Low-Complexity Fault-Tolerant Prescribed Performance Control of Unknown Nonlinear Systems With Deferred Actuator Replacement

This article is focused on the problem of prescribed performance control (PPC) for the strict-feedback systems under actuator failures with dynamic redundancies and deferred actuator replacement. It is concentrated on the cases where both the multiplicative nonlinearities and the additive nonlinearities of the plant are unknown and the fault-tolerant control (FTC) algorithm is as simple as possible. They render the existing solutions infeasible. In this article, we develop a low-complexity fault-tolerant PPC (FTPPC) approach, which is made up of a nominal controller, a fault detection module, and a reconfigurable controller. It ensures reference tracking with the predetermined speed and accuracy during the fault-free case and recovers the predefined performance after the deferred actuator replacement. The controller does not rely on the specific knowledge about the system dynamics, the disturbances, or the time profile and bound of the actuator failures. Moreover, it obviates the needs for parameter identification, function approximation, command filtering, and disturbance estimation. A comparative simulation on a jet engine compressor is carried out to demonstrate the above theoretical findings.