ON THE STABILITY OF THE HYBRID-DAMPED RESOLVED-ACCELERATION CONTROL

This paper points out that the stability analysis of the hybrid-damped resolved-acceleration control in our earlier work is incomplete, sinc e the stability was concluded directly from the fact that the joint ve locities come to rest as time approaches infinity. A similar incomplet e technique was also used in the work of Wampler and Leifer to prove t he stability of a damped least-squares resolved-acceleration control s cheme. In this paper, we use LaSalle's invariance principle rigorously to show that the solution trajectory of the hybrid-damped resolved-ac celeration control will eventually come to the target without steady-s tate error or will stay at a kinematic singular point with some steady -state error. Discussions on the case of staying at a singular point a re also given. (C) 1998 John Wiley & Sons, Inc.