The Design and Development of an Omni-Directional Mobile Robot Oriented to an Intelligent Manufacturing System

PubMed Central

Qian, Jun; Zi, Bin; Ma, Yangang; Zhang, Dan

2017-01-01

In order to transport materials flexibly and smoothly in a tight plant environment, an omni-directional mobile robot based on four Mecanum wheels was designed. The mechanical system of the mobile robot is made up of three separable layers so as to simplify its combination and reorganization. Each modularized wheel was installed on a vertical suspension mechanism, which ensures the moving stability and keeps the distances of four wheels invariable. The control system consists of two-level controllers that implement motion control and multi-sensor data processing, respectively. In order to make the mobile robot navigate in an unknown semi-structured indoor environment, the data from a Kinect visual sensor and four wheel encoders were fused to localize the mobile robot using an extended Kalman filter with specific processing. Finally, the mobile robot was integrated in an intelligent manufacturing system for material conveying. Experimental results show that the omni-directional mobile robot can move stably and autonomously in an indoor environment and in industrial fields. PMID:28891964

The Design and Development of an Omni-Directional Mobile Robot Oriented to an Intelligent Manufacturing System.

PubMed

Qian, Jun; Zi, Bin; Wang, Daoming; Ma, Yangang; Zhang, Dan

2017-09-10

In order to transport materials flexibly and smoothly in a tight plant environment, an omni-directional mobile robot based on four Mecanum wheels was designed. The mechanical system of the mobile robot is made up of three separable layers so as to simplify its combination and reorganization. Each modularized wheel was installed on a vertical suspension mechanism, which ensures the moving stability and keeps the distances of four wheels invariable. The control system consists of two-level controllers that implement motion control and multi-sensor data processing, respectively. In order to make the mobile robot navigate in an unknown semi-structured indoor environment, the data from a Kinect visual sensor and four wheel encoders were fused to localize the mobile robot using an extended Kalman filter with specific processing. Finally, the mobile robot was integrated in an intelligent manufacturing system for material conveying. Experimental results show that the omni-directional mobile robot can move stably and autonomously in an indoor environment and in industrial fields.

Behavior generation strategy of artificial behavioral system by self-learning paradigm for autonomous robot tasks

NASA Astrophysics Data System (ADS)

Dağlarli, Evren; Temeltaş, Hakan

2008-04-01

In this study, behavior generation and self-learning paradigms are investigated for the real-time applications of multi-goal mobile robot tasks. The method is capable to generate new behaviors and it combines them in order to achieve multi goal tasks. The proposed method is composed from three layers: Behavior Generating Module, Coordination Level and Emotion -Motivation Level. Last two levels use Hidden Markov models to manage dynamical structure of behaviors. The kinematics and dynamic model of the mobile robot with non-holonomic constraints are considered in the behavior based control architecture. The proposed method is tested on a four-wheel driven and four-wheel steered mobile robot with constraints in simulation environment and results are obtained successfully.

Formation tracker design of multiple mobile robots with wheel perturbations: adaptive output-feedback approach

NASA Astrophysics Data System (ADS)

Yoo, Sung Jin

2016-11-01

This paper presents a theoretical design approach for output-feedback formation tracking of multiple mobile robots under wheel perturbations. It is assumed that these perturbations are unknown and the linear and angular velocities of the robots are unmeasurable. First, adaptive state observers for estimating unmeasurable velocities of the robots are developed under the robots' kinematics and dynamics including wheel perturbation effects. Then, we derive a virtual-structure-based formation tracker scheme according to the observer dynamic surface design procedure. The main difficulty of the output-feedback control design is to manage the coupling problems between unmeasurable velocities and unknown wheel perturbation effects. These problems are avoided by using the adaptive technique and the function approximation property based on fuzzy logic systems. From the Lyapunov stability analysis, it is shown that point tracking errors of each robot and synchronisation errors for the desired formation converge to an adjustable neighbourhood of the origin, while all signals in the controlled closed-loop system are semiglobally uniformly ultimately bounded.

Speed Daemon: Experience-Based Mobile Robot Speed Scheduling

DTIC Science & Technology

2014-10-01

a wheeled mobile robot. Robotica , 20(2): 181–193, 2002. [7] O. Purwin and R. D‘Andrea. Trajectory generation and control for four wheeled...robot on an uneven surface. Robotica , 27(4):481–498, 2009. [9] S. Thrun, M. Montemerlo, H. Dahlkamp, D. Stavens, A. Aron, J. Diebel, P. Fong, J. Gale

Coordinated control of slip ratio for wheeled mobile robots climbing loose sloped terrain.

PubMed

Li, Zhengcai; Wang, Yang

2014-01-01

A challenging problem faced by wheeled mobile robots (WMRs) such as planetary rovers traversing loose sloped terrain is the inevitable longitudinal slip suffered by the wheels, which often leads to their deviation from the predetermined trajectory, reduced drive efficiency, and possible failures. This study investigates this problem using terramechanics analysis of the wheel-soil interaction. First, a slope-based wheel-soil interaction terramechanics model is built, and an online slip coordinated algorithm is designed based on the goal of optimal drive efficiency. An equation of state is established using the coordinated slip as the desired input and the actual slip as a state variable. To improve the robustness and adaptability of the control system, an adaptive neural network is designed. Analytical results and those of a simulation using Vortex demonstrate the significantly improved mobile performance of the WMR using the proposed control system.

A sub-target approach to the kinodynamic motion control of a wheeled mobile robot

NASA Astrophysics Data System (ADS)

Motonaka, Kimiko; Watanabe, Keigo; Maeyama, Shoichi

2018-02-01

A mobile robot with two independently driven wheels is popular, but it is difficult to stabilize it by a continuous controller with a constant gain, due to its nonholonomic property. It is guaranteed that a nonholonomic controlled object can always be converged to an arbitrary point using a switching control method or a quasi-continuous control method based on an invariant manifold in a chained form. From this, the authors already proposed a kinodynamic controller to converge the states of such a two-wheeled mobile robot to the arbitrary target position while avoiding obstacles, by combining the control based on the invariant manifold and the harmonic potential field (HPF). On the other hand, it was confirmed in the previous research that there is a case that the robot cannot avoid the obstacle because there is no enough space to converge the current state to the target state. In this paper, we propose a method that divides the final target position into some sub-target positions and moves the robot step by step, and it is confirmed by the simulation that the robot can converge to the target position while avoiding obstacles using the proposed method.

A Car Transportation System in Cooperation by Multiple Mobile Robots for Each Wheel: iCART II

NASA Astrophysics Data System (ADS)

Kashiwazaki, Koshi; Yonezawa, Naoaki; Kosuge, Kazuhiro; Sugahara, Yusuke; Hirata, Yasuhisa; Endo, Mitsuru; Kanbayashi, Takashi; Shinozuka, Hiroyuki; Suzuki, Koki; Ono, Yuki

The authors proposed a car transportation system, iCART (intelligent Cooperative Autonomous Robot Transporters), for automation of mechanical parking systems by two mobile robots. However, it was difficult to downsize the mobile robot because the length of it requires at least the wheelbase of a car. This paper proposes a new car transportation system, iCART II (iCART - type II), based on “a-robot-for-a-wheel” concept. A prototype system, MRWheel (a Mobile Robot for a Wheel), is designed and downsized less than half the conventional robot. First, a method for lifting up a wheel by MRWheel is described. In general, it is very difficult for mobile robots such as MRWheel to move to desired positions without motion errors caused by slipping, etc. Therefore, we propose a follower's motion error estimation algorithm based on the internal force applied to each follower by extending a conventional leader-follower type decentralized control algorithm for cooperative object transportation. The proposed algorithm enables followers to estimate their motion errors and enables the robots to transport a car to a desired position. In addition, we analyze and prove the stability and convergence of the resultant system with the proposed algorithm. In order to extract only the internal force from the force applied to each robot, we also propose a model-based external force compensation method. Finally, proposed methods are applied to the car transportation system, the experimental results confirm their validity.

Coordinated Control of Slip Ratio for Wheeled Mobile Robots Climbing Loose Sloped Terrain

PubMed Central

Li, Zhengcai; Wang, Yang

2014-01-01

A challenging problem faced by wheeled mobile robots (WMRs) such as planetary rovers traversing loose sloped terrain is the inevitable longitudinal slip suffered by the wheels, which often leads to their deviation from the predetermined trajectory, reduced drive efficiency, and possible failures. This study investigates this problem using terramechanics analysis of the wheel-soil interaction. First, a slope-based wheel-soil interaction terramechanics model is built, and an online slip coordinated algorithm is designed based on the goal of optimal drive efficiency. An equation of state is established using the coordinated slip as the desired input and the actual slip as a state variable. To improve the robustness and adaptability of the control system, an adaptive neural network is designed. Analytical results and those of a simulation using Vortex demonstrate the significantly improved mobile performance of the WMR using the proposed control system. PMID:25276849

Characterization Parameters for a Three Degree of Freedom Mobile Robot

DTIC Science & Technology

2013-12-01

DARc’s dimensions which contributed to the inertia, force, torque and position equa- tions. We calculated body inertia as 1.93kg·m2 and wheel inertia...separation .316 Wheel Radius Outer/Inner .127 m .085cm Wheel Mass .7055 kg Body Mass 13.542 kg Table 4.1: DAR-C Dimensions The force on each wheel...which used ackeman steering, a technique where wheels are able to rotate relative the robot body . The easiest example of a differentially steered

Two modular neuro-fuzzy system for mobile robot navigation

NASA Astrophysics Data System (ADS)

Bobyr, M. V.; Titov, V. S.; Kulabukhov, S. A.; Syryamkin, V. I.

2018-05-01

The article considers the fuzzy model for navigation of a mobile robot operating in two modes. In the first mode the mobile robot moves along a line. In the second mode, the mobile robot looks for an target in unknown space. Structural and schematic circuit of four-wheels mobile robot are presented in the article. The article describes the movement of a mobile robot based on two modular neuro-fuzzy system. The algorithm of neuro-fuzzy inference used in two modular control system for movement of a mobile robot is given in the article. The experimental model of the mobile robot and the simulation of the neuro-fuzzy algorithm used for its control are presented in the article.

Fractional Control of An Active Four-wheel-steering Vehicle

NASA Astrophysics Data System (ADS)

Wang, Tianting; Tong, Jun; Chen, Ning; Tian, Jie

2018-03-01

A four-wheel-steering (4WS) vehicle model and reference model with a drop filter are constructed. The decoupling of 4WS vehicle model is carried out. And a fractional PIλDμ controller is introduced into the decoupling strategy to reduce the effects of the uncertainty of the vehicle parameters as well as the unmodelled dynamics on the system performance. Based on optimization techniques, the design of fractional controller are obtained to ensure the robustness of 4WS vehicle during the special range of frequencies through proper choice of the constraints. In order to compare with fractional robust controller, an optimal controller for the same vehicle is also designed. The simulations of the two control systems are carried out and it reveals that the decoupling and fractional robust controller is able to make vehicle model trace the reference model very well with better robustness.

Risk of thoracic injury from direct steering wheel impact in frontal crashes.

PubMed

Chen, Rong; Gabler, Hampton C

2014-06-01

The combination of airbag and seat belt is considered to be the most effective vehicle safety system. However, despite the widespread availability of airbags and a belt use rate of more than 85%, US drivers involved in crashes continue to be at risk of serious thoracic injury. The objective of this study was to determine the influence of steering wheel deformation on driver injury risk in frontal automobile crash. The analysis is based on cases extracted from the National Automotive Sampling System Crashworthiness Data System database for case years 1993 to 2011. The approach was to compare the adjusted odds of frontal crash injury experienced by drivers in vehicles with and without steering wheel deformation. Among frontal crash cases with belted drivers, observable steering wheel deformation occurred in less than 4% of all cases but accounted for 30% of belted drivers with serious (Abbreviated Injury Scale [AIS] score, 3+) thoracic injuries. Similarly, steering wheel deformation occurred in approximately 13% of unbelted drivers but accounted for 60% of unbelted drivers with serious thoracic injuries. Belted drivers in frontal crashes with steering wheel deformation were found to have two times greater odds of serious thoracic injury. Unbelted drivers were found to have four times greater odds of serious thoracic injury in crashes with steering wheel deformation. In frontal crashes, steering wheel deformation was more likely to occur in unbelted drivers than belted drivers, as well as higher severity crashes and with heavier drivers. The results of the present study show that airbag deployment and seat belt restraint do not completely eliminate the possibility of steering wheel contact. Even with the most advanced restraint systems, there remains an opportunity for further reduction in thoracic injury by continued enhancement to the seat belt and airbag systems. Furthermore, the results showed that steering wheel deformation is an indicator of potential serious

Global Output-Feedback Control for Simultaneous Tracking and Stabilization of Wheeled Mobile Robots

NASA Astrophysics Data System (ADS)

Chang, J.; Zhang, L. J.; Xue, D.

A time-varying global output-feedback controller is presented that solves both tracking and stabilization for wheeled mobile robots simultaneously at the torque level. The controller synthesis is based on a coordinate transformation, Lyapunov direct method and backstepping technique. The performance of the proposed controller is demonstrated by simulation.

Path-following control of wheeled planetary exploration robots moving on deformable rough terrain.

PubMed

Ding, Liang; Gao, Hai-bo; Deng, Zong-quan; Li, Zhijun; Xia, Ke-rui; Duan, Guang-ren

2014-01-01

The control of planetary rovers, which are high performance mobile robots that move on deformable rough terrain, is a challenging problem. Taking lateral skid into account, this paper presents a rough terrain model and nonholonomic kinematics model for planetary rovers. An approach is proposed in which the reference path is generated according to the planned path by combining look-ahead distance and path updating distance on the basis of the carrot following method. A path-following strategy for wheeled planetary exploration robots incorporating slip compensation is designed. Simulation results of a four-wheeled robot on deformable rough terrain verify that it can be controlled to follow a planned path with good precision, despite the fact that the wheels will obviously skid and slip.

Path-Following Control of Wheeled Planetary Exploration Robots Moving on Deformable Rough Terrain

PubMed Central

Ding, Liang; Gao, Hai-bo; Deng, Zong-quan; Li, Zhijun; Xia, Ke-rui; Duan, Guang-ren

2014-01-01

The control of planetary rovers, which are high performance mobile robots that move on deformable rough terrain, is a challenging problem. Taking lateral skid into account, this paper presents a rough terrain model and nonholonomic kinematics model for planetary rovers. An approach is proposed in which the reference path is generated according to the planned path by combining look-ahead distance and path updating distance on the basis of the carrot following method. A path-following strategy for wheeled planetary exploration robots incorporating slip compensation is designed. Simulation results of a four-wheeled robot on deformable rough terrain verify that it can be controlled to follow a planned path with good precision, despite the fact that the wheels will obviously skid and slip. PMID:24790582

Intelligent mobility for robotic vehicles in the army after next

NASA Astrophysics Data System (ADS)

Gerhart, Grant R.; Goetz, Richard C.; Gorsich, David J.

1999-07-01

The TARDEC Intelligent Mobility program addresses several essential technologies necessary to support the army after next (AAN) concept. Ground forces in the AAN time frame will deploy robotic unmanned ground vehicles (UGVs) in high-risk missions to avoid exposing soldiers to both friendly and unfriendly fire. Prospective robotic systems will include RSTA/scout vehicles, combat engineering/mine clearing vehicles, indirect fire artillery and missile launch platforms. The AAN concept requires high on-road and off-road mobility, survivability, transportability/deployability and low logistics burden. TARDEC is developing a robotic vehicle systems integration laboratory (SIL) to evaluate technologies and their integration into future UGV systems. Example technologies include the following: in-hub electric drive, omni-directional wheel and steering configurations, off-road tires, adaptive tire inflation, articulated vehicles, active suspension, mine blast protection, detection avoidance and evasive maneuver. This paper will describe current developments in these areas relative to the TARDEC intelligent mobility program.

Levels of steering control: Reproduction of steering-wheel movements

NASA Technical Reports Server (NTRS)

Godthelp, H.

1982-01-01

A schematic description of the steering control process is presented. It is shown that this process can be described in terms of levels of control. Level of control will depend on driver's skill in making use of 'clever' strategies which may be related to knowledge about the path to follow (input) and/or the vehicle under control. This knowledge may be referred to as an internal model of a particular task element. Internal information, as derived from these internal models will probably be used together with proprioceptive feedback. It is hypothesized that the efficiency of the higher levels of control will be dependent on the accuracy of both the internal and proprioceptive information. Based on this research philosophy a series of experiments is carried out. Two primary experiments were done in order to analyse subjects' ability to reproduce steering-wheel positions and movements without visual feedback. Steering-wheel angle amplitude, steering force and movement frequency were involved as independent variables.

A new family of omnidirectional and holonomic wheeled platforms for mobile robots

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pin, F.G.; Killough, S.M.

1994-08-01

This paper presents the concepts for a new family of holonomic wheeled platforms that feature full omnidirectionality with simultaneous and independently controlled rotational and translational motion capabilities. The authors first present the orthogonal-wheels'' concept and the two major wheel assemblies on which these platforms are based. The authors then describe how a combination of these assemblies with appropriate control can be used to generate an omnidirectional capability for mobile robot platforms. Several alternative designs are considered, and their respective characteristics with respect to rotational and translational motion control are discussed. The design and control of a prototype platform developed tomore » test and demonstrate the proposed concepts is then described, and experimental results illustrating the full omnidirectionality of the platforms with decoupled rotational and translational degrees of freedom are presented.« less

Hopper on wheels: evolving the hopping robot concept

NASA Technical Reports Server (NTRS)

Schell, S.; Tretten, A.; Burdick, J.; Fuller, S. B.; Fiorini, P.

2001-01-01

This paper describes the evolution of our concept of hopping robot for planetary exploration, that combines coarse long range mobility achieved by hopping, with short range wheeled mobility for precision target acquisition.

Method for controlling a vehicle with two or more independently steered wheels

DOEpatents

Reister, D.B.; Unseren, M.A.

1995-03-28

A method is described for independently controlling each steerable drive wheel of a vehicle with two or more such wheels. An instantaneous center of rotation target and a tangential velocity target are inputs to a wheel target system which sends the velocity target and a steering angle target for each drive wheel to a pseudo-velocity target system. The pseudo-velocity target system determines a pseudo-velocity target which is compared to a current pseudo-velocity to determine a pseudo-velocity error. The steering angle targets and the steering angles are inputs to a steering angle control system which outputs to the steering angle encoders, which measure the steering angles. The pseudo-velocity error, the rate of change of the pseudo-velocity error, and the wheel slip between each pair of drive wheels are used to calculate intermediate control variables which, along with the steering angle targets are used to calculate the torque to be applied at each wheel. The current distance traveled for each wheel is then calculated. The current wheel velocities and steering angle targets are used to calculate the cumulative and instantaneous wheel slip and the current pseudo-velocity. 6 figures.

Asymptotic sideslip angle and yaw rate decoupling control in four-wheel steering vehicles

NASA Astrophysics Data System (ADS)

Marino, Riccardo; Scalzi, Stefano

2010-09-01

This paper shows that, for a four-wheel steering vehicle, a proportional-integral (PI) active front steering control and a PI active rear steering control from the yaw rate error together with an additive feedforward reference signal for the vehicle sideslip angle can asymptotically decouple the lateral velocity and the yaw rate dynamics; that is the control can set arbitrary steady state values for lateral speed and yaw rate at any longitudinal speed. Moreover, the PI controls can suppress oscillatory behaviours by assigning real stable eigenvalues to a widely used linearised model of the vehicle steering dynamics for any value of longitudinal speed in understeering vehicles. In particular, the four PI control parameters are explicitly expressed in terms of the three real eigenvalues to be assigned. No lateral acceleration and no lateral speed measurements are required. The controlled system maintains the well-known advantages of both front and rear active steering controls: higher controllability, enlarged bandwidth for the yaw rate dynamics, suppressed resonances, new stable cornering manoeuvres and improved manoeuvrability. In particular, zero lateral speed may be asymptotically achieved while controlling the yaw rate: in this case comfort is improved since the phase lag between lateral acceleration and yaw rate is reduced. Also zero yaw rate can be asymptotically achieved: in this case additional stable manoeuvres are obtained in obstacle avoidance. Several simulations, including step references and moose tests, are carried out on a standard small SUV CarSim model to explore the robustness with respect to unmodelled effects such as combined lateral and longitudinal tyre forces, pitch, roll and driver dynamics. The simulations confirm the decoupling between the lateral velocity and the yaw rate and show the advantages obtained by the proposed control: reduced lateral speed or reduced yaw rate, suppressed oscillations and new stable manoeuvres.

Design of a robotic vehicle with self-contained intelligent wheels

NASA Astrophysics Data System (ADS)

Poulson, Eric A.; Jacob, John S.; Gunderson, Robert W.; Abbott, Ben A.

1998-08-01

The Center for Intelligent Systems has developed a small robotic vehicle named the Advanced Rover Chassis 3 (ARC 3) with six identical intelligent wheel units attached to a payload via a passive linkage suspension system. All wheels are steerable, so the ARC 3 can move in any direction while rotating at any rate allowed by the terrain and motors. Each intelligent wheel unit contains a drive motor, steering motor, batteries, and computer. All wheel units are identical, so manufacturing, programing, and spare replacement are greatly simplified. The intelligent wheel concept would allow the number and placement of wheels on the vehicle to be changed with no changes to the control system, except to list the position of all the wheels relative to the vehicle center. The task of controlling the ARC 3 is distributed between one master computer and the wheel computers. Tasks such as controlling the steering motors and calculating the speed of each wheel relative to the vehicle speed in a corner are dependent on the location of a wheel relative to the vehicle center and ar processed by the wheel computers. Conflicts between the wheels are eliminated by computing the vehicle velocity control in the master computer. Various approaches to this distributed control problem, and various low level control methods, have been explored.

A Null Space Control of Two Wheels Driven Mobile Manipulator Using Passivity Theory

NASA Astrophysics Data System (ADS)

Shibata, Tsuyoshi; Murakami, Toshiyuki

This paper describes a control strategy of null space motion of a two wheels driven mobile manipulator. Recently, robot is utilized in various industrial fields and it is preferable for the robot manipulator to have multiple degrees of freedom motion. Several studies of kinematics for null space motion have been proposed. However stability analysis of null space motion is not enough. Furthermore, these approaches apply to stable systems, but they do not apply unstable systems. Then, in this research, base of manipulator equips with two wheels driven mobile robot. This robot is called two wheels driven mobile manipulator, which becomes unstable system. In the proposed approach, a control design of null space uses passivity based stabilizing. A proposed controller is decided so that closed-loop system of robot dynamics satisfies passivity. This is passivity based control. Then, control strategy is that stabilizing of the robot system applies to work space observer based approach and null space control while keeping end-effector position. The validity of the proposed approach is verified by simulations and experiments of two wheels driven mobile manipulator.

Adaptive tracking control of a wheeled mobile robot via an uncalibrated camera system.

PubMed

Dixon, W E; Dawson, D M; Zergeroglu, E; Behal, A

2001-01-01

This paper considers the problem of position/orientation tracking control of wheeled mobile robots via visual servoing in the presence of parametric uncertainty associated with the mechanical dynamics and the camera system. Specifically, we design an adaptive controller that compensates for uncertain camera and mechanical parameters and ensures global asymptotic position/orientation tracking. Simulation and experimental results are included to illustrate the performance of the control law.

Utah State University's T2 ODV mobility analysis

NASA Astrophysics Data System (ADS)

Davidson, Morgan E.; Bahl, Vikas; Wood, Carl G.

2000-07-01

In response to ultra-high maneuverability vehicle requirements, Utah State University (USU) has developed an autonomous vehicle with unique mobility and maneuverability capabilities. This paper describes a study of the mobility of the USU T2 Omni-Directional Vehicle (ODV). The T2 vehicle is a mid-scale (625 kg), second-generation ODV mobile robot with six independently driven and steered wheel assemblies. The six wheel, independent steering system is capable of unlimited steering rotation, presenting a unique solution to enhanced vehicle mobility requirements. This mobility study focuses on energy consumption in three basic experiments, comparing two modes of steering: Ackerman and ODV. The experiments are all performed on the same vehicle without any physical changes to the vehicle itself, providing a direct comparison these two steering methodologies. A computer simulation of the T2 mechanical and control system dynamics is described.

High-Clearance Six-Wheel Suspension

NASA Technical Reports Server (NTRS)

Bickler, Donald B.

1992-01-01

Multilevered suspension system gives body of vehicle high clearance and allows wheels to be steered independently. Suspension linkages above wheels enable body to skim over obstacles as high as wheel. Levers and independently steered wheels enable vehicle to climb steps 1 1/2 wheel diameters high and cross gaps 1 3/4 wide. Adaptable to off-the-road recreational vehicles, military scout vehicles, and robotic emergency vehicles.

Method for controlling a vehicle with two or more independently steered wheels

DOEpatents

Reister, David B.; Unseren, Michael A.

1995-01-01

A method (10) for independently controlling each steerable drive wheel (W.sub.i) of a vehicle with two or more such wheels (W.sub.i). An instantaneous center of rotation target (ICR) and a tangential velocity target (v.sup.G) are inputs to a wheel target system (30) which sends the velocity target (v.sub.i.sup.G) and a steering angle target (.theta..sub.i.sup.G) for each drive wheel (W.sub.i) to a pseudovelocity target system (32). The pseudovelocity target system (32) determines a pseudovelocity target (v.sub.P.sup.G) which is compared to a current pseudovelocity (v.sub.P.sup.m) to determine a pseudovelocity error (.epsilon.). The steering angle targets (.theta..sup.G) and the steering angles (.theta..sup.m) are inputs to a steering angle control system (34) which outputs to the steering angle encoders (36), which measure the steering angles (.theta..sup.m). The pseudovelocity error (.epsilon.), the rate of change of the pseudovelocity error ( ), and the wheel slip between each pair of drive wheels (W.sub.i) are used to calculate intermediate control variables which, along with the steering angle targets (.theta..sup.G) are used to calculate the torque to be applied at each wheel (W.sub.i). The current distance traveled for each wheel (W.sub.i) is then calculated. The current wheel velocities (v.sup.m) and steering angle targets (.theta..sup.G) are used to calculate the cumulative and instantaneous wheel slip (e, ) and the current pseudovelocity (v.sub.P.sup.m).

Identifying cognitive distraction using steering wheel reversal rates.

PubMed

Kountouriotis, Georgios K; Spyridakos, Panagiotis; Carsten, Oliver M J; Merat, Natasha

2016-11-01

The influence of driver distraction on driving performance is not yet well understood, but it can have detrimental effects on road safety. In this study, we examined the effects of visual and non-visual distractions during driving, using a high-fidelity driving simulator. The visual task was presented either at an offset angle on an in-vehicle screen, or on the back of a moving lead vehicle. Similar to results from previous studies in this area, non-visual (cognitive) distraction resulted in improved lane keeping performance and increased gaze concentration towards the centre of the road, compared to baseline driving, and further examination of the steering control metrics indicated an increase in steering wheel reversal rates, steering wheel acceleration, and steering entropy. We show, for the first time, that when the visual task is presented centrally, drivers' lane deviation reduces (similar to non-visual distraction), whilst measures of steering control, overall, indicated more steering activity, compared to baseline. When using a visual task that required the diversion of gaze to an in-vehicle display, but without a manual element, lane keeping performance was similar to baseline driving. Steering wheel reversal rates were found to adequately tease apart the effects of non-visual distraction (increase of 0.5° reversals) and visual distraction with offset gaze direction (increase of 2.5° reversals). These findings are discussed in terms of steering control during different types of in-vehicle distraction, and the possible role of manual interference by distracting secondary tasks. Copyright © 2016 Elsevier Ltd. All rights reserved.

Coordinated Control Of Mobile Robotic Manipulators

NASA Technical Reports Server (NTRS)

Seraji, Homayoun

1995-01-01

Computationally efficient scheme developed for on-line coordinated control of both manipulation and mobility of robots that include manipulator arms mounted on mobile bases. Applicable to variety of mobile robotic manipulators, including robots that move along tracks (typically, painting and welding robots), robots mounted on gantries and capable of moving in all three dimensions, wheeled robots, and compound robots (consisting of robots mounted on other robots). Theoretical basis discussed in several prior articles in NASA Tech Briefs, including "Increasing the Dexterity of Redundant Robots" (NPO-17801), "Redundant Robot Can Avoid Obstacles" (NPO-17852), "Configuration-Control Scheme Copes With Singularities" (NPO-18556), "More Uses for Configuration Control of Robots" (NPO-18607/NPO-18608).

Steering Dynamics of Tilting Narrow Track Vehicle with Passive Front Wheel Design

NASA Astrophysics Data System (ADS)

TAN, Jeffrey Too Chuan; ARAKAWA, Hiroki; SUDA, Yoshihiro

2016-09-01

In recent years, narrow track vehicle has been emerged as a potential candidate for the next generation of urban transportation system, which is greener and space effective. Vehicle body tilting has been a symbolic characteristic of such vehicle, with the purpose to maintain its stability with the narrow track body. However, the coordination between active steering and vehicle tilting requires considerable driving skill in order to achieve effective stability. In this work, we propose an alternative steering method with a passive front wheel that mechanically follows the vehicle body tilting. The objective of this paper is to investigate the steering dynamics of the vehicle under various design parameters of the passive front wheel. Modeling of a three-wheel tilting narrow track vehicle and multibody dynamics simulations were conducted to study the effects of two important front wheel design parameters, i.e. caster angle and trail toward the vehicle steering dynamics in steering response time, turning radius, steering stability and resiliency towards external disturbance. From the results of the simulation studies, we have verified the relationships of these two front wheel design parameters toward the vehicle steering dynamics.

Multi sensor fusion framework for indoor-outdoor localization of limited resource mobile robots.

PubMed

Marín, Leonardo; Vallés, Marina; Soriano, Ángel; Valera, Ángel; Albertos, Pedro

2013-10-21

This paper presents a sensor fusion framework that improves the localization of mobile robots with limited computational resources. It employs an event based Kalman Filter to combine the measurements of a global sensor and an inertial measurement unit (IMU) on an event based schedule, using fewer resources (execution time and bandwidth) but with similar performance when compared to the traditional methods. The event is defined to reflect the necessity of the global information, when the estimation error covariance exceeds a predefined limit. The proposed experimental platforms are based on the LEGO Mindstorm NXT, and consist of a differential wheel mobile robot navigating indoors with a zenithal camera as global sensor, and an Ackermann steering mobile robot navigating outdoors with a SBG Systems GPS accessed through an IGEP board that also serves as datalogger. The IMU in both robots is built using the NXT motor encoders along with one gyroscope, one compass and two accelerometers from Hitecnic, placed according to a particle based dynamic model of the robots. The tests performed reflect the correct performance and low execution time of the proposed framework. The robustness and stability is observed during a long walk test in both indoors and outdoors environments.

Real-time optical flow estimation on a GPU for a skied-steered mobile robot

NASA Astrophysics Data System (ADS)

Kniaz, V. V.

2016-04-01

Accurate egomotion estimation is required for mobile robot navigation. Often the egomotion is estimated using optical flow algorithms. For an accurate estimation of optical flow most of modern algorithms require high memory resources and processor speed. However simple single-board computers that control the motion of the robot usually do not provide such resources. On the other hand, most of modern single-board computers are equipped with an embedded GPU that could be used in parallel with a CPU to improve the performance of the optical flow estimation algorithm. This paper presents a new Z-flow algorithm for efficient computation of an optical flow using an embedded GPU. The algorithm is based on the phase correlation optical flow estimation and provide a real-time performance on a low cost embedded GPU. The layered optical flow model is used. Layer segmentation is performed using graph-cut algorithm with a time derivative based energy function. Such approach makes the algorithm both fast and robust in low light and low texture conditions. The algorithm implementation for a Raspberry Pi Model B computer is discussed. For evaluation of the algorithm the computer was mounted on a Hercules mobile skied-steered robot equipped with a monocular camera. The evaluation was performed using a hardware-in-the-loop simulation and experiments with Hercules mobile robot. Also the algorithm was evaluated using KITTY Optical Flow 2015 dataset. The resulting endpoint error of the optical flow calculated with the developed algorithm was low enough for navigation of the robot along the desired trajectory.

Simultaneous tracking and regulation visual servoing of wheeled mobile robots with uncalibrated extrinsic parameters

NASA Astrophysics Data System (ADS)

Lu, Qun; Yu, Li; Zhang, Dan; Zhang, Xuebo

2018-01-01

This paper presentsa global adaptive controller that simultaneously solves tracking and regulation for wheeled mobile robots with unknown depth and uncalibrated camera-to-robot extrinsic parameters. The rotational angle and the scaled translation between the current camera frame and the reference camera frame, as well as the ones between the desired camera frame and the reference camera frame can be calculated in real time by using the pose estimation techniques. A transformed system is first obtained, for which an adaptive controller is then designed to accomplish both tracking and regulation tasks, and the controller synthesis is based on Lyapunov's direct method. Finally, the effectiveness of the proposed method is illustrated by a simulation study.

Detecting lane departures from steering wheel signal.

PubMed

Sandström, Max; Lampsijärvi, Eetu; Holmström, Axi; Maconi, Göran; Ahmadzai, Shabana; Meriläinen, Antti; Hæggström, Edward; Forsman, Pia

2017-02-01

Current lane departure warning systems are video-based and lose data when road- and weather conditions are bad. This study sought to develop a lane departure warning algorithm based on the signal drawn from the steering wheel. The rationale is that a car-based lane departure warning system should be robust regardless of road- and weather conditions. N=34 professional driver students drove in a high-fidelity driving simulator at 80km/h for 55min every third hour during 36h of sustained wakefulness. During each driving session we logged the steering wheel- and lane position signals at 60Hz. To derive the lane position signal, we quantified the transfer function of the simulated vehicle and used it to derive the absolute lane position signal from the steering wheel signal. The Pearson correlation between the derived- and actual lane position signals was r=0.48 (based on 12,000km). Next we designed an algorithm that alerted, up to three seconds before they occurred, about upcoming lane deviations that exceeded 0.2m. The sensitivity of the algorithm was 47% and the specificity was 71%. To our knowledge this exceeds the performance of the current video-based systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

Multi Sensor Fusion Framework for Indoor-Outdoor Localization of Limited Resource Mobile Robots

PubMed Central

Marín, Leonardo; Vallés, Marina; Soriano, Ángel; Valera, Ángel; Albertos, Pedro

2013-01-01

This paper presents a sensor fusion framework that improves the localization of mobile robots with limited computational resources. It employs an event based Kalman Filter to combine the measurements of a global sensor and an inertial measurement unit (IMU) on an event based schedule, using fewer resources (execution time and bandwidth) but with similar performance when compared to the traditional methods. The event is defined to reflect the necessity of the global information, when the estimation error covariance exceeds a predefined limit. The proposed experimental platforms are based on the LEGO Mindstorm NXT, and consist of a differential wheel mobile robot navigating indoors with a zenithal camera as global sensor, and an Ackermann steering mobile robot navigating outdoors with a SBG Systems GPS accessed through an IGEP board that also serves as datalogger. The IMU in both robots is built using the NXT motor encoders along with one gyroscope, one compass and two accelerometers from Hitecnic, placed according to a particle based dynamic model of the robots. The tests performed reflect the correct performance and low execution time of the proposed framework. The robustness and stability is observed during a long walk test in both indoors and outdoors environments. PMID:24152933

Design of a novel wheeled tensegrity robot: a comparison of tensegrity concepts and a prototype for travelling air ducts.

PubMed

Carreño, Francisco; Post, Mark A

2018-01-01

Efforts in the research of tensegrity structures applied to mobile robots have recently been focused on a purely tensegrity solution to all design requirements. Locomotion systems based on tensegrity structures are currently slow and complex to control. Although wheeled locomotion provides better efficiency over distances there is no literature available on the value of wheeled methods with respect to tensegrity designs, nor on how to transition from a tensegrity structure to a fixed structure in mobile robotics. This paper is the first part of a larger study that aims to combine the flexibility, light weight, and strength of a tensegrity structure with the efficiency and simple control of a wheeled locomotion system. It focuses on comparing different types of tensegrity structure for applicability to a mobile robot, and experimentally finding an appropriate transitional region from a tensegrity structure to a conventional fixed structure on mobile robots. It applies this transitional structure to what is, to the authors' knowledge, the design of the world's first wheeled tensegrity robot that has been designed with the goal of traversing air ducts.

PD-like controller for delayed bilateral teleoperation of wheeled robots

NASA Astrophysics Data System (ADS)

Slawiñski, E.; Mut, V.; Santiago, D.

2016-08-01

This paper proposes a proportional derivative (PD)-like controller applied to the delayed bilateral teleoperation of wheeled robots with force feedback in face of asymmetric and varying-time delays. In contrast to bilateral teleoperation of manipulator robots, in these systems, there is a mismatch between the models of the master and slave (mobile robot), problem that is approached in this work, where the system stability is analysed. From this study, it is possible to infer the control parameters, depending on the time delay, necessary to assure stability. Finally, the performance of the delayed teleoperation system is evaluated through tests where a human operator drives a 3D simulator as well as a mobile robot for pushing objects.

Fully decentralized estimation and control for a modular wheeled mobile robot

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mutambara, A.G.O.; Durrant-Whyte, H.F.

2000-06-01

In this paper, the problem of fully decentralized data fusion and control for a modular wheeled mobile robot (WMR) is addressed. This is a vehicle system with nonlinear kinematics, distributed multiple sensors, and nonlinear sensor models. The problem is solved by applying fully decentralized estimation and control algorithms based on the extended information filter. This is achieved by deriving a modular, decentralized kinematic model by using plane motion kinematics to obtain the forward and inverse kinematics for a generalized simple wheeled vehicle. This model is then used in the decentralized estimation and control algorithms. WMR estimation and control is thusmore » obtained locally using reduced order models with reduced communication of information between nodes is carried out after every measurement (full rate communication), the estimates and control signals obtained at each node are equivalent to those obtained by a corresponding centralized system. Transputer architecture is used as the basis for hardware and software design as it supports the extensive communication and concurrency requirements that characterize modular and decentralized systems. The advantages of a modular WMR vehicle include scalability, application flexibility, low prototyping costs, and high reliability.« less

Training Toddlers Seated on Mobile Robots to Steer Using Force-Feedback Joystick.

PubMed

Agrawal, S K; Xi Chen; Ragonesi, C; Galloway, J C

2012-01-01

The broader goal of our research is to train infants with special needs to safely and purposefully drive a mobile robot to explore the environment. The hypothesis is that these impaired infants will benefit from mobility in their early years and attain childhood milestones, similar to their healthy peers. In this paper, we present an algorithm and training method using a force-feedback joystick with an "assist-as-needed" paradigm for driving training. In this "assist-as-needed" approach, if the child steers the joystick outside a force tunnel centered on the desired direction, the driver experiences a bias force on the hand. We show results with a group study on typically developing toddlers that such a haptic guidance algorithm is superior to training with a conventional joystick. We also provide a case study on two special needs children, under three years old, who learn to make sharp turns during driving, when trained over a five-day period with the force-feedback joystick using the algorithm.

Teleautonomous guidance for mobile robots

NASA Technical Reports Server (NTRS)

Borenstein, J.; Koren, Y.

1990-01-01

Teleautonomous guidance (TG), a technique for the remote guidance of fast mobile robots, has been developed and implemented. With TG, the mobile robot follows the general direction prescribed by an operator. However, if the robot encounters an obstacle, it autonomously avoids collision with that obstacle while trying to match the prescribed direction as closely as possible. This type of shared control is completely transparent and transfers control between teleoperation and autonomous obstacle avoidance gradually. TG allows the operator to steer vehicles and robots at high speeds and in cluttered environments, even without visual contact. TG is based on the virtual force field (VFF) method, which was developed earlier for autonomous obstacle avoidance. The VFF method is especially suited to the accommodation of inaccurate sensor data (such as that produced by ultrasonic sensors) and sensor fusion, and allows the mobile robot to travel quickly without stopping for obstacles.

Robot-Assisted Needle Steering

PubMed Central

Reed, Kyle B.; Majewicz, Ann; Kallem, Vinutha; Alterovitz, Ron; Goldberg, Ken; Cowan, Noah J.; Okamura, Allison M.

2012-01-01

Needle insertion is a critical aspect of many medical treatments, diagnostic methods, and scientific studies, and is considered to be one of the simplest and most minimally invasive medical procedures. Robot-assisted needle steering has the potential to improve the effectiveness of existing medical procedures and enable new ones by allowing increased accuracy through more dexterous control of the needle tip path and acquisition of targets not accessible by straight-line trajectories. In this article, we describe a robot-assisted needle steering system that uses three integrated controllers: a motion planner concerned with guiding the needle around obstacles to a target in a desired plane, a planar controller that maintains the needle in the desired plane, and a torsion compensator that controls the needle tip orientation about the axis of the needle shaft. Experimental results from steering an asymmetric-tip needle in artificial tissue demonstrate the effectiveness of the system and its sensitivity to various environmental and control parameters. In addition, we show an example of needle steering in ex vivo biological tissue to accomplish a clinically relevant task, and highlight challenges of practical needle steering implementation. PMID:23028210

Modular Robotic Vehicle

NASA Technical Reports Server (NTRS)

Borroni-Bird, Christopher E. (Inventor); Lapp, Anthony Joseph (Inventor); Vitale, Robert L. (Inventor); Lee, Chunhao J. (Inventor); Bluethmann, William J. (Inventor); Ridley, Justin S. (Inventor); Junkin, Lucien Q. (Inventor); Ambrose, Robert O. (Inventor); Lutz, Jonathan J. (Inventor); Guo, Raymond (Inventor)

2015-01-01

A modular robotic vehicle includes a chassis, driver input devices, an energy storage system (ESS), a power electronics module (PEM), modular electronic assemblies (eModules) connected to the ESS via the PEM, one or more master controllers, and various embedded controllers. Each eModule includes a drive wheel containing a propulsion-braking module, and a housing containing propulsion and braking control assemblies with respective embedded propulsion and brake controllers, and a mounting bracket covering a steering control assembly with embedded steering controllers. The master controller, which is in communication with each eModule and with the driver input devices, communicates with and independently controls each eModule, by-wire, via the embedded controllers to establish a desired operating mode. Modes may include a two-wheel, four-wheel, diamond, and omni-directional steering modes as well as a park mode. A bumper may enable docking with another vehicle, with shared control over the eModules of the vehicles.

Lyapunov vector function method in the motion stabilisation problem for nonholonomic mobile robot

NASA Astrophysics Data System (ADS)

Andreev, Aleksandr; Peregudova, Olga

2017-07-01

In this paper we propose a sampled-data control law in the stabilisation problem of nonstationary motion of nonholonomic mobile robot. We assume that the robot moves on a horizontal surface without slipping. The dynamical model of a mobile robot is considered. The robot has one front free wheel and two rear wheels which are controlled by two independent electric motors. We assume that the controls are piecewise constant signals. Controller design relies on the backstepping procedure with the use of Lyapunov vector-function method. Theoretical considerations are verified by numerical simulation.

Mobility of lightweight robots over snow

NASA Astrophysics Data System (ADS)

Lever, James H.; Shoop, Sally A.

2006-05-01

Snowfields are challenging terrain for lightweight (<50 kg) unmanned ground vehicles. Deep sinkage, high snowcompaction resistance, traction loss while turning and ingestion of snow into the drive train can cause immobility within a few meters of travel. However, for suitably designed vehicles, deep snow offers a smooth, uniform surface that can obliterate obstacles. Key requirements for good over-snow mobility are low ground pressure, large clearance relative to vehicle size and a drive system that tolerates cohesive snow. A small robot will invariably encounter deep snow relative to its ground clearance. Because a single snowstorm can easily deposit 30 cm of fresh snow, robots with ground clearance less than about 10 cm must travel over the snow rather than gain support from the underlying ground. This can be accomplished using low-pressure tracks (< 1.5 kPa). Even still, snow-compaction resistance can exceed 20% of vehicle weight. Also, despite relatively high traction coefficients for low track pressures, differential or skid steering is difficult because the outboard track can easily break traction as the vehicle attempts to turn against the snow. Short track lengths (relative to track separation) or coupled articulated robots offer steering solutions for deep snow. This paper presents preliminary guidance to design lightweight robots for good mobility over snow based on mobility theory and tests of PackBot, Talon and SnoBot, a custom-designed research robot. Because many other considerations constrain robot designs, this guidance can help with development of winterization kits to improve the over-snow performance of existing robots.

Determination of Steering Wheel Angles during CAR Alignment by Image Analysis Methods

NASA Astrophysics Data System (ADS)

Mueller, M.; Voegtle, T.

2016-06-01

Optical systems for automatic visual inspections are of increasing importance in the field of automation in the industrial domain. A new application is the determination of steering wheel angles during wheel track setting of the final inspection of car manufacturing. The camera has to be positioned outside the car to avoid interruptions of the processes and therefore, oblique images of the steering wheel must be acquired. Three different approaches of computer vision are considered in this paper, i.e. a 2D shape-based matching (by means of a plane to plane rectification of the oblique images and detection of a shape model with a particular rotation), a 3D shape-based matching approach (by means of a series of different perspectives of the spatial shape of the steering wheel derived from a CAD design model) and a point-to-point matching (by means of the extraction of significant elements (e.g. multifunctional buttons) of a steering wheel and a pairwise connection of these points to straight lines). The HALCON system (HALCON, 2016) was used for all software developments and necessary adaptions. As reference a mechanical balance with an accuracy of 0.1° was used. The quality assessment was based on two different approaches, a laboratory test and a test during production process. In the laboratory a standard deviation of ±0.035° (2D shape-based matching), ±0.12° (3D approach) and ±0.029° (point-to-point matching) could be obtained. The field test of 291 measurements (27 cars with varying poses and angles of the steering wheel) results in a detection rate of 100% and ±0.48° (2D matching) and ±0.24° (point-to-point matching). Both methods also fulfil the request of real time processing (three measurements per second).

Robotic Two-Wheeled Vehicle

NASA Technical Reports Server (NTRS)

Edlund, Jeffrey E. (Inventor); Burdick, Joel (Inventor); Abad-Manterola, Pablo (Inventor); Matthews, Jaret B. (Inventor); Nesnas, Issa A. D. (Inventor)

2014-01-01

A robotic two-wheeled vehicle comprising a connection body interposed between the two wheels are described. A drum can be coaxially located in a central region of the connection body and can support a hollow arm projecting radially from the drum. A tether can be inserted in the arm and connected to a second drum. Instruments and sensors can be accommodated in a case housed inside each wheel.

Robotic Two-Wheeled Vehicle

NASA Technical Reports Server (NTRS)

Nesnas, Issa A. D. (Inventor); Matthews, Jaret B. (Inventor); Edlund, Jeffrey E. (Inventor); Burdick, Joel (Inventor); Abad-Manterola, Pablo (Inventor)

2013-01-01

A robotic two-wheeled vehicle comprising a connection body interposed between the two wheels are described. A drum can be coaxially located in a central region of the connection body and can support a hollow arm projecting radially from the drum. A tether can be inserted in the arm and connected to a second drum. Instruments and sensors can be accommodated in a case housed inside each wheel.

Mobility Systems For Robotic Vehicles

NASA Astrophysics Data System (ADS)

Chun, Wendell

1987-02-01

The majority of existing robotic systems can be decomposed into five distinct subsystems: locomotion, control/man-machine interface (MMI), sensors, power source, and manipulator. When designing robotic vehicles, there are two main requirements: first, to design for the environment and second, for the task. The environment can be correlated with known missions. This can be seen by analyzing existing mobile robots. Ground mobile systems are generally wheeled, tracked, or legged. More recently, underwater vehicles have gained greater attention. For example, Jason Jr. made history by surveying the sunken luxury liner, the Titanic. The next big surge of robotic vehicles will be in space. This will evolve as a result of NASA's commitment to the Space Station. The foreseeable robots will interface with current systems as well as standalone, free-flying systems. A space robotic vehicle is similar to its underwater counterpart with very few differences. Their commonality includes missions and degrees-of-freedom. The issues of stability and communication are inherent in both systems and environment.

Biomechanics of liver injury by steering wheel loading.

PubMed

Lau, I V; Horsch, J D; Viano, D C; Andrzejak, D V

1987-03-01

Abdominal injury induced by steering wheel contact at a velocity of 32 km/hr was investigated using anesthetized swine as the surrogate on a Hyge sled. The lower rim of the wheel was positioned 5 cm below the xyphoid. By varying wheel stiffness, wheel orientation, and column angle, resultant abdominal injury ranged from fatal or critical to minor or none. Wheel stiffness was found to be the primary determinant of abdominal injury severity. The mechanism of abdominal injury was identified to be the rim impacting the abdomen and exceeding a combined velocity and compression sensitive tolerance limit. Abdominal injury occurred within the initial 15 ms of wheel contact before whole body movement of the surrogate of column compression, which were initiated by hub contact with the thorax. The severity of abdominal injury correlated with the peak viscous response which can be represented by the product of the instantaneous velocity of abdominal deformation and abdominal compression. It did not correlate with spinal acceleration.

Autonomous Shepherding Behaviors of Multiple Target Steering Robots.

PubMed

Lee, Wonki; Kim, DaeEun

2017-11-25

This paper presents a distributed coordination methodology for multi-robot systems, based on nearest-neighbor interactions. Among many interesting tasks that may be performed using swarm robots, we propose a biologically-inspired control law for a shepherding task, whereby a group of external agents drives another group of agents to a desired location. First, we generated sheep-like robots that act like a flock. We assume that each agent is capable of measuring the relative location and velocity to each of its neighbors within a limited sensing area. Then, we designed a control strategy for shepherd-like robots that have information regarding where to go and a steering ability to control the flock, according to the robots' position relative to the flock. We define several independent behavior rules; each agent calculates to what extent it will move by summarizing each rule. The flocking sheep agents detect the steering agents and try to avoid them; this tendency leads to movement of the flock. Each steering agent only needs to focus on guiding the nearest flocking agent to the desired location. Without centralized coordination, multiple steering agents produce an arc formation to control the flock effectively. In addition, we propose a new rule for collecting behavior, whereby a scattered flock or multiple flocks are consolidated. From simulation results with multiple robots, we show that each robot performs actions for the shepherding behavior, and only a few steering agents are needed to control the whole flock. The results are displayed in maps that trace the paths of the flock and steering robots. Performance is evaluated via time cost and path accuracy to demonstrate the effectiveness of this approach.

Path optimisation of a mobile robot using an artificial neural network controller

NASA Astrophysics Data System (ADS)

Singh, M. K.; Parhi, D. R.

2011-01-01

This article proposed a novel approach for design of an intelligent controller for an autonomous mobile robot using a multilayer feed forward neural network, which enables the robot to navigate in a real world dynamic environment. The inputs to the proposed neural controller consist of left, right and front obstacle distance with respect to its position and target angle. The output of the neural network is steering angle. A four layer neural network has been designed to solve the path and time optimisation problem of mobile robots, which deals with the cognitive tasks such as learning, adaptation, generalisation and optimisation. A back propagation algorithm is used to train the network. This article also analyses the kinematic design of mobile robots for dynamic movements. The simulation results are compared with experimental results, which are satisfactory and show very good agreement. The training of the neural nets and the control performance analysis has been done in a real experimental setup.

Four-wheeled walker related injuries in older adults in the Netherlands.

PubMed

van Riel, K M M; Hartholt, K A; Panneman, M J M; Patka, P; van Beeck, E F; van der Cammen, T J M

2014-02-01

With ageing populations worldwide, mobility devices are used more than ever. In the current literature there is no consensus whether the available mobility devices safely improve the mobility of their users. Also, evidence is lacking concerning the risks and types of injuries sustained while using a four-wheeled walker. To assess injury risks and injury patterns in older adults (≥65 years) who presented at Emergency Departments (ED) in the Netherlands with an injury due to using a four-wheeled walker. In this study, the Dutch Injury Surveillance System was used to obtain a national representative sample of annual ED visits in the Netherlands in the adult population (≥65 years) sustaining an injury while using a four-wheeled walker. The numbers of four-wheeled walker users in the Netherlands were obtained from the national insurance board. The numbers of ED visits were divided by the numbers of four-wheeled walker users to calculate age- and sex-specific injury risks. Annually 1869 older adults visited an ED after sustaining an injury while using a four-wheeled walker. Falls were the main cause of injury (96%). The injury risk was 3.1 per 100 users of four-wheeled walkers. Women (3.5 per 100 users) had a higher risk than men (2.0 per 100 users). Injury risk was the highest in women aged 85 years and older (6.2 per 100 users). The majority of injuries were fractures (60%) with hip fracture (25%) being the most common injury. Nearly half of all four-wheeled walker related injuries required hospitalisation, mostly due to hip fractures. Healthcare costs per injury were approximately €12 000. This study presents evidence that older adults experiencing a fall while using a four-wheeled walker are at high risk to suffer severe injuries.

Autonomous Shepherding Behaviors of Multiple Target Steering Robots

PubMed Central

Lee, Wonki; Kim, DaeEun

2017-01-01

This paper presents a distributed coordination methodology for multi-robot systems, based on nearest-neighbor interactions. Among many interesting tasks that may be performed using swarm robots, we propose a biologically-inspired control law for a shepherding task, whereby a group of external agents drives another group of agents to a desired location. First, we generated sheep-like robots that act like a flock. We assume that each agent is capable of measuring the relative location and velocity to each of its neighbors within a limited sensing area. Then, we designed a control strategy for shepherd-like robots that have information regarding where to go and a steering ability to control the flock, according to the robots’ position relative to the flock. We define several independent behavior rules; each agent calculates to what extent it will move by summarizing each rule. The flocking sheep agents detect the steering agents and try to avoid them; this tendency leads to movement of the flock. Each steering agent only needs to focus on guiding the nearest flocking agent to the desired location. Without centralized coordination, multiple steering agents produce an arc formation to control the flock effectively. In addition, we propose a new rule for collecting behavior, whereby a scattered flock or multiple flocks are consolidated. From simulation results with multiple robots, we show that each robot performs actions for the shepherding behavior, and only a few steering agents are needed to control the whole flock. The results are displayed in maps that trace the paths of the flock and steering robots. Performance is evaluated via time cost and path accuracy to demonstrate the effectiveness of this approach. PMID:29186836

Automated Robot Movement in the Mapped Area Using Fuzzy Logic for Wheel Chair Application

NASA Astrophysics Data System (ADS)

Siregar, B.; Efendi, S.; Ramadhana, H.; Andayani, U.; Fahmi, F.

2018-03-01

The difficulties of the disabled to move make them unable to live independently. People with disabilities need supporting device to move from place to place. For that, we proposed a solution that can help people with disabilities to move from one room to another automatically. This study aims to create a wheelchair prototype in the form of a wheeled robot as a means to learn the automatic mobilization. The fuzzy logic algorithm was used to determine motion direction based on initial position, ultrasonic sensors reading in avoiding obstacles, infrared sensors reading as a black line reader for the wheeled robot to move smooth and smartphone as a mobile controller. As a result, smartphones with the Android operating system can control the robot using Bluetooth. Here Bluetooth technology can be used to control the robot from a maximum distance of 15 meters. The proposed algorithm was able to work stable for automatic motion determination based on initial position, and also able to modernize the wheelchair movement from one room to another automatically.

Research on Walking Wheel Slippage Control of Live Inspection Robot

NASA Astrophysics Data System (ADS)

Yan, Yu; Liu, Xiaqing; Guo, Hao; Li, Jinliang; Liu, Lanlan

2017-07-01

To solve the problem of walking wheel slippage of a live inspection robot during walking or climbing, this paper analyzes the climbing capacity of the robot with a statics method, designs a pressing wheel mechanism, and presents a method of indirectly identifying walking wheel slippage by reading speed of the pressing wheel due to the fact that the linear speed of the pressing wheel and the walking wheel at the contract point is the same; and finds that the slippage state can not be controlled through accurate mathematical models after identifying the slippage state, whereas slippage can be controlled with fuzzy control. The experiment results indicate that due to design of the pressing wheel mechanism, friction force of the walking wheel is increased, and the climbing capability of the robot is improved. Within the range of climbing capability of the robot, gradient is the key factor that has influence on slippage of robot, and slippage can be effectively eliminated through the fuzzy control method proposed in this paper.

Autonomous mobile robot research using the HERMIES-III robot

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pin, F.G.; Beckerman, M.; Spelt, P.F.

1989-01-01

This paper reports on the status and future directions in the research, development and experimental validation of intelligent control techniques for autonomous mobile robots using the HERMIES-III robot at the Center for Engineering Systems Advanced research (CESAR) at Oak Ridge National Laboratory (ORNL). HERMIES-III is the fourth robot in a series of increasingly more sophisticated and capable experimental test beds developed at CESAR. HERMIES-III is comprised of a battery powered, onmi-directional wheeled platform with a seven degree-of-freedom manipulator arm, video cameras, sonar range sensors, laser imaging scanner and a dual computer system containing up to 128 NCUBE nodes in hypercubemore » configuration. All electronics, sensors, computers, and communication equipment required for autonomous operation of HERMIES-III are located on board along with sufficient battery power for three to four hours of operation. The paper first provides a more detailed description of the HERMIES-III characteristics, focussing on the new areas of research and demonstration now possible at CESAR with this new test-bed. The initial experimental program is then described with emphasis placed on autonomous performance of human-scale tasks (e.g., valve manipulation, use of tools), integration of a dexterous manipulator and platform motion in geometrically complex environments, and effective use of multiple cooperating robots (HERMIES-IIB and HERMIES- III). The paper concludes with a discussion of the integration problems and safety considerations necessarily arising from the set-up of an experimental program involving human-scale, multi-autonomous mobile robots performance. 10 refs., 3 figs.« less

Proposal to use vibration analysis steering components and car body to monitor, for example, the state of unbalance wheel

NASA Astrophysics Data System (ADS)

Janczur, R.

2016-09-01

The results of road tests of car VW Passat equipped with tires of size 195/65 R15, on the influence of the unbalancing front wheel on vibration of the parts of steering system, steering wheel and the body of the vehicle have been presented in this paper. Unbalances wheels made using weights of different masses, placed close to the outer edge of the steel rim and checked on the machine Hunter GSP 9700 for balancing wheels. The recorded waveforms vibration steering components and car body, at different constant driving speeds, subjected to spectral analysis to determine the possibility of isolating vibration caused by unbalanced wheel in various states and coming from good quality asphalt road surface. The results were discussed in terms of the possibility of identifying the state of unbalancing wheels and possible changes in radial stiffness of the tire vibration transmitted through the system driving wheel on the steering wheel. Vibration analysis steering components and car body, also in the longitudinal direction, including information from the CAN bus of the state of motion of the car, can be used to monitor the development of the state of unbalance wheel, tire damage or errors shape of brake discs or brake drums, causing pulsations braking forces.

Reliability of Heart Rate Variability Analysis by Using Electrocardiogram Recorded Unrestrainedly from an Automobile Steering-Wheel

NASA Astrophysics Data System (ADS)

Osaka, Motohisa; Murata, Hiroshige; Tateoka, Katsuhiko; Katoh, Takao

2007-07-01

Some cases of traffic accidents are assumed to be due to the occurrences of cardiac events during driving, which are thought to be induced by imbalance of autonomic nervous activities. These can be measured by analyzing heart rate variability. Therefore, we developed a new system of steering-wheel electrocardiogram with a soft-ware to remove noises. We compared the trends of sympathetic and parasympathetic nerve activities measured from the steering-wheel electrocardiograms with those recorded simultaneously from chest leads. For each parameter of instantaneous heart rate, low- or high-frequency component of heart rate variability in all the cases, the trend from the steering-wheel electrocardiogram resembled that from the chest-lead electrocardiogram. In 3 of 7 subjects, the trend of LF/HF showed a strong relationship between the steering-wheel electrocardiogram and the chest-lead electrocardiogram. Our system will open doors to a new strategy to keep a driver out of a risk by notifying it while driving.

Kinematic evaluation of mobile robotic platforms for overground gait neurorehabilitation

NASA Astrophysics Data System (ADS)

Alias, N. Akmal; Huq, M. Saiful; Ibrahim, B. S. K. K.; Omar, Rosli

2017-09-01

Gait assistive devices offer a great solution to the walking re-education which reduce patients theoretical limit by aiding the anatomical joints to be in line with the rehabilitation session. Overground gait training, which is differs significantly from body-weight supported treadmill training in many aspects, essentially consists of a mobile robotic base to support the subject securely (usually with overhead harness) while its motion and orientation is controlled seamlessly to facilitate subjects free movement. In this study, efforts have been made for evaluation of both holonomic and nonholonomic drives, the outcome of which may constitute the primarily results to the effective approach in designing a robotic platform for the mobile rehabilitation robot. The sets of kinematic equations are derived using typical geometries of two different drives. The results indicate that omnidirectional mecanum wheel platform is capable for more sophisticated discipline. Although the differential drive platform happens to be more simple and easy to construct, but it is less desirable as it has limited number of motions applicable to the system. The omnidirectional robot consisting of mecanum wheels, which is classified as holonomic is potentially the best solution in terms of its capability to move in arbitrary direction without concerning the changing of wheel's direction.

14 CFR 25.499 - Nose-wheel yaw and steering.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Nose-wheel yaw and steering. 25.499 Section 25.499 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... inertia forces. (d) For other than the nose gear, its attaching structure, and the forward fuselage...

Control of a Wheeled Transport Robot with Two Steerable Wheels

NASA Astrophysics Data System (ADS)

Larin, V. B.

2017-09-01

The control of a system with one actuator failed is studied. The problem of control of a wheeled transport robot with two steerable wheels of which the rear one is stuck (its drive has failed) is solved. An algorithm for controlling the system in this situation is proposed. The effectiveness of the algorithm is demonstrated by way of an example.

A dragline-forming mobile robot inspired by spiders.

PubMed

Wang, Liyu; Culha, Utku; Iida, Fumiya

2014-03-01

Mobility of wheeled or legged machines can be significantly increased if they are able to move from a solid surface into a three-dimensional space. Although that may be achieved by addition of flying mechanisms, the payload fraction will be the limiting factor in such hybrid mobile machines for many applications. Inspired by spiders producing draglines to assist locomotion, the paper proposes an alternative mobile technology where a robot achieves locomotion from a solid surface into a free space. The technology resembles the dragline production pathway in spiders to a technically feasible degree and enables robots to move with thermoplastic spinning of draglines. As an implementation, a mobile robot has been prototyped with thermoplastic adhesives as source material of the draglines. Experimental results show that a dragline diameter range of 1.17-5.27 mm was achievable by the 185 g mobile robot in descending locomotion from the solid surface of a hanging structure with a power consumption of 4.8 W and an average speed of 5.13 cm min(-1). With an open-loop controller consisting of sequences of discrete events, the robot has demonstrated repeatable dragline formation with a relative deviation within -4% and a length close to the metre scale.

System design of a hand-held mobile robot for craniotomy.

PubMed

Kane, Gavin; Eggers, Georg; Boesecke, Robert; Raczkowsky, Jörg; Wörn, Heinz; Marmulla, Rüdiger; Mühling, Joachim

2009-01-01

This contribution reports the development and initial testing of a Mobile Robot System for Surgical Craniotomy, the Craniostar. A kinematic system based on a unicycle robot is analysed to provide local positioning through two spiked wheels gripping directly onto a patients skull. A control system based on a shared control system between both the Surgeon and Robot is employed in a hand-held design that is tested initially on plastic phantom and swine skulls. Results indicate that the system has substantially lower risk than present robotically assisted craniotomies, and despite being a hand-held mobile robot, the Craniostar is still capable of sub-millimetre accuracy in tracking along a trajectory and thus achieving an accurate transfer of pre-surgical plan to the operating room procedure, without the large impact of current medical robots based on modified industrial robots.

Decoupling control of steering and driving system for in-wheel-motor-drive electric vehicle

NASA Astrophysics Data System (ADS)

Zhang, Han; Zhao, Wanzhong

2018-02-01

To improve the maneuverability and stability of in-wheel-motor-drive electric vehicle, a control strategy based on nonlinear decoupling control method is proposed in this paper, realizing the coordinated control of the steering and driving system. At first, the nonlinear models of the in-wheel-motor-drive electric vehicle and its sub-system are constructed. Then the inverse system decoupling theory is applied to decompose the nonlinear system into several independent subsystems, which makes it possible to realize the coordinated control of each subsystem. Next, the μ-Synthesis theory is applied to eliminate the influence of model uncertainty, improving the stability, robustness and tracking performance of in-wheel-motor-drive electric vehicle. Simulation and experiment results and numerical analyses, based on the electric vehicle actuated by in-wheel-motors, prove that the proposed control method is effective to accomplish the decoupling control of the steering and driving system in both simulation and real practice.

Advanced emergency braking under split friction conditions and the influence of a destabilising steering wheel torque

NASA Astrophysics Data System (ADS)

Tagesson, Kristoffer; Cole, David

2017-07-01

The steering system in most heavy trucks is such that it causes a destabilising steering wheel torque when braking on split friction, that is, different friction levels on the two sides of the vehicle. Moreover, advanced emergency braking systems are now mandatory in most heavy trucks, making vehicle-induced split friction braking possible. This imposes higher demands on understanding how the destabilising steering wheel torque affects the driver, which is the focus here. Firstly, an experiment has been carried out involving 24 subjects all driving a truck where automatic split friction braking was emulated. Secondly, an existing driver-vehicle model has been adapted and implemented to improve understanding of the observed outcome. A common conclusion drawn, after analysing results, is that the destabilising steering wheel torque only has a small effect on the motion of the vehicle. The underlying reason is a relatively slow ramp up of the disturbance in comparison to the observed cognitive delay amongst subjects; also the magnitude is low and initially suppressed by passive driver properties.

Effect of drivers' age and push button locations on visual time off road, steering wheel deviation and safety perception.

PubMed

Dukic, T; Hanson, L; Falkmer, T

2006-01-15

The study examined the effects of manual control locations on two groups of randomly selected young and old drivers in relation to visual time off road, steering wheel deviation and safety perception. Measures of visual time off road, steering wheel deviations and safety perception were performed with young and old drivers during real traffic. The results showed an effect of both driver's age and button location on the dependent variables. Older drivers spent longer visual time off road when pushing the buttons and had larger steering wheel deviations. Moreover, the greater the eccentricity between the normal line of sight and the button locations, the longer the visual time off road and the larger the steering wheel deviations. No interaction effect between button location and age was found with regard to visual time off road. Button location had an effect on perceived safety: the further away from the normal line of sight the lower the rating.

Improving mobile robot localization: grid-based approach

NASA Astrophysics Data System (ADS)

Yan, Junchi

2012-02-01

Autonomous mobile robots have been widely studied not only as advanced facilities for industrial and daily life automation, but also as a testbed in robotics competitions for extending the frontier of current artificial intelligence. In many of such contests, the robot is supposed to navigate on the ground with a grid layout. Based on this observation, we present a localization error correction method by exploring the geometric feature of the tile patterns. On top of the classical inertia-based positioning, our approach employs three fiber-optic sensors that are assembled under the bottom of the robot, presenting an equilateral triangle layout. The sensor apparatus, together with the proposed supporting algorithm, are designed to detect a line's direction (vertical or horizontal) by monitoring the grid crossing events. As a result, the line coordinate information can be fused to rectify the cumulative localization deviation from inertia positioning. The proposed method is analyzed theoretically in terms of its error bound and also has been implemented and tested on a customary developed two-wheel autonomous mobile robot.

Autonomous mobile robotic system for supporting counterterrorist and surveillance operations

NASA Astrophysics Data System (ADS)

Adamczyk, Marek; Bulandra, Kazimierz; Moczulski, Wojciech

2017-10-01

Contemporary research on mobile robots concerns applications to counterterrorist and surveillance operations. The goal is to develop systems that are capable of supporting the police and special forces by carrying out such operations. The paper deals with a dedicated robotic system for surveillance of large objects such as airports, factories, military bases, and many others. The goal is to trace unauthorised persons who try to enter to the guarded area, document the intrusion and report it to the surveillance centre, and then warn the intruder by sound messages and eventually subdue him/her by stunning through acoustic effect of great power. The system consists of several parts. An armoured four-wheeled robot assures required mobility of the system. The robot is equipped with a set of sensors including 3D mapping system, IR and video cameras, and microphones. It communicates with the central control station (CCS) by means of a wideband wireless encrypted system. A control system of the robot can operate autonomously, and under remote control. In the autonomous mode the robot follows the path planned by the CCS. Once an intruder has been detected, the robot can adopt its plan to allow tracking him/her. Furthermore, special procedures of treatment of the intruder are applied including warning about the breach of the border of the protected area, and incapacitation of an appropriately selected very loud sound until a patrol of guards arrives. Once getting stuck the robot can contact the operator who can remotely solve the problem the robot is faced with.

Four-Wheel Vehicle Suspension System

NASA Technical Reports Server (NTRS)

Bickler, Donald B.

1990-01-01

Four-wheel suspension system uses simple system of levers with no compliant components to provide three-point suspension of chassis of vehicle while maintaining four-point contact with uneven terrain. Provides stability against tipping of four-point rectangular base, without rocking contact to which rigid four-wheel frame susceptible. Similar to six-wheel suspension system described in "Articulated Suspension Without Springs" (NPO-17354).

Apparent mass of the human body in the vertical direction: Effect of a footrest and a steering wheel

NASA Astrophysics Data System (ADS)

Toward, M. G. R.; Griffin, M. J.

2010-04-01

The apparent mass of the seated human body influences the vibration transmitted through a car seat. The apparent mass of the body is known to be influenced by sitting posture but the influence of the position of the hands and the feet is not well understood. This study was designed to quantify the influence of steering wheel location and the position of a footrest on the vertical apparent mass of the human body. The influences of the forces applied by the hands to a steering wheel and by the feet to a footrest were also investigated. Twelve subjects were exposed to whole-body vertical random vibration (1.0 m s -2 rms over the frequency range 0.13-40.0 Hz) while supported by a rigid seat with a backrest reclined to 15°. The apparent mass of the body was measured with five horizontal positions and three vertical positions of a steering wheel and also with hands in the lap, and with five horizontal positions of a footrest. The influence of five forward forces (0, 50, 100, 150, 200 N) applied separately to the 'steering wheel' and the footrest were also investigated as well as a 'no backrest' condition. With their hands in their laps, subjects exhibited a resonance around 6.7 Hz, compared to 4.8 Hz when sitting upright with no backrest. In the same posture holding a steering wheel, the mass supported on the seat surface decreased and there was an additional resonance at 4 Hz. Moving the steering wheel away from the body reduced the apparent mass at the primary resonance frequency and increased the apparent mass around the 4 Hz resonance. As the feet moved forward, the mass supported on the seat surface decreased, indicating that the backrest and footrest supported a greater proportion of the subject weight. Applying force to either the steering wheel or the footrest reduced the apparent mass at resonance and decreased the mass supported on the seat surface. It is concluded that the positions and contact conditions of the hands and the feet affect the biodynamic

Design of a high-mobility multi-terrain robot based on eccentric paddle mechanism.

PubMed

Sun, Yi; Yang, Yang; Ma, Shugen; Pu, Huayan

Gaining high mobility on versatile terrains is a crucial target for designing a mobile robot toward tasks such as search and rescue, scientific exploration, and environment monitoring. Inspired by dextrous limb motion of animals, a novel form of locomotion has been established in our previous study, by proposing an eccentric paddle mechanism (ePaddle) for integrating paddling motion into a traditional wheeled mechanism. In this paper, prototypes of an ePaddle mechanism and an ePaddle-based quadruped robot are presented. Several locomotion modes, including wheeled rolling, legged crawling, legged race-walking, rotational paddling, oscillating paddling, and paddle-aided rolling, are experimentally verified on testbeds with fabricated prototypes. Experimental results confirm that paddle's motion is useful in all the locomotion modes.

Mobile robot trajectory tracking using noisy RSS measurements: an RFID approach.

PubMed

Miah, M Suruz; Gueaieb, Wail

2014-03-01

Most RF beacons-based mobile robot navigation techniques rely on approximating line-of-sight (LOS) distances between the beacons and the robot. This is mostly performed using the robot's received signal strength (RSS) measurements from the beacons. However, accurate mapping between the RSS measurements and the LOS distance is almost impossible to achieve in reverberant environments. This paper presents a partially-observed feedback controller for a wheeled mobile robot where the feedback signal is in the form of noisy RSS measurements emitted from radio frequency identification (RFID) tags. The proposed controller requires neither an accurate mapping between the LOS distance and the RSS measurements, nor the linearization of the robot model. The controller performance is demonstrated through numerical simulations and real-time experiments. ©2013 Published by ISA. All rights reserved.

Mobility performance analysis of an innovation lunar rover with diameter-variable wheel

NASA Astrophysics Data System (ADS)

Sun, Gang; Gao, Feng; Sun, Peng; Xu, Guoyan

2007-11-01

To achieve excellent mobility performance, a four-wheel, all-wheel drive lunar rover with diameter-variable wheel was presented, the wheel can be contracted and extended by the motor equipped in the wheel hub, accompanied with wheel diameter varying from 200mm to 390mm. The wheel sinkage and drawbar pull force were predicated with terramechanics formulae and lunar regolith mechanic parameters employed, furthermore, the slope traversability was investigated through quasi-static modeling mechanic analysis, also the obstacle resistance and the maximum negotiable obstacle height for different wheel radius were derived from the equations of static equilibrium of the rover. Analysis results show that for the innovation lunar rover presented, it will bring much better slope traveling stability and obstacle climbing capability than rovers with normal wheels, these will improve the rover mobility performance and stabilize the rover's frame, smooth the motion of sensors.

Integrated mobile-robot design

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kortenkamp, D.; Huber, M.; Cohen, C.

1993-08-01

Ten mobile robots entered the AAAI '92 Robot Competition, held at last year's national conference. Carmel, the University of Michigan entry, won. The competition consisted of three stages. The first stage required roaming a 22[times]22-meter arena while avoiding static and dynamic obstacles; the second involved searching for and visiting 10 objects in the same arena. The obstacles were at least 1.5 meters apart, while the objects were spaced roughly evenly throughout the arena. Visiting was defined as moving to within two robot diameters of the object. The last stage was a timed race to visit three of the objects locatedmore » earlier and return home. Since the first stage was primarily a subset of the second-stage requirements, and the third-stage implementation was very similar to that of the second, the authors' focus here on the second stage. Carmel (Computer-Aided Robotics for Maintenance, Emergency, and Life support) is based on a commercially available Cybermotion K2A mobile-robot platform. It has a top speed of approximately 800 millimeters per second and moves on three synchronously driven wheels. For sensing, Carmel, has a ring of 24 Polaroid sonar sensors and a single black-and-white charge-coupled-device camera mounted on a rotating table. Carmel has three processors: one controls the drive motors, one fires the sonar ring, and the third, a 486-based PC clone, executes all the high-level modules. The 486 also has a frame grabber for acquiring images. All computation and power are contained on-board.« less

Dual adaptive dynamic control of mobile robots using neural networks.

PubMed

Bugeja, Marvin K; Fabri, Simon G; Camilleri, Liberato

2009-02-01

This paper proposes two novel dual adaptive neural control schemes for the dynamic control of nonholonomic mobile robots. The two schemes are developed in discrete time, and the robot's nonlinear dynamic functions are assumed to be unknown. Gaussian radial basis function and sigmoidal multilayer perceptron neural networks are used for function approximation. In each scheme, the unknown network parameters are estimated stochastically in real time, and no preliminary offline neural network training is used. In contrast to other adaptive techniques hitherto proposed in the literature on mobile robots, the dual control laws presented in this paper do not rely on the heuristic certainty equivalence property but account for the uncertainty in the estimates. This results in a major improvement in tracking performance, despite the plant uncertainty and unmodeled dynamics. Monte Carlo simulation and statistical hypothesis testing are used to illustrate the effectiveness of the two proposed stochastic controllers as applied to the trajectory-tracking problem of a differentially driven wheeled mobile robot.

The design of mobile robot control system for the aged and the disabled

NASA Astrophysics Data System (ADS)

Qiang, Wang; Lei, Shi; Xiang, Gao; Jin, Zhang

2017-01-01

This paper designs a control system of mobile robot for the aged and the disabled, which consists of two main parts: human-computer interaction and drive control module. The data of the two parts is transferred via universal asynchronous receiver/transmitter. In the former part, the speed and direction information of the mobile robot is obtained by hall joystick. In the latter part, the electronic differential algorithm is developed to implement the robot mobile function by driving two-wheel motors. In order to improve the comfort of the robot when speed or direction is changed, the least squares algorithm is used to optimize the speed characteristic curves of the two motors. Experimental results have verified the effectiveness of the designed system.

Cooperating mobile robots

DOEpatents

Harrington, John J.; Eskridge, Steven E.; Hurtado, John E.; Byrne, Raymond H.

2004-02-03

A miniature mobile robot provides a relatively inexpensive mobile robot. A mobile robot for searching an area provides a way for multiple mobile robots in cooperating teams. A robotic system with a team of mobile robots communicating information among each other provides a way to locate a source in cooperation. A mobile robot with a sensor, a communication system, and a processor, provides a way to execute a strategy for searching an area.

Research on Performance of Wire-controlled Hydraulic Steering System Based on Four-wheel Steering

NASA Astrophysics Data System (ADS)

Tao, P.; Jin, X. H.

2018-05-01

In this paper, the steering stability and control strategy of forklift are put forward. Drive based on yawing moment distribution of rotary torque coordination control method, through analyzing the linear two degree of freedom model of forklift truck, forklift yawing angular velocity and mass center side-slip Angle of expectations, as the control target parameters system, using fuzzy controller output driving forklift steering the yawing moment, to drive rotary torque distribution, make the forklift truck to drive horizontal pendulum angular velocity and side-slip Angle tracking reference model very well. In this paper, the lateral stability control system were designed, the joint simulation in MATLAB/Simulink, the simulation results show that under the different partial load, the control system can effectively to control side forklift lateral stability, enhanced the forklift driving safety, for the side forklift steering stability study provides a theoretical basis.

Modeling of Two-Wheeled Self-Balancing Robot Driven by DC Gearmotors

NASA Astrophysics Data System (ADS)

Frankovský, P.; Dominik, L.; Gmiterko, A.; Virgala, I.; Kurylo, P.; Perminova, O.

2017-08-01

This paper is aimed at modelling a two-wheeled self-balancing robot driven by the geared DC motors. A mathematical model consists of two main parts, the model of robot's mechanical structure and the model of the actuator. Linearized equations of motion are derived and the overall model of the two-wheeled self-balancing robot is represented in state-space realization for the purpose of state feedback controller design.

Conversion and control of an all-terrain vehicle for use as an autonomous mobile robot

NASA Astrophysics Data System (ADS)

Jacob, John S.; Gunderson, Robert W.; Fullmer, R. R.

1998-08-01

A systematic approach to ground vehicle automation is presented, combining low-level controls, trajectory generation and closed-loop path correction in an integrated system. Development of cooperative robotics for precision agriculture at Utah State University required the automation of a full-scale motorized vehicle. The Triton Predator 8- wheeled skid-steering all-terrain vehicle was selected for the project based on its ability to maneuver precisely and the simplicity of controlling the hydrostatic drivetrain. Low-level control was achieved by fitting an actuator on the engine throttle, actuators for the left and right drive controls, encoders on the left and right drive shafts to measure wheel speeds, and a signal pick-off on the alternator for measuring engine speed. Closed loop control maintains a desired engine speed and tracks left and right wheel speeds commands. A trajectory generator produces the wheel speed commands needed to steer the vehicle through a predetermined set of map coordinates. A planar trajectory through the points is computed by fitting a 2D cubic spline over each path segment while enforcing initial and final orientation constraints at segment endpoints. Acceleration and velocity profiles are computed for each trajectory segment, with the velocity over each segment dependent on turning radius. Left and right wheel speed setpoints are obtained by combining velocity and path curvature for each low-level timestep. The path correction algorithm uses GPS position and compass orientation information to adjust the wheel speed setpoints according to the 'crosstrack' and 'downtrack' errors and heading error. Nonlinear models of the engine and the skid-steering vehicle/ground interaction were developed for testing the integrated system in simulation. These test lead to several key design improvements which assisted final implementation on the vehicle.

A Low Cost Mobile Robot Based on Proportional Integral Derivative (PID) Control System and Odometer for Education

NASA Astrophysics Data System (ADS)

Haq, R.; Prayitno, H.; Dzulkiflih; Sucahyo, I.; Rahmawati, E.

2018-03-01

In this article, the development of a low cost mobile robot based on PID controller and odometer for education is presented. PID controller and odometer is applied for controlling mobile robot position. Two-dimensional position vector in cartesian coordinate system have been inserted to robot controller as an initial and final position. Mobile robot has been made based on differential drive and sensor magnetic rotary encoder which measured robot position from a number of wheel rotation. Odometry methode use data from actuator movements for predicting change of position over time. The mobile robot is examined to get final position with three different heading angle 30°, 45° and 60° by applying various value of KP, KD and KI constant.

Flocking of multiple mobile robots based on backstepping.

PubMed

Dong, Wenjie

2011-04-01

This paper considers the flocking of multiple nonholonomic wheeled mobile robots. Distributed controllers are proposed with the aid of backstepping techniques, results from graph theory, and singular perturbation theory. The proposed controllers can make the states of a group of robots converge to a desired geometric pattern whose centroid moves along a desired trajectory under the condition that the desired trajectory is available to a portion of the group of robots. Since communication delay is inevitable in distributed control, its effect on the performance of the closed-loop systems is analyzed. It is shown that the proposed controllers work well if communication delays are constant. To show effectiveness of the proposed controllers, simulation results are included.

Distributed Finite-Time Cooperative Control of Multiple High-Order Nonholonomic Mobile Robots.

PubMed

Du, Haibo; Wen, Guanghui; Cheng, Yingying; He, Yigang; Jia, Ruting

2017-12-01

The consensus problem of multiple nonholonomic mobile robots in the form of high-order chained structure is considered in this paper. Based on the model features and the finite-time control technique, a finite-time cooperative controller is explicitly constructed which guarantees that the states consensus is achieved in a finite time. As an application of the proposed results, finite-time formation control of multiple wheeled mobile robots is studied and a finite-time formation control algorithm is proposed. To show effectiveness of the proposed approach, a simulation example is given.

Leg pairs as virtual wheels

NASA Astrophysics Data System (ADS)

Howe, Russel; Duttweiler, Mark; Khanlian, Luke; Setrakian, Mark

2005-05-01

We propose the use of virtual wheels as the starting point of a new vehicle design. Each virtual wheel incorporates a pair of simple legs that, by simulating the rotary motion and ground contact of a traditional wheel, combine many of the benefits of legged and wheeled motion. We describe the use of virtual wheels in the design of a robotic mule, presenting an analysis of the mule's mobility the results of our efforts to model and build such a device.

Assistive devices alter gait patterns in Parkinson disease: advantages of the four-wheeled walker.

PubMed

Kegelmeyer, Deb A; Parthasarathy, Sowmya; Kostyk, Sandra K; White, Susan E; Kloos, Anne D

2013-05-01

Gait abnormalities are a hallmark of Parkinson's disease (PD) and contribute to fall risk. Therapy and exercise are often encouraged to increase mobility and decrease falls. As disease symptoms progress, assistive devices are often prescribed. There are no guidelines for choosing appropriate ambulatory devices. This unique study systematically examined the impact of a broad range of assistive devices on gait measures during walking in both a straight path and around obstacles in individuals with PD. Quantitative gait measures, including velocity, stride length, percent swing and double support time, and coefficients of variation were assessed in 27 individuals with PD with or without one of six different devices including canes, standard and wheeled walkers (two, four or U-Step). Data were collected using the GAITRite and on a figure-of-eight course. All devices, with the exception of four-wheeled and U-Step walkers significantly decreased gait velocity. The four-wheeled walker resulted in less variability in gait measures and had less impact on spontaneous unassisted gait patterns. The U-Step walker exhibited the highest variability across all parameters followed by the two-wheeled and standard walkers. Higher variability has been correlated with increased falls. Though subjects performed better on a figure-of-eight course using either the four-wheeled or the U-Step walker, the four-wheeled walker resulted in the most consistent improvement in overall gait variables. Laser light use on a U-Step walker did not improve gait measures or safety in figure-of-eight compared to other devices. Of the devices tested, the four-wheeled-walker offered the most consistent advantages for improving mobility and safety. Copyright © 2012 Elsevier B.V. All rights reserved.

Four-wheel dual braking for automobiles

NASA Technical Reports Server (NTRS)

Edwards, H. B.

1981-01-01

Each master cylinder applies braking power to all four wheels unlike conventional systems where cylinder operates only two wheels. If one master system fails because of fluid loss, other stops car by braking all four wheels although at half force.

Resolved motion rate and resolved acceleration servo-control of wheeled mobile robots

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muir, P.F.; Neuman, C.P.; Carnegie-Mellon Univ., Pittsburgh, PA

1989-01-01

Accurate motion control of wheeled mobile robots (WMRs) is required for their application to autonomous, semi-autonomous and teleoperated tasks. The similarities between WMRs and stationary manipulators suggest that current, successful, model-based manipulator control algorithms may be applied to WMRs. Special characteristics of WMRs including higher-pairs, closed-chains, friction and unactuated and unsensed joints require innovative modeling methodologies. The WMR modeling challenge has been recently overcome, thus enabling the application of manipulator control algorithms to WMRs. This realization lays the foundation for significant technology transfer from manipulator control to WMR control. We apply two Cartesian-space manipulator control algorithms: resolved motion rate (kinematics-based)more » and resolved acceleration (dynamics-based) control to WMR servo-control. We evaluate simulation studies of two exemplary WMRs: Uranus (a three degree-of-freedom WMR constructed at Carnegie Mellon University), and Bicsun-Bicas (a two degree-of-freedom WMR being constructed at Sandia National Laboratories) under the control of these algorithms. Although resolved motion rate servo-control is adequate for the control of Uranus, resolved acceleration servo-control is required for the control of the mechanically simpler Bicsun-Bicas because it exhibits more dynamic coupling and nonlinearities. Successful accurate motion control of these WMRs in simulation is driving current experimental research studies. 18 refs., 7 figs., 5 tabs.« less

Sensor Fusion Based Model for Collision Free Mobile Robot Navigation.

PubMed

Almasri, Marwah; Elleithy, Khaled; Alajlan, Abrar

2015-12-26

Autonomous mobile robots have become a very popular and interesting topic in the last decade. Each of them are equipped with various types of sensors such as GPS, camera, infrared and ultrasonic sensors. These sensors are used to observe the surrounding environment. However, these sensors sometimes fail and have inaccurate readings. Therefore, the integration of sensor fusion will help to solve this dilemma and enhance the overall performance. This paper presents a collision free mobile robot navigation based on the fuzzy logic fusion model. Eight distance sensors and a range finder camera are used for the collision avoidance approach where three ground sensors are used for the line or path following approach. The fuzzy system is composed of nine inputs which are the eight distance sensors and the camera, two outputs which are the left and right velocities of the mobile robot's wheels, and 24 fuzzy rules for the robot's movement. Webots Pro simulator is used for modeling the environment and the robot. The proposed methodology, which includes the collision avoidance based on fuzzy logic fusion model and line following robot, has been implemented and tested through simulation and real time experiments. Various scenarios have been presented with static and dynamic obstacles using one robot and two robots while avoiding obstacles in different shapes and sizes.

Online Detection of Driver Fatigue Using Steering Wheel Angles for Real Driving Conditions

PubMed Central

Li, Zuojin; Li, Shengbo Eben; Li, Renjie; Cheng, Bo; Shi, Jinliang

2017-01-01

This paper presents a drowsiness on-line detection system for monitoring driver fatigue level under real driving conditions, based on the data of steering wheel angles (SWA) collected from sensors mounted on the steering lever. The proposed system firstly extracts approximate entropy (ApEn) features from fixed sliding windows on real-time steering wheel angles time series. After that, this system linearizes the ApEn features series through an adaptive piecewise linear fitting using a given deviation. Then, the detection system calculates the warping distance between the linear features series of the sample data. Finally, this system uses the warping distance to determine the drowsiness state of the driver according to a designed binary decision classifier. The experimental data were collected from 14.68 h driving under real road conditions, including two fatigue levels: “wake” and “drowsy”. The results show that the proposed system is capable of working online with an average 78.01% accuracy, 29.35% false detections of the “awake” state, and 15.15% false detections of the “drowsy” state. The results also confirm that the proposed method based on SWA signal is valuable for applications in preventing traffic accidents caused by driver fatigue. PMID:28257094

Biomechanical effects of mobile computer location in a vehicle cab.

PubMed

Saginus, Kyle A; Marklin, Richard W; Seeley, Patricia; Simoneau, Guy G; Freier, Stephen

2011-10-01

The objective of this research is to determine the best location to place a conventional mobile computer supported by a commercially available mount in a light truck cab. U.S. and Canadian electric utility companies are in the process of integrating mobile computers into their fleet vehicle cabs. There are no publications on the effect of mobile computer location in a vehicle cab on biomechanical loading, performance, and subjective assessment. The authors tested four locations of mobile computers in a light truck cab in a laboratory study to determine how location affected muscle activity of the lower back and shoulders; joint angles of the shoulders, elbows, and wrist; user performance; and subjective assessment. A total of 22 participants were tested in this study. Placing the mobile computer closer to the steering wheel reduced low back and shoulder muscle activity. Joint angles of the shoulders, elbows, and wrists were also closer to neutral angle. Biomechanical modeling revealed substantially less spinal compression and trunk muscle force. In general, there were no practical differences in performance between the locations. Subjective assessment indicated that users preferred the mobile computer to be as close as possible to the steering wheel. Locating the mobile computer close to the steering wheel reduces risk of injuries, such as low back pain and shoulder tendonitis. Results from the study can guide electric utility companies in the installation of mobile computers into vehicle cabs. Results may also be generalized to other industries that use trucklike vehicles, such as construction.

Event-Based Control Strategy for Mobile Robots in Wireless Environments.

PubMed

Socas, Rafael; Dormido, Sebastián; Dormido, Raquel; Fabregas, Ernesto

2015-12-02

In this paper, a new event-based control strategy for mobile robots is presented. It has been designed to work in wireless environments where a centralized controller has to interchange information with the robots over an RF (radio frequency) interface. The event-based architectures have been developed for differential wheeled robots, although they can be applied to other kinds of robots in a simple way. The solution has been checked over classical navigation algorithms, like wall following and obstacle avoidance, using scenarios with a unique or multiple robots. A comparison between the proposed architectures and the classical discrete-time strategy is also carried out. The experimental results shows that the proposed solution has a higher efficiency in communication resource usage than the classical discrete-time strategy with the same accuracy.

Event-Based Control Strategy for Mobile Robots in Wireless Environments

PubMed Central

Socas, Rafael; Dormido, Sebastián; Dormido, Raquel; Fabregas, Ernesto

2015-01-01

In this paper, a new event-based control strategy for mobile robots is presented. It has been designed to work in wireless environments where a centralized controller has to interchange information with the robots over an RF (radio frequency) interface. The event-based architectures have been developed for differential wheeled robots, although they can be applied to other kinds of robots in a simple way. The solution has been checked over classical navigation algorithms, like wall following and obstacle avoidance, using scenarios with a unique or multiple robots. A comparison between the proposed architectures and the classical discrete-time strategy is also carried out. The experimental results shows that the proposed solution has a higher efficiency in communication resource usage than the classical discrete-time strategy with the same accuracy. PMID:26633412

Semi-autonomous exploration of multi-floor buildings with a legged robot

NASA Astrophysics Data System (ADS)

Wenger, Garrett J.; Johnson, Aaron M.; Taylor, Camillo J.; Koditschek, Daniel E.

2015-05-01

This paper presents preliminary results of a semi-autonomous building exploration behavior using the hexapedal robot RHex. Stairwells are used in virtually all multi-floor buildings, and so in order for a mobile robot to effectively explore, map, clear, monitor, or patrol such buildings it must be able to ascend and descend stairwells. However most conventional mobile robots based on a wheeled platform are unable to traverse stairwells, motivating use of the more mobile legged machine. This semi-autonomous behavior uses a human driver to provide steering input to the robot, as would be the case in, e.g., a tele-operated building exploration mission. The gait selection and transitions between the walking and stair climbing gaits are entirely autonomous. This implementation uses an RGBD camera for stair acquisition, which offers several advantages over a previously documented detector based on a laser range finder, including significantly reduced acquisition time. The sensor package used here also allows for considerable expansion of this behavior. For example, complete automation of the building exploration task driven by a mapping algorithm and higher level planner is presently under development.

Evaluation method on steering for the shape-shifting robot in different configurations

NASA Astrophysics Data System (ADS)

Chang, Jian; Li, Bin; Wang, Chong; Zheng, Huaibing; Li, Zhiqiang

2016-01-01

The evaluation method on steering is based on qualitative manner in existence, which causes the result inaccurate and fuzziness. It reduces the efficiency of process execution. So the method by quantitative manner for the shape-shifting robot in different configurations is proposed. Comparing to traditional evaluation method, the most important aspects which can influence the steering abilities of the robot in different configurations are researched in detail, including the energy, angular velocity, time and space. In order to improve the robustness of system, the ideal and slippage conditions are all considered by mathematical model. Comparing to the traditional weighting confirming method, the extent of robot steering method is proposed by the combination of subjective and objective weighting method. The subjective weighting method can show more preferences of the experts and is based on five-grade scale. The objective weighting method is based on information entropy to determine the factors. By the sensors fixed on the robot, the contract force between track grouser and ground, the intrinsic motion characteristics of robot are obtained and the experiment is done to prove the algorithm which is proposed as the robot in different common configurations. Through the method proposed in the article, fuzziness and inaccurate of the evaluation method has been solved, so the operators can choose the most suitable configuration of the robot to fulfil the different tasks more quickly and simply.

A Concept of the Differentially Driven Three Wheeled Robot

NASA Astrophysics Data System (ADS)

Kelemen, M.; Colville, D. J.; Kelemenová, T.; Virgala, I.; Miková, L.

2013-08-01

The paper deals with the concept of a differentially driven three wheeled robot. The main task for the robot is to follow the navigation black line on white ground. The robot also contains anti-collision sensors for avoiding obstacles on track. Students learn how to deal with signals from sensors and how to control DC motors. Students work with the controller and develop the locomotion algorithm and can attend a competition

Sensor Fusion Based Model for Collision Free Mobile Robot Navigation

PubMed Central

Almasri, Marwah; Elleithy, Khaled; Alajlan, Abrar

2015-01-01

Autonomous mobile robots have become a very popular and interesting topic in the last decade. Each of them are equipped with various types of sensors such as GPS, camera, infrared and ultrasonic sensors. These sensors are used to observe the surrounding environment. However, these sensors sometimes fail and have inaccurate readings. Therefore, the integration of sensor fusion will help to solve this dilemma and enhance the overall performance. This paper presents a collision free mobile robot navigation based on the fuzzy logic fusion model. Eight distance sensors and a range finder camera are used for the collision avoidance approach where three ground sensors are used for the line or path following approach. The fuzzy system is composed of nine inputs which are the eight distance sensors and the camera, two outputs which are the left and right velocities of the mobile robot’s wheels, and 24 fuzzy rules for the robot’s movement. Webots Pro simulator is used for modeling the environment and the robot. The proposed methodology, which includes the collision avoidance based on fuzzy logic fusion model and line following robot, has been implemented and tested through simulation and real time experiments. Various scenarios have been presented with static and dynamic obstacles using one robot and two robots while avoiding obstacles in different shapes and sizes. PMID:26712766

49 CFR 570.60 - Steering system.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 6 2014-10-01 2014-10-01 false Steering system. 570.60 Section 570.60... 10,000 Pounds § 570.60 Steering system. (a) System play. Lash or free play in the steering system... excessive lash or free play in the steering system. Table 2. Steering Wheel Free Play Values Steering wheel...

49 CFR 570.60 - Steering system.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 6 2012-10-01 2012-10-01 false Steering system. 570.60 Section 570.60... 10,000 Pounds § 570.60 Steering system. (a) System play. Lash or free play in the steering system... excessive lash or free play in the steering system. Table 2. Steering Wheel Free Play Values Steering wheel...

49 CFR 570.60 - Steering system.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 6 2011-10-01 2011-10-01 false Steering system. 570.60 Section 570.60... 10,000 Pounds § 570.60 Steering system. (a) System play. Lash or free play in the steering system... excessive lash or free play in the steering system. Table 2. Steering Wheel Free Play Values Steering wheel...

49 CFR 570.60 - Steering system.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 6 2010-10-01 2010-10-01 false Steering system. 570.60 Section 570.60... 10,000 Pounds § 570.60 Steering system. (a) System play. Lash or free play in the steering system... excessive lash or free play in the steering system. Table 2. Steering Wheel Free Play Values Steering wheel...

Development and Control of Multi-Degree-of-Freedom Mobile Robot for Acquisition of Road Environmental Modes

NASA Astrophysics Data System (ADS)

Murata, Naoya; Katsura, Seiichiro

Acquisition of information about the environment around a mobile robot is important for purposes such as controlling the robot from a remote location and in situations such as that when the robot is running autonomously. In many researches, audiovisual information is used. However, acquisition of information about force sensation, which is included in environmental information, has not been well researched. The mobile-hapto, which is a remote control system with force information, has been proposed, but the robot used for the system can acquire only the horizontal component of forces. For this reason, in this research, a three-wheeled mobile robot that consists of seven actuators was developed and its control system was constructed. It can get information on horizontal and vertical forces without using force sensors. By using this robot, detailed information on the forces in the environment can be acquired and the operability of the robot and its capability to adjust to the environment are expected to improve.

How do walkers avoid a mobile robot crossing their way?

PubMed

Vassallo, Christian; Olivier, Anne-Hélène; Souères, Philippe; Crétual, Armel; Stasse, Olivier; Pettré, Julien

2017-01-01

Robots and Humans have to share the same environment more and more often. In the aim of steering robots in a safe and convenient manner among humans it is required to understand how humans interact with them. This work focuses on collision avoidance between a human and a robot during locomotion. Having in mind previous results on human obstacle avoidance, as well as the description of the main principles which guide collision avoidance strategies, we observe how humans adapt a goal-directed locomotion task when they have to interfere with a mobile robot. Our results show differences in the strategy set by humans to avoid a robot in comparison with avoiding another human. Humans prefer to give the way to the robot even when they are likely to pass first at the beginning of the interaction. Copyright © 2016 Elsevier B.V. All rights reserved.

Design, Implementation and Validation of the Three-Wheel Holonomic Motion System of the Assistant Personal Robot (APR).

PubMed

Moreno, Javier; Clotet, Eduard; Lupiañez, Ruben; Tresanchez, Marcel; Martínez, Dani; Pallejà, Tomàs; Casanovas, Jordi; Palacín, Jordi

2016-10-10

This paper presents the design, implementation and validation of the three-wheel holonomic motion system of a mobile robot designed to operate in homes. The holonomic motion system is described in terms of mechanical design and electronic control. The paper analyzes the kinematics of the motion system and validates the estimation of the trajectory comparing the displacement estimated with the internal odometry of the motors and the displacement estimated with a SLAM procedure based on LIDAR information. Results obtained in different experiments have shown a difference on less than 30 mm between the position estimated with the SLAM and odometry, and a difference in the angular orientation of the mobile robot lower than 5° in absolute displacements up to 1000 mm.

Design, Implementation and Validation of the Three-Wheel Holonomic Motion System of the Assistant Personal Robot (APR)

PubMed Central

Moreno, Javier; Clotet, Eduard; Lupiañez, Ruben; Tresanchez, Marcel; Martínez, Dani; Pallejà, Tomàs; Casanovas, Jordi; Palacín, Jordi

2016-01-01

This paper presents the design, implementation and validation of the three-wheel holonomic motion system of a mobile robot designed to operate in homes. The holonomic motion system is described in terms of mechanical design and electronic control. The paper analyzes the kinematics of the motion system and validates the estimation of the trajectory comparing the displacement estimated with the internal odometry of the motors and the displacement estimated with a SLAM procedure based on LIDAR information. Results obtained in different experiments have shown a difference on less than 30 mm between the position estimated with the SLAM and odometry, and a difference in the angular orientation of the mobile robot lower than 5° in absolute displacements up to 1000 mm. PMID:27735857

Mobile Robots for Localizing Gas Emission Sources on Landfill Sites: Is Bio-Inspiration the Way to Go?

PubMed Central

Hernandez Bennetts, Victor; Lilienthal, Achim J.; Neumann, Patrick P.; Trincavelli, Marco

2011-01-01

Roboticists often take inspiration from animals for designing sensors, actuators, or algorithms that control the behavior of robots. Bio-inspiration is motivated with the uncanny ability of animals to solve complex tasks like recognizing and manipulating objects, walking on uneven terrains, or navigating to the source of an odor plume. In particular the task of tracking an odor plume up to its source has nearly exclusively been addressed using biologically inspired algorithms and robots have been developed, for example, to mimic the behavior of moths, dung beetles, or lobsters. In this paper we argue that biomimetic approaches to gas source localization are of limited use, primarily because animals differ fundamentally in their sensing and actuation capabilities from state-of-the-art gas-sensitive mobile robots. To support our claim, we compare actuation and chemical sensing available to mobile robots to the corresponding capabilities of moths. We further characterize airflow and chemosensor measurements obtained with three different robot platforms (two wheeled robots and one flying micro-drone) in four prototypical environments and show that the assumption of a constant and unidirectional airflow, which is the basis of many gas source localization approaches, is usually far from being valid. This analysis should help to identify how underlying principles, which govern the gas source tracking behavior of animals, can be usefully “translated” into gas source localization approaches that fully take into account the capabilities of mobile robots. We also describe the requirements for a reference application, monitoring of gas emissions at landfill sites with mobile robots, and discuss an engineered gas source localization approach based on statistics as an alternative to biologically inspired algorithms. PMID:22319493

Mobile robots for localizing gas emission sources on landfill sites: is bio-inspiration the way to go?

PubMed

Hernandez Bennetts, Victor; Lilienthal, Achim J; Neumann, Patrick P; Trincavelli, Marco

2011-01-01

Roboticists often take inspiration from animals for designing sensors, actuators, or algorithms that control the behavior of robots. Bio-inspiration is motivated with the uncanny ability of animals to solve complex tasks like recognizing and manipulating objects, walking on uneven terrains, or navigating to the source of an odor plume. In particular the task of tracking an odor plume up to its source has nearly exclusively been addressed using biologically inspired algorithms and robots have been developed, for example, to mimic the behavior of moths, dung beetles, or lobsters. In this paper we argue that biomimetic approaches to gas source localization are of limited use, primarily because animals differ fundamentally in their sensing and actuation capabilities from state-of-the-art gas-sensitive mobile robots. To support our claim, we compare actuation and chemical sensing available to mobile robots to the corresponding capabilities of moths. We further characterize airflow and chemosensor measurements obtained with three different robot platforms (two wheeled robots and one flying micro-drone) in four prototypical environments and show that the assumption of a constant and unidirectional airflow, which is the basis of many gas source localization approaches, is usually far from being valid. This analysis should help to identify how underlying principles, which govern the gas source tracking behavior of animals, can be usefully "translated" into gas source localization approaches that fully take into account the capabilities of mobile robots. We also describe the requirements for a reference application, monitoring of gas emissions at landfill sites with mobile robots, and discuss an engineered gas source localization approach based on statistics as an alternative to biologically inspired algorithms.

Automatic guidance control of an articulated all-wheel-steered vehicle

NASA Astrophysics Data System (ADS)

Kim, Young Chol; Yun, Kyong-Han; Min, Kyung-Deuk

2014-04-01

This paper presents automatic guidance control of a single-articulated all-wheel-steered vehicle being developed by the Korea Railroad Research Institute. The vehicle has an independent drive motor on each wheel except for the front axle. The guidance controller is designed so that the vehicle follows the given reference path within permissible lateral deviations. We use a three-input/three-output linearised model derived from the nonlinear dynamic model of the vehicle. For the purpose of simplifying the controller and making it tunable, we consider a decentralised control configuration. We first design a second-order decoupling compensator for the two-input/two-output system that is strongly coupled and then design a first-order controller for each decoupled feedback loop by using the characteristic ratio assignment method. The simulation results for the nonlinear dynamic model indicate that the proposed control configuration successfully achieves the design objectives.

Application of neural models as controllers in mobile robot velocity control loop

NASA Astrophysics Data System (ADS)

Cerkala, Jakub; Jadlovska, Anna

2017-01-01

This paper presents the application of an inverse neural models used as controllers in comparison to classical PI controllers for velocity tracking control task used in two-wheel, differentially driven mobile robot. The PI controller synthesis is based on linear approximation of actuators with equivalent load. In order to obtain relevant datasets for training of feed-forward multi-layer perceptron based neural network used as neural model, the mathematical model of mobile robot, that combines its kinematic and dynamic properties such as chassis dimensions, center of gravity offset, friction and actuator parameters is used. Neural models are trained off-line to act as an inverse dynamics of DC motors with particular load using data collected in simulation experiment for motor input voltage step changes within bounded operating area. The performances of PI controllers versus inverse neural models in mobile robot internal velocity control loops are demonstrated and compared in simulation experiment of navigation control task for line segment motion in plane.

Adding navigation, artificial audition and vital sign monitoring capabilities to a telepresence mobile robot for remote home care applications.

PubMed

Laniel, Sebastien; Letourneau, Dominic; Labbe, Mathieu; Grondin, Francois; Polgar, Janice; Michaud, Francois

2017-07-01

A telepresence mobile robot is a remote-controlled, wheeled device with wireless internet connectivity for bidirectional audio, video and data transmission. In health care, a telepresence robot could be used to have a clinician or a caregiver assist seniors in their homes without having to travel to these locations. Many mobile telepresence robotic platforms have recently been introduced on the market, bringing mobility to telecommunication and vital sign monitoring at reasonable costs. What is missing for making them effective remote telepresence systems for home care assistance are capabilities specifically needed to assist the remote operator in controlling the robot and perceiving the environment through the robot's sensors or, in other words, minimizing cognitive load and maximizing situation awareness. This paper describes our approach adding navigation, artificial audition and vital sign monitoring capabilities to a commercially available telepresence mobile robot. This requires the use of a robot control architecture to integrate the autonomous and teleoperation capabilities of the platform.

Development of the auto-steering software and equipment technology (ASSET)

NASA Astrophysics Data System (ADS)

McKay, Mark D.; Anderson, Matthew O.; Wadsworth, Derek C.

2003-09-01

The Idaho National Engineering and Environmental Laboratory (INEEL), through collaboration with INSAT Co., has developed a low cost robotic auto-steering system for parallel contour swathing. The capability to perform parallel contour swathing while minimizing "skip" and "overlap" is a necessity for cost-effective crop management within precision agriculture. Current methods for performing parallel contour swathing consist of using a Differential Global Position System (DGPS) coupled with a light bar system to prompt an operator where to steer. The complexity of operating heavy equipment, ensuring proper chemical mixture and application, and steering to a light bar indicator can be overwhelming to an operator. To simplify these tasks, an inexpensive robotic steering system has been developed and tested on several farming implements. This development leveraged research conducted by the INEEL and Utah State University. The INEEL-INSAT Auto-Steering Software and Equipment Technology provides the following: 1) the ability to drive in a straight line within +/- 2 feet while traveling at least 15 mph, 2) interfaces to a Real Time Kinematic (RTK) DGPS and sub-meter DGPS, 3) safety features such as Emergency-stop, steering wheel deactivation, computer watchdog deactivation, etc., and 4) a low-cost, field-ready system that is easily adapted to other systems.

Dynamics and control for Constrained Multibody Systems modeled with Maggi's equation: Application to Differential Mobile Robots Partll

NASA Astrophysics Data System (ADS)

Amengonu, Yawo H.; Kakad, Yogendra P.

2014-07-01

Quasivelocity techniques were applied to derive the dynamics of a Differential Wheeled Mobile Robot (DWMR) in the companion paper. The present paper formulates a control system design for trajectory tracking of this class of robots. The method develops a feedback linearization technique for the nonlinear system using dynamic extension algorithm. The effectiveness of the nonlinear controller is illustrated with simulation example.

Development of a mobile robot for the 1995 AUVS competition

NASA Astrophysics Data System (ADS)

Matthews, Bradley O.; Ruthemeyer, Michael A.; Perdue, David; Hall, Ernest L.

1995-12-01

Automated guided vehicles (AGVs) have many potential applications in manufacturing, medicine, space and defense. The purpose of this paper is to describe exploratory research on the design of a modular autonomous mobile robot controller. The advantages of a modular system are related to portability and the fact that any vehicle can become autonomous with minimal modifications. A mobile robot test-bed has been constructed using a golf cart base. This cart has full speed control with guidance provided by a vision system and obstacle avoidance using ultrasonic sensors systems. The speed and steering control are supervised by a 486 computer through a 3-axis motion controller. The obstacle avoidance system is based on a micro-controller interfaced with six ultrasonic transducers. The is micro-controller independently handles all timing and distance calculations and sends a steering angle correction back to the computer via the serial line. This design yields a portable independent system, where even computer communication is not necessary. Vision guidance is accomplished with a CCD camera with a zoom lens. The data is collected through a commercial tracking device, communicating with the computer the X,Y coordinates of the lane marker. Testing of these systems yielded positive results by showing that at five mph the vehicle can follow a line and at the same time avoid obstacles. This design, in its modularity, creates a portable autonomous controller applicable for any mobile vehicle with only minor adaptations.

A satellite orbital testbed for SATCOM using mobile robots

NASA Astrophysics Data System (ADS)

Shen, Dan; Lu, Wenjie; Wang, Zhonghai; Jia, Bin; Wang, Gang; Wang, Tao; Chen, Genshe; Blasch, Erik; Pham, Khanh

2016-05-01

This paper develops and evaluates a satellite orbital testbed (SOT) for satellite communications (SATCOM). SOT can emulate the 3D satellite orbit using the omni-wheeled robots and a robotic arm. The 3D motion of satellite is partitioned into the movements in the equatorial plane and the up-down motions in the vertical plane. The former actions are emulated by omni-wheeled robots while the up-down motions are performed by a stepped-motor-controlled-ball along a rod (robotic arm), which is attached to the robot. The emulated satellite positions will go to the measure model, whose results will be used to perform multiple space object tracking. Then the tracking results will go to the maneuver detection and collision alert. The satellite maneuver commands will be translated to robots commands and robotic arm commands. In SATCOM, the effects of jamming depend on the range and angles of the positions of satellite transponder relative to the jamming satellite. We extend the SOT to include USRP transceivers. In the extended SOT, the relative ranges and angles are implemented using omni-wheeled robots and robotic arms.

Design and implementation of self-balancing coaxial two wheel robot based on HSIC

NASA Astrophysics Data System (ADS)

Hu, Tianlian; Zhang, Hua; Dai, Xin; Xia, Xianfeng; Liu, Ran; Qiu, Bo

2007-12-01

This thesis has studied the control problem concerning position and orientation control of self-balancing coaxial two wheel robot based on the human simulated intelligent control (HSIC) theory. Adopting Lagrange equation, the dynamic model of self-balancing coaxial two-wheel Robot is built up, and the Sensory-motor Intelligent Schemas (SMIS) of HSIC controller for the robot is designed by analyzing its movement and simulating the human controller. In robot's motion process, by perceiving position and orientation of the robot and using multi-mode control strategy based on characteristic identification, the HSIC controller enables the robot to control posture. Utilizing Matlab/Simulink, a simulation platform is established and a motion controller is designed and realized based on RT-Linux real-time operating system, employing high speed ARM9 processor S3C2440 as kernel of the motion controller. The effectiveness of the new design is testified by the experiment.

Anthropometry and Standards for Wheeled Mobility: An International Comparison

ERIC Educational Resources Information Center

Steinfeld, Edward; Maisel, Jordana; Feathers, David; D'Souza, Clive

2010-01-01

Space requirements for accommodating wheeled mobility devices and their users in the built environment are key components of standards for accessible design. These requirements typically include dimensions for clear floor areas, maneuvering clearances, seat and knee clearance heights, as well as some reference dimensions on wheeled mobility device…

Volunteers Oriented Interface Design for the Remote Navigation of Rescue Robots at Large-Scale Disaster Sites

NASA Astrophysics Data System (ADS)

Yang, Zhixiao; Ito, Kazuyuki; Saijo, Kazuhiko; Hirotsune, Kazuyuki; Gofuku, Akio; Matsuno, Fumitoshi

This paper aims at constructing an efficient interface being similar to those widely used in human daily life, to fulfill the need of many volunteer rescuers operating rescue robots at large-scale disaster sites. The developed system includes a force feedback steering wheel interface and an artificial neural network (ANN) based mouse-screen interface. The former consists of a force feedback steering control and a six monitors’ wall. It provides a manual operation like driving cars to navigate a rescue robot. The latter consists of a mouse and a camera’s view displayed in a monitor. It provides a semi-autonomous operation by mouse clicking to navigate a rescue robot. Results of experiments show that a novice volunteer can skillfully navigate a tank rescue robot through both interfaces after 20 to 30 minutes of learning their operation respectively. The steering wheel interface has high navigating speed in open areas, without restriction of terrains and surface conditions of a disaster site. The mouse-screen interface is good at exact navigation in complex structures, while bringing little tension to operators. The two interfaces are designed to switch into each other at any time to provide a combined efficient navigation method.

Driving a Semiautonomous Mobile Robotic Car Controlled by an SSVEP-Based BCI.

PubMed

Stawicki, Piotr; Gembler, Felix; Volosyak, Ivan

2016-01-01

Brain-computer interfaces represent a range of acknowledged technologies that translate brain activity into computer commands. The aim of our research is to develop and evaluate a BCI control application for certain assistive technologies that can be used for remote telepresence or remote driving. The communication channel to the target device is based on the steady-state visual evoked potentials. In order to test the control application, a mobile robotic car (MRC) was introduced and a four-class BCI graphical user interface (with live video feedback and stimulation boxes on the same screen) for piloting the MRC was designed. For the purpose of evaluating a potential real-life scenario for such assistive technology, we present a study where 61 subjects steered the MRC through a predetermined route. All 61 subjects were able to control the MRC and finish the experiment (mean time 207.08 s, SD 50.25) with a mean (SD) accuracy and ITR of 93.03% (5.73) and 14.07 bits/min (4.44), respectively. The results show that our proposed SSVEP-based BCI control application is suitable for mobile robots with a shared-control approach. We also did not observe any negative influence of the simultaneous live video feedback and SSVEP stimulation on the performance of the BCI system.

Mobility platform coupling device and method for coupling mobility platforms

DOEpatents

Shirey, David L.; Hayward, David R.; Buttz, James H.

2002-01-01

A coupling device for connecting a first mobility platform to a second mobility platform in tandem. An example mobility platform is a robot. The coupling device has a loose link mode for normal steering conditions and a locking position, tight link mode for navigation across difficult terrain and across obstacles, for traversing chasms, and for navigating with a reduced footprint in tight steering conditions.

Development of a two wheeled self balancing robot with speech recognition and navigation algorithm

NASA Astrophysics Data System (ADS)

Rahman, Md. Muhaimin; Ashik-E-Rasul, Haq, Nowab. Md. Aminul; Hassan, Mehedi; Hasib, Irfan Mohammad Al; Hassan, K. M. Rafidh

2016-07-01

This paper is aimed to discuss modeling, construction and development of navigation algorithm of a two wheeled self balancing mobile robot in an enclosure. In this paper, we have discussed the design of two of the main controller algorithms, namely PID algorithms, on the robot model. Simulation is performed in the SIMULINK environment. The controller is developed primarily for self-balancing of the robot and also it's positioning. As for the navigation in an enclosure, template matching algorithm is proposed for precise measurement of the robot position. The navigation system needs to be calibrated before navigation process starts. Almost all of the earlier template matching algorithms that can be found in the open literature can only trace the robot. But the proposed algorithm here can also locate the position of other objects in an enclosure, like furniture, tables etc. This will enable the robot to know the exact location of every stationary object in the enclosure. Moreover, some additional features, such as Speech Recognition and Object Detection, are added. For Object Detection, the single board Computer Raspberry Pi is used. The system is programmed to analyze images captured via the camera, which are then processed through background subtraction, followed by active noise reduction.

Rover Wheel-Actuated Tool Interface

NASA Technical Reports Server (NTRS)

Matthews, Janet; Ahmad, Norman; Wilcox, Brian

2007-01-01

A report describes an interface for utilizing some of the mobility features of a mobile robot for general-purpose manipulation of tools and other objects. The robot in question, now undergoing conceptual development for use on the Moon, is the All-Terrain Hex-Limbed Extra-Terrestrial Explorer (ATHLETE) rover, which is designed to roll over gentle terrain or walk over rough or steep terrain. Each leg of the robot is a six-degree-of-freedom general purpose manipulator tipped by a wheel with a motor drive. The tool interface includes a square cross-section peg, equivalent to a conventional socket-wrench drive, that rotates with the wheel. The tool interface also includes a clamp that holds a tool on the peg, and a pair of fold-out cameras that provides close-up stereoscopic images of the tool and its vicinity. The field of view of the imagers is actuated by the clamp mechanism and is specific to each tool. The motor drive can power any of a variety of tools, including rotating tools for helical fasteners, drills, and such clamping tools as pliers. With the addition of a flexible coupling, it could also power another tool or remote manipulator at a short distance. The socket drive can provide very high torque and power because it is driven by the wheel motor.

Training a Network of Electronic Neurons for Control of a Mobile Robot

NASA Astrophysics Data System (ADS)

Vromen, T. G. M.; Steur, E.; Nijmeijer, H.

An adaptive training procedure is developed for a network of electronic neurons, which controls a mobile robot driving around in an unknown environment while avoiding obstacles. The neuronal network controls the angular velocity of the wheels of the robot based on the sensor readings. The nodes in the neuronal network controller are clusters of neurons rather than single neurons. The adaptive training procedure ensures that the input-output behavior of the clusters is identical, even though the constituting neurons are nonidentical and have, in isolation, nonidentical responses to the same input. In particular, we let the neurons interact via a diffusive coupling, and the proposed training procedure modifies the diffusion interaction weights such that the neurons behave synchronously with a predefined response. The working principle of the training procedure is experimentally validated and results of an experiment with a mobile robot that is completely autonomously driving in an unknown environment with obstacles are presented.

An adaptive actuator failure compensation scheme for two linked 2WD mobile robots

NASA Astrophysics Data System (ADS)

Ma, Yajie; Al-Dujaili, Ayad; Cocquempot, Vincent; El Badaoui El Najjar, Maan

2017-01-01

This paper develops a new adaptive compensation control scheme for two linked mobile robots with actuator failurs. A configuration with two linked two-wheel drive (2WD) mobile robots is proposed, and the modelling of its kinematics and dynamics are given. An adaptive failure compensation scheme is developed to compensate actuator failures, consisting of a kinematic controller and a multi-design integration based dynamic controller. The kinematic controller is a virtual one, and based on which, multiple adaptive dynamic control signals are designed which covers all possible failure cases. By combing these dynamic control signals, the dynamic controller is designed, which ensures system stability and asymptotic tracking properties. Simulation results verify the effectiveness of the proposed adaptive failure compensation scheme.

On-Line Method and Apparatus for Coordinated Mobility and Manipulation of Mobile Robots

NASA Technical Reports Server (NTRS)

Seraji, Homayoun (Inventor)

1996-01-01

A simple and computationally efficient approach is disclosed for on-line coordinated control of mobile robots consisting of a manipulator arm mounted on a mobile base. The effect of base mobility on the end-effector manipulability index is discussed. The base mobility and arm manipulation degrees-of-freedom are treated equally as the joints of a kinematically redundant composite robot. The redundancy introduced by the mobile base is exploited to satisfy a set of user-defined additional tasks during the end-effector motion. A simple on-line control scheme is proposed which allows the user to assign weighting factors to individual degrees-of-mobility and degrees-of-manipulation, as well as to each task specification. The computational efficiency of the control algorithm makes it particularly suitable for real-time implementations. Four case studies are discussed in detail to demonstrate the application of the coordinated control scheme to various mobile robots.

Tandem mobile robot system

DOEpatents

Buttz, James H.; Shirey, David L.; Hayward, David R.

2003-01-01

A robotic vehicle system for terrain navigation mobility provides a way to climb stairs, cross crevices, and navigate across difficult terrain by coupling two or more mobile robots with a coupling device and controlling the robots cooperatively in tandem.

Evolutionary Fuzzy Control and Navigation for Two Wheeled Robots Cooperatively Carrying an Object in Unknown Environments.

PubMed

Juang, Chia-Feng; Lai, Min-Ge; Zeng, Wan-Ting

2015-09-01

This paper presents a method that allows two wheeled, mobile robots to navigate unknown environments while cooperatively carrying an object. In the navigation method, a leader robot and a follower robot cooperatively perform either obstacle boundary following (OBF) or target seeking (TS) to reach a destination. The two robots are controlled by fuzzy controllers (FC) whose rules are learned through an adaptive fusion of continuous ant colony optimization and particle swarm optimization (AF-CACPSO), which avoids the time-consuming task of manually designing the controllers. The AF-CACPSO-based evolutionary fuzzy control approach is first applied to the control of a single robot to perform OBF. The learning approach is then applied to achieve cooperative OBF with two robots, where an auxiliary FC designed with the AF-CACPSO is used to control the follower robot. For cooperative TS, a rule for coordination of the two robots is developed. To navigate cooperatively, a cooperative behavior supervisor is introduced to select between cooperative OBF and cooperative TS. The performance of the AF-CACPSO is verified through comparisons with various population-based optimization algorithms for the OBF learning problem. Simulations and experiments verify the effectiveness of the approach for cooperative navigation of two robots.

16 CFR 1420.3 - Requirements for four-wheel ATVs.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Requirements for four-wheel ATVs. 1420.3... REGULATIONS REQUIREMENTS FOR ALL TERRAIN VEHICLES § 1420.3 Requirements for four-wheel ATVs. (a) Each ATV shall comply with all applicable provisions of the American National Standard for Four Wheel All-Terrain...

Electronic differential control of 2WD electric vehicle considering steering stability

NASA Astrophysics Data System (ADS)

Hua, Yiding; Jiang, Haobin; Geng, Guoqing

2017-03-01

Aiming at the steering wheel differential steering control technology of rear wheel independent driving electric wheel, considering the assisting effect of electronic differential control on vehicle steering, based on the high speed steering characteristic of electric wheel car, the electronic differential speed of auxiliary wheel steering is also studied. A yaw moment control strategy is applied to the vehicle at high speed. Based on the vehicle stability reference value, yaw rate is used to design the fuzzy controller to distribute the driving wheel torque. The simulation results show that the basic electronic differential speed function is realized based on the yaw moment control strategy, while the vehicle stability control is improved and the driving safety is enhanced. On the other hand, the torque control strategy can also assist steering of vehicle.

Driver assistance system for passive multi-trailer vehicles with haptic steering limitations on the leading unit.

PubMed

Morales, Jesús; Mandow, Anthony; Martínez, Jorge L; Reina, Antonio J; García-Cerezo, Alfonso

2013-04-03

Driving vehicles with one or more passive trailers has difficulties in both forward and backward motion due to inter-unit collisions, jackknife, and lack of visibility. Consequently, advanced driver assistance systems (ADAS) for multi-trailer combinations can be beneficial to accident avoidance as well as to driver comfort. The ADAS proposed in this paper aims to prevent unsafe steering commands by means of a haptic handwheel. Furthermore, when driving in reverse, the steering-wheel and pedals can be used as if the vehicle was driven from the back of the last trailer with visual aid from a rear-view camera. This solution, which can be implemented in drive-by-wire vehicles with hitch angle sensors, profits from two methods previously developed by the authors: safe steering by applying a curvature limitation to the leading unit, and a virtual tractor concept for backward motion that includes the complex case of set-point propagation through on-axle hitches. The paper addresses system requirements and provides implementation details to tele-operate two different off- and on-axle combinations of a tracked mobile robot pulling and pushing two dissimilar trailers.

Driver Assistance System for Passive Multi-Trailer Vehicles with Haptic Steering Limitations on the Leading Unit

PubMed Central

Morales, Jesús; Mandow, Anthony; Martínez, Jorge L.; Reina, Antonio J.; García-Cerezo, Alfonso

2013-01-01

Driving vehicles with one or more passive trailers has difficulties in both forward and backward motion due to inter-unit collisions, jackknife, and lack of visibility. Consequently, advanced driver assistance systems (ADAS) for multi-trailer combinations can be beneficial to accident avoidance as well as to driver comfort. The ADAS proposed in this paper aims to prevent unsafe steering commands by means of a haptic handwheel. Furthermore, when driving in reverse, the steering-wheel and pedals can be used as if the vehicle was driven from the back of the last trailer with visual aid from a rear-view camera. This solution, which can be implemented in drive-by-wire vehicles with hitch angle sensors, profits from two methods previously developed by the authors: safe steering by applying a curvature limitation to the leading unit, and a virtual tractor concept for backward motion that includes the complex case of set-point propagation through on-axle hitches. The paper addresses system requirements and provides implementation details to tele-operate two different off- and on-axle combinations of a tracked mobile robot pulling and pushing two dissimilar trailers. PMID:23552102

Driver behavior following an automatic steering intervention.

PubMed

Fricke, Nicola; Griesche, Stefan; Schieben, Anna; Hesse, Tobias; Baumann, Martin

2015-10-01

The study investigated driver behavior toward an automatic steering intervention of a collision mitigation system. Forty participants were tested in a driving simulator and confronted with an inevitable collision. They performed a naïve drive and afterwards a repeated exposure in which they were told to hold the steering wheel loosely. In a third drive they experienced a false alarm situation. Data on driving behavior, i.e. steering and braking behavior as well as subjective data was assessed in the scenarios. Results showed that most participants held on to the steering wheel strongly or counter-steered during the system intervention during the first encounter. Moreover, subjective data collected after the first drive showed that the majority of drivers was not aware of the system intervention. Data from the repeated drive in which participants were instructed to hold the steering wheel loosely, led to significantly more participants holding the steering wheel loosely and thus complying with the instruction. This study seems to imply that without knowledge and information of the system about an upcoming intervention, the most prevalent driving behavior is a strong reaction with the steering wheel similar to an automatic steering reflex which decreases the system's effectiveness. Results of the second drive show some potential for countermeasures, such as informing drivers shortly before a system intervention in order to prevent inhibiting reactions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Static Force-Deflection Properties of Automobile Steering Components

DOT National Transportation Integrated Search

1987-06-01

This report provides the static force-deflection test results for 28 steering columns and 24 steering wheels used in domestic and import passener cars from model year 1975 to 1985. The steering columns and wheels tested include approzimately 90 perce...

A global approach to kinematic path planning to robots with holonomic and nonholonomic constraints

NASA Technical Reports Server (NTRS)

Divelbiss, Adam; Seereeram, Sanjeev; Wen, John T.

1993-01-01

Robots in applications may be subject to holonomic or nonholonomic constraints. Examples of holonomic constraints include a manipulator constrained through the contact with the environment, e.g., inserting a part, turning a crank, etc., and multiple manipulators constrained through a common payload. Examples of nonholonomic constraints include no-slip constraints on mobile robot wheels, local normal rotation constraints for soft finger and rolling contacts in grasping, and conservation of angular momentum of in-orbit space robots. The above examples all involve equality constraints; in applications, there are usually additional inequality constraints such as robot joint limits, self collision and environment collision avoidance constraints, steering angle constraints in mobile robots, etc. The problem of finding a kinematically feasible path that satisfies a given set of holonomic and nonholonomic constraints, of both equality and inequality types is addressed. The path planning problem is first posed as a finite time nonlinear control problem. This problem is subsequently transformed to a static root finding problem in an augmented space which can then be iteratively solved. The algorithm has shown promising results in planning feasible paths for redundant arms satisfying Cartesian path following and goal endpoint specifications, and mobile vehicles with multiple trailers. In contrast to local approaches, this algorithm is less prone to problems such as singularities and local minima.

Power And Propulsion Systems For Mobile Robotic Applications

NASA Astrophysics Data System (ADS)

Layuan, Li; Haiming, Zou

1987-02-01

Choosing the best power and propulsion systems for mobile robotic land vehicle applications requires consideration of technologies. The electric power requirements for onboard electronic and auxiliary equipment include 110/220 volt 60 Hz ac power as well as low voltage dc power. Weight and power are saved by either direct dc power distribution, or high frequency (20 kHz) ac power distribution. Vehicle control functions are performed electronically but steering, braking and traction power may be distributed electrically, mechanically or by fluid (hydraulic) means. Electric drive is practical, even for small vehicles, provided that advanced electric motors are used. Such electric motors have demonstrated power densities of 3.1 kilowatts per kilogram with devices in the 15 kilowatt range. Electric motors have a lower torque, but higher power density as compared to hydraulic or mechanical transmission systems. Power density being comparable, electric drives were selected to best meet the other requirements for robotic vehicles. Two robotic vehicle propulsion system designs are described to illustrate the implementation of electric drive over a vehicle size range of 250-7500 kilograms.

Independent Orbiter Assessment (IOA): Assessment of the nose wheel steering subsystem

NASA Technical Reports Server (NTRS)

Mediavilla, Anthony Scott

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Nose Wheel Steering (NWS) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the proposed NASA post 51-L FMEA/CIL baseline. A resolution of each discrepancy from the comparison is provided through additional analysis as required. This report documents the results of that comparison for the Orbiter NWS hardware.

Driving a Semiautonomous Mobile Robotic Car Controlled by an SSVEP-Based BCI

PubMed Central

2016-01-01

Brain-computer interfaces represent a range of acknowledged technologies that translate brain activity into computer commands. The aim of our research is to develop and evaluate a BCI control application for certain assistive technologies that can be used for remote telepresence or remote driving. The communication channel to the target device is based on the steady-state visual evoked potentials. In order to test the control application, a mobile robotic car (MRC) was introduced and a four-class BCI graphical user interface (with live video feedback and stimulation boxes on the same screen) for piloting the MRC was designed. For the purpose of evaluating a potential real-life scenario for such assistive technology, we present a study where 61 subjects steered the MRC through a predetermined route. All 61 subjects were able to control the MRC and finish the experiment (mean time 207.08 s, SD 50.25) with a mean (SD) accuracy and ITR of 93.03% (5.73) and 14.07 bits/min (4.44), respectively. The results show that our proposed SSVEP-based BCI control application is suitable for mobile robots with a shared-control approach. We also did not observe any negative influence of the simultaneous live video feedback and SSVEP stimulation on the performance of the BCI system. PMID:27528864

Improved LTVMPC design for steering control of autonomous vehicle

NASA Astrophysics Data System (ADS)

Velhal, Shridhar; Thomas, Susy

2017-01-01

An improved linear time varying model predictive control for steering control of autonomous vehicle running on slippery road is presented. Control strategy is designed such that the vehicle will follow the predefined trajectory with highest possible entry speed. In linear time varying model predictive control, nonlinear vehicle model is successively linearized at each sampling instant. This linear time varying model is used to design MPC which will predict the future horizon. By incorporating predicted input horizon in each successive linearization the effectiveness of controller has been improved. The tracking performance using steering with front wheel and braking at four wheels are presented to illustrate the effectiveness of the proposed method.

Control of an automated mobile manipulator using artificial immune system

NASA Astrophysics Data System (ADS)

Deepak, B. B. V. L.; Parhi, Dayal R.

2016-03-01

This paper addresses the coordination and control of a wheeled mobile manipulator (WMM) using artificial immune system. The aim of the developed methodology is to navigate the system autonomously and transport jobs and tools in manufacturing environments. This study integrates the kinematic structures of a four-axis manipulator and a differential wheeled mobile platform. The motion of the developed WMM is controlled by the complete system of parametric equation in terms of joint velocities and makes the robot to follow desired trajectories by the manipulator and platform within its workspace. The developed robot system performs its action intelligently according to the sensed environmental criteria within its search space. To verify the effectiveness of the proposed immune-based motion planner for WMM, simulations as well as experimental results are presented in various unknown environments.

Online absolute pose compensation and steering control of industrial robot based on six degrees of freedom laser measurement

NASA Astrophysics Data System (ADS)

Yang, Juqing; Wang, Dayong; Fan, Baixing; Dong, Dengfeng; Zhou, Weihu

2017-03-01

In-situ intelligent manufacturing for large-volume equipment requires industrial robots with absolute high-accuracy positioning and orientation steering control. Conventional robots mainly employ an offline calibration technology to identify and compensate key robotic parameters. However, the dynamic and static parameters of a robot change nonlinearly. It is not possible to acquire a robot's actual parameters and control the absolute pose of the robot with a high accuracy within a large workspace by offline calibration in real-time. This study proposes a real-time online absolute pose steering control method for an industrial robot based on six degrees of freedom laser tracking measurement, which adopts comprehensive compensation and correction of differential movement variables. First, the pose steering control system and robot kinematics error model are constructed, and then the pose error compensation mechanism and algorithm are introduced in detail. By accurately achieving the position and orientation of the robot end-tool, mapping the computed Jacobian matrix of the joint variable and correcting the joint variable, the real-time online absolute pose compensation for an industrial robot is accurately implemented in simulations and experimental tests. The average positioning error is 0.048 mm and orientation accuracy is better than 0.01 deg. The results demonstrate that the proposed method is feasible, and the online absolute accuracy of a robot is sufficiently enhanced.

Quantum steering in cascaded four-wave mixing processes.

PubMed

Wang, Li; Lv, Shuchao; Jing, Jietai

2017-07-24

Quantum steering is used to describe the "spooky action-at-a-distance" nonlocality raised in the Einstein-Podolsky-Rosen (EPR) paradox, which is important for understanding entanglement distribution and constructing quantum networks. Here, in this paper, we study an experimentally feasible scheme for generating quantum steering based on cascaded four-wave-mixing (FWM) processes in hot rubidium (Rb) vapor. Quantum steering, including bipartite steering and genuine tripartite steering among the output light fields, is theoretically analyzed. We find the corresponding gain regions in which the bipartite and tripartite steering exist. The results of bipartite steering can be used to establish a hierarchical steering model in which one beam can steer the other two beams in the whole gain region; however, the other two beams cannot steer the first beam simultaneously. Moreover, the other two beams cannot steer with each other in the whole gain region. More importantly, we investigate the gain dependence of the existence of the genuine tripartite steering and we find that the genuine tripartite steering exists in most of the whole gain region in the ideal case. Also we discuss the effect of losses on the genuine tripartite steering. Our results pave the way to experimental demonstration of quantum steering in cascaded FWM process.

Insect-controlled Robot: A Mobile Robot Platform to Evaluate the Odor-tracking Capability of an Insect.

PubMed

Ando, Noriyasu; Emoto, Shuhei; Kanzaki, Ryohei

2016-12-19

Robotic odor source localization has been a challenging area and one to which biological knowledge has been expected to contribute, as finding odor sources is an essential task for organism survival. Insects are well-studied organisms with regard to odor tracking, and their behavioral strategies have been applied to mobile robots for evaluation. This "bottom-up" approach is a fundamental way to develop biomimetic robots; however, the biological analyses and the modeling of behavioral mechanisms are still ongoing. Therefore, it is still unknown how such a biological system actually works as the controller of a robotic platform. To answer this question, we have developed an insect-controlled robot in which a male adult silkmoth (Bombyx mori) drives a robot car in response to odor stimuli; this can be regarded as a prototype of a future insect-mimetic robot. In the cockpit of the robot, a tethered silkmoth walked on an air-supported ball and an optical sensor measured the ball rotations. These rotations were translated into the movement of the two-wheeled robot. The advantage of this "hybrid" approach is that experimenters can manipulate any parameter of the robot, which enables the evaluation of the odor-tracking capability of insects and provides useful suggestions for robotic odor-tracking. Furthermore, these manipulations are non-invasive ways to alter the sensory-motor relationship of a pilot insect and will be a useful technique for understanding adaptive behaviors.

Energy efficiency of mobile soft robots.

PubMed

Shui, Langquan; Zhu, Liangliang; Yang, Zhe; Liu, Yilun; Chen, Xi

2017-11-15

The performance of mobile soft robots is usually characterized by their locomotion/velocity efficiency, whereas the energy efficiency is a more intrinsic and fundamental criterion for the performance evaluation of independent or integrated soft robots. In this work, a general framework is established to evaluate the energy efficiency of mobile soft robots by considering the efficiency of the energy source, actuator and locomotion, and some insights for improving the efficiency of soft robotic systems are presented. Proposed as the ratio of the desired locomotion kinetic energy to the input mechanical energy, the energy efficiency of locomotion is found to play a critical role in determining the overall energy efficiency of soft robots. Four key factors related to the locomotion energy efficiency are identified, that is, the locomotion modes, material properties, geometric sizes, and actuation states. It is found that the energy efficiency of most mobile soft robots reported in the literature is surprisingly low (mostly below 0.1%), due to the inefficient mechanical energy that essentially does not contribute to the desired locomotion. A comparison of the locomotion energy efficiency for several representative locomotion modes in the literature is presented, showing a descending ranking as: jumping ≫ fish-like swimming > snake-like slithering > rolling > rising/turning over > inchworm-like inching > quadruped gait > earthworm-like squirming. Besides, considering the same locomotion mode, soft robots with lower stiffness, higher density and larger size tend to have higher locomotion energy efficiency. Moreover, a periodic pulse actuation instead of a continuous actuation mode may significantly reduce the input mechanical energy, thus improving the locomotion energy efficiency, especially when the pulse actuation matches the resonant states of the soft robots. The results presented herein indicate a large and necessary space for improving the locomotion energy

Obstacle negotiation control for a mobile robot suspended on overhead ground wires by optoelectronic sensors

NASA Astrophysics Data System (ADS)

Zheng, Li; Yi, Ruan

2009-11-01

Power line inspection and maintenance already benefit from developments in mobile robotics. This paper presents mobile robots capable of crossing obstacles on overhead ground wires. A teleoperated robot realizes inspection and maintenance tasks on power transmission line equipment. The inspection robot is driven by 11 motor with two arms, two wheels and two claws. The inspection robot is designed to realize the function of observation, grasp, walk, rolling, turn, rise, and decline. This paper is oriented toward 100% reliable obstacle detection and identification, and sensor fusion to increase the autonomy level. An embedded computer based on PC/104 bus is chosen as the core of control system. Visible light camera and thermal infrared Camera are both installed in a programmable pan-and-tilt camera (PPTC) unit. High-quality visual feedback rapidly becomes crucial for human-in-the-loop control and effective teleoperation. The communication system between the robot and the ground station is based on Mesh wireless networks by 700 MHz bands. An expert system programmed with Visual C++ is developed to implement the automatic control. Optoelectronic laser sensors and laser range scanner were installed in robot for obstacle-navigation control to grasp the overhead ground wires. A novel prototype with careful considerations on mobility was designed to inspect the 500KV power transmission lines. Results of experiments demonstrate that the robot can be applied to execute the navigation and inspection tasks.

Estimation of automobile-driver describing function from highway tests using the double steering wheel

NASA Technical Reports Server (NTRS)

Delp, P.; Crossman, E. R. F. W.; Szostak, H.

1972-01-01

The automobile-driver describing function for lateral position control was estimated for three subjects from frequency response analysis of straight road test results. The measurement procedure employed an instrumented full size sedan with known steering response characteristics, and equipped with a lateral lane position measuring device based on video detection of white stripe lane markings. Forcing functions were inserted through a servo driven double steering wheel coupling the driver to the steering system proper. Random appearing, Gaussian, and transient time functions were used. The quasi-linear models fitted to the random appearing input frequency response characterized the driver as compensating for lateral position error in a proportional, derivative, and integral manner. Similar parameters were fitted to the Gabor transformed frequency response of the driver to transient functions. A fourth term corresponding to response to lateral acceleration was determined by matching the time response histories of the model to the experimental results. The time histories show evidence of pulse-like nonlinear behavior during extended response to step transients which appear as high frequency remnant power.

Simulation development and evaluation of an improved longitudinal velocity vector control wheel steering mode and electronic display format

NASA Technical Reports Server (NTRS)

Steinmetz, G. G.

1980-01-01

Using simulation, an improved longitudinal velocity vector control wheel steering mode and an improved electronic display format for an advanced flight system were developed and tested. Guidelines for the development phase were provided by test pilot critique summaries of the previous system. The results include performances from computer generated step column inputs across the full airplane speed and configuration envelope, as well as piloted performance results taken from a reference line tracking task and an approach to landing task conducted under various environmental conditions. The analysis of the results for the reference line tracking and approach to landing tasks indicates clearly detectable improvement in pilot tracking accuracy with a reduction in physical workload. The original objectives of upgrading the longitudinal axis of the velocity vector control wheel steering mode were successfully met when measured against the test pilot critique summaries and the original purpose outlined for this type of augment control mode.

Curb Mounting, Vertical Mobility, and Inverted Mobility on Rough Surfaces Using Microspine-Enabled Robots

NASA Technical Reports Server (NTRS)

Parness, Aaron

2012-01-01

Three robots that extend microspine technology to enable advanced mobility are presented. First, the Durable Reconnaissance and Observation Platform (DROP) and the ReconRobotics Scout platform use a new rotary configuration of microspines to provide improved soldier-portable reconnaissance by moving rapidly over curbs and obstacles, transitioning from horizontal to vertical surfaces, climbing rough walls and surviving impacts. Next, the four-legged LEMUR robot uses new configurations of opposed microspines to anchor to both manmade and natural rough surfaces. Using these anchors as feet enables mobility in unstructured environments, from urban disaster areas to deserts and caves.

Hopping robot

DOEpatents

Spletzer, Barry L.; Fischer, Gary J.; Marron, Lisa C.; Martinez, Michael A.; Kuehl, Michael A.; Feddema, John T.

2001-01-01

The present invention provides a hopping robot that includes a misfire tolerant linear actuator suitable for long trips, low energy steering and control, reliable low energy righting, miniature low energy fuel control. The present invention provides a robot with hopping mobility, capable of traversing obstacles significant in size relative to the robot and capable of operation on unpredictable terrain over long range. The present invention further provides a hopping robot with misfire-tolerant combustion actuation, and with combustion actuation suitable for use in oxygen-poor environments.

Compliant-linkage kinematic design for multi-degree-of-freedom mobile robots

NASA Astrophysics Data System (ADS)

Borenstein, Johann

1993-05-01

Multi-degree-of-freedom (MDOF) vehicles have many potential advantages over conventional (i.e., 2-DOF) vehicles. For example, MDOF vehicles can travel sideways and they can negotiate tight turns more easily. In addition, some MDOF designs provide better payload capability, better traction, and improved static and dynamic stability. However, MDOF vehicles with more than three degrees-of-freedom are difficult to control because of their overconstrained nature. These difficulties translate into severe wheel slippage or jerky motion under certain driving conditions. In the past, these problems limited the use of MDOF vehicles to applications where the vehicle would follow a guide-wire, which would correct wheel slippage and control errors. By contrast, autonomous or semi-autonomous mobile robots usually rely on dead-reckoning between periodic absolute position updates and their performance is diminished by excessive wheel slippage. This paper introduces a new concept in the kinematic design of MDOF vehicles. This concept is based on the provision of a compliant linkage between drive wheels or drive axles. Simulation results indicate that compliant linkage allows to overcome the control problems found in conventional MDOF vehicles and reduces the amount of wheel slippage to the same level (or less) than the amount of slippage found on a comparable 2-DOF vehicle.

Steering system for a train of rail-less vehicles

DOEpatents

Voight, Edward T.

1983-01-01

A steering system for use with a multiple vehicle train permits tracking without rails of one vehicle after another. This system is particularly useful for moving conveyor systems into and out of curved paths of room and pillar underground mine installations. The steering system features an elongated steering bar pivotally connected to each of adjacent vehicles at end portions of the bar permitting angular orientation of each vehicle in respect to the steering bar and other vehicles. Each end portion of the steering bar is linked to the near pair of vehicle wheels through wheel yoke pivot arms about king pin type pivots. Movement of the steering bar about its pivotal connection provides proportional turning of the wheels to effect steering and tracking of one vehicle following another in both forward and reverse directions.

New regression model for predicting hand-arm vibration (HAV) of Malaysian Army (MA) three-tonne truck steering wheels.

PubMed

Aziz, Shamsul Akmar Ab; Nuawi, Mohd Zaki; Nor, Mohd Jailani Mohd

2015-01-01

The objective of this study was to present a new method for determination of hand-arm vibration (HAV) in Malaysian Army (MA) three-tonne truck steering wheels based on changes in vehicle speed using regression model and the statistical analysis method known as Integrated Kurtosis-Based Algorithm for Z-Notch Filter Technique Vibro (I-kaz Vibro). The test was conducted for two different road conditions, tarmac and dirt roads. HAV exposure was measured using a Brüel & Kjær Type 3649 vibration analyzer, which is capable of recording HAV exposures from steering wheels. The data was analyzed using I-kaz Vibro to determine the HAV values in relation to varying speeds of a truck and to determine the degree of data scattering for HAV data signals. Based on the results obtained, HAV experienced by drivers can be determined using the daily vibration exposure A(8), I-kaz Vibro coefficient (Ƶ(v)(∞)), and the I-kaz Vibro display. The I-kaz Vibro displays also showed greater scatterings, indicating that the values of Ƶ(v)(∞) and A(8) were increasing. Prediction of HAV exposure was done using the developed regression model and graphical representations of Ƶ(v)(∞). The results of the regression model showed that Ƶ(v)(∞) increased when the vehicle speed and HAV exposure increased. For model validation, predicted and measured noise exposures were compared, and high coefficient of correlation (R(2)) values were obtained, indicating that good agreement was obtained between them. By using the developed regression model, we can easily predict HAV exposure from steering wheels for HAV exposure monitoring.

Adaptive Trajectory Tracking of Nonholonomic Mobile Robots Using Vision-Based Position and Velocity Estimation.

PubMed

Li, Luyang; Liu, Yun-Hui; Jiang, Tianjiao; Wang, Kai; Fang, Mu

2018-02-01

Despite tremendous efforts made for years, trajectory tracking control (TC) of a nonholonomic mobile robot (NMR) without global positioning system remains an open problem. The major reason is the difficulty to localize the robot by using its onboard sensors only. In this paper, a newly designed adaptive trajectory TC method is proposed for the NMR without its position, orientation, and velocity measurements. The controller is designed on the basis of a novel algorithm to estimate position and velocity of the robot online from visual feedback of an omnidirectional camera. It is theoretically proved that the proposed algorithm yields the TC errors to asymptotically converge to zero. Real-world experiments are conducted on a wheeled NMR to validate the feasibility of the control system.

49 CFR 570.7 - Steering systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 6 2011-10-01 2011-10-01 false Steering systems. 570.7 Section 570.7... Pounds or Less § 570.7 Steering systems. (a) System play. Lash or free play in the steering system shall... in the steering system. Table 1—Steering System Free Play Values Steering wheel diameter (inches...

49 CFR 570.7 - Steering systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 6 2012-10-01 2012-10-01 false Steering systems. 570.7 Section 570.7... Pounds or Less § 570.7 Steering systems. (a) System play. Lash or free play in the steering system shall... in the steering system. Table 1—Steering System Free Play Values Steering wheel diameter (inches...

49 CFR 570.7 - Steering systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 6 2014-10-01 2014-10-01 false Steering systems. 570.7 Section 570.7... Pounds or Less § 570.7 Steering systems. (a) System play. Lash or free play in the steering system shall... in the steering system. Table 1—Steering System Free Play Values Steering wheel diameter (inches...

49 CFR 570.7 - Steering systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 6 2010-10-01 2010-10-01 false Steering systems. 570.7 Section 570.7... Pounds or Less § 570.7 Steering systems. (a) System play. Lash or free play in the steering system shall... in the steering system. Table 1—Steering System Free Play Values Steering wheel diameter (inches...

A Novel Mittag-Leffler Kernel Based Hybrid Fault Diagnosis Method for Wheeled Robot Driving System.

PubMed

Yuan, Xianfeng; Song, Mumin; Zhou, Fengyu; Chen, Zhumin; Li, Yan

2015-01-01

The wheeled robots have been successfully applied in many aspects, such as industrial handling vehicles, and wheeled service robots. To improve the safety and reliability of wheeled robots, this paper presents a novel hybrid fault diagnosis framework based on Mittag-Leffler kernel (ML-kernel) support vector machine (SVM) and Dempster-Shafer (D-S) fusion. Using sensor data sampled under different running conditions, the proposed approach initially establishes multiple principal component analysis (PCA) models for fault feature extraction. The fault feature vectors are then applied to train the probabilistic SVM (PSVM) classifiers that arrive at a preliminary fault diagnosis. To improve the accuracy of preliminary results, a novel ML-kernel based PSVM classifier is proposed in this paper, and the positive definiteness of the ML-kernel is proved as well. The basic probability assignments (BPAs) are defined based on the preliminary fault diagnosis results and their confidence values. Eventually, the final fault diagnosis result is archived by the fusion of the BPAs. Experimental results show that the proposed framework not only is capable of detecting and identifying the faults in the robot driving system, but also has better performance in stability and diagnosis accuracy compared with the traditional methods.

A Robust Control of Two-Wheeled Mobile Manipulator with Underactuated Joint by Nonlinear Backstepping Method

NASA Astrophysics Data System (ADS)

Acar, Cihan; Murakami, Toshiyuki

In this paper, a robust control of two-wheeled mobile manipulator with underactuated joint is considered. Two-wheeled mobile manipulators are dynamically balanced two-wheeled driven systems that do not have any caster or extra wheels to stabilize their body. Two-wheeled mobile manipulators mainly have an important feature that makes them more flexible and agile than the statically stable mobile manipulators. However, two-wheeled mobile manipulator is an underactuated system due to its two-wheeled structure. Therefore, it is required to stabilize the underactuated passive body and, at the same time, control the position of the center of gravity (CoG) of the manipulator in this system. To realize this, nonlinear backstepping based control method with virtual double inverted pendulum model is proposed in this paper. Backstepping is used with sliding mode to increase the robustness of the system against modeling errors and other perturbations. Then robust acceleration control is also achieved by utilizing disturbance observer. Performance of the proposed method is evaluated by several experiments.

Embedded object concept: case balancing two-wheeled robot

NASA Astrophysics Data System (ADS)

Vallius, Tero; Röning, Juha

2007-09-01

This paper presents the Embedded Object Concept (EOC) and a telepresence robot system which is a test case for the EOC. The EOC utilizes common object-oriented methods used in software by applying them to combined Lego-like software-hardware entities. These entities represent objects in object-oriented design methods, and they are the building blocks of embedded systems. The goal of the EOC is to make the designing of embedded systems faster and easier. This concept enables people without comprehensive knowledge in electronics design to create new embedded systems, and for experts it shortens the design time of new embedded systems. We present the current status of a telepresence robot created with Atomi-objects, which is the name for our implementation of the embedded objects. The telepresence robot is a relatively complex test case for the EOC. The robot has been constructed using incremental device development, which is made possible by the architecture of the EOC. The robot contains video and audio exchange capability and a controlling system for driving with two wheels. The robot consists of Atomi-objects, demonstrating the suitability of the EOC for prototyping and easy modifications, and proving the capabilities of the EOC by realizing a function that normally requires a computer. The computer counterpart is a regular PC with audio and video capabilities running with a robot control application. The robot is functional and successfully tested.

Efficient direct yaw moment control: tyre slip power loss minimisation for four-independent wheel drive vehicle

NASA Astrophysics Data System (ADS)

Kobayashi, Takao; Katsuyama, Etsuo; Sugiura, Hideki; Ono, Eiichi; Yamamoto, Masaki

2018-05-01

This paper proposes an efficient direct yaw moment control (DYC) capable of minimising tyre slip power loss on contact patches for a four-independent wheel drive vehicle. Simulations identified a significant power loss reduction with a direct yaw moment due to a change in steer characteristics during acceleration or deceleration while turning. Simultaneously, the vehicle motion can be stabilised. As a result, the proposed control method can ensure compatibility between vehicle dynamics performance and energy efficiency. This paper also describes the results of a full-vehicle simulation that was conducted to examine the effectiveness of the proposed DYC.

A study on a wheel-based stair-climbing robot with a hopping mechanism

NASA Astrophysics Data System (ADS)

Kikuchi, Koki; Sakaguchi, Keisuke; Sudo, Takayuki; Bushida, Naoki; Chiba, Yasuhiro; Asai, Yuji

2008-08-01

In this study, we propose a simple hopping mechanism using the vibration of a two-degree-of-freedom system for a wheel-based stair-climbing robot. The robot, consisting of two bodies connected by springs and a wire, hops by releasing energy stored in the springs and quickly travels using wheels mounted in its lower body. The trajectories of the bodies during hopping change in accordance with the design parameters, such as the reduced mass of the two bodies, the mass ratio between the upper and lower bodies, the spring constant, the control parameters such as the initial contraction of the spring and the wire tension. This property allows the robot to quickly and economically climb up and down stairs, leap over obstacles, and landing softly without complex control. In this paper, the characteristics of hopping motion for the design and control parameters are clarified by both numerical simulations and experiments. Furthermore, using the robot design based on the results the abilities to hop up and down a step, leap over a cable, and land softly are demonstrated.

Mobility Performance Algorithms for Small Unmanned Ground Vehicles

DTIC Science & Technology

2009-05-01

obstacles need to be developed; specifically, models and data for wheeled vehicle skid steering, interior building floor and roof surfaces, and stair ...an 80-lb SUGV; PackBot® at 50 lb, and GatorTM at 2500 lb. Additionally, the FCS projects that 40% of the military fleet may eventually be robotic ...sensor input analysis and decision-making time. Fields (2002a) discusses representing interaction of humans and robots in the OneSAF Testbed Baseline

Tandem robot control system and method for controlling mobile robots in tandem

DOEpatents

Hayward, David R.; Buttz, James H.; Shirey, David L.

2002-01-01

A control system for controlling mobile robots provides a way to control mobile robots, connected in tandem with coupling devices, to navigate across difficult terrain or in closed spaces. The mobile robots can be controlled cooperatively as a coupled system in linked mode or controlled individually as separate robots.

A novel traveling wave piezoelectric actuated tracked mobile robot utilizing friction effect

NASA Astrophysics Data System (ADS)

Wang, Liang; Shu, Chengyou; Jin, Jiamei; Zhang, Jianhui

2017-03-01

A novel traveling wave piezoelectric-actuated tracked mobile robot with potential application to robotic rovers was proposed and investigated in this study. The proposed tracked mobile robot is composed of a parallelogram-frame-structure piezoelectric transducer with four rings and a metal track. Utilizing the converse piezoelectric and friction effects, traveling waves were propagated in the rings and then the metal track was actuated by the piezoelectric transducer. Compared with traditional tracked mechanisms, the proposed tracked mobile robot has a simpler and more compact structure without lubricant, which eliminates the problem of lubricant volatilization and deflation, thus, it could be operated in the vacuum environment. Dynamic characteristics were simulated and measured to reveal the mechanism of actuating track of the piezoelectric transducer. Experimental investigations of the traveling wave piezoelectric-actuated tracked mobile robot were then carried out, and the results indicated that the robot prototype with a pair of exciting voltages of 460 Vpp is able to achieve a maximum velocity of 57 mm s-1 moving on the foam plate and possesses the obstacle crossing capability with a maximum height of 27 mm. The proposed tracked mobile robot exhibits potential to be the driving system of robotic rovers.

Fault-tolerant control of electric vehicles with in-wheel motors using actuator-grouping sliding mode controllers

NASA Astrophysics Data System (ADS)

Li, Boyuan; Du, Haiping; Li, Weihua

2016-05-01

Although electric vehicles with in-wheel motors have been regarded as one of the promising vehicle architectures in recent years, the probability of in-wheel motor fault is still a crucial issue due to the system complexity and large number of control actuators. In this study, a modified sliding mode control (SMC) is applied to achieve fault-tolerant control of electric vehicles with four-wheel-independent-steering (4WIS) and four-wheel-independent-driving (4WID). Unlike in traditional SMC, in this approach the steering geometry is re-arranged according to the location of faulty wheels in the modified SMC. Three SMC control laws for longitudinal velocity control, lateral velocity control and yaw rate control are designed based on specific vehicle motion scenarios. In addition the actuator-grouping SMC method is proposed so that driving actuators are grouped and each group of actuators can be used to achieve the specific control target, which avoids the strong coupling effect between each control target. Simulation results prove that the proposed modified SMC can achieve good vehicle dynamics control performance in normal driving and large steering angle turning scenarios. In addition, the proposed actuator-grouping SMC can solve the coupling effect of different control targets and the control performance is improved.

49 CFR 393.209 - Steering wheel systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS PARTS AND ACCESSORIES...) Steering column. The steering column must be securely fastened. (d) Steering system. Universal joints and...

49 CFR 393.209 - Steering wheel systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS PARTS AND ACCESSORIES...) Steering column. The steering column must be securely fastened. (d) Steering system. Universal joints and...

49 CFR 393.209 - Steering wheel systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS PARTS AND ACCESSORIES...) Steering column. The steering column must be securely fastened. (d) Steering system. Universal joints and...

49 CFR 393.209 - Steering wheel systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS PARTS AND ACCESSORIES...) Steering column. The steering column must be securely fastened. (d) Steering system. Universal joints and...

49 CFR 393.209 - Steering wheel systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS PARTS AND ACCESSORIES...) Steering column. The steering column must be securely fastened. (d) Steering system. Universal joints and...

A Novel Mittag-Leffler Kernel Based Hybrid Fault Diagnosis Method for Wheeled Robot Driving System

PubMed Central

Yuan, Xianfeng; Song, Mumin; Chen, Zhumin; Li, Yan

2015-01-01

The wheeled robots have been successfully applied in many aspects, such as industrial handling vehicles, and wheeled service robots. To improve the safety and reliability of wheeled robots, this paper presents a novel hybrid fault diagnosis framework based on Mittag-Leffler kernel (ML-kernel) support vector machine (SVM) and Dempster-Shafer (D-S) fusion. Using sensor data sampled under different running conditions, the proposed approach initially establishes multiple principal component analysis (PCA) models for fault feature extraction. The fault feature vectors are then applied to train the probabilistic SVM (PSVM) classifiers that arrive at a preliminary fault diagnosis. To improve the accuracy of preliminary results, a novel ML-kernel based PSVM classifier is proposed in this paper, and the positive definiteness of the ML-kernel is proved as well. The basic probability assignments (BPAs) are defined based on the preliminary fault diagnosis results and their confidence values. Eventually, the final fault diagnosis result is archived by the fusion of the BPAs. Experimental results show that the proposed framework not only is capable of detecting and identifying the faults in the robot driving system, but also has better performance in stability and diagnosis accuracy compared with the traditional methods. PMID:26229526

An improved lateral control wheel steering law for the Transport Systems Research Vehicle (TSRV)

NASA Technical Reports Server (NTRS)

Ragsdale, W. A.

1992-01-01

A lateral control wheel steering law with improved performance was developed for the Transport Systems Research Vehicle (TSRV) simulation and used in the Microwave Landing System research project. The control law converted rotational hand controller inputs into roll rate commands, manipulated ailerons, spoilers, and the rudder to achieve the desired roll rates. The system included automatic turn coordination, track angle hold, and autopilot/autoland modes. The resulting control law produced faster roll rates (15 degrees/sec), quicker response to command reversals, and safer bank angle limits, while using a more concise program code.

Training toddlers seated on mobile robots to drive indoors amidst obstacles.

PubMed

Chen, Xi; Ragonesi, Christina; Galloway, James C; Agrawal, Sunil K

2011-06-01

Mobility is a causal factor in development. Children with mobility impairments may rely upon power mobility for independence and thus require advanced driving skills to function independently. Our previous studies show that while infants can learn to drive directly to a goal using conventional joysticks in several months of training, they are unable in this timeframe to acquire the advanced skill to avoid obstacles while driving. Without adequate driving training, children are unable to explore the environment safely, the consequences of which may in turn increase their risk for developmental delay. The goal of this research therefore is to train children seated on mobile robots to purposefully and safely drive indoors. In this paper, we present results where ten typically-developing toddlers are trained to drive a robot within an obstacle course. We also report a case study with a toddler with spina-bifida who cannot independently walk. Using algorithms based on artificial potential fields to avoid obstacles, we create force field on the joystick that trains the children to navigate while avoiding obstacles. In this "assist-as-needed" approach, if the child steers the joystick outside a force tunnel centered on the desired direction, the driver experiences a bias force on the hand. Our results suggest that the use of a force-feedback joystick may yield faster learning than the use of a conventional joystick.

Autonomous mobile robot teams

NASA Technical Reports Server (NTRS)

Agah, Arvin; Bekey, George A.

1994-01-01

This paper describes autonomous mobile robot teams performing tasks in unstructured environments. The behavior and the intelligence of the group is distributed, and the system does not include a central command base or leader. The novel concept of the Tropism-Based Cognitive Architecture is introduced, which is used by the robots in order to produce behavior transforming their sensory information to proper action. The results of a number of simulation experiments are presented. These experiments include worlds where the robot teams must locate, decompose, and gather objects, and defend themselves against hostile predators, while navigating around stationary and mobile obstacles.

Improving Hybrid III injury assessment in steering wheel rim to chest impacts using responses from finite element Hybrid III and human body model.

PubMed

Holmqvist, Kristian; Davidsson, Johan; Mendoza-Vazquez, Manuel; Rundberget, Peter; Svensson, Mats Y; Thorn, Stefan; Törnvall, Fredrik

2014-01-01

The main aim of this study was to improve the quality of injury risk assessments in steering wheel rim to chest impacts when using the Hybrid III crash test dummy in frontal heavy goods vehicle (HGV) collision tests. Correction factors for chest injury criteria were calculated as the model chest injury parameter ratios between finite element (FE) Hybrid III, evaluated in relevant load cases, and the Total Human Model for Safety (THUMS). This is proposed to be used to compensate Hybrid III measurements in crash tests where steering wheel rim to chest impacts occur. The study was conducted in an FE environment using an FE-Hybrid III model and the THUMS. Two impactor shapes were used, a circular hub and a long, thin horizontal bar. Chest impacts at velocities ranging from 3.0 to 6.0 m/s were simulated at 3 impact height levels. A ratio between FE-Hybrid III and THUMS chest injury parameters, maximum chest compression C max, and maximum viscous criterion VC max, were calculated for the different chest impact conditions to form a set of correction factors. The definition of the correction factor is based on the assumption that the response from a circular hub impact to the middle of the chest is well characterized and that injury risk measures are independent of impact height. The current limits for these chest injury criteria were used as a basis to develop correction factors that compensate for the limitations in biofidelity of the Hybrid III in steering wheel rim to chest impacts. The hub and bar impactors produced considerably higher C max and VC max responses in the THUMS compared to the FE-Hybrid III. The correction factor for the responses of the FE-Hybrid III showed that the criteria responses for the bar impactor were consistently overestimated. Ratios based on Hybrid III and THUMS responses provided correction factors for the Hybrid III responses ranging from 0.84 to 0.93. These factors can be used to estimate C max and VC max values when the Hybrid III is

Learning for intelligent mobile robots

NASA Astrophysics Data System (ADS)

Hall, Ernest L.; Liao, Xiaoqun; Alhaj Ali, Souma M.

2003-10-01

Unlike intelligent industrial robots which often work in a structured factory setting, intelligent mobile robots must often operate in an unstructured environment cluttered with obstacles and with many possible action paths. However, such machines have many potential applications in medicine, defense, industry and even the home that make their study important. Sensors such as vision are needed. However, in many applications some form of learning is also required. The purpose of this paper is to present a discussion of recent technical advances in learning for intelligent mobile robots. During the past 20 years, the use of intelligent industrial robots that are equipped not only with motion control systems but also with sensors such as cameras, laser scanners, or tactile sensors that permit adaptation to a changing environment has increased dramatically. However, relatively little has been done concerning learning. Adaptive and robust control permits one to achieve point to point and controlled path operation in a changing environment. This problem can be solved with a learning control. In the unstructured environment, the terrain and consequently the load on the robot"s motors are constantly changing. Learning the parameters of a proportional, integral and derivative controller (PID) and artificial neural network provides an adaptive and robust control. Learning may also be used for path following. Simulations that include learning may be conducted to see if a robot can learn its way through a cluttered array of obstacles. If a situation is performed repetitively, then learning can also be used in the actual application. To reach an even higher degree of autonomous operation, a new level of learning is required. Recently learning theories such as the adaptive critic have been proposed. In this type of learning a critic provides a grade to the controller of an action module such as a robot. The creative control process is used that is "beyond the adaptive critic." A

[Mobile autonomous robots-Possibilities and limits].

PubMed

Maehle, E; Brockmann, W; Walthelm, A

2002-02-01

Besides industrial robots, which today are firmly established in production processes, service robots are becoming more and more important. They shall provide services for humans in different areas of their professional and everyday environment including medicine. Most of these service robots are mobile which requires an intelligent autonomous behaviour. After characterising the different kinds of robots the relevant paradigms of intelligent autonomous behaviour for mobile robots are critically discussed in this paper and illustrated by three concrete examples of robots realized in Lübeck. In addition a short survey of actual kinds of surgical robots as well as an outlook to future developments is given.

Automatic Robotic Steering of Flexible Needles from 3D Ultrasound Images in Phantoms and Ex Vivo Biological Tissue.

PubMed

Mignon, Paul; Poignet, Philippe; Troccaz, Jocelyne

2018-05-29

Robotic control of needle bending aims at increasing the precision of percutaneous procedures. Ultrasound feedback is preferable for its clinical ease of use, cost and compactness but raises needle detection issues. In this paper, we propose a complete system dedicated to robotized guidance of a flexible needle under 3D ultrasound imaging. This system includes a medical robot dedicated to transperineal needle positioning and insertion, a rapid path planning for needle steering using bevel-tip needle natural curvature in tissue, and an ultrasound-based automatic needle detection algorithm. Since ultrasound-based automatic needle steering is often made difficult by the needle localization in biological tissue, we quantify the benefit of using flexible echogenic needles for robotized guidance under 3D ultrasound. The "echogenic" term refers to the etching of microstructures on the needle shaft. We prove that these structures improve needle visibility and detection robustness in ultrasound images. We finally present promising results when reaching targets using needle steering. The experiments were conducted with various needles in different media (synthetic phantoms and ex vivo biological tissue). For instance, with nitinol needles the mean accuracy is 1.2 mm (respectively 3.8 mm) in phantoms (resp. biological tissue).

Passivity-Based Control for Two-Wheeled Robot Stabilization

NASA Astrophysics Data System (ADS)

Uddin, Nur; Aryo Nugroho, Teguh; Agung Pramudito, Wahyu

2018-04-01

A passivity-based control system design for two-wheeled robot (TWR) stabilization is presented. A TWR is a statically-unstable non-linear system. A control system is applied to actively stabilize the TWR. Passivity-based control method is applied to design the control system. The design results in a state feedback control law that makes the TWR closed loop system globally asymptotically stable (GAS). The GAS is proven mathematically. The TWR stabilization is demonstrated through computer simulation. The simulation results show that the designed control system is able to stabilize the TWR.

Steering of an automated vehicle in an unstructured environment

NASA Astrophysics Data System (ADS)

Kanakaraju, Sampath; Shanmugasundaram, Sathish K.; Thyagarajan, Ramesh; Hall, Ernest L.

1999-08-01

The purpose of this paper is to describe a high-level path planning logic, which processes the data from a vision system and an ultrasonic obstacle avoidance system and steers an autonomous mobile robot between obstacles. The test bed was an autonomous root built at University of Cincinnati, and this logic was tested and debugged on this machine. Attempts have already been made to incorporate fuzzy system on a similar robot, and this paper extends them to take advantage of the robot's ZTR capability. Using the integrated vision syste, the vehicle senses its location and orientation. A rotating ultrasonic sensor is used to map the location and size of possible obstacles. With these inputs the fuzzy logic controls the speed and the steering decisions of the robot. With the incorporation of this logic, it has been observed that Bearcat II has been very successful in avoiding obstacles very well. This was achieved in the Ground Robotics Competition conducted by the AUVS in June 1999, where it travelled a distance of 154 feet in a 10ft. wide path ridden with obstacles. This logic proved to be a significant contributing factor in this feat of Bearcat II.

Navigation system for autonomous mapper robots

NASA Astrophysics Data System (ADS)

Halbach, Marc; Baudoin, Yvan

1993-05-01

This paper describes the conception and realization of a fast, robust, and general navigation system for a mobile (wheeled or legged) robot. A database, representing a high level map of the environment is generated and continuously updated. The first part describes the legged target vehicle and the hexapod robot being developed. The second section deals with spatial and temporal sensor fusion for dynamic environment modeling within an obstacle/free space probabilistic classification grid. Ultrasonic sensors are used, others are suspected to be integrated, and a-priori knowledge is treated. US sensors are controlled by the path planning module. The third part concerns path planning and a simulation of a wheeled robot is also presented.

Computed tomography (CT)-compatible remote center of motion needle steering robot: Fusing CT images and electromagnetic sensor data.

PubMed

Shahriari, Navid; Heerink, Wout; van Katwijk, Tim; Hekman, Edsko; Oudkerk, Matthijs; Misra, Sarthak

2017-07-01

Lung cancer is the most common cause of cancer-related death, and early detection can reduce the mortality rate. Patients with lung nodules greater than 10 mm usually undergo a computed tomography (CT)-guided biopsy. However, aligning the needle with the target is difficult and the needle tends to deflect from a straight path. In this work, we present a CT-compatible robotic system, which can both position the needle at the puncture point and also insert and rotate the needle. The robot has a remote-center-of-motion arm which is achieved through a parallel mechanism. A new needle steering scheme is also developed where CT images are fused with electromagnetic (EM) sensor data using an unscented Kalman filter. The data fusion allows us to steer the needle using the real-time EM tracker data. The robot design and the steering scheme are validated using three experimental cases. Experimental Case I and II evaluate the accuracy and CT-compatibility of the robot arm, respectively. In experimental Case III, the needle is steered towards 5 real targets embedded in an anthropomorphic gelatin phantom of the thorax. The mean targeting error for the 5 experiments is 1.78 ± 0.70 mm. The proposed robotic system is shown to be CT-compatible with low targeting error. Small nodule size and large needle diameter are two risk factors that can lead to complications in lung biopsy. Our results suggest that nodules larger than 5 mm in diameter can be targeted using our method which may result in lower complication rate. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

Comparison of manual steering and steering via joystick of a flexible rhino endoscope.

PubMed

Eckl, R; Gumprecht, J J; Strauss, G; Hofer, M; Dietz, A; Lueth, T C

2010-01-01

Flexible endoscopes are used in ENT surgery for examination tasks in cases wherever rigid endoscopes are unsuitable to reach certain positions in the nasal cavity. Until today they are steered by hand and no robotized system has been put into clinical practice. One qualification a robot manipulator system has to fulfill to be accepted is not to create new disadvantages compared to the conventional method in surgery. An important factor is the time needed to steer the new system compared to the time needed to steer the conventional system. In this article a robot manipulator system and an experiment are presented to compare the particular times test persons need to perform a certain task. This approach offers the possibility to benchmark the developed robot manipulator system and future systems for flexible rhino endoscopes.

A soft robot capable of 2D mobility and self-sensing for obstacle detection and avoidance

NASA Astrophysics Data System (ADS)

Qin, Lei; Tang, Yucheng; Gupta, Ujjaval; Zhu, Jian

2018-04-01

Soft robots have shown great potential for surveillance applications due to their interesting attributes including inherent flexibility, extreme adaptability, and excellent ability to move in confined spaces. High mobility combined with the sensing systems that can detect obstacles plays a significant role in performing surveillance tasks. Extensive studies have been conducted on movement mechanisms of traditional hard-bodied robots to increase their mobility. However, there are limited efforts in the literature to explore the mobility of soft robots. In addition, little attempt has been made to study the obstacle-detection capability of a soft mobile robot. In this paper, we develop a soft mobile robot capable of high mobility and self-sensing for obstacle detection and avoidance. This robot, consisting of a dielectric elastomer actuator as the robot body and four electroadhesion actuators as the robot feet, can generate 2D mobility, i.e. translations and turning in a 2D plane, by programming the actuation sequence of the robot body and feet. Furthermore, we develop a self-sensing method which models the robot body as a deformable capacitor. By measuring the real-time capacitance of the robot body, the robot can detect an obstacle when the peak capacitance drops suddenly. This sensing method utilizes the robot body itself instead of external sensors to achieve detection of obstacles, which greatly reduces the weight and complexity of the robot system. The 2D mobility and self-sensing capability ensure the success of obstacle detection and avoidance, which paves the way for the development of lightweight and intelligent soft mobile robots.

Where We Look When We Drive with or without Active Steering Wheel Control

PubMed Central

Mars, Franck; Navarro, Jordan

2012-01-01

Current theories on the role of visuomotor coordination in driving agree that active sampling of the road by the driver informs the arm-motor system in charge of performing actions on the steering wheel. Still under debate, however, is the nature of visual cues and gaze strategies used by drivers. In particular, the tangent point hypothesis, which states that drivers look at a specific point on the inside edge line, has recently become the object of controversy. An alternative hypothesis proposes that drivers orient gaze toward the desired future path, which happens to be often situated in the vicinity of the tangent point. The present study contributed to this debate through the analyses of the distribution of gaze orientation with respect to the tangent point. The results revealed that drivers sampled the roadway in the close vicinity of the tangent point rather than the tangent point proper. This supports the idea that drivers look at the boundary of a safe trajectory envelop near the inside edge line. Furthermore, the study investigated for the first time the reciprocal influence of manual control on gaze control in the context of driving. This was achieved through the comparison of gaze behavior when drivers actively steered the vehicle or when steering was performed by an automatic controller. The results showed an increase in look-ahead fixations in the direction of the bend exit and a small but consistent reduction in the time spent looking in the area of the tangent point when steering was passive. This may be the consequence of a change in the balance between cognitive and sensorimotor anticipatory gaze strategies. It might also reflect bidirectional coordination control between the eye and arm-motor systems, which goes beyond the common assumption that the eyes lead the hands when driving. PMID:22928043

Online Detection of Driver Fatigue Using Steering Wheel Angles for Real Driving Conditions.

PubMed

Li, Zuojin; Li, Shengbo Eben; Li, Renjie; Cheng, Bo; Shi, Jinliang

2017-03-02

This paper presents a drowsiness on-line detection system for monitoring driver fatigue level under real driving conditions, based on the data of steering wheel angles (SWA) collected from sensors mounted on the steering lever. The proposed system firstly extracts approximate entropy (ApEn)featuresfromfixedslidingwindowsonreal-timesteeringwheelanglestimeseries. Afterthat, this system linearizes the ApEn features series through an adaptive piecewise linear fitting using a given deviation. Then, the detection system calculates the warping distance between the linear features series of the sample data. Finally, this system uses the warping distance to determine the drowsiness state of the driver according to a designed binary decision classifier. The experimental data were collected from 14.68 h driving under real road conditions, including two fatigue levels: "wake" and "drowsy". The results show that the proposed system is capable of working online with an average 78.01% accuracy, 29.35% false detections of the "awake" state, and 15.15% false detections of the "drowsy" state. The results also confirm that the proposed method based on SWA signal is valuable for applications in preventing traffic accidents caused by driver fatigue.

Line following using a two camera guidance system for a mobile robot

NASA Astrophysics Data System (ADS)

Samu, Tayib; Kelkar, Nikhal; Perdue, David; Ruthemeyer, Michael A.; Matthews, Bradley O.; Hall, Ernest L.

1996-10-01

Automated unmanned guided vehicles have many potential applications in manufacturing, medicine, space and defense. A mobile robot has been designed for the 1996 Automated Unmanned Vehicle Society competition which was held in Orlando, Florida on July 15, 1996. The competition required the vehicle to follow solid and dashed lines around an approximately 800 ft. path while avoiding obstacles, overcoming terrain changes such as inclines and sand traps, and attempting to maximize speed. The purpose of this paper is to describe the algorithm developed for the line following. The line following algorithm images two windows and locates their centroid and with the knowledge that the points are on the ground plane, a mathematical and geometrical relationship between the image coordinates of the points and their corresponding ground coordinates are established. The angle of the line and minimum distance from the robot centroid are then calculated and used in the steering control. Two cameras are mounted on the robot with a camera on each side. One camera guides the robot and when it loses track of the line on its side, the robot control system automatically switches to the other camera. The test bed system has provided an educational experience for all involved and permits understanding and extending the state of the art in autonomous vehicle design.

Guarded Motion for Mobile Robots

DOE Office of Scientific and Technical Information (OSTI.GOV)

2005-03-30

The Idaho National Laboratory (INL) has created codes that ensure that a robot will come to a stop at a precise, specified distance from any obstacle regardless of the robot's initial speed, its physical characteristics, and the responsiveness of the low-level motor control schema. This Guarded Motion for Mobile Robots system iteratively adjusts the robot's action in response to information about the robot's environment.

Smart mobile robot system for rubbish collection

NASA Astrophysics Data System (ADS)

Ali, Mohammed A. H.; Sien Siang, Tan

2018-03-01

This paper records the research and procedures of developing a smart mobility robot with detection system to collect rubbish. The objective of this paper is to design a mobile robot that can detect and recognize medium-size rubbish such as drinking cans. Besides that, the objective is also to design a mobile robot with the ability to estimate the position of rubbish from the robot. In addition, the mobile robot is also able to approach the rubbish based on position of rubbish. This paper explained about the types of image processing, detection and recognition methods and image filters. This project implements RGB subtraction method as the prior system. Other than that, algorithm for distance measurement based on image plane is implemented in this project. This project is limited to use computer webcam as the sensor. Secondly, the robot is only able to approach the nearest rubbish in the same views of camera vision and any rubbish that contain RGB colour components on its body.

Stair-climbing capabilities of USU's T3 ODV mobile robot

NASA Astrophysics Data System (ADS)

Robinson, D. Reed; Wood, Carl G.

2001-09-01

A six-wheeled autonomous omni-directional vehicle (ODV) called T3 has been developed at Utah State University's (USU) Center for Self-Organizing and Intelligent Systems (CSOIS). This paper focuses on T3's ability to climb stairs using its unique configuration of 6 independently driven and steered wheels and active suspension height control. The ability of T3, or any similar vehicle, to climb stairs is greatly dependent on the chassis orientation relative to the stairs. Stability criteria is developed for any vehicle dimensions and orientation, on any staircase. All possible yaw and pitch angles on various staircases are evaluated to find vehicle orientations that will allow T3 to climb with the largest margin of stability. Different controller types are investigated for controlling vertical wheel movement with the objective of keeping all wheels in contact with the stairs, providing smooth load transfer between loaded and unloaded wheels, and maintaining optimum chassis pitch and roll angles. A controller is presented that uses feedback from wheel loading, vertical wheel position, and chassis orientation sensors. The implementation of the controller is described, and T3's stair climbing performance is presented and evaluated.

Video rate color region segmentation for mobile robotic applications

NASA Astrophysics Data System (ADS)

de Cabrol, Aymeric; Bonnin, Patrick J.; Hugel, Vincent; Blazevic, Pierre; Chetto, Maryline

2005-08-01

Color Region may be an interesting image feature to extract for visual tasks in robotics, such as navigation and obstacle avoidance. But, whereas numerous methods are used for vision systems embedded on robots, only a few use this segmentation mainly because of the processing duration. In this paper, we propose a new real-time (ie. video rate) color region segmentation followed by a robust color classification and a merging of regions, dedicated to various applications such as RoboCup four-legged league or an industrial conveyor wheeled robot. Performances of this algorithm and confrontation with other methods, in terms of result quality and temporal performances are provided. For better quality results, the obtained speed up is between 2 and 4. For same quality results, the it is up to 10. We present also the outlines of the Dynamic Vision System of the CLEOPATRE Project - for which this segmentation has been developed - and the Clear Box Methodology which allowed us to create the new color region segmentation from the evaluation and the knowledge of other well known segmentations.

Power transmission device for four wheel drive vehicle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iwatsuki, T.; Kawamoto, M.; Kano, T.

This patent describes a power transmission device with an improved differential motion limiting mechanism for a four wheel drive vehicle having automatic transmission means, front wheel differential gear means, differential motion limiting means and transfer unit means including center differential gear means, comprising: a first gear mount casing having a gear adapted to mesh with an output of a transmission; a differential motion limiting device arranged together with a front wheel differential gear in the first gear mount casing. The front wheel differential gear having a first diff-carrier and the differential motion limiting device comprising a hydraulic friction clutch formore » engaging and disengaging the first gear mount casing with the first diff-carrier of the front wheel differential gear; a second gear mount casing disposed coaxially with respect to the first gear mount casing; and a transfer unit including a center differential gear arranged in the second gear mount casing, the center differential gear comprising a second diff-carrier coupled with the first gear mount casing, a first side gear coupled with the first diff-carrier of the front wheel differential gear, and a second side gear coupled with the second gear mount casing for transmitting power to the rear wheels.« less

Effect of wheelchair design on wheeled mobility and propulsion efficiency in less-resourced settings

PubMed Central

2017-01-01

Background Wheelchair research includes both qualitative and quantitative approaches, primarily focuses on functionality and skill performance and is often limited to short testing periods. This is the first study to use the combination of a performance test (i.e. wheelchair propulsion test) and a multiple-day mobility assessment to evaluate wheelchair designs in rural areas of a developing country. Objectives Test the feasibility of using wheel-mounted accelerometers to document bouts of wheeled mobility data in rural settings and use these data to compare how patients respond to different wheelchair designs. Methods A quasi-experimental, pre- and post-test design was used to test the differences between locally manufactured wheelchairs (push rim and tricycle) and an imported intervention product (dual-lever propulsion wheelchair). A one-way repeated measures analysis of variance was used to interpret propulsion and wheeled mobility data. Results There were no statistical differences in bouts of mobility between the locally manufactured and intervention product, which was explained by high amounts of variability within the data. With regard to the propulsion test, push rim users were significantly more efficient when using the intervention product compared with tricycle users. Conclusion Use of wheel-mounted accelerometers as a means to test user mobility proved to be a feasible methodology in rural settings. Variability in wheeled mobility data could be decreased with longer acclimatisation periods. The data suggest that push rim users experience an easier transition to a dual-lever propulsion system. PMID:28936416

Effect of wheelchair design on wheeled mobility and propulsion efficiency in less-resourced settings.

PubMed

Stanfill, Christopher J; Jensen, Jody L

2017-01-01

Wheelchair research includes both qualitative and quantitative approaches, primarily focuses on functionality and skill performance and is often limited to short testing periods. This is the first study to use the combination of a performance test (i.e. wheelchair propulsion test) and a multiple-day mobility assessment to evaluate wheelchair designs in rural areas of a developing country. Test the feasibility of using wheel-mounted accelerometers to document bouts of wheeled mobility data in rural settings and use these data to compare how patients respond to different wheelchair designs. A quasi-experimental, pre- and post-test design was used to test the differences between locally manufactured wheelchairs (push rim and tricycle) and an imported intervention product (dual-lever propulsion wheelchair). A one-way repeated measures analysis of variance was used to interpret propulsion and wheeled mobility data. There were no statistical differences in bouts of mobility between the locally manufactured and intervention product, which was explained by high amounts of variability within the data. With regard to the propulsion test, push rim users were significantly more efficient when using the intervention product compared with tricycle users. Use of wheel-mounted accelerometers as a means to test user mobility proved to be a feasible methodology in rural settings. Variability in wheeled mobility data could be decreased with longer acclimatisation periods. The data suggest that push rim users experience an easier transition to a dual-lever propulsion system.

A review of physical security robotics at Sandia National Laboratories

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roerig, S.C.

1990-01-01

As an outgrowth of research into physical security technologies, Sandia is investigating the role of robotics in security systems. Robotics may allow more effective utilization of guard forces, especially in scenarios where personnel would be exposed to harmful environments. Robots can provide intrusion detection and assessment functions for failed sensors or transient assets, can test existing fixed site sensors, and can gather additional intelligence and dispense delaying elements. The Robotic Security Vehicle (RSV) program for DOE/OSS is developing a fieldable prototype for an exterior physical security robot based upon a commercial four wheel drive vehicle. The RSV will be capablemore » of driving itself, being driven remotely, or being driven by an onboard operator around a site and will utilize its sensors to alert an operator to unusual conditions. The Remote Security Station (RSS) program for the Defense Nuclear Agency is developing a proof-of-principle robotic system which will be used to evaluate the role, and associated cost, of robotic technologies in exterior security systems. The RSS consists of an independent sensor pod, a mobile sensor platform and a control and display console. Sensor data fusion is used to optimize the system's intrusion detection performance. These programs are complementary, the RSV concentrates on developing autonomous mobility, while the RSS thrust is on mobile sensor employment. 3 figs.« less

Effects of shade and feeding zilpaterol hydrochloride to finishing steers on performance, carcass quality, mobility, and body temperature

USDA-ARS?s Scientific Manuscript database

Crossbred steers (n=480) were utilized to study the effects of shade and feeding zilpaterol hydrochloride (ZH) on performance, carcass quality, mobility, and body temperature (BT). A randomized block design with a 2×2 factorial arrangement of treatments was conducted with four replicates per treatme...

Adaptive Behavior for Mobile Robots

NASA Technical Reports Server (NTRS)

Huntsberger, Terrance

2009-01-01

The term "System for Mobility and Access to Rough Terrain" (SMART) denotes a theoretical framework, a control architecture, and an algorithm that implements the framework and architecture, for enabling a land-mobile robot to adapt to changing conditions. SMART is intended to enable the robot to recognize adverse terrain conditions beyond its optimal operational envelope, and, in response, to intelligently reconfigure itself (e.g., adjust suspension heights or baseline distances between suspension points) or adapt its driving techniques (e.g., engage in a crabbing motion as a switchback technique for ascending steep terrain). Conceived for original application aboard Mars rovers and similar autonomous or semi-autonomous mobile robots used in exploration of remote planets, SMART could also be applied to autonomous terrestrial vehicles to be used for search, rescue, and/or exploration on rough terrain.

Diesel Technology: Steering and Suspension.

ERIC Educational Resources Information Center

Miller, Roger; Scarberry, Terry; Tesch, Carl; Kellum, Mary

Competency-based teacher and student materials on steering and suspension are provided for a diesel technology curriculum. Eleven units of instruction cover the following topics: chassis, tires, and wheels; steering; and suspension. The materials are based on the curriculum-alignment concept of first stating the objectives, then developing…

Sediment Sampling in Estuarine Mudflats with an Aerial-Ground Robotic Team

PubMed Central

Deusdado, Pedro; Guedes, Magno; Silva, André; Marques, Francisco; Pinto, Eduardo; Rodrigues, Paulo; Lourenço, André; Mendonça, Ricardo; Santana, Pedro; Corisco, José; Almeida, Susana Marta; Portugal, Luís; Caldeira, Raquel; Barata, José; Flores, Luis

2016-01-01

This paper presents a robotic team suited for bottom sediment sampling and retrieval in mudflats, targeting environmental monitoring tasks. The robotic team encompasses a four-wheel-steering ground vehicle, equipped with a drilling tool designed to be able to retain wet soil, and a multi-rotor aerial vehicle for dynamic aerial imagery acquisition. On-demand aerial imagery, properly fused on an aerial mosaic, is used by remote human operators for specifying the robotic mission and supervising its execution. This is crucial for the success of an environmental monitoring study, as often it depends on human expertise to ensure the statistical significance and accuracy of the sampling procedures. Although the literature is rich on environmental monitoring sampling procedures, in mudflats, there is a gap as regards including robotic elements. This paper closes this gap by also proposing a preliminary experimental protocol tailored to exploit the capabilities offered by the robotic system. Field trials in the south bank of the river Tagus’ estuary show the ability of the robotic system to successfully extract and transport bottom sediment samples for offline analysis. The results also show the efficiency of the extraction and the benefits when compared to (conventional) human-based sampling. PMID:27618060

Cross-coupled control for all-terrain rovers.

PubMed

Reina, Giulio

2013-01-08

Mobile robots are increasingly being used in challenging outdoor environments for applications that include construction, mining, agriculture, military and planetary exploration. In order to accomplish the planned task, it is critical that the motion control system ensure accuracy and robustness. The achievement of high performance on rough terrain is tightly connected with the minimization of vehicle-terrain dynamics effects such as slipping and skidding. This paper presents a cross-coupled controller for a 4-wheel-drive/4-wheel-steer robot, which optimizes the wheel motors' control algorithm to reduce synchronization errors that would otherwise result in wheel slip with conventional controllers. Experimental results, obtained with an all-terrain rover operating on agricultural terrain, are presented to validate the system. It is shown that the proposed approach is effective in reducing slippage and vehicle posture errors.

Extensible Hardware Architecture for Mobile Robots

NASA Technical Reports Server (NTRS)

Park, Eric; Kobayashi, Linda; Lee, Susan Y.

2005-01-01

The Intelligent Robotics Group at NASA Ames Research Center has developed a new mobile robot hardware architecture designed for extensibility and reconfigurability. Currently implemented on the k9 rover. and won to be integrated onto the K10 series of human-robot collaboration research robots, this architecture allows for rapid changes in instrumentation configuration and provides a high degree of modularity through a synergistic mix of off-the-shelf and custom designed components, allowing eased transplantation into a wide vane6 of mobile robot platforms. A component level overview of this architecture is presented along with a description of the changes required for implementation on K10 , followed by plans for future work.

Mobile robotics research at Sandia National Laboratories

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morse, W.D.

Sandia is a National Security Laboratory providing scientific and engineering solutions to meet national needs for both government and industry. As part of this mission, the Intelligent Systems and Robotics Center conducts research and development in robotics and intelligent machine technologies. An overview of Sandia`s mobile robotics research is provided. Recent achievements and future directions in the areas of coordinated mobile manipulation, small smart machines, world modeling, and special application robots are presented.

Robust dead reckoning system for mobile robots based on particle filter and raw range scan.

PubMed

Duan, Zhuohua; Cai, Zixing; Min, Huaqing

2014-09-04

Robust dead reckoning is a complicated problem for wheeled mobile robots (WMRs), where the robots are faulty, such as the sticking of sensors or the slippage of wheels, for the discrete fault models and the continuous states have to be estimated simultaneously to reach a reliable fault diagnosis and accurate dead reckoning. Particle filters are one of the most promising approaches to handle hybrid system estimation problems, and they have also been widely used in many WMRs applications, such as pose tracking, SLAM, video tracking, fault identification, etc. In this paper, the readings of a laser range finder, which may be also interfered with by noises, are used to reach accurate dead reckoning. The main contribution is that a systematic method to implement fault diagnosis and dead reckoning in a particle filter framework concurrently is proposed. Firstly, the perception model of a laser range finder is given, where the raw scan may be faulty. Secondly, the kinematics of the normal model and different fault models for WMRs are given. Thirdly, the particle filter for fault diagnosis and dead reckoning is discussed. At last, experiments and analyses are reported to show the accuracy and efficiency of the presented method.

Bioinspired Intelligent Algorithm and Its Applications for Mobile Robot Control: A Survey.

PubMed

Ni, Jianjun; Wu, Liuying; Fan, Xinnan; Yang, Simon X

2016-01-01

Bioinspired intelligent algorithm (BIA) is a kind of intelligent computing method, which is with a more lifelike biological working mechanism than other types. BIAs have made significant progress in both understanding of the neuroscience and biological systems and applying to various fields. Mobile robot control is one of the main application fields of BIAs which has attracted more and more attention, because mobile robots can be used widely and general artificial intelligent algorithms meet a development bottleneck in this field, such as complex computing and the dependence on high-precision sensors. This paper presents a survey of recent research in BIAs, which focuses on the research in the realization of various BIAs based on different working mechanisms and the applications for mobile robot control, to help in understanding BIAs comprehensively and clearly. The survey has four primary parts: a classification of BIAs from the biomimetic mechanism, a summary of several typical BIAs from different levels, an overview of current applications of BIAs in mobile robot control, and a description of some possible future directions for research.

Bioinspired Intelligent Algorithm and Its Applications for Mobile Robot Control: A Survey

PubMed Central

Ni, Jianjun; Wu, Liuying; Fan, Xinnan; Yang, Simon X.

2016-01-01

Bioinspired intelligent algorithm (BIA) is a kind of intelligent computing method, which is with a more lifelike biological working mechanism than other types. BIAs have made significant progress in both understanding of the neuroscience and biological systems and applying to various fields. Mobile robot control is one of the main application fields of BIAs which has attracted more and more attention, because mobile robots can be used widely and general artificial intelligent algorithms meet a development bottleneck in this field, such as complex computing and the dependence on high-precision sensors. This paper presents a survey of recent research in BIAs, which focuses on the research in the realization of various BIAs based on different working mechanisms and the applications for mobile robot control, to help in understanding BIAs comprehensively and clearly. The survey has four primary parts: a classification of BIAs from the biomimetic mechanism, a summary of several typical BIAs from different levels, an overview of current applications of BIAs in mobile robot control, and a description of some possible future directions for research. PMID:26819582

Modular Track System For Positioning Mobile Robots

NASA Technical Reports Server (NTRS)

Miller, Jeff

1995-01-01

Conceptual system for positioning mobile robotic manipulators on large main structure includes modular tracks and ancillary structures assembled easily along with main structure. System, called "tracked robotic location system" (TROLS), originally intended for application to platforms in outer space, but TROLS concept might also prove useful on Earth; for example, to position robots in factories and warehouses. T-cross-section rail keeps mobile robot on track. Bar codes mark locations along track. Each robot equipped with bar-code-recognizing circuitry so it quickly finds way to assigned location.

Human-Robot Interface: Issues in Operator Performance, Interface Design, and Technologies

DTIC Science & Technology

2006-07-01

and the use of lightweight portable robotic sensor platforms. 5 robotics has reached a point where some generalities of HRI transcend specific...displays with control devices such as joysticks, wheels, and pedals (Kamsickas, 2003). Typical control stations include panels displaying (a) sensor ...tasks that do not involve mobility and usually involve camera control or data fusion from sensors Active search: Search tasks that involve mobility

OCILOW-Wheeled Platform Controls Executable Set

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jansen, John F.

2005-11-30

The OCILOW Controls Executable Set is the complete set of machine executable instructions to control the motion of wheeled platforms that incorporate Off-Centered In-Line Omni-directional Wheels (OCILOW). The controls utilize command signals for the desired motion of the platform (X, Y and Theta) and calculate and control the steering and rolling motion required of each OCILOW wheels to achieve the desired translational and rotational platform motion. The controls utilize signals from the wheel steering and rolling resolvers, and from three load cells located at each wheels, to coordinate the motion of all wheels, while respecting their non-holonomic constraints (i.e., keepingmore » internal stresses and slippage due to possible errors, uneven floors, bumps, misalignment, etc. bounded). The OCILOW Controls Executable Set, which is copyrighted here, is an embodiment of the generic OCILOW algorithms (patented separately) developed specifically for controls of the Proof-of-Principle-Transporter (POP-T) system that has been developed to demonstrate the overall OCILOW controls feasibility and capabilities.« less

Design and performance tests of a distributed power-driven wheel loader

NASA Astrophysics Data System (ADS)

Jin, Xiaolin; Shi, Laide; Bian, Yongming

2010-03-01

An improved ZLM15B distributed power-driven wheel loader was designed, whose travel and brake system was accomplished by two permanent magnet synchronous motorized-wheels instead of traditional mechanical components, and whose hydraulic systems such as the working device system and steering system were both actuated by an induction motor. All above systems were flexibly coupled with 3-phase 380VAC electric power with which the diesel engine power is replaced. On the level cement road, traveling, braking, traction and steering tests were carried out separately under non-load and heavy-load conditions. Data show that machine speed is 5 km/h around and travel efficiency of motorized-wheels is above 95%; that machine braking deceleration is between 0.5 and 0.64 m/s2 but efficiency of motorized-wheels is less than 10%; that maximum machine traction is above 2t while efficiency of motorized-wheels is more than 90% and that adaptive differential steering can be smoothly achieved by motorized-wheels.

Design and performance tests of a distributed power-driven wheel loader

NASA Astrophysics Data System (ADS)

Jin, Xiaolin; Shi, Laide; Bian, Yongming

2009-12-01

An improved ZLM15B distributed power-driven wheel loader was designed, whose travel and brake system was accomplished by two permanent magnet synchronous motorized-wheels instead of traditional mechanical components, and whose hydraulic systems such as the working device system and steering system were both actuated by an induction motor. All above systems were flexibly coupled with 3-phase 380VAC electric power with which the diesel engine power is replaced. On the level cement road, traveling, braking, traction and steering tests were carried out separately under non-load and heavy-load conditions. Data show that machine speed is 5 km/h around and travel efficiency of motorized-wheels is above 95%; that machine braking deceleration is between 0.5 and 0.64 m/s2 but efficiency of motorized-wheels is less than 10%; that maximum machine traction is above 2t while efficiency of motorized-wheels is more than 90% and that adaptive differential steering can be smoothly achieved by motorized-wheels.

46 CFR 131.845 - Instructions for shift of steering gear.

Code of Federal Regulations, 2013 CFR

2013-10-01

... alternative steering stations must be on water-resistant material and posted at each steering station and in... gear or steering stations. (d) Each clutch, gear, wheel, lever, valve, or switch used during any shift of steering gear or steering stations must be numbered or lettered on a metal plate or painted so...

Meeting the challenges of installing a mobile robotic system

NASA Technical Reports Server (NTRS)

Decorte, Celeste

1994-01-01

The challenges of integrating a mobile robotic system into an application environment are many. Most problems inherent to installing the mobile robotic system fall into one of three categories: (1) the physical environment - location(s) where, and conditions under which, the mobile robotic system will work; (2) the technological environment - external equipment with which the mobile robotic system will interact; and (3) the human environment - personnel who will operate and interact with the mobile robotic system. The successful integration of a mobile robotic system into these three types of application environment requires more than a good pair of pliers. The tools for this job include: careful planning, accurate measurement data (as-built drawings), complete technical data of systems to be interfaced, sufficient time and attention of key personnel for training on how to operate and program the robot, on-site access during installation, and a thorough understanding and appreciation - by all concerned - of the mobile robotic system's role in the security mission at the site, as well as the machine's capabilities and limitations. Patience, luck, and a sense of humor are also useful tools to keep handy during a mobile robotic system installation. This paper will discuss some specific examples of problems in each of three categories, and explore approaches to solving these problems. The discussion will draw from the author's experience with on-site installations of mobile robotic systems in various applications. Most of the information discussed in this paper has come directly from knowledge learned during installations of Cybermotion's SR2 security robots. A large part of the discussion will apply to any vehicle with a drive system, collision avoidance, and navigation sensors, which is, of course, what makes a vehicle autonomous. And it is with these sensors and a drive system that the installer must become familiar in order to foresee potential trouble areas in the

A development of intelligent entertainment robot for home life

NASA Astrophysics Data System (ADS)

Kim, Cheoltaek; Lee, Ju-Jang

2005-12-01

The purpose of this paper was to present the study and design idea for entertainment robot with educational purpose (IRFEE). The robot has been designed for home life considering dependability and interaction. The developed robot has three objectives - 1. Develop autonomous robot, 2. Design robot considering mobility and robustness, 3. Develop robot interface and software considering entertainment and education functionalities. The autonomous navigation was implemented by active vision based SLAM and modified EPF algorithm. The two differential wheels, the pan-tilt were designed mobility and robustness and the exterior was designed considering esthetic element and minimizing interference. The speech and tracking algorithm provided the good interface with human. The image transfer and Internet site connection is needed for service of remote connection and educational purpose.

[Active and safe with wheeled walkers : Pilot study on feasibility of mobility exercises for wheeled walker users].

PubMed

Pflaum, Marina; Lang, Frieder R; Freiberger, Ellen

2016-07-01

The number of older people with mobility impairments using wheeled walkers is increasing; however, the handling of these walking aids is often ineffective. Moreover, age-associated functional loss, environmental demands and fear of falling may additionally challenge mobility. The new training program "Active and safe with wheeled walkers" aims to enhance skills and to improve mobility. The present pilot study was carried out to assess the feasibility of the training as well as to identify training effects and methodological insights for further research. The study was carried out with 28 wheeled walker users (age 68-91 years) in assisted living facilities using a pre-post design. Of the participants 13 persons were trained for 10 weeks (90 min, twice a week) and 15 persons served as a control group. Data were collected on functional mobility, hand strength, leg strength, balance, walker handling and fear of falling. The drop-out rate for the training was 38 % due to health concerns (n = 2), lack of time (n = 1) and changes in health status independent of training (n = 3). Medium to large effects were detected. Data regarding the recruitment strategy and the acceptance of individual exercises are available. The results indicate a good feasibility and effectiveness of the training. The simple accessibility of the training was conducive for the regular participation. The everyday relevance of the results and the lack of comparable interventions suggest that further research efforts be carried out. Recruitment strategies, training requirements and data collection methods need to be optimized.

JOMAR: Joint Operations with Mobile Autonomous Robots

DTIC Science & Technology

2015-12-21

AFRL-AFOSR-JP-TR-2015-0009 JOMAR: Joint Operations with Mobile Autonomous Robots Edwin Olson UNIVERSITY OF MICHIGAN Final Report 12/21/2015...SUBTITLE JOMAR: Joint Operations with Mobile Autonomous Robots 5a. CONTRACT NUMBER FA23861114024 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...14. ABSTRACT Under this grant, we formulated and implemented a variety of novel algorithms that address core problems in multi- robot systems. These

Mobile robot knowledge base

NASA Astrophysics Data System (ADS)

Heath Pastore, Tracy; Barnes, Mitchell; Hallman, Rory

2005-05-01

Robot technology is developing at a rapid rate for both commercial and Department of Defense (DOD) applications. As a result, the task of managing both technology and experience information is growing. In the not-to-distant past, tracking development efforts of robot platforms, subsystems and components was not too difficult, expensive, or time consuming. To do the same today is a significant undertaking. The Mobile Robot Knowledge Base (MRKB) provides the robotics community with a web-accessible, centralized resource for sharing information, experience, and technology to more efficiently and effectively meet the needs of the robot system user. The resource includes searchable information on robot components, subsystems, mission payloads, platforms, and DOD robotics programs. In addition, the MRKB website provides a forum for technology and information transfer within the DOD robotics community and an interface for the Robotic Systems Pool (RSP). The RSP manages a collection of small teleoperated and semi-autonomous robotic platforms, available for loan to DOD and other qualified entities. The objective is to put robots in the hands of users and use the test data and fielding experience to improve robot systems.

Cross-Coupled Control for All-Terrain Rovers

PubMed Central

Reina, Giulio

2013-01-01

Mobile robots are increasingly being used in challenging outdoor environments for applications that include construction, mining, agriculture, military and planetary exploration. In order to accomplish the planned task, it is critical that the motion control system ensure accuracy and robustness. The achievement of high performance on rough terrain is tightly connected with the minimization of vehicle-terrain dynamics effects such as slipping and skidding. This paper presents a cross-coupled controller for a 4-wheel-drive/4-wheel-steer robot, which optimizes the wheel motors' control algorithm to reduce synchronization errors that would otherwise result in wheel slip with conventional controllers. Experimental results, obtained with an all-terrain rover operating on agricultural terrain, are presented to validate the system. It is shown that the proposed approach is effective in reducing slippage and vehicle posture errors. PMID:23299625

Mobile robots IV; Proceedings of the Meeting, Philadelphia, PA, Nov. 6, 7, 1989

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolfe, W.J.; Chun, W.H.

1990-01-01

The present conference on mobile robot systems discusses high-speed machine perception based on passive sensing, wide-angle optical ranging, three-dimensional path planning for flying/crawling robots, navigation of autonomous mobile intelligence in an unstructured natural environment, mechanical models for the locomotion of a four-articulated-track robot, a rule-based command language for a semiautonomous Mars rover, and a computer model of the structured light vision system for a Mars rover. Also discussed are optical flow and three-dimensional information for navigation, feature-based reasoning trail detection, a symbolic neural-net production system for obstacle avoidance and navigation, intelligent path planning for robot navigation in an unknown environment,more » behaviors from a hierarchical control system, stereoscopic TV systems, the REACT language for autonomous robots, and a man-amplifying exoskeleton.« less

A two-class self-paced BCI to control a robot in four directions.

PubMed

Ron-Angevin, Ricardo; Velasco-Alvarez, Francisco; Sancha-Ros, Salvador; da Silva-Sauer, Leandro

2011-01-01

In this work, an electroencephalographic analysis-based, self-paced (asynchronous) brain-computer interface (BCI) is proposed to control a mobile robot using four different navigation commands: turn right, turn left, move forward and move back. In order to reduce the probability of misclassification, the BCI is to be controlled with only two mental tasks (relaxed state versus imagination of right hand movements), using an audio-cued interface. Four healthy subjects participated in the experiment. After two sessions controlling a simulated robot in a virtual environment (which allowed the user to become familiar with the interface), three subjects successfully moved the robot in a real environment. The obtained results show that the proposed interface enables control over the robot, even for subjects with low BCI performance. © 2011 IEEE

Examples of design and achievement of vision systems for mobile robotics applications

NASA Astrophysics Data System (ADS)

Bonnin, Patrick J.; Cabaret, Laurent; Raulet, Ludovic; Hugel, Vincent; Blazevic, Pierre; M'Sirdi, Nacer K.; Coiffet, Philippe

2000-10-01

Our goal is to design and to achieve a multiple purpose vision system for various robotics applications : wheeled robots (like cars for autonomous driving), legged robots (six, four (SONY's AIBO) legged robots, and humanoid), flying robots (to inspect bridges for example) in various conditions : indoor or outdoor. Considering that the constraints depend on the application, we propose an edge segmentation implemented either in software, or in hardware using CPLDs (ASICs or FPGAs could be used too). After discussing the criteria of our choice, we propose a chain of image processing operators constituting an edge segmentation. Although this chain is quite simple and very fast to perform, results appear satisfactory. We proposed a software implementation of it. Its temporal optimization is based on : its implementation under the pixel data flow programming model, the gathering of local processing when it is possible, the simplification of computations, and the use of fast access data structures. Then, we describe a first dedicated hardware implementation of the first part, which requires 9CPLS in this low cost version. It is technically possible, but more expensive, to implement these algorithms using only a signle FPGA.

TMAP - A Versatile Mobile Robot

NASA Astrophysics Data System (ADS)

Weiss, Joel A.; Simmons, Richard K.

1989-03-01

TMAP, the Teleoperated Mobile All-purpose Platform, provides the Army with a low cost, light weight, flexibly designed, modularly expandable platform for support of maneuver forces and light infantry units. The highly mobile, four wheel drive, diesel-hydraulic platform is controllable at distances of up to 4km from a portable operator control unit using either fiber optic or RF control links. The Martin Marietta TMAP system is based on a hierarchical task decomposition Real-time Control System architecture that readily supports interchange of mission packages and provides the capability for simple incorporation of supervisory control concepts leading to increased system autonomy and resulting force multiplication. TMAP has been designed to support a variety of missions including target designation, anti-armor, anti-air, countermine, and reconnaissance/surveillance. As a target designation system TMAP will provide the soldier with increased survivability and effectiveness by providing substantial combat standoff, and the firepower effectiveness of several manual designator operators. Force-on-force analysis of simulated TMAP engagements indicate that TMAP should provide significant force multiplication for the Army in Air-Land Battle 2000.

Efficient Symbolic Task Planning for Multiple Mobile Robots

DTIC Science & Technology

2016-12-13

Efficient Symbolic Task Planning for Multiple Mobile Robots Yuqian Jiang December 13, 2016 Abstract Symbolic task planning enables a robot to make...high-level deci- sions toward a complex goal by computing a sequence of actions with minimum expected costs. This thesis builds on a single- robot ...time complexity of optimal planning for multiple mobile robots . In this thesis we first investigate the performance of the state-of-the-art solvers of

Integrated chassis control for a three-axle electric bus with distributed driving motors and active rear steering system

NASA Astrophysics Data System (ADS)

Liu, Wei; He, Hongwen; Sun, Fengchun; Lv, Jiangyi

2017-05-01

This paper describes an integrated chassis control framework for a novel three-axle electric bus with active rear steering (ARS) axle and four motors at the middle and rear wheels. The proposed integrated framework consists of four parts: (1) an active speed limiting controller is designed for anti-body slip control and rollover prevention; (2) an ARS controller is designed for coordinating the tyre wear between the driving wheels; (3) an inter-axle torque distribution controller is designed for optimal torque distribution between the axles, considering anti-wheel slip and battery power limitations and (4) a data acquisition and estimation module for collecting the measured and estimated vehicle states. To verify the performances, a simulation platform is established in Trucksim software combined with Simulink. Three test cases are particularly designed to show the performances. The proposed algorithm is compared with a simple even control algorithm. The test results show satisfactory lateral stability and rollover prevention performances under severe steering conditions. The desired tyre wear coordinating performance is also realised, and the wheel slip ratios are restricted within stable region during intensive driving and emergency braking with complicated road conditions.

Mobile Robot and Mobile Manipulator Research Towards ASTM Standards Development.

PubMed

Bostelman, Roger; Hong, Tsai; Legowik, Steven

2016-01-01

Performance standards for industrial mobile robots and mobile manipulators (robot arms onboard mobile robots) have only recently begun development. Low cost and standardized measurement techniques are needed to characterize system performance, compare different systems, and to determine if recalibration is required. This paper discusses work at the National Institute of Standards and Technology (NIST) and within the ASTM Committee F45 on Driverless Automatic Guided Industrial Vehicles. This includes standards for both terminology, F45.91, and for navigation performance test methods, F45.02. The paper defines terms that are being considered. Additionally, the paper describes navigation test methods that are near ballot and docking test methods being designed for consideration within F45.02. This includes the use of low cost artifacts that can provide alternatives to using relatively expensive measurement systems.

Mamdani Fuzzy System for Indoor Autonomous Mobile Robot

NASA Astrophysics Data System (ADS)

Khan, M. K. A. Ahamed; Rashid, Razif; Elamvazuthi, I.

2011-06-01

Several control algorithms for autonomous mobile robot navigation have been proposed in the literature. Recently, the employment of non-analytical methods of computing such as fuzzy logic, evolutionary computation, and neural networks has demonstrated the utility and potential of these paradigms for intelligent control of mobile robot navigation. In this paper, Mamdani fuzzy system for an autonomous mobile robot is developed. The paper begins with the discussion on the conventional controller and then followed by the description of fuzzy logic controller in detail.

Robust Dead Reckoning System for Mobile Robots Based on Particle Filter and Raw Range Scan

PubMed Central

Duan, Zhuohua; Cai, Zixing; Min, Huaqing

2014-01-01

Robust dead reckoning is a complicated problem for wheeled mobile robots (WMRs), where the robots are faulty, such as the sticking of sensors or the slippage of wheels, for the discrete fault models and the continuous states have to be estimated simultaneously to reach a reliable fault diagnosis and accurate dead reckoning. Particle filters are one of the most promising approaches to handle hybrid system estimation problems, and they have also been widely used in many WMRs applications, such as pose tracking, SLAM, video tracking, fault identification, etc. In this paper, the readings of a laser range finder, which may be also interfered with by noises, are used to reach accurate dead reckoning. The main contribution is that a systematic method to implement fault diagnosis and dead reckoning in a particle filter framework concurrently is proposed. Firstly, the perception model of a laser range finder is given, where the raw scan may be faulty. Secondly, the kinematics of the normal model and different fault models for WMRs are given. Thirdly, the particle filter for fault diagnosis and dead reckoning is discussed. At last, experiments and analyses are reported to show the accuracy and efficiency of the presented method. PMID:25192318

GOAT (goes over all terrain) vehicle: a scaleable robotic vehicle

NASA Astrophysics Data System (ADS)

Dodson, Michael G.; Owsley, Stanley L.; Moorehead, Stewart J.

2003-09-01

Many of the potential applications of mobile robots require a small to medium sized vehicle that is capable of traversing large obstacles and rugged terrain. Search and rescue operations require a robot small enough to drive through doorways, yet capable enough to surmount rubble piles and stairs. This paper presents the GOAT (Goes Over All Terrain) vehicle, a medium scale robot which incorporates a novel configuration which puts the drive wheels on the ends of actuated arms. This allows GOAT to adjust body height and posture and combines the benefits of legged locomotion with the ease of wheeled driving. The paper presents the design of the GOAT and the results of prototype construction and initial testing.

Opportunity Rolls Free Again (Four Wheels)

NASA Technical Reports Server (NTRS)

2006-01-01

This animated piece illustrates the recent escape of NASA's Mars Exploration Rover Opportunity from dangerous, loose material on the vast plains leading to the rover's next long-term target, 'Victoria Crater.'

A series of images from the front and rear hazard-avoidance cameras make up this brief movie chronicling the challenge Opportunity faced to free itself from the ripple dubbed 'Jammerbugt.' Each quadrant shows one of the rover's four corner wheels: left front wheel in upper left, right front wheel in upper right, rear wheels in the lower quadrants. The wheels became partially embedded in the ripple at the end of a drive on Opportunity's 833rd Martian day, or sol (May 28, 2006). The images in this clip were taken on sols 836 through 841 (May 31 through June 5, 2006).

Scientists and engineers who had been elated at the meters of progress the rover had been making in earlier drives were happy for even centimeters of advance per sol as they maneuvered their explorer through the slippery material of Jammerbugt. The wheels reached solid footing on a rock outcrop on the final sol of this sequence.

The science and engineering teams appropriately chose the ripple's informal from name the name of a bay on the north coast of Denmark. Jammerbugt, or Jammerbugten, loosely translated, means Bay of Lamentation or Bay of Wailing. The shipping route from the North Sea to the Baltic passes Jammerbugt on its way around the northern tip of Jutland. This has always been an important trade route and many ships still pass by the bay. The prevailing wind directions are typically northwest to southwest with the strongest winds and storms tending to blow from the northwest. A northwesterly wind will blow straight into the Jammerbugt, towards shore. Therefore, in the age of sail, many ships sank there during storms. The shore is sandy, but can have strong waves, so running aground was very dangerous even though there are no rocks.

Fortunately, Opportunity

Autonomous undulatory serpentine locomotion utilizing body dynamics of a fluidic soft robot.

PubMed

Onal, Cagdas D; Rus, Daniela

2013-06-01

Soft robotics offers the unique promise of creating inherently safe and adaptive systems. These systems bring man-made machines closer to the natural capabilities of biological systems. An important requirement to enable self-contained soft mobile robots is an on-board power source. In this paper, we present an approach to create a bio-inspired soft robotic snake that can undulate in a similar way to its biological counterpart using pressure for actuation power, without human intervention. With this approach, we develop an autonomous soft snake robot with on-board actuation, power, computation and control capabilities. The robot consists of four bidirectional fluidic elastomer actuators in series to create a traveling curvature wave from head to tail along its body. Passive wheels between segments generate the necessary frictional anisotropy for forward locomotion. It takes 14 h to build the soft robotic snake, which can attain an average locomotion speed of 19 mm s(-1).

Unified Approach To Control Of Motions Of Mobile Robots

NASA Technical Reports Server (NTRS)

Seraji, Homayoun

1995-01-01

Improved computationally efficient scheme developed for on-line coordinated control of both manipulation and mobility of robots that include manipulator arms mounted on mobile bases. Present scheme similar to one described in "Coordinated Control of Mobile Robotic Manipulators" (NPO-19109). Both schemes based on configuration-control formalism. Present one incorporates explicit distinction between holonomic and nonholonomic constraints. Several other prior articles in NASA Tech Briefs discussed aspects of configuration-control formalism. These include "Increasing the Dexterity of Redundant Robots" (NPO-17801), "Redundant Robot Can Avoid Obstacles" (NPO-17852), "Configuration-Control Scheme Copes with Singularities" (NPO-18556), "More Uses for Configuration Control of Robots" (NPO-18607/NPO-18608).

Mobile Robot and Mobile Manipulator Research Towards ASTM Standards Development

PubMed Central

Bostelman, Roger; Hong, Tsai; Legowik, Steven

2017-01-01

Performance standards for industrial mobile robots and mobile manipulators (robot arms onboard mobile robots) have only recently begun development. Low cost and standardized measurement techniques are needed to characterize system performance, compare different systems, and to determine if recalibration is required. This paper discusses work at the National Institute of Standards and Technology (NIST) and within the ASTM Committee F45 on Driverless Automatic Guided Industrial Vehicles. This includes standards for both terminology, F45.91, and for navigation performance test methods, F45.02. The paper defines terms that are being considered. Additionally, the paper describes navigation test methods that are near ballot and docking test methods being designed for consideration within F45.02. This includes the use of low cost artifacts that can provide alternatives to using relatively expensive measurement systems. PMID:28690359

Modeling of Driver Steering Operations in Lateral Wind Disturbances toward Driver Assistance System

NASA Astrophysics Data System (ADS)

Kurata, Yoshinori; Wada, Takahiro; Kamiji, Norimasa; Doi, Shun'ichi

Disturbances decrease vehicle stability and increase driver's mental and physical workload. Especially unexpected disturbances such as lateral winds have severe effect on vehicle stability and driver's workload. This study aims at building a driver model of steering operations in lateral wind toward developing effective driver assistance system. First, the relationship between the driver's lateral motion and its reactive quick steering behavior is investigated using driving simulator with lateral 1dof motion. In the experiments, four different wind patterns are displayed by the simulator. As the results, strong correlation was found between the driver's head lateral jerk by the lateral disturbance and the angular acceleration of the steering wheel. Then, we build a mathematical model of driver's steering model from lateral disturbance input to steering torque of the reactive quick feed-forward steering based on the experimental results. Finally, validity of the proposed model is shown by comparing the steering torque of experimental results and that of simulation results.

Mobility-Dependent Motion Planning for High Speed Robotic Vehicles

DTIC Science & Technology

2008-07-25

of the vehicle’s mobility in such type of terrain. Moreover, autonomous driv- ing of wheeled vehicles at high speeds adds a new level of complexity due...dynamic effects such as wheel slip, skidding, ballistic behavior, rollover, and vehicle-terrain interaction phenomena. Navigation algorithms must also...description of mobility was defined as the probability that for a given 6 ini ial v 10 ity at an initial po ition h robo will hav a non-n gative ve- loci y

Hierarchical Modelling Of Mobile, Seeing Robots

NASA Astrophysics Data System (ADS)

Luh, Cheng-Jye; Zeigler, Bernard P.

1990-03-01

This paper describes the implementation of a hierarchical robot simulation which supports the design of robots with vision and mobility. A seeing robot applies a classification expert system for visual identification of laboratory objects. The visual data acquisition algorithm used by the robot vision system has been developed to exploit multiple viewing distances and perspectives. Several different simulations have been run testing the visual logic in a laboratory environment. Much work remains to integrate the vision system with the rest of the robot system.

Hierarchical modelling of mobile, seeing robots

NASA Technical Reports Server (NTRS)

Luh, Cheng-Jye; Zeigler, Bernard P.

1990-01-01

This paper describes the implementation of a hierarchical robot simulation which supports the design of robots with vision and mobility. A seeing robot applies a classification expert system for visual identification of laboratory objects. The visual data acquisition algorithm used by the robot vision system has been developed to exploit multiple viewing distances and perspectives. Several different simulations have been run testing the visual logic in a laboratory environment. Much work remains to integrate the vision system with the rest of the robot system.

Speed control for a mobile robot

NASA Astrophysics Data System (ADS)

Kolli, Kaylan C.; Mallikarjun, Sreeram; Kola, Krishnamohan; Hall, Ernest L.

1997-09-01

Automated guided vehicles (AGVs) have many potential applications in manufacturing, medicine, space and defense. The purpose of this paper is to describe exploratory research on the design of a speed control for a modular autonomous mobile robot controller. The speed control of the traction motor is essential for safe operation of a mobile robot. The challenges of autonomous operation of a vehicle require safe, runaway and collision free operation. A mobile robot test-bed has been constructed using a golf cart base. The computer controlled speed control has been implemented and works with guidance provided by vision system and obstacle avoidance using ultrasonic sensors systems. A 486 computer through a 3- axis motion controller supervises the speed control. The traction motor is controlled via the computer by an EV-1 speed control. Testing of the system was done both in the lab and on an outside course with positive results. This design is a prototype and suggestions for improvements are also given. The autonomous speed controller is applicable for any computer controlled electric drive mobile vehicle.

Control performance of a road vehicle with four independent single-wheel electric motors and steer-by-wire system

NASA Astrophysics Data System (ADS)

Weiskircher, Thomas; Müller, Steffen

2012-01-01

This article presents a motion controller for a road vehicle equipped with a steer-by-wire system and four independent electric rim-mounted drives. The motion controller separates the control law from the specific actuator setup by the usage of virtual global control variables acting on the vehicle centre of gravity. A control allocation algorithm distributes the virtual control variables to the available actuators. An approximation of the real actuator dynamics is used to analyse the performance of different motion controller types in the linear and nonlinear driving regions. In addition, a vehicle state observer consisting of a traction force observer and an unscented Kalman filter is discussed to analyse the control behaviour in the case of a real sensor setup.

Development and validation of a low-cost mobile robotics testbed

NASA Astrophysics Data System (ADS)

Johnson, Michael; Hayes, Martin J.

2012-03-01

This paper considers the design, construction and validation of a low-cost experimental robotic testbed, which allows for the localisation and tracking of multiple robotic agents in real time. The testbed system is suitable for research and education in a range of different mobile robotic applications, for validating theoretical as well as practical research work in the field of digital control, mobile robotics, graphical programming and video tracking systems. It provides a reconfigurable floor space for mobile robotic agents to operate within, while tracking the position of multiple agents in real-time using the overhead vision system. The overall system provides a highly cost-effective solution to the topical problem of providing students with practical robotics experience within severe budget constraints. Several problems encountered in the design and development of the mobile robotic testbed and associated tracking system, such as radial lens distortion and the selection of robot identifier templates are clearly addressed. The testbed performance is quantified and several experiments involving LEGO Mindstorm NXT and Merlin System MiaBot robots are discussed.

ANYmal - A Highly Mobile and Dynamic Quadrupedal Robot

DTIC Science & Technology

2016-10-09

ANYmal - A Highly Mobile and Dynamic Quadrupedal Robot * Marco Hutter1, Christian Gehring2, Dominic Jud1, Andreas Lauber1, C. Dario Bellicoso1...Abstract— This paper introduces ANYmal, a quadrupedal robot that features outstanding mobility and dynamic motion capability. Thanks to novel...compliant joint modules with integrated electronics, the 30 kg, 0.5 m tall robotic dog is torque controllable and very robust against impulsive loads during

Evaluation of a Home Biomonitoring Autonomous Mobile Robot.

PubMed

Dorronzoro Zubiete, Enrique; Nakahata, Keigo; Imamoglu, Nevrez; Sekine, Masashi; Sun, Guanghao; Gomez, Isabel; Yu, Wenwei

2016-01-01

Increasing population age demands more services in healthcare domain. It has been shown that mobile robots could be a potential solution to home biomonitoring for the elderly. Through our previous studies, a mobile robot system that is able to track a subject and identify his daily living activities has been developed. However, the system has not been tested in any home living scenarios. In this study we did a series of experiments to investigate the accuracy of activity recognition of the mobile robot in a home living scenario. The daily activities tested in the evaluation experiment include watching TV and sleeping. A dataset recorded by a distributed distance-measuring sensor network was used as a reference to the activity recognition results. It was shown that the accuracy is not consistent for all the activities; that is, mobile robot could achieve a high success rate in some activities but a poor success rate in others. It was found that the observation position of the mobile robot and subject surroundings have high impact on the accuracy of the activity recognition, due to the variability of the home living daily activities and their transitional process. The possibility of improvement of recognition accuracy has been shown too.

Followup Audit: DLA Officials Took Appropriate Actions to Address Concerns With Repair Parts for the High Mobility Multipurpose Wheeled Vehicle

DTIC Science & Technology

2016-04-29

Followup Audit : DLA Officials Took Appropriate Actions to Address Concerns With Repair Parts for the High Mobility Multipurpose Wheeled Vehicle A P R I L...Results in Brief Followup Audit : DLA Officials Took Appropriate Actions to Address Concerns With Repair Parts for the High Mobility Multipurpose Wheeled...and Maritime Paid Too Much for High Mobility Multipurpose Wheeled Vehicle Repair Parts,” (HMMWV) was issued on April 4, 2014. The audit

Homography-based visual servo regulation of mobile robots.

PubMed

Fang, Yongchun; Dixon, Warren E; Dawson, Darren M; Chawda, Prakash

2005-10-01

A monocular camera-based vision system attached to a mobile robot (i.e., the camera-in-hand configuration) is considered in this paper. By comparing corresponding target points of an object from two different camera images, geometric relationships are exploited to derive a transformation that relates the actual position and orientation of the mobile robot to a reference position and orientation. This transformation is used to synthesize a rotation and translation error system from the current position and orientation to the fixed reference position and orientation. Lyapunov-based techniques are used to construct an adaptive estimate to compensate for a constant, unmeasurable depth parameter, and to prove asymptotic regulation of the mobile robot. The contribution of this paper is that Lyapunov techniques are exploited to craft an adaptive controller that enables mobile robot position and orientation regulation despite the lack of an object model and the lack of depth information. Experimental results are provided to illustrate the performance of the controller.

Directional control-response compatibility of joystick steered shuttle cars.

PubMed

Burgess-Limerick, Robin; Zupanc, Christine M; Wallis, Guy

2012-01-01

Shuttle cars are an unusual class of vehicle operated in underground coal mines, sometimes in close proximity to pedestrians and steering errors may have very serious consequences. A directional control-response incompatibility has previously been described in shuttle cars which are controlled using a steering wheel oriented perpendicular to the direction of travel. Some other shuttle car operators are seated perpendicular to the direction of travel and steer the car via a seat mounted joystick. A virtual simulation was utilised to determine whether the steering arrangement in these vehicles maintains directional control-response compatibility. Twenty-four participants were randomly assigned to either a condition corresponding to this design (consistent direction), or a condition in which the directional steering response was reversed while driving in-bye (visual field compatible). Significantly less accurate steering performance was exhibited by the consistent direction group during the in-bye trials only. Shuttle cars which provide the joystick steering mechanism described here require operators to accommodate alternating compatible and incompatible directional control-response relationships with each change of car direction. A virtual simulation of an underground coal shuttle car demonstrates that the design incorporates a directional control-response incompatibility when driving the vehicle in one direction. This design increases the probability of operator error, with potential adverse safety and productivity consequences.

Lunar surface exploration using mobile robots

NASA Astrophysics Data System (ADS)

Nishida, Shin-Ichiro; Wakabayashi, Sachiko

2012-06-01

A lunar exploration architecture study is being carried out by space agencies. JAXA is carrying out research and development of a mobile robot (rover) to be deployed on the lunar surface for exploration and outpost construction. The main target areas for outpost construction and lunar exploration are mountainous zones. The moon's surface is covered by regolith. Achieving a steady traversal of such irregular terrain constitutes the major technical problem for rovers. A newly developed lightweight crawler mechanism can effectively traverse such irregular terrain because of its low contact force with the ground. This fact was determined on the basis of the mass and expected payload of the rover. This paper describes a plan for Japanese lunar surface exploration using mobile robots, and presents the results of testing and analysis needed in their development. This paper also gives an overview of the lunar exploration robot to be deployed in the SELENE follow-on mission, and the composition of its mobility, navigation, and control systems.

Robotic vehicle with multiple tracked mobility platforms

DOEpatents

Salton, Jonathan R [Albuquerque, NM; Buttz, James H [Albuquerque, NM; Garretson, Justin [Albuquerque, NM; Hayward, David R [Wetmore, CO; Hobart, Clinton G [Albuquerque, NM; Deuel, Jr., Jamieson K.

2012-07-24

A robotic vehicle having two or more tracked mobility platforms that are mechanically linked together with a two-dimensional coupling, thereby forming a composite vehicle of increased mobility. The robotic vehicle is operative in hazardous environments and can be capable of semi-submersible operation. The robotic vehicle is capable of remote controlled operation via radio frequency and/or fiber optic communication link to a remote operator control unit. The tracks have a plurality of track-edge scallop cut-outs that allow the tracks to easily grab onto and roll across railroad tracks, especially when crossing the railroad tracks at an oblique angle.

Localization Based on Magnetic Markers for an All-Wheel Steering Vehicle

PubMed Central

Byun, Yeun Sub; Kim, Young Chol

2016-01-01

Real-time continuous localization is a key technology in the development of intelligent transportation systems. In these systems, it is very important to have accurate information about the position and heading angle of the vehicle at all times. The most widely implemented methods for positioning are the global positioning system (GPS), vision-based system, and magnetic marker system. Among these methods, the magnetic marker system is less vulnerable to indoor and outdoor environment conditions; moreover, it requires minimal maintenance expenses. In this paper, we present a position estimation scheme based on magnetic markers and odometry sensors for an all-wheel-steering vehicle. The heading angle of the vehicle is determined by using the position coordinates of the last two detected magnetic markers and odometer data. The instant position and heading angle of the vehicle are integrated with an extended Kalman filter to estimate the continuous position. GPS data with the real-time kinematics mode was obtained to evaluate the performance of the proposed position estimation system. The test results show that the performance of the proposed localization algorithm is accurate (mean error: 3 cm; max error: 9 cm) and reliable under unexpected missing markers or incorrect markers. PMID:27916827

Mobile robot motion estimation using Hough transform

NASA Astrophysics Data System (ADS)

Aldoshkin, D. N.; Yamskikh, T. N.; Tsarev, R. Yu

2018-05-01

This paper proposes an algorithm for estimation of mobile robot motion. The geometry of surrounding space is described with range scans (samples of distance measurements) taken by the mobile robot’s range sensors. A similar sample of space geometry in any arbitrary preceding moment of time or the environment map can be used as a reference. The suggested algorithm is invariant to isotropic scaling of samples or map that allows using samples measured in different units and maps made at different scales. The algorithm is based on Hough transform: it maps from measurement space to a straight-line parameters space. In the straight-line parameters, space the problems of estimating rotation, scaling and translation are solved separately breaking down a problem of estimating mobile robot localization into three smaller independent problems. The specific feature of the algorithm presented is its robustness to noise and outliers inherited from Hough transform. The prototype of the system of mobile robot orientation is described.

Autonomous Mobile Platform for Research in Cooperative Robotics

NASA Technical Reports Server (NTRS)

Daemi, Ali; Pena, Edward; Ferguson, Paul

1998-01-01

This paper describes the design and development of a platform for research in cooperative mobile robotics. The structure and mechanics of the vehicles are based on R/C cars. The vehicle is rendered mobile by a DC motor and servo motor. The perception of the robot's environment is achieved using IR sensors and a central vision system. A laptop computer processes images from a CCD camera located above the testing area to determine the position of objects in sight. This information is sent to each robot via RF modem. Each robot is operated by a Motorola 68HC11E micro-controller, and all actions of the robots are realized through the connections of IR sensors, modem, and motors. The intelligent behavior of each robot is based on a hierarchical fuzzy-rule based approach.

Injuries to Occupants of U.S. Army High Mobility Multipurpose Wheeled Vehicles in Rollover Accidents, 1989-2007

DTIC Science & Technology

2013-04-02

This research conducted on occupant injuries in U.S. Army High Mobility Multipurpose Wheeled Vehicle (HMMWV) rollover accidents was presented at the ...12  1 Introduction The High Mobility Multipurpose Wheeled Vehicle (HMMWV) is...Soldiers may experience the full impact of jarring forces and/or projectile forces of unrestrained equipment. Rollovers are especially hazardous to

Robust performance of multiple tasks by a mobile robot

NASA Technical Reports Server (NTRS)

Beckerman, Martin; Barnett, Deanna L.; Dickens, Mike; Weisbin, Charles R.

1989-01-01

While there have been many successful mobile robot experiments, only a few papers have addressed issues pertaining to the range of applicability, or robustness, of robotic systems. The purpose of this paper is to report results of a series of benchmark experiments done to determine and quantify the robustness of an integrated hardware and software system of a mobile robot.

A locust-inspired miniature jumping robot.

PubMed

Zaitsev, Valentin; Gvirsman, Omer; Ben Hanan, Uri; Weiss, Avi; Ayali, Amir; Kosa, Gabor

2015-11-25

Unmanned ground vehicles are mostly wheeled, tracked, or legged. These locomotion mechanisms have a limited ability to traverse rough terrain and obstacles that are higher than the robot's center of mass. In order to improve the mobility of small robots it is necessary to expand the variety of their motion gaits. Jumping is one of nature's solutions to the challenge of mobility in difficult terrain. The desert locust is the model for the presented bio-inspired design of a jumping mechanism for a small mobile robot. The basic mechanism is similar to that of the semilunar process in the hind legs of the locust, and is based on the cocking of a torsional spring by wrapping a tendon-like wire around the shaft of a miniature motor. In this study we present the jumping mechanism design, and the manufacturing and performance analysis of two demonstrator prototypes. The most advanced jumping robot demonstrator is power autonomous, weighs 23 gr, and is capable of jumping to a height of 3.35 m, covering a distance of 1.37 m.

Certainty grids for mobile robots

NASA Technical Reports Server (NTRS)

Moravec, H. P.

1987-01-01

A numerical representation of uncertain and incomplete sensor knowledge called Certainty Grids has been used successfully in several mobile robot control programs, and has proven itself to be a powerful and efficient unifying solution for sensor fusion, motion planning, landmark identification, and many other central problems. Researchers propose to build a software framework running on processors onboard the new Uranus mobile robot that will maintain a probabilistic, geometric map of the robot's surroundings as it moves. The certainty grid representation will allow this map to be incrementally updated in a uniform way from various sources including sonar, stereo vision, proximity and contact sensors. The approach can correctly model the fuzziness of each reading, while at the same time combining multiple measurements to produce sharper map features, and it can deal correctly with uncertainties in the robot's motion. The map will be used by planning programs to choose clear paths, identify locations (by correlating maps), identify well-known and insufficiently sensed terrain, and perhaps identify objects by shape. The certainty grid representation can be extended in the same dimension and used to detect and track moving objects.

46 CFR 97.37-33 - Instructions for changing steering gear.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Instructions for changing steering gear. 97.37-33... steering gear. (a) Instructions in at least 1/2 inch letters and figures shall be posted in the steering... gear. Each clutch, gear, wheel, lever, valve, or switch which is used during the changeover shall be...

Robot navigation research using the HERMIES mobile robot

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barnett, D.L.

1989-01-01

In recent years robot navigation has attracted much attention from researchers around the world. Not only are theoretical studies being simulated on sophisticated computers, but many mobile robots are now used as test vehicles for these theoretical studies. Various algorithms have been perfected for navigation in a known static environment; but navigation in an unknown and dynamic environment poses a much more challenging problem for researchers. Many different methodologies have been developed for autonomous robot navigation, but each methodology is usually restricted to a particular type of environment. One important research focus of the Center for Engineering Systems Advanced researchmore » (CESAR) at Oak Ridge National Laboratory, is autonomous navigation in unknown and dynamic environments using the series of HERMIES mobile robots. The research uses an expert system for high-level planning interfaced with C-coded routines for implementing the plans, and for quick processing of data requested by the expert system. In using this approach, the navigation is not restricted to one methodology since the expert system can activate a rule module for the methodology best suited for the current situation. Rule modules can be added the rule base as they are developed and tested. Modules are being developed or enhanced for navigating from a map, searching for a target, exploring, artificial potential-field navigation, navigation using edge-detection, etc. This paper will report on the various rule modules and methods of navigation in use, or under development at CESAR, using the HERMIES-IIB robot as a testbed. 13 refs., 5 figs., 1 tab.« less

Constrained motion model of mobile robots and its applications.

PubMed

Zhang, Fei; Xi, Yugeng; Lin, Zongli; Chen, Weidong

2009-06-01

Target detecting and dynamic coverage are fundamental tasks in mobile robotics and represent two important features of mobile robots: mobility and perceptivity. This paper establishes the constrained motion model and sensor model of a mobile robot to represent these two features and defines the k -step reachable region to describe the states that the robot may reach. We show that the calculation of the k-step reachable region can be reduced from that of 2(k) reachable regions with the fixed motion styles to k + 1 such regions and provide an algorithm for its calculation. Based on the constrained motion model and the k -step reachable region, the problems associated with target detecting and dynamic coverage are formulated and solved. For target detecting, the k-step detectable region is used to describe the area that the robot may detect, and an algorithm for detecting a target and planning the optimal path is proposed. For dynamic coverage, the k-step detected region is used to represent the area that the robot has detected during its motion, and the dynamic-coverage strategy and algorithm are proposed. Simulation results demonstrate the efficiency of the coverage algorithm in both convex and concave environments.

Towards Principled Experimental Study of Autonomous Mobile Robots

NASA Technical Reports Server (NTRS)

Gat, Erann

1995-01-01

We review the current state of research in autonomous mobile robots and conclude that there is an inadequate basis for predicting the reliability and behavior of robots operating in unengineered environments. We present a new approach to the study of autonomous mobile robot performance based on formal statistical analysis of independently reproducible experiments conducted on real robots. Simulators serve as models rather than experimental surrogates. We demonstrate three new results: 1) Two commonly used performance metrics (time and distance) are not as well correlated as is often tacitly assumed. 2) The probability distributions of these performance metrics are exponential rather than normal, and 3) a modular, object-oriented simulation accurately predicts the behavior of the real robot in a statistically significant manner.

Static load simulation of steering knuckle for a formula student race car

NASA Astrophysics Data System (ADS)

Saputro, Bagus Aulia; Ubaidillah, Triono, Dicky Agus; Pratama, Dzaky Roja; Cahyono, Sukmaji Indro; Imaduddin, Fitrian

2018-02-01

This research aims to determine the stress distribution which occurs on the steering knuckle and to define its safety factor number. Steering knuckle is the most critical part of a car's steering system. Steering knuckle supports the tie rod, brake caliper, and the wheels to provide stability. Steering knuckle withstands the load which given on the front wheels and functions as the wheel's axis. Balljoint and king support the rotation of the suspension arm. When the car is in idle position, knuckle hold the weight of the car, it gets braking force when it's braking and cornering. Knuckle is designed to have the strength that could withstand load and to have a good safety factor value. Knuckle is designed using Fusion software then simulated using Fusion simulation software with a static load, moment braking force, and cornering force as the loads in this simulation. The simulation works in ideal condition. The result of this simulation is satisfying. This simulation produces a maximum displacement of 0.01281mm, the maximum shear stress is 3.707 MPa on the stub hole, and the safety factor is 5.24. The material used for this product is mild steel AISI 1018.

Intelligent robots for planetary exploration and construction

NASA Technical Reports Server (NTRS)

Albus, James S.

1992-01-01

Robots capable of practical applications in planetary exploration and construction will require realtime sensory-interactive goal-directed control systems. A reference model architecture based on the NIST Real-time Control System (RCS) for real-time intelligent control systems is suggested. RCS partitions the control problem into four basic elements: behavior generation (or task decomposition), world modeling, sensory processing, and value judgment. It clusters these elements into computational nodes that have responsibility for specific subsystems, and arranges these nodes in hierarchical layers such that each layer has characteristic functionality and timing. Planetary exploration robots should have mobility systems that can safely maneuver over rough surfaces at high speeds. Walking machines and wheeled vehicles with dynamic suspensions are candidates. The technology of sensing and sensory processing has progressed to the point where real-time autonomous path planning and obstacle avoidance behavior is feasible. Map-based navigation systems will support long-range mobility goals and plans. Planetary construction robots must have high strength-to-weight ratios for lifting and positioning tools and materials in six degrees-of-freedom over large working volumes. A new generation of cable-suspended Stewart platform devices and inflatable structures are suggested for lifting and positioning materials and structures, as well as for excavation, grading, and manipulating a variety of tools and construction machinery.

Remote-controlled vision-guided mobile robot system

NASA Astrophysics Data System (ADS)

Ande, Raymond; Samu, Tayib; Hall, Ernest L.

1997-09-01

Automated guided vehicles (AGVs) have many potential applications in manufacturing, medicine, space and defense. The purpose of this paper is to describe exploratory research on the design of the remote controlled emergency stop and vision systems for an autonomous mobile robot. The remote control provides human supervision and emergency stop capabilities for the autonomous vehicle. The vision guidance provides automatic operation. A mobile robot test-bed has been constructed using a golf cart base. The mobile robot (Bearcat) was built for the Association for Unmanned Vehicle Systems (AUVS) 1997 competition. The mobile robot has full speed control with guidance provided by a vision system and an obstacle avoidance system using ultrasonic sensors systems. Vision guidance is accomplished using two CCD cameras with zoom lenses. The vision data is processed by a high speed tracking device, communicating with the computer the X, Y coordinates of blobs along the lane markers. The system also has three emergency stop switches and a remote controlled emergency stop switch that can disable the traction motor and set the brake. Testing of these systems has been done in the lab as well as on an outside test track with positive results that show that at five mph the vehicle can follow a line and at the same time avoid obstacles.

Mobile robotics application in the nuclear industry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, S.L.; White, J.R.

1995-03-01

Mobile robots have been developed to perform hazardous operations in place of human workers. Applications include nuclear plant inspection/maintenance, decontamination and decommissioning police/military explosive ordinance disposal (EOD), hostage/terrorist negotiations and fire fighting. Nuclear facilities have proven that robotic applications can be cost-effective solutions to reducing personnel exposure and plant downtime. The first applications of mobile robots in the nuclear industry began in the early 1980`s, with the first vehicles being one of a kind machines or adaptations of commercial EOD robots. These activities included efforts by numerous commercial companies, the U.S. Nuclear Regulatory Commission, EPRI, and several national laboratories. Somemore » of these efforts were driven by the recovery and cleanup activities at TMI which demonstrated the potential and need for a remote means of performing surveillance and maintenance tasks in nuclear plants. The use of these machines is now becoming commonplace in nuclear facilities throughout the world. The hardware maturity and the confidence of the users has progressed to the point where the applications of mobile robots is not longer considered a novelty. These machines are being used in applications where the result is to help achieve more aggressive goals for personnel radiation exposure and plant availability, perform tasks more efficiently, and allow plant operators to retrieve information from areas previously considered inaccessible. Typical examples include surveillance in high radiation areas (during operation and outage activities), radiation surveys, waste handling, and decontamination evolutions. This paper will discuss this evolution including specific applications experiences, examples of currently available technology, and the benefits derived from the use of mobile robotic vehicles in commercial nuclear power facilities.« less

Embodied Computation: An Active-Learning Approach to Mobile Robotics Education

ERIC Educational Resources Information Center

Riek, L. D.

2013-01-01

This paper describes a newly designed upper-level undergraduate and graduate course, Autonomous Mobile Robots. The course employs active, cooperative, problem-based learning and is grounded in the fundamental computational problems in mobile robotics defined by Dudek and Jenkin. Students receive a broad survey of robotics through lectures, weekly…

Analytic and simulation studies on the use of torque-wheel actuators for the control of flexible robotic arms

NASA Technical Reports Server (NTRS)

Montgomery, Raymond C.; Ghosh, Dave; Kenny, Sean

1991-01-01

This paper presents results of analytic and simulation studies to determine the effectiveness of torque-wheel actuators in suppressing the vibrations of two-link telerobotic arms with attached payloads. The simulations use a planar generic model of a two-link arm with a torque wheel at the free end. Parameters of the arm model are selected to be representative of a large space-based robotic arm of the same class as the Space Shuttle Remote Manipulator, whereas parameters of the torque wheel are selected to be similar to those of the Mini-Mast facility at the Langley Research Center. Results show that this class of torque-wheel can produce an oscillation of 2.5 cm peak-to-peak in the end point of the arm and that the wheel produces significantly less overshoot when the arm is issued an abrupt stop command from the telerobotic input station.

SyRoTek--Distance Teaching of Mobile Robotics

ERIC Educational Resources Information Center

Kulich, M.; Chudoba, J.; Kosnar, K.; Krajnik, T.; Faigl, J.; Preucil, L.

2013-01-01

E-learning is a modern and effective approach for training in various areas and at different levels of education. This paper gives an overview of SyRoTek, an e-learning platform for mobile robotics, artificial intelligence, control engineering, and related domains. SyRoTek provides remote access to a set of fully autonomous mobile robots placed in…

Simplified planar model of a car steering system with rack and pinion and McPherson suspension

NASA Astrophysics Data System (ADS)

Knapczyk, J.; Kucybała, P.

2016-09-01

The paper presents the analysis and optimization of steering system with rack and pinion and McPherson suspension using spatial model and equivalent simplified planar model. The dimension of the steering linkage that give minimum steering error can be estimated using planar model. The steering error is defined as the difference between the actual angle made by the outer front wheel during steering manoeuvers and the calculated angle for the same wheel based on the Ackerman principle. For a given linear rack displacement, a specified steering arms angular displacements are determined while simultaneously ensuring best transmission angle characteristics (i) without and (ii) with imposing linear correlation between input and output. Numerical examples are used to illustrate the proposed method.

Portable control device for networked mobile robots

DOEpatents

Feddema, John T.; Byrne, Raymond H.; Bryan, Jon R.; Harrington, John J.; Gladwell, T. Scott

2002-01-01

A handheld control device provides a way for controlling one or multiple mobile robotic vehicles by incorporating a handheld computer with a radio board. The device and software use a personal data organizer as the handheld computer with an additional microprocessor and communication device on a radio board for use in controlling one robot or multiple networked robots.

Perspectives on mobile robots as tools for child development and pediatric rehabilitation.

PubMed

Michaud, François; Salter, Tamie; Duquette, Audrey; Laplante, Jean-François

2007-01-01

Mobile robots (i.e., robots capable of translational movements) can be designed to become interesting tools for child development studies and pediatric rehabilitation. In this article, the authors present two of their projects that involve mobile robots interacting with children: One is a spherical robot deployed in a variety of contexts, and the other is mobile robots used as pedagogical tools for children with pervasive developmental disorders. Locomotion capability appears to be key in creating meaningful and sustained interactions with children: Intentional and purposeful motion is an implicit appealing factor in obtaining children's attention and engaging them in interaction and learning. Both of these projects started with robotic objectives but are revealed to be rich sources of interdisciplinary collaborations in the field of assistive technology. This article presents perspectives on how mobile robots can be designed to address the requirements of child-robot interactions and studies. The authors also argue that mobile robot technology can be a useful tool in rehabilitation engineering, reaching its full potential through strong collaborations between roboticists and pediatric specialists.

Trajectory tracking control for a nonholonomic mobile robot under ROS

NASA Astrophysics Data System (ADS)

Lakhdar Besseghieur, Khadir; Trębiński, Radosław; Kaczmarek, Wojciech; Panasiuk, Jarosław

2018-05-01

In this paper, the implementation of the trajectory tracking control strategy on a ROS-based mobile robot is considered. Our test-bench is the nonholonomic mobile robot ‘TURTLEBOT’. ROS facilitates considerably setting-up a suitable environment to test the designed controller. Our aim is to develop a framework using ROS concepts so that a trajectory tracking controller can be implemented on any ROS-enabled mobile robot. Practical experiments with ‘TURTLEBOT’ are conducted to assess the framework reliability.

A Mobile Service Robot for Life Science Laboratories

NASA Astrophysics Data System (ADS)

Schulenburg, Erik; Elkmann, Norbert; Fritzsche, Markus; Teutsch, Christian

In this paper we presents a project that is developing a mobile service robot to assist users in biological and pharmaceutical laboratories by executing routine jobs such as filling and transporting microplates. A preliminary overview of the design of the mobile platform with a robotic arm is provided. Safety aspects are one focus of the project since the robot and humans will share a common environment. Hence, several safety sensors such as laser scanners, thermographie components and artificial skin are employed. These are described along with the approaches to object recognition.

mobilityRERC state of the science conference: Considerations for developing an evidence base for wheeled mobility and seating service delivery.

PubMed

Cohen, Laura; Greer, Nancy; Berliner, Elise; Sprigle, Stephen

2013-11-01

This article, developed as background content for discussion during the Mobility Rehabilitation Engineering Research Center State of the Science Conference, reviews research surrounding wheeled mobility and seating (WMS) service delivery, discusses the challenges of improving clinical decision-making, and discusses research approaches used to study and improve health services in other practice areas that might be leveraged to develop the evidence base for WMS. Narrative literature review. An overview of existing research found general agreement across models of WMS service delivery but little high quality evidence to support the recommended approaches and few studies of the relationship between service delivery steps and individual patient outcomes. The definition of successful clinical decision-making is different for different stakeholders. Clinical decision-making should incorporate the best available evidence along with patient values, preferences, circumstances, and clinical expertise. To advance the evidence base for WMS service delivery, alternatives to randomized controlled trials should be considered and reliable and valid outcome measures developed. Technological advances offer tremendous opportunities for individuals with complex rehabilitation technology needs. However, with ongoing scrutiny of WMS service delivery there is an increased need for evidence to support the clinical decision-making process and to support evidence-based coverage policies for WMS services and technologies. An evidence base for wheeled mobility and seating services is an important component of the clinical decision-making process. At present, there is little evidence regarding essential components of the wheeled mobility and seating evaluation or the relationship between the evaluation process and patient outcomes. Many factors can confound this relationship and present challenges to research in this area. All stakeholders (i.e. clinicians, rehabilitation technology suppliers

Rice-obot 1: An intelligent autonomous mobile robot

NASA Technical Reports Server (NTRS)

Defigueiredo, R.; Ciscon, L.; Berberian, D.

1989-01-01

The Rice-obot I is the first in a series of Intelligent Autonomous Mobile Robots (IAMRs) being developed at Rice University's Cooperative Intelligent Mobile Robots (CIMR) lab. The Rice-obot I is mainly designed to be a testbed for various robotic and AI techniques, and a platform for developing intelligent control systems for exploratory robots. Researchers present the need for a generalized environment capable of combining all of the control, sensory and knowledge systems of an IAMR. They introduce Lisp-Nodes as such a system, and develop the basic concepts of nodes, messages and classes. Furthermore, they show how the control system of the Rice-obot I is implemented as sub-systems in Lisp-Nodes.

Optical designs for MWIR and four quadrant detectors by using beam steering methods in missile applications

NASA Astrophysics Data System (ADS)

Sakarya, Doǧan Uǧur

2017-10-01

Beam steering optical arrangement needs less volume envelope for same field of regard than other gimbal approaches. Both for imaging and four quadrant missile applications, volume is critical parameter limiting system performance. Therefore, a conceptual design of beam steering method has been focused on both imaging and four quadrant missiles. In this study; four different optical designs have been made by using both beam steering and regular method for mid-wave infra-red imaging and four quadrant systems. Optical designs performances have been illustrated in simulation results. By using manufactured Risley prisms, some experimental results are conducted to compare simulations results.

Self-reported difficulty and preferences of wheeled mobility device users for simulated low-floor bus boarding, interior circulation and disembarking.

PubMed

D'Souza, Clive; Paquet, Victor L; Lenker, James A; Steinfeld, Edward

2017-11-13

Low ridership of public transit buses among wheeled mobility device users suggests the need to identify vehicle design conditions that are either particularly accommodating or challenging. The objective of this study was to determine the effects of low-floor bus interior seating configuration and passenger load on wheeled mobility device user-reported difficulty, overall acceptability and design preference. Forty-eight wheeled mobility users evaluated three interior design layouts at two levels of passenger load (high vs. low) after simulating boarding and disembarking tasks on a static full-scale low-floor bus mockup. User self-reports of task difficulty, acceptability and design preference were analyzed across the different test conditions. Ramp ascent was the most difficult task for manual wheelchair users relative to other tasks. The most difficult tasks for users of power wheelchairs and scooters were related to interior circulation, including moving to the securement area, entry and positioning in the securement area and exiting the securement area. Boarding and disembarking at the rear doorway was significantly more acceptable and preferred compared to the layouts with front doorways. Understanding transit usability barriers, perceptions and preferences among wheeled mobility users is an important consideration for clinicians who recommend mobility-related device interventions to those who use public transportation. Implications for Rehabilitation In order to maximize community participation opportunities for wheeled mobility users, clinicians should consider potential public transit barriers during the processes of wheelchair device selection and skills training. Usability barriers experienced by wheeled mobility device users on transit vehicles differ by mobility device type and vehicle configurations. Full-scale environment simulations are an effective means of identifying usability barriers and design needs in people with mobility impairments and may

Four-Wheel Drivescapes: Embodied Understandings of the Kimberley

ERIC Educational Resources Information Center

Waitt, Gordon; Lane, Ruth

2007-01-01

In this paper, we explore understandings of the Kimberley as wilderness through the embodied knowledge of sites encountered on the travels of four-wheel drivers. We critically review attempts to conceptualise the social role of automobiles in touring practices then turn to non-representational theory to develop our own conceptual framework of…

Independent Orbiter Assessment (IOA): Analysis of the nose wheel steering subsystem

NASA Technical Reports Server (NTRS)

Mediavilla, Anthony Scott

1986-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The independent analysis results for the Orbiter Nose Wheel Steering (NWS) hardware are documented. The NWS hardware provides primary directional control for the Orbiter vehicle during landing rollout. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. The original NWS design was envisioned as a backup system to differential braking for directional control of the Orbiter during landing rollout. No real effort was made to design the NWS system as fail operational. The brakes have much redundancy built into their design but the poor brake/tire performance has forced the NSTS to upgrade NWS to the primary mode of directional control during rollout. As a result, a large percentage of the NWS system components have become Potential Critical Items (PCI).

Public provision of four-wheeled walkers: contingent valuation study of economic benefit.

PubMed

Haines, Terry; Brown, Cassandra; Morrison, Jan

2008-09-01

To quantify the economic value of publicly provided four-wheeled walkers as judged by recipients in Queensland, Australia. Contingent valuation study using willingness-to-pay approach. A sample of 49 Australian older adults who received a publicly funded four-wheeled walker in the past 3 months completed the survey via telephone. A discrete choice bidding response format with a randomly selected starting bid was employed to glean valuations. This approach yielded only one non-response, and one zero dollar response. The mean (standard deviation) valuation provided was $ A 290 ($ A 167), which was $ A 84 in excess of the price paid by the public provider agency to purchase the equipment. Starting bid was significantly associated with values provided. The current public provision program of four-wheeled walkers is likely to generate net societal benefit. These findings coupled with arguments based on equity build a moderate case for the continuation of this program.

Research state-of-the-art of mobile robots in China

NASA Astrophysics Data System (ADS)

Wu, Lin; Zhao, Jinglun; Zhang, Peng; Li, Shiqing

1991-03-01

Several newly developed mobile robots in china are described in the paper. It includes masterslave telerobot sixleged robot biped walking robot remote inspection robot crawler moving robot and autonomous mobi le vehicle . Some relevant technology are also described.

High-power beam steering using phase conjugation through Brillouin-induced four-wave mixing.

PubMed

Jones, D C; Cook, G; Ridley, K D; Scott, A M

1991-10-15

We report an experimental demonstration of a beam-steering concept. A high-reflectivity phase-conjugate mirror is used to steer a high-power phase-conjugate beam using a low-power signal beam. The high reflectivity phase conjugation is achieved using Brillouin-induced four-wave mixing in a cell containing carbon disulfide.

Two-Armed, Mobile, Sensate Research Robot

NASA Technical Reports Server (NTRS)

Engelberger, J. F.; Roberts, W. Nelson; Ryan, David J.; Silverthorne, Andrew

2004-01-01

The Anthropomorphic Robotic Testbed (ART) is an experimental prototype of a partly anthropomorphic, humanoid-size, mobile robot. The basic ART design concept provides for a combination of two-armed coordination, tactility, stereoscopic vision, mobility with navigation and avoidance of obstacles, and natural-language communication, so that the ART could emulate humans in many activities. The ART could be developed into a variety of highly capable robotic assistants for general or specific applications. There is especially great potential for the development of ART-based robots as substitutes for live-in health-care aides for home-bound persons who are aged, infirm, or physically handicapped; these robots could greatly reduce the cost of home health care and extend the term of independent living. The ART is a fully autonomous and untethered system. It includes a mobile base on which is mounted an extensible torso topped by a head, shoulders, and two arms. All subsystems of the ART are powered by a rechargeable, removable battery pack. The mobile base is a differentially- driven, nonholonomic vehicle capable of a speed >1 m/s and can handle a payload >100 kg. The base can be controlled manually, in forward/backward and/or simultaneous rotational motion, by use of a joystick. Alternatively, the motion of the base can be controlled autonomously by an onboard navigational computer. By retraction or extension of the torso, the head height of the ART can be adjusted from 5 ft (1.5 m) to 6 1/2 ft (2 m), so that the arms can reach either the floor or high shelves, or some ceilings. The arms are symmetrical. Each arm (including the wrist) has a total of six rotary axes like those of the human shoulder, elbow, and wrist joints. The arms are actuated by electric motors in combination with brakes and gas-spring assists on the shoulder and elbow joints. The arms are operated under closed-loop digital control. A receptacle for an end effector is mounted on the tip of the wrist and

A multi-mode real-time terrain parameter estimation method for wheeled motion control of mobile robots

NASA Astrophysics Data System (ADS)

Li, Yuankai; Ding, Liang; Zheng, Zhizhong; Yang, Qizhi; Zhao, Xingang; Liu, Guangjun

2018-05-01

For motion control of wheeled planetary rovers traversing on deformable terrain, real-time terrain parameter estimation is critical in modeling the wheel-terrain interaction and compensating the effect of wheel slipping. A multi-mode real-time estimation method is proposed in this paper to achieve accurate terrain parameter estimation. The proposed method is composed of an inner layer for real-time filtering and an outer layer for online update. In the inner layer, sinkage exponent and internal frictional angle, which have higher sensitivity than that of the other terrain parameters to wheel-terrain interaction forces, are estimated in real time by using an adaptive robust extended Kalman filter (AREKF), whereas the other parameters are fixed with nominal values. The inner layer result can help synthesize the current wheel-terrain contact forces with adequate precision, but has limited prediction capability for time-variable wheel slipping. To improve estimation accuracy of the result from the inner layer, an outer layer based on recursive Gauss-Newton (RGN) algorithm is introduced to refine the result of real-time filtering according to the innovation contained in the history data. With the two-layer structure, the proposed method can work in three fundamental estimation modes: EKF, REKF and RGN, making the method applicable for flat, rough and non-uniform terrains. Simulations have demonstrated the effectiveness of the proposed method under three terrain types, showing the advantages of introducing the two-layer structure.

Perception for mobile robot navigation: A survey of the state of the art

NASA Technical Reports Server (NTRS)

Kortenkamp, David

1994-01-01

In order for mobile robots to navigate safely in unmapped and dynamic environments they must perceive their environment and decide on actions based on those perceptions. There are many different sensing modalities that can be used for mobile robot perception; the two most popular are ultrasonic sonar sensors and vision sensors. This paper examines the state-of-the-art in sensory-based mobile robot navigation. The first issue in mobile robot navigation is safety. This paper summarizes several competing sonar-based obstacle avoidance techniques and compares them. Another issue in mobile robot navigation is determining the robot's position and orientation (sometimes called the robot's pose) in the environment. This paper examines several different classes of vision-based approaches to pose determination. One class of approaches uses detailed, a prior models of the robot's environment. Another class of approaches triangulates using fixed, artificial landmarks. A third class of approaches builds maps using natural landmarks. Example implementations from each of these three classes are described and compared. Finally, the paper presents a completely implemented mobile robot system that integrates sonar-based obstacle avoidance with vision-based pose determination to perform a simple task.

Break in Raised Tread on Curiosity Wheel

NASA Image and Video Library

2017-03-21

Two of the raised treads, called grousers, on the left middle wheel of NASA's Curiosity Mars rover broke during the first quarter of 2017, including the one seen partially detached at the top of the wheel in this image from the Mars Hand Lens Imager (MAHLI) camera on the rover's arm. This image was taken on March 19, 2017, as part of a set used by rover team members to inspect the condition of the rover's six wheels during the 1,641st Martian day, or sol, of Curiosity's work on Mars. Holes and tears in the wheels worsened significantly during 2013 as Curiosity was crossing terrain studded with sharp rocks on the route from near its 2012 landing site to the base of Mount Sharp. Team members have used MAHLI systematically since then to watch for when any of the zig-zag shaped grousers begin to break. The last prior set of wheel-inspection images from before Sol 1641 was taken on Jan. 27, 2017, (Sol 1591) and revealed no broken grousers. Longevity testing with identical aluminum wheels on Earth indicates that when three grousers on a given wheel have broken, that wheel has reached about 60 percent of its useful life. Curiosity has driven well over 60 percent of the amount needed for reaching all the geological layers planned as the mission's science destinations, so the start of seeing broken grousers is not expected to affect the mission's operations. Curiosity's six aluminum wheels are about 20 inches (50 centimeters) in diameter and 16 inches (40 centimeters) wide. Each of the six wheels has its own drive motor, and the four corner wheels also have steering motors. http://photojournal.jpl.nasa.gov/catalog/PIA21486

Design of a steering stabilizer based on CAN bus

NASA Astrophysics Data System (ADS)

Zhan, Zhaomin; Yan, Yibin

2018-04-01

This design realizes a posture correction device of griping steering wheel based on CAN bus, which is embedded in the steering wheel of vehicles. The system aims to detect the drivers' abnormal griping postures and provides drivers with classification alerts, by combining the recorded griping postures data and the vehicle speed data that are obtained via the CAN bus. The warning information are automatically stored and retained in the device for 12 months. To enhance the alerting effect, the count of this warning message for both the latest month and the last 12 months are displayed on the dashboard panel. In addition to prevent itself from being blocked and self-detect any faults in advance, the appliance also provide a self-test function, which will communicate with the integrated instrument system in vehicle and do simulation test right after the vehicle power on. This appliance can help to urge and ensure drivers to operate the steering wheel correctly, effectively, and timely; prevent some typical incorrect behaviors which commonly happen along with the change of griping postures, such as the using cellphone, and ultimately, reduce the incidence of traffic accidents.

Laser-Camera Vision Sensing for Spacecraft Mobile Robot Navigation

NASA Technical Reports Server (NTRS)

Maluf, David A.; Khalil, Ahmad S.; Dorais, Gregory A.; Gawdiak, Yuri

2002-01-01

The advent of spacecraft mobile robots-free-flyng sensor platforms and communications devices intended to accompany astronauts or remotely operate on space missions both inside and outside of a spacecraft-has demanded the development of a simple and effective navigation schema. One such system under exploration involves the use of a laser-camera arrangement to predict relative positioning of the mobile robot. By projecting laser beams from the robot, a 3D reference frame can be introduced. Thus, as the robot shifts in position, the position reference frame produced by the laser images is correspondingly altered. Using normalization and camera registration techniques presented in this paper, the relative translation and rotation of the robot in 3D are determined from these reference frame transformations.

Effects of robot-guided passive stretching and active movement training of ankle and mobility impairments in stroke.

PubMed

Waldman, Genna; Yang, Chung-Yong; Ren, Yupeng; Liu, Lin; Guo, Xin; Harvey, Richard L; Roth, Elliot J; Zhang, Li-Qun

2013-01-01

To investigate the effects of controlled passive stretching and active movement training using a portable rehabilitation robot on stroke survivors with ankle and mobility impairment. Twenty-four patients at least 3 months post stroke were assigned to receive 6 week training using the portable robot in a research laboratory (robot group) or an instructed exercise program at home (control group). All patients underwent clinical and biomechanical evaluations in the laboratory at pre-evaluation, post-evaluation, and 6-week follow-up. Subjects in the robot group improved significantly more than that in the control group in reduction in spasticity measured by modified Ashworth scale, mobility by Stroke Rehabilitation Assessment of Movement (STREAM), the balance by Berg balance score, dorsiflexion passive range of motion, dorsiflexion strength, and load bearing on the affected limb during gait after 6-week training. Both groups improved in the STREAM, dorsiflexion active range of motion and dorsiflexor strength after the training, which were retained in the follow-up evaluation. Robot-assisted passive stretching and active movement training is effective in improving motor function and mobility post stroke.

The meaning ascribed to wheeled mobility devices by individuals who use wheelchairs and scooters: a metasynthesis.

PubMed

Ripat, Jacquie; Verdonck, Michele; Carter, Roger Jaffrey

2018-04-01

To synthesize qualitative study findings on the meaning ascribed to wheelchairs and wheeled mobility devices (WMD) by WMD users. Bibliographic databases were systematically searched up to January 2015 to identify relevant papers. Reviewers selected studies, assessed methodological quality and thematically synthesized findings using a metasynthesis process described by Thomas and Harden (2008). Twenty articles were included. Four descriptive themes emerged: physical environment interaction; sociocultural experiences; participation in activities and occupations; and WMD-self relationship. WMD use was found to be a complex experience that can fluctuate through interaction with aspects of the environment and opportunities for participation. The analytic theme, dynamic duality of WMD experience, addressed the simultaneous enabling and disabling aspects of WMD use. Metasyntheses enable researchers to gain a deeper understanding of issues by examining findings across studies. Findings of this study provide a framework for understanding the complexity of WMD use. The framework has practical applications for clinicians and users of WMD in understanding the experience of WMD to be neither singular nor static. Implications for Rehabilitation The meaning of wheeled mobility device (WMD) use is dynamically influenced by the environment and opportunities afforded for occupational and social participation. A duality of experiences can emerge for WMD users, where wheeled mobility use can be at the same time positive and negative, based on the interaction with the environment. Clinicians need to determine the meaning that each individual user ascribes to the WMD, and to consider how that meaning may change over time. By understanding the meaning ascribed to WMD use by individuals, clinicians can be better prepared to work with the WMD users to address negative reinforcers of the experience in physical and sociocultural environments as well as highlighting the positive experiences.

Time response for sensor sensed to actuator response for mobile robotic system

NASA Astrophysics Data System (ADS)

Amir, N. S.; Shafie, A. A.

2017-11-01

Time and performance of a mobile robot are very important in completing the tasks given to achieve its ultimate goal. Tasks may need to be done within a time constraint to ensure smooth operation of a mobile robot and can result in better performance. The main purpose of this research was to improve the performance of a mobile robot so that it can complete the tasks given within time constraint. The problem that is needed to be solved is to minimize the time interval between sensor detection and actuator response. The research objective is to analyse the real time operating system performance of sensors and actuators on one microcontroller and on two microcontroller for a mobile robot. The task for a mobile robot for this research is line following with an obstacle avoidance. Three runs will be carried out for the task and the time between the sensors senses to the actuator responses were recorded. Overall, the results show that two microcontroller system have better response time compared to the one microcontroller system. For this research, the average difference of response time is very important to improve the internal performance between the occurrence of a task, sensors detection, decision making and actuator response of a mobile robot. This research helped to develop a mobile robot with a better performance and can complete task within the time constraint.

RoCoMAR: robots' controllable mobility aided routing and relay architecture for mobile sensor networks.

PubMed

Le, Duc Van; Oh, Hoon; Yoon, Seokhoon

2013-07-05

In a practical deployment, mobile sensor network (MSN) suffers from a low performance due to high node mobility, time-varying wireless channel properties, and obstacles between communicating nodes. In order to tackle the problem of low network performance and provide a desired end-to-end data transfer quality, in this paper we propose a novel ad hoc routing and relaying architecture, namely RoCoMAR (Robots' Controllable Mobility Aided Routing) that uses robotic nodes' controllable mobility. RoCoMAR repeatedly performs link reinforcement process with the objective of maximizing the network throughput, in which the link with the lowest quality on the path is identified and replaced with high quality links by placing a robotic node as a relay at an optimal position. The robotic node resigns as a relay if the objective is achieved or no more gain can be obtained with a new relay. Once placed as a relay, the robotic node performs adaptive link maintenance by adjusting its position according to the movements of regular nodes. The simulation results show that RoCoMAR outperforms existing ad hoc routing protocols for MSN in terms of network throughput and end-to-end delay.

RoCoMAR: Robots' Controllable Mobility Aided Routing and Relay Architecture for Mobile Sensor Networks

PubMed Central

Van Le, Duc; Oh, Hoon; Yoon, Seokhoon

2013-01-01

In a practical deployment, mobile sensor network (MSN) suffers from a low performance due to high node mobility, time-varying wireless channel properties, and obstacles between communicating nodes. In order to tackle the problem of low network performance and provide a desired end-to-end data transfer quality, in this paper we propose a novel ad hoc routing and relaying architecture, namely RoCoMAR (Robots' Controllable Mobility Aided Routing) that uses robotic nodes' controllable mobility. RoCoMAR repeatedly performs link reinforcement process with the objective of maximizing the network throughput, in which the link with the lowest quality on the path is identified and replaced with high quality links by placing a robotic node as a relay at an optimal position. The robotic node resigns as a relay if the objective is achieved or no more gain can be obtained with a new relay. Once placed as a relay, the robotic node performs adaptive link maintenance by adjusting its position according to the movements of regular nodes. The simulation results show that RoCoMAR outperforms existing ad hoc routing protocols for MSN in terms of network throughput and end-to-end delay. PMID:23881134

Positional estimation techniques for an autonomous mobile robot

NASA Technical Reports Server (NTRS)

Nandhakumar, N.; Aggarwal, J. K.

1990-01-01

Techniques for positional estimation of a mobile robot navigation in an indoor environment are described. A comprehensive review of the various positional estimation techniques studied in the literature is first presented. The techniques are divided into four different types and each of them is discussed briefly. Two different kinds of environments are considered for positional estimation; mountainous natural terrain and an urban, man-made environment with polyhedral buildings. In both cases, the robot is assumed to be equipped with single visual camera that can be panned and tilted and also a 3-D description (world model) of the environment is given. Such a description could be obtained from a stereo pair of aerial images or from the architectural plans of the buildings. Techniques for positional estimation using the camera input and the world model are presented.

A mobile robots experimental environment with event-based wireless communication.

PubMed

Guinaldo, María; Fábregas, Ernesto; Farias, Gonzalo; Dormido-Canto, Sebastián; Chaos, Dictino; Sánchez, José; Dormido, Sebastián

2013-07-22

An experimental platform to communicate between a set of mobile robots through a wireless network has been developed. The mobile robots get their position through a camera which performs as sensor. The video images are processed in a PC and a Waspmote card sends the corresponding position to each robot using the ZigBee standard. A distributed control algorithm based on event-triggered communications has been designed and implemented to bring the robots into the desired formation. Each robot communicates to its neighbors only at event times. Furthermore, a simulation tool has been developed to design and perform experiments with the system. An example of usage is presented.

A Mobile Robots Experimental Environment with Event-Based Wireless Communication

PubMed Central

Guinaldo, María; Fábregas, Ernesto; Farias, Gonzalo; Dormido-Canto, Sebastián; Chaos, Dictino; Sánchez, José; Dormido, Sebastián

2013-01-01

An experimental platform to communicate between a set of mobile robots through a wireless network has been developed. The mobile robots get their position through a camera which performs as sensor. The video images are processed in a PC and a Waspmote card sends the corresponding position to each robot using the ZigBee standard. A distributed control algorithm based on event-triggered communications has been designed and implemented to bring the robots into the desired formation. Each robot communicates to its neighbors only at event times. Furthermore, a simulation tool has been developed to design and perform experiments with the system. An example of usage is presented. PMID:23881139

Adaptive Gait Control for a Quadruped Robot on 3D Path Planning

NASA Astrophysics Data System (ADS)

Igarashi, Hiroshi; Kakikura, Masayoshi

A legged walking robot is able to not only move on irregular terrain but also change its posture. For example, the robot can pass under overhead obstacles by crouching. The purpose of our research is to realize efficient path planning with a quadruped robot. Therefore, the path planning is expected to extended in three dimensions because of the mobility. However, some issues of the quadruped robot, which are instability, workspace limitation, deadlock and slippage, complicate realizing such application. In order to improve these issues and reinforce the mobility, a new static gait pattern for a quadruped robot, called TFG: Trajectory Following Gait, is proposed. The TFG intends to obtain high controllability like a wheel robot. Additionally, the TFG allows to change it posture during the walk. In this paper, some experimental results show that the TFG improves the issues and it is available for efficient locomotion in three dimensional environment.

Brain Computer Interfaces for Enhanced Interaction with Mobile Robot Agents

DTIC Science & Technology

2016-07-27

synergistic and complementary way. This project focused on acquiring a mobile robotic agent platform that can be used to explore these interfaces...providing a test environment where the human control of a robot agent can be experimentally validated in 1. REPORT DATE (DD-MM-YYYY) 4. TITLE AND...Distribution Unlimited UU UU UU UU 27-07-2016 17-Sep-2013 16-Sep-2014 Final Report: Brain Computer Interfaces for Enhanced Interactions with Mobile Robot

Applied design methodology for lunar rover elastic wheel

NASA Astrophysics Data System (ADS)

Cardile, Diego; Viola, Nicole; Chiesa, Sergio; Rougier, Alessandro

2012-12-01

In recent years an increasing interest in the Moon surface operations has been experienced. In the future robotic and manned missions of Moon surface exploration will be fundamental in order to lay the groundwork for more ambitious space exploration programs. Surface mobility systems will be the key elements to ensure an efficient and safe Moon exploration. Future lunar rovers are likely to be heavier and able to travel longer distances than the previously developed Moon rover systems. The Lunar Roving Vehicle (LRV) is the only manned rover, which has so far been launched and used on the Moon surface. Its mobility system included flexible wheels that cannot be scaled to the heavier and longer range vehicles. Thus the previously developed wheels are likely not to be suitable for the new larger vehicles. Taking all these considerations into account, on the basis of the system requirements and assumptions, several wheel concepts have been discussed and evaluated through a trade-off analysis. Semi-empirical equations have been utilized to predict the wheel geometrical characteristics, as well as to estimate the motion resistances and the ability of the system to generate thrust. A numerical model has also been implemented, in order to define more into the details the whole wheel design, in terms of wheel geometry and physical properties. As a result of the trade-off analysis, the ellipse wheel concept has shown the best behavior in terms of stiffness, mass budget and dynamic performance. The results presented in the paper have been obtained in cooperation with Thales Alenia Space-Italy and Sicme motori, in the framework of a regional program called STEPS . STEPS-Sistemi e Tecnologie per l'EsPlorazione Spaziale is a research project co-financed by Piedmont Region and firms and universities of the Piedmont Aerospace District in the ambit of the P.O.R-F.E.S.R. 2007-2013 program.

Walk and roll robot

NASA Technical Reports Server (NTRS)

Wilson, Andrew (Inventor); Punnoose, Andrew (Inventor); Strausser, Katherine (Inventor); Parikh, Neil (Inventor)

2011-01-01

A mobile robotic unit features a main body, a plurality of legs for supporting the main body on and moving the main body in forward and reverse directions about a base surface, and a drive assembly. According to an exemplary embodiment each leg includes a respective pivotal hip joint, a pivotal knee joint, and a wheeled foot adapted to roll along the base surface. Also according to an exemplary embodiments the drive assembly includes a motor operatively associated with the hip and knee joints and the wheeled foot for independently driving pivotal movement of the hip joint and the knee joint and rolling motion of the wheeled foot. The hip joint may include a ball-and-socket-type joint interconnecting top portion of the leg to the main body, such that the hip joint is adapted to pivot said leg in a direction transverse to a forward-and-reverse direction.

Mobile robots exploration through cnn-based reinforcement learning.

PubMed

Tai, Lei; Liu, Ming

2016-01-01

Exploration in an unknown environment is an elemental application for mobile robots. In this paper, we outlined a reinforcement learning method aiming for solving the exploration problem in a corridor environment. The learning model took the depth image from an RGB-D sensor as the only input. The feature representation of the depth image was extracted through a pre-trained convolutional-neural-networks model. Based on the recent success of deep Q-network on artificial intelligence, the robot controller achieved the exploration and obstacle avoidance abilities in several different simulated environments. It is the first time that the reinforcement learning is used to build an exploration strategy for mobile robots through raw sensor information.

Local Free-Space Mapping and Path Guidance for Mobile Robots.

DTIC Science & Technology

1988-03-01

CM a CD U 00 Technical Document 1227 March 1988 Local Free- Space Mapping o and Path Guidance for Mobile Robots o William T. Gex N’% Nancy L. Campbell...TITLE (inludvSeocutCl&sas~o*) Local Free- Space Mapping and Path Guidance for Mobile Robots 12. PERSONAL AUTHOR(S) William T. Gex and Nancy L...Description of Robot System... 2 Free- Space Mapping ... 4 Map Construction ... 4 . ,12pping Examplk... 5 ’ft Sensor Unreliability... 8 % Path Guidance

Exhaustive geographic search with mobile robots along space-filling curves

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spires, S.V.; Goldsmith, S.Y.

1998-03-01

Swarms of mobile robots can be tasked with searching a geographic region for targets of interest, such as buried land mines. The authors assume that the individual robots are equipped with sensors tuned to the targets of interest, that these sensors have limited range, and that the robots can communicate with one another to enable cooperation. How can a swarm of cooperating sensate robots efficiently search a given geographic region for targets in the absence of a priori information about the target`s locations? Many of the obvious approaches are inefficient or lack robustness. One efficient approach is to have themore » robots traverse a space-filling curve. For many geographic search applications, this method is energy-frugal, highly robust, and provides guaranteed coverage in a finite time that decreases as the reciprocal of the number of robots sharing the search task. Furthermore, it minimizes the amount of robot-to-robot communication needed for the robots to organize their movements. This report presents some preliminary results from applying the Hilbert space-filling curve to geographic search by mobile robots.« less

A robotic wheelchair trainer: design overview and a feasibility study

PubMed Central

2010-01-01

Background Experiencing independent mobility is important for children with a severe movement disability, but learning to drive a powered wheelchair can be labor intensive, requiring hand-over-hand assistance from a skilled therapist. Methods To improve accessibility to training, we developed a robotic wheelchair trainer that steers itself along a course marked by a line on the floor using computer vision, haptically guiding the driver's hand in appropriate steering motions using a force feedback joystick, as the driver tries to catch a mobile robot in a game of "robot tag". This paper provides a detailed design description of the computer vision and control system. In addition, we present data from a pilot study in which we used the chair to teach children without motor impairment aged 4-9 (n = 22) to drive the wheelchair in a single training session, in order to verify that the wheelchair could enable learning by the non-impaired motor system, and to establish normative values of learning rates. Results and Discussion Training with haptic guidance from the robotic wheelchair trainer improved the steering ability of children without motor impairment significantly more than training without guidance. We also report the results of a case study with one 8-year-old child with a severe motor impairment due to cerebral palsy, who replicated the single-session training protocol that the non-disabled children participated in. This child also improved steering ability after training with guidance from the joystick by an amount even greater than the children without motor impairment. Conclusions The system not only provided a safe, fun context for automating driver's training, but also enhanced motor learning by the non-impaired motor system, presumably by demonstrating through intuitive movement and force of the joystick itself exemplary control to follow the course. The case study indicates that a child with a motor system impaired by CP can also gain a short-term benefit

A robotic wheelchair trainer: design overview and a feasibility study.

PubMed

Marchal-Crespo, Laura; Furumasu, Jan; Reinkensmeyer, David J

2010-08-13

Experiencing independent mobility is important for children with a severe movement disability, but learning to drive a powered wheelchair can be labor intensive, requiring hand-over-hand assistance from a skilled therapist. To improve accessibility to training, we developed a robotic wheelchair trainer that steers itself along a course marked by a line on the floor using computer vision, haptically guiding the driver's hand in appropriate steering motions using a force feedback joystick, as the driver tries to catch a mobile robot in a game of "robot tag". This paper provides a detailed design description of the computer vision and control system. In addition, we present data from a pilot study in which we used the chair to teach children without motor impairment aged 4-9 (n = 22) to drive the wheelchair in a single training session, in order to verify that the wheelchair could enable learning by the non-impaired motor system, and to establish normative values of learning rates. Training with haptic guidance from the robotic wheelchair trainer improved the steering ability of children without motor impairment significantly more than training without guidance. We also report the results of a case study with one 8-year-old child with a severe motor impairment due to cerebral palsy, who replicated the single-session training protocol that the non-disabled children participated in. This child also improved steering ability after training with guidance from the joystick by an amount even greater than the children without motor impairment. The system not only provided a safe, fun context for automating driver's training, but also enhanced motor learning by the non-impaired motor system, presumably by demonstrating through intuitive movement and force of the joystick itself exemplary control to follow the course. The case study indicates that a child with a motor system impaired by CP can also gain a short-term benefit from driver's training with haptic guidance.

Intelligent mobility research for robotic locomotion in complex terrain

NASA Astrophysics Data System (ADS)

Trentini, Michael; Beckman, Blake; Digney, Bruce; Vincent, Isabelle; Ricard, Benoit

2006-05-01

The objective of the Autonomous Intelligent Systems Section of Defence R&D Canada - Suffield is best described by its mission statement, which is "to augment soldiers and combat systems by developing and demonstrating practical, cost effective, autonomous intelligent systems capable of completing military missions in complex operating environments." The mobility requirement for ground-based mobile systems operating in urban settings must increase significantly if robotic technology is to augment human efforts in these roles and environments. The intelligence required for autonomous systems to operate in complex environments demands advances in many fields of robotics. This has resulted in large bodies of research in areas of perception, world representation, and navigation, but the problem of locomotion in complex terrain has largely been ignored. In order to achieve its objective, the Autonomous Intelligent Systems Section is pursuing research that explores the use of intelligent mobility algorithms designed to improve robot mobility. Intelligent mobility uses sensing, control, and learning algorithms to extract measured variables from the world, control vehicle dynamics, and learn by experience. These algorithms seek to exploit available world representations of the environment and the inherent dexterity of the robot to allow the vehicle to interact with its surroundings and produce locomotion in complex terrain. The primary focus of the paper is to present the intelligent mobility research within the framework of the research methodology, plan and direction defined at Defence R&D Canada - Suffield. It discusses the progress and future direction of intelligent mobility research and presents the research tools, topics, and plans to address this critical research gap. This research will create effective intelligence to improve the mobility of ground-based mobile systems operating in urban settings to assist the Canadian Forces in their future urban operations.

Stability enhancement and fuel economy of the 4-wheel-drive hybrid electric vehicles by optimal tyre force distribution

NASA Astrophysics Data System (ADS)

Goodarzi, Avesta; Mohammadi, Masoud

2014-04-01

In this paper, vehicle stability control and fuel economy for a 4-wheel-drive hybrid vehicle are investigated. The integrated controller is designed within three layers. The first layer determines the total yaw moment and total lateral force made by using an optimal controller method to follow the desired dynamic behaviour of a vehicle. The second layer determines optimum tyre force distribution in order to optimise tyre usage and find out how the tyres should share longitudinal and lateral forces to achieve a target vehicle response under the assumption that all four wheels can be independently steered, driven, and braked. In the third layer, the active steering, wheel slip, and electrical motor torque controllers are designed. In the front axle, internal combustion engine (ICE) is coupled to an electric motor (EM). The control strategy has to determine the power distribution between ICE and EM to minimise fuel consumption and allowing the vehicle to be charge sustaining. Finally, simulations performed in MATLAB/SIMULINK environment show that the proposed structure could enhance the vehicle stability and fuel economy in different manoeuvres.

A new model to compute the desired steering torque for steer-by-wire vehicles and driving simulators

NASA Astrophysics Data System (ADS)

Fankem, Steve; Müller, Steffen

2014-05-01

This paper deals with the control of the hand wheel actuator in steer-by-wire (SbW) vehicles and driving simulators (DSs). A novel model for the computation of the desired steering torque is presented. The introduced steering torque computation does not only aim to generate a realistic steering feel, which means that the driver should not miss the basic steering functionality of a modern conventional steering system such as an electric power steering (EPS) or hydraulic power steering (HPS), and this in every driving situation. In addition, the modular structure of the steering torque computation combined with suitably selected tuning parameters has the objective to offer a high degree of customisability of the steering feel and thus to provide each driver with his preferred steering feel in a very intuitive manner. The task and the tuning of each module are firstly described. Then, the steering torque computation is parameterised such that the steering feel of a series EPS system is reproduced. For this purpose, experiments are conducted in a hardware-in-the-loop environment where a test EPS is mounted on a steering test bench coupled with a vehicle simulator and parameter identification techniques are applied. Subsequently, how appropriate the steering torque computation mimics the test EPS system is objectively evaluated with respect to criteria concerning the steering torque level and gradient, the feedback behaviour and the steering return ability. Finally, the intuitive tuning of the modular steering torque computation is demonstrated for deriving a sportier steering feel configuration.

Method of Controlling Steering of a Ground Vehicle

NASA Technical Reports Server (NTRS)

Guo, Raymond (Inventor); Atluri, Venkata Prasad (Inventor); Bluethmann, William J. (Inventor); Lee, Chunhao J. (Inventor); Vitale, Robert L. (Inventor); Dawson, Andrew D. (Inventor)

2016-01-01

A method of controlling steering of a vehicle through setting wheel angles of a plurality of modular electronic corner assemblies (eModules) is provided. The method includes receiving a driving mode selected from a mode selection menu. A position of a steering input device is determined in a master controller. A velocity of the vehicle is determined, in the master controller, when the determined position of the steering input device is near center. A drive mode request corresponding to the selected driving mode to the plurality of steering controllers is transmitted to the master controller. A required steering angle of each of the plurality of eModules is determined, in the master controller, as a function of the determined position of the steering input device, the determined velocity of the vehicle, and the selected first driving mode. The eModules are set to the respective determined steering angles.

Neural network-based landmark detection for mobile robot

NASA Astrophysics Data System (ADS)

Sekiguchi, Minoru; Okada, Hiroyuki; Watanabe, Nobuo

1996-03-01

The mobile robot can essentially have only the relative position data for the real world. However, there are many cases that the robot has to know where it is located. In those cases, the useful method is to detect landmarks in the real world and adjust its position using detected landmarks. In this point of view, it is essential to develop a mobile robot that can accomplish the path plan successfully using natural or artificial landmarks. However, artificial landmarks are often difficult to construct and natural landmarks are very complicated to detect. In this paper, the method of acquiring landmarks by using the sensor data from the mobile robot necessary for planning the path is described. The landmark we discuss here is the natural one and is composed of the compression of sensor data from the robot. The sensor data is compressed and memorized by using five layered neural network that is called a sand glass model. The input and output data that neural network should learn is the sensor data of the robot that are exactly the same. Using the intermediate output data of the network, a compressed data is obtained, which expresses a landmark data. If the sensor data is ambiguous or enormous, it is easy to detect the landmark because the data is compressed and classified by the neural network. Using the backward three layers, the compressed landmark data is expanded to original data at some level. The studied neural network categorizes the detected sensor data to the known landmark.

Agile and dexterous robot for inspection and EOD operations

NASA Astrophysics Data System (ADS)

Handelman, David A.; Franken, Gordon H.; Komsuoglu, Haldun

2010-04-01

The All-Terrain Biped (ATB) robot is an unmanned ground vehicle with arms, legs and wheels designed to drive, crawl, walk and manipulate objects for inspection and explosive ordnance disposal tasks. This paper summarizes on-going development of the ATB platform. Control technology for semi-autonomous legged mobility and dual-arm dexterity is described as well as preliminary simulation and hardware test results. Performance goals include driving on flat terrain, crawling on steep terrain, walking on stairs, opening doors and grasping objects. Anticipated benefits of the adaptive mobility and dexterity of the ATB platform include increased robot agility and autonomy for EOD operations, reduced operator workload and reduced operator training and skill requirements.

In-situ soil sensing for planetary micro-rovers with hybrid wheel-leg systems

NASA Astrophysics Data System (ADS)

Comin Cabrera, Francisco Jose

Rover missions exploring other planets are tightly constrained regarding the trade-off between safety and traversal speed. Detecting and avoiding hazards during navigation is capital to preserve the mobility of a rover. Low traversal speeds are often enforced to assure that wheeled rovers do not become stuck in challenging terrain, hindering the performance and scientific return of the mission. Even such precautions do not guarantee safe navigation due to non-geometric hazards hidden in the terrain, such as sand traps beneath thin duricrusts. These issues motivate the research of the interaction with rough and sandy planetary terrains of conventional and innovative robot locomotion concepts. Hybrid wheel-legs combine the mechanical and control simplicity of wheeled locomotion with the enhanced mobility of legged locomotion. This concept has been rarely proposed for planetary exploration and the study of its interaction with granular terrains is at a very early stage. This research focuses on advancing the state-of-the-art of wheel-leg-soil interaction analysis and applying it through in-situ sensing to simultaneously improve the speed and safety of planetary rover missions. The semi-empirical approach used combines both theoretical modelling and experimental analysis of data obtained in laboratory and field analogues. A novel light-weight, low-power sensor system, capable of reliably detecting wheel-leg sinkage and slippage phenomena on-the-fly, is designed, implemented and tested both as part of a simplified single-wheel-leg test bed and integrated in a fully mobile micro-rover. Moreover, existing analytical models for the interaction between deformable terrain and heavily-loaded wheels or lightly-loaded legs are adapted to the generalised medium-loaded multi-legged wheel-leg case and combined into hybrid approaches for better accuracy, as validated against experimental data. Finally, the soil sensor system and analytical models proposed are used to develop and

High-Performance 3D Articulated Robot Display

NASA Technical Reports Server (NTRS)

Powell, Mark W.; Torres, Recaredo J.; Mittman, David S.; Kurien, James A.; Abramyan, Lucy

2011-01-01

In the domain of telerobotic operations, the primary challenge facing the operator is to understand the state of the robotic platform. One key aspect of understanding the state is to visualize the physical location and configuration of the platform. As there is a wide variety of mobile robots, the requirements for visualizing their configurations vary diversely across different platforms. There can also be diversity in the mechanical mobility, such as wheeled, tracked, or legged mobility over surfaces. Adaptable 3D articulated robot visualization software can accommodate a wide variety of robotic platforms and environments. The visualization has been used for surface, aerial, space, and water robotic vehicle visualization during field testing. It has been used to enable operations of wheeled and legged surface vehicles, and can be readily adapted to facilitate other mechanical mobility solutions. The 3D visualization can render an articulated 3D model of a robotic platform for any environment. Given the model, the software receives real-time telemetry from the avionics system onboard the vehicle and animates the robot visualization to reflect the telemetered physical state. This is used to track the position and attitude in real time to monitor the progress of the vehicle as it traverses its environment. It is also used to monitor the state of any or all articulated elements of the vehicle, such as arms, legs, or control surfaces. The visualization can also render other sorts of telemetered states visually, such as stress or strains that are measured by the avionics. Such data can be used to color or annotate the virtual vehicle to indicate nominal or off-nominal states during operation. The visualization is also able to render the simulated environment where the vehicle is operating. For surface and aerial vehicles, it can render the terrain under the vehicle as the avionics sends it location information (GPS, odometry, or star tracking), and locate the vehicle

Development of robotic mobility for infants: rationale and outcomes.

PubMed

Larin, Hélène M; Dennis, Carole W; Stansfield, Sharon

2012-09-01

To assess the feasibility of a robotic mobility device for infants using alternative control interfaces aimed at promoting early self-initiated mobility, and to assess the effects of a training protocol and robot experience. Observational and pre-post quantitative case studies. Standardised, research laboratory and day-care centres with toys and individuals familiar to infants. Children with and without disabilities, aged 5 months to 3 years. In each study, infants were seated over a Pioneer™ 3-DX mobile robot. Some infants controlled the directional movement of the robot by weight shifting their body on a Nintendo® Wii™ Balance Board (the WeeBot), while others used a modified joystick. Infants participated in five sessions over 2 to 5 weeks. Sessions consisted of administering a 10-minute training protocol preceded and followed by 2 to 3 minutes of free play. One child with motor impairment used a button switch array and a different experimental design. From the videotaped free-play periods, goal-directed behaviours were coded and time in motion was measured. In the training period, a scoring system was developed to measure the infants' driving performance. Preliminary outcomes indicate that infants without disabilities, aged 5 to 10 months, demonstrated significant improvement in driving performance and goal-directed movement using the WeeBot. Infants who used the joystick were less successful on all measures. Results for infants with disabilities using the WeeBot were mixed. Mobile robots offer promise to enhance the development of early self-mobility. Novel types of interfaces, such as the WeeBot, warrant further investigation. Copyright © 2012 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

Distributed cooperating processes in a mobile robot control system

NASA Technical Reports Server (NTRS)

Skillman, Thomas L., Jr.

1988-01-01

A mobile inspection robot has been proposed for the NASA Space Station. It will be a free flying autonomous vehicle that will leave a berthing unit to accomplish a variety of inspection tasks around the Space Station, and then return to its berth to recharge, refuel, and transfer information. The Flying Eye robot will receive voice communication to change its attitude, move at a constant velocity, and move to a predefined location along a self generated path. This mobile robot control system requires integration of traditional command and control techniques with a number of AI technologies. Speech recognition, natural language understanding, task and path planning, sensory abstraction and pattern recognition are all required for successful implementation. The interface between the traditional numeric control techniques and the symbolic processing to the AI technologies must be developed, and a distributed computing approach will be needed to meet the real time computing requirements. To study the integration of the elements of this project, a novel mobile robot control architecture and simulation based on the blackboard architecture was developed. The control system operation and structure is discussed.

Guidance Of A Mobile Robot Using An Omnidirectional Vision Navigation System

NASA Astrophysics Data System (ADS)

Oh, Sung J.; Hall, Ernest L.

1987-01-01

Navigation and visual guidance are key topics in the design of a mobile robot. Omnidirectional vision using a very wide angle or fisheye lens provides a hemispherical view at a single instant that permits target location without mechanical scanning. The inherent image distortion with this view and the numerical errors accumulated from vision components can be corrected to provide accurate position determination for navigation and path control. The purpose of this paper is to present the experimental results and analyses of the imaging characteristics of the omnivision system including the design of robot-oriented experiments and the calibration of raw results. Errors less than one picture element on each axis were observed by testing the accuracy and repeatability of the experimental setup and the alignment between the robot and the sensor. Similar results were obtained for four different locations using corrected results of the linearity test between zenith angle and image location. Angular error of less than one degree and radial error of less than one Y picture element were observed at moderate relative speed. The significance of this work is that the experimental information and the test of coordinated operation of the equipment provide a greater understanding of the dynamic omnivision system characteristics, as well as insight into the evaluation and improvement of the prototype sensor for a mobile robot. Also, the calibration of the sensor is important, since the results provide a cornerstone for future developments. This sensor system is currently being developed for a robot lawn mower.

Conduction Electrohydrodynamics with Mobile Electrodes: A Novel Actuation System for Untethered Robots.

PubMed

Cacucciolo, Vito; Shigemune, Hiroki; Cianchetti, Matteo; Laschi, Cecilia; Maeda, Shingo

2017-09-01

Electrohydrodynamics (EHD) refers to the direct conversion of electrical energy into mechanical energy of a fluid. Through the use of mobile electrodes, this principle is exploited in a novel fashion for designing and testing a millimeter-scale untethered robot, which is powered harvesting the energy from an external electric field. The robot is designed as an inverted sail-boat, with the thrust generated on the sail submerged in the liquid. The diffusion constant of the robot is experimentally computed, proving that its movement is not driven by thermal fluctuations, and then its kinematic and dynamic responses are characterized for different applied voltages. The results show the feasibility of using EHD with mobile electrodes for powering untethered robots and provide new evidences for the further development of this actuation system for both mobile robots and compliant actuators in soft robotics.

Conduction Electrohydrodynamics with Mobile Electrodes: A Novel Actuation System for Untethered Robots

PubMed Central

Shigemune, Hiroki; Cianchetti, Matteo; Laschi, Cecilia

2017-01-01

Electrohydrodynamics (EHD) refers to the direct conversion of electrical energy into mechanical energy of a fluid. Through the use of mobile electrodes, this principle is exploited in a novel fashion for designing and testing a millimeter‐scale untethered robot, which is powered harvesting the energy from an external electric field. The robot is designed as an inverted sail‐boat, with the thrust generated on the sail submerged in the liquid. The diffusion constant of the robot is experimentally computed, proving that its movement is not driven by thermal fluctuations, and then its kinematic and dynamic responses are characterized for different applied voltages. The results show the feasibility of using EHD with mobile electrodes for powering untethered robots and provide new evidences for the further development of this actuation system for both mobile robots and compliant actuators in soft robotics. PMID:28932659

Railway bogie vibration analysis by mathematical simulation model and a scaled four-wheel railway bogie set

NASA Astrophysics Data System (ADS)

Visayataksin, Noppharat; Sooklamai, Manon

2018-01-01

The bogie is the part that connects and transfers all the load from the vehicle body onto the railway track; interestingly the interaction between wheels and rails is the critical point for derailment of the rail vehicles. However, observing or experimenting with real bogies on rail vehicles is impossible due to the operational rules and safety concerns. Therefore, this research aimed to develop a vibration analysis set for a four-wheel railway bogie by constructing a four-wheel bogie with scale of 1:4.5. The bogie structures, including wheels and axles, were made from an aluminium alloy, equipped with springs and dampers. The bogie was driven by an electric motor using 4 round wheels instead of 2 straight rails, with linear velocity between 0 to 11.22 m/s. The data collected from the vibration analysis set was compared to the mathematical simulation model to investigate the vibration behavior of the bogie, especially the hunting motion. The results showed that vibration behavior from a scaled four-wheel railway bogie set significantly agreed with the mathematical simulation model in terms of displacement and hunting frequency. The critical speed of the wheelset was found by executing the mathematical simulation model at 13 m/s.

A neural network-based exploratory learning and motor planning system for co-robots

PubMed Central

Galbraith, Byron V.; Guenther, Frank H.; Versace, Massimiliano

2015-01-01

Collaborative robots, or co-robots, are semi-autonomous robotic agents designed to work alongside humans in shared workspaces. To be effective, co-robots require the ability to respond and adapt to dynamic scenarios encountered in natural environments. One way to achieve this is through exploratory learning, or “learning by doing,” an unsupervised method in which co-robots are able to build an internal model for motor planning and coordination based on real-time sensory inputs. In this paper, we present an adaptive neural network-based system for co-robot control that employs exploratory learning to achieve the coordinated motor planning needed to navigate toward, reach for, and grasp distant objects. To validate this system we used the 11-degrees-of-freedom RoPro Calliope mobile robot. Through motor babbling of its wheels and arm, the Calliope learned how to relate visual and proprioceptive information to achieve hand-eye-body coordination. By continually evaluating sensory inputs and externally provided goal directives, the Calliope was then able to autonomously select the appropriate wheel and joint velocities needed to perform its assigned task, such as following a moving target or retrieving an indicated object. PMID:26257640

A neural network-based exploratory learning and motor planning system for co-robots.

PubMed

Galbraith, Byron V; Guenther, Frank H; Versace, Massimiliano

2015-01-01

Collaborative robots, or co-robots, are semi-autonomous robotic agents designed to work alongside humans in shared workspaces. To be effective, co-robots require the ability to respond and adapt to dynamic scenarios encountered in natural environments. One way to achieve this is through exploratory learning, or "learning by doing," an unsupervised method in which co-robots are able to build an internal model for motor planning and coordination based on real-time sensory inputs. In this paper, we present an adaptive neural network-based system for co-robot control that employs exploratory learning to achieve the coordinated motor planning needed to navigate toward, reach for, and grasp distant objects. To validate this system we used the 11-degrees-of-freedom RoPro Calliope mobile robot. Through motor babbling of its wheels and arm, the Calliope learned how to relate visual and proprioceptive information to achieve hand-eye-body coordination. By continually evaluating sensory inputs and externally provided goal directives, the Calliope was then able to autonomously select the appropriate wheel and joint velocities needed to perform its assigned task, such as following a moving target or retrieving an indicated object.

Soft mobile robots driven by foldable dielectric elastomer actuators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Wenjie; Liu, Fan; Ma, Ziqi

A cantilever beam with elastic hinge pulled antagonistically by two dielectric elastomer (DE) membranes in tension forms a foldable actuator if one DE membrane is subject to a voltage and releases part of tension. Simply placing parallel rigid bars on the prestressed DE membranes results in enhanced actuators working in a pure shear state. We report design, analysis, fabrication, and experiment of soft mobile robots that are moved by such foldable DE actuators. We describe systematic measurement of the foldable actuators and perform theoretical analysis of such actuators based on minimization of total energy, and a good agreement is achievedmore » between model prediction and measurement. We develop two versions of prototypes of soft mobile robots driven either by two sets of DE membranes or one DE membrane and elastic springs. We demonstrate locomotion of these soft mobile robots and highlight several key design parameters that influence locomotion of the robots. A 45 g soft robot driven by a cyclic triangle voltage with amplitude 7.4 kV demonstrates maximal stroke 160 mm or maximal rolling velocity 42 mm/s. The underlying mechanics and physics of foldable DE actuators can be leveraged to develop other soft machines for various applications.« less

A Study on Wheel Sinkage and Rolling Resistance with variations in wheel geometry for Plain and Lugged wheels on TRI -1 Soil Simulant

NASA Astrophysics Data System (ADS)

Gireesh Kumar, Pala; Jayalekshmi, S.

2018-03-01

Wheel-soil Interaction studies are gaining momentum in the field of Terramechanics, but the basis is Terzaghi’s bearing capacity equation. For the current study, on a lunar soil simulant TRI – 1, two plain rigid wheels are considered, i.e., small wheel (dia. of 210 mm and width of 50 mm) and large wheel (dia. 160 mm and width 32 mm). Also, different number of lugs (N = 8, 12, 16) with various lug heights (h = 5 mm, 10 mm, 15 mm) are used. In this paper, the variation of wheel sinkages from experiments obtained for various wheel weights are examined and presented. The parameter, Coefficient of rolling resistance (CRR) is determined for various cases. Hence, rolling resistance was determined and examined from the obtained CRR for all cases. Among the cases examined, the large wheel with weight 67.44 N for plain wheels and weight 67.85 N for lugged wheel (no. of lugs = 16, and height of lugs = 5 mm) registered better mobility. Similarly, for small wheel with weight 52.189 N for plain wheel and weight 52.481 N for lugged wheel (no. of lugs = 16, and height of lugs = 5 mm) registered better mobility, a lesser rolling resistance for these cases.

A novel method of freeform surface grinding with a soft wheel based on industrial robots

NASA Astrophysics Data System (ADS)

Sha, Sheng-chun; Guo, Xiao-ling

2011-08-01

In order to meet the growing demand for high-quality images, optical elements of freeform surface are more and more applied to imaging system. However the fabrication of freeform surface optical elements is much more difficult than that of traditional spherical ones. Recent research on freeform surface manufacture often deals with precision machine tools which have limitations on dimensions and are always expensive. Little has been researched on industrial robots. In this paper, a new method of freeform surface grinding based on industrial robots was found. This method could be applied to both whole surface grinding as well as partial surface grinding. The diameter of lenses to be ground would not be restricted to the machine tool's size. In this method a high-speed-rotating soft wheel was used. The relation between removing amount and grinding time which could be called removing function was established and measured. The machining precision was achieved by means of controlling the grinding time instead of the machine tool or industrial robot itself. There are two main factors affecting the removing function: i).rotating speed of the soft wheel; ii).pressure between the wheel and the work piece. In this paper, two groups of experiments have been conducted. One is the removing function tested at constant rotating speed while under different pressure. The other is that tested under a certain pressure with variable speed. Tables and curves which can show the effect of speed and pressure on the removing efficiency have been obtained. Cause for inaccuracy between experiment data and calculated result according to the theory and the non-linearity in the curves was analyzed. Through these analyses the removing function could be concluded under certain condition including rotating speed and pressure. Finally several experiments were performed to verify the appropriateness of the removing function. It could also be concluded that this method was more efficient in comparison

Tactical mobile robots for urban search and rescue

NASA Astrophysics Data System (ADS)

Blitch, John; Sidki, Nahid; Durkin, Tim

2000-07-01

Few disasters can inspire more compassion for victims and families than those involving structural collapse. Video clips of children's bodies pulled from earthquake stricken cities and bombing sties tend to invoke tremendous grief and sorrow because of the totally unpredictable nature of the crisis and lack of even the slightest degree of negligence (such as with those who choose to ignore storm warnings). Heartbreaking stories of people buried alive for days provide a visceral and horrific perspective of some of greatest fears ever to be imagined by human beings. Current trends toward urban sprawl and increasing human discord dictates that structural collapse disasters will continue to present themselves at an alarming rate. The proliferation of domestic terrorism, HAZMAT and biological contaminants further complicates the matter further and presents a daunting problem set for Urban Search and Rescue (USAR) organizations around the world. This paper amplifies the case for robot assisted search and rescue that was first presented during the KNOBSAR project initiated at the Colorado School of Mines in 1995. It anticipates increasing technical development in mobile robot technologies and promotes their use for a wide variety of humanitarian assistance missions. Focus is placed on development of advanced robotic systems that are employed in a complementary tool-like fashion as opposed to traditional robotic approaches that portend to replace humans in hazardous tasks. Operational challenges for USAR are presented first, followed by a brief history of mobiles robot development. The paper then presents conformal robotics as a new design paradigm with emphasis on variable geometry and volumes. A section on robot perception follows with an initial attempt to characterize sensing in a volumetric manner. Collaborative rescue is then briefly discussed with an emphasis on marsupial operations and linked mobility. The paper concludes with an emphasis on Human Robot Interface

Near-Optimal Tracking Control of Mobile Robots Via Receding-Horizon Dual Heuristic Programming.

PubMed

Lian, Chuanqiang; Xu, Xin; Chen, Hong; He, Haibo

2016-11-01

Trajectory tracking control of wheeled mobile robots (WMRs) has been an important research topic in control theory and robotics. Although various tracking control methods with stability have been developed for WMRs, it is still difficult to design optimal or near-optimal tracking controller under uncertainties and disturbances. In this paper, a near-optimal tracking control method is presented for WMRs based on receding-horizon dual heuristic programming (RHDHP). In the proposed method, a backstepping kinematic controller is designed to generate desired velocity profiles and the receding horizon strategy is used to decompose the infinite-horizon optimal control problem into a series of finite-horizon optimal control problems. In each horizon, a closed-loop tracking control policy is successively updated using a class of approximate dynamic programming algorithms called finite-horizon dual heuristic programming (DHP). The convergence property of the proposed method is analyzed and it is shown that the tracking control system based on RHDHP is asymptotically stable by using the Lyapunov approach. Simulation results on three tracking control problems demonstrate that the proposed method has improved control performance when compared with conventional model predictive control (MPC) and DHP. It is also illustrated that the proposed method has lower computational burden than conventional MPC, which is very beneficial for real-time tracking control.

A Mobile, Map-Based Tasking Interface for Human-Robot Interaction

DTIC Science & Technology

2010-12-01

A MOBILE, MAP-BASED TASKING INTERFACE FOR HUMAN-ROBOT INTERACTION By Eli R. Hooten Thesis Submitted to the Faculty of the Graduate School of...SUBTITLE A Mobile, Map-Based Tasking Interface for Human-Robot Interaction 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...3 II.1 Interactive Modalities and Multi-Touch . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 II.2

Herbert: A Second Generation Mobile Robot.

DTIC Science & Technology

1988-01-01

PROJECT. TASK S Artificial Inteligence Laboratory AREA A WORK UNIT NUMBERS ’ ~ 545 Technology Square Cambridge, MA 02139 11. CONTROLLING OFFICE NAME...AD-AI93 632 WMRT: A SECOND GENERTION MOBILE ROWT(U) / MASSACHUSETTS IMST OF TECH CAMBRIDGE ARTIFICIAL INTELLIGENCE LAB R BROOKS ET AL .JAN l8 Al-M...MASSACHUSETTS INSTITUTE OF TECHNOLOGY ARTIFICIAL INTELLIGENCE LABORATORY A. I. Memo 1016 January, 1988 HERBERT: A SECOND GENERATION MOBILE ROBOT Rodney A

Using advanced computer vision algorithms on small mobile robots

NASA Astrophysics Data System (ADS)

Kogut, G.; Birchmore, F.; Biagtan Pacis, E.; Everett, H. R.

2006-05-01

The Technology Transfer project employs a spiral development process to enhance the functionality and autonomy of mobile robot systems in the Joint Robotics Program (JRP) Robotic Systems Pool by converging existing component technologies onto a transition platform for optimization. An example of this approach is the implementation of advanced computer vision algorithms on small mobile robots. We demonstrate the implementation and testing of the following two algorithms useful on mobile robots: 1) object classification using a boosted Cascade of classifiers trained with the Adaboost training algorithm, and 2) human presence detection from a moving platform. Object classification is performed with an Adaboost training system developed at the University of California, San Diego (UCSD) Computer Vision Lab. This classification algorithm has been used to successfully detect the license plates of automobiles in motion in real-time. While working towards a solution to increase the robustness of this system to perform generic object recognition, this paper demonstrates an extension to this application by detecting soda cans in a cluttered indoor environment. The human presence detection from a moving platform system uses a data fusion algorithm which combines results from a scanning laser and a thermal imager. The system is able to detect the presence of humans while both the humans and the robot are moving simultaneously. In both systems, the two aforementioned algorithms were implemented on embedded hardware and optimized for use in real-time. Test results are shown for a variety of environments.

ARK: Autonomous mobile robot in an industrial environment

NASA Technical Reports Server (NTRS)

Nickerson, S. B.; Jasiobedzki, P.; Jenkin, M.; Jepson, A.; Milios, E.; Down, B.; Service, J. R. R.; Terzopoulos, D.; Tsotsos, J.; Wilkes, D.

1994-01-01

This paper describes research on the ARK (Autonomous Mobile Robot in a Known Environment) project. The technical objective of the project is to build a robot that can navigate in a complex industrial environment using maps with permanent structures. The environment is not altered in any way by adding easily identifiable beacons and the robot relies on naturally occurring objects to use as visual landmarks for navigation. The robot is equipped with various sensors that can detect unmapped obstacles, landmarks and objects. In this paper we describe the robot's industrial environment, it's architecture, a novel combined range and vision sensor and our recent results in controlling the robot in the real-time detection of objects using their color and in the processing of the robot's range and vision sensor data for navigation.

Autonomous Navigation by a Mobile Robot

NASA Technical Reports Server (NTRS)

Huntsberger, Terrance; Aghazarian, Hrand

2005-01-01

ROAMAN is a computer program for autonomous navigation of a mobile robot on a long (as much as hundreds of meters) traversal of terrain. Developed for use aboard a robotic vehicle (rover) exploring the surface of a remote planet, ROAMAN could also be adapted to similar use on terrestrial mobile robots. ROAMAN implements a combination of algorithms for (1) long-range path planning based on images acquired by mast-mounted, wide-baseline stereoscopic cameras, and (2) local path planning based on images acquired by body-mounted, narrow-baseline stereoscopic cameras. The long-range path-planning algorithm autonomously generates a series of waypoints that are passed to the local path-planning algorithm, which plans obstacle-avoiding legs between the waypoints. Both the long- and short-range algorithms use an occupancy-grid representation in computations to detect obstacles and plan paths. Maps that are maintained by the long- and short-range portions of the software are not shared because substantial localization errors can accumulate during any long traverse. ROAMAN is not guaranteed to generate an optimal shortest path, but does maintain the safety of the rover.

Web Environment for Programming and Control of a Mobile Robot in a Remote Laboratory

ERIC Educational Resources Information Center

dos Santos Lopes, Maísa Soares; Gomes, Iago Pacheco; Trindade, Roque M. P.; da Silva, Alzira F.; de C. Lima, Antonio C.

2017-01-01

Remote robotics laboratories have been successfully used for engineering education. However, few of them use mobile robots to to teach computer science. This article describes a mobile robot Control and Programming Environment (CPE) and its pedagogical applications. The system comprises a remote laboratory for robotics, an online programming tool,…

Gas Source Localization via Behaviour Based Mobile Robot and Weighted Arithmetic Mean

NASA Astrophysics Data System (ADS)

Yeon, Ahmad Shakaff Ali; Kamarudin, Kamarulzaman; Visvanathan, Retnam; Mamduh Syed Zakaria, Syed Muhammad; Zakaria, Ammar; Munirah Kamarudin, Latifah

2018-03-01

This work is concerned with the localization of gas source in dynamic indoor environment using a single mobile robot system. Algorithms such as Braitenberg, Zig-Zag and the combination of the two were implemented on the mobile robot as gas plume searching and tracing behaviours. To calculate the gas source location, a weighted arithmetic mean strategy was used. All experiments were done on an experimental testbed consisting of a large gas sensor array (LGSA) to monitor real-time gas concentration within the testbed. Ethanol gas was released within the testbed and the source location was marked using a pattern that can be tracked by a pattern tracking system. A pattern template was also mounted on the mobile robot to track the trajectory of the mobile robot. Measurements taken by the mobile robot and the LGSA were then compared to verify the experiments. A combined total of 36.5 hours of real time experimental runs were done and the typical results from such experiments were presented in this paper. From the results, we obtained gas source localization errors between 0.4m to 1.2m from the real source location.

Differential-Drive Mobile Robot Control Design based-on Linear Feedback Control Law

NASA Astrophysics Data System (ADS)

Nurmaini, Siti; Dewi, Kemala; Tutuko, Bambang

2017-04-01

This paper deals with the problem of how to control differential driven mobile robot with simple control law. When mobile robot moves from one position to another to achieve a position destination, it always produce some errors. Therefore, a mobile robot requires a certain control law to drive the robot’s movement to the position destination with a smallest possible error. In this paper, in order to reduce position error, a linear feedback control is proposed with pole placement approach to regulate the polynoms desired. The presented work leads to an improved understanding of differential-drive mobile robot (DDMR)-based kinematics equation, which will assist to design of suitable controllers for DDMR movement. The result show by using the linier feedback control method with pole placement approach the position error is reduced and fast convergence is achieved.

Integrated mobile robot control

NASA Technical Reports Server (NTRS)

Amidi, Omead; Thorpe, Charles

1991-01-01

This paper describes the structure, implementation, and operation of a real-time mobile robot controller which integrates capabilities such as: position estimation, path specification and tracking, human interfaces, fast communication, and multiple client support. The benefits of such high-level capabilities in a low-level controller was shown by its implementation for the Navlab autonomous vehicle. In addition, performance results from positioning and tracking systems are reported and analyzed.

Integrated mobile robot control

NASA Astrophysics Data System (ADS)

Amidi, Omead; Thorpe, Chuck E.

1991-03-01

This paper describes the strucwre implementation and operation of a real-time mobile robot controller which integrates capabilities such as: position estimation path specification and hacking human interfaces fast communication and multiple client support The benefits of such high-level capabilities in a low-level controller was shown by its implementation for the Naviab autonomous vehicle. In addition performance results from positioning and tracking systems are reported and analyzed.

In-line drivetrain and four wheel drive work machine using same

DOEpatents

Hoff, Brian

2008-08-05

A four wheel drive articulated mine loader is powered by a fuel cell and propelled by a single electric motor. The drivetrain has the first axle, second axle, and motor arranged in series on the work machine chassis. Torque is carried from the electric motor to the back differential via a pinion meshed with the ring gear of the back differential. A second pinion oriented in an opposite direction away from the ring gear is coupled to a drive shaft to transfer torque from the ring gear to the differential of the front axle. Thus, the ring gear of the back differential acts both to receive torque from the motor and to transfer torque to the forward axle. The in-line drive configuration includes a single electric motor and a single reduction gear to power the four wheel drive mine loader.

Robotics

NASA Technical Reports Server (NTRS)

Ambrose, Robert O.

2007-01-01

Lunar robotic functions include: 1. Transport of crew and payloads on the surface of the moon; 2. Offloading payloads from a lunar lander; 3. Handling the deployment of surface systems; with 4. Human commanding of these functions from inside a lunar vehicle, habitat, or extravehicular (space walk), with Earth-based supervision. The systems that will perform these functions may not look like robots from science fiction. In fact, robotic functions may be automated trucks, cranes and winches. Use of this equipment prior to the crew s arrival or in the potentially long periods without crews on the surface, will require that these systems be computer controlled machines. The public release of NASA's Exploration plans at the 2nd Space Exploration Conference (Houston, December 2006) included a lunar outpost with as many as four unique mobility chassis designs. The sequence of lander offloading tasks involved as many as ten payloads, each with a unique set of geometry, mass and interface requirements. This plan was refined during a second phase study concluded in August 2007. Among the many improvements to the exploration plan were a reduction in the number of unique mobility chassis designs and a reduction in unique payload specifications. As the lunar surface system payloads have matured, so have the mobility and offloading functional requirements. While the architecture work continues, the community can expect to see functional requirements in the areas of surface mobility, surface handling, and human-systems interaction as follows: Surface Mobility 1. Transport crew on the lunar surface, accelerating construction tasks, expanding the crew s sphere of influence for scientific exploration, and providing a rapid return to an ascent module in an emergency. The crew transport can be with an un-pressurized rover, a small pressurized rover, or a larger mobile habitat. 2. Transport Extra-Vehicular Activity (EVA) equipment and construction payloads. 3. Transport habitats and

Multisensor-based human detection and tracking for mobile service robots.

PubMed

Bellotto, Nicola; Hu, Huosheng

2009-02-01

One of fundamental issues for service robots is human-robot interaction. In order to perform such a task and provide the desired services, these robots need to detect and track people in the surroundings. In this paper, we propose a solution for human tracking with a mobile robot that implements multisensor data fusion techniques. The system utilizes a new algorithm for laser-based leg detection using the onboard laser range finder (LRF). The approach is based on the recognition of typical leg patterns extracted from laser scans, which are shown to also be very discriminative in cluttered environments. These patterns can be used to localize both static and walking persons, even when the robot moves. Furthermore, faces are detected using the robot's camera, and the information is fused to the legs' position using a sequential implementation of unscented Kalman filter. The proposed solution is feasible for service robots with a similar device configuration and has been successfully implemented on two different mobile platforms. Several experiments illustrate the effectiveness of our approach, showing that robust human tracking can be performed within complex indoor environments.

Steering disturbance rejection using a physics-based neuromusculoskeletal driver model

NASA Astrophysics Data System (ADS)

Mehrabi, Naser; Sharif Razavian, Reza; McPhee, John

2015-10-01

The aim of this work is to develop a comprehensive yet practical driver model to be used in studying driver-vehicle interactions. Drivers interact with their vehicle and the road through the steering wheel. This interaction forms a closed-loop coupled human-machine system, which influences the driver's steering feel and control performance. A hierarchical approach is proposed here to capture the complexity of the driver's neuromuscular dynamics and the central nervous system in the coordination of the driver's upper extremity activities, especially in the presence of external disturbance. The proposed motor control framework has three layers: the first (or the path planning) plans a desired vehicle trajectory and the required steering angles to perform the desired trajectory; the second (or the musculoskeletal controller) actuates the musculoskeletal arm to rotate the steering wheel accordingly; and the final layer ensures the precision control and disturbance rejection of the motor control units. The physics-based driver model presented here can also provide insights into vehicle control in relaxed and tensed driving conditions, which are simulated by adjusting the driver model parameters such as cognition delay and muscle co-contraction dynamics.

Robotic Technology Efforts at the NASA/Johnson Space Center

NASA Technical Reports Server (NTRS)

Diftler, Ron

2017-01-01

The NASA/Johnson Space Center has been developing robotic systems in support of space exploration for more than two decades. The goal of the Center's Robotic Systems Technology Branch is to design and build hardware and software to assist astronauts in performing their mission. These systems include: rovers, humanoid robots, inspection devices and wearable robotics. Inspection systems provide external views of space vehicles to search for surface damage and also maneuver inside restricted areas to verify proper connections. New concepts in human and robotic rovers offer solutions for navigating difficult terrain expected in future planetary missions. An important objective for humanoid robots is to relieve the crew of "dull, dirty or dangerous" tasks allowing them more time to perform their important science and exploration missions. Wearable robotics one of the Center's newest development areas can provide crew with low mass exercise capability and also augment an astronaut's strength while wearing a space suit. This presentation will describe the robotic technology and prototypes developed at the Johnson Space Center that are the basis for future flight systems. An overview of inspection robots will show their operation on the ground and in-orbit. Rovers with independent wheel modules, crab steering, and active suspension are able to climb over large obstacles, and nimbly maneuver around others. Humanoid robots, including the First Humanoid Robot in Space: Robonaut 2, demonstrate capabilities that will lead to robotic caretakers for human habitats in space, and on Mars. The Center's Wearable Robotics Lab supports work in assistive and sensing devices, including exoskeletons, force measuring shoes, and grasp assist gloves.

Mobile app for human-interaction with sitter robots

NASA Astrophysics Data System (ADS)

Das, Sumit Kumar; Sahu, Ankita; Popa, Dan O.

2017-05-01

Human environments are often unstructured and unpredictable, thus making the autonomous operation of robots in such environments is very difficult. Despite many remaining challenges in perception, learning, and manipulation, more and more studies involving assistive robots have been carried out in recent years. In hospital environments, and in particular in patient rooms, there are well-established practices with respect to the type of furniture, patient services, and schedule of interventions. As a result, adding a robot into semi-structured hospital environments is an easier problem to tackle, with results that could have positive benefits to the quality of patient care and the help that robots can offer to nursing staff. When working in a healthcare facility, robots need to interact with patients and nurses through Human-Machine Interfaces (HMIs) that are intuitive to use, they should maintain awareness of surroundings, and offer safety guarantees for humans. While fully autonomous operation for robots is not yet technically feasible, direct teleoperation control of the robot would also be extremely cumbersome, as it requires expert user skills, and levels of concentration not available to many patients. Therefore, in our current study we present a traded control scheme, in which the robot and human both perform expert tasks. The human-robot communication and control scheme is realized through a mobile tablet app that can be customized for robot sitters in hospital environments. The role of the mobile app is to augment the verbal commands given to a robot through natural speech, camera and other native interfaces, while providing failure mode recovery options for users. Our app can access video feed and sensor data from robots, assist the user with decision making during pick and place operations, monitor the user health over time, and provides conversational dialogue during sitting sessions. In this paper, we present the software and hardware framework that

Dynamic multisensor fusion for mobile robot navigation in an indoor environment

NASA Astrophysics Data System (ADS)

Jin, Taeseok; Lee, Jang-Myung; Luk, Bing L.; Tso, Shiu K.

2001-10-01

In this study, as the preliminary step for developing a multi-purpose Autonomous robust carrier mobile robot to transport trolleys or heavy goods and serve as robotic nursing assistant in hospital wards. The aim of this paper is to present the use of multi-sensor data fusion such as sonar, CCD camera dn IR sensor for map-building mobile robot to navigate, and presents an experimental mobile robot designed to operate autonomously within both indoor and outdoor environments. Smart sensory systems are crucial for successful autonomous systems. We will give an explanation for the robot system architecture designed and implemented in this study and a short review of existing techniques, since there exist several recent thorough books and review paper on this paper. Instead we will focus on the main results with relevance to the intelligent service robot project at the Centre of Intelligent Design, Automation & Manufacturing (CIDAM). We will conclude by discussing some possible future extensions of the project. It is first dealt with the general principle of the navigation and guidance architecture, then the detailed functions recognizing environments updated, obstacle detection and motion assessment, with the first results form the simulations run.

Collaboration of Miniature Multi-Modal Mobile Smart Robots over a Network

DTIC Science & Technology

2015-08-14

theoretical research on mathematics of failures in sensor-network-based miniature multimodal mobile robots and electromechanical systems. The views...theoretical research on mathematics of failures in sensor-network-based miniature multimodal mobile robots and electromechanical systems. The...independently evolving research directions based on physics-based models of mechanical, electromechanical and electronic devices, operational constraints

Investigation of the Feasibility of an Intervention to Manage Fall Risk in Wheeled Mobility Device Users with Multiple Sclerosis.

PubMed

Rice, Laura A; Isaacs, Zadok; Ousley, Cherita; Sosnoff, Jacob

2018-01-01

Falls are a common concern for wheeled mobility device users with multiple sclerosis (MS); however, no evidence-based fall prevention programs have been developed to meet the specific needs of the population. We examine the preliminary feasibility of a fall management intervention in wheeled mobility device users with MS. Study participants were exposed to an intervention program targeting risk factors for falls, including transfer skills and seated postural control. The feasibility of the program was evaluated by assessing participant perspectives, cost, recruitment rates, study adherence, participant retention, safety, and the ability to collect primary and secondary outcomes, including fall frequency, concerns about falling, transfer quality, and seated postural control. 16 wheeled mobility device users completed the program, which was found to be feasible and was positively evaluated by participants. No adverse events were experienced. After exposure to the intervention, fall frequency significantly decreased (P < .001) and transfer quality (P = .001) and seated postural control (P = .002) significantly improved. No significant differences were found regarding concerns about falling (P = .728). This study examined the feasibility of an intervention program to manage fall risk in wheeled mobility device users with MS. The program was found to be feasible, and preliminary results showed the intervention to be effective in decreasing fall frequency. Additional testing is needed to further examine the efficacy and long-term impact of the intervention.

A mobile robot system for ground servicing operations on the space shuttle

NASA Astrophysics Data System (ADS)

Dowling, K.; Bennett, R.; Blackwell, M.; Graham, T.; Gatrall, S.; O'Toole, R.; Schempf, H.

1992-11-01

A mobile system for space shuttle servicing, the Tessellator, has been configured, designed and is currently being built and integrated. Robot tasks include chemical injection and inspection of the shuttle's thermal protection system. This paper outlines tasks, rationale, and facility requirements for the development of this system. A detailed look at the mobile system and manipulator follow with a look at mechanics, electronics, and software. Salient features of the mobile robot include omnidirectionality, high reach, high stiffness and accuracy with safety and self-reliance integral to all aspects of the design. The robot system is shown to meet task, facility, and NASA requirements in its design resulting in unprecedented specifications for a mobile-manipulation system.

A mobile robot system for ground servicing operations on the space shuttle

NASA Technical Reports Server (NTRS)

Dowling, K.; Bennett, R.; Blackwell, M.; Graham, T.; Gatrall, S.; O'Toole, R.; Schempf, H.

1992-01-01

A mobile system for space shuttle servicing, the Tessellator, has been configured, designed and is currently being built and integrated. Robot tasks include chemical injection and inspection of the shuttle's thermal protection system. This paper outlines tasks, rationale, and facility requirements for the development of this system. A detailed look at the mobile system and manipulator follow with a look at mechanics, electronics, and software. Salient features of the mobile robot include omnidirectionality, high reach, high stiffness and accuracy with safety and self-reliance integral to all aspects of the design. The robot system is shown to meet task, facility, and NASA requirements in its design resulting in unprecedented specifications for a mobile-manipulation system.

Using insects to drive mobile robots - hybrid robots bridge the gap between biological and artificial systems.

PubMed

Ando, Noriyasu; Kanzaki, Ryohei

2017-09-01

The use of mobile robots is an effective method of validating sensory-motor models of animals in a real environment. The well-identified insect sensory-motor systems have been the major targets for modeling. Furthermore, mobile robots implemented with such insect models attract engineers who aim to avail advantages from organisms. However, directly comparing the robots with real insects is still difficult, even if we successfully model the biological systems, because of the physical differences between them. We developed a hybrid robot to bridge the gap. This hybrid robot is an insect-controlled robot, in which a tethered male silkmoth (Bombyx mori) drives the robot in order to localize an odor source. This robot has the following three advantages: 1) from a biomimetic perspective, the robot enables us to evaluate the potential performance of future insect-mimetic robots; 2) from a biological perspective, the robot enables us to manipulate the closed-loop of an onboard insect for further understanding of its sensory-motor system; and 3) the robot enables comparison with insect models as a reference biological system. In this paper, we review the recent works regarding insect-controlled robots and discuss the significance for both engineering and biology. Copyright © 2017 Elsevier Ltd. All rights reserved.

Robotics in invasive cardiac electrophysiology.

PubMed

Shurrab, Mohammed; Schilling, Richard; Gang, Eli; Khan, Ejaz M; Crystal, Eugene

2014-07-01

Robotic systems allow for mapping and ablation of different arrhythmia substrates replacing hand maneuvering of intracardiac catheters with machine steering. Currently there are four commercially available robotic systems. Niobe magnetic navigation system (Stereotaxis Inc., St Louis, MO) and Sensei robotic navigation system (Hansen Medical Inc., Mountain View, CA) have an established platform with at least 10 years of clinical studies looking at their efficacy and safety. AMIGO Remote Catheter System (Catheter Robotics, Inc., Mount Olive, NJ) and Catheter Guidance Control and Imaging (Magnetecs, Inglewood, CA) are in the earlier phases of implementations with ongoing feasibility and some limited clinical studies. This review discusses the advantages and limitations related to each existing system and highlights the ideal futuristic robotic system that may include the most promising features of the current ones.

A natural-language interface to a mobile robot

NASA Technical Reports Server (NTRS)

Michalowski, S.; Crangle, C.; Liang, L.

1987-01-01

The present work on robot instructability is based on an ongoing effort to apply modern manipulation technology to serve the needs of the handicapped. The Stanford/VA Robotic Aid is a mobile manipulation system that is being developed to assist severely disabled persons (quadriplegics) in performing simple activities of everyday living in a homelike, unstructured environment. It consists of two major components: a nine degree-of-freedom manipulator and a stationary control console. In the work presented here, only the motions of the Robotic Aid's omnidirectional motion base have been considered, i.e., the six degrees of freedom of the arm and gripper have been ignored. The goal has been to develop some basic software tools for commanding the robot's motions in an enclosed room containing a few objects such as tables, chairs, and rugs. In the present work, the environmental model takes the form of a two-dimensional map with objects represented by polygons. Admittedly, such a highly simplified scheme bears little resemblance to the elaborate cognitive models of reality that are used in normal human discourse. In particular, the polygonal model is given a priori and does not contain any perceptual elements: there is no polygon sensor on board the mobile robot.

Intelligent robot control using an adaptive critic with a task control center and dynamic database

NASA Astrophysics Data System (ADS)

Hall, E. L.; Ghaffari, M.; Liao, X.; Alhaj Ali, S. M.

2006-10-01

The purpose of this paper is to describe the design, development and simulation of a real time controller for an intelligent, vision guided robot. The use of a creative controller that can select its own tasks is demonstrated. This creative controller uses a task control center and dynamic database. The dynamic database stores both global environmental information and local information including the kinematic and dynamic models of the intelligent robot. The kinematic model is very useful for position control and simulations. However, models of the dynamics of the manipulators are needed for tracking control of the robot's motions. Such models are also necessary for sizing the actuators, tuning the controller, and achieving superior performance. Simulations of various control designs are shown. Also, much of the model has also been used for the actual prototype Bearcat Cub mobile robot. This vision guided robot was designed for the Intelligent Ground Vehicle Contest. A novel feature of the proposed approach is that the method is applicable to both robot arm manipulators and robot bases such as wheeled mobile robots. This generality should encourage the development of more mobile robots with manipulator capability since both models can be easily stored in the dynamic database. The multi task controller also permits wide applications. The use of manipulators and mobile bases with a high-level control are potentially useful for space exploration, certain rescue robots, defense robots, and medical robotics aids.

Evolutionary programming-based univector field navigation method for past mobile robots.

PubMed

Kim, Y J; Kim, J H; Kwon, D S

2001-01-01

Most of navigation techniques with obstacle avoidance do not consider the robot orientation at the target position. These techniques deal with the robot position only and are independent of its orientation and velocity. To solve these problems this paper proposes a novel univector field method for fast mobile robot navigation which introduces a normalized two dimensional vector field. The method provides fast moving robots with the desired posture at the target position and obstacle avoidance. To obtain the sub-optimal vector field, a function approximator is used and trained by evolutionary programming. Two kinds of vector fields are trained, one for the final posture acquisition and the other for obstacle avoidance. Computer simulations and real experiments are carried out for a fast moving mobile robot to demonstrate the effectiveness of the proposed scheme.

Needle-tissue interactive mechanism and steering control in image-guided robot-assisted minimally invasive surgery: a review.

PubMed

Li, Pan; Yang, Zhiyong; Jiang, Shan

2018-06-01

Image-guided robot-assisted minimally invasive surgery is an important medicine procedure used for biopsy or local target therapy. In order to reach the target region not accessible using traditional techniques, long and thin flexible needles are inserted into the soft tissue which has large deformation and nonlinear characteristics. However, the detection results and therapeutic effect are directly influenced by the targeting accuracy of needle steering. For this reason, the needle-tissue interactive mechanism, path planning, and steering control are investigated in this review by searching literatures in the last 10 years, which results in a comprehensive overview of the existing techniques with the main accomplishments, limitations, and recommendations. Through comprehensive analyses, surgical simulation for insertion into multi-layer inhomogeneous tissue is verified as a primary and propositional aspect to be explored, which accurately predicts the nonlinear needle deflection and tissue deformation. Investigation of the path planning of flexible needles is recommended to an anatomical or a deformable environment which has characteristics of the tissue deformation. Nonholonomic modeling combined with duty-cycled spinning for needle steering, which tracks the tip position in real time and compensates for the deviation error, is recommended as a future research focus in the steering control in anatomical and deformable environments. Graphical abstract a Insertion force when the needle is inserted into soft tissue. b Needle deflection model when the needle is inserted into soft tissue [68]. c Path planning in anatomical environments [92]. d Duty-cycled spinning incorporated in nonholonomic needle steering [64].

Wheeled-mobility correlates of life-space and social participation in adult manual wheelchair users aged 50 and older.

PubMed

Sakakibara, Brodie M; Routhier, François; Miller, William C

2017-08-01

To characterize the life-space mobility and social participation of manual wheelchair users using objective measures of wheeled mobility. Individuals (n = 49) were included in this cross-sectional study if they were aged 50 or older, community-dwelling and used their wheelchair on a daily basis for the past 6 months. Life-space mobility and social participation were measured using the life-space assessment and late-life disability instrument. The wheeled mobility variables (distance travelled, occupancy time, number of bouts) were captured using a custom-built data logger. After controlling for age and sex, multivariate regression analyses revealed that the wheeled mobility variables accounted for 24% of the life-space variance. The number of bouts variable, however, did not account for any appreciable variance above and beyond the occupancy time and distance travelled. Occupancy time and number of bouts were significant predictors of social participation and accounted for 23% of the variance after controlling for age and sex. Occupancy time and distance travelled are statistically significant predictors of life-space mobility. Lower occupancy time may be an indicative of travel to more distant life-spaces, whereas the distance travelled is likely a better reflection of mobility within each life-space. Occupancy time and number of bouts are significant predictors of participation frequency. Implications for rehabilitation Component measures of wheelchair mobility, such as distance travelled, occupancy time and number of bouts, are important predictors of life-space mobility and social participation in adult manual wheelchair users. Lower occupancy time is an indication of travel to more distant life-spaces, whereas distance travelled is likely a better reflection of mobility within each life-space. That lower occupancy time and greater number of bouts are associated with more frequent participation raises accessibility and safety issues for manual wheelchair

A predictive wheel-soil interaction model for planetary rovers validated in testbeds and against MER Mars rover performance data

NASA Astrophysics Data System (ADS)

Richter, L.; Ellery, A.; Gao, Y.; Michaud, S.; Schmitz, N.; Weiss, S.

Successful designs of vehicles intended for operations on planetary objects outside the Earth demand, just as for terrestrial off-the-road vehicles, a careful assessment of the terrain relevant for the vehicle mission and predictions of the mobility performance to allow rational trade-off's to be made for the choice of the locomotion concept and sizing. Principal issues driving the chassis design for rovers are the stress-strain properties of the planetary surface soil, the distribution of rocks in the terrain representing potential obstacles to movement, and the gravity level on the celestial object in question. Thus far, planetary rovers have been successfully designed and operated for missions to the Earth's moon and to the planet Mars, including NASA's Mars Exploration Rovers (MER's) `Spirit' and `Opportunity' being in operation on Mars since their landings in January 2004. Here we report on the development of a wheel-soil interaction model with application to wheel sizes and wheel loads relevant to current and near-term robotic planetary rovers, i.e. wheel diameters being between about 200 and 500 mm and vertical quasistatic wheel loads in operation of roughly 100 to 200 N. Such a model clearly is indispensable for sizings of future rovers to analyse the aspect of rover mobility concerned with motion across soils. This work is presently funded by the European Space Agency (ESA) as part of the `Rover Chassis Evaluation Tools' (RCET) effort which has developed a set of S/W-implemented models for predictive mobility analysis of rovers in terms of movement on soils and across obstacles, coupled with dedicated testbeds to validate the wheel-soil models. In this paper, we outline the details of the wheel-soil modelling performed within the RCET work and present comparisons of predictions of wheel performance (motion resistance, torque vs. slip and drawbar pull vs. slip) for specific test cases with the corresponding measurements performed in the RCET single wheel

Optimal powering schemes for legged robotics

NASA Astrophysics Data System (ADS)

Muench, Paul; Bednarz, David; Czerniak, Gregory P.; Cheok, Ka C.

2010-04-01

Legged Robots have tremendous mobility, but they can also be very inefficient. These inefficiencies can be due to suboptimal control schemes, among other things. If your goal is to get from point A to point B in the least amount of time, your control scheme will be different from if your goal is to get there using the least amount of energy. In this paper, we seek a balance between these extremes by looking at both efficiency and speed. We model a walking robot as a rimless wheel, and, using Pontryagin's Maximum Principle (PMP), we find an "on-off" control for the model, and describe the switching curve between these control extremes.

Usability testing of a mobile robotic system for in-home telerehabilitation.

PubMed

Boissy, Patrick; Brière, Simon; Corriveau, Hélène; Grant, Andrew; Lauria, Michel; Michaud, François

2011-01-01

Mobile robots designed to enhance telepresence in the support of telehealth services are being considered for numerous applications. TELEROBOT is a teleoperated mobile robotic platform equipped with videoconferencingcapabilities and designed to be used in a home environment to. In this study, learnability of the system's teleoperation interface and controls was evaluated with ten rehabilitation professionals during four training sessions in a laboratory environment and in an unknown home environment while performing the execution of a standardized evaluation protocol typically used in home care. Results show that the novice teleoperators' performances on two of the four metrics used (number of command and total time) improved significantly across training sessions (ANOVAS, p<0.05) and that performance in these metrics in the last training session reflected teleoperation abilities seen in the unknown home environment during navigation tasks (r=0,77 and 0,60). With only 4 hours of training, rehabilitation professionals were able learn to teleoperate successfully TELEROBOT. However teleoperation performances remained significantly less efficient then those of an expert. Under the home task condition (navigating the home environment from one point to the other as fast as possible) this translated to completion time between 350 seconds (best performance) and 850 seconds (worse performance). Improvements in other usability aspects of the system will be needed to meet the requirements of in-home telerehabilitation.

A Remote Lab for Experiments with a Team of Mobile Robots

PubMed Central

Casini, Marco; Garulli, Andrea; Giannitrapani, Antonio; Vicino, Antonio

2014-01-01

In this paper, a remote lab for experimenting with a team of mobile robots is presented. Robots are built with the LEGO Mindstorms technology and user-defined control laws can be directly coded in the Matlab programming language and validated on the real system. The lab is versatile enough to be used for both teaching and research purposes. Students can easily go through a number of predefined mobile robotics experiences without having to worry about robot hardware or low-level programming languages. More advanced experiments can also be carried out by uploading custom controllers. The capability to have full control of the vehicles, together with the possibility to define arbitrarily complex environments through the definition of virtual obstacles, makes the proposed facility well suited to quickly test and compare different control laws in a real-world scenario. Moreover, the user can simulate the presence of different types of exteroceptive sensors on board of the robots or a specific communication architecture among the agents, so that decentralized control strategies and motion coordination algorithms can be easily implemented and tested. A number of possible applications and real experiments are presented in order to illustrate the main features of the proposed mobile robotics remote lab. PMID:25192316

A remote lab for experiments with a team of mobile robots.

PubMed

Casini, Marco; Garulli, Andrea; Giannitrapani, Antonio; Vicino, Antonio

2014-09-04

In this paper, a remote lab for experimenting with a team of mobile robots is presented. Robots are built with the LEGO Mindstorms technology and user-defined control laws can be directly coded in the Matlab programming language and validated on the real system. The lab is versatile enough to be used for both teaching and research purposes. Students can easily go through a number of predefined mobile robotics experiences without having to worry about robot hardware or low-level programming languages. More advanced experiments can also be carried out by uploading custom controllers. The capability to have full control of the vehicles, together with the possibility to define arbitrarily complex environments through the definition of virtual obstacles, makes the proposed facility well suited to quickly test and compare different control laws in a real-world scenario. Moreover, the user can simulate the presence of different types of exteroceptive sensors on board of the robots or a specific communication architecture among the agents, so that decentralized control strategies and motion coordination algorithms can be easily implemented and tested. A number of possible applications and real experiments are presented in order to illustrate the main features of the proposed mobile robotics remote lab.

Embedded mobile farm robot for identification of diseased plants

NASA Astrophysics Data System (ADS)

Sadistap, S. S.; Botre, B. A.; Pandit, Harshavardhan; Chandrasekhar; Rao, Adesh

2013-07-01

This paper presents the development of a mobile robot used in farms for identification of diseased plants. It puts forth two of the major aspects of robotics namely automated navigation and image processing. The robot navigates on the basis of the GPS (Global Positioning System) location and data obtained from IR (Infrared) sensors to avoid any obstacles in its path. It uses an image processing algorithm to differentiate between diseased and non-diseased plants. A robotic platform consisting of an ARM9 processor, motor drivers, robot mechanical assembly, camera and infrared sensors has been used. Mini2440 microcontroller has been used wherein Embedded linux OS (Operating System) is implemented.

A Simple Interface for 3D Position Estimation of a Mobile Robot with Single Camera.

PubMed

Chao, Chun-Tang; Chung, Ming-Hsuan; Chiou, Juing-Shian; Wang, Chi-Jo

2016-03-25

In recent years, there has been an increase in the number of mobile robots controlled by a smart phone or tablet. This paper proposes a visual control interface for a mobile robot with a single camera to easily control the robot actions and estimate the 3D position of a target. In this proposal, the mobile robot employed an Arduino Yun as the core processor and was remote-controlled by a tablet with an Android operating system. In addition, the robot was fitted with a three-axis robotic arm for grasping. Both the real-time control signal and video transmission are transmitted via Wi-Fi. We show that with a properly calibrated camera and the proposed prototype procedures, the users can click on a desired position or object on the touchscreen and estimate its 3D coordinates in the real world by simple analytic geometry instead of a complicated algorithm. The results of the measurement verification demonstrates that this approach has great potential for mobile robots.

Integrating Mobile Robotics and Vision with Undergraduate Computer Science

ERIC Educational Resources Information Center

Cielniak, G.; Bellotto, N.; Duckett, T.

2013-01-01

This paper describes the integration of robotics education into an undergraduate Computer Science curriculum. The proposed approach delivers mobile robotics as well as covering the closely related field of Computer Vision and is directly linked to the research conducted at the authors' institution. The paper describes the most relevant details of…

A Contest-Oriented Project for Learning Intelligent Mobile Robots

ERIC Educational Resources Information Center

Huang, Hsin-Hsiung; Su, Juing-Huei; Lee, Chyi-Shyong

2013-01-01

A contest-oriented project for undergraduate students to learn implementation skills and theories related to intelligent mobile robots is presented in this paper. The project, related to Micromouse, Robotrace (Robotrace is the title of Taiwanese and Japanese robot races), and line-maze contests was developed by the embedded control system research…

Design of a Teleoperated Needle Steering System for MRI-guided Prostate Interventions

PubMed Central

Seifabadi, Reza; Iordachita, Iulian; Fichtinger, Gabor

2013-01-01

Accurate needle placement plays a key role in success of prostate biopsy and brachytherapy. During percutaneous interventions, the prostate gland rotates and deforms which may cause significant target displacement. In these cases straight needle trajectory is not sufficient for precise targeting. Although needle spinning and fast insertion may be helpful, they do not entirely resolve the issue. We propose robot-assisted bevel-tip needle steering under MRI guidance as a potential solution to compensate for the target displacement. MRI is chosen for its superior soft tissue contrast in prostate imaging. Due to the confined workspace of the MRI scanner and the requirement for the clinician to be present inside the MRI room during the procedure, we designed a MRI-compatible 2-DOF haptic device to command the needle steering slave robot which operates inside the scanner. The needle steering slave robot was designed to be integrated with a previously developed pneumatically actuated transperineal robot for MRI-guided prostate needle placement. We describe design challenges and present the conceptual design of the master and slave robots and the associated controller. PMID:24649480

Space-time modeling using environmental constraints in a mobile robot system

NASA Technical Reports Server (NTRS)

Slack, Marc G.

1990-01-01

Grid-based models of a robot's local environment have been used by many researchers building mobile robot control systems. The attraction of grid-based models is their clear parallel between the internal model and the external world. However, the discrete nature of such representations does not match well with the continuous nature of actions and usually serves to limit the abilities of the robot. This work describes a spatial modeling system that extracts information from a grid-based representation to form a symbolic representation of the robot's local environment. The approach makes a separation between the representation provided by the sensing system and the representation used by the action system. Separation allows asynchronous operation between sensing and action in a mobile robot, as well as the generation of a more continuous representation upon which to base actions.

Efficient Control Law Simulation for Multiple Mobile Robots

DOE Office of Scientific and Technical Information (OSTI.GOV)

Driessen, B.J.; Feddema, J.T.; Kotulski, J.D.

1998-10-06

In this paper we consider the problem of simulating simple control laws involving large numbers of mobile robots. Such simulation can be computationally prohibitive if the number of robots is large enough, say 1 million, due to the 0(N2 ) cost of each time step. This work therefore uses hierarchical tree-based methods for calculating the control law. These tree-based approaches have O(NlogN) cost per time step, thus allowing for efficient simulation involving a large number of robots. For concreteness, a decentralized control law which involves only the distance and bearing to the closest neighbor robot will be considered. The timemore » to calculate the control law for each robot at each time step is demonstrated to be O(logN).« less

The mechanical design of a humanoid robot with flexible skin sensor for use in psychiatric therapy

NASA Astrophysics Data System (ADS)

Burns, Alec; Tadesse, Yonas

2014-03-01

In this paper, a humanoid robot is presented for ultimate use in the rehabilitation of children with mental disorders, such as autism. Creating affordable and efficient humanoids could assist the therapy in psychiatric disability by offering multimodal communication between the humanoid and humans. Yet, the humanoid development needs a seamless integration of artificial muscles, sensors, controllers and structures. We have designed a human-like robot that has 15 DOF, 580 mm tall and 925 mm arm span using a rapid prototyping system. The robot has a human-like appearance and movement. Flexible sensors around the arm and hands for safe human-robot interactions, and a two-wheel mobile platform for maneuverability are incorporated in the design. The robot has facial features for illustrating human-friendly behavior. The mechanical design of the robot and the characterization of the flexible sensors are presented. Comprehensive study on the upper body design, mobile base, actuators selection, electronics, and performance evaluation are included in this paper.