Digital implementation of an observer-based controller for a rigid robot

We present a digital implementation of an observer-based controller, using a simple forward Euler discretization scheme, for a rigid robot. The observer used here is the one given in Busawon, Saif and Farza (1997) with a slight change in the gain so as to incorporate part of the nonlinearity. So doing, the high gain property of the observer is lessened to some extent. A comparison of the convergence is presented when this modified observer and a purely high gain observer is utilized. It is shown that the transient oscillations when using a purely high gain observer is considerably diminished by using the modified observer.