On the optimal control of robotic manipulators with actuator and end-effector constraints

Abstract

The motion of current industrial manipulators is typically controlled so that tasks are not done in a minimum time optimal manner. The result is substantially lower productivity than that potentially possible. Recently a computationally efficient algorithm has been developed to find the true minimum time optimal motion for a manipulator moving along a specified path in space that uses both the full nonlinear dynamic character of the manipulator and the constraints imposed by its actuators. A Computer Aided Design (CAD) implementation of the algorithm called OPTARM is described which can treat practically general six degree-of-freedom manipulators. Examples are presented which show OPTARM to be a useful design tool for manipulators, their tasks and work places. The algorithm is extended in OPTARM to include the constraints imposed by manipulator payloads and end-effectors.