Simulation And Optimization Of Vehicle Minimum Time Handing And Stability Based On ADAMS

The development of automobile industry occupies an important position in the whole manufacturing field.With the development of society and the progress of science and technology,people's requirement for technical level is getting higher and higher.With the improvement of highway traffic network,more and more automobiles are running at high speed.With the increase of vehicle speed,the handling stability of automobiles is obviously weakened.Most traffic accidents are due to lateral imbalance caused by steering during high speed driving.With the development of vehicle research technology,the performance of the minimum time handling and stability has been widely concerned.In the aspect of performance research of high-speed overtaking,the performance of the minimum time handling and stability can well reflect the performance of vehicle handling and stability in the process of high-speed driving.In this paper,combined with the evaluation index system of the minimum time handling and stability,the Mitsubishi Lancer model is analyzed by experiment and the minimum time handling and stability is finally optimized and improved.This paper starts from the following research.(1)Using ADAMS to analyze the correlation of Mitsubishi Lancer model,simplify the whole vehicle system reasonably,divide the whole vehicle model into seven subsystems,such as front and rear suspension system,and then model each subsystem separately.On the basis of the existing indexes for evaluating driver's busy,rollover risk and side slip risk,and considering the vehicle's driving and adhesion performance comprehensively,the indexes for evaluating the minimum time handling and stability,such as the performance of dynamic index,the ability of the tire's grasping index and the performance of response index,are added,and the evaluation index for the minimum time handling and stability are also included.(2)The simulation curve and minimum time handling and stability performance are analyzed by the double-lane-shifting experiment.The simulation curve shows that the steering wheel angle response has obvious deviation from the target value and the steering wheel sensitivity is low.It provides a certain idea for the optimization analysis of the minimum time handling and stability.Through the simulation curve of the minimum time handling and stability performance,the changes of driver burden evaluation index,roll hazard index,side slip hazard index,dynamic evaluation index,tire grip evaluation index,response evaluation index and comprehensive evaluation index in the double-lane-shifting test can be obtained.Through the analysis,the change trend of each index value in the course of driving is obtained,and then the change of the minimum time handling and stability performance in the course of driving is obtained according to the change of the index value.(3)With the refining of the influence factors of understeering characteristic,the effects of front and rear suspension roll stiffness,static design parameters SDF and the suspension equivalent lateral stiffness on understeering of automobiles are analyzed.The simulation results show that the suspension roll center position is too high,and the suspension equivalent lateral stiffness is too large.In order to further improve the understeering characteristic of automobiles,the analysis started with the geometric design of suspension and the improvement of bushing stiffness.Through sensitivity analysis,the geometric design hard point parameters and the bushing corresponding parameters of the suspension with high effect of lateral stiffness and roll center are obtained.By optimization,the roll center decreased from the original 96.75 mm to 86.65 mm,the suspension equivalent lateral stiffness has changed from 82.69% to 75.63%,falling to a reasonable limit.The understeering characteristic of vehicle has been further improved.By comparing the various evaluation indicators and comprehensive evaluation indicators of minimum time handling and stability,the understeering characteristic is improved,and the minimum time handling and the stability performance is further improved.(4)The influence of vehicle structural parameters such as center of mass height,center of mass position,front and rear suspension stiffness on minimum time handling and stability is studied.Through the double-lane-shifting experiment of the whole vehicle,the changes of the comprehensive evaluation indexes of vehicle lateral acceleration,roll angle,yaw rate and minimum time handling and stability are compared with the simulation curves to study the changes of minimum time handling and stability The results show that moving forward the center of mass,reducing the height of center of mass and increasing the roll stiffness of front suspension are helpful to improve the performance of the minimum time handling and stability.