Robust Stochastic Control for High-Speed Trains With Nonlinearity, Parametric Uncertainty, and Multiple Time-Varying Delays

In this paper, a novel delay-dependent robust H_\infty control criterion for the velocity tracking control of high-speed trains is developed based on a multi-particle model and Lyapunov stability theory. The dynamic model of high-speed trains is proposed with consideration of the nonlinearity of aerodynamic drag, stochastic property of the measuring signals, uncertainties of train mass, resistance and stiffness of the couplers, multiple time-varying state delays, and input delays caused by the transmission process. Numerical simulations are carried out to verify the effectiveness and robustness of the proposed controllers, while the weights of delays are varying, and explore the influences of actuation power distribution on the velocity tracking performance and driving smoothness. Moreover, some useful results are obtained from the comparison between the proposed robust H_{\infty } controller and an existing robust adaptive controller, which can also deal with parameter uncertainties and nonlinearity.