Research And Implementation Of Test Drive Performance Evaluation System For Second-hand Cars

As the auto industry continues to grow and people’s economic standards improve,car ownership continues to grow,leading to the expansion of the used car industry.At present,online used car platforms are gradually taking shape,but they cannot guarantee that people can safely,reliably and economically buy the right car.The car information provided by used car e-commerce platforms for users is relatively basic and does not include the actual driving performance descriptions of the cars,and users need to feel the actual performance of the cars through field test drives,and there is no set of common methods to realize the evaluation and comparison of car performance.In response to the above problems,this paper designs a test-drive performance evaluation system based on used cars,which remotely realizes the evaluation of car performance based on driving data,synthesizes the results into a comparable evaluation report,and realizes the evaluation interface and dynamic performance display interface through software.This paper mainly carried out the following research work:(1)The car OBD system,on-board video acquisition system and car fuel consumption calculation method are studied,the terminal collection of data and cloud processing are realized,and the performance base parameters of car dynamics and fuel economy are calculated based on the OBD data.(2)The method of driving scenarios is proposed,and the pre-processed car data is subdivided into different categories of driving scenarios according to the different characteristics of driving status and driving gears,which effectively weakens the influence of factors such as driving behavior and environment,and provides a basis for the analysis of car performance.(3)The evaluation methods of vehicle fuel economy and dynamics were studied,and accurate performance evaluation was realized by using k-means++ clustering,kernel density estimation,Bayesian fitting and other algorithms respectively according to the characteristics of different kinds of driving scenarios,and the comparison standards of evaluation results were unified.(4)A performance scoring system was designed,real-world tests were conducted and the accuracy of the scoring results was analyzed.The fuel economy evaluation method was verified to be accurate and stable by comparing the driving conditions and highway fuel consumption test method.(5)Test drive performance evaluation software was implemented to provide a car performance evaluation report based on the evaluation results,which can compare the actual performance of different models from various aspects,and a dynamic performance display interface was designed from driving videos and synchronized car mechanical data to provide dynamic information of real-time test drives.The study shows that the used car test drive performance evaluation system is not affected by driving environment or driving behavior,and can provide reliable performance evaluation of the vehicle after the prescribed driving time and road testing.This system can provide car buyers with more accurate model performance evaluation remotely,avoid the inconvenience of field test drives,effectively increase the purchase rate of desirable vehicles,and can promote the emerging online used car market.