Dynamics Modeling,analysis And Measurement Of Medium-speed Maglev Trains With Mid-mounted Linear Motor

During the thriving development of the high-speed and low-speed maglev train,in National University of Defense Technology,people have designed a medium-speed maglev trains with mid-mounted linear motor,which is mainly composed of bogie,secondary-system and body.In order to study the dynamic performance of the maglev train.,we have established the dynamics modeling of the whole vehicle,which contains 6 degrees of freedom involving forward,lateral,floating and sinking,rolling,pitching and yaw.And we have built the virtual prototype model of the train based on the LMS Virtual.Lab Motion,a multi-body dynamics simulation software.Besides,we have designed the pose measurement experiments to verify the accuracy of the dynamics modeling by comparing the position and orientation relationship of bogies between experimental measurements and the results of modeling simulated.The main contents of this paper are given below:1.Based on the structure analysis of the medium-speed maglev trains with midmounted linear motor,we have done the acceleration analysis of the rigid body,established the dynamic equations of moving rigid bodies and solved the expressions of binding force.Firstly,we have derived the acceleration and angular acceleration of the rigid body of the maglev vehicle,and we analyzed the force relationship between structures and established the dynamic equations of the car body,the left and right levitation modules and the middle linear motor by Newton-Euler equations.And then,regarding the air spring,all the rods and bushes as the spring damping system,we have deduced the expressions of electromagnetic force,air spring and sliding table force,guiding mechanism force,rod transmission force and beam force according to the vehicle running posture.Finally,the vehicle dynamics mathematical model is established based on Simulink.2.Applying the LMS Virtual.lab Motion multi-body dynamics simulation software,according to the motion relationship of the structures of the maglev,we have established the relationship between the traction mechanism,anti-roll decoupling mechanism,air spring,guiding mechanism and the restraint and force of car body.The magnetic track relationship between the electromagnet and the track is established by using the virtual track.Finally,the virtual prototype simulation model of vehicle is established based on the 204 m line of National University of Defense Technology.3.We have come up with a method to determine the position and attitude of the levitation module through a laser displacement sensor.The sensor is mounted on an electromagnet to illuminate the track to get the position and attitude of the levitation module.The position of the middle position motor is determined through the measurement of the position relationship between the middle motor and the levitation module by the measuring arm.Finally,the position and posture of the bogie are obtained.4.Under the working conditions of straight track and circular track,comparing the simulation results of the mathematical model and the virtual prototype model,the results of the simulation of the two models are consistent.Under the operating condition of the 204 m test line of National University of Defense Technology,the simulation results of Motion virtual prototype model are compared with the actual measurement of posture and posture,and the results are consistent with each other.Finally,it verifies the accuracy of the mathematical model of maglev vehicle dynamics.The dynamic modeling and virtual prototype model of the motor-driven vehicle built in this paper have been established and verified by the actual measurement results.The model is worthwhile to be used as a reference for the dynamic performance and structural optimization of the track irregularity of Maglev vehicles.