification of the code had been conducted by comparing the results with those examples for which the exact theoretical solutions can be obtained. The theoretical background of the package and the verification examples has been reported in a technical paper submitted to the Joint Applied Mechanics & Material Conference, ASME. A brief USER'S MANUAL had been compiled, which includes three parts: (1) Input data preparation; (2) Explanation of the Subroutines; and (3) Specification of control variables. Meanwhile, a theoretical investigation of the NASA MSFC two-dimensional ground-based manipulator facility by using distributed parameter modeling technique has been conducted. A new mathematical treatment for dynamic analysis and control of large flexible manipulator systems has been conceived, which may provide an embryonic form of a more sophisticated mathematical model for future modified versions of the PDEMOD Codes.

  16. A Novel Flexible Virtual Fixtures for Teleoperation

    PubMed Central

    2014-01-01

    This paper proposed a novel spatial-motion-constraints virtual fixtures (VFs) method for the human-machine interface collaborative technique. In our method, two 3D flexible VFs have been presented: warning pipe and safe pipe. And a potential-collision-detection method based on two flexible VFs has been proposed. The safe pipe constructs the safe workspace dynamically for the robot, which makes it possible to detect the potential collision between the robot and the obstacles. By calculating the speed and the acceleration of the robot end-effecter (EE), the warning pipe can adjust its radius to detect the deviation from the EE to the reference path. These spatial constraints serve as constraint conditions for constrained robot control. The approach enables multiobstacle manipulation task of telerobot in precise interactive teleoperation environment. We illustrate our approach on a teleoperative manipulation task and analyze the performance results. The performance-comparison experimental results demonstrate that the control mode employing our method can assist the operator more precisely in teleoperative tasks. Due to the properties such as collision avoidance and safety, operators can complete the tasks more efficiently along with reduction in operating tension. PMID:24693252

  17. Flexible sliding seal

    NASA Technical Reports Server (NTRS)

    Wallenhorst, E. L.

    1980-01-01

    Circular seal both slides and flexes to accomodate relative motion between two sealed members. Originally developed for Space Shuttle orbiter, it contains sliding seal to accommodate engine gimbaling and flexible seal that absorbs forward motion at high thrust of engine heat shield relative to airframe. Other possible applications are in support structures of heavy machinery and vehicle engines. Flexible sliding seal is ring about 7 feet in diameter and can withstand temperatures up to 1,600 F.

  18. Experiments in cooperative manipulation: A system perspective

    NASA Technical Reports Server (NTRS)

    Schneider, Stanley A.; Cannon, Robert H., Jr.

    1989-01-01

    In addition to cooperative dynamic control, the system incorporates real time vision feedback, a novel programming technique, and a graphical high level user interface. By focusing on the vertical integration problem, not only these subsystems are examined, but also their interfaces and interactions. The control system implements a multi-level hierarchical structure; the techniques developed for operator input, strategic command, and cooperative dynamic control are presented. At the highest level, a mouse-based graphical user interface allows an operator to direct the activities of the system. Strategic command is provided by a table-driven finite state machine; this methodology provides a powerful yet flexible technique for managing the concurrent system interactions. The dynamic controller implements object impedance control; an extension of Nevill Hogan's impedance control concept to cooperative arm manipulation of a single object. Experimental results are presented, showing the system locating and identifying a moving object catching it, and performing a simple cooperative assembly. Results from dynamic control experiments are also presented, showing the controller's excellent dynamic trajectory tracking performance, while also permitting control of environmental contact force.

  19. Flexible production systems

    NASA Astrophysics Data System (ADS)

    Chudakov, A. D.; Shchetinin, D. D.

    1986-03-01

    Flexible production systems are a technological tool design to automate multiple product line manufacturing. Flexible production systems provide an efficient means of organizing combined equipment operations and bring the production organization nearer to an unmanned arrangement or one requiring a limited number of workers. This is achieved by intensifying and automating manufacturing processes; coordinating the automated processes involved in warehousing and materials transport to maintain a tight production path; and using computers to automate production preparation and production control. The prerequisites for a change to these new production structures include numerical control NC tools and machining centers, power connection points for robots, automated conveying and warehousing systems controlled by microelectronic devices and control computer complexes consisting primarily of microprocessor-based units capable of controlling equipment via a direct connection and on a real-time basis. The types of flexible production systems in operation are divided into three groups: (1) flexible automated lines (GAL), (2) flexible production modules (GPM); and (3) flexible production complexes (GPK).

  20. Plug-n-play microfluidic systems from flexible assembly of glass-based flow-control modules.

    PubMed

    Meng, Zhi-Jun; Wang, Wei; Liang, Xuan; Zheng, Wei-Chao; Deng, Nan-Nan; Xie, Rui; Ju, Xiao-Jie; Liu, Zhuang; Chu, Liang-Yin

    2015-04-21

    In this study, we report on a simple and versatile plug-n-play microfluidic system that is fabricated from flexible assembly of glass-based flow-control modules for flexibly manipulating flows for versatile emulsion generation. The microfluidic system consists of three basic functional units: a flow-control module, a positioning groove, and a connection fastener. The flow-control module that is based on simple assembly of low-cost glass slides, coverslips, and glass capillaries provides excellent chemical resistance and optical properties, and easy wettability modification for flow manipulation. The flexible combination of the flow-control modules with 3D-printed positioning grooves and connection fasteners enables creation of versatile microfluidic systems for generating various higher-order multiple emulsions. The simple and reversible connection of the flow-control modules also allows easy disassembly of the microfluidic systems for further scale-up and functionalization. We demonstrate the scalability and controllability of flow manipulation by creating microfluidic systems from flexible assembly of flow-control modules for controllable generation of multiple emulsions from double emulsions to quadruple emulsions. Meanwhile, the flexible flow manipulation in the flow-control module provides advanced functions for improved control of the drop size, and for controllable generation of drops containing distinct components within multiple emulsions to extend the emulsion structure. Such modular microfluidic systems provide flexibility and versatility to flexibly manipulate micro-flows for enhanced and extended applications. PMID:25711675

  1. Soft, flexible micromanipulators comprising polypyrrole trilayer microactuators

    NASA Astrophysics Data System (ADS)

    Khaldi, Alexandre; Maziz, Ali; Alici, Gursel; Spinks, Geoffrey M.; Jager, Edwin W. H.

    2015-04-01

    Within the areas of cell biology, biomedicine and minimal invasive surgery, there is a need for soft, flexible and dextrous biocompatible manipulators for handling biological objects, such as single cells and tissues. Present day technologies are based on simple suction using micropipettes for grasping objects. The micropipettes lack the possibility of accurate force control, nor are they soft and compliant and may thus cause damage to the cells or tissue. Other micromanipulators use conventional electric motors however the further miniaturization of electrical motors and their associated gear boxes and/or push/pull wires has reached its limits. Therefore there is an urgent need for new technologies for micromanipulation of soft biological matter. We are developing soft, flexible micromanipulators such as micro- tweezers for the handling and manipulation of biological species including cells and surgical tools for minimal invasive surgery. Our aim is to produce tools with minimal dimensions of 100 μm to 1 mm in size, which is 1-2 orders of magnitude smaller than existing technology. We present newly developed patterning and microfabrication methods for polymer microactuators as well as the latest results to integrate these microactuators into easy to use manipulation tools. The outcomes of this study contribute to the realisation of low-foot print devices articulated with electroactive polymer actuators for which the physical interface with the power source has been a significant challenge limiting their application. Here, we present a new bottom-up microfabrication process. We show for the first time that such a bottom-up fabricated actuator performs a movement in air. This is a significant step towards widening the application areas of the soft microactuators.

  2. Flexible quantum circuits using scalable continuous-variable cluster states

    NASA Astrophysics Data System (ADS)

    Alexander, Rafael N.; Menicucci, Nicolas C.

    2016-06-01

    We show that measurement-based quantum computation on scalable continuous-variable (CV) cluster states admits more quantum-circuit flexibility and compactness than similar protocols for standard square-lattice CV cluster states. This advantage is a direct result of the macronode structure of these states—that is, a lattice structure in which each graph node actually consists of several physical modes. These extra modes provide additional measurement degrees of freedom at each graph location, which can be used to manipulate the flow and processing of quantum information more robustly and with additional flexibility that is not available on an ordinary lattice.

  3. Genetic manipulation of francisella tularensis.

    PubMed

    Zogaj, Xhavit; Klose, Karl E

    2010-01-01

    Francisella tularensis is a facultative intracellular pathogen that causes the disease tularemia. F. tularensis subsp. tularensis causes the most severe disease in humans and has been classified as a Category A select agent and potential bioweapon. There is currently no vaccine approved for human use, making genetic manipulation of this organism critical to unraveling the genetic basis of pathogenesis and developing countermeasures against tularemia. The development of genetic techniques applicable to F. tularensis have lagged behind those routinely used for other bacteria, primarily due to lack of research and the restricted nature of the biocontainment required for studying this pathogen. However, in recent years, genetic techniques, such as transposon mutagenesis and targeted gene disruption, have been developed, that have had a dramatic impact on our understanding of the genetic basis of F. tularensis virulence. In this review, we describe some of the methods developed for genetic manipulation of F. tularensis. PMID:21607086

  4. Genetic Manipulation of Francisella Tularensis

    PubMed Central

    Zogaj, Xhavit; Klose, Karl E.

    2011-01-01

    Francisella tularensis is a facultative intracellular pathogen that causes the disease tularemia. F. tularensis subsp. tularensis causes the most severe disease in humans and has been classified as a Category A select agent and potential bioweapon. There is currently no vaccine approved for human use, making genetic manipulation of this organism critical to unraveling the genetic basis of pathogenesis and developing countermeasures against tularemia. The development of genetic techniques applicable to F. tularensis have lagged behind those routinely used for other bacteria, primarily due to lack of research and the restricted nature of the biocontainment required for studying this pathogen. However, in recent years, genetic techniques, such as transposon mutagenesis and targeted gene disruption, have been developed, that have had a dramatic impact on our understanding of the genetic basis of F. tularensis virulence. In this review, we describe some of the methods developed for genetic manipulation of F. tularensis. PMID:21607086

  5. Noncontact Acoustic Manipulation in Air

    NASA Astrophysics Data System (ADS)

    Kozuka, Teruyuki; Yasui, Kyuichi; Tuziuti, Toru; Towata, Atsuya; Iida, Yasuo

    2007-07-01

    A noncontact manipulation technique is useful for micromachine technology, biotechnology, and new materials processing. In this paper, we describe an advanced manipulation technique for transporting small objects in air. A standing wave field was generated by two sound beams crossing each other generated by bolted Langevin transducers. Expanded polystyrene particles were trapped at the nodes of the sound pressure in the standing wave field. The position of a trapped particle was shifted by changing the phase difference between the two sound beams. When the trapped particle is transported, it spatially oscillate periodically in a direction perpendicular to that of particle transportation. The numerical calculation of an acoustic field revealed that it is caused by the reflection of an ultrasonic wave at each transducer surface.

  6. The laboratory telerobotic manipulator program

    NASA Technical Reports Server (NTRS)

    Herndon, J. N.; Babcock, S. M.; Butler, P. L.; Costello, H. M.; Glassell, R. L.; Kress, R. L.; Kuban, D. P.; Rowe, J. C.; Williams, D. M.

    1989-01-01

    New opportunities for the application of telerobotic systems to enhance human intelligence and dexterity in the hazardous environment of space are presented by the NASA Space Station Program. Because of the need for significant increases in extravehicular activity and the potential increase in hazards associated with space programs, emphasis is being heightened on telerobotic systems research and development. The Laboratory Telerobotic Manipulator (LTM) program is performed to develop and demonstrate ground-based telerobotic manipulator system hardware for research and demonstrations aimed at future NASA applications. The LTM incorporates traction drives, modularity, redundant kinematics, and state-of-the-art hierarchical control techniques to form a basis for merging the diverse technological domains of robust, high-dexterity teleoperations and autonomous robotic operation into common hardware to further NASA's research.

  7. Control of robot manipulator compliance

    NASA Technical Reports Server (NTRS)

    Nguyen, Charles C.; Pooran, Farhad J.; Premack, Timothy

    1986-01-01

    Robotic assembly operations such as mating and fastening of parts are more successful if the robot manipulator compliance can be controlled so that various coordinates are free to comply with external constraints. This paper presents the design of a hybrid controller to provide active compliance to a six-degree-of-freedom robot built at NASA/GSFC using force and position feedback. Simulation results of a 2 degree-of-freedom model is presented and discussed.

  8. Attitude control of a space structure using a 3-R rigid manipulator

    NASA Astrophysics Data System (ADS)

    Mukherjee, Ranjan; Zurowski, Mary

    The attitude control of space structures is an important problem. There has been considerable research in this area that has focussed on the use of momentum exchange devices. In this paper, we propose to control the attitude of space structures using a serial three-link PUMA-type manipulator that can be mounted on the space structure. This unconventional method of attitude control exploits the nonholonomic nature of the constraints that arise due to the conservation of angular momentum. We adopt a surface integral approach for the motion planning of the manipulator that will reorient the space structure in any desired way. The salient features of our algorithm are: (a) it is possible to mathematically prove the controllability of the system; (b) The motion of the manipulator can be planned amidst additional constraints like joint limits of the manipulator; and (c) the algorithm can be easily extended for application to flexible space structures.

  9. Detection and manipulation of phosphoinositides☆

    PubMed Central

    Idevall-Hagren, Olof; Camilli, Pietro De

    2016-01-01

    Phosphoinositides (PIs) are minor components of cell membranes, but play key roles in cell function. Recent refinements in techniques for their detection, together with imaging methods to study their distribution and changes, have greatly facilitated the study of these lipids. Such methods have been complemented by the parallel development of techniques for the acute manipulation of their levels, which in turn allow bypassing the long-term adaptive changes implicit in genetic perturbations. Collectively, these advancements have helped elucidate the role of PIs in physiology and the impact of the dysfunction of their metabolism in disease. Combining methods for detection and manipulation enables the identification of specific roles played by each of the PIs and may eventually lead to the complete deconstruction of the PI signaling network. Here, we review current techniques used for the study and manipulation of cellular PIs and also discuss advantages and disadvantages associated with the various methods. This article is part of a Special Issue entitled Phosphoinositides. PMID:25514766

  10. Manipulation of Biofilm Microbial Ecology

    SciTech Connect

    White, D.C.; Palmer, R.J., Jr.; Zinn, M.; Smith, C.A.; Burkhalter, R.; Macnaughton, S.J.; Whitaker, K.W.; Kirkegaard, R.D.

    1998-08-15

    The biofilm mode of growth provides such significant advantages to the members of the consortium that most organisms in important habitats are found in biofilms. The study of factors that allow manipulation of biofilm microbes in the biofilm growth state requires that reproducible biofilms be generated. The most effective monitoring of biofilm formation, succession and desaturation is with on-line monitoring of microbial biofilms with flowcell for direct observation. The biofilm growth state incorporates a second important factor, the heterogeneity in distribution in time and space of the component members of the biofilm consortium. This heterogeneity is reflected not only in the cellular distribution but in the metabolic activity within a population of cells. Activity and cellular distribution can be mapped in four dimensions with confocal microscopy, and function can be ascertained by genetically manipulated reporter functions for specific genes or by vital stains. The methodology for understanding the microbial ecology of biofilms is now much more readily available and the capacity to manipulate biofilms is becoming an important feature of biotechnology.

  11. Flexible transparent electrode

    NASA Astrophysics Data System (ADS)

    Demiryont, Hulya; Shannon, Kenneth C., III; Moorehead, David; Bratcher, Matthew

    2011-06-01

    This paper presents the properties of the EclipseTECTM transparent conductor. EclipseTECTM is a room temperature deposited nanostructured thin film coating system comprised of metal-oxide semiconductor elements. The system possesses metal-like conductivity and glass-like transparency in the visible region. These highly conductive TEC films exhibit high shielding efficiency (35dB at 1 to 100GHz). EclipseTECTM can be deposited on rigid or flexible substrates. For example, EclipseTECTM deposited on polyethylene terephthalate (PET) is extremely flexible that can be rolled around a 9mm diameter cylinder with little or no reduction in electrical conductivity and that can assume pre-extension states after an applied stress is relieved. The TEC is colorless and has been tailored to have high visible transmittance which matches the eye sensitivity curve and allows the viewing of true background colors through the coating. EclipseTECTM is flexible, durable and can be tailored at the interface for applications such as electron- or hole-injecting OLED electrodes as well as electrodes in flexible displays. Tunable work function and optical design flexibility also make EclipseTECTM well-suited as a candidate for grid electrode replacement in next-generation photovoltaic cells.

  12. Printed Microinductors for Flexible Substrates

    NASA Technical Reports Server (NTRS)

    Brandon, Erik; Whitacre, Jay; Wesseling, Emily

    2005-01-01

    A method of fabricating planar, flexible microinductors that exhibit a relatively high quality factor (Q) between 1 and 10 MHz has been devised. These inductors are targeted for use in flexible, low-profile power-converter circuits. They could also be incorporated into electronic circuits integrated into flexible structures, including flexible antenna and solar-sail structures that are deployable.

  13. Dynamics of a flexible extendible beam

    NASA Astrophysics Data System (ADS)

    Stylianou, Marinos Costa

    Axially moving materials arise in problems associated with spacecraft antennas, pipes conveying fluid, and telescopic robotic manipulators. Hamilton's principle is used to derive the governing differential equation of motion and system invariant properties of a flexible extendible beam (FEB) protruding from a rigid wall with prescribed extrusion profile. Numerical solutions are obtained using finite element analysis in which the number of elements is fixed while the sizes of the elements change with time. To this end, a variable domain beam finite element whose size is a prescribed function of time is formulated. The accuracy of this variable domain beam element is demonstrated through the time integration of equations of motion using various extrusion profiles. Additional verification is performed by the evaluation of the system's invariant quantities, comparison with special analytical solution, and the dynamic stability analysis of pipes conveying fluid. The effects of wall flexibility, tip mass, and high frequency axial motion perturbations to the transverse response of the FEB are also examined. The versatility and power of the finite element formulation is demonstrated in a simulation of an extruding FEB which carries a tip mass and protrudes from a flexible envelope beam which imparts three dimensional rigid-body rotations to the system.

  14. Improved Thin, Flexible Heat Pipes

    NASA Technical Reports Server (NTRS)

    Rosenfeld, John H.; Gernert, Nelson J.; Sarraf, David B.; Wollen, Peter J.; Surina, Frank C.; Fale, John E.

    2004-01-01

    Flexible heat pipes of an improved type are fabricated as layers of different materials laminated together into vacuum- tight sheets or tapes. In comparison with prior flexible heat pipes, these flexible heat pipes are less susceptible to leakage. Other advantages of these flexible heat pipes, relative to prior flexible heat pipes, include high reliability and greater ease and lower cost of fabrication. Because these heat pipes are very thin, they are highly flexible. When coated on outside surfaces with adhesives, these flexible heat pipes can be applied, like common adhesive tapes, to the surfaces of heat sinks and objects to be cooled, even if those surfaces are curved.

  15. Spatial selective manipulation of microbubbles by tunable surface acoustic waves

    PubMed Central

    Zhou, Wei; Niu, Lili; Cai, Feiyan; Li, Fei; Wang, Chen; Huang, Xiaowei; Wang, Jingjing; Wu, Junru; Meng, Long; Zheng, Hairong

    2016-01-01

    A microfluidic device based on a pair of slant-finger interdigital transducers (SFITs) is developed to achieve a selective and flexible manipulation of microbubbles (MBs) by surface acoustic waves (SAWs). The resonance frequency of SAWs generated by the SFITs depends on the location of its parallel pathway; the particles at different locations of the SAWs' pathway can be controlled selectively by choosing the frequency of the excitation signal applied on the SFITs. By adjusting the input signal continuously, MBs can be transported along the acoustic aperture precisely. The displacement of MBs has a linear relationship with the frequency shift. The resolution of transportation is 15.19 ± 2.65 μm when the shift of input signal frequency is at a step of 10 kHz. In addition, the MBs can be controlled in a two-dimensional plane by combining variations of the frequency and the relative phase of the excitation signal applied on the SFITs simultaneously. This technology may open up the possibility of selectively and flexibly manipulating MBs using a simple one-dimensional device. PMID:27462381

  16. Spatial selective manipulation of microbubbles by tunable surface acoustic waves.

    PubMed

    Zhou, Wei; Niu, Lili; Cai, Feiyan; Li, Fei; Wang, Chen; Huang, Xiaowei; Wang, Jingjing; Wu, Junru; Meng, Long; Zheng, Hairong

    2016-05-01

    A microfluidic device based on a pair of slant-finger interdigital transducers (SFITs) is developed to achieve a selective and flexible manipulation of microbubbles (MBs) by surface acoustic waves (SAWs). The resonance frequency of SAWs generated by the SFITs depends on the location of its parallel pathway; the particles at different locations of the SAWs' pathway can be controlled selectively by choosing the frequency of the excitation signal applied on the SFITs. By adjusting the input signal continuously, MBs can be transported along the acoustic aperture precisely. The displacement of MBs has a linear relationship with the frequency shift. The resolution of transportation is 15.19 ± 2.65 μm when the shift of input signal frequency is at a step of 10 kHz. In addition, the MBs can be controlled in a two-dimensional plane by combining variations of the frequency and the relative phase of the excitation signal applied on the SFITs simultaneously. This technology may open up the possibility of selectively and flexibly manipulating MBs using a simple one-dimensional device. PMID:27462381

  17. Natural flexible dermal armor.

    PubMed

    Yang, Wen; Chen, Irene H; Gludovatz, Bernd; Zimmermann, Elizabeth A; Ritchie, Robert O; Meyers, Marc A

    2013-01-01

    Fish, reptiles, and mammals can possess flexible dermal armor for protection. Here we seek to find the means by which Nature derives its protection by examining the scales from several fish (Atractosteus spatula, Arapaima gigas, Polypterus senegalus, Morone saxatilis, Cyprinius carpio), and osteoderms from armadillos, alligators, and leatherback turtles. Dermal armor has clearly been developed by convergent evolution in these different species. In general, it has a hierarchical structure with collagen fibers joining more rigid units (scales or osteoderms), thereby increasing flexibility without significantly sacrificing strength, in contrast to rigid monolithic mineral composites. These dermal structures are also multifunctional, with hydrodynamic drag (in fish), coloration for camouflage or intraspecies recognition, temperature and fluid regulation being other important functions. The understanding of such flexible dermal armor is important as it may provide a basis for new synthetic, yet bioinspired, armor materials. PMID:23161399

  18. Flexible and stretchable micromagnet arrays for tunable biointerfacing

    PubMed Central

    Tseng, Peter; Lin, Jonathan; Owsley, Keegan; Kong, Janay; Kunze, Anja; Murray, Coleman

    2015-01-01

    We develop a process to surface pattern PDMS with ferromagnetic structures of varying sizes (micron to mm) and thicknesses (> 70 micron). We utilize their flexibility and magnetic reach to confer dynamic, additive properties to a variety of substrates such as coverslips and eppendorf tubes. We find these substrates can generate additional modes of magnetic droplet manipulation, and can tunably steer magnetic-cell organization. PMID:25537971

  19. Iterative inverse kinematics with manipulator configuration control

    SciTech Connect

    Grudic, G.Z.; Lawrence, P.D.

    1993-08-01

    A new method, termed the offset modification method (OM method), for solving the manipulator inverse kinematics problem is presented. The OM method works by modifying the link offset values of a manipulator until it is possible to derive closed-form inverse kinematics equations for the resulting manipulator (termed the model manipulator). This procedure allows one to derive a set of three nonlinear equations in three unknowns that, when numerically solved, give an inverse kinematics solution for the original manipulator. The OM method can be applied to manipulators with any number of degrees of freedom, as long as the manipulator satisfies a given set of conditions (Theorem 1). The OM method is tested on a 6-degree-of-freedom manipulator that has no known closed-form inverse kinematics equations. It is shown that the OM method is applicable to real-time manipulator control, can be used to guarantee convergence to a desired endpoint position and orientation (if it exists), and allows one to directly choose which inverse kinematics solution the algorithm will converge to (as specified in the model manipulator closed-form inverse kinematics equations). Applications of the method to other 6-DOF manipulator geometries and to redundant manipulators (i.e. greater than 6 DOF geometries) are discussed.

  20. Flexible radiator system

    NASA Technical Reports Server (NTRS)

    Oren, J. A.

    1982-01-01

    The soft tube radiator subsystem is described including applicable system requirements, the design and limitations of the subsystem components, and the panel manufacturing method. The soft tube radiator subsystem is applicable to payloads requiring 1 to 12 kW of heat rejection for orbital lifetimes per mission of 30 days or less. The flexible radiator stowage volume required is about 60% and the system weight is about 40% of an equivalent heat rejection rigid panel. The cost should also be considerably less. The flexible radiator is particularly suited to shuttle orbiter sortie payloads and also whose mission lengths do not exceed the 30 day design life.

  1. Thin flexible intercalation anodes

    SciTech Connect

    Levy, S.C.; Cieslak, W.R.; Klassen, S.E.; Lagasse, R.R.

    1994-10-01

    Poly(acrylonitrile) fibers have been pyrolyzed under various conditions to form flexible carbon yarns capable of intercalating lithium ions. These fibers have also been formed into both woven and non woven cloths. Potentiostatic, potentiodynamic and galvanostatic tests have been conducted with these materials in several electrolytes. In some tests, a potential hold was used after each constant current charge and discharge. These tests have shown some of these flexible materials to reversibly intercalate lithium ions to levels that are suitable for use as a practical battery anode.

  2. Manipulative therapy (Feldenkrais, massage, chiropractic manipulation) for neck pain.

    PubMed

    Plastaras, Christopher; Schran, Seth; Kim, Natasha; Darr, Deborah; Chen, Mary Susan

    2013-07-01

    Neck pain is an extremely common symptom with many possible etiologies. A substantial number of patients are turning to complementary and alternative medicine (CAM). Low-quality evidence supports the beneficial effects of CAM. Feldenkrais, massage therapy, and spinal manipulation are discussed in detail. Complications are generally benign and self-limited, although occasional catastrophic consequences have been documented. Despite the favorable opinion many rheumatologists have of some CAM therapy, many patients are not disclosing CAM use to their medical providers. By expressing interest, asking questions, and taking a shared-decision-making approach, providers can encourage disclosure and provide valuable input. PMID:23666468

  3. Hydraulic manipulator design, analysis, and control at Oak Ridge National Laboratory

    SciTech Connect

    Kress, R.L.; Jansen, J.F.; Love, L.J.; Basher, A.M.H.

    1996-09-01

    To meet the increased payload capacities demanded by present-day tasks, manipulator designers have turned to hydraulics as a means of actuation. Hydraulics have always been the actuator of choice when designing heavy-life construction and mining equipment such as bulldozers, backhoes, and tunneling devices. In order to successfully design, build, and deploy a new hydraulic manipulator (or subsystem) sophisticated modeling, analysis, and control experiments are usually needed. To support the development and deployment of new hydraulic manipulators Oak Ridge National Laboratory (ORNL) has outfitted a significant experimental laboratory and has developed the software capability for research into hydraulic manipulators, hydraulic actuators, hydraulic systems, modeling of hydraulic systems, and hydraulic controls. The hydraulics laboratory at ORNL has three different manipulators. First is a 6-Degree-of-Freedom (6-DoF), multi-planer, teleoperated, flexible controls test bed used for the development of waste tank clean-up manipulator controls, thermal studies, system characterization, and manipulator tracking. Finally, is a human amplifier test bed used for the development of an entire new class of teleoperated systems. To compliment the hardware in the hydraulics laboratory, ORNL has developed a hydraulics simulation capability including a custom package to model the hydraulic systems and manipulators for performance studies and control development. This paper outlines the history of hydraulic manipulator developments at ORNL, describes the hydraulics laboratory, discusses the use of the equipment within the laboratory, and presents some of the initial results from experiments and modeling associated with these hydraulic manipulators. Included are some of the results from the development of the human amplifier/de-amplifier concepts, the characterization of the thermal sensitivity of hydraulic systems, and end-point tracking accuracy studies. Experimental and analytical

  4. Applications of optical manipulation in plant biology

    NASA Astrophysics Data System (ADS)

    Buer, Charles S.

    Measuring small forces in biology is important for determining basic physiological parameters of a cell. The plant cell wall provides a primary defense and presents a barrier to research. Magnitudes of small forces are impossible to measure with mechanical transducers, glass needles, atomic force microscopy, or micropipet-based force transduction due to the cell wall. Therefore, a noninvasive method of breaching the plant cell wall to access the symplastic region of the cell is required. Laser light provides sub-micrometer positioning, particle manipulation without mechanical contact, and piconewton force determination. Consequently, the extension of laser microsurgery to expand an experimental tool for plant biology encompassed the overall objective. A protocol was developed for precisely inserting microscopic objects into the periplasmic region of plant callus cells using laser microsurgery. Ginkgo biloba and Agrobacterium rhizogenes were used as the model system for developing the optical tweezers and scalpel techniques. Better than 95% survival was achieved after plasmolyzing G. biloba cells, ablating a 2-4 μm hole through the cell wall using a pulsed UV laser beam, trapping and manipulating bacteria into the periplasmic region, and deplasmolyzing the cells. Optical trapping experiments implied a difference existed between the bacteria models. Determining the optical trapping efficiency of Agrobacterium rhizogenes and A. tumefaciens strains indicated the A. rhizogenes strain, ATCC 11325, was significantly less efficiently trapped than strains A4 and ATCC 15834 and the A. tumefaciens strain LBA4404. Differences were also found in capsule generation, growth media viscosity, and transmission electron microscopy negative staining implying that a difference in surface structure exists. Calcofluor fluorescence suggests the difference involves an exopolysaccharide. Callus cell plasmolysis revealed Hechtian strands interconnecting the plasma membrane and the cell wall

  5. Experimental Characterization of a Flexible Thermal Slip Sensor

    PubMed Central

    Francomano, Maria Teresa; Accoto, Dino; Guglielmelli, Eugenio

    2012-01-01

    Tactile sensors are needed for effectively controlling the interaction between a robotic hand and the environment, e.g., during manipulation of objects, or for the tactile exploration of unstructured environments, especially when other sensing modalities, such as vision or audition, become ineffective. In the case of hand prostheses, mainly intended for dexterous manipulation of daily living objects, the possibility of quickly detecting slip occurrence, thus avoiding inadvertent falling of the objects, is prodromal to any manipulation task. In this paper we report on a slip sensor with no-moving parts, based on thermo-electrical phenomena, fabricated on a flexible substrate and suitable for integration on curved surfaces, such as robotic finger pads. Experiments performed using a custom made test bench, which is capable of generating controlled slip velocities, show that the sensor detects slip events in less than 50 ms. This response time is short enough for enabling future applications in the field of hand prosthetics. PMID:23202209

  6. Modeling and control for micro and nano manipulation

    NASA Astrophysics Data System (ADS)

    Wejinya, Uchechukwu C.

    Manipulation of micro and nano entities implies the movement of micro and nano entities from an initial position (location) to the desire position (location). This operation is not only necessary, but a required task with great precision. The tools needed for the manipulation needs to be chosen properly because the capabilities of the human hand are very restricted. Smart micro and nano manipulation are becoming of great interest in many applications including medicine and industry. In industry, high precision manipulation systems are especially needed for mass production of both micro and nano systems which consist of different component in respective scales. The transition from assembling and manipulating micro and nano entities manually to mass products with high quality is only attainable by automated assembly and manipulation systems. An example is the testing of integrated circuits which can be carried out by exchanging the manipulation tool by an electric probe. Furthermore, in medical research it is customary to pick up a single cell (human, plant, or animal), and carry it to another device which is used to further analyze the cell. Consequently, the cell of interest has to be separated from the other cells and picked up using the appropriate micro/nano tool. Hence it becomes absolutely necessary that the appropriate tool be used for specific micro or nano entity manipulation and assembly. In this research, we focus on developing micro tool for manipulating micro and nano entities in liquid environment using a micro fluidic end effector system with in-situ Polyvinylidene Fluoride (PVDF) sensing. The microfluidic end effector system consists of a DC micro-diaphragm pump and compressor, one region of flexible latex tube, a Polyvinylidene Fluoride (PVDF) sensor for in-situ measurement of micro drag force, and a micro pipette. The micro pipette of the novel microfluidic end effector system has an internal diameter (ID) smaller than 20mum used for microfluidic

  7. Reconfigurable site-selective manipulation of atomic quantum systems in two-dimensional arrays of dipole traps

    SciTech Connect

    Kruse, J.; Gierl, C.; Schlosser, M.; Birkl, G.

    2010-06-15

    We trap atoms in versatile two-dimensional (2D) arrays of optical potentials, prepare flexible 2D spin configurations, perform site-selective coherent manipulation, and demonstrate the implementation of simultaneous measurements of different system properties, such as dephasing and decoherence. This approach for the flexible manipulation of atomic quantum systems is based on the combination of 2D arrays of microlenses and 2D arrays of liquid crystal light modulators. This offers extended types of control for the investigation of quantum degenerate gases, quantum information processing, and quantum simulations.

  8. The fiber-optic imaging and manipulation of neural activity during animal behavior.

    PubMed

    Miyamoto, Daisuke; Murayama, Masanori

    2016-02-01

    Recent progress with optogenetic probes for imaging and manipulating neural activity has further increased the relevance of fiber-optic systems for neural circuitry research. Optical fibers, which bi-directionally transmit light between separate sites (even at a distance of several meters), can be used for either optical imaging or manipulating neural activity relevant to behavioral circuitry mechanisms. The method's flexibility and the specifications of the light structure are well suited for following the behavior of freely moving animals. Furthermore, thin optical fibers allow researchers to monitor neural activity from not only the cortical surface but also deep brain regions, including the hippocampus and amygdala. Such regions are difficult to target with two-photon microscopes. Optogenetic manipulation of neural activity with an optical fiber has the advantage of being selective for both cell-types and projections as compared to conventional electrophysiological brain tissue stimulation. It is difficult to extract any data regarding changes in neural activity solely from a fiber-optic manipulation device; however, the readout of data is made possible by combining manipulation with electrophysiological recording, or the simultaneous application of optical imaging and manipulation using a bundle-fiber. The present review introduces recent progress in fiber-optic imaging and manipulation methods, while also discussing fiber-optic system designs that are suitable for a given experimental protocol. PMID:26427958

  9. Metamorphic manipulating mechanism design for MCCB using index reduced iteration

    NASA Astrophysics Data System (ADS)

    Xu, Jinghua; Zhang, Shuyou; Zhao, Zhen; Lin, Xiaoxia

    2013-03-01

    The present research on moulded case circuit breaker(MCCB) focuses on the enhancement of current-limiting interrupting performance during short circuit, overload, under voltage and phase failure, involving electrics, magnetic, mechanics, thermal, material, friction, arc extinguishing, impact vibration, skin effect, etc. The rigid-flexible coupling of the parts and components of the metamorphic manipulating mechanism in multi-fields leads to the non-rigid, high frequency, high damping, singularity of the Euler-Lagrange equations which represents the multi-body dynamics. The small step iteration which is used for obtaining the instantaneous and short time critical interrupting performance of metamorphic mechanism appears inaccuracy. It is difficult to realize top-down design by existing CAD systems. Therefore, a metamorphic manipulating mechanism design method for MCCB using index reduced iteration(IRI) is put forward. The metamorphic manipulating mechanism of MCCB is decomposed into three mechanisms: main switch connector mechanism, electromagnet-drawbar-jump buckle mechanism, and bimetallic strip-drawbar mechanism, which is respectively described by electro-dynamic force, electromagnet force, and bimetallic strip force. The dummy part(virtual rigid) without moment of inertia and mass is employed as intermediate to join the flexible body and rigid body. The model of rigid-flexible coupling metamorphic mechanism multi-body dynamics is built. The differential algebraic equations(DAEs) of the multibody dynamics model are converted to pure ordinary differential equations(ODEs) by coordinate partition. Order reduced integration with multi-step and variable step-size is preceded based on IRI. The non-linear algebraic equations are solved in each integration step by Newton-Rapson iteration. There is no ill-condition and singularity of Jacobian matrix when step size reduces to zero. The independent prototype design system using ACIS R13, HOOPS V11.0 and Visual C++.NET 2003

  10. Controlling Flexible Robot Arms Using High Speed Dynamics Process

    NASA Technical Reports Server (NTRS)

    Jain, Abhinandan (Inventor)

    1996-01-01

    A robot manipulator controller for a flexible manipulator arm having plural bodies connected at respective movable hinges and flexible in plural deformation modes corresponding to respective modal spatial influence vectors relating deformations of plural spaced nodes of respective bodies to the plural deformation modes, operates by computing articulated body quantities for each of the bodies from respective modal spatial influence vectors, obtaining specified body forces for each of the bodies, and computing modal deformation accelerations of the nodes and hinge accelerations of the hinges from the specified body forces, from the articulated body quantities and from the modal spatial influence vectors. In one embodiment of the invention, the controller further operates by comparing the accelerations thus computed to desired manipulator motion to determine a motion discrepancy, and correcting the specified body forces so as to reduce the motion discrepancy. The manipulator bodies and hinges are characterized by respective vectors of deformation and hinge configuration variables, and computing modal deformation accelerations and hinge accelerations is carried out for each one of the bodies beginning with the outermost body by computing a residual body force from a residual body force of a previous body and from the vector of deformation and hinge configuration variables, computing a resultant hinge acceleration from the body force, the residual body force and the articulated hinge inertia, and revising the residual body force modal body acceleration.

  11. Optical manipulation for optogenetics: otoliths manipulation in zebrafish (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Favre-Bulle, Itia A.; Scott, Ethan; Rubinsztein-Dunlop, Halina

    2016-03-01

    Otoliths play an important role in Zebrafish in terms of hearing and sense of balance. Many studies have been conducted to understand its structure and function, however the encoding of its movement in the brain remains unknown. Here we developed a noninvasive system capable of manipulating the otolith using optical trapping while we image its behavioral response and brain activity. We'll also present our tools for behavioral response detection and brain activity mapping. Acceleration is sensed through movements of the otoliths in the inner ear. Because experimental manipulations involve movements, electrophysiology and fluorescence microscopy are difficult. As a result, the neural codes underlying acceleration sensation are poorly understood. We have developed a technique for optically trapping otoliths, allowing us to simulate acceleration in stationary larval zebrafish. By applying forces to the otoliths, we can elicit behavioral responses consistent with compensation for perceived acceleration. Since the animal is stationary, we can use calcium imaging in these animals' brains to identify the functional circuits responsible for mediating responses to acceleration in natural settings.

  12. Earth orbital teleoperator manipulator system evaluation program

    NASA Technical Reports Server (NTRS)

    Brye, R. G.; Frederick, P. N.; Kirkpatrick, M., III; Shields, N. L., Jr.

    1977-01-01

    The operator's ability to perform five manipulator tip movements while using monoptic and stereoptic video systems was assessed. Test data obtained were compared with previous results to determine the impact of camera placement and stereoptic viewing on manipulator system performance. The tests were performed using the NASA MSFC extendible stiff arm Manipulator and an analog joystick controller. Two basic manipulator tasks were utilized. The minimum position change test required the operator to move the manipulator arm to touch a target contract. The dexterity test required removal and replacement of pegs.

  13. Failure tolerant operation of kinematically redundant manipulators

    NASA Technical Reports Server (NTRS)

    Lewis, Christopher L.; Maciejewski, Anthony A.

    1994-01-01

    Redundant manipulators may compensate for failed joints with their additional degrees of freedom. In this paper such a manipulator is considered fault tolerant if it can guarantee completion of a task after any one of its joints has failed. This fault tolerance of kinematically redundant manipulators is insured here. Methods to analyze the manipulator's work space find regions inherently suitable for critical tasks because of their high level of failure tolerance. Constraints are then placed on the manipulator's range of motion to guarantee completion of a task.

  14. Methods of manipulating stressed epistructures

    DOEpatents

    Wanlass, Mark W

    2014-04-08

    A method of processing an epistructure or processing a semiconductor device including associating a conformal and flexible handle with the epistructure and removing the epistructure and handle as a unit from the parent substrate. The method further includes causing the epistructure and handle unit to conform to a shape that differs from the shape the epistructure otherwise inherently assumes upon removal from the parent substrate. A device prepared according to the disclosed methods.

  15. Flexible Classroom Furniture

    ERIC Educational Resources Information Center

    Kim Hassell,

    2011-01-01

    Classroom design for the 21st-century learning environment should accommodate a variety of learning skills and needs. The space should be large enough so it can be configured to accommodate a number of learning activities. This also includes furniture that provides flexibility and accommodates collaboration and interactive work among students and…

  16. Designing Flexible Instruction

    ERIC Educational Resources Information Center

    Harris, Clark R.; Kaff, Marilyn S.; Anderson, Mary Jo; Knackendoffel, Ann

    2007-01-01

    Principals and teachers need a framework that will allow school personnel to reach and teach all students within the general education setting. One such framework is universal design for learning (UDL). UDL is achieved by means of flexible curricular materials and activities that provide alternatives for students with disparities in abilities and…

  17. Flexible electronics: Sophisticated skin

    NASA Astrophysics Data System (ADS)

    Bauer, Siegfried

    2013-10-01

    Advances in materials science and layout design have enabled the realization of flexible and multifunctional electronic devices. Two demonstrations of electronic skins, which combine temperature and pressure sensing with integrated thermal actuators and organic displays, unveil the potential of these devices for robotics and clinical applications.

  18. Diversity and Flexibility.

    ERIC Educational Resources Information Center

    Anastasi, Anne

    1990-01-01

    Responds to five major articles by Duckworth, Goldman, Healy, Sampson, and Goodyear on issues pertaining to testing and assessment in counseling psychology. Suggests that such a diversity of approaches leads to a more comprehensive and flexible model of counseling, adaptable to differences in clients, context, and counselor personalities. (TE)

  19. Flexible photovoltaic device

    SciTech Connect

    Berman, E.

    1989-03-28

    A photovoltaic device is described comprising a transparent substrate, a transparent conductive layer adjacent to the transparent substrate, a TFS layer adjacent to the transparent conductive layer, and a conductive layer adjacent to the TFS layer, the transparent substrate being a tetrafluoroethyleneperfluoroalkooxy resin in the form of a flexible film.

  20. Flexible optical panel

    DOEpatents

    Veligdan, James T.

    2001-01-01

    A flexible optical panel includes laminated optical waveguides, each including a ribbon core laminated between cladding, with the core being resilient in the plane of the core for elastically accommodating differential movement thereof to permit winding of the panel in a coil.

  1. ESEA Flexibility. Updated

    ERIC Educational Resources Information Center

    US Department of Education, 2012

    2012-01-01

    In order to move forward with State and local reforms designed to improve academic achievement and increase the quality of instruction for all students in a manner that was not originally contemplated by the No Child Left Behind Act of 2001 (NCLB), a State educational agency (SEA) may request flexibility, on its own behalf and on behalf of its…

  2. Technology for concrete pipe manipulator

    NASA Astrophysics Data System (ADS)

    Li, Bin; Wang, Dan; Lin, Renzhi

    2009-12-01

    The pipe manipulator is a developing mechatronic system to enhance productivity and protects workers from cave-ins in the trench while excavating and laying pipe. The pipe manipulator is for installing concrete pipe into the trench. It is an optical-electro-mechanical system. The mechanism is make up of two parts, the upside and underside. The upside is for lifting the equipment by backhoe and rotating the underside mechanism. It includes rigidity lift beams, holding pad, four-bar linkages, hydraulic cylinder, rotating support, and rotating mechanism. Holding pad will press the bucket back to keep the bucket hooking the pipe man safely and stably. The underside mechanism is for lifting, holding and adjusting the pipe section's stance. The underside mechanism includes support trolley, and lift fork. The support trolley is driven by hydraulic cylinder for moving the fork forward or backward while laying a pipe into trench. The fork is with a self-lock mechanism for preventing the pipe from slide out of the prongs. A new photoelectric locating system is developed for auto-measuring the installing pipe section's stance within the work area. The laser target has been developed as a key part in the photoelectric locating systems. The photoelectric target is a rotating polar coordinate. Photodiodes are used for making the polar radius. There is an angular displacement sensor sitting on the heart-axis of the target for measuring angle of the target rotating. The pipe manipulator can be located by the system, and the locating methods have been presented at last of the paper.

  3. Technology for concrete pipe manipulator

    NASA Astrophysics Data System (ADS)

    Li, Bin; Wang, Dan; Lin, Renzhi

    2010-01-01

    The pipe manipulator is a developing mechatronic system to enhance productivity and protects workers from cave-ins in the trench while excavating and laying pipe. The pipe manipulator is for installing concrete pipe into the trench. It is an optical-electro-mechanical system. The mechanism is make up of two parts, the upside and underside. The upside is for lifting the equipment by backhoe and rotating the underside mechanism. It includes rigidity lift beams, holding pad, four-bar linkages, hydraulic cylinder, rotating support, and rotating mechanism. Holding pad will press the bucket back to keep the bucket hooking the pipe man safely and stably. The underside mechanism is for lifting, holding and adjusting the pipe section's stance. The underside mechanism includes support trolley, and lift fork. The support trolley is driven by hydraulic cylinder for moving the fork forward or backward while laying a pipe into trench. The fork is with a self-lock mechanism for preventing the pipe from slide out of the prongs. A new photoelectric locating system is developed for auto-measuring the installing pipe section's stance within the work area. The laser target has been developed as a key part in the photoelectric locating systems. The photoelectric target is a rotating polar coordinate. Photodiodes are used for making the polar radius. There is an angular displacement sensor sitting on the heart-axis of the target for measuring angle of the target rotating. The pipe manipulator can be located by the system, and the locating methods have been presented at last of the paper.

  4. Spin-manipulating polarized deuterons

    SciTech Connect

    Morozov, V S; Krisch, A D; Leonova, M A; Raymond, R S; Sivers, D W; Wong, V K; Hinterberger, F; Kondratenko, A M; Stephenson, E J

    2011-03-01

    Spin dynamics of polarized deuteron beams near depolarization resonances, including a new polarization preservation concept based on specially-designed multiple resonance crossings, has been tested in a series of experiments in the COSY synchrotron. Intricate spin dynamics with sophisticated pre-programmed patterns as well as effects of multiple crossings of a resonance were studied both theoretically and experimentally with excellent agreement. Possible applications of these results to preserve, manipulate and spin-flip polarized beams in synchrotrons and storage rings are discussed.

  5. Determination of joint drives for stable end-effector motion in flexible robotic systems

    NASA Technical Reports Server (NTRS)

    Ider, Sitki Kemal

    1989-01-01

    The prescribed tasks in high speed robotic systems are severely deteriorated because of their manipulator dynamic deflections. On the other hand conventional dynamic modeling techniques fail to reveal appropriate control forces in flexible systems. The conventional dynamic equations of motion for systems subject to kinematical constraints are modified by a new concept of control force representation. The directions of the control forces are selected such that they correspond to the joint degrees of freedom. Then the joint control forces and torques that yield unperturbed prescribed motions are solved simultaneously with the system motion. A flexible manipulator is presented to illustrate the methods proposed.

  6. The Integration of an Electro-hydraulic Manipulator Arm into a Self-contained Mobile Delivery System

    SciTech Connect

    Borland, Mark Wilson; Berry, Stephen Michael

    1999-04-01

    The Portable Articulated Arm Deployment System (PAADS) is a remotely controlled vehicle for delivering a tele-operated electro-hydraulic manipulator arm to a field deployable location. The self-contained system includes a boom vehicle with long reach capability, an electro-hydraulic manipulator arm, closed circuit television (CCTV) systems, and onboard tools. On board power systems consist of a self contained, propane fired 8 KW generator and an air compressor for pneumatic tools. The generator provides the power to run the air compressor as well as provide power to operate the 110 VAC auxiliary lighting system for the video cameras. The separate control console can be located up to 500 ft from the vehicle. PAADS is a fully integrated system, containing all equipment required to perform complex field operations. Hydraulic integration of the manipulator arm into the vehicle hydraulic drive system was necessary to eliminate the tether management of hoses, which extended vehicle operating range, minimized hydraulic pressure losses, and provided the opportunity to go to a radio frequency (RF) control system in the future, thereby eliminating the control cable. This paper presents the key decision points during system development. Emphasis is placed on ease of operator control and not on an intelligent machine approach. In addition, emphasis is placed on the philosophy of remote operation based on sound principles on integration.

  7. The Integration of an Electro-Hydraulic Manipulator Arm into a Self-Contained Mobile Delivery System

    SciTech Connect

    M. Borland; S. M. Berry

    1999-04-01

    The Portable Articulated Arm Deployment System (PAADS) is a remotely controlled vehicle for delivering a tele-operated electro-hydraulic manipulator arm to a field-deployable location. The self-contained system includes a boom vehicle with long reach capability, an electro-hydraulic manipulator arm, closed circuit television (CCTV) systems, and onboard tools. On board power systems consist of a self-contained, propane-fired 8-KW generator and an air compressor for pneumatic tools. The generator provides the power to run the air compressor as well as power to operate the 110-VAC auxiliary lighting system for the video cameras. The separate control console can be located up to 500 ft from the vehicle. PAADS is a fully integrated system, containing all equipment required to perform complex field operations. Hydraulic integration of the manipulator arm into the vehicle hydraulic drive system was necessary to eliminate the tether management of hoses, which extended vehicle operating range, minimized hydraulic pressure losses, and provided the opportunity to go to a radio frequency (RF) control system in the future, thereby eliminating the control cable. This paper presents the key decision points during system development. Emphasis is placed on ease of operator control and not on an intelligent machine approach. In addition, emphasis is placed on the philosophy of remote operation based on sound principles of integration.

  8. Tumor Stroma Manipulation By MSC.

    PubMed

    Grisendi, Giulia; Spano, Carlotta; Rossignoli, Filippo; D Souza, Naomi; Golinelli, Giulia; Fiori, Agnese; Horwitz, Edwin M; Guarneri, Valentina; Piacentini, Federico; Paolucci, Paolo; Dominici, Massimo

    2016-01-01

    Tumor stroma (TS) plays relevant roles in all steps of cancer development. We here address several fundamental aspects related with the interaction between cancer cells and their stromal counterparts. Dissecting these players is of pivotal importance to understand oncogenesis, immunoescape and drug resistance. In addition, this better comprehension will allow the introduction of novel and more effective therapeutic approaches where manipulated stromal elements may become detrimental for tumor growth. Our group and others rely on the use of multipotent mesenchymal stromal/stem cells (MSC) as anti-cancer tools, since these putative TS cell precursors can deliver potent apoptosis-inducing agents. Multimodal-armed MSC can target a variety of cancers in vitro and, when injected in vivo, they localize into tumors mediating cell death without evident toxicities to normal tissues. While several aspects of these strategies shall require further investigations, these approaches collectively indicate how TS manipulation by MSC represents a tool to influence the fate of cancer cells, creating a new generation of anti-cancer strategies. PMID:26953248

  9. Manipulating expression of tonoplast transporters.

    PubMed

    Li, Zhigang; Zhou, Man; Hu, Qian; Reighard, Shane; Yuan, Shuangrong; Yuan, Ning; San, Bekir; Li, Dayong; Jia, Haiyan; Luo, Hong

    2012-01-01

    Plant vacuoles have multifaceted roles including turgor maintenance, cytosolic pH and ionic homeostasis, plant protection against environmental stress, detoxification, pigmentation, and cellular signaling. These roles are achieved through the coordinated activities of many proteins in the tonoplast (vacuolar membrane), of which the proton pumps and ion transporters have been modified for improved abiotic stress tolerance in transgenic plants. Here we describe a method to manipulate vacuolar H(+)-pyrophosphatase in turfgrass and evaluate the impact of the modified tonoplast on the phenotype, biochemistry, and physiology of the transgenics. Creeping bentgrass (Agrostis stolonifera L.) plants overexpressing an Arabidopsis vacuolar H(+)-pyrophosphatase AVP1 exhibited improved growth and enhanced salt tolerance, likely associated with increased photosynthesis, relative water content, proline production, and Na(+) uptake. These transgenic plants also had decreased solute leakage in the leaf tissues and increased concentrations of Na(+), K(+), Cl(-), and total phosphorus in the root tissues. Similar strategies can be employed to manipulate other tonoplast transporters and in other plant species to produce transgenic plants with improved performance under various abiotic stresses. PMID:22895772

  10. Actuators for a space manipulator

    NASA Technical Reports Server (NTRS)

    Chun, W.; Brunson, P.

    1987-01-01

    The robotic manipulator can be decomposed into distinct subsytems. One particular area of interest of mechanical subsystems is electromechanical actuators (or drives). A drive is defined as a motor with an appropriate transmission. An overview is given of existing, as well as state-of-the-art drive systems. The scope is limited to space applications. A design philosophy and adequate requirements are the initial steps in designing a space-qualified actuator. The focus is on the d-c motor in conjunction with several types of transmissions (harmonic, tendon, traction, and gear systems). The various transmissions will be evaluated and key performance parameters will be addressed in detail. Included in the assessment is a shuttle RMS joint and a MSFC drive of the Prototype Manipulator Arm. Compound joints are also investigated. Space imposes a set of requirements for designing a high-performance drive assembly. Its inaccessibility and cryogenic conditions warrant special considerations. Some guidelines concerning these conditions are present. The goal is to gain a better understanding in designing a space actuator.

  11. Mobile remote manipulator vehicle system

    NASA Technical Reports Server (NTRS)

    Bush, Harold G. (Inventor); Mikulas, Martin M., Jr. (Inventor); Wallsom, Richard E. (Inventor); Jensen, J. Kermit (Inventor)

    1987-01-01

    A mobile remote manipulator system is disclosed for assembly, repair and logistics transport on, around and about a space station square bay truss structure. The vehicle is supported by a square track arrangement supported by guide pins integral with the space station truss structure and located at each truss node. Propulsion is provided by a central push-pull drive mechanism that extends out from the vehicle one full structural bay over the truss and locks drive rods into the guide pins. The draw bar is now retracted and the mobile remote manipulator system is pulled onto the next adjacent structural bay. Thus, translation of the vehicle is inchworm style. The drive bar can be locked onto two guide pins while the extendable draw bar is within the vehicle and then push the vehicle away one bay providing bidirectional push-pull drive. The track switches allow the vehicle to travel in two orthogonal directions over the truss structure which coupled with the bidirectional drive, allow movement in four directions on one plane. The top layer of this trilayered vehicle is a logistics platform. This platform is capable of 369 degees of rotation and will have two astronaut foot restraint platforms and a space crane integral.

  12. Optical proximity sensors for manipulators

    NASA Technical Reports Server (NTRS)

    Johnson, A. R.

    1973-01-01

    A breadboard optical proximity sensor intended for application to remotely operated manipulators has been constructed and evaluated in the laboratory. The sensing head was 20 mm x 15 mm x 10 mm in size, and could be made considerably smaller. Several such devices could be conveniently mounted on a manipulator hand, for example, to align the hand with an object. Type 1 and Type 2 optical configurations are discussed, Type 1 having a sharply defined sensitive volume, Type 2 an extended one. The sensitive volume can be placed at any distance between 1 cm and approximately 1 m by choice of a replaceable prism. The Type 1 lateral resolution was 0.5 mm on one axis and 5 mm perpendicular to it for a unit focused at 7.5 cm. The corresponding resolution in the axial direction was 2.4 cm, but improvement to 0.5 cm is possible. The effect of surface reflectivity is discussed and possible modes of application are suggested.

  13. Semantics of directly manipulating spatializations.

    PubMed

    Hu, Xinran; Bradel, Lauren; Maiti, Dipayan; House, Leanna; North, Chris; Leman, Scotland

    2013-12-01

    When high-dimensional data is visualized in a 2D plane by using parametric projection algorithms, users may wish to manipulate the layout of the data points to better reflect their domain knowledge or to explore alternative structures. However, few users are well-versed in the algorithms behind the visualizations, making parameter tweaking more of a guessing game than a series of decisive interactions. Translating user interactions into algorithmic input is a key component of Visual to Parametric Interaction (V2PI) [13]. Instead of adjusting parameters, users directly move data points on the screen, which then updates the underlying statistical model. However, we have found that some data points that are not moved by the user are just as important in the interactions as the data points that are moved. Users frequently move some data points with respect to some other 'unmoved' data points that they consider as spatially contextual. However, in current V2PI interactions, these points are not explicitly identified when directly manipulating the moved points. We design a richer set of interactions that makes this context more explicit, and a new algorithm and sophisticated weighting scheme that incorporates the importance of these unmoved data points into V2PI. PMID:24051771

  14. Nanoscale logic operation in optically manipulated micro-droplets

    NASA Astrophysics Data System (ADS)

    Ogura, Yusuke; Nishimura, Takahiro; Tanida, Jun

    2010-08-01

    Logic gates consisting of DNA molecules are useful for direct processing of information that relates to biomolecules including DNA at nanoscale. This study is aimed at demonstrating operation of the DNA logic gates by optical manipulation of micro-droplets that contain DNA to show potential of photonics techniques in realizing nanoscale computing. Connections of different DNA logic gates are reconfigurable owing to flexibility in manipulating the micro-droplets. The method is effective in, for example, implementing logic operations in limited-volumes at multiple positions in parallel, enhancing an operation rate, and decreasing sample consumption, and it can be a promising technique applicable to photonic DNA computing. We used a two-input and one-output AND or OR gate consisting of DNA in experiments. The individual inputs, A and B, were encoded into different DNA molecules, I1 and I2, and the output was obtained from a fluorescence signal. Input A (B) is 1 when DNA I1 (I2) exists, and 0 when the DNA does not exist. Microdroplets were made by mixing DNA solution, acetophenone as solvent, and sorbitan monooleate as surfactant. For AND/OR operation, two micro-droplets, one of which contained input-DNAs and the other contained AND/OR logic gates, were optically manipulated to be in contact each other; then the micro-droplets coalesced and the operation started. Experimental results show that expected fluorescence intensities are obtained as the output for all possible input values, and logic operation can be implemented successfully in optically manipulated microdroplets.

  15. FSD- FLEXIBLE SPACECRAFT DYNAMICS

    NASA Technical Reports Server (NTRS)

    Fedor, J. V.

    1994-01-01

    The Flexible Spacecraft Dynamics and Control program (FSD) was developed to aid in the simulation of a large class of flexible and rigid spacecraft. FSD is extremely versatile and can be used in attitude dynamics and control analysis as well as in-orbit support of deployment and control of spacecraft. FSD has been used to analyze the in-orbit attitude performance and antenna deployment of the RAE and IMP class satellites, and the HAWKEYE, SCATHA, EXOS-B, and Dynamics Explorer flight programs. FSD is applicable to inertially-oriented spinning, earth oriented, or gravity gradient stabilized spacecraft. The spacecraft flexibility is treated in a continuous manner (instead of finite element) by employing a series of shape functions for the flexible elements. Torsion, bending, and three flexible modes can be simulated for every flexible element. FSD can handle up to ten tubular elements in an arbitrary orientation. FSD is appropriate for studies involving the active control of pointed instruments, with options for digital PID (proportional, integral, derivative) error feedback controllers and control actuators such as thrusters and momentum wheels. The input to FSD is in four parts: 1) Orbit Construction FSD calculates a Keplerian orbit with environmental effects such as drag, magnetic torque, solar pressure, thermal effects, and thruster adjustments; or the user can supply a GTDS format orbit tape for a particular satellite/time-span; 2) Control words - for options such as gravity gradient effects, control torques, and integration ranges; 3) Mathematical descriptions of spacecraft, appendages, and control systems- including element geometry, properties, attitudes, libration damping, tip mass inertia, thermal expansion, magnetic tracking, and gimbal simulation options; and 4) Desired state variables to output, i.e., geometries, bending moments, fast Fourier transform plots, gimbal rotation, filter vectors, etc. All FSD input is of free format, namelist construction. FSD

  16. Neural Correlates of Attentional Flexibility during Approach and Avoidance Motivation

    PubMed Central

    Calcott, Rebecca D.; Berkman, Elliot T.

    2015-01-01

    Dynamic, momentary approach or avoidance motivational states have downstream effects on eventual goal success and overall well being, but there is still uncertainty about how those states affect the proximal neurocognitive processes (e.g., attention) that mediate the longer-term effects. Attentional flexibility, or the ability to switch between different attentional foci, is one such neurocognitive process that influences outcomes in the long run. The present study examined how approach and avoidance motivational states affect the neural processes involved in attentional flexibility using fMRI with the aim of determining whether flexibility operates via different neural mechanisms under these different states. Attentional flexibility was operationalized as subjects’ ability to switch between global and local stimulus features. In addition to subjects’ motivational state, the task context was manipulated by varying the ratio of global to local trials in a block in light of recent findings about the moderating role of context on motivation-related differences in attentional flexibility. The neural processes involved in attentional flexibility differ under approach versus avoidance states. First, differences in the preparatory activity in key brain regions suggested that subjects’ preparedness to switch was influenced by motivational state (anterior insula) and the interaction between motivation and context (superior temporal gyrus, inferior parietal lobule). Additionally, we observed motivation-related differences the anterior cingulate cortex during switching. These results provide initial evidence that motivation-induced behavioral changes may arise via different mechanisms in approach versus avoidance motivational states. PMID:26000735

  17. Autonomous manipulation on a robot: Summary of manipulator software functions

    NASA Technical Reports Server (NTRS)

    Lewis, R. A.

    1974-01-01

    A six degree-of-freedom computer-controlled manipulator is examined, and the relationships between the arm's joint variables and 3-space are derived. Arm trajectories using sequences of third-degree polynomials to describe the time history of each joint variable are presented and two approaches to the avoidance of obstacles are given. The equations of motion for the arm are derived and then decomposed into time-dependent factors and time-independent coefficients. Several new and simplifying relationships among the coefficients are proven. Two sample trajectories are analyzed in detail for purposes of determining the most important contributions to total force in order that relatively simple approximations to the equations of motion can be used.

  18. Implementation of a robotic flexible assembly system

    NASA Technical Reports Server (NTRS)

    Benton, Ronald C.

    1987-01-01

    As part of the Intelligent Task Automation program, a team developed enabling technologies for programmable, sensory controlled manipulation in unstructured environments. These technologies include 2-D/3-D vision sensing and understanding, force sensing and high speed force control, 2.5-D vision alignment and control, and multiple processor architectures. The subsequent design of a flexible, programmable, sensor controlled robotic assembly system for small electromechanical devices is described using these technologies and ongoing implementation and integration efforts. Using vision, the system picks parts dumped randomly in a tray. Using vision and force control, it performs high speed part mating, in-process monitoring/verification of expected results and autonomous recovery from some errors. It is programmed off line with semiautomatic action planning.

  19. Research on reconfigurable and reliable manipulators: Final report, August 14, 1994--August 14, 1996

    SciTech Connect

    Khosla, P.K.; Kanade, Takeo

    1996-12-31

    To address the need for a more flexible and reliable manipulator, the authors propose the concept of a rapidly deployable fault tolerant manipulator system. Such a system combines a Reconfigurable Modular Manipulator System (RMMS) with support software for rapid programming, trajectory planning, and control. This allows the user to rapidly configure a fault tolerant manipulator custom-tailored for a given task. This thesis investigates all aspects involved in such a system. It describes an RMMS prototype which consists of seven manipulator modules with a total of four degrees-of-freedom. The reconfigurability of the hardware is made transparent to the user by the supporting control software that automatically adapts itself to the current manipulator configuration. To achieve high reliability, a global fault tolerant trajectory planning algorithm is introduced. This algorithm guarantees that a manipulator can continue its task even when one of the manipulator joints fails and is immobilized. Finally, all these aspects are considered simultaneously in the task based design software, that determines the manipulator configuration, its base position, and the fault tolerant joint space trajectory that are optimally suited to perform a given task. The most important contribution of this thesis is a novel agent-based approach to solve the task based design problem. The approach is based on a genetic algorithm for which the modification and evaluation operations are implemented as autonomous asynchronous agents. Finally, the thesis presents a performance analysis of the agent-based design framework by comparing its results with those of exhaustive search, random search, and multiple restart statistical hill-climbing.

  20. Flexible cryogenic conduit

    DOEpatents

    Brindza, Paul Daniel; Wines, Robin Renee; Takacs, James Joseph

    1999-01-01

    A flexible and relatively low cost cryogenic conduit is described. The flexible cryogenic conduit of the present invention comprises a first inner corrugated tube with single braided serving, a second outer corrugated tube with single braided serving concentric with the inner corrugated tube, and arranged outwardly about the periphery of the inner corrugated tube and between the inner and outer corrugated tubes: a superinsulation layer; a one half lap layer of polyester ribbon; a one half lap layer of copper ribbon; a spirally wound refrigeration tube; a second one half lap layer of copper ribbon; a second one half lap layer of polyester ribbon; a second superinsulation layer; a third one half lap layer of polyester ribbon; and a spirally wound stretchable and compressible filament.

  1. Flexible rotor dynamics analysis

    NASA Technical Reports Server (NTRS)

    Shen, F. A.

    1973-01-01

    A digital computer program was developed to analyze the general nonaxisymmetric and nonsynchronous transient and steady-state rotor dynamic performance of a bending- and shear-wise flexible rotor-bearing system under various operating conditions. The effects of rotor material mechanical hysteresis, rotor torsion flexibility, transverse effects of rotor axial and torsional loading and the anisotropic, in-phase and out-of-phase bearing stiffness and damping force and moment coefficients were included in the program to broaden its capability. An optimum solution method was found and incorporated in the computer program. Computer simulation of experimental data was made and qualitative agreements observed. The mathematical formulations, computer program verification, test data simulation, and user instruction was presented and discussed.

  2. Flexible spacecraft simulator

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Verification of control algorithms for flexible spacecraft can be done only through simulation and test; these are necessary to understand control/structure interaction (C/SI) sufficiently to design robust controllers for future spacecraft. The objective persued is to develop a low-cost facility which simulates the fundamental problem of C/SI; and to provide accessibility for designs so that experience can be gained in applying various multivariable control design methods to an actual structure. A test facility is being constructed with test elements that provide 3 rigid body and 6 flexible modes, all in the horizontal plane, with frequencies below 2.5 Hz. The control force actuator are on/off air jets with sensing by optical displacement sensors. Loop closure is provided by a digital computer with control algorithms designed using the IAC and MATRIX-X.

  3. Flexible cryogenic conduit

    SciTech Connect

    Brindza, P.D.; Wines, R.R.; Takacs, J.J.

    1999-12-21

    A flexible and relatively low cost cryogenic conduit is described. The flexible cryogenic conduit of the present invention comprises a first inner corrugated tube with single braided serving, a second outer corrugated tube with single braided serving concentric with the inner corrugated tube, and arranged outwardly about the periphery of the inner corrugated tube and between the inner and outer corrugated tubes: a superinsulation layer; a one half lap layer of polyester ribbon; a one half lap layer of copper ribbon; a spirally wound refrigeration tube; a second one half lap layer of copper ribbon; a second one half lap layer of polyester ribbon; a second superinsulation layer; a third one half lap layer of polyester ribbon; and a spirally wound stretchable and compressible filament.

  4. Control of flexible structures

    NASA Technical Reports Server (NTRS)

    Russell, R. A.

    1985-01-01

    The requirements for future space missions indicate that many of these spacecraft will be large, flexible, and in some applications, require precision geometries. A technology program that addresses the issues associated with the structure/control interactions for these classes of spacecraft is discussed. The goal of the NASA control of flexible structures technology program is to generate a technology data base that will provide the designer with options and approaches to achieve spacecraft performance such as maintaining geometry and/or suppressing undesired spacecraft dynamics. This technology program will define the appropriate combination of analysis, ground testing, and flight testing required to validate the structural/controls analysis and design tools. This work was motivated by a recognition that large minimum weight space structures will be required for many future missions. The tools necessary to support such design included: (1) improved structural analysis; (2) modern control theory; (3) advanced modeling techniques; (4) system identification; and (5) the integration of structures and controls.

  5. FLEXIBLE GEIGER COUNTER

    DOEpatents

    Richter, H.G.; Gillespie, A.S. Jr.

    1963-11-12

    A flexible Geiger counter constructed from materials composed of vinyl chloride polymerized with plasticizers or co-polymers is presented. The counter can be made either by attaching short segments of corrugated plastic sleeving together, or by starting with a length of vacuum cleaner hose composed of the above materials. The anode is maintained substantially axial Within the sleeving or hose during tube flexing by means of polystyrene spacer disks or an easily assembled polyethylene flexible cage assembly. The cathode is a wire spiraled on the outside of the counter. The sleeving or hose is fitted with glass end-pieces or any other good insulator to maintain the anode wire taut and to admit a counting gas mixture into the counter. Having the cathode wire on the outside of the counter substantially eliminates the objectional sheath effect of prior counters and permits counting rates up to 300,000 counts per minute. (AEC)

  6. PTFE films with improved flexibility

    NASA Technical Reports Server (NTRS)

    Muraca, R. F.; Koch, A. A.

    1972-01-01

    Development and application of flexible polytetrafluroethylene films for expulsion bladders in spacecraft propellant tanks are described. Flexibility of material is obtained by reducing crystallinity through annealing and quenching in water. Physical and mechanical properties of material are presented.

  7. Industrial Fuel Flexibility Workshop

    SciTech Connect

    none,

    2006-09-01

    On September 28, 2006, in Washington, DC, ITP and Booz Allen Hamilton conducted a fuel flexibility workshop with attendance from various stakeholder groups. Workshop participants included representatives from the petrochemical, refining, food and beverage, steel and metals, pulp and paper, cement and glass manufacturing industries; as well as representatives from industrial boiler manufacturers, technology providers, energy and waste service providers, the federal government and national laboratories, and developers and financiers.

  8. Flexible multiply towpreg

    NASA Technical Reports Server (NTRS)

    Muzzy, John D. (Inventor); Varughese, Babu (Inventor)

    1992-01-01

    This invention relates to an improved flexible towpreg and a method of production therefor. The improved flexible towpreg comprises a plurality of towpreg plies which comprise reinforcing filaments and matrix forming material; the reinforcing filaments being substantially wetout by the matrix forming material such that the towpreg plies are substantially void-free composite articles, and the towpreg plies having an average thickness less than about 100 microns. The method of production for the improved flexible towpreg comprises the steps of spreading the reinforcing filaments to expose individually substantially all of the reinforcing filaments; coating the reinforcing filaments with the matrix forming material in a manner causing interfacial adhesion of the matrix forming material to the reinforcing filaments; forming the towpreg plies by heating the matrix forming material contacting the reinforcing filaments until the matrix forming material liquifies and coats the reinforcing filaments; and cooling the towpreg plies in a manner such that substantial cohesion between neighboring towpreg plies is prevented until the matrix forming material solidifies.

  9. Flexible materials technology

    NASA Technical Reports Server (NTRS)

    Steurer, W. H.

    1980-01-01

    A survey of all presently defined or proposed large space systems indicated an ever increasing demand for flexible components and materials, primarily as a result of the widening disparity between the stowage space of launch vehicles and the size of advanced systems. Typical flexible components and material requirements were identified on the basis of recurrence and/or functional commonality. This was followed by the evaluation of candidate materials and the search for material capabilities which promise to satisfy the postulated requirements. Particular attention was placed on thin films, and on the requirements of deployable antennas. The assessment of the performance of specific materials was based primarily on the failure mode, derived from a detailed failure analysis. In view of extensive on going work on thermal and environmental degradation effects, prime emphasis was placed on the assessment of the performance loss by meteoroid damage. Quantitative data were generated for tension members and antenna reflector materials. A methodology was developed for the representation of the overall materials performance as related to systems service life. A number of promising new concepts for flexible materials were identified.

  10. Flexible Multi-Shock Shield

    NASA Technical Reports Server (NTRS)

    Christiansen, Eric L. (Inventor); Crews, Jeanne L. (Inventor)

    2005-01-01

    Flexible multi-shock shield system and method are disclosed for defending against hypervelocity particles. The flexible multi-shock shield system and method may include a number of flexible bumpers or shield layers spaced apart by one or more resilient support layers, all of which may be encapsulated in a protective cover. Fasteners associated with the protective cover allow the flexible multi-shock shield to be secured to the surface of a structure to be protected.

  11. Remote Manipulator System (RMS)-based Controls-Structures Interaction (CSI) flight experiment feasibility study

    NASA Technical Reports Server (NTRS)

    Demeo, Martha E.

    1990-01-01

    The feasibility of an experiment which will provide an on-orbit validation of Controls-Structures Interaction (CSI) technology, was investigated. The experiment will demonstrate the on-orbit characterization and flexible-body control of large flexible structure dynamics using the shuttle Remote Manipulator System (RMS) with an attached payload as a test article. By utilizing existing hardware as well as establishing integration, operation and safety algorithms, techniques and procedures, the experiment will minimize the costs and risks of implementing a flight experiment. The experiment will also offer spin-off enhancement to both the Shuttle RMS (SRMS) and the Space Station RMS (SSRMS).

  12. Incretin manipulation in diabetes management

    PubMed Central

    Pappachan, Joseph M; Raveendran, AV; Sriraman, Rajagopalan

    2015-01-01

    Incretin-based therapies have revolutionized the medical management of type 2 diabetes mellitus (T2DM) in the 21st century. Glucagon-like peptide-1 (GLP-1) suppresses appetite and gastric motility, and has trophic effects on pancreas, cardio-protective and renal effects. GLP-1 analogues and dipeptidyl peptidase-4 inhibitors form the incretin-based therapies. Significant reduction of hemoglobin A1c when used as monotherapy and in combination regimens, favorable effects on body weight, and low risk of hypoglycemia are their unique therapeutic benefits. Their safety and tolerability are comparable to other anti-diabetic medications. Concern about elevated risk of pancreatitis has been discarded by two recent meta-analyses. This article discusses the therapeutic manipulation of incretin system for the management of T2DM. PMID:26131320

  13. Incretin manipulation in diabetes management.

    PubMed

    Pappachan, Joseph M; Raveendran, A V; Sriraman, Rajagopalan

    2015-06-25

    Incretin-based therapies have revolutionized the medical management of type 2 diabetes mellitus (T2DM) in the 21(st) century. Glucagon-like peptide-1 (GLP-1) suppresses appetite and gastric motility, and has trophic effects on pancreas, cardio-protective and renal effects. GLP-1 analogues and dipeptidyl peptidase-4 inhibitors form the incretin-based therapies. Significant reduction of hemoglobin A1c when used as monotherapy and in combination regimens, favorable effects on body weight, and low risk of hypoglycemia are their unique therapeutic benefits. Their safety and tolerability are comparable to other anti-diabetic medications. Concern about elevated risk of pancreatitis has been discarded by two recent meta-analyses. This article discusses the therapeutic manipulation of incretin system for the management of T2DM. PMID:26131320

  14. Genetic Manipulation of Stenotrophomonas maltophilia

    PubMed Central

    Welker, Elliott; Domfeh, Yayra; Tyagi, Deepti; Sinha, Sanjivni; Fisher, Nathan

    2015-01-01

    Stenotrophomonas maltophilia is a Gram-negative, aerobic, motile, environmental bacterium that is emerging as an important nosocomial pathogen (Brooke, 2012; Looney, Narita, & Mühlemann, 2009) with high rates of attributable mortality in severely ill patients (Falagas et al., 2009; Paez & Costa, 2008; Sattler, Mason, & Kaplan, 2000; Senol, DesJardin, Stark, Barefoot, & Snydman, 2002; Weber et al., 2007). S. maltophilia is of particular concern to patients suffering from cystic fibrosis (CF) as it has been shown to colonize airway epithelial and establish a chronic infection (Goncalves-Vidigal et al., 2011). Here we describe several molecular techniques for the genetic manipulation of this bacterium, including DNA extraction, RNA extraction, conjugation of plasmids from E. coli and allelic exchange. PMID:26344220

  15. Genetic manipulation of Porphyromonas gingivalis.

    PubMed

    Bélanger, Myriam; Rodrigues, Paulo; Progulske-Fox, Ann

    2007-06-01

    Porphyromonas gingivalis, an oral anaerobic bacterium, is an important etiological agent of periodontal disease and may contribute to cardiovascular disease, preterm birth, and diabetes as well. Therefore, genetic studies are of crucial importance in investigating molecular mechanisms of P. gingivalis virulence. Although molecular genetic tools have been available for many bacterial species for some time, genetic manipulations of Porphyromonas species were not developed until more recently and remain limited. In this unit, current molecular genetic approaches for mutant construction in P. gingivalis using the suicide vector pPR-UF1 and the transposon Tn4351 are described, as are protocols for performing electroporation and conjugation. Furthermore, a technique to restore the wild-type phenotype of the mutant by complementation using vector pT-COW is provided. Finally, a description of a noninvasive reporter system allowing the study of gene expression and regulation in P. gingivalis completes this unit. PMID:18770611

  16. Manipulating crystallization with molecular additives.

    PubMed

    Shtukenberg, Alexander G; Lee, Stephanie S; Kahr, Bart; Ward, Michael D

    2014-01-01

    Given the importance of organic crystals in a wide range of industrial applications, the chemistry, biology, materials science, and chemical engineering communities have focused considerable attention on developing methods to control crystal structure, size, shape, and orientation. Tailored additives have been used to control crystallization to great effect, presumably by selectively binding to particular crystallographic surfaces and sites. However, substantial knowledge gaps still exist in the fundamental mechanisms that govern the formation and growth of organic crystals in both the absence and presence of additives. In this review, we highlight research discoveries that reveal the role of additives, either introduced by design or present adventitiously, on various stages of formation and growth of organic crystals, including nucleation, dislocation spiral growth mechanisms, growth inhibition, and nonclassical crystal morphologies. The insights from these investigations and others of their kind are likely to guide the development of innovative methods to manipulate crystallization for a wide range of materials and applications. PMID:24579880

  17. Controlling multiple manipulators using RIPS

    NASA Technical Reports Server (NTRS)

    Wang, Yulun; Jordan, Steve; Mangaser, Amante; Butner, Steve

    1989-01-01

    A prototype of the RIPS architecture (Robotic Instruction Processing System) was developed. A two arm robot control experiment is underway to characterize the architecture as well as research multi-arm control. This experiment uses two manipulators to cooperatively position an object. The location of the object is specified by the host computer's mouse. Consequently, real time kinematics and dynamics are necessary. The RIPS architecture is specialized so that it can satisfy these real time constraints. The two arm experimental set-up is discussed. A major part of this work is the continued development of a good programming environment for RIPS. The C++ language is employed and favorable results exist in the targeting of this language to the RIPS hardware.

  18. Current Issues in Flexibility Fitness.

    ERIC Educational Resources Information Center

    Knudson, Duane V.; Magnusson, Peter; McHugh, Malachy

    2000-01-01

    Physical activity is extremely important in maintaining good health. Activity is not possible without a certain amount of flexibility. This report discusses issues related to flexibility fitness. Flexibility is a property of the musculoskeletal system that determines the range of motion achievable without injury to the joints. Static flexibility…

  19. Flexible Scheduling: Making the Transition

    ERIC Educational Resources Information Center

    Creighton, Peggy Milam

    2008-01-01

    Citing literature that supports the benefits of flexible scheduling on student achievement, the author exhorts readers to campaign for flexible scheduling in their library media centers. She suggests tips drawn from the work of Graziano (2002), McGregor (2006) and Stripling (1997) for making a smooth transition from fixed to flexible scheduling:…

  20. Bracing micro/macro manipulators control

    SciTech Connect

    Lew, J.Y.; Book, W.J.

    1994-05-01

    This paper proposes a bracing strategy for micro/macro manipulators. The bracing micro/macro manipulator can provide advantages in accurate positioning, large work-space, and contact-task capability however, in exchange for improvement in performance one must accept the complex control problem along wit the complex dynamics. This research develops a control scheme for a bracing manipulator which makes multiple contacts with the environment. Experimental results show the feasibility of the proposed ideas for real world applications.

  1. Seismic qualification of existing safety class manipulators

    SciTech Connect

    Wu, Ting-shu; Moran, T.J.

    1992-05-01

    There are two bridge type electromechanical manipulators within a nuclear fuel handling facility which were constructed over twenty-five years ago. At that time, there were only minimal seismic considerations. These manipulators together with the facility are being reactivated. Detailed analyses have shown that the manipulators will satisfy the requirements of ANSI/AISC N690-1984 when they are subjected to loadings including the site specific design basis earthquake. 4 refs.

  2. Seismic qualification of existing safety class manipulators

    SciTech Connect

    Wu, Ting-shu; Moran, T.J.

    1992-01-01

    There are two bridge type electromechanical manipulators within a nuclear fuel handling facility which were constructed over twenty-five years ago. At that time, there were only minimal seismic considerations. These manipulators together with the facility are being reactivated. Detailed analyses have shown that the manipulators will satisfy the requirements of ANSI/AISC N690-1984 when they are subjected to loadings including the site specific design basis earthquake. 4 refs.

  3. Algorithmic formulation of control problems in manipulation

    NASA Technical Reports Server (NTRS)

    Bejczy, A. K.

    1975-01-01

    The basic characteristics of manipulator control algorithms are discussed. The state of the art in the development of manipulator control algorithms is briefly reviewed. Different end-point control techniques are described together with control algorithms which operate on external sensor (imaging, proximity, tactile, and torque/force) signals in realtime. Manipulator control development at JPL is briefly described and illustrated with several figures. The JPL work pays special attention to the front or operator input end of the control algorithms.

  4. Spatial-Operator Algebra For Robotic Manipulators

    NASA Technical Reports Server (NTRS)

    Rodriguez, Guillermo; Kreutz, Kenneth K.; Milman, Mark H.

    1991-01-01

    Report discusses spatial-operator algebra developed in recent studies of mathematical modeling, control, and design of trajectories of robotic manipulators. Provides succinct representation of mathematically complicated interactions among multiple joints and links of manipulator, thereby relieving analyst of most of tedium of detailed algebraic manipulations. Presents analytical formulation of spatial-operator algebra, describes some specific applications, summarizes current research, and discusses implementation of spatial-operator algebra in the Ada programming language.

  5. Research on reconfigurable and reliable manipulators

    SciTech Connect

    Khosla, P.K.; Kanade, T.

    1993-01-01

    We have proposed the concept of reconfigurable manipulators as a solution to tasks that require varied configurations of manipulators. Using modules of varying sizes and performance specifications, it is possible to build manipulators to suit the task at hand. Our research is not only addressing the issue of creating such manipulators but also the interesting theoretical challenges posed in mapping tasks to manipulators. We have developed strategies that allow us to determine the kinematic and dynamic configuration of a non-redundant manipulator from task specifications such as reachability, obstacle avoidance, manipulability, joint, limits, and joint velocities and accelerations. We are presently extending this design methodology for design of redundant and fault tolerant manipulator systems. Further, we are also addressing issues in automatic generation of software for kinematics, dynamics, and controllers for the configured manipulators. During the next year, we will be demonstrating automatic generation of software on the prototype system that we are building. We expect to have 4 joint and link modules available for this demonstration. The joint and link modules will also incorporate concepts for making power and data connections when the mechanical connection is made. Further, they will also include electronics, housed within the module, for communication and real-time control.

  6. Research on reconfigurable and reliable manipulators

    NASA Astrophysics Data System (ADS)

    Khosla, P. K.; Kanade, T.

    We have proposed the concept of reconfigurable manipulators as a solution to tasks that require varied configurations of manipulators. Using modules of varying sizes and performance specifications, it is possible to build manipulators to suit the task at hand. Our research is not only addressing the issue of creating such manipulators but also the interesting theoretical challenges posed in mapping tasks to manipulators. We have developed strategies that allow us to determine the kinematic and dynamic configuration of a non-redundant manipulator from task specifications such as reachability, obstacle avoidance, manipulability, joint, limits, and joint velocities and accelerations. We are presently extending this design methodology for design of redundant and fault tolerant manipulator systems. Further, we are also addressing issues in automatic generation of software for kinematics, dynamics, and controllers for the configured manipulators. During the next year, we will be demonstrating automatic generation of software on the prototype system that we are building. We expect to have 4 joint and link modules available for this demonstration. The joint and link modules will also incorporate concepts for making power and data connections when the mechanical connection is made. Further, they will also include electronics, housed within the module, for communication and real-time control.

  7. Culture and Manipulation of Embryonic Cells

    PubMed Central

    Edgar, Lois G.; Goldstein, Bob

    2012-01-01

    The direct manipulation of embryonic cells is an important tool for addressing key questions in cell and developmental biology. C. elegans is relatively unique among genetic model systems in being amenable to manipulation of embryonic cells. Embryonic cell manipulation has allowed the identification of cell interactions by direct means, and it has been an important technique for dissecting mechanisms by which cell fates are specified, cell divisions are oriented, and morphogenesis is accomplished. Here, we present detailed methods for isolating, manipulating and culturing embryonic cells of C. elegans. PMID:22226523

  8. Social Manipulation of Online Recommender Systems

    NASA Astrophysics Data System (ADS)

    Lang, Juan; Spear, Matt; Wu, S. Felix

    Online recommender systems are a common target of attack. Existing research has focused on automated manipulation of recommender systems through the creation of shill accounts, and either do not consider attacks by coalitions of real users, downplay the impact of such attacks, or state that such attacks are difficult to impossible to detect. In this study, we examine a recommender system that is part of an online social network, show that users successfully induced other users to manipulate their recommendations, that these manipulations were effective, and that most such manipulations are detectable even when performed by ordinary, non-automated users.

  9. Silvabase: A flexible data file management system

    NASA Technical Reports Server (NTRS)

    Lambing, Steven J.; Reynolds, Sandra J.

    1991-01-01

    The need for a more flexible and efficient data file management system for mission planning in the Mission Operations Laboratory (EO) at MSFC has spawned the development of Silvabase. Silvabase is a new data file structure based on a B+ tree data structure. This data organization allows for efficient forward and backward sequential reads, random searches, and appends to existing data. It also provides random insertions and deletions with reasonable efficiency, utilization of storage space well but not at the expense of speed, and performance of these functions on a large volume of data. Mission planners required that some data be keyed and manipulated in ways not found in a commercial product. Mission planning software is currently being converted to use Silvabase in the Spacelab and Space Station Mission Planning Systems. Silvabase runs on a Digital Equipment Corporation's popular VAX/VMS computers in VAX Fortran. Silvabase has unique features involving time histories and intervals such as in operations research. Because of its flexibility and unique capabilities, Silvabase could be used in almost any government or commercial application that requires efficient reads, searches, and appends in medium to large amounts of almost any kind of data.

  10. Active coloration with flexible high contrast metastructures

    NASA Astrophysics Data System (ADS)

    Zhu, Li; Kapraun, Jonas; Ferrara, James; Chang-Hasnain, Connie J.

    2015-02-01

    The ability to actively control the perceived color of objects is highly desirable for a variety of applications, such as camouflage, sensing, and displays. Such a phenomenon can be readily found in nature - the chameleon is an excellent example. However, the capability to change color at-will has yet to be reproduced by humans. Ultra-thin dielectric high contrast metastructures (HCMs) have been shown to exhibit unique versatility to manipulate light. In this work, we report a completely new flexible HCM structure whose color can be varied by stretching the membrane. This is accomplished with a novel HCM design that annihilates the 0th order diffraction in a grating while enhancing the -1st order. The color perception of the HCM, determined by the -1st diffraction order, is thus easily changed with the variation of its period. The ultra-thin HCM is patterned on a silicon-on-insulator wafer and transferred onto a flexible membrane. We measure more than 15 times stronger intensity in the -1st order diffraction than the 0th order, in excellent agreement with theoretical results. We experimentally demonstrate brilliant colors and change the color of a 1 cm×1 cm sample from green to orange (39 nm wavelength change) with a stretch of 4.9% (25 nm period change). The same effect can be used for steering a laser beam. We demonstrate more than 40 resolvable beam spots.

  11. Kinematics and Control of Robot Manipulators

    NASA Astrophysics Data System (ADS)

    Paden, Bradley Evan

    This dissertation focuses on the kinematics and control of robot manipulators. The contribution to kinematics is a fundamental theorem on the design of manipulators with six revolute joints. The theorem states, roughly speaking, that manipulators which have six revolute joints and are modeled after the human arm are optimal and essentially unique. In developing the mathematical framework to prove this theorem, we define precisely the notions of length of a manipulator, well-connected-workspace, and work-volume. We contribute to control a set of analysis techniques for the design of variable structure (sliding mode) controllers for manipulators. The organization of the dissertation is the following. After introductory remarks in chapter one, the group of proper rigid motions, G, is introduced in chapter two. The tangent bundle of G is introduced and it is shown that the velocity of a rigid body can be represented by an element in the Lie algebra of G (commonly called a twist). Further, rigid motions which are exponentials of twists are used to describe four commonly occurring subproblems in robot kinematics. In chapter three, the exponentials of twists are used to write the forward kinematic map of robot manipulators and the subproblems of chapter two are used to solve the Stanford manipulator and an elbow manipulator. Chapter four focuses on manipulator singularities. Twist coordinates are used to find critical points of the forward kinematic map. The contribution to kinematics is contained in chapter five where a mathematical framework for studying the relationship between the design of 6R manipulators and their performance is developed. Chapter seven contains the contribution to control. The work of A. F. Filippov on differential equations with discontinuous right-hand-side and the work of F. H. Clarke on generalized gradients are combined to obtain a calculus for analyzing nonsmooth gradient systems. The techniques developed are applied to design a simple

  12. Rotating flexible drag mill

    DOEpatents

    Pepper, W.B.

    1984-05-09

    A rotating parachute for decelerating objects travelling through atmosphere at subsonic or supersonic deployment speeds includes a circular canopy having a plurality of circumferentially arranged flexible panels projecting radially from a solid central disk. A slot extends radially between adjacent panels to the outer periphery of the canopy. Upon deployment, the solid disk diverts air radially to rapidly inflate the panels into a position of maximum diameter. Air impinging on the panels adjacent the panel slots rotates the parachute during its descent. Centrifugal force flattens the canopy into a constant maximum diameter during terminal descent for maximum drag and deceleration.

  13. Composite Flexible Blanket Insulation

    NASA Technical Reports Server (NTRS)

    Kourtides, Demetrius A. (Inventor); Pitts, William C. (Inventor); Goldstein, Howard E. (Inventor); Sawko, Paul M. (Inventor)

    1991-01-01

    Composite flexible multilayer insulation systems (MLI) were evaluated for thermal performance and compared with the currently used fibrous silica (baseline) insulation system. The systems described are multilayer insulations consisting of alternating layers of metal foil and scrim ceramic cloth or vacuum metallized polymeric films quilted together using ceramic thread. A silicon carbide thread for use in the quilting and the method of making it are also described. These systems are useful in providing lightweight insulation for a variety of uses, particularly on the surface of aerospace vehicles subject to very high temperatures during flight.

  14. A flexible business focus

    SciTech Connect

    Hennagir, T.

    1994-11-01

    The challenge of sourcing equipment to meet customer needs around the world remains a prerequisite for boiler and CFB manufacturers as they strive to maintain a strong business presence in key markets. Boiler vendors are learning to meet their targets based upon what the market is, not what they hope it will become. An elastic equipment supply strategy is bolstering new business activity for internationally active boiler and circulating fluidized bed combustion (CFB) vendors. Techniques such as flexible sourcing and expanded scope capability are helping suppliers gain market advantage in new global growth areas.

  15. Flexible composite radiation detector

    DOEpatents

    Cooke, D. Wayne; Bennett, Bryan L.; Muenchausen, Ross E.; Wrobleski, Debra A.; Orler, Edward B.

    2006-12-05

    A flexible composite scintillator was prepared by mixing fast, bright, dense rare-earth doped powdered oxyorthosilicate (such as LSO:Ce, LSO:Sm, and GSO:Ce) scintillator with a polymer binder. The binder is transparent to the scintillator emission. The composite is seamless and can be made large and in a wide variety of shapes. Importantly, the composite can be tailored to emit light in a spectral region that matches the optimum response of photomultipliers (about 400 nanometers) or photodiodes (about 600 nanometers), which maximizes the overall detector efficiency.

  16. Flexible Volumetric Structure

    NASA Technical Reports Server (NTRS)

    Cagle, Christopher M. (Inventor); Schlecht, Robin W. (Inventor)

    2014-01-01

    A flexible volumetric structure has a first spring that defines a three-dimensional volume and includes a serpentine structure elongatable and compressible along a length thereof. A second spring is coupled to at least one outboard edge region of the first spring. The second spring is a sheet-like structure capable of elongation along an in-plane dimension thereof. The second spring is oriented such that its in-plane dimension is aligned with the length of the first spring's serpentine structure.

  17. Flexible Material Systems Testing

    NASA Technical Reports Server (NTRS)

    Lin, John K.; Shook, Lauren S.; Ware, Joanne S.; Welch, Joseph V.

    2010-01-01

    An experimental program has been undertaken to better characterize the stress-strain characteristics of flexible material systems to support a NASA ground test program for inflatable decelerator material technology. A goal of the current study is to investigate experimental methods for the characterization of coated woven material stiffness. This type of experimental mechanics data would eventually be used to define the material inputs of fluid-structure interaction simulation models. The test methodologies chosen for this stress-strain characterization are presented along with the experimental results.

  18. Antegrade Flexible Ureteroscopy for Bilateral Ureteral Stones in a Patient with Severe Hip Joint Ankylosis

    PubMed Central

    Kim, Bum Soo; Lee, Jun Nyung; Choi, Jae Young; Park, Yoon Kyu

    2010-01-01

    In the past several decades there has been a remarkable development of small-caliber, flexible ureteroscopes and various ancillary instruments for stone manipulation and retrieval. Percutaneous antegrade ureteroscopy can be substituted in select cases for retrograde ureteroscopy. We report a case of a 60-year-old man with severe ankylosis in both hip joints who was diagnosed with bilateral ureteral stones. The patient underwent antegrade flexible ureteroscopy and laser lithotripsy. This case illustrates the role of antegrade flexible ureteroscopy combined with the holmium:YAG laser as a minimally invasive, safe, and effective technique for the management of stones in a patient who cannot undergo a retrograde approach. PMID:21165203

  19. Structural vibration control of micro/macro-manipulator using feedforward and feedback approaches

    SciTech Connect

    Lew, J.Y.; Cannon, D.W.; Magee, D.P.; Book, W.J.

    1995-09-01

    Pacific Northwest Laboratory (PDL) researchers investigated the combined use of two control approaches to minimize micro/macro-manipulator structural vibration: (1) modified input shaping and (2) inertial force active damping control. Modified input shaping (MIS) is used as a feedforward controller to modify reference input by canceling the vibratory motion. Inertial force active damping (IFAD) is applied as a feedback controller to increase the system damping and robustness to unexpected disturbances. Researchers implemented both control schemes in the PNL micro/macro flexible-link manipulator testbed collaborating with Georgia Institute of Technology. The experiments successfully demonstrated the effectiveness of two control approaches in reducing structural vibration. Based on the results of the experiments, the combined use of two controllers is recommended for a micro/macro manipulator to achieve the fastest response to commands while canceling disturbances from unexpected forces.

  20. Design, modeling and control of a pneumatically actuated manipulator inspired by biological continuum structures.

    PubMed

    Kang, Rongjie; Branson, David T; Zheng, Tianjiang; Guglielmino, Emanuele; Caldwell, Darwin G

    2013-09-01

    Biological tentacles, such as octopus arms, have entirely flexible structures and virtually infinite degrees of freedom (DOF) that allow for elongation, shortening and bending at any point along the arm length. The amazing dexterity of biological tentacles has driven the growing implementation of continuum manipulators in robotic systems. This paper presents a pneumatic manipulator inspired by biological continuum structures in some of their key features and functions, such as continuum morphology, intrinsic compliance and stereotyped motions with hyper redundant DOF. The kinematics and dynamics of the manipulator are formulated and identified, and a hierarchical controller taking inspiration from the structure of an octopus nervous system is used to relate desired stereotyped motions to individual actuator inputs. Simulations and experiments are carried out to validate the model and prototype where good agreement was found between the two. PMID:23851387

  1. A discrete-time adaptive control scheme for robot manipulators

    NASA Technical Reports Server (NTRS)

    Tarokh, M.

    1990-01-01

    A discrete-time model reference adaptive control scheme is developed for trajectory tracking of robot manipulators. The scheme utilizes feedback, feedforward, and auxiliary signals, obtained from joint angle measurement through simple expressions. Hyperstability theory is utilized to derive the adaptation laws for the controller gain matrices. It is shown that trajectory tracking is achieved despite gross robot parameter variation and uncertainties. The method offers considerable design flexibility and enables the designer to improve the performance of the control system by adjusting free design parameters. The discrete-time adaptation algorithm is extremely simple and is therefore suitable for real-time implementation. Simulations and experimental results are given to demonstrate the performance of the scheme.

  2. Robotic tentacles with three-dimensional mobility based on flexible elastomers.

    PubMed

    Martinez, Ramses V; Branch, Jamie L; Fish, Carina R; Jin, Lihua; Shepherd, Robert F; Nunes, Rui M D; Suo, Zhigang; Whitesides, George M

    2013-01-11

    Soft robotic tentacles that move in three dimensions upon pressurization are fabricated by composing flexible elastomers with different tensile strengths using soft lithographic molding. These actuators are able to grip complex shapes and manipulate delicate objects. Embedding functional components into these actuators (for example, a needle for delivering fluid, a video camera, and a suction cup) extends their capabilities. PMID:22961655

  3. Controlling flexible robot arms using a high speed dynamics process

    NASA Technical Reports Server (NTRS)

    Jain, Abhinandan (Inventor); Rodriguez, Guillermo (Inventor)

    1992-01-01

    Described here is a robot controller for a flexible manipulator arm having plural bodies connected at respective movable hinges, and flexible in plural deformation modes. It is operated by computing articulated body qualities for each of the bodies from the respective modal spatial influence vectors, obtaining specified body forces for each of the bodies, and computing modal deformation accelerations of the nodes and hinge accelerations of the hinges from the specified body forces, from the articulated body quantities and from the modal spatial influence vectors. In one embodiment of the invention, the controller further operates by comparing the accelerations thus computed to desired manipulator motion to determine a motion discrepancy, and correcting the specified body forces so as to reduce the motion discrepancy. The manipulator bodies and hinges are characterized by respective vectors of deformation and hinge configuration variables. Computing modal deformation accelerations and hinge accelerations is carried out for each of the bodies, beginning with the outermost body by computing a residual body force from a residual body force of a previous body, computing a resultant hinge acceleration from the body force, and then, for each one of the bodies beginning with the innermost body, computing a modal body acceleration from a modal body acceleration of a previous body, computing a modal deformation acceleration and hinge acceleration from the resulting hinge acceleration and from the modal body acceleration.

  4. The Stealth Curriculum: Manipulating America's History Teachers

    ERIC Educational Resources Information Center

    Stotsky, Sandra

    2004-01-01

    The purpose of this report is: (1) To point out the features of a number of manipulative supplemental resources for history and social studies teachers; and (2) to show how similarly manipulative professional development workshops propagate the distorted content and recommended teaching practices of such materials to teachers and their…

  5. Welding torch and wire feed manipulator

    NASA Technical Reports Server (NTRS)

    Williams, R. T.

    1967-01-01

    Welding torch and wire feed manipulator increase capability for performing automatic welding operations. The manipulator rotates on its horizontal axis to avoid obstacles as they approach the torch. The initial individual attitudes of the torch and wire guide are set with respect to the general configuration of the part.

  6. Teachers' Beliefs and Teaching Mathematics with Manipulatives

    ERIC Educational Resources Information Center

    Golafshani, Nahid

    2013-01-01

    To promote the implementation of manipulatives into mathematics instruction, this research project examined how the instructional practices of four Grade 9 applied mathematics teachers related to their beliefs about the use of manipulatives in teaching mathematics, its effects on students' learning, and enabling and disabling factors. Teacher…

  7. Count on It: Congruent Manipulative Displays

    ERIC Educational Resources Information Center

    Morin, Joe; Samelson, Vicki M.

    2015-01-01

    Representations that create informative visual displays are powerful tools for communicating mathematical concepts. The National Council of Teachers of Mathematics encourages the use of manipulatives (NCTM 2000). Manipulative materials are often used to present initial representations of basic numerical principles to young children, and it is…

  8. Flexible ocean upwelling pipe

    DOEpatents

    Person, Abraham

    1980-01-01

    In an ocean thermal energy conversion facility, a cold water riser pipe is releasably supported at its upper end by the hull of the floating facility. The pipe is substantially vertical and has its lower end far below the hull above the ocean floor. The pipe is defined essentially entirely of a material which has a modulus of elasticity substantially less than that of steel, e.g., high density polyethylene, so that the pipe is flexible and compliant to rather than resistant to applied bending moments. The position of the lower end of the pipe relative to the hull is stabilized by a weight suspended below the lower end of the pipe on a flexible line. The pipe, apart from the weight, is positively buoyant. If support of the upper end of the pipe is released, the pipe sinks to the ocean floor, but is not damaged as the length of the line between the pipe and the weight is sufficient to allow the buoyant pipe to come to a stop within the line length after the weight contacts the ocean floor, and thereafter to float submerged above the ocean floor while moored to the ocean floor by the weight. The upper end of the pipe, while supported by the hull, communicates to a sump in the hull in which the water level is maintained below the ambient water level. The sump volume is sufficient to keep the pipe full during heaving of the hull, thereby preventing collapse of the pipe.

  9. Asymmetric Flexible Supercapacitor Stack

    PubMed Central

    2008-01-01

    Electrical double layer supercapacitor is very significant in the field of electrical energy storage which can be the solution for the current revolution in the electronic devices like mobile phones, camera flashes which needs flexible and miniaturized energy storage device with all non-aqueous components. The multiwalled carbon nanotubes (MWNTs) have been synthesized by catalytic chemical vapor deposition technique over hydrogen decrepitated Mischmetal (Mm) based AB3alloy hydride. The polymer dispersed MWNTs have been obtained by insitu polymerization and the metal oxide/MWNTs were synthesized by sol-gel method. Morphological characterizations of polymer dispersed MWNTs have been carried out using scanning electron microscopy (SEM), transmission electron microscopy (TEM and HRTEM). An assymetric double supercapacitor stack has been fabricated using polymer/MWNTs and metal oxide/MWNTs coated over flexible carbon fabric as electrodes and nafion®membrane as a solid electrolyte. Electrochemical performance of the supercapacitor stack has been investigated using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy.

  10. Anthropomorphic teleoperation: Controlling remote manipulators with the DataGlove

    NASA Technical Reports Server (NTRS)

    Hale, J. P., II

    1992-01-01

    A two phase effort was conducted to assess the capabilities and limitations of the DataGlove, a lightweight glove input device that can output signals in real-time based on hand shape, orientation, and movement. The first phase was a period for system integration, checkout, and familiarization in a virtual environment. The second phase was a formal experiment using the DataGlove as input device to control the protoflight manipulator arm (PFMA) - a large telerobotic arm with an 8-ft reach. The first phase was used to explore and understand how the DataGlove functions in a virtual environment, build a virtual PFMA, and consider and select a reasonable teleoperation control methodology. Twelve volunteers (six males and six females) participated in a 2 x 3 (x 2) full-factorial formal experiment using the DataGlove to control the PFMA in a simple retraction, slewing, and insertion task. Two within-subjects variables, time delay (0, 1, and 2 seconds) and PFMA wrist flexibility (rigid/flexible), were manipulated. Gender served as a blocking variable. A main effect of time delay was found for slewing and total task times. Correlations among questionnaire responses, and between questionnaire responses and session mean scores and gender were computed. The experimental data were also compared with data collected in another study that used a six degree-of-freedom handcontroller to control the PFMA in the same task. It was concluded that the DataGlove is a legitimate teleoperations input device that provides a natural, intuitive user interface. From an operational point of view, it compares favorably with other 'standard' telerobotic input devices and should be considered in future trades in teleoperation systems' designs.

  11. Use of commercial manipulator to handle a nuclear weapon component

    SciTech Connect

    Baker, C.P.

    1994-08-01

    Pacific Northwest Laboratory (PNL) has developed a manipulator workcell to load and unload nuclear weapon pit assemblies from a cart. To develop this workcell, PNL procured a commercially available manipulator, equipped it with force-sensing and vision equipment, and developed manipulator control software. Manipulator workcell development demonstrated that commercially available manipulator systems can successfully perform this task if the appropriate manipulator is selected and the manipulator workcell tooling and software are carefully designed.

  12. Manipulating duckweed through genome duplication.

    PubMed

    Vunsh, R; Heinig, U; Malitsky, S; Aharoni, A; Avidov, A; Lerner, A; Edelman, M

    2015-01-01

    Significant inter- and intraspecific genetic variation exists in duckweed, thus the potential for genome plasticity and manipulation is high. Polyploidy is recognised as a major mechanism of adaptation and speciation in plants. We produced several genome-duplicated lines of Landoltia punctata (Spirodela oligorrhiza) from both whole plants and regenerating explants using a colchicine-based cocktail. These lines stably maintained an enlarged frond and root morphology. DNA ploidy levels determined by florescence-activated cell sorting indicated genome duplication. Line A4 was analysed after 75 biomass doublings. Frond area, fresh and dry weights, rhizoid number and length were significantly increased versus wild type, while the growth rate was unchanged. This resulted in accumulation of biomass 17-20% faster in the A4 plants. We sought to determine if specific differences in gene products are found in the genome duplicated lines. Non-targeted ultra performance LC-quadrupole time of flight mass spectrometry was employed to compare some of the lines and the wild type to seek identification of up-regulated metabolites. We putatively identified differential metabolites in Line A65 as caffeoyl hexoses. The combination of directed genome duplication and metabolic profiling might offer a path for producing stable gene expression, leading to altered production of secondary metabolites. PMID:25040392

  13. Manipulating resource allocation in plants.

    PubMed

    Bennett, Emma; Roberts, Jeremy A; Wagstaff, Carol

    2012-05-01

    The distribution of nutrients and assimilates in different organs and tissues is in a constant state of flux throughout the growth and development of a plant. At key stages during the life cycle profound changes occur, and perhaps one of the most critical of these is during seed filling. By restricting the competition for reserves in Arabidopsis plants, the ability to manipulate seed size, seed weight, or seed content has been explored. Removal of secondary inflorescences and lateral branches resulted in a stimulation of elongation of the primary inflorescence and an increase in the distance between siliques. The pruning treatment also led to the development of longer and larger siliques that contained fewer, bigger seeds. This seems to be a consequence of a reduction in the number of ovules that develop and an increase in the fatty acid content of the seeds that mature. The data show that shoot architecture could have a substantial impact on the partitioning of reserves between vegetative and reproductive tissues and could be an important trait for selection in rapid phenotyping screens to optimize crop performance. PMID:22291133

  14. Coanda-assisted Spray Manipulation

    NASA Astrophysics Data System (ADS)

    Mabey, Katie; Smith, Barton; Archibald, Reid; West, Brian

    2009-11-01

    An overview of research on a flow control technique called Coanda-assisted Spray Manipulation (CSM) is presented. CSM uses a high-momentum control jet under the influence of the Coanda effect to vector a high volume-flow jet or spray. Actuators provide the capability of moving the location of applied control flow making rotary or arbitrary motion of the vectored flow possible. The presented work includes a fundamental isothermal study on the effects of rotation speed and Reynolds number on a vectored jet using a belt-driven CSM actuator. Three-component velocity data were acquired for three Reynolds numbers and three rotation speeds using timed resolved high-speed stereo Particle Image Velocimetry. A second CSM system with 16 pneumatically-driven control ports has been retrofitted to a flame spray gun. This combination provides the capability to rapidly alter the direction of applied metal powders. High speed video of this process will also be presented. Finally, a fundamental study on the pneumatic system's response to minor losses and connection lines of varying lengths is presented.

  15. Parallel Grid Manipulations in Earth Science Calculations

    NASA Technical Reports Server (NTRS)

    Sawyer, W.; Lucchesi, R.; daSilva, A.; Takacs, L. L.

    1999-01-01

    The National Aeronautics and Space Administration (NASA) Data Assimilation Office (DAO) at the Goddard Space Flight Center is moving its data assimilation system to massively parallel computing platforms. This parallel implementation of GEOS DAS will be used in the DAO's normal activities, which include reanalysis of data, and operational support for flight missions. Key components of GEOS DAS, including the gridpoint-based general circulation model and a data analysis system, are currently being parallelized. The parallelization of GEOS DAS is also one of the HPCC Grand Challenge Projects. The GEOS-DAS software employs several distinct grids. Some examples are: an observation grid- an unstructured grid of points at which observed or measured physical quantities from instruments or satellites are associated- a highly-structured latitude-longitude grid of points spanning the earth at given latitude-longitude coordinates at which prognostic quantities are determined, and a computational lat-lon grid in which the pole has been moved to a different location to avoid computational instabilities. Each of these grids has a different structure and number of constituent points. In spite of that, there are numerous interactions between the grids, e.g., values on one grid must be interpolated to another, or, in other cases, grids need to be redistributed on the underlying parallel platform. The DAO has designed a parallel integrated library for grid manipulations (PILGRIM) to support the needed grid interactions with maximum efficiency. It offers a flexible interface to generate new grids, define transformations between grids and apply them. Basic communication is currently MPI, however the interfaces defined here could conceivably be implemented with other message-passing libraries, e.g., Cray SHMEM, or with shared-memory constructs. The library is written in Fortran 90. First performance results indicate that even difficult problems, such as above-mentioned pole rotation- a

  16. Manipulating magnetic anisotropy and ultrafast spin dynamics of magnetic nanostructures

    NASA Astrophysics Data System (ADS)

    Cheng, Zhao-Hua; He, Wei; Zhang, Xiang-Qun; Sun, Da-Li; Du, Hai-Feng; Wu, Qiong; Ye, Jun; Fang, Ya-Peng; Liu, Hao-Liang

    2015-07-01

    We present our extensive research into magnetic anisotropy. We tuned the terrace width of Si(111) substrate by a novel method: varying the direction of heating current and consequently manipulating the magnetic anisotropy of magnetic structures on the stepped substrate by decorating its atomic steps. Laser-induced ultrafast demagnetization of a CoFeB/MgO/CoFeB magnetic tunneling junction was explored by the time-resolved magneto-optical Kerr effect (TR-MOKE) for both the parallel state (P state) and the antiparallel state (AP state) of the magnetizations between two magnetic layers. It was observed that the demagnetization time is shorter and the magnitude of demagnetization is larger in the AP state than those in the P state. These behaviors are attributed to the ultrafast spin transfer between two CoFeB layers via the tunneling of hot electrons through the MgO barrier. Our observation indicates that ultrafast demagnetization can be engineered by the hot electron tunneling current. This opens the door to manipulate the ultrafast spin current in magnetic tunneling junctions. Furthermore, an all-optical TR-MOKE technique provides the flexibility for exploring the nonlinear magnetization dynamics in ferromagnetic materials, especially with metallic materials. Project supported by the National Basic Research Program of China (Grant Nos. 2015CB921403, 2011CB921801, and 2012CB933101) and the National Natural Science Foundation of China (Grant Nos. 51427801, 11374350, 51201179, and 11274361).

  17. Experimental object-level strategic control with cooperating manipulators

    NASA Technical Reports Server (NTRS)

    Schneider, Stanley A.; Cannon, Robert H., Jr.

    1993-01-01

    This article presents the high-level control module and user interface of the Dynamic and Strategic Control of Cooperating Manipulators (DASCCOM) project at Stanford University's Aerospace Robotics Laboratory. In addition to cooperative dynamic control, DASCCOM incorporates real-time vision-ased feedback, a novel strategic programming technique, and an iconic 'object-only' graphical user interface. By focusing on the vertical integration problem, we are examining not only these subsystems, but also their interfaces and interactions. The control system implements a multilevel hierarchical structure interconnected via a real-time network. At the highest level, a mouse-driven graphical user interface allows an operator to direct the activities of the system conceptually. Strategic command is provided by an event-driven finite state machine. This methodology provides a powerful yet flexible technique for managing concurrent system interactions. The dynamic controller implements object impedance control - an extension of Neville Hogan's impedance control concept to cooperative multiple-arm manipulation of a single object. This article concentrates on user interfacing techniques and strategic programming capabilities. These modules allow the user to directly specify conceptual object relationships. Experimental results are presented, showing the system locating and identifying a moving object, 'catching' it, and performing a simple cooperative assembly. Each of these operations is executed autonomously, with only object-level task-specification direction from a remote operator.

  18. H infinity controller design to a rigid-flexible satellite with two vibration modes

    NASA Astrophysics Data System (ADS)

    de Souza, A. G.; de Souza, L. C. G.

    2015-10-01

    The satellite attitude control system (ACS) design becomes more complex when the satellite structure has components like, flexible solar panels, antennas and mechanical manipulators. These flexible structures can interact with the satellite rigid parts during translational and/or rotational manoeuvre damaging the ACS pointing accuracy. Although, a well-designed controller can suppress such disturbances quickly, the controller error pointing may be limited by the minimum time necessary to suppress such disturbances thus affecting the satellite attitude acquisition. This paper deals with the rigid-flexible satellite ACS design using the H infinity method. The rigid-flexible satellite is represented by a beam connected to a central rigid hub at one end and free at the other one. The equations of motions are obtained considering small flexible deformations and the Euler-Bernoulli hypothesis. The results of the simulations have shown that the H-infinity controller was able to control the rigid motion and suppress the vibrations.

  19. Generalized flexibility-rigidity index

    NASA Astrophysics Data System (ADS)

    Nguyen, Duc Duy; Xia, Kelin; Wei, Guo-Wei

    2016-06-01

    Flexibility-rigidity index (FRI) has been developed as a robust, accurate, and efficient method for macromolecular thermal fluctuation analysis and B-factor prediction. The performance of FRI depends on its formulations of rigidity index and flexibility index. In this work, we introduce alternative rigidity and flexibility formulations. The structure of the classic Gaussian surface is utilized to construct a new type of rigidity index, which leads to a new class of rigidity densities with the classic Gaussian surface as a special case. Additionally, we introduce a new type of flexibility index based on the domain indicator property of normalized rigidity density. These generalized FRI (gFRI) methods have been extensively validated by the B-factor predictions of 364 proteins. Significantly outperforming the classic Gaussian network model, gFRI is a new generation of methodologies for accurate, robust, and efficient analysis of protein flexibility and fluctuation. Finally, gFRI based molecular surface generation and flexibility visualization are demonstrated.

  20. Microparticle manipulation in optical lattices

    NASA Astrophysics Data System (ADS)

    Mu, Weiqiang

    With the interference of several coherent beams, a periodical potential is produced for the particles trapped inside. The theoretical calculations show that the optical force applied on the particle in such optical lattice is in sinusoidal form. The force amplitudes vary greatly depending on the ratio of the particle size to the spacing of the optical lattice. A setup is constructed to demonstrate this dependence with two different methods: equipartition theorem and hydrodynamic-drag method. Based on this size dependence we develop an approach that allows tunable, size-dependent force selection of a subset of particles from an ensemble containing mixed particles. Combining a universal constant force with the sinusoidal optical force, a tilted washboard potential can be formed for the trapped particle. The diffusion of a particle over the barrier in this tilted washboard potential is briefly discussed. When the washboard potential oscillates, some interesting phenomena will happen: at high oscillation frequency, the particle's movement depends only on the oscillating amplitude; at low frequency, there are some combinations of the oscillation frequency and amplitude that induce the enhanced movement of the particle. This enhancement is first experimentally demonstrated with our setup. By implanting a single laser tweezers into the interferometric optical tweezers, we succeed in dynamically assembling designer colloidal lattices on the background of the interferometric optical tweezers. This new technique provides a flexible tool to design 2-d colloidal lattices.

  1. Flexible retinal electrode array

    DOEpatents

    Okandan, Murat; Wessendorf, Kurt O.; Christenson, Todd R.

    2006-10-24

    An electrode array which has applications for neural stimulation and sensing. The electrode array can include a large number of electrodes each of which is flexibly attached to a common substrate using a plurality of springs to allow the electrodes to move independently. The electrode array can be formed from a combination of bulk and surface micromachining, with electrode tips that can include an electroplated metal (e.g. platinum, iridium, gold or titanium) or a metal oxide (e.g. iridium oxide) for biocompatibility. The electrode array can be used to form a part of a neural prosthesis, and is particularly well adapted for use in an implantable retinal prosthesis where the electrodes can be tailored to provide a uniform gentle contact pressure with optional sensing of this contact pressure at one or more of the electrodes.

  2. Flexible weapons architecture design

    NASA Astrophysics Data System (ADS)

    Pyant, William C., III

    Present day air-delivered weapons are of a closed architecture, with little to no ability to tailor the weapon for the individual engagement. The closed architectures require weaponeers to make the target fit the weapon instead of fitting the individual weapons to a target. The concept of a flexible weapons aims to modularize weapons design using an open architecture shell into which different modules are inserted to achieve the desired target fractional damage while reducing cost and civilian casualties. This thesis shows that the architecture design factors of damage mechanism, fusing, weapons weight, guidance, and propulsion are significant in enhancing weapon performance objectives, and would benefit from modularization. Additionally, this thesis constructs an algorithm that can be used to design a weapon set for a particular target class based on these modular components.

  3. Flexible cloth seal assembly

    DOEpatents

    Bagepalli, Bharat Sampathkumar; Taura, Joseph Charles; Aksit, Mahmut Faruk; Demiroglu, Mehmet; Predmore, Daniel Ross

    1999-01-01

    A seal assembly having a flexible cloth seal which includes a shim assemblage surrounded by a cloth assemblage. A first tubular end portion, such as a gas turbine combustor, includes a longitudinal axis and has smooth and spaced-apart first and second surface portions defining a notch therebetween which is wider at its top than at its bottom and which extends outward from the axis. The second surface portion is outside curved, and a first edge of the cloth seal is positioned in the bottom of the notch. A second tubular end portion, such as a first stage nozzle, is located near, spaced apart from, and coaxially aligned with, the first tubular end portion. The second tubular end portion has a smooth third surface portion which surrounds at least a portion of the first tubular end portion and which is contacted by the cloth seal.

  4. Damped flexible seal

    DOEpatents

    DuBois, Neil J.; Amaral, Antonio M.

    1992-10-27

    A damped flexible seal assembly for a torpedo isolates the tailcone thereof rom vibrational energy present in the drive shaft assembly. A pair of outside flanges, each of which include an inwardly facing groove and an O-ring constrained therein, provide a watertight seal against the outer non-rotating surface of the drive shaft assembly. An inside flange includes an outwardly-facing groove and an O-ring constrained therein, and provides a watertight seal against the inner surface of the tail cone. Two cast-in-place elastomeric seals provide a watertight seal between the flanges and further provide a damping barrier between the outside flanges and the inside flanges for damping vibrational energy present in the drive shaft assembly before the energy can reach the tailcone through the seal assembly.

  5. Flexible cloth seal assembly

    DOEpatents

    Bagepalli, B.S.; Taura, J.C.; Aksit, M.F.; Demiroglu, M.; Predmore, D.R.

    1999-06-29

    A seal assembly is described having a flexible cloth seal which includes a shim assemblage surrounded by a cloth assemblage. A first tubular end portion, such as a gas turbine combustor, includes a longitudinal axis and has smooth and spaced-apart first and second surface portions defining a notch there between which is wider at its top than at its bottom and which extends outward from the axis. The second surface portion is outside curved, and a first edge of the cloth seal is positioned in the bottom of the notch. A second tubular end portion, such as a first stage nozzle, is located near, spaced apart from, and coaxially aligned with, the first tubular end portion. The second tubular end portion has a smooth third surface portion which surrounds at least a portion of the first tubular end portion and which is contacted by the cloth seal. 7 figs.

  6. Flexible swivel connection

    DOEpatents

    Hoh, J.C.

    1985-02-19

    A flexible swivel boot connector for connecting a first boot shield section to a second boot shield section, both first and second boot sections having openings therethrough, the second boot section having at least two adjacent accordian folds at the end having the opening, the second boot section being positioned through the opening of the first boot section such that a first of the accordian folds is within the first boot section and a second of the accordian folds is outside of the first boot, includes first and second annular discs, the first disc being positioned within and across the first accordian fold, the second disc being positioned within and across the second accordian fold, such that the first boot section is moveably and rigidly connected between the first and second accordian folds of the second boot section.

  7. Conformational flexibility of aspartame.

    PubMed

    Toniolo, Claudio; Temussi, Pierandrea

    2016-05-01

    L-Aspartyl-L-phenylalanine methyl ester, better known as aspartame, is not only one of the most used artificial sweeteners, but also a very interesting molecule with respect to the correlation between molecular structure and taste. The extreme conformational flexibility of this dipeptide posed a huge difficulty when researchers tried to use it as a lead compound to design new sweeteners. In particular, it was difficult to take advantage of its molecular model as a mold to infer the shape of the, then unknown, active site of the sweet taste receptor. Here, we follow the story of the 3D structural aspects of aspartame from early conformational studies to recent docking into homology models of the receptor. © 2016 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 376-384, 2016. PMID:27038223

  8. Control System Design Implementation and Preliminary Demonstration for a Tendon-Actuated Lightweight In-Space MANipulator (TALISMAN)

    NASA Technical Reports Server (NTRS)

    Komendera, Erik E.; Doggett, William R.; Dorsey, John T.; Debus, Thomas J.; Holub, Kris; Dougherty, Sean P.

    2015-01-01

    Satellite servicing is a high priority task for NASA and the space industry, addressing the needs of a variety of missions, and potentially lowering the overall cost of missions through refurbishment and reuse. However, the ability to service satellites is severely limited by the lack of long reach manipulation capability and inability to launch new devices due the end of the Space Transport System, or Space Shuttle Program. This paper describes the design and implementation of a control system for a Tendon-Actuated Lightweight In-Space MANipulator (TALISMAN), including; defining the forward and inverse kinematics, endpoint velocity to motor velocity, required cable tensions, and a proportional-integral-derivative (PID) controller. The tensions and velocities necessary to maneuver and capture small and large payloads are also discussed. To demonstrate the utility of the TALISMAN for satellite servicing, this paper also describes a satellite servicing demonstration using two TALISMAN prototypes to grasp and inspect a satellite mockup. Potential avenues for improving the control system are discussed.

  9. Kinematic analysis of a flexible six-DOF parallel mechanism.

    PubMed

    Jing, Feng-Shui; Tan, Min; Hou, Zeng-Guang; Liang, Zi-Ze; Wang, Yun-Kuan; Gupta, Madan M; Nikiforuk, Peter N

    2006-04-01

    In this paper, a new type of six-degrees of freedom (DOF) flexible parallel mechanism (FPM) is presented. This type of parallel mechanism possesses several favorable properties: (1) its number of DOFs is independent of the number of serial chains which make up the mechanism; (2) it has no kinematical singularities; (3) it is designed to move on rails, and therefore its workspace is much larger than that of a conventional parallel manipulator; and (4) without changing the number of DOFs and the kinematics of the mechanisms, the number of the serial chains can be reconfigured according to the needs of the tasks. These properties make the mechanism very preferable in practice, especially for such tasks as joining huge ship blocks, in which the manipulated objects vary dramatically both in weights and dimensions. Furthermore, the mechanism can be used as either a fully actuated system or an underactuated system. In the fully actuated case, the mechanism has six DOF motion capabilities and manipulation capabilities. However, in the underactuated case, the mechanism still has six DOF motion capabilities, but it has only five DOF manipulation capabilities. In this paper, both the inverse and forward kinematics are studied and expressed in a closed form. The workspace and singularity analysis of the mechanism are also presented. An example is presented to illustrate how to calculate the kinematics of the mechanism in both fully-actuated and underactuated cases. Finally, an application of such a mechanism to manufacturing industry is introduced. PMID:16602597

  10. Fuzzy logic control of telerobot manipulators

    NASA Technical Reports Server (NTRS)

    Franke, Ernest A.; Nedungadi, Ashok

    1992-01-01

    Telerobot systems for advanced applications will require manipulators with redundant 'degrees of freedom' (DOF) that are capable of adapting manipulator configurations to avoid obstacles while achieving the user specified goal. Conventional methods for control of manipulators (based on solution of the inverse kinematics) cannot be easily extended to these situations. Fuzzy logic control offers a possible solution to these needs. A current research program at SRI developed a fuzzy logic controller for a redundant, 4 DOF, planar manipulator. The manipulator end point trajectory can be specified by either a computer program (robot mode) or by manual input (teleoperator). The approach used expresses end-point error and the location of manipulator joints as fuzzy variables. Joint motions are determined by a fuzzy rule set without requiring solution of the inverse kinematics. Additional rules for sensor data, obstacle avoidance and preferred manipulator configuration, e.g., 'righty' or 'lefty', are easily accommodated. The procedure used to generate the fuzzy rules can be extended to higher DOF systems.

  11. Task based synthesis of serial manipulators

    PubMed Central

    Patel, Sarosh; Sobh, Tarek

    2015-01-01

    Computing the optimal geometric structure of manipulators is one of the most intricate problems in contemporary robot kinematics. Robotic manipulators are designed and built to perform certain predetermined tasks. There is a very close relationship between the structure of the manipulator and its kinematic performance. It is therefore important to incorporate such task requirements during the design and synthesis of the robotic manipulators. Such task requirements and performance constraints can be specified in terms of the required end-effector positions, orientations and velocities along the task trajectory. In this work, we present a comprehensive method to develop the optimal geometric structure (DH parameters) of a non-redundant six degree of freedom serial manipulator from task descriptions. In this work we define, develop and test a methodology to design optimal manipulator configurations based on task descriptions. This methodology is devised to investigate all possible manipulator configurations that can satisfy the task performance requirements under imposed joint constraints. Out of all the possible structures, the structures that can reach all the task points with the required orientations are selected. Next, these candidate structures are tested to see whether they can attain end-effector velocities in arbitrary directions within the user defined joint constraints, so that they can deliver the best kinematic performance. Additionally least power consuming configurations are also identified. PMID:26257946

  12. Development of a ten inch manipulators-based, flexible, broadband two-crystal spectrometer

    SciTech Connect

    Steel, A. B. Dunn, J.; Emig, J.; Beiersdorfer, P.; Brown, G. V.; Shepherd, R.; Marley, E. V.; Hoarty, D. J.

    2014-11-15

    We have developed and implemented a broadband X-ray spectrometer with a variable energy range for use at the Atomic Weapons Establishment's Orion Laser. The spectrometer covers an energy bandwidth of ∼1–2 keV using two independently mounted, movable Bragg diffraction crystals. Using combinations of cesium hydrogen pthlate, ammonium dihydrogen phosphate, and pentaerythritol crystals, spectra covering the 1.4–2.5, 1.85–3.15, or 3.55–5.1 keV energy bands have been measured. Image plate is used for detection owing to its high dynamic range. Background signals caused by high energy X-rays and particles commonly produced in high energy laser experiments are reduced by a series of tantalum baffles and filters installed between the source and crystal and also between the crystals and detector.

  13. Development of a ten inch manipulators-based, flexible, broadband two-crystal spectrometer

    NASA Astrophysics Data System (ADS)

    Steel, A. B.; Dunn, J.; Emig, J.; Beiersdorfer, P.; Brown, G. V.; Shepherd, R.; Marley, E. V.; Hoarty, D. J.

    2014-11-01

    We have developed and implemented a broadband X-ray spectrometer with a variable energy range for use at the Atomic Weapons Establishment's Orion Laser. The spectrometer covers an energy bandwidth of ˜1-2 keV using two independently mounted, movable Bragg diffraction crystals. Using combinations of cesium hydrogen pthlate, ammonium dihydrogen phosphate, and pentaerythritol crystals, spectra covering the 1.4-2.5, 1.85-3.15, or 3.55-5.1 keV energy bands have been measured. Image plate is used for detection owing to its high dynamic range. Background signals caused by high energy X-rays and particles commonly produced in high energy laser experiments are reduced by a series of tantalum baffles and filters installed between the source and crystal and also between the crystals and detector.

  14. Development of a ten inch manipulators-based, flexible, broadband two-crystal spectrometer.

    PubMed

    Steel, A B; Dunn, J; Emig, J; Beiersdorfer, P; Brown, G V; Shepherd, R; Marley, E V; Hoarty, D J

    2014-11-01

    We have developed and implemented a broadband X-ray spectrometer with a variable energy range for use at the Atomic Weapons Establishment's Orion Laser. The spectrometer covers an energy bandwidth of ∼1-2 keV using two independently mounted, movable Bragg diffraction crystals. Using combinations of cesium hydrogen pthlate, ammonium dihydrogen phosphate, and pentaerythritol crystals, spectra covering the 1.4-2.5, 1.85-3.15, or 3.55-5.1 keV energy bands have been measured. Image plate is used for detection owing to its high dynamic range. Background signals caused by high energy X-rays and particles commonly produced in high energy laser experiments are reduced by a series of tantalum baffles and filters installed between the source and crystal and also between the crystals and detector. PMID:25430186

  15. W-026, acceptance test report manipulator system

    SciTech Connect

    Watson, T.L.

    1997-04-15

    The purpose of the WRAP Manipulator System Acceptance Test Plan (ATP) is to verify that the 4 glovebox sets of WRAP manipulator components, including rail/carriage, slave arm, master controller and auxiliary equipment, meets the requirements of the functional segments of 14590 specification. The demonstration of performance elements of the ATP are performed as a part of the Assembly specifications. Manipulator integration is integrated in the performance testing of the gloveboxes. Each requirement of the Assembly specification will be carried out in conjunction with glovebox performance tests.

  16. Dynamically consistent Jacobian inverse for mobile manipulators

    NASA Astrophysics Data System (ADS)

    Ratajczak, Joanna; Tchoń, Krzysztof

    2016-06-01

    By analogy to the definition of the dynamically consistent Jacobian inverse for robotic manipulators, we have designed a dynamically consistent Jacobian inverse for mobile manipulators built of a non-holonomic mobile platform and a holonomic on-board manipulator. The endogenous configuration space approach has been exploited as a source of conceptual guidelines. The new inverse guarantees a decoupling of the motion in the operational space from the forces exerted in the endogenous configuration space and annihilated by the dual Jacobian inverse. A performance study of the new Jacobian inverse as a tool for motion planning is presented.

  17. Issues in advanced automation for manipulator control

    NASA Technical Reports Server (NTRS)

    Bejczy, A. K.

    1976-01-01

    This paper provides a brief description and analysis of the main issues in advanced autonomous control of manipulators as seen from a system point of view. The nature of manipulation is analyzed at some depth. A general multilevel structure is outlined for manipulator control organization which includes the human operator at the top level of the control structure. Different approaches to the development of advanced automation of mechanical arms are summarized. Recent work in the JPL teleoperator project is described, including control system, force/torque sensor, and control software development. Some results from control experiments are summarized.

  18. Single-sided continuous optoelectrowetting (SCOEW) for droplet manipulation with light patterns.

    PubMed

    Park, Sung-Yong; Teitell, Michael A; Chiou, Eric P Y

    2010-07-01

    Electrowetting-on-dielectric (EWOD) promises to be an important lab-on-a-chip approach for effectively manipulating droplets with electric field-controlled surface tension. Droplets manipulated in electrowetting-based devices are typically sandwiched between two parallel plates and actuated by digital electrodes. The size of pixilated electrodes limits the minimum droplet size that can be manipulated. Here, we report on a single-sided continuous optoelectrowetting (SCOEW) mechanism that enables light-patterned electrowetting modulation for continuous droplet manipulation on an open, featureless, and photoconductive surface. SCOEW overcomes the size limitation of physical pixilated electrodes by utilizing dynamic and reconfigurable optical patterns and enables the continuous transport, splitting, merging, and mixing of droplets with volumes ranging from 50 microL to 250 pL, over 5-orders of magnitude. This single-sided open configuration provides a flexible interface for integration with other microfluidic components, such as sample reservoirs through simple tubing. Light-triggered, parallel, and volume-tunable droplet injection with volume variation less than 1% has been demonstrated with SCOEW. The unique lateral field-driven optoelectrowetting mechanism also enables extremely low light intensity actuation, and droplet manipulation can be achieved by directly positioning the SCOEW chip on a LCD screen used in a laptop or portable cellular phone. PMID:20448870

  19. Teacher Flexibility in Mathematical Discussion

    ERIC Educational Resources Information Center

    Leikin, Roza; Dinur, Sariga

    2007-01-01

    The significance of discussion in mathematics classes has been prominently debated in the research literature. Different studies have stressed the importance of teacher flexibility in orchestrating the discussion. We introduce an operational definition of teacher flexibility. In a case study with one secondary-school mathematics teacher, we…

  20. Reconfigurable mobile manipulation for accident response

    SciTech Connect

    ANDERSON,ROBERT J.; MORSE,WILLIAM D.; SHIREY,DAVID L.; CDEBACA,DANIEL M.; HOFFMAN JR.,JOHN P.; LUCY,WILLIAM E.

    2000-06-06

    The need for a telerobotic vehicle with hazard sensing and integral manipulation capabilities has been identified for use in transportation accidents where nuclear weapons are involved. The Accident Response Mobile Manipulation System (ARMMS) platform has been developed to provide remote dexterous manipulation and hazard sensing for the Accident Response Group (ARG) at Sandia National Laboratories. The ARMMS' mobility platform is a military HMMWV [High Mobility Multipurpose Wheeled Vehicle] that is teleoperated over RF or Fiber Optic communication channels. ARMMS is equipped with two high strength Schilling Titan II manipulators and a suite of hazardous gas and radiation sensors. Recently, a modular telerobotic control architecture call SMART (Sandia Modular Architecture for Robotic and Teleoperation) has been applied to ARMMS. SMART enables input devices and many system behaviors to be rapidly configured in the field for specific mission needs. This paper summarizes current SMART developments applied to ARMMS.

  1. 75 FR 67657 - Prohibition of Market Manipulation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-03

    ... Manipulation, 71 FR 4244, 4253 (Jan. 26, 2006) (`` inal rule prohibits the use or employment of any device... indeed is easier to follow than a standard that requires the exercise of judgment in the light of all...

  2. Optoelectronic Tweezers for Microparticle and Cell Manipulation

    NASA Technical Reports Server (NTRS)

    Wu, Ming Chiang (Inventor); Chiou, Pei-Yu (Inventor); Ohta, Aaron T. (Inventor)

    2014-01-01

    An optical image-driven light induced dielectrophoresis (DEP) apparatus and method are described which provide for the manipulation of particles or cells with a diameter on the order of 100 micromillimeters or less. The apparatus is referred to as optoelectric tweezers (OET) and provides a number of advantages over conventional optical tweezers, in particular the ability to perform operations in parallel and over a large area without damage to living cells. The OET device generally comprises a planar liquid-filled structure having one or more portions which are photoconductive to convert incoming light to a change in the electric field pattern. The light patterns are dynamically generated to provide a number of manipulation structures that can manipulate single particles and cells or group of particles/cells. The OET preferably includes a microscopic imaging means to provide feedback for the optical manipulation, such as detecting position and characteristics wherein the light patterns are modulated accordingly.

  3. Optoelectronic tweezers for microparticle and cell manipulation

    NASA Technical Reports Server (NTRS)

    Wu, Ming Chiang (Inventor); Chiou, Pei Yu (Inventor); Ohta, Aaron T. (Inventor)

    2009-01-01

    An optical image-driven light induced dielectrophoresis (DEP) apparatus and method are described which provide for the manipulation of particles or cells with a diameter on the order of 100 .mu.m or less. The apparatus is referred to as optoelectric tweezers (OET) and provides a number of advantages over conventional optical tweezers, in particular the ability to perform operations in parallel and over a large area without damage to living cells. The OET device generally comprises a planar liquid-filled structure having one or more portions which are photoconductive to convert incoming light to a change in the electric field pattern. The light patterns are dynamically generated to provide a number of manipulation structures that can manipulate single particles and cells or groups of particles/cells. The OET preferably includes a microscopic imaging means to provide feedback for the optical manipulation, such as detecting position and characteristics wherein the light patterns are modulated accordingly.

  4. Tension Stiffened and Tendon Actuated Manipulator

    NASA Technical Reports Server (NTRS)

    Doggett, William R. (Inventor); Dorsey, John T. (Inventor); Ganoe, George G. (Inventor); King, Bruce D. (Inventor); Jones, Thomas C. (Inventor); Mercer, Charles D. (Inventor); Corbin, Cole K. (Inventor)

    2015-01-01

    A tension stiffened and tendon actuated manipulator is provided performing robotic-like movements when acquiring a payload. The manipulator design can be adapted for use in-space, lunar or other planetary installations as it is readily configurable for acquiring and precisely manipulating a payload in both a zero-g environment and in an environment with a gravity field. The manipulator includes a plurality of link arms, a hinge connecting adjacent link arms together to allow the adjacent link arms to rotate relative to each other and a cable actuation and tensioning system provided between adjacent link arms. The cable actuation and tensioning system includes a spreader arm and a plurality of driven and non-driven elements attached to the link arms and the spreader arm. At least one cable is routed around the driven and non-driven elements for actuating the hinge.

  5. Simulator for training remote-manipulator operators

    NASA Technical Reports Server (NTRS)

    Orr, D. H.; Ward, L. C.

    1979-01-01

    Six-degree-of-freedom simulator uses economical components. Reduction in complexity makes this or similar system cost-effective for training manipulator operators, such as those in industries handling nuclear wastes and hazardous chemicals.

  6. The Frankfurt School's Theory of Manipulation

    ERIC Educational Resources Information Center

    Petryszak, Nicholas

    1977-01-01

    Discusses the critical sociology of communication of the Frankfurt School suggesting that theorists such as Lowenthal, Adorno, and Habermas have outlined both the political economics of manipulation and the social psychological interaction between the audience and the media. (MH)

  7. Manipulator path planning in 3-dimensional space

    NASA Astrophysics Data System (ADS)

    Pavlov, Dmitry A.

    2006-04-01

    Present paper is aimed to work out efficient algorithm of multi-chain manipulator path planning in 3D space with static polygonal obstacles. The resulting solution is based on navigational maps approach. Using this approach, manipulator features are considered as intellectual agent, and reachability information is stored in compact form. This enables fast adaptation to arbitrary parameters of manipulator and workspace. The paper describes two algorithms: (i) a local walkthrough with obstacle avoidance, and (ii) incremental navigational map building, performed at running stage. Both algorithms take an extensive use of the specific features of the task. Working simultaneously, they allow real-time manipulator path planning, as well as self-learning in idle mode. Algorithms are implemented as a demonstration program.

  8. Hybrid Image-Plane/Stereo Manipulation

    NASA Technical Reports Server (NTRS)

    Baumgartner, Eric; Robinson, Matthew

    2004-01-01

    Hybrid Image-Plane/Stereo (HIPS) manipulation is a method of processing image data, and of controlling a robotic manipulator arm in response to the data, that enables the manipulator arm to place an end-effector (an instrument or tool) precisely with respect to a target (see figure). Unlike other stereoscopic machine-vision-based methods of controlling robots, this method is robust in the face of calibration errors and changes in calibration during operation. In this method, a stereoscopic pair of cameras on the robot first acquires images of the manipulator at a set of predefined poses. The image data are processed to obtain image-plane coordinates of known visible features of the end-effector. Next, there is computed an initial calibration in the form of a mapping between (1) the image-plane coordinates and (2) the nominal three-dimensional coordinates of the noted end-effector features in a reference frame fixed to the main robot body at the base of the manipulator. The nominal three-dimensional coordinates are obtained by use of the nominal forward kinematics of the manipulator arm that is, calculated by use of the currently measured manipulator joint angles and previously measured lengths of manipulator arm segments under the assumption that the arm segments are rigid, that the arm lengths are constant, and that there is no backlash. It is understood from the outset that these nominal three-dimensional coordinates are likely to contain possibly significant calibration errors, but the effects of the errors are progressively reduced, as described next. As the end-effector is moved toward the target, the calibration is updated repeatedly by use of data from newly acquired images of the end-effector and of the corresponding nominal coordinates in the manipulator reference frame. By use of the updated calibration, the coordinates of the target are computed in manipulator-reference-frame coordinates and then used to the necessary manipulator joint angles to position

  9. Manipulating Quantum Pathways on the Fly

    NASA Astrophysics Data System (ADS)

    Rey-de-Castro, Roberto; Leghtas, Zaki; Rabitz, Herschel

    2013-05-01

    The expectation value of a quantum system observable can be written as a sum over interfering pathway amplitudes. In this Letter, we demonstrate for the fist time adaptive manipulation of quantum pathways using the Hamiltonian encoding-observable decoding (HE-OD) technique. The principles of HE-OD are illustrated for population transfer in atomic rubidium using shaped femtosecond laser pulses. The ability to manipulate multiple pathway amplitudes is of fundamental importance in all quantum control applications.

  10. Ecological consequences of manipulative parasites: chapter 9

    USGS Publications Warehouse

    Lafferty, Kevin D.; Kuris, A. M.

    2012-01-01

    Parasitic "puppet masters", with their twisted, self-serving life history strategies and impressive evolutionary takeovers of host minds, capture the imagination of listeners—even those that might not normally fi nd the topic of parasitism appealing (which includes most everyone). A favorite anecdote concerns the trematode Leucochloridium paradoxum migrating to the eyestalks of its intermediate host snail and pulsating its colored body, presumably to attract the predatory birds that are the final hosts for the worm. Identifying a parasite as “manipulative” infers that a change in host behavior or appearance is a direct consequence of the parasite’s adaptive actions that, on average, will increase the fi tness of the parasite. The list of parasites that manipulate their hosts is long and growing. Holmes and Bethel (1972) presented the earliest comprehensive review and brought the subject to mainstream ecologists. Over two decades ago, Andy Dobson (1988) listed seven cestodes, seven trematodes, ten acanthocephalans, and three nematodes that manipulated host behavior. Fifteen years later, Janice Moore (2002) filled a book with examples. The five infectious trophic strategies, typical parasites (macroparasites), pathogens, trophically transmitted parasites, parasitic castrators, and parasitoids (Kuris and Lafferty 2000; Lafferty and Kuris 2002, 2009) can modify host behavior, but the likelihood that a parasite manipulates behavior differs among strategies. The most studied infectious agents, non-trophically transmitted pathogens and macroparasites, have enormous public health, veterinary, and wildlife disease importance, yet few manipulate host behavior. The beststudied manipulative infectious agents are trophically transmitted parasites in their prey intermediate hosts. Parasitoids and parasitic castrators can also manipulate host behavior, but for different purposes and with different implications. Several studies of manipulative parasites conclude with

  11. Efficient Computation Of Manipulator Inertia Matrix

    NASA Technical Reports Server (NTRS)

    Fijany, Amir; Bejczy, Antal K.

    1991-01-01

    Improved method for computation of manipulator inertia matrix developed, based on concept of spatial inertia of composite rigid body. Required for implementation of advanced dynamic-control schemes as well as dynamic simulation of manipulator motion. Motivated by increasing demand for fast algorithms to provide real-time control and simulation capability and, particularly, need for faster-than-real-time simulation capability, required in many anticipated space teleoperation applications.

  12. On the manipulability of dual cooperative robots

    NASA Technical Reports Server (NTRS)

    Chiacchio, P.; Chiaverini, S.; Sciavicco, L.; Siciliano, B.

    1989-01-01

    The definition of manipulability ellipsoids for dual robot systems is given. A suitable kineto-static formulation for dual cooperative robots is adopted which allows for a global task space description of external and internal forces, and relative velocities. The well known concepts of force and velocity manipulability ellipsoids for a single robot are formally extended and the contributions of the two single robots to the cooperative system ellipsoids are illustrated. Duality properties are discussed. A practical case study is developed.

  13. Flexible phosphorene devices and circuits

    NASA Astrophysics Data System (ADS)

    Zhu, Weinan; Yogeesh, Maruthi N.; Akinwande, Deji

    2015-05-01

    Two-dimensional (2D) semiconductors with high carrier mobilities and sizeable bandgap are desirable for future high-speed and low power mechanically flexible nanoelectronics. In this work, we report encapsulated bottom-gated black phosphorus (BP) field-effect transistors (FETs) on flexible polyimide affording maximum carrier mobility of about 310cm2/V•s and current on/off ratio exceeding 103. Essential circuits of flexible electronic systems enabled by the device ambipolar functionality, high-mobility and current saturation are demonstrated in this work, including digital inverter, frequency doubler, and analog amplifiers featuring a voltage gain of ~8.7, which is the state-of-the-art value for flexible 2D semiconductor based amplifiers. In addition, we demonstrate the single FET based flexible BP amplitude-modulated (AM) demodulator, an active stage in radio receivers.

  14. [The flexibility of family medicine].

    PubMed

    Minguet, C; Aubrege, A; Aubart, M; Cornuz, J; di Patrizio, P; Du Boullay, D; Farghadani, H; Flammang, M; Haas, N; Kacenelenbogen, N; Kopp, M; Leners, J C; Levêque, M; Mbengue, M; Paur, H; Paur, I; Raphaël, F; Rausch, S; Shetgen, M; Stein R; Tabouring, P; Thomas, J M; Vignon, G

    2015-01-01

    We are a European academic group of family doctors and we propose a definition of flexibility in family medicine. A review of the literature shows that flexibility and complexity are emerging concepts in the field of family practice. The outcomes of a workshop at the WONCA-Europe congress in 2014 are discussed. The flexibility is a capability of the general practitioner to deal with complex clinical situations in a biomedical and societal changing world. Flexibility is framed by ethics. It could improve the quality of care, be useful against burnout and used in medical research. In conclusion, family medicine should adopt a specific definition of the flexibility describing its specificity, a useful and teachable capacity. PMID:26946851

  15. Conformational flexibility of mephenesin.

    PubMed

    Écija, Patricia; Evangelisti, Luca; Vallejo, Montserrat; Basterretxea, Francisco J; Lesarri, Alberto; Castaño, Fernando; Caminati, Walther; Cocinero, Emilio J

    2014-05-22

    The mephenesin molecule (3-(2-methylphenoxy)propane-1,2-diol) serves as a test bank to explore several structural and dynamical issues, such as conformational flexibility, the orientation of the carbon linear chain relative to the benzene plane, or the effect of substituent position on the rotational barrier of a methyl group. The molecule has been studied by rotational spectroscopy in the 4-18 GHz frequency range by Fourier-transform methods in a supersonic expansion. The experiment has been backed by a previous conformational search plus optimization of the lowest energy structures by ab initio and density functional quantum calculations. The three lowest-lying conformers that can interconvert to each other by simple bond rotations have been detected in the jet. Rotational parameters for all structures have been obtained, and methyl torsional barriers have been determined for the two lowest-lying rotamers. The lowest-lying structure of mephenesin is highly planar, with all carbon atoms lying nearly in the benzene ring plane, and is stabilized by the formation of cooperative intramolecular hydrogen bonding. An estimation of the relative abundance of the detected conformers indicates that the energetically most stable conformer will have an abundance near 80% at temperatures relevant for biological activity. PMID:24754523

  16. Direct manipulation of virtual objects

    NASA Astrophysics Data System (ADS)

    Nguyen, Long K.

    Interacting with a Virtual Environment (VE) generally requires the user to correctly perceive the relative position and orientation of virtual objects. For applications requiring interaction in personal space, the user may also need to accurately judge the position of the virtual object relative to that of a real object, for example, a virtual button and the user's real hand. This is difficult since VEs generally only provide a subset of the cues experienced in the real world. Complicating matters further, VEs presented by currently available visual displays may be inaccurate or distorted due to technological limitations. Fundamental physiological and psychological aspects of vision as they pertain to the task of object manipulation were thoroughly reviewed. Other sensory modalities -- proprioception, haptics, and audition -- and their cross-interactions with each other and with vision are briefly discussed. Visual display technologies, the primary component of any VE, were canvassed and compared. Current applications and research were gathered and categorized by different VE types and object interaction techniques. While object interaction research abounds in the literature, pockets of research gaps remain. Direct, dexterous, manual interaction with virtual objects in Mixed Reality (MR), where the real, seen hand accurately and effectively interacts with virtual objects, has not yet been fully quantified. An experimental test bed was designed to provide the highest accuracy attainable for salient visual cues in personal space. Optical alignment and user calibration were carefully performed. The test bed accommodated the full continuum of VE types and sensory modalities for comprehensive comparison studies. Experimental designs included two sets, each measuring depth perception and object interaction. The first set addressed the extreme end points of the Reality-Virtuality (R-V) continuum -- Immersive Virtual Environment (IVE) and Reality Environment (RE). This

  17. Control and dynamics of a flexible spacecraft during stationkeeping maneuvers

    NASA Technical Reports Server (NTRS)

    Liu, D.; Yocum, J.; Kang, D. S.

    1991-01-01

    A case study of a spacecraft having flexible solar arrays is presented. A stationkeeping attitude control mode using both earth and rate gyro reference signals and a flexible vehicle dynamics modeling and implementation is discussed. The control system is designed to achieve both pointing accuracy and structural mode stability during stationkeeping maneuvers. Reduction of structural mode interactions over the entire mode duration is presented. The control mode using a discrete time observer structure is described to show the convergence of the spacecraft attitude transients during Delta-V thrusting maneuvers without preloading thrusting bias to the onboard control processor. The simulation performance using the three axis, body stabilized nonlinear dynamics is provided. The details of a five body dynamics model are discussed. The spacecraft is modeled as a central rigid body having cantilevered flexible antennas, a pair of flexible articulated solar arrays, and to gimballed momentum wheels. The vehicle is free to undergo unrestricted rotations and translations relative to inertial space. A direct implementation of the equations of motion is compared to an indirect implementation that uses a symbolic manipulation software to generate rigid body equations.

  18. A class of stabilizing controllers for flexible multibody systems

    NASA Technical Reports Server (NTRS)

    Joshi, Suresh M.; Kelkar, Atul G.; Maghami, Peiman G.

    1995-01-01

    The problem of controlling a class of nonlinear multibody flexible space systems consisting of a flexible central body to which a number of articulated appendages are attached is considered. Collocated actuators and sensors are assumed, and global asymptotic stability of such systems is established under a nonlinear dissipative control law. The stability is shown to be robust to unmodeled dynamics and parametric uncertainties. For a special case in which the attitude motion of the central body is small, the system, although still nonlinear, is shown to be stabilized by linear dissipative control laws. Two types of linear controllers are considered: static dissipative (constant gain) and dynamic dissipative. The static dissipative control law is also shown to provide robust stability in the presence of certain classes of actuator and sensor nonlinearities and actuator dynamics. The results obtained for this special case can also be readily applied for controlling single-body linear flexible space structures. For this case, a synthesis technique for the design of a suboptimal dynamic dissipative controller is also presented. The results obtained in this paper are applicable to a broad class of multibody and single-body systems such as flexible multilink manipulators, multipayload space platforms, and space antennas. The stability proofs use the Lyapunov approach and exploit the inherent passivity of such systems.

  19. Swarming: flexible roaming plans.

    PubMed

    Partridge, Jonathan D; Harshey, Rasika M

    2013-03-01

    Movement over an agar surface via swarming motility is subject to formidable challenges not encountered during swimming. Bacteria display a great deal of flexibility in coping with these challenges, which include attracting water to the surface, overcoming frictional forces, and reducing surface tension. Bacteria that swarm on "hard" agar surfaces (robust swarmers) display a hyperflagellated and hyperelongated morphology. Bacteria requiring a "softer" agar surface (temperate swarmers) do not exhibit such a dramatic morphology. For polarly flagellated robust swarmers, there is good evidence that restriction of flagellar rotation somehow signals the induction of a large number of lateral flagella, but this scenario is apparently not relevant to temperate swarmers. Swarming bacteria can be further subdivided by their requirement for multiple stators (Mot proteins) or a stator-associated protein (FliL), secretion of essential polysaccharides, cell density-dependent gene regulation including surfactant synthesis, a functional chemotaxis signaling pathway, appropriate cyclic (c)-di-GMP levels, induction of virulence determinants, and various nutritional requirements such as iron limitation or nitrate availability. Swarming strategies are as diverse as the bacteria that utilize them. The strength of these numerous designs stems from the vantage point they offer for understanding mechanisms for effective colonization of surface niches, acquisition of pathogenic potential, and identification of environmental signals that regulate swarming. The signature swirling and streaming motion within a swarm is an interesting phenomenon in and of itself, an emergent behavior with properties similar to flocking behavior in diverse systems, including birds and fish, providing a convenient new avenue for modeling such behavior. PMID:23264580

  20. Swarming: Flexible Roaming Plans

    PubMed Central

    Partridge, Jonathan D.

    2013-01-01

    Movement over an agar surface via swarming motility is subject to formidable challenges not encountered during swimming. Bacteria display a great deal of flexibility in coping with these challenges, which include attracting water to the surface, overcoming frictional forces, and reducing surface tension. Bacteria that swarm on “hard” agar surfaces (robust swarmers) display a hyperflagellated and hyperelongated morphology. Bacteria requiring a “softer” agar surface (temperate swarmers) do not exhibit such a dramatic morphology. For polarly flagellated robust swarmers, there is good evidence that restriction of flagellar rotation somehow signals the induction of a large number of lateral flagella, but this scenario is apparently not relevant to temperate swarmers. Swarming bacteria can be further subdivided by their requirement for multiple stators (Mot proteins) or a stator-associated protein (FliL), secretion of essential polysaccharides, cell density-dependent gene regulation including surfactant synthesis, a functional chemotaxis signaling pathway, appropriate cyclic (c)-di-GMP levels, induction of virulence determinants, and various nutritional requirements such as iron limitation or nitrate availability. Swarming strategies are as diverse as the bacteria that utilize them. The strength of these numerous designs stems from the vantage point they offer for understanding mechanisms for effective colonization of surface niches, acquisition of pathogenic potential, and identification of environmental signals that regulate swarming. The signature swirling and streaming motion within a swarm is an interesting phenomenon in and of itself, an emergent behavior with properties similar to flocking behavior in diverse systems, including birds and fish, providing a convenient new avenue for modeling such behavior. PMID:23264580

  1. Recursive dynamics for flexible multibody systems using spatial operators

    NASA Technical Reports Server (NTRS)

    Jain, A.; Rodriguez, G.

    1990-01-01

    Due to their structural flexibility, spacecraft and space manipulators are multibody systems with complex dynamics and possess a large number of degrees of freedom. Here the spatial operator algebra methodology is used to develop a new dynamics formulation and spatially recursive algorithms for such flexible multibody systems. A key feature of the formulation is that the operator description of the flexible system dynamics is identical in form to the corresponding operator description of the dynamics of rigid multibody systems. A significant advantage of this unifying approach is that it allows ideas and techniques for rigid multibody systems to be easily applied to flexible multibody systems. The algorithms use standard finite-element and assumed modes models for the individual body deformation. A Newton-Euler Operator Factorization of the mass matrix of the multibody system is first developed. It forms the basis for recursive algorithms such as for the inverse dynamics, the computation of the mass matrix, and the composite body forward dynamics for the system. Subsequently, an alternative Innovations Operator Factorization of the mass matrix, each of whose factors is invertible, is developed. It leads to an operator expression for the inverse of the mass matrix, and forms the basis for the recursive articulated body forward dynamics algorithm for the flexible multibody system. For simplicity, most of the development here focuses on serial chain multibody systems. However, extensions of the algorithms to general topology flexible multibody systems are described. While the computational cost of the algorithms depends on factors such as the topology and the amount of flexibility in the multibody system, in general, it appears that in contrast to the rigid multibody case, the articulated body forward dynamics algorithm is the more efficient algorithm for flexible multibody systems containing even a small number of flexible bodies. The variety of algorithms described

  2. Electronic applications of flexible graphite

    NASA Astrophysics Data System (ADS)

    Luo, Xiangcheng; Chugh, Randy; Biller, Brian C.; Hoi, Yie Meng; Chung, D. D. L.

    2002-05-01

    Flexible graphite is effective for electronic applications, specifically electromagnetic interference (EMI) gasketing, resistive heating, thermoelectric-energy generation, and heat dissipation. It is comparable to or better than conductive-filled silicone materials for EMI gasketing. The shielding effectiveness reaches 125 dB. Flexible graphite as a heating element provides temperatures up to 980°C, response half-time down to 4 sec, and heat output at 60 sec up to 5600 J. The through-thickness, absolute thermoelectric power of flexible graphite is -2.6 µV/°C. Flexible graphite is effective as a thermal-interface material if the thickness is low (0.13 mm), the density is low (1.1 g/cm3), and the contact pressure is high (11.1 MPa). These applications make use of the flexibility and compliance of flexible graphite, in addition to its electronic and thermal behavior. Compliance is particularly important for the use of flexible graphite as interface materials, whether the interface is electrom agnetic, thermoelectric, or thermal.

  3. Embedded electro-conductive yarn for shape sensing of soft robotic manipulators.

    PubMed

    Wurdemann, Helge A; Sareh, Sina; Shafti, Ali; Noh, Yohan; Faragasso, Angela; Chathuranga, Damith S; Hongbin Liu; Hirai, Shinichi; Althoefer, Kaspar

    2015-08-01

    Flexible soft and stiffness-controllable surgical manipulators enhance the manoeuvrability of surgical tools during Minimally Invasive Surgery (MIS), as opposed to conventional rigid laparoscopic instruments. These flexible and soft robotic systems allow bending around organs, navigating through complex anatomical pathways inside the human body and interacting inherently safe with its soft environment. Shape sensing in such systems is a challenge and one essential requirement for precise position feedback control of soft robots. This paper builds on our previous work integrating multiple optical fibres into a soft manipulator to estimate the robot's pose using light intensity modulation. Here, we present an enhanced version of our embedded bending/shape sensor based on electro-conductive yarn. The new system is miniaturised and able to measure bending behaviour as well as elongation. The integrated yarn material is helically wrapped around an elastic strap and protected inside a 1.5mm outer-diameter stretchable pipe. Three of these resulting stretch sensors are integrated in the periphery of a pneumatically actuated soft manipulator for direct measurement of the actuation chamber lengths. The capability of the sensing system in measuring the bending curvature and elongation of the arm is evaluated. PMID:26738155

  4. Intelligent Hierarchical Modal Control of a Novel Manipulator with Slewing and Deployable Links

    NASA Astrophysics Data System (ADS)

    Modi, V. J.; Zhang, J.; de Silva, C. W.

    between the crisp controller, which regulates the servomotors at the bottom layer, and the knowledge-based controller at the top layer. The third uppermost layer of the control system has the knowledge-base and inference engine to make decisions, which achieve the overall control objective, particularly by improving the performance of low-level direct control. This layer can serve such functions as monitoring the performance of the overall system, assessment of the quality of operation, tuning of the low-level direct controller, and general supervisory control. In this layer, there is a high degree of information fuzziness and a relatively low control bandwidth. 3. Typical Simulation Results This hierarchical control system is used to suppress vibrations of the manipulator with flexible joint and links as well as supported by a flexible orbiting platform. The effectiveness of the control system is assessed through simulation studies by investigating how the vibrations caused by different initial disturbances are suppressed. The resutls showed that when regulated by the hieraicyical controller, the joint vibrations were eliminated much faster than that by the LQR. The hierauchical control system was found to reduce the amplitude of the vibraiton significantly in comparison with those by the LQR. [1]Nagata, T., Modi, V. J., and Matsuo, H., " An Approach to Dynamics and Control of Flexible Systems", Collection [2]Caron, M., " Planar Dynamics and Control of Space-Based Flexible Manipulators with Slewing and Deployable [3]Chu, M. S. T., " Design, Construction and Operation of a Variable Geometry Manipulator", M. A. Sc. Thesis, The

  5. Flexible sensors for biomedical technology.

    PubMed

    Vilela, Diana; Romeo, Agostino; Sánchez, Samuel

    2016-02-01

    Flexible sensing devices have gained a great deal of attention among the scientific community in recent years. The application of flexible sensors spans over several fields, including medicine, industrial automation, robotics, security, and human-machine interfacing. In particular, non-invasive health-monitoring devices are expected to play a key role in the improvement of patient life and in reducing costs associated with clinical and biomedical diagnostic procedures. Here, we focus on recent advances achieved in flexible devices applied on the human skin for biomedical and healthcare purposes. PMID:26675174

  6. Guideline Implementation: Processing Flexible Endoscopes.

    PubMed

    Bashaw, Marie A

    2016-09-01

    The updated AORN "Guideline for processing flexible endoscopes" provides guidance to perioperative, endoscopy, and sterile processing personnel for processing all types of reusable flexible endoscopes and accessories in all procedural settings. This article focuses on key points of the guideline to help perioperative personnel safely and effectively process flexible endoscopes to prevent infection transmission. The key points address verification of manual cleaning, mechanical cleaning and processing, storage in a drying cabinet, determination of maximum storage time before reprocessing is needed, and considerations for implementing a microbiologic surveillance program. Perioperative RNs should review the complete guideline for additional information and for guidance when writing and updating policies and procedures. PMID:27568535

  7. Rolling-cuff flexible bellows

    DOEpatents

    Lambert, D.R.

    1982-09-27

    A flexible connector apparatus used to join two stiff non-deformable members, such as piping, is described. The apparatus is provided with one or more flexible sections or assemblies each utilizing a bellows of a rolling cuff type connected between two ridge members, with the bellows being supported by a back-up ring, such that only the curved end sections of the bellows are unsupported. Thus, the bellows can be considered as being of a tube-shaped configuration and thus have high pressure resistance. The components of the flexible apparatus are sealed or welded one to another such that it is fluid tight.

  8. High performance flexible heat pipes

    NASA Technical Reports Server (NTRS)

    Shaubach, R. M.; Gernert, N. J.

    1985-01-01

    A Phase I SBIR NASA program for developing and demonstrating high-performance flexible heat pipes for use in the thermal management of spacecraft is examined. The program combines several technologies such as flexible screen arteries and high-performance circumferential distribution wicks within an envelope which is flexible in the adiabatic heat transport zone. The first six months of work during which the Phase I contract goal were met, are described. Consideration is given to the heat-pipe performance requirements. A preliminary evaluation shows that the power requirement for Phase II of the program is 30.5 kilowatt meters at an operating temperature from 0 to 100 C.

  9. Flexible Learning in a Digital World.

    ERIC Educational Resources Information Center

    Collis, Betty; Moonen, Jef

    2002-01-01

    Defines flexible learning and describes components of flexible learning in higher education, including technology, pedagogy or instructional approach, implementation strategies, and institutional framework. Considers factors constraining learning flexibility; changing student characteristics; and the need for lifelong learning, particularly in the…

  10. Precision manipulation with a dextrous robot hand

    NASA Astrophysics Data System (ADS)

    Michelman, Paul

    1994-01-01

    In this thesis, we discuss a framework for describing and synthesizing precision manipulation tasks with a robot hand. Precision manipulations are those in which the motions of grasped objects are caused by finger motions alone (as distinct from arm or wrist motion). Experiments demonstrating the capabilities of the Utah-MIT hand are presented. This work begins by examining current research on biological motor control to raise a number of questions. For example, is the control centralized and organized by a central processor? Or is the control distributed throughout the nervous system? Motor control research on manipulation has focused on developing classifications of hand motions, concentrating solely on finger motions, while neglecting grasp stability and interaction forces that occur in manipulation. In addition, these taxonomies have not been explicitly functional. This thesis defines and analyzes a basic set of manipulation strategies that includes both position and force trajectories. The fundamental purposes of the manipulations are: (1) rectilinear and rotational motion of grasped objects of different geometries; and (2) the application of forces and moments against the environment by the grasped objects. First, task partitioning is described to allocate the fingers their roles in the task. Second, for each strategy, the mechanics and workspace of the tasks are analyzed geometrically to determine the gross finger trajectories required to achieve the tasks. Techniques illustrating the combination of simple manipulations into complex, multiple degree-of-freedom tasks are presented. There is a discussion of several tasks that use multiple elementary strategies. The tasks described are removing the top of a childproof medicine bottle, putting the top back on, rotating and regrasping a block and a cylinder within the grasp. Finally, experimental results are presented. The experimental setup at Columbia University's Center for Research in Intelligent Systems and

  11. Better with Byzantine: Manipulation-Optimal Mechanisms

    NASA Astrophysics Data System (ADS)

    Othman, Abraham; Sandholm, Tuomas

    A mechanism is manipulable if it is in some agents’ best interest to misrepresent their private information. The revelation principle establishes that, roughly, anything that can be accomplished by a manipulable mechanism can also be accomplished with a truthful mechanism. Yet agents often fail to play their optimal manipulations due to computational limitations or various flavors of incompetence and cognitive biases. Thus, manipulable mechanisms in particular should anticipate byzantine play. We study manipulation-optimal mechanisms: mechanisms that are undominated by truthful mechanisms when agents act fully rationally, and do better than any truthful mechanism if any agent fails to act rationally in any way. This enables the mechanism designer to do better than the revelation principle would suggest, and obviates the need to predict byzantine agents’ irrational behavior. We prove a host of possibility and impossibility results for the concept which have the impression of broadly limiting possibility. These results are largely in line with the revelation principle, although the considerations are more subtle and the impossibility not universal.

  12. Distinguishing manipulated stocks via trading network analysis

    NASA Astrophysics Data System (ADS)

    Sun, Xiao-Qian; Cheng, Xue-Qi; Shen, Hua-Wei; Wang, Zhao-Yang

    2011-10-01

    Manipulation is an important issue for both developed and emerging stock markets. For the study of manipulation, it is critical to analyze investor behavior in the stock market. In this paper, an analysis of the full transaction records of over a hundred stocks in a one-year period is conducted. For each stock, a trading network is constructed to characterize the relations among its investors. In trading networks, nodes represent investors and a directed link connects a stock seller to a buyer with the total trade size as the weight of the link, and the node strength is the sum of all edge weights of a node. For all these trading networks, we find that the node degree and node strength both have tails following a power-law distribution. Compared with non-manipulated stocks, manipulated stocks have a high lower bound of the power-law tail, a high average degree of the trading network and a low correlation between the price return and the seller-buyer ratio. These findings may help us to detect manipulated stocks.

  13. Dynamic whole-body robotic manipulation

    NASA Astrophysics Data System (ADS)

    Abe, Yeuhi; Stephens, Benjamin; Murphy, Michael P.; Rizzi, Alfred A.

    2013-05-01

    The creation of dynamic manipulation behaviors for high degree of freedom, mobile robots will allow them to accomplish increasingly difficult tasks in the field. We are investigating how the coordinated use of the body, legs, and integrated manipulator, on a mobile robot, can improve the strength, velocity, and workspace when handling heavy objects. We envision that such a capability would aid in a search and rescue scenario when clearing obstacles from a path or searching a rubble pile quickly. Manipulating heavy objects is especially challenging because the dynamic forces are high and a legged system must coordinate all its degrees of freedom to accomplish tasks while maintaining balance. To accomplish these types of manipulation tasks, we use trajectory optimization techniques to generate feasible open-loop behaviors for our 28 dof quadruped robot (BigDog) by planning trajectories in a 13 dimensional space. We apply the Covariance Matrix Adaptation (CMA) algorithm to solve for trajectories that optimize task performance while also obeying important constraints such as torque and velocity limits, kinematic limits, and center of pressure location. These open-loop behaviors are then used to generate desired feed-forward body forces and foot step locations, which enable tracking on the robot. Some hardware results for cinderblock throwing are demonstrated on the BigDog quadruped platform augmented with a human-arm-like manipulator. The results are analogous to how a human athlete maximizes distance in the discus event by performing a precise sequence of choreographed steps.

  14. Control and applications of cooperating disparate robotic manipulators relevant to waste management

    SciTech Connect

    Lew, J.Y.; Book, W.J. )

    1990-01-01

    Remote handling in nuclear waste management requires a robotic system with precise motion as well as a large work space. The concept of a small arm mounted on the end of a large arm may satisfy such needs. The performance of such a serial configuration, however, lacks payload capacity, which is a crucial factor for handling a massive object. This configuration also induces more flexibility on the structure and requires a more complicated control scheme to eliminate its residual vibrations. To overcome these problems, bracing the tip of the small arm (not the large arm) on a stationary frame is considered. By forming a closed kinematic chain, bracing increases structural stiffness and payload capacity. This crane-human configuration may be analogous to the topology of bracing at the top of the small arm and having an end effector at the middle of the chain. Thus, the large arm does the precise positioning of a human. This topology gives motivation to develop a coordination strategy for disparate large and small robotic manipulators. In the Flexible Automation Laboratory at Georgia Institute of Technology, a large experimental arm, designated RALF (Robotic Arm, Large and Flexible), has been constructed and placed under computer control. Also, a small experimental arm, SAM (Small Articulated Manipulator), has been constructed and is being tested under single joint control. SAM will be mounted on the end of RALF. Experimental studies are scheduled to verify the feasibility of the proposed concepts.

  15. Real-Time Strategy Game Training: Emergence of a Cognitive Flexibility Trait

    PubMed Central

    Glass, Brian D.; Maddox, W. Todd; Love, Bradley C.

    2013-01-01

    Training in action video games can increase the speed of perceptual processing. However, it is unknown whether video-game training can lead to broad-based changes in higher-level competencies such as cognitive flexibility, a core and neurally distributed component of cognition. To determine whether video gaming can enhance cognitive flexibility and, if so, why these changes occur, the current study compares two versions of a real-time strategy (RTS) game. Using a meta-analytic Bayes factor approach, we found that the gaming condition that emphasized maintenance and rapid switching between multiple information and action sources led to a large increase in cognitive flexibility as measured by a wide array of non-video gaming tasks. Theoretically, the results suggest that the distributed brain networks supporting cognitive flexibility can be tuned by engrossing video game experience that stresses maintenance and rapid manipulation of multiple information sources. Practically, these results suggest avenues for increasing cognitive function. PMID:23950921

  16. Real-time strategy game training: emergence of a cognitive flexibility trait.

    PubMed

    Glass, Brian D; Maddox, W Todd; Love, Bradley C

    2013-01-01

    Training in action video games can increase the speed of perceptual processing. However, it is unknown whether video-game training can lead to broad-based changes in higher-level competencies such as cognitive flexibility, a core and neurally distributed component of cognition. To determine whether video gaming can enhance cognitive flexibility and, if so, why these changes occur, the current study compares two versions of a real-time strategy (RTS) game. Using a meta-analytic Bayes factor approach, we found that the gaming condition that emphasized maintenance and rapid switching between multiple information and action sources led to a large increase in cognitive flexibility as measured by a wide array of non-video gaming tasks. Theoretically, the results suggest that the distributed brain networks supporting cognitive flexibility can be tuned by engrossing video game experience that stresses maintenance and rapid manipulation of multiple information sources. Practically, these results suggest avenues for increasing cognitive function. PMID:23950921

  17. Automation tools for flexible aircraft maintenance.

    SciTech Connect

    Prentice, William J.; Drotning, William D.; Watterberg, Peter A.; Loucks, Clifford S.; Kozlowski, David M.

    2003-11-01

    This report summarizes the accomplishments of the Laboratory Directed Research and Development (LDRD) project 26546 at Sandia, during the period FY01 through FY03. The project team visited four DoD depots that support extensive aircraft maintenance in order to understand critical needs for automation, and to identify maintenance processes for potential automation or integration opportunities. From the visits, the team identified technology needs and application issues, as well as non-technical drivers that influence the application of automation in depot maintenance of aircraft. Software tools for automation facility design analysis were developed, improved, extended, and integrated to encompass greater breadth for eventual application as a generalized design tool. The design tools for automated path planning and path generation have been enhanced to incorporate those complex robot systems with redundant joint configurations, which are likely candidate designs for a complex aircraft maintenance facility. A prototype force-controlled actively compliant end-effector was designed and developed based on a parallel kinematic mechanism design. This device was developed for demonstration of surface finishing, one of many in-contact operations performed during aircraft maintenance. This end-effector tool was positioned along the workpiece by a robot manipulator, programmed for operation by the automated planning tools integrated for this project. Together, the hardware and software tools demonstrate many of the technologies required for flexible automation in a maintenance facility.

  18. Developments in flexible endoscopic surgery: a review

    PubMed Central

    Feussner, Hubertus; Becker, Valentin; Bauer, Margit; Kranzfelder, Michael; Schirren, Rebekka; Lüth, Tim; Meining, Alexander; Wilhelm, Dirk

    2015-01-01

    Flexible endoscopy is increasingly developing into a therapeutic instead of a purely diagnostic discipline. Improved visualization makes early lesions easily detectable and allows us to decide ad hoc on the required treatment. Deep enteroscopy allows the exploration of even the small bowel – for long a “white spot” for gastrointestinal endoscopy – and to perform direct treatment. Endoscopic submucosal dissection is a considerable step forward in oncologically correct endoscopic treatment of (early) malignant lesions. Though still technically challenging, it is increasingly facilitated by new manipulation techniques and tools that are being steadily optimized. Closure of wall defects and hemostasis could be improved significantly. Even the anatomy beyond the gastrointestinal wall is being explored by the therapeutic use of endoluminal ultrasound. Endosonographic-guided surgery is not only a suitable fallback solution if conventional endoscopic retrograde cholangiopancreatography fails, but even makes necrosectomy procedures, abscess drainage, and neurolysis feasible for the endoscopist. Newly developed endoscopic approaches aim at formerly distinctive surgical domains like gastroesophageal reflux disease, appendicitis, and cholecystitis. Combined endoscopic/laparoscopic interventional techniques could become the harbingers of natural orifice transluminal endoscopic surgery, whereas pure natural orifice transluminal endoscopic surgery is currently still in its beginnings. PMID:25565878

  19. Photocatalytic reactor with flexible supports

    DOEpatents

    Jacoby, William A.; Blake, Daniel M.

    1995-01-01

    Organic pollutants and bioaerosols in a gaseous stream are oxidized by exposure to light (e.g., UV light) in the presence of semiconductor catalyst particles or coatings supported on flexible strips suspended in the gaseous stream.

  20. Photocatalytic reactor with flexible supports

    DOEpatents

    Jacoby, W.A.; Blake, D.M.

    1995-09-12

    Organic pollutants and bioaerosols in a gaseous stream are oxidized by exposure to light (e.g., UV light) in the presence of semiconductor catalyst particles or coatings supported on flexible strips suspended in the gaseous stream. 3 figs.

  1. Ultra-Thin, Flexible Electronics

    NASA Technical Reports Server (NTRS)

    Holland, Brian; McPherson, Ryan; Zhang, Tan; Hou, Zhenwei; Dean, Robert; Johnson, R. Wayne; DelCastillo, Linda; Moussessian, Alina

    2008-01-01

    Thinned die can be used to realize ultra-thin flexible electronics for applications such as conformal and wearable electronics. Three techniques have been developed to achieve this goal using thinned die: die flip chip bonded onto flexible substrates, die laminated onto LCP films, and die embedded in polyimide. A key to achieving each of these techniques is the thinning of die to a thickness of 50 microns or thinner. Conventional CMP processing can be used to thin to 50 microns. At 50 microns, the active die become flexible and must be handled by temporarily bonding them to a holder die, for further processing. Once bonded face down to the holder die, the active die can be further thinned by DRIE etching the exposed backside. The thinned die can then been packaged in or on the flexible substrate.

  2. Flexible Transparent Electronic Gas Sensors.

    PubMed

    Wang, Ting; Guo, Yunlong; Wan, Pengbo; Zhang, Han; Chen, Xiaodong; Sun, Xiaoming

    2016-07-01

    Flexible and transparent electronic gas sensors capable of real-time, sensitive, and selective analysis at room-temperature, have gained immense popularity in recent years for their potential to be integrated into various smart wearable electronics and display devices. Here, recent advances in flexible transparent sensors constructed from semiconducting oxides, carbon materials, conducting polymers, and their nanocomposites are presented. The sensing material selection, sensor device construction, and sensing mechanism of flexible transparent sensors are discussed in detail. The critical challenges and future development associated with flexible and transparent electronic gas sensors are presented. Smart wearable gas sensors are believed to have great potential in environmental monitoring and noninvasive health monitoring based on disease biomarkers in exhaled gas. PMID:27276698

  3. Marine Technology: Diversity and Flexibility

    ERIC Educational Resources Information Center

    Buck, Dale R.

    1973-01-01

    Training for a specific field must reflect the diversity of that field and also remain flexible enough to accommodate fluctuations in the job market and the field, as marine technology illustrates. (Editor)

  4. Flexible solar-array mechanism

    NASA Technical Reports Server (NTRS)

    Olson, M. C.

    1972-01-01

    One of the key elements of the flexible rolled-up solar array system is a mechanism to deploy, retract, and store the flexible solar-cell arrays. The selection of components, the design of the mechanism assembly, and the tests that were performed are discussed. During 6 months in orbit, all mission objectives were satisfied, and inflight performance has shown good correlation with preflight analyses and tests.

  5. 17 CFR 180.2 - Prohibition on price manipulation.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 1 2013-04-01 2013-04-01 false Prohibition on price... PROHIBITION AGAINST MANIPULATION § 180.2 Prohibition on price manipulation. It shall be unlawful for any person, directly or indirectly, to manipulate or attempt to manipulate the price of any swap, or of...

  6. 17 CFR 180.2 - Prohibition on price manipulation.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 2 2014-04-01 2014-04-01 false Prohibition on price... (CONTINUED) PROHIBITION AGAINST MANIPULATION § 180.2 Prohibition on price manipulation. It shall be unlawful for any person, directly or indirectly, to manipulate or attempt to manipulate the price of any...

  7. Manipulators live better, but are they always parasites?

    PubMed

    Heil, Martin

    2015-09-01

    A recent study reports partner manipulation for an interaction that was considered a reward-for-defence mutualism. Secretions of lycaenid caterpillars altered ant locomotion and aggressiveness, likely by manipulating dopaminergic signalling. This study opens the question whether such manipulation is common and whether manipulation necessarily characterises an interaction as parasitism. PMID:26298610

  8. Developmental constraints on behavioural flexibility

    PubMed Central

    Holekamp, Kay E.; Swanson, Eli M.; Van Meter, Page E.

    2013-01-01

    We suggest that variation in mammalian behavioural flexibility not accounted for by current socioecological models may be explained in part by developmental constraints. From our own work, we provide examples of constraints affecting variation in behavioural flexibility, not only among individuals, but also among species and higher taxonomic units. We first implicate organizational maternal effects of androgens in shaping individual differences in aggressive behaviour emitted by female spotted hyaenas throughout the lifespan. We then compare carnivores and primates with respect to their locomotor and craniofacial adaptations. We inquire whether antagonistic selection pressures on the skull might impose differential functional constraints on evolvability of skulls and brains in these two orders, thus ultimately affecting behavioural flexibility in each group. We suggest that, even when carnivores and primates would theoretically benefit from the same adaptations with respect to behavioural flexibility, carnivores may nevertheless exhibit less behavioural flexibility than primates because of constraints imposed by past adaptations in the morphology of the limbs and skull. Phylogenetic analysis consistent with this idea suggests greater evolutionary lability in relative brain size within families of primates than carnivores. Thus, consideration of developmental constraints may help elucidate variation in mammalian behavioural flexibility. PMID:23569298

  9. Flexible metal-organic frameworks.

    PubMed

    Schneemann, A; Bon, V; Schwedler, I; Senkovska, I; Kaskel, S; Fischer, R A

    2014-08-21

    Advances in flexible and functional metal-organic frameworks (MOFs), also called soft porous crystals, are reviewed by covering the literature of the five years period 2009-2013 with reference to the early pertinent work since the late 1990s. Flexible MOFs combine the crystalline order of the underlying coordination network with cooperative structural transformability. These materials can respond to physical and chemical stimuli of various kinds in a tunable fashion by molecular design, which does not exist for other known solid-state materials. Among the fascinating properties are so-called breathing and swelling phenomena as a function of host-guest interactions. Phase transitions are triggered by guest adsorption/desorption, photochemical, thermal, and mechanical stimuli. Other important flexible properties of MOFs, such as linker rotation and sub-net sliding, which are not necessarily accompanied by crystallographic phase transitions, are briefly mentioned as well. Emphasis is given on reviewing the recent progress in application of in situ characterization techniques and the results of theoretical approaches to characterize and understand the breathing mechanisms and phase transitions. The flexible MOF systems, which are discussed, are categorized by the type of metal-nodes involved and how their coordination chemistry with the linker molecules controls the framework dynamics. Aspects of tailoring the flexible and responsive properties by the mixed component solid-solution concept are included, and as well examples of possible applications of flexible metal-organic frameworks for separation, catalysis, sensing, and biomedicine. PMID:24875583

  10. Developmental constraints on behavioural flexibility.

    PubMed

    Holekamp, Kay E; Swanson, Eli M; Van Meter, Page E

    2013-05-19

    We suggest that variation in mammalian behavioural flexibility not accounted for by current socioecological models may be explained in part by developmental constraints. From our own work, we provide examples of constraints affecting variation in behavioural flexibility, not only among individuals, but also among species and higher taxonomic units. We first implicate organizational maternal effects of androgens in shaping individual differences in aggressive behaviour emitted by female spotted hyaenas throughout the lifespan. We then compare carnivores and primates with respect to their locomotor and craniofacial adaptations. We inquire whether antagonistic selection pressures on the skull might impose differential functional constraints on evolvability of skulls and brains in these two orders, thus ultimately affecting behavioural flexibility in each group. We suggest that, even when carnivores and primates would theoretically benefit from the same adaptations with respect to behavioural flexibility, carnivores may nevertheless exhibit less behavioural flexibility than primates because of constraints imposed by past adaptations in the morphology of the limbs and skull. Phylogenetic analysis consistent with this idea suggests greater evolutionary lability in relative brain size within families of primates than carnivores. Thus, consideration of developmental constraints may help elucidate variation in mammalian behavioural flexibility. PMID:23569298

  11. Force reflecting hand controller for manipulator teleoperation

    NASA Technical Reports Server (NTRS)

    Bryfogle, Mark D.

    1991-01-01

    A force reflecting hand controller based upon a six degree of freedom fully parallel mechanism, often termed a Stewart Platform, has been designed, constructed, and tested as an integrated system with a slave robot manipulator test bed. A force reflecting hand controller comprises a kinesthetic device capable of transmitting position and orientation commands to a slave robot manipulator while simultaneously representing the environmental interaction forces of the slave manipulator back to the operator through actuators driving the hand controller mechanism. The Stewart Platform was chosen as a novel approach to improve force reflecting teleoperation because of its inherently high ratio of load generation capability to system mass content and the correspondingly high dynamic bandwidth. An additional novelty of the program was to implement closed loop force and torque control about the hand controller mechanism by equipping the handgrip with a six degree of freedom force and torque measuring cell. The mechanical, electrical, computer, and control systems are discussed and system tests are presented.

  12. Neurological complications of cervical spine manipulation.

    PubMed

    Stevinson, C; Honan, W; Cooke, B; Ernst, E

    2001-03-01

    To obtain preliminary data on neurological complications of spinal manipulation in the UK all members of the Association of British Neurologists were asked to report cases referred to them of neurological complications occurring within 24 hours of cervical spine manipulation over a 12-month period. The response rate was 74%. 24 respondents reported at least one case each, contributing to a total of about 35 cases. These included 7 cases of stroke in brainstem territory (4 with confirmation of vertebral artery dissection), 2 cases of stroke in carotid territory and 1 case of acute subdural haematoma. There were 3 cases of myelopathy and 3 of cervical radiculopathy. Concern about neurological complications following cervical spine manipulation appears to be justified. A large long-term prospective study is required to determine the scale of the hazard. PMID:11285788

  13. Cooperative control of multiple space manipulators

    NASA Astrophysics Data System (ADS)

    Nahon, M.; Angeles, J.

    The control of multi-armed robotic systems is inherently more complex than that of single-arm systems. Whereas a single manipulator can be controlled purely through positions or velocities, multiple manipulators handling a common payload must also be controlled in terms of forces. In this paper, the problem of finding force setpoints for the controller is formulated as a constrained optimization problem where the constraints are provided by the dynamics equations and the actuator capabilities. A number of potential objective functions which may be minimized are reviewed including the internal force, a norm of the vector of actuator torques and power losses in the system. These are then compared for a task in which the Special Purpose Dextrous Manipulator (SPDM) moves a payload in the absence of gravity. It is concluded that the actuator torque criterion appears to offer the worst compromise in performance, while the minimum internal force and minimum power loss criteria each have their advantages.

  14. Neurological complications of cervical spine manipulation.

    PubMed Central

    Stevinson, C; Honan, W; Cooke, B; Ernst, E

    2001-01-01

    To obtain preliminary data on neurological complications of spinal manipulation in the UK all members of the Association of British Neurologists were asked to report cases referred to them of neurological complications occurring within 24 hours of cervical spine manipulation over a 12-month period. The response rate was 74%. 24 respondents reported at least one case each, contributing to a total of about 35 cases. These included 7 cases of stroke in brainstem territory (4 with confirmation of vertebral artery dissection), 2 cases of stroke in carotid territory and 1 case of acute subdural haematoma. There were 3 cases of myelopathy and 3 of cervical radiculopathy. Concern about neurological complications following cervical spine manipulation appears to be justified. A large long-term prospective study is required to determine the scale of the hazard. PMID:11285788

  15. Ultrasonic resonator for manipulation of bacteria

    NASA Astrophysics Data System (ADS)

    Schwarz, T.; Dual, J.

    2012-05-01

    Ultrasonic manipulation is a contactless and gentle method to manipulate a large number of particles. The method presented here exploits the advantage to simultaneously move bacteria away from a surface by means of acoustic radiation forces. The device for the manipulation consists of five layers (transducer, epoxy adhesive layer, carrier, fluid, reflector), stacked like a conventional planar resonator. The resonator behavior was simulated using the transfer matrix method (TMM). Validation of the model was realized with admittance measurements performed over a wide frequency range (100 kHz - 16 MHz). The TMM-model was used to optimize frequency, layer thickness and material of the resonator in order to find a combination with a high force potential gradient pointing away from the reflector surface into the fluid. The resonator has been experimentally tested with polystyrene particles (1 μm in diameter) which revealed a good matching with the TMM-model. First preliminary tests with Salmonella Thyphimurium have been done.

  16. Chimpanzees strategically manipulate what others can see.

    PubMed

    Karg, Katja; Schmelz, Martin; Call, Josep; Tomasello, Michael

    2015-09-01

    Humans often strategically manipulate the informational access of others to their own advantage. Although chimpanzees know what others can and cannot see, it is unclear whether they can strategically manipulate others' visual access. In this study, chimpanzees were given the opportunity to save food for themselves by concealing it from a human competitor and also to get more food for themselves by revealing it to a human cooperator. When knowing that a competitor was approaching, chimpanzees kept more food hidden (left it covered) than when expecting a cooperator to approach. When the experimenter was already at the location of the hidden food, they actively revealed less food to the competitor than to the cooperator. They did not actively hide food (cover up food in the open) from the competitor, however. Chimpanzees thus strategically manipulated what another could see in order to maximize their payoffs and showed their ability to plan for future situations. PMID:25964096

  17. Manipulating cyanobacteria: Spirulina for potential CELSS diet

    NASA Technical Reports Server (NTRS)

    Tadros, Mahasin G.; Smith, Woodrow; Mbuthia, Peter; Joseph, Beverly

    1989-01-01

    Spirulina sp. as a bioregenerative photosynthetic and an edible alga for spacecraft crew in a CELSS, was characterized for the biomass yield in batch cultures, under various environmental conditions. The partitioning of the assimalitory products (proteins, carbohydrates, lipids) were manipulated by varying the environmental growth conditions. Experiments with Spirulina have shown that under stress conditions (i.e., high light 160 uE/sq m/s, temperature 38 C, nitrogen or phosphate limitation; 0.1 M sodium chloride) carbohydrates increased at the expense of proteins. In other experiments, where the growth media were sufficient in nutrients and incubated under optimum growth conditions, the total of the algal could be manipulated by growth conditions. These results support the feasibility of considering Spirulina as a subsystem in CELSS because of the ease with which its nutrient content can be manipulated.

  18. Sensing Temperatures Via Prostheses And Manipulators

    NASA Technical Reports Server (NTRS)

    Zerkus, Mike

    1991-01-01

    Proposed temperature-sensing system applies heat to (or removes heat from) human user's skin according to temperature of remote object. Used in artificial limbs and in telerobotic manipulators. In prosthetic arm and hand, sensors on tips of artificial fingers send signals to electronic control network that drives small, lightweight thermoelectric heat pump worn on back of user's shoulder. Heat pump heats or cools skin according to signals from sensors. Heat pump and control network worn like article of clothing. In manual control of remote robot, sensors placed in fingers of remote manipulator. Sensors drive, via similar electronic control network, thermoelectric heat pumps in fingers of glove worn by operator, who then has benefit of information about temperatures on manipulated object.

  19. Force reflecting hand controller for manipulator teleoperation

    NASA Astrophysics Data System (ADS)

    Bryfogle, Mark D.

    1991-12-01

    A force reflecting hand controller based upon a six degree of freedom fully parallel mechanism, often termed a Stewart Platform, has been designed, constructed, and tested as an integrated system with a slave robot manipulator test bed. A force reflecting hand controller comprises a kinesthetic device capable of transmitting position and orientation commands to a slave robot manipulator while simultaneously representing the environmental interaction forces of the slave manipulator back to the operator through actuators driving the hand controller mechanism. The Stewart Platform was chosen as a novel approach to improve force reflecting teleoperation because of its inherently high ratio of load generation capability to system mass content and the correspondingly high dynamic bandwidth. An additional novelty of the program was to implement closed loop force and torque control about the hand controller mechanism by equipping the handgrip with a six degree of freedom force and torque measuring cell. The mechanical, electrical, computer, and control systems are discussed and system tests are presented.

  20. Manipulation of the Microbiota Using Probiotics.

    PubMed

    Grimm, Verena; Riedel, Christian U

    2016-01-01

    A number of diseases are associated with alterations in the composition of the microbiota of various niches of the human body. Although, in most cases, it is unclear if these alterations are the cause or the consequence of disease, they provide a rationale for therapeutic or prophylactic manipulation of a dysbiotic microbiota. Approaches to manipulate the microbiome include administration of either live bacteria, which are underrepresented in the diseased individual, substances that aim at increasing the populations of these bacteria, or a combination of the two. This chapter summarizes the available data in therapeutic manipulation of a various diseased states including irritable bowel syndrome, inflammatory bowel disease, necrotizing enterocolitis, atopic and allergic diseases, and antibiotic-associated and infectious diarrhoea. PMID:27161354