Research On The Protection Effect Of Automatic Emergency Braking System For Riders Based On Typical Scenario

With the increase of the number of two-wheeled vehicles(TWs:Motorized and non motorized two-wheeled vehicles),the number of TW traffic accidents have increased significantly.The collision form and accident severity of car-to-TW are more complex than that of pedestrian.The Autonomous Emergency Braking System(AEB)can effectively reduce the severity of injury to TW riders.The protection effect of AEB system on vulnerable road users in the actual road traffic environment has become the focus of attention from all walks of life.Research on National Automobile Accident In-Depth Investigation System(NAIS)database data and road traffic accident scene classification provides data support for the effectiveness test of AEB system.Based on the real road traffic accident data,this paper studies the characteristics of car-to-TW accidents and the risk model of TW riders'serious injury(AIS3+)and death,and predicts the protection effect of AEB system on TW riders.The research results will provide the reference for designing AEB system that is more in line with the characteristic of road traffic accidents in China,so as to better improve the safety design of vehicles and the driving safety of TW riders.The main contents of this paper are as follows:(1)Select 353 cases car-to-TW accidents from the NAIS database.The parameters influencing the results of car-to-TW accidents were analyzed and the clustering parameters were determined.Combined with the hierarchical clustering analysis,chi square test and the severity of TW riders'injury,the typical features of each type of scenario are extracted.Finally,five kinds of car-to-TW test scenarios that meet the characteristics of China's road traffic are obtained.(2)Taking the second type of typical scenario as an example,each parameter is concreted and an accident test scenario is built in PreScan software.In Simulink,the longitudinal collision avoidance strategy of AEB based on TTC algorithm is built,and the joint simulation model of PreScan-MATLAB/Simulink is established.(3)By using logistic regression analysis of serious injury and death accidents of TW,it is found that the risk of serious injury and death of TW riders is not related to the vehicle's type,the TW's type and the TW's speed,but significantly related to the vehicle's speed.To determine the degree of reducing the risk of serious injury and death of TW riders by AEB system as the effectiveness evaluation index of AEB system.(4)From the second kind of scene,40 typical cases are selected as the cases to be evaluated.The influence of sensor field of view,detection range,braking advance time,braking deceleration and triggering width on the protection effect of TW riders is studied by using the control variable method.Through the design of orthogonal test and simulation analysis,it is found that the key parameters affecting the effectiveness of AEB system are trigger width,followed by braking advance time and braking deceleration.The simulation analysis of 40 accident cases to be evaluated shows that when the field of view is 100°,the braking advance time is 1s,the braking deceleration is 7m/s~2,the detection distance is 25m,and the trigger width is 8.75m,the protection efficiency of AEB system for AIS3+accidents and fatal accidents of TW riders is 67.5%and 76.7%,respectively.