A Stochastic Reachable Set Based Train Following Safety Protection Method for “Soft-Wall” Moving Block Train Control System

Although moving block mode “hard-wall” safety protection principle adopted by the existing urban rail train control system has shortened the following interval of trains to a certain extent, it fails to meet the operational demand during peak hours. In this paper, a train following safety protection method based on stochastic reachable set is proposed, which upgrades the safety protection criterion from position non-overlapping in spatial dimension to trajectory non-overlapping in space-time dimension. Firstly, the whole process predicted trajectory of the preceding train and the safety braking trajectory of the following train are represented. Secondly, the efficient calculation model of collision probability is established by combining the probability distribution functions of the preceding train and the following train. Then, the corresponding safety protection curve is generated according to the safety verification results of the urban rail train. Finally, the method is verified by using the data of Beijing Metro Line 11. The experimental results show that, compared with the short-time protection, the method proposed in this paper can extend the reverse calculation starting point of the safety protection curve for following train and shorten the following interval on the basis of collision avoidance, which proves the necessity and applicability of this method.