Research On The Handling Stability Performance Robustness Design And Implementation Of A SUV Vehicle

With the continuous expansion of the domestic automobile market,the market share of self-owned brand cars has gradually increased under the initiative of the national government.However,many self-owned brands use reverse development as the main development method.While ensuring product quality,they also shorten the time to market and reduce development costs and risks.The development of vehicle chassis as the core technology of automobile production and manufacturing,especially the impact of chassis tuning technology on product quality in the development process,has been the focus of research by major companies.This article combines the vehicle chassis development project of an auto company.Point to problem that a certain SUV sample car in the chassis tuning stage,as long as the hard point is not changed as much as possible,repeated modification of the suspension parameters has a long tuning cycle,and the stability performance improvement is not obvious.Using the co-simulation method of Isight,Carsim and matlab based on the Isight platform to optimize the whole vehicle handling stability and shorten the period of tune-up.(1)The prototype front and rear suspension model is built in Adams software.Verify the accuracy of the model through K&C test,and analyze the K&C characteristics of the front and rear suspension.(2)Build a complete vehicle model in Carsim software based on the characteristic parameters of each system.Measured the characteristic parameters such as vehicle inertia moment parameters,suspension system,steering system,engine performance characteristics,transmission system,braking system,and tire system through various system tests were input into Carsim for modeling and simulation.The accuracy of the vehicle model is verified by comparing the vehicle handling stability test report(such as steady-state rotation condition,frequency sweep,linear acceleration braking condition,etc.)with the simulation results.(3)Study robust design theory and methods,and propose a robust optimization design method suitable for the characteristics of the problem.(4)Using the co-simulation method of Isight,Carsim and matlab based on the Isight platform to optimize the whole vehicle handling stability.Firstly,the front and rear suspension characteristics,spring stiffness,absorber damping,and stiffness of the stabilizer bar are used as design variables,and load and center-of-mass height are used as noise to analyze handling and stability of the whole vehicle under the steady-state cornering and the fish hook test conditions.The comprehensive evaluation score of the steady-state cornering test N_w and the comprehensive evaluation score of the fish hook simulation test Ns are objective responses.Then analyzing sensitivity to eliminate insensitivity factors.Utilized RSM to fitting the objective functions,and the second order response surface approximation model obtained by regression analysis indicates the relationship between the suspension system variable and the objective response.Adopted the NSGA-Ⅱalgorithm to optimize the multi-objective robustness of vehicle handling stability.The optimal solution set of the design variables is obtained.Finally,Monte Carlo is used to verify the robustness of the vehicle stability performance.(5)The optimized suspension characteristic parameters are used as performance indicators to optimize the robustness of front and rear suspension systems.Analyzing the influence of bushing stiffness on C characteristic parameters of suspension.Utilized the Taguchi method to robust design optimization.The optimal solution of the bushing stiffness is obtained,and the Monte Carlo is also used to verify the robustness of the suspension system.(6)Finally,the optimized scheme is used as a reference for chassis tuning,so as to reduce the range of variables that need to be modified.The results prove that the consistency of the subjective and objective evaluation of the vehicle handling stability performance is achieved.On the basis of not affecting the comfort,the curve driving performance is improved to 7.5 scores from the previous 6.5 scores.the tuning period,at the same time,is shortened to 2 days from the previous 7 days.