Research On Asynchronous Brake Control Technology Of Ten-thousand-tons Heavy-haul Trains

Owing to the marshaling length and large freight volume, heavy-haul trains efficiently ease the tensions situation of freight. The present domestic heavy-haul trains are structured with dynamic distribution, and the synchronous braking control technology is used to implement the synchronous braking operation of the locomotives at different positions. Because the braking command transfer process has a delay and it has a poor adaptability for complex orbital environment, this technology leads to larger longitudinal coupling force during braking, which tends to hook buffer device direct damage and fatigue damage, and even the possible broken hook. Aiming at the problems, this dissertation puts forward a method of asynchronous brake control. Asynchronous brake control, based on the coupling force between the vehicle and track state information of locomotive, can generate the brake command of the train, which can largely alleviate the longitudinal coupling force and ensure the safety of train.According to the power distribution structure of heavy-haul trains, and the actual operation characteristics, this dissertation figures out the main functions and the structure of asynchronous brake control system. Based on the structure, the asynchronous brake control strategy and asynchronous brake controller modeling technologies have been further studied, and the asynchronous brake control system simulation have been implemented.Firstly, on the basis of analyzing the heavy-haul trains braking process, the feasibility of the asynchronous brake control has been studied theoretically, and the framework of the asynchronous brake control system has been established and the functional requirements of the system has been analyzed. According to the heavy-haul trains braking characteristics and the actual situation of the Daqin railway line, the asynchronous brake control strategy has been designed, which can improve the adaptability of train in varietious situations.Secondly, in order to make the fuzzy neural network more suitable for the modeling of heavy-haul trains braking controller, the typical five layer fuzzy neural network is improved to a four layer fuzzy neural network, and the learning algorithm has been studied. Then the asynchronous brake controller model based on the structure has been established. After analyzing the input and output, using clustering algorithm to generate fuzzy rules and selecting the membership function, the structure model of asynchronous brake controller has been established. The validity of the model has been verified by the corresponding simulation test.Finally, based on the field data of heavy-haul combined trains braking process from the Daqin line, the heavy-haul trains asynchronous brake control simulation system has been established, and all the functions of heavy-haul trains asynchronous brake system has been simulated. The contrast on three indexes of simulation results, which are longitudinal coupling force distribution, average coupling force and maximum coupling force, is made between asynchronous and synchronous braking mode in four conditions of common brake, controller faults, short-time communication interruptionang and parking brake. As a matter of fact the superiority of the asynchronous braking has been validated. The results of this study can provide theoretical basis and technical support for the application of asynchronous braking mode.