Research On Speed-Governing System Of Rail Vehicle Collision Based On Linear Induction Motor

With the gradual improvement of the rail vehicle network and the continuous improvement of the speed of the rail vehicles,the importance of the safety of the rail vehicles is becoming more and more prominent.In order to improve the passive safety of the rail car,accurate and effective collision test is essential in the design process of the rail car.In the traditional rail vehicle collision test,the vehicle hits the wall after obtaining the initial speed and after a period of inertia movement.The scheme is difficult to control the collision speed accurately,and it needs a lot of experience to accumulate,which makes the whole experiment not accurate and efficient.In order to solve the above problems,this paper focuses on the research of a high efficiency and high precision speed regulating system for rail vehicle collision test.In view of the shortcomings of traditional collision test-bed,this paper proposes a high precision track vehicle speed regulation scheme based on linear induction motor.The scheme is based on the traditional track vehicle test line,and the linear induction motor is used to improve the system,which is a new collision test platform.First,the driving vehicle is used to accelerate the test vehicle to the target speed and then decouple,and then the motor is used to control the speed of the test vehicle accurately so that it can finally impact the force measuring wall at the specified speed.In addition,the hardware part of the system is designed and built from the aspects of security and practical requirements.Every real vehicle test needs a lot of preparation and high cost.So the motor should be fully simulated before the real vehicle test.Therefore,the model of linear induction motor considering the end effect is established and the corresponding vector controller is designed.Finally,the effect of the controller is verified by simulation.Because the main purpose of this system is to speed control,it is very important to get accurate speed signal.Considering the low sampling frequency of the sensors used in practice and the loss of speed signals through wireless transmission,a speed observer based on the high-order sliding and expanding state observer is designed,The high precision and high sampling frequency signals are obtained by the fusion of observation speed and sensor acquisition speed.In the design of speed observer,the flux of motor is estimated based on the super spiral second order sliding mode algorithm and the extended state observer algorithm;Then,the relationship equation between motor speed and flux is obtained by Lyapunov method;Then,the two speed signals are fused by Kalman filter;Finally,the performance of the methods is compared and verified by simulation.Through the design of the whole system scheme and the above theory,the high precision track car speed regulating platform based on linear induction motor is finally built.The design,selection,installation and debugging of the electrical and control part are included.At the same time,the control program and the display interface of the upper computer based on PLC are designed.The speed observer algorithm is realized in the controller by collecting the current and voltage data of the motor by Hall sensor.The control effect of the system is verified by the platform.The final experimental results meet the precision demand of the control speed.