Robot control for robust stability with finite reachability time in the whole

A robot model incorporates possible discontinuous nonlinearities with unkno wn forms and values, unknown payload and unknown predictable external distu rbance variations, all in known bounds. A control algorithm is synthesized to guarantee the following: 1. Robust global both stability and attraction with finite reachability tim e of an appropriately chosen sliding set. 2. The robot motions reach, on the sliding set, a desired motion in a presp ecified finite time. 3. Robust both stability and global attraction with finite reachability tim e of the given robot desired motion. 4. A prespecified convergence quality of real motions to the desired motion , independently of the internal dynamics of the system and without oscillat ions, hence without chattering in the sliding mode. Robot control robustness means that the controller realizes the control wit hout using information about the real robot internal dynamics. All this is achieved by using the Lyapunov method in a new way combined with a sliding mode approach, but without a variation of the controller structure. The the oretical results are applied to a rotational 3-degree-of-freedom robot. The simulations well verify the robustness of the control algorithm and high q uality of robot motions with a prespecified reachability time. (C) 1999 Joh n Wiley & Sons, Inc.