Self-tuning fault-tolerant digital PID controller for MIMO analogue systems with partial actuator and system component failures

A new methodology is presented to synthesize a digitally redesigned, active, self-tuning, fault-tolerant proportional - integral - derivative (PID) controller for multi-input - multi-output (MIMO) analogue systems to against partial actuator and system component failures. The fault-tolerant control (FTC) scheme possesses the ability to accommodate for system failures automatically and maintains the acceptable overall system performance in the event of partial actuator and system component failures. The theoretically well-designed analogue PID controller is refined using the continuous-time linear-quadratic regulator approach to have the high-gain property. Then, a predication-based digital redesign technique is utilized to discretize the cascaded MIMO analogue PID controller for finding a low-gain digital PID controller. Besides, a self-tuning FTC scheme with a modified Kalman filter algorithm is proposed, which is not only for the control system design but also for the faulty system recovery. The designed scheme can easily be implemented using digital processors. An illustrative example is presented to demonstrate the effectiveness of the proposed methodology.