Reconfigurable control system design for fault diagnosis and accommodation

The online fault tolerant control problem for dynamic systems under unanticipated failures is investigated from a realistic point of view without any specific assumption on type of system dynamical structure or failure scenarios. The necessary and sufficient conditions for system online stability under catastrophic failures have been derived using the discrete-time Lyapunov stability theory. Based upon existing control theory and modern intelligent techniques, an online fault accommodation control strategy is proposed to deal with the desired trajectory-tracking problems for systems suffering from various unknown and unanticipated catastrophic component failures. Through the online estimator, effective control signals to accommodate the dynamic failures can be computed using only the partially available information of the faults. To investigate the feasibility of using the developed technique for unanticipated fault accommodation in real hardware under the real-time environment, an online fault tolerant control test bed has been constructed to validate the proposed technology. Both online simulations and the real-time experiment show encouraging results and promising futures of online real-time fault tolerant control based solely upon insufficient information of the system dynamics and the failure modes.