Research On Method Of Vehicle ATP Protection Curve For CTCS3Train Control System

This thesis is mainly to study the algorithm of on-board ATP overspeed protection curve and the method of selecting and setting its step size parameter. Research of on-board ATP system model is focused on ATP overspeed protection curve algorithm. Train overspeed protection curve is mainly worked out through the traction calculation on the basis of the step size. After previous years of research, traction calculation of ATP overspeed protection has been relatively mature, however, the study related to the step size for which is rarely. In the process of calculating on-board ATP protection curve, the calculation accuracy, convergence and timeliness are mutual restriction factors. Shortening the step length without limit can improve the calculation precision, but will reduce the convergence speed of function and the timeliness of data. Improving the convergence speed and timeliness without limit can reduce the calculation precision and brake accuracy. Therefore, this thesis studies on the step size parameter for on-board ATP protection curve calculation to find the right step parameter and step length, so that the calculated overspeed protection curve has high enough accuracy to ensure the safety of train operation. At the same time it also has the convergence speed and effectiveness to calculate the ATP protection curve within the specified time and control the train speed.On the base of analyzing the functional requirements of on-board ATP, this paper focuses on establishing dynamic mathematical model of ATP protection curve. By solving and simulating the braking curve model based on speed step, time step and distance step, the paper has analyzed the impact of the three step parameters on the calculation precision and function convergence. Results show that selecting time and distance as step size parameter, and setting appropriate step length, can effectively improve the calculation accuracy, and ensure that function has better convergence.Combined with the theoretical model of the on-board ATP overspeed protection, this paper establishes the train protection curve calculation model based on the combination step size parameter, mainly including calculation models of emergency braking curve, emergency brake trigger curve, conventional brake curve and conventional brake trigger curve. At the same time this paper gives the simulation implementation principle of the on-board ATP protection curve.Finally, the paper implements the simulation of the on-board ATP emergency braking curve and conventional braking curve. The simulation results show that the braking curve choosing time and distance as step length has higher accuracy than any braking curve choosing a single step. It verifies that the braking curve choosing combinational step length has high enough precision, and the function has very good convergence.