Operational Safety Evaluation Models And Approaches For Battery Electric Vehicle Based On Driving Trajectory

In recent years,new energy vehicles have developed rapidly in China,the battery electric vehicles have gradually become the main development direction of new energy vehicles based on the advantages of zero emission.However,the rapid growth of battery electric vehicles also makes urban road traffic resources increasingly tight,and their speed,acceleration and other related characteristics different from traditional fuel vehicles have also brought new challenges to their operational safety.In view of this,based on the GPS trajectory data of battery electric vehicles in Shenzhen,this paper analyzes the operating speed spatio-temporal characteristics of battery electric vehicles,and evaluates the operating safety of battery electric vehicles under multiple spatio-temporal scenarios,then comprehensively studies the driving state of battery electric vehicles based on the microtrips clustering results.The main research contents of this paper are as follows:(1)Based on the preprocessing of the trajectory data,the operating speed spatiotemporal characteristics of the battery electric vehicle are analyzed.This paper explores the spatio-temporal characteristics of the operating speed of battery electric vehicles from the characteristics of driving speed,over-speed ratio and amplitude,acceleration and deceleration frequency,and idle time ratio.The study found that the operating speed,over-speed and acceleration or deceleration status of battery electric vehicles are different under all road grades or time periods,and compared with conventional vehicles,battery electric vehicles have more higher speed,over-speed behaviors,and their accelerate and decelerate behaviors are more frequent,indicating that drivers were more likely to adopt aggressive driving behaviors when driving battery electric vehicles.(2)Speed parameters are used as indicators to evaluate the operational safety of battery electric vehicles under multi-temporal scenarios.Firstly,with starting performance,operating performance and braking performance as the first level indexes,an evaluation index system for the operation safety of battery electric vehicles based on speed parameters is constructed.Then,the CRITIC method and entropy method are combined to weight by game theory,and an improved combination weight-VIKOR evaluation method is proposed.Finally,battery electric vehicles in Shenzhen are selected for empirical analysis to evaluate the operational safety of battery electric vehicles under multi-temporal scenarios.The results show that the operation safety of battery electric vehicles is the worst during non-working hours and is generally lower than that of conventional vehicles,which verifies the reasonableness and effectiveness of the proposed evaluation method.The example verifies the rationality and effectiveness of the evaluation method.(3)Based on the microtrips,the driving status of battery electric vehicles is studied.Firstly,1757 micritrips of battery electric vehicles were extracted and 13 motion characteristic indexes were selected to build the microtrips database.Then,principal component analysis is performed on the motion characteristic indexes to obtain the final8 key indicators,which are used to describe the safety,efficiency and comfort of battery electric vehicles,and the K-means algorithm is used to cluster and analyze all for microtrips.Finally,combined with the clustering results,the driving state of battery electric vehicles is comprehensively evaluated,and a driving status characteristic pattern library containing 27 types of driving states of battery electric vehicles is generated.The research results can quickly judge the driving status of the battery electric vehicles according to the trajectory data of the monitored vehicle,and provide real-time driving suggestions for the driver based on the evaluation results,so as to achieve the purpose of optimizing the driving state.