ABSTRACT
It is both theoretically and practically important to investigate the problem of accommodating intermittent actuator failures in controlling uncertain systems. However, the number of results available in developing adaptive controllers to address this problem is very limited. In this chapter, a new adaptive failure compensation control scheme is proposed for parametric strict feedback nonlinear systems. The techniques of nonlinear damping and parameter projection are employed in the design of controllers and parameter estimators, respectively. It is proved that the boundedness of all closed-loop signals can still be ensured in the case with infinite number of failures, provided that the time interval between two successive changes of failure pattern is bounded below by an arbitrary positive number. The performance of the tracking error in the mean square sense with respect to the frequency of failure pattern changes is also established. Moreover, asymptotic tracking can be achieved when the number of failures is finite.
