| Abstract: | The movement of redundant manipulator joints that does not cause any end-effector motion is referred to as its self motion. Control schemes for redundant manipulators utilize its self motion to optimize a performance criterion. Thus, commanded joint motion at each sampling step is the sum of the minimum joint motion required for the desired end-effector motion and the self motion. However, the amount of self motion is limited by the bounds on actuator velocities, which are limited by the actuator torque bounds. A scheme is presented to determine the magnitude of self motion, the direction of which is determined by a gradient projection scheme. Implementation of this scheme on a Motorola 68020 VMEbus-based controller of a seven-degree-of-freedom manipulator is described. |
