Online Energy-efficient Control of Urban Rail Train Operation Based on Switching Time Optimization

Traditional energy-saving driving strategy is to make the train track an off-line optimal speed curve in actual operation. Due to the disturbance in the daily operation of the train, the off-line optimal speed curve is no longer applicable to real situations. This paper studies the online energy-efficient control of single urban rail train operation within a fixed running time between two adjacent stations. A switched-mode system model is proposed to describe the inter-station running characteristics of a train. Based on this model, an optimization problem to minimize the energy consumption of the train is proposed. The optimal switching time can be calculated online by using a switching time optimization algorithm. Since the state transition matrix between adjacent switching times can be calculated offline, in this method, the computation cost is greatly reduced by allocating the operation with the largest proportion to the cost function and its derivative. Finally, the effectiveness of the proposed method is verified by simulations using the measured data of urban railway train.