Research On The Stability Of Vehicle Driving On Highways Based On Virtual Prototyping

The development of automobile technology has led to a substantial increase in the actual driving speed of automobiles.The automotive industry is paying more and more attention to the safety and stability of automobiles.At the same time,the vigorous construction of highways has increased the proportion of road vehicles in transportation.As highways span vast areas,cars traveling on highways are often affected by pneumatic turbulence.For this reason,this thesis mainly carries on the relevant simulation research to the stability of the car traveling under high-speed road situation.This thesis first analyzed related theory of high-speed driving of the car,and mainly analyzed the actual side wind during high-speed driving of the car.In the natural wind part,the natural wind model of Wuhan was established according to the meteorological data,as well as side wind model of constant wind and gust.In the environmental wind part,for the case of cars crossing tunnels,the sine variation law was obtained from analyzing side wind speed data collected from road test.Secondly,based on the virtual prototype technology,a multi-degree-of-freedom vehicle model for simulation analysis was established in the application of ADAMS/Car.According to changing types of high-speed driving state of the vehicle,the stability of vehicle driving on highways was studied in two conditions.For the condition of rotation angle input of front wheel,the relevant test was selected for simulation with referring to controllability and stability test procedure for automobile,and the score of the evaluation indexes were calculated.For the condition of the input of side force,the side wind simulations under the corresponding side force were performed on the model.And the lateral displacement in 2th second was determined as the evaluation index of the side wind stability virtual test.The influence of side wind speed and driving speed on lateral displacement were also discussed.Combining the simulation results of two conditions,an evaluation method for evaluating the high road stability of vehicle model was proposed.Finally,in order to improve the performance of the vehicle model,the kinematics of the front suspension were optimized.Camber angle,toe angle,kingpin inclination angle,kingpin camber angle and wheel base were designated as optimization objectives.The joint optimization of response surface method and genetic algorithm were adopted.Comparing the simulation results before and after optimization of the model,it was found that the improvement of the kinematics of the front suspension can improve the highway stability of the model.However,in the event of strong side winds,higher driving speed will still produce greater lateral displacement.The safest approach is to consciously reduce vehicle speed and ensure driving stability.This thesis proposes the evaluation method for the highway stability of vehicle model,and the method for optimizing front suspension to improve model performance,and the suggestion for reducing speed to guarantee the stability under strong side winds.These provide a certain theoretical and practical reference value for the evaluation and improvement of model performance and safe driving.