Adaptive output feedback controller design for a class of uncertain nonlinear systems with actuator failures

In this paper, we aim to design adaptive output feedback controllers for a class of uncertain nonlinear multiple-input single-output (MISO) systems in the presence of stuck type actuator failures. The class of MISO system has a characteristic that the relative degrees with respect to each of the inputs are not necessarily the same. We first design a pre-filter for each input and then derive the state space representation of a newly constructed plant. The design of control variable will be provided by making certain modifications on traditional backstepping technique. It will be shown that with our proposed scheme, the effects due to actuator failures can be compensated and global boundedness of the closed-loop signals is still ensured. Further, the system output can asymptotically track a given reference signal.