Composite Disturbance-Observer-Based Control and H Control for High Speed Trains with Actuator Faults

To guarantee the position and velocity tracking performance of high speed trains (HSTs) with actuator faults, a composite control algorithm consisting of the disturbance-observer-based control (DOBC) and H control is proposed. Based on the multiple point-mass model, the dynamics of HSTs is established by a cascade of carriages which are connected by flexible couplers, during the procedure of which, the running resistance, actuator faults and multiple disturbances are taken into account. The multiple disturbances are composed of two parts, one of which is the ramp resistance due to the track slope, the other is unknown gusts which can be modeled as a harmonic disturbance with time-varying frequency. The unknown gusts is estimated and rejected via the DOBC methodology, meanwhile, the running resistance and the ramp resistance are attenuated by the H control methodology. According to the Lyapunov stability analysis and LMI-based algorithms, main results are derived such that the closed-loop system is asymptotically stable and the desired performance can be guaranteed. Compared with the numeral simulation results with the single H control method, it is demonstrated that the proposed control methodology is more effective and the system has a higher precision of position and velocity tracking.