A gain scheduling approach in decentralized manipulator control using discretized equivalent joint models

Abstract

A decentralized digital trajectory controller for manipulator arms based on a computer torque approach has been developed and tested. A discretized equivalent model of the continuous manipulator system has been derived and used to design digital feedback and compensation filters for this purpose. Time schedules of parameters of these filters were generated offline when the desired trajectory was planned. A stability analysis has been carried out to determine the effect of deviations of the actual trajectory and model parameters from their normal values on the system stability, and the bounds on these deviations within which the control scheme is stable. The control approach has been tested using a hierarchical multiprocessor architecture and a six-joint PUMA 560 robot arm. The performance of the controller is encouraging and compares favorably with the experimental performance of other tested controllers.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>