Calibration of closed loop controllers for setting impedances in force-reflecting systems

This paper discusses a new method of impedance control that has been successfully implemented on the master robot of a teleoperation system. The method involves calibrating the robot to quantify the effect of adjustable controller parameters on the impedances along its different axes. The empirical equations relating end-effector impedance to the controller's feedback gains are obtained by performing system identification tests along individual axes of the robot. With these equations, online control of end-effector stiffness and damping is possible without having to monitor joint torques or solving complex algorithms. Hard contact conditions and compliant interfaces have been effectively demonstrated on a telemanipulation test-bed using appropriate combinations of stiffness and damping settings obtained by this method.

[1]  George C. Verghese,et al.  Design issues in 2-port network models of bilateral remote manipulation , 1989, Proceedings, 1989 International Conference on Robotics and Automation.

[2]  John Kenneth Salisbury,et al.  Haptic rendering: programming touch interaction with virtual objects , 1995, I3D '95.

[3]  Neville Hogan,et al.  Stable execution of contact tasks using impedance control , 1987, Proceedings. 1987 IEEE International Conference on Robotics and Automation.

[4]  Thomas H. Massie,et al.  The PHANToM Haptic Interface: A Device for Probing Virtual Objects , 1994 .

[5]  Blake Hannaford,et al.  Performance evaluation of a six-axis generalized force-reflecting teleoperator , 1991, IEEE Trans. Syst. Man Cybern..

[6]  Massimo Bergamasco,et al.  An arm exoskeleton system for teleoperation and virtual environments applications , 1994, Proceedings of the 1994 IEEE International Conference on Robotics and Automation.

[7]  N. Hogan,et al.  Impedance Control:An Approach to Manipulation,Parts I,II,III , 1985 .

[8]  Dale A. Lawrence Designing teleoperator architectures for transparency , 1992, Proceedings 1992 IEEE International Conference on Robotics and Automation.

[9]  Homayoon Kazerooni,et al.  The dynamics and control of a haptic interface device , 1994, IEEE Trans. Robotics Autom..

[10]  Massimo Bergamasco,et al.  Experimental approach to virtual surfaces exploration exploiting an arm exoskeleton as haptic interface , 1995, Other Conferences.

[11]  Blake Hannaford,et al.  A design framework for teleoperators with kinesthetic feedback , 1989, IEEE Trans. Robotics Autom..

[12]  Yury Stepanenko,et al.  New model reference impedance controller for telerobotics , 1993, Other Conferences.