Research on energy-saving and punctuality-oriented train operation strategy based on multi-objective dynamic programming

To improve the operation of existing trains that inadequately achieve energy saving and punctuality, this paper proposes a multi-objective dynamic programming-based train operation strategy oriented towards energy saving and punctuality (MDP-EP), through analyzing the coupling mechanism between energy-saving and punctuality-oriented operation strategies. First, the train operation route was divided into several segments based on track feature information, considering the cumulative characteristics of train operation in terms of energy consumption and running time. This approach aimed to improve adaptability to variations in track feature information. Next, a speed domain reachable set and traction/braking force domain reachable set were generated based on kinematic and dynamic constraints, respectively. This step aimed to improve adaptability to constraints arising from the complex control characteristics of trains, based on state and control constraints. Following this, a minimum energy consumption-optimal running time objective function was developed, leveraging the coupling mechanism of energy saving and punctuality targets. A multi-objective dynamic programming method was then devised for iterative solutions. The energy-saving and punctuality effects of the MDP-EP strategy were verified in MATLAB-based simulation environments and experimental environments for applications in high-speed train operation. The results show the effective energy-saving performance of the proposed MDP-EP strategy in high-speed train operation while guaranteeing the running time. Specifically, MDP-EP increased the energy-saving index by 10%, compared with punctuality-oriented programming.