A speed trajectory optimization model for rail vehicles using mixed integer linear programming

With the increasing of energy demand, energy conservation is becoming more important in rail transportation. In order to minimize the energy consumption for the transportation system, the speed trajectory optimization and regenerative braking method are applied to improve the energy efficiency in rail vehicle traction system. In this paper, a mathematic model is proposed to locate the optimal trajectory with the given initial speed and braking distance using mixed integer linear programming method. This model could deal with the scenarios under practical constraints such as journey time, route altitude and speed limits. Thus, the model proposed in this paper is able to locate the speed trajectory with minimum energy consumption for practical train operation. Compared with previous research, the previous study could merely deal with monotonous trajectory, but the model in this paper has no such constraints and it able to deal with more complicated application scenarios. Model using mixed integer linear programming method is robust and adaptive in managing constraints. In future work, more constraints such as battery characteristic and motor efficiency will be considered in the model.