Design Of Vehicle Drivability Evaluation System Based On LabVIEW

Driveability evaluation is the driver’s intuitive expression of the driver’s performance of the vehicle engine and its power transmission system,including various factors and overall performance presented by the vehicle.The driver’s subjective feelings under the dynamics of the vehicle reflect the transient quality of the vehicle and the entire vehicle during driving.At present,China’s related technical research in this field is still in its infancy.There is a lack of unified methods and objective standards in the evaluation of vehicle driveability,and the degree of confidentiality of foreign driveability related technologies is too high.,There are very few related public drivability evaluation documents and data;therefore,this article has designed a relatively complete drivability evaluation scoring system through vehicle tests,related tests and related calculations under different test conditions.The main research contents of this paper are as follows:First,develop a subjective evaluation test plan.The characteristic index data is output by three experienced drivers with subjective evaluation according to the test specifications.The vehicle status under different working conditions is defined as: starting,accelerating,constant speed,decelerating,shifting,Tip in(suddenl y stepping on the accelerator)and Tip out(emergency release throttle),through the evaluation status of the corresponding sub-evaluation items for enumeration analysis,the establishment of characteristic index calculation and weight analysis related models and subjective evaluation scoring mechanism.Secondly,the fuzzy analytic hierarchy process was used to establish a subjective evaluation index system.Three pilot drivers made subjective evaluation scores for the evaluation elements of the index layer,and the subjective scores were calculated by the weight coefficients of the characteristic indicators and evaluation elements and the driver’s subjective evaluation scores,and fuzzy comprehensive scoring,to establish a sexual mapping relationship between the subjective and subjective evaluation score s between the characteristic indicators and the subjective evaluation scores.On the basis of the subjective evaluation test plan,the data acquisition system and function module definition are designed through LabVIEW virtual instrument programming software,the collected characteristic indexes are calculated and analyzed by sample mean,coefficient of variation and correlation analysis method,and the correlation between characteristic indexes and evaluation elements is established.Recognition of the vehicle state using the naive Bayes classification algorithm.The vehicle state recognition system is built by the Mathscript function module of LabVIEW software.The underflow problem of the naive Bayes classification algorithm is optimized.The test results prove the superiority of the optimized naive Bayes classification algorithm.Finally,the SVM algorithm is used to evaluate the driving performance of the vehicle.According to the test results,the algorithm has errors in the evaluation and scoring of the starting state,deceleration state,and shifting state.Through the establishment of an index layer improvement plan,the model parameters are optimized by particle swarms.And after processing the corresponding characteristic indicators,the deceleration state recognition effect is improved,and the results are consistent with the real score.Only the starting state and the shifting state have small errors,indicating that the comprehensive effect of the characteristic index data preprocessing and model optimization vehicle state recognition has been improved,the experiment proves the simple application of the model in engineering,and the result of the experiment is displayed through the LabVIEW custom interface.