Fault tolerant control for plug-and-play interconnected nonlinear systems

This paper considers interconnected nonlinear systems with on-line plugging/unplugging of subsystems that are modeled by state-varying and mode-varying switched systems. A modularized method is proposed to design each subsystem׳s decentralized control law, which together with a new condition on time intervals of plugging/unplugging lead to the stability of the interconnected system. Three plug-and-play based fault tolerant control algorithms are further provided in the presence of coupling faults. The new result allows for the plugging/unplugging without reconfiguring any subsystem׳s control law and without taking any action on the faulty subsystems. An example of coupled pendulums is taken to illustrate the theoretical results.