The Quantification Of Subjective Evaluation In The Development Of Chassis Handling And Stability

In recent years,the growth rate of China's auto industry has gradually slowed down.Take 2019 as an example: the production and sales of automobiles have decreased by 7.5% and 8.2% year-on-year respectively,and the low growth rate of the industry will be normal in the future.The cold winter of the auto industry indicates that the fierce competition in the auto industry will be different in the future.At the same time,the prices of joint venture car companies continued to drop,and new models equipped with new technologies and platforms were continuously put into the Chinese market.Therefore,how to create high-productivity automotive products in this environment is a topic facing every autonomous automobile company.Vehicle driving dynamics performance is the key to vehicle dynamic characteristics and an important dimension of products competitiveness,which directly determines the subjective experience of drivers and passengers during vehicle driving.The handling and stability of the chassis is an important part of vehicle driving dynamics.Good handling stability can bring a pleasant driving experience and a sense of safety to the driver.During the development of vehicle chassis handling and stability,the evaluation of the development status of handling and stability is the key to forming a closed-loop development.There are two evaluation methods: objective test methods using test equipment and subjective evaluation methods using the subjective feelings of professional evaluators as a reference.Chapters 2 and 3 of this paper systematically analyze the specific content,methods,and standards of these two methods in the development of handling and stability.However,the two evaluation methods have their own advantages and disadvantages.Although the domestic OEMs have carried out these two evaluation methods at the same time,they have not organically combined these two evaluation methods.Since subjective and objective evaluations are generally carried out after the production of trial-produced vehicles,which is delayed behind the guidance of early design and development.At present,the value of domestic subjective and objective evaluation activities is mainly reflected in the accumulation of objective data to provide guidance for the development of next-generation models,guide the later chassis tuning through subjective evaluation.This paper aims to explore the quantitative relationship between objective testing and subjective evaluation based on the development of chassis handling and stability.The second chapter discusses common objective test methods and key performance indicators of chassis handling stability based on domestic and foreign standards and a company's enterprise standards,and makes a preliminary pre-screening of each objective test indicator based on theoretical knowledge.The third chapter introduces the common subjective evaluation methods and indicators based on the subjective evaluation system of Ford R202 and the actual subjective evaluation system of some company,and introduces the ten-point subjective evaluation scoring mechanism.In chapter 4,based on actual data,taking handling as an example,the method for extracting quantitative relationships between subjective and objective evaluation of chassis handling and stability is introduced in detail,and the analysis and interpretation are given based on the results.This method is suitable for any performance index that has both subjective and objective evaluation methods in the vehicle development process,such as: ride comfort,power performance,etc.The fifth chapter summarizes the full text,and points out the guiding significance of the research results in this paper for the development of chassis handling and stability,points out the work directions in the future.The paper introduces the development of subjective and objective evaluation methods in detail,and establishes a general method for extracting quantitative relationships between subjective and objective evaluation indicators.This method is of great significance for the target decomposition in the initial stage of vehicle development.The results will play an important role in the independent development capability of the chassis stability development of Chinese automobile enterprises.