Research On AEB Control Strategy Considering Comfort

AEB(Autonomous Emergency Braking)technology,as an important content in the field of intelligent driving,has always been an important technical means to reduce the incidence of traffic accidents,and is also an inevitable trend in the development of the automobile industry.In order to ensure that AEB technology can play a full role in the real driving environment and effectively reduce the accident rate,it is necessary to ensure the equipment rate and utilization rate of on-board AEB system.However,the assembly rate of AEB technology is directly affected by the intuitive experience of drivers and passengers on the AEB system.Therefore,it is necessary to study AEB control strategies based on the considerations of comfort to improve user experience.To this end,this paper takes AEB control strategy as the research object,establishes a new braking safety distance model considering comfort and designs a hierarchical controller to achieve corresponding braking control.The specific work content is as follows:1.A simplified model of the vehicle longitudinal dynamics system is establish and the accuracy of it is verified through the simulation.Combined with the longitudinal dynamics of the whole vehicle and the power and speed transmission of the engine and transmission train in the actual driving,the longitudinal motion control model of the vehicle is built.The errors of vehicle acceleration and velocity based on simulation control are within 0.2m/s~2 and 0.5km/h respectively,which proves the accuracy of the model.2.A new braking safety distance model is proposed to optimize the comfort of the braking control process and target.The braking deceleration change buffer and a maximum braking deceleration are set to reduce driving discomfort caused by the intervention of AEB system.Based on the specific analysis of typical AEB test scenarios,the AEB decision objective is further optimized to improve the AEB system performance in terms of comfort.On this basis,combined with the relative kinematics analysis of the two vehicles,a unified safety distance model is established.3.The corresponding AEB system controller is designed to realize the control of deceleration.The upper controller uses the model predictive control to constrain the braking deceleration and the jerk,realizing the planning of the desired braking deceleration in accordance with the design requirements.The lower controller adopts PID control to correct the actual deceleration of vehicle,to ensure that the actual deceleration of the vehicle follows the expected deceleration.4.The simulation tests and the perception experiment are carried out.Matlab/Simulink and Car Sim co-simulation platform is built at first.Then,based on typical working conditions such as CCRs,CCRm,and CCRb,tests are made to analyze the effectiveness of the AEB control strategy designed in this paper.Besides,the perception experiment is carried out using the BAIC smart vehicle experimental platform to verify the feasibility of the AEB control strategy in this paper.The simulation tests are carried out using the designed AEB control strategy.The test results show that the ego-vehicle basically can achieve deceleration and collision avoidance in accordance with the designed deceleration and jerk,and the final motion state is consistent with the preceding vehicle,under different test conditions.The final relative distances between the two vehicles are between 3.6m and 4.1m,distributing relatively concentrated.It can also prove the effectiveness of the AEB control strategy proposed in this paper,which can successfully achieve collision avoidance and driving comfort under different working conditions.In addition,the relative distance error of the two vehicles obtained through the perception experiment is less than 1m,and the speed error is less than 1km/h.This means that the perceptual information it provides for the decision and deceleration control of AEB system is comparatively accurate,which further proves that the AEB control strategy proposed in this paper is realistic and feasible.