Simulation Research On Running Stability And Ride Comfort Of Four-group Virtual Train

Virtual rail train is a new type of rail vehicle developed to relieve urban traffic pressure and improve transportation efficiency.It is generally designed as a 3 to 5 section marshalling,and its structure is similar to articulated passenger cars and automobile trains.The four-module virtual track train has a maximum design speed of 80km/h,and consists of two tractors and two trailers.The length of the vehicle is about 35 m.There are many degrees of freedom.There may be tail-flicking,rolling,and folding during driving.Other instability phenomena affect the stability and smoothness of the vehicle.Therefore,studying the running stability and smoothness of the four-module virtual track train is of great significance for ensuring the safe operation of the train and subsequent optimization design work.Based on the UM dynamics software,this paper establishes the suspension,steering,body,articulated disc and other subsystem models of the four-module virtual rail train,and then builds the vehicle dynamics model.Establish a kinematics-based multi-axis steering control strategy,and control the virtual rail train to perform all-wheel steering through co-simulation with the UM dynamic model.In order to verify the effectiveness of the steering strategy,a circular curve tracking simulation was performed.The results show that the multi-axle steering strategy can effectively improve the steering performance of the vehicle.This paper draws on the test standards of automobiles,articulated passenger cars,and automobile trains,and conducts a simulation analysis of the running stability and comfort of the four-module virtual rail train.The driving stability analysis mainly includes the simulation analysis of straight-line driving,single lane change and angle step input test.According to the straight-line driving simulation,the damping of the hinged disc at each speed is matched and optimized to improve the straight-line driving stability of the train.Because the train is undergoing a steering test at a higher speed,the vehicle is seriously instability,so this time only analyzes the single-lane change and angle step input test for the vehicles below the medium(40km/h)and low(20km/h)speeds.Driving stability.From the simulation results,it can be seen that at low speeds,the train has good obstacle avoidance and steering stability;at medium speeds,after the train completes the steering test,the train cannot quickly return to the stable driving state in a short time,and the driving stability needs to be further improved.Based on the existing conditions,a ride comfort road test was carried out on the train under no-load and low-speed conditions,and the accuracy of the dynamics model was verified by comparing the test and simulation results.The simulation analysis of the ride comfort of random road input and pulsed road input at different speeds is carried out using the dynamic model.According to the simulation results of the train ride comfort at each speed,it can be seen that the train ride comfort is good.