Robust Asynchronous Switching Fault-Tolerant Control for Multi-Phase Batch Processes With Time-Varying Delay

A robust asynchronous switching fault-tolerant control method is proposed to solve the problems of uncertainties, unknown disturbances, time-varying delays and partial actuator failures in multi-phase batch processes. Firstly, an asynchronous system composed of subsystems with different dimensions including stable and unstable case is established to describe such multi-phase batch processes more accurately. Then introducing the output tracking error, the established switching model of different dimensions is extended. On this basis, a robust asynchronous switching fault-tolerant control law is designed, which improves the system's ability to cope with negative factors such as actuator failure and can obtain greater adjustment freedom. Secondly, by using relevant theories and methods, the sufficient conditions in the form of linear matrix inequality (LMI) are given to ensure the exponential stability of the system and the asymptotic stability at each phase. By solving these LMIs conditions, the shortest running time under stable case, the longest running time under unstable case and the control law gain of each phase are obtained. Finally, the effectiveness and feasibility of the proposed method are verified with injection molding process.