Research On Evaluation Indexes System And Evaluation Model For Secondary Task Driving

Traffic accident has become a significant social and economic problem. According tostatistics,25%~50%of the total traffic accidents were caused by driver distraction, andsecondary task driving is the primary cause leading to driver distraction. Generally, driversactively involved in distracting activities and accounts for as high as36.4%of crashes.However, owing to the lack of driving behavior analysis technology and theoretical tools,researches on secondary task driving safety are immature and the research achievements arerelatively scattered. Therefore, in this study, taking secondary task driving safety as researchobject, fusing the information of driver visual behavior and vehicle running status, targetingat accurately evaluating the safety of secondary task driving, finding the deviationcharacteristic of various parameters under different driving conditions as the main line, thesecondary task driving safety evaluation index system and evaluation model are deeplystudied. The results can provide theoretical and technical support for driving safety research,and have important theoretical significance and practical application value. The specificresearch contents are as follows:1. Review of existing research results. The dissertation proposes a research frame aboutsecondary task driving research, and includes4categories: secondary task type, effects ofsecondary task driving on different parameters, secondary task driving evaluation model, andsecondary task driving behavior. Based on the analysis of current situation, problemsexisting in these researches are founded. At last, considering the existent problems ofevaluation indexes lacking systematicness, poor visual behavior research, and lackingsecondary task driving safety evaluation model, further studies will be carried out in thisstudy.2. Design and implementation of information acquisition system for secondary taskdriving safety analysis. For accurate analyses the safety of secondary task driving, thesecondary task driving safety evaluation index system combining measures of driver visualbehavior and vehicle running status is proposed. In addition, experiment project is designed,including installing the collecting devices, developing the traffic scenes, standardizing theexperiment process, selecting the measures, selecting secondary task types, etc. Based on theequipments of Smarteye eye tracking system and driving simulator, information acquisitionsystem for secondary task driving safety analysis is developed. Subsequently, the technology of multi-threads synchronization is used to integrate multi-source information to achievetime synchronization. Finally, methods of data extract, removing abnormal data and dataanalysis are developed, which could provide data support for following research.3. Analysis of drivers visual behavior under different driving conditions. First, theforms of visual behavior are systematically analyzed and the distinguish criteria betweenfixation and saccade is designed. Second, after a thorough comparative analysis of methodfor driver gaze areas dividing, a new method based on driver character to divide gaze areas isdeveloped. Using analysis of variance, deviation characteristics of driver visual behaviorincluding fixation, saccade and blink are studied deeply. Parameters significantly affected bysecondary task are extracted and evaluation indexes for secondary task driving safetyevaluation are determined.4. Analysis of vehicle running status under different driving conditions. Analysis ofvehicle running status is conducted from two aspects, lateral and longitudinal running status.Parameters of average speed, standard deviation of speed, standard deviation of acceleration,steering wheel angle, and steering entropy are analyzed deeply. Based on essential featuresof the vehicle running status analysis, method of analysis of variance (ANOVA) is used toquantify the effects of secondary task on driving performance measures. At last, the indexsystem for evaluating vehicle running status is constructed.5. Method research for building secondary task driving model. On the basis of analysisof the objective for secondary task driving safety evaluation, evaluation objects, andrelationships between objects, an approach to construct secondary task driving safetyevaluation model is developed, that is Fuzzy Analytic Network Process (F-ANP).Subsequently, the theory and method of the F-ANP, evaluation index system constructing,and weight array of indexes obtaining are studied.6. Building secondary task driving safety model by using F-ANP. Based on the analysismethod of correlation coefficient, we analyze the indexes relationships between driver visualbehavior and vehicle running status, and construct the secondary task driving safetyevaluation index system. Furthermore, this study introduces a method that the evaluationindexs are selected and filtered, and establishes the driving safety remark set and constructsthe single factor assessment matrix for each driver. In addition, the global weight of eachindex is calculated and the driving safety levels are determined. Finally, due to the maximummembership grade principle, the driving safety level is determined and the secondary taskdriving safety evaluation model is completed.7. Study on the applicability of secondary task driving safety evaluation model. Data obtained from secondary task driving experiment are processed and analyzed by using thesecondary task driving safety evaluation model built in this study. Based on the evaluationresults, we classify and analyze driving safety according to driving condition, drivingexperience and the type of secondary tasks.