AN INVERSE DYNAMICS CONTROL STRATEGY FOR TIP POSITION TRACKING OF FLEXIBLE MULTILINK MANIPULATORS

In this article, we present an inverse dynamics control strategy to ac hieve small tracking errors for a class of multi-link structurally fle xible manipulators. This is done by defining new outputs near the end points of the arms as well as by augmenting the control inputs by term s that ensure stable operation of the closed loop system under specifi c conditions. The controller is designed in a two-step process. First, a new output is defined such that the zero dynamics of the original s ystem are stabilized. Next, to ensure stable asymptotic tracking, the control input is modified such that stable asymptotic tracking of the new output or approximate tracking of the actual output may be achieve d. This is illustrated for the case of single- and two-link flexible m anipulators. (C) 1997 John Wiley & Sons, Inc.