Research On Parameter Optimization And Control Of Centre Axle Trailer Train Based On Lateral Stability

With the release and implementation of GB 1589—2016(Limits of dimensions,axle load and masses for motor vehicles,trailers and combination vehicles),centre axle trailer train,one new type conveyance,has been playing important role.Centre axle trailer train has the characteristics of flexibility and high transport efficiency and can reduce the transportation cost effectively through the operation of swapping trailers and bodys.However,centre axle trailer train is the combination of multi-body and there are more coupling of degree of freedom(DOF),longer longitudinal dimension,and these also make traffic accident easily happened when the speed is high.So the study on lateral stability of centre axle trailer train is extraordinary significative for improving its safety performance.According to the theory of rigid body dynamics,simplified model of centre axle trailer train was proposed and the differential equation of motion was built.The theory analysis model and multi-DOF nonlinear simulation model were established in Simulink and TruckSim respectively.Lateral stability testing system was built based on VBOX,RT gyroscop,etc equipments.Single lane change test of prototype centre axle trailer train and its simulation were carried out respectively.Through the data processing and analysis,it is found that the related index of lateral stability of centre axle trailer train in test have good agreements with those in simulation,verifying the correctness of theoretical model the reliability of the simulation model.Lateral stability of centre axle trailer was enhanced from the view of improving structure parameters.Comprehensive evaluation score model of lateral stability,the optimization target,was built by taking some index such as the rearward amplification(RA)for yaw rate into consideration,and the standards,Criterion thresholds and evaluation of controllability and stability for automobiles,was also referenced.There are six important parameters such as the location of traction pin(traction ring)and the center of mass were selected as the optimization variables in this paper.The constraint condition in optimization process are the limits of dimensions for centre axle trailer train in GB 1589-2016.Uniform experiment and multiple linear regression theory were utilized to optimize the parameters.After the optimization of structure parameters,direct yaw moment control(DYC)strategy was also designed in this paper.The fuzzy controller,its inputs are vehicle speed and road coefficient and angle rate of tire,was built to control the DYC intervention time dynamically according to different driving condition.In order to follow the steady-state yaw rate and articulated rate,PID controller and brake force distribution plan were designed to adjust brake force dynamically.DYC control strategy was verified through the TruckSim-Simulink co-simulation platform.The results show that the RA for yaw rate and RA for lateral acceleration,lateral LTR,articulated rate of centre axle trailer train coud be reduced effectively on the condition of single lane change in high speed by parameter optimization and applying DYC,and the lateral stability was improved significantly.