Optimal Design of Safe Braking Curve of On-board ATP System in High-speed Train

ATP is a system to ensure safe and efficient running of high speed train. The design of ATP safe braking curve is one of the key technologies of the on-board ATP system. Because of the limited calculation speed and memory space of the onboard computer, the safe braking curve usually adopts simplified calculation models, among which the method based on UIC544-1 standard is a typical one. The calculation of deceleration in the method based on UIC544-1 standard is greatly simplified by dividing at most six speed ladders, within which the deceleration is considered as constant. But it usually comes out the ATP safe braking curve with bad performance in efficiency and great fluctuation in running safety because of current fixed-interval division of speed ladder. Based on the calculation principle of UIC544-1 standard, this paper developed a multi-objective model to optimize the division of speed ladder in the calculation model at the target of minimizing the loss of efficiency and the fluctuation of safety margin. General rules to design division of speed ladder in UIC544-1 ladder were presented by case studies with different slope and braking performance. In comparison with the current ATP safe braking curve, the results show that the loss of efficiency and the fluctuation in safety margin are reduced by 5.66% and 2.83%, respectively. Extensive studies confirm the adaptability of the solution to the fluctuation of the slope of the track and the braking performance in a certain range. © 2018, Department of Journal of the China Railway Society. All right reserved.