Fault-Tolerant Control and Disturbance Rejection for Polynomial Fault Systems Under Actuator Saturation

Abstract

This paper addresses the fault-tolerant control problem for polynomial fault systems under actuator saturation. The fault is modeled as a polynomial function, while the unknown disturbance is generated by a known external system. An observer is used to simultaneously estimate the disturbance, fault, and system state. Furthermore, since saturation in real-world systems is not solely due to physical limitations of components, an anti-saturation compensator is introduced to compensate for the input and to address the coupling between the fault and saturation. An $L_2$ gain is used to limit the energy transfer from the saturation error to the system, ultimately achieving anti-saturation fault-tolerant control. Finally, two practical examples validate the effectiveness of the proposed method.