Fault Estimation and Tolerant Control of a Class of Nonlinear Systems and Its Application in High-Speed Trains

This brief investigates the problem of fault estimation and tolerant control for a class of large-scale systems composed of multiple subsystems of second-order nonlinear dynamics. In particular, there is no growth rate condition on system nonlinearities or bounded constraints on faults or their derivatives. Technically, a novel representation of a fault based on its structural information is used for the problem formulation, which facilitates the design of a distributed fault estimation observer (DFEO) with the fault estimation error globally asymptotically approaching zero. Based on the observer, a distributed fault tolerance controller (DFTC) can be designed for asymptotical reference trajectory tracking. The overall observer and controller design scheme are applied to high-speed trains in the presence of actuator faults, which illustrates the effectiveness of the scheme in a practical application.