Dynamic Output Feedback Fault-Tolerant Control for T-S Fuzzy Fractional-Order Systems Based on Improved Intermediate Observer

This paper investigates the problem of dynamic output feedback fault-tolerant control (DOF-FTC) for T-S fuzzy fractional-order systems (TSFFOSs) subject to multiple faults and mismatched disturbances. First, the system is preprocessed using augmentation and desingularization techniques. Then, by optimizing the structure of the traditional fractional-order intermediate observer, the joint estimation of states, faults and mismatched disturbances in the system is achieved. In particular, the estimation performance is significantly improved. More importantly, during the design of the observer, the reliance onH∞methods and decoupling methods for disturbance handling is eliminated. Furthermore, a novel DOF-FTC strategy is developed, which does not require state information. The designed controller can be adjusted online based on the estimation of faults and disturbances to ensure system stability. Finally, a permanent magnet synchronous motor model is employed to verify the effectiveness of the proposed method.