Robust Fault Tolerant Control Strategy for a Class of Nonlinear Uncertain Systems

This paper describes a fault tolerant controller for a class of nonlinear systems. The systems considered here are nonlinear with model uncertainty and are subject to some specific faults due to loading and temperature variations, plus sensor faults. To achieve this goal, passive and active fault tolerant strategies are merged together to provide a robust algorithm against both internal and external factors. The proposed controller detects the occurrence of the fault in the closed loop system and switches itself between a control strategy designed for nominal operation and a robust control strategy designed for faulty conditions. The switching function serves as the fault indicator as well. The proposed approach is applied to the fault tolerant control of induction motors. Simulation experiments in terms of speed and flux responses show the effectiveness of the proposed approach