Smart construction for urban rail transit based on energy-efficient bi-directional vertical alignment optimisation

Due to the extensive use of urban rail transit systems in modern cities, the energy consumption of it rises significantly. To help reduce the energy consumption from the planning stage, the paper proposes a linear model to concurrently optimise the vertical alignment and bi-directional train speed profiles based on Mixed Integer Linear Programming (MILP), taking into account the regenerative energy. The paper investigates the scenarios with same station elevation and different station elevation, which clearly illustrates that the optimisation on vertical alignment can reduce net energy consumption by 39.7 % when compared to the reference scenario with vertical alignment not being optimised.