A contribution to minimum-time task-space path-following problem for redundant manipulators

摘要

The minimum-time path-following problem for non-redundant manipulator has already been analyzed and a number of efficient solution algorithms have been proposed. These algorithms can be applied also to redundant manipulators if the path is assigned in the joint space. If the path is assigned in the task space instead, how to exploit kinematic redundancy to reduce the execution time is still an open problem. In this paper it is proposed to follow a heuristic approach to choose between different solutions to the inverse kinematics problem that underlies the minimum-time path-following control problem. The aim is to obtain a joint-space path which configures the manipulator so as to improve acceleration/deceleration capabilities of the end-effector. This is obtained by penalizing the motion of joints with higher inertia-to-torque ratios. Numerical results are presented for an "easy-to-understand" three degree-of-freedom planar manipulator involved in two-dimensional paths.