Research On Optimal Braking Process Control Of Heavy-haul Train On Long Steep Down Grade

Heavy-haul transportation and high-speed transportation are two important signs of railway modernization.The development of heavy-haul railway transportation has attracted the attention of many countries in the world and has become an internationally recognized direction for the development of railway freight transportation.The heavy-haul train is a complex electromechanical system with high nonlinearity and large inertia.Meanwhile,its driving route is very long and complex.There are many random states in the operation of heavy-haul train on the long steep grade.Therefore,the operation of heavy-haul train is much more complicated than ordinary train.In this paper,aiming at the longitudinal impulse of heavy-haul train caused by the running brake delay,a better braking control strategy is proposed and the target running curve is generated and the implicit generalized predictive control method is used to realize speed tracking control of the train.The main contents are as follows:1.The safe operation of heavy-haul train running on the long steep grade is affected by the condition of the line and the performance of the train.On the long steep grade,circulating air brakes are required to control the train running speed,which requires reasonable mastery of train braking and release.Firstly,the actual line information of the Daqin line and the performance parameters of the HXD1 heavy-haul train are collected and combined with the excellent driver experience of driving.Then,a better braking control strategy is proposed in multiple constraints such as line speed limit and train performance;The reduction of longitudinal impulse during train operation and the improvement of train stationarity verify the effectiveness of the control strategy.Finally,based on the control strategy,target speed curve on the long steep grade is generated.2.The operation process of heavy-haul trains is nonlinear,which is also required for the modeling and optimization control methods of heavy-haul trains.Firstly,the actual operation data of the HXD1 heavy-haul train on the Daqin line will be collected on site,Then the data is divided according to the running conditions of the train,which are divided into traction,electric brake and electro-air combined brake model.The recursive least squares method is used to identify each sub-model parameter and the rationality of the model is verified by data.Finally,the implicit generalized predictive controller is designed to track and control the target speed curve on the long steep grade.3.Taking the HXD1 heavy-haul train as the research object,this paper proposes the braking control strategy to generate the target speed curve and realizes the speed tracking control by using the established model and controller.The simulation results based on the actual line of Daqin line show that the control optimization method of this paper can realize the target speed tracking control of heavy-haul train on the long steep grade under the condition of line-limited speed.In order to ensure the safe operation of heavy-haul train on the long steep grade section,this paper develops a train braking control strategy based on multiple constraints and designs a multi-model train speed tracking controller.Through simulation experiments,the control proposed in this paper satisfies the operation requirements of heavy-haul train,which can provide a feasible theoretical guidance basis for driving training and lays a theoretical foundation for automatic driving of heavy-haul train in the future.