earticle

영어

This paper investigates the tracking control problem of high-speed trains, and a direct robust adaptive control strategy is designed to deal with the uncertainties and time-varying properties occurring in the train dynamics. The longitudinal dynamics of the train is a typical uncertain nonlinear presentation, whose parameters, especially the coefficients of the resistance cannot be acquired precisely and varying due to the complexity running conditions, and the impacts of these uncertainties are becoming even more serious as the speed increases. Although adaptive algorithm can improve a controller performance with parameterized uncertainties where the plant parameters are unknown but constant for all time, the stability properties can no longer be guaranteed when the plant parameters are varying with time even the speed of the variations are sufficiently small. In this paper, a traditional adaptive controller is designed based on the time-invariant assumption, and then, a kind of robust adaptive law is designed to improve the robustness when the plant parameters are varying slowly with time. Both the rigorous analysis and the simulation results are all verified the effectiveness of the proposed control scheme.