Analysis Of The Running Stability Of Center-axis Trains And Research On Anti-rollover

In today's logistics transportation industry,with the increase in freight volume and transportation mileage,traditional semi-trailer transportation can no longer meet the market demand.Compared with semi-trailer transportation,the central axle train adopts the combination of tractor and trailer,which can give full play to the advantages of large loading volume and high transportation efficiency.The coupling of the tractor and trailer using the coupling method reduces the turning radius of the train.While improving the steering flexibility of the vehicle.In July 2016,with the revision of GB1589-2016,the definition of center-axle trains was added,marking the market application of center-axle vehicles into a new stage.However,in the actual transportation process,there are still instability accidents such as folding,rollover,and tail flicking,especially rollover accidents have become the biggest threat to the safe driving of vehicles.Therefore,the driving stability of mid-axle trains was studied to establish The early warning algorithm model of the mid-axle trains and taking control measures to prevent the occurrence of rollover accidents are of great significance for improving the safe driving performance of the vehicle.In this paper,first of all,the center axis train is used as the research object,and the rollover mathematical model and tire model of the center axis tractor and trailer are established according to the principles of vehicle dynamics.The space state equation of the whole vehicle is obtained,and the whole vehicle model of Simulink simulation is built.Secondly,in the national standard test site,a steering stability test system was built,a road driving test was carried out under full-load conditions of the center-axle train,and a dynamic model of the center-axle vehicle was established in the truck dynamics simulation software Trucksim,and The same simulation parameters are set in the standard test site,and the correctness of the model is verified through road driving tests under typical working conditions.Then,in order to improve the safety of vehicles driving on the road,the lateral load transfer rate(LTR)of the central axle train is used as the evaluation index to establish the TTR rollover early warning algorithm,and the whole status LTR of the car is estimated based on the roll angle and roll angle speed of the tractor and trailer.Finally,the control strategy of the central axle train main torque is formulated,the method of unilateral braking is used to reduce the roll of the vehicle,and the Simulink and Trucksim joint simulation model is built.The linear quadratic controller is used to solve the two typical models.The optimal torque applied under working conditions.The research results show that the joint simulation model can pre-warn the dangerous conditions of the vehicle in advance,and can trigger single-side braking,reduce the towing of the tractor and the yaw of the trailer,and improve the safety and stability of the vehicle.