Adhesion Control Of Heavy-haul Train Based On Optimal Creep Speed

With the country’s attention to the transportation industry,heavy-haul train is becoming more and more important in railway freight,and the operation safety of heavy haul train has gradually been concerned.The traction system and adhesion control system are the key links of train safe operation.Improving the adhesion utilization rate of wheel-rail is the main way to improve the traction performance of train,so the research on adhesion control of train has great engineering significance.In this paper,the adhesion mechanism of heavy train in traction condition is analyzed.In order to improve the traction performance of heavy train and ensure the safe and stable operation of the train,anti-skid adhesion control and optimal adhesion control of heavy train are studied respectively.The specific research process is as follows:1.Firstly,on the basis of reviewing a large number of literature,the present situation of adhesive control at home and abroad is introduced and analyzed,mainly from two parts:readhesive control and optimal adhesive control.Secondly,the sticking principle of the heavy train is explained,and a simplified train dynamics model is established based on the analysis of the traction system,running process and sticking mechanism of the heavy train.2.Aiming at the problem that heavy duty trains are prone to skid under bad track surface conditions,an adhesion control strategy based on anti-skid constraint is proposed.The anti-skid problem is considered as the problem that the creep speed is always in the adhesion zone.Based on the established train dynamics model,a full-dimensional state observer was designed to estimate the adhesive force which could not be measured in real time.Secondly,the barrier Lyapunov function was introduced to constrain the creep speed,and the expected creep speed was tracked and controlled by backstepping control method.The simulation results show that the anti-slip control algorithm can realize the constraint of creep speed and accurate tracking of expected value,and solve the phenomenon of skidding during the operation of heavy duty train.3.In order to solve the problem that the traction force of heavy train can not play effectively under bad weather or track surface conditions,an optimal adhesion control strategy of heavy train considering system uncertainty is proposed to ensure the train is in the best traction performance.First series sliding mode observer based on adhesion coefficient,followed by using the least square method with forgetting factor and set the optimal creep velocity gradient descent method,the final step delay estimation method is used to estimate the uncertainty of the system,design of discrete integral sliding mode controller to control the motor torque to creep speed stability at best creep speed all the time,The simulation results show that the optimal adhesion control system can realize the high-precision tracking control of the target value.In order to improve the traction performance of heavy duty train,this paper studies the anti-skid binding adhesion control and optimal adhesion control,and verifies the effectiveness and feasibility of the two control methods by Matlab/Simulink simulation,and achieves the desired controller design objectives.It provides a theoretical basis and technical support for the adhesion control of heavy duty train in the future.