Research On Train Driving Strategy Of Heavy Haul Moving Block System

As China's “transportation power” strategy puts forward the requirements of speeding up the improvement of railway freight capacity and the transfer of bulk cargo transportation to railway and water transportation,it has become an urgent need to improve the transportation capacity of heavy haul railway.At present,fixed block mode is widely used in heavy haul lines in China,and moving block technology which can shorten the interval between trains and improve the transportation capacity of line has been extensively used in urban rail transit.However,due to the great differences in the line characteristics of heavy haul railway and urban rail transit,as well as the differences in weight,braking method and braking implementation processes of heavy haul train and urban rail transit train,the existing traction and braking driving strategies used in the moving block system of urban rail transit can not be directly applied to heavy haul trains.Therefore,it is of great significance to study the train driving strategy of heavy haul moving block system.Combined with the characteristics of heavy haul lines and trains in China,this paper studies the train driving strategy of heavy haul moving block system from the generation of target speed curve and the design of speed control method.The main works of this paper are as follows:(1)The dynamic model of heavy haul train is established.The hysteresis characteristics of traction and braking system of heavy haul train are analyzed,and the hysteresis models of traction & electric braking system and air braking system are established based on the experimental data.Then,the operation process of the train is calculated.(2)Method of generating target speed curve for heavy haul train under the moving block system is designed.For gentle slope operation scenario,considering the limitation of locomotive traction and the deceleration ramps,acceleration ramps and neutral sections existing in the actual line,the target speed curve is generated based on the adaptive step size and time equivalent algorithm.For continuous long and steep downgrade operation scenario,a method of generating target speed curve and operating condition sequence based on improved particle swarm optimization algorithm is proposed,and according to the safe and stable operation rules of heavy haul train,the constraint models of cyclic braking and passing over of neutral section are established.(3)A speed control method for heavy haul train based on fuzzy predictive control is proposed.Aiming at the problems of nonlinear,large lag and external disturbance in the operation of heavy haul train,a speed controller is designed in combination with fuzzy control and predictive control.The controller adjusts the traction force and electric braking force with reference to the target speed curve,and applies air brake timely according to the input operating condition sequence in the continuous long and steep downgrade and braking stop stages to realize the automatic control of heavy haul train.(4)A model for verifying the driving strategy of heavy haul train under the moving block system is built,and then combined with the actual line data of the Shuohuang Railway,the operation of train in gentle slope and continuous long and steep downgrade scenarios is simulated.The output of the model is analyzed and compared with the actual driving curve.The results show that the target speed curve generated by the driving strategy in this paper meets the actual driving needs in terms of safety and punctuality,and the generated operating condition sequence is close to the actual operating condition output by the driver.At the same time,the maximum tracking error of the fuzzy predictive controller is ±0.9km/h,and the controller shows good control effect in tracking accuracy and change rate of train acceleration.52 pictures,14 tables,76 references.