Model-independent solution for active contact force control of pantographs in high-speed trains

In this work we present a high-gain observer based saturation control scheme for actively regulating the contact force to a bounded time-varying reference signal with a constant limit. It is shown that the resultant control scheme is largely model-independent with simple structure and inexpensive computation, yet effective in dealing with system modeling uncertainties and nonlinearities. High quality current collection characterized by a continuous smooth contact between the pantograph and the overhead contact wire is achieved with the proposed methods, as confirmed by formative theoretical analysis and numerical simulations.