Time-Space-Based Virtual Coupling High-Speed Train Separation Model and Trajectory Planning

The Virtual coupling is proposed as a blocking mode to address the increasing demand for railway transport capacity, which takes operation efficiency further improve by separating trains with a relative braking distance. Nevertheless, an insufficient protection for complete avoidance safety risks in time with limited and fluctuate spacing separation between consecutive trains is introduced. A time-space occupancy band model is established to hold a safety protection in time-space dimension and assess the transport capacity for train operation under virtual coupling. In addition, a train trajectory planning method aimed at improvement of transport capacity, is proposed as a two-step program consisting of train followed operation trajectory planning based on Markov Decision Process and a trajectory multi-objective optimization for train convoy. In order to meet the requirement of the train trajectory dynamic adjustment under disturbance, an approach based on trajectory strategy set is designed by two stages to consider objectives of safety and punctuality. Based on the field data from the Wuhan-Guangzhou high-speed railway line, numerical experiments are conducted to validate the applicability of the proposed model and method. A comparative analysis of the track resource occupancy for several application condition under virtual coupling, and signaling systems is provided. The results indicate that the effective performance of proposed method in terms of trains separation and track resource occupancy, and show that virtual coupling is a more satisfactory blocking mode that could provide a higher track resource utilization while operation conditions are taken into account.