Design and construction of a portable force-reflecting manual controller for teleoperation systems

A man-machine system called teleoperator system has been developed to work in hazardous environments such as nuclear reactor plants. Force reflection is a type of force feedback in which forces experienced by the remote manipulator are fed back to the manual controller. In a force-reflecting teleoperation system, the operator uses the manual controller to direct the remote manipulator and receives visual information from a video image and/or graphical animation on the computer screen. This thesis presents the design of a portable Force-Reflecting Manual Controller (FRMC) for the teleoperation of tasks such as hazardous material handling, waste cleanup, and space-related operations. The work consists of the design and construction of a prototype 1-Degree-of-Freedom (DOF) FRMC, the development of the Graphical User Interface (GUI), and system integration. Two control strategies - PID and fuzzy logic controllers are developed and experimentally tested. The system response of each is analyzed and evaluated. In addition, the concept of a telesensation system is introduced, and a variety of design alternatives of a 3-DOF FRMC are proposed for future development

Development and validation of metrics to evaluate robotics operator performance.

This dissertation sought to develop and validate objective performance metrics for RMS operators to facilitate operator screening, provide training feedback, and examine performance changes over time. Preliminary investigation identified smooth hand controller inputs (ramping) and multi-axis commanding as skills that are critical to the safe, effective operation of the RMS robotic arm. Theoretical models of expert performance were developed that helped to identify critical aspects of these skills. Performance metrics were selected that quantified the differences observed during comparisons of actual operator performance with the theoretical models. Observed control strategies were discussed from a human factors standpoint.Validation of the metrics was achieved in an empirical study during which twelve novice operators performed a series of targeted movement tasks designed to evaluate ramping performance and the use of multi-axis control. Ramping performance was assessed by examining velocities and accelerations, R-square values (representing smoothness of the commanded inputs), completion times, and distances traveled during the ramp-in, travel, ramp-out, and correction phases of the task. Multi-axis control was assessed by examining percentages of control usage (single, dual, and triple-axis), lag times, completion times, accelerations, and correction times. MANOVA results indicated that ramping performance was significantly affected by movement distance (F 7,5 = 333.02, p < .0001) and operator ( F77,103.32 = 6.86, p < .0001), and multi-axis performance varied significantly due to task distance ratios ( F4,8 = 22.63, p = .0002), replicate ( F4,8 = 35.87, p < .0001), and operator (F44,1727.4 = 19.85, p < .0001). A select subset of the metrics successfully achieved a reasonable classification of RMS operator performance.Remote Manipulator Systems (RMS) aboard the International Space Station and the Space Shuttle assist in payload management, crew movement, retrieval of objects from space, and station construction. Generic Robotics Training (GRT) uses the Basic Operational Robotics Instructional System (BORIS) graphics simulator to teach basic robotics concepts and skills that are transferable to any of the on-orbit RMS systems. Currently, operator competency is assessed on a five-point scale by an "expert" observer. There is a need for quantitative performance metrics that would achieve an objective, reliable, and sensitive evaluation of RMS operator capabilities

Augmented Reality Navigation Interfaces Improve Human Performance In End-Effector Controlled Telerobotics

On the International Space Station (ISS) and space shuttles, the National Aeronautics and Space Administration (NASA) has used robotic manipulators extensively to perform payload handling and maintenance tasks. Teleoperating robots require expert skills and optimal performance is crucial to mission completion and crew safety. Degradation in performance is observed when manual control is mediated through remote camera views, resulting in poor end-effector navigation quality and extended task completion times. This thesis explores the application of three-dimensional augmented reality (AR) interfaces specifically designed to improve human performance during end-effector controlled teleoperations. A modular telerobotic test bed was developed for this purpose and several experiments were conducted. In the first experiment, the effect of camera placement on end-effector manipulation performance was evaluated. Results show that increasing misalignment between the displayed end-effector and hand-controller axes (display-control misalignments) increases the time required to process a movement input. Simple AR movement cues were found to mitigate the adverse effects of camera-based teleoperation and made performance invariant to misalignment. Applying these movement cues to payload transport tasks correspondingly demonstrated improvements in free-space navigation quality over conventional end-effector control using multiple cameras. Collision-free teleoperations are also a critical requirement in space. To help the operators guide robots safely, a novel method was evaluated. Navigation plans computed by a planning agent are presented to the operator sequentially through an AR interface. The plans in combination with the interface allow the operator to guide the end-effector through collision-free regions in the remote environment safely. Experimental results show significant benefits in control performance including reduced path deviation and travel distance. Overall, the results show that AR interfaces can improve performance during manual control of remote robots and have tremendous potential in current and future teleoperated space robotic systems; as well as in contemporary military and surgical applications