Simulation Research Of Algorithms For Freight Train Assistant Driving

At the present stage, the operation control quality of freight trains in our country mainly depends on the control levels of individual drivers. Due to the lack of effective driving guidance, in most cases, drivers can only rely on their own experiences to drive properly and the energy-efficiency of their driving is hard to guarantee. The operation schematic diagrams and cue cards from the operation departments can only help drivers have a general idea of how to drive on the route, which have a lot of limits. Therefore, to assist drivers to drive well through providing driving guidance speed profile by train driver assistant systems is an effective solution.For freight trains, the main goal of optimized operation is to save energy consumption as much as possible on the basis of operation safety, steadiness and punctuality. In this thesis, based on the actual demand of freight train assistant driving, the methods of theoretical analysis and software simulation are adopted to study the optimization of train driving strategies and the main research contents are as follows.Firstly, according to basic principles of train traction calculation, the force analysis of the operating train is carried out and the model for calculating train operation speed and time is established. Secondly, the mathematical model for train energy-saving operation is set up and then the train energy-saving optimization problem is expressed as an optimal control problem. The minimization of traction energy consumption is set as the optimization goal. By using Pontryagin’s maximum principle, the energy-efficient driving strategies and the conversion principle of operating modes are analyzed and summarized, and the numerical algorithm for calculating the sequence of energy-efficient operating modes is proposed. Thirdly, the basic principles of train control are introduced, and the train driving strategies at different operation stages for safety and steadiness are analyzed and summarized; through analyzing the influence of block signal on train operation, the basis for setting and adjusting interval segmented target speed is obtained; according to the energy-efficient driving strategies and constraints of train safety and steadiness, the algorithm for creating driving guidance speed profile is proposed.Finally, a freight train running simulation software is developed based on Visual C++ development environment and the algorithm for creating driving guidance speed profile is designed and implemented. Simulations of freight trains powered by HXD electric locomotives are undertaken and the correctness and effectiveness of the algorithm for creating and adjusting driving guidance speed profile are verified.