MINIMUM-TIME POINTING CONTROL OF A 2-LINK MANIPULATOR

In this paper, we investigate minimum-time pointing control for the end effector of a planar, two-link manipulator. Minimum-time pointing control is a new area of research for multilink manipulators and can be applied to rapid retargeting control of a multibody spacecraft. Many researchers have investigated the minimum- time control problems of industrial robots; their results are limited, however, to moving the end effector of the manipulator to reach a particular point, to travel a given distance, or to follow a predetermined path. We consider the minimum-time control problem of aligning the second link of the two-link manipulator with a given target point. A numerical method, called the minimizing-boundary-condition method, is used to determine optimal solutions for the two-point boundary-value problem associated with first-order necessary conditions. Minimum-time solutions for different models of pointing systems are compared. The results show that a two-link manipulator with two degrees of freedom performs better than a conventional one-link system for minimum-time pointing. © 1990 American Institute of Aeronautics and Astronautics, Inc., All rights reserved.