Distributed Fault-Tolerant Control of Virtually and Physically Interconnected Systems with Application to High-Speed Trains under Traction/Braking Failures

This paper investigates the tracking control problem of dynamic systems consisting of physically connected subsystems with virtual connections through local communication, where unknown unidentical nonlinearities, time-varying yet undetectable actuation faults, and varying actuation authorities are involved. The local communication nature and the physical uncertain interactions among the subsystems, together with the unpredictable actuation failures and control authority variation, make the underlying problem nontrivial, calling for a control solution that is not only decentralized (distributed) but also adaptive and fault tolerant. In this paper, with the aid of the concepts of generalized parameter estimation error and virtual regrouping, a distributed and fault-tolerant control design approach is presented by using local (neighboring) information exchange only. This method is applied to develop tracking and braking control schemes for high-speed trains subject to traction and braking failures. The proposed distributed control is capable of simultaneously coping with the physical interactions among the subsystems, compensating the uncertain control gains, and accommodating the undetectable actuation faults, as authenticated and verified by theoretical analysis and numerical simulations.