Markovian-Based Fault-Tolerant Control for Wheeled Mobile Manipulators

In this brief, we develop a methodology via Markovian control theory to evaluate fault- tolerant wheeled mobile manipulators. The transition rate uncertainties are allowed within an uncertainty domain. Since the velocity signals are generally not available and indirectly obtained from the measured positions, we are concerned with the output feedback H_∞ control based on a high-gain observer for wheeled mobile manipulators. The objective is to design a mode-dependent dynamic output feedback controller for wheeled mobile manipulators which guarantees not only the robust stochastic stability but also a prescribed disturbance attenuation level for the resulting closed-loop system, irrespective of the transition rate uncertainties. A sufficient condition for the solvability of this problem is obtained and the expression of the desired controller is given in terms of a set of linear matrix inequalities.