Robust Fault-Tolerant Control Based on Set-Membership Estimation and Tube MPC

A robust fault-tolerant control method based on set-membership estimation and tube model predictive control (MPC) is proposed for the constrained linear systems subject to unknown disturbance and noise. Firstly, an augmented observer is used to estimate state and fault simultaneously. A fault-tolerant controller is proposed based on the state and fault estimation. And the estimation and feedback errors are bounded using set-membership estimation method. Then, the obtained error sets are used to design robust output feedback tube MPC strategy. In order to make the estimation error robust against disturbance and noise, the observer gain is designed based on $L_{\infty }$ method. Finally, the effectiveness and real-time performance of the proposed method is verified by a hardware-in-the-loop (HIL) test, which shows its potential application value in aeroengine control systems. Note to Practitioners—Many industrial systems for instance the aircraft and aeroengine control systems have high safety requirements. Fault-tolerant control (FTC) especially the active fault-tolerant (AFTC) is an effective way to improve the system security. In addition, the industrial control systems are usually subject to input and state constraints. Therefore, FTC method based on MPC has received increasing attention for the constrained systems especially the aerospace systems. However, how to deal with the model uncertainties including disturbance and noise is an important problem for FTC method based on MPC, which has not be investigated sufficiently. In this paper, we propose a robust fault-tolerant control method based on set-membership estimation and tube MPC for the constrained systems subject to unknown disturbance and noise. Based on the proposed method, the actual state can be guaranteed to satisfy the constraints while the system is subject to unknown disturbance, noise and actuator fault. The set-membership estimation method is introduced to reduce the computational burden of obtaining robust error sets for tube MPC. Moreover, by using the properties of Pontryagin difference and support function of zonotopes, the computational burden of calculating the tube MPC constraints is further reduced. The hardware-in-loop test of an aeroengine model shows the effectiveness of the proposed method and its potential application in aeronautical engineering.