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 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.