“…In particular, one driving strategy, which considers all possible operations including acceleration, cruising, coasting and braking, has been comprehensively adopted in the ATO system [4], [21], [34], [35], and it helps to explore the flexibility and superiority of different combinations of train operations. As stated in [27], [35], based on Pontryagin's maximum principle (PMP), if the train is aimed to reach the destination as quickly as possible, the train is supposed to reach the maximum allowable speed first with full acceleration and keep the maximum speed (cruising) until the final braking point. Then the full braking is performed to stop the train.…”