Research On Modeling And Control Strategy Of Autonomous Emergency Braking System

In view of the current problems including increased car ownership,increased traffic congestion,and frequent rear-end collision accidents which results in more and more loss of life and property,Autonomous Emergency Braking(AEB)which can avoid or mitigate collision by active braking has become a hot research topic in the field of automobile active safety technology.This paper summarizes the research progress of AEB technology from its working principle,development path,application status and regulation.The key technologies related to the comprehensive performance of AEB system have been summarized including collision avoidance strategy,braking execution technology and front-end perception technology.Through AMESim and Carsim software,the vehicle dynamics model and the brake actuator model in the simulation model of the AEB system are established respectively.The subsystems of the vehicle model in the Carsim software are configured in detail based on vehicle dynamics modeling,and the hydraulic components of the brake actuator in the AMESim software are configured in detail based on the brake actuator modeling which can provide a model basis for the subsequent co-simulation environment establishment.Based on the analysis of existing road adhesion coefficient identification methods,this paper proposes a road adhesion coefficient identification algorithm based on peak adhesion coefficient surface which considering the difference of optimal slip ratio and peak adhesion coefficient between different roads.Simulink/Carsim co-simulation is used to verify the correctness and effectiveness of identification algorithm proposed in this paper based on high adhesion coefficient road,low adhesion coefficient road and docking road which can provide theoretical support for the design of the subsequent AEB collision avoidance strategy.Based on the safety performance of active braking system,road identification conditions and front vehicle motion status,this paper compares and analyses the current AEB collision avoidance strategies,and establishes AEB collision avoidance strategies that can meet the comprehensive performance requirements of AEB system under different vehicle speeds and different road conditions.Based on the working principle of the brake actuator of AEB system,this paper establishes t he control model of the bottom solenoid valve and motor,the wheel cylinder pressure control model based on the threshold control method,the expected braking deceleration control model based on the vehicle inverse longitudinal dynamic model and brake anti-lock control model based on the double logic threshold method of wheel angle acceleration and slip rate.Based on Simulink,Carsim and AMESim software,this paper configures the environment interface of the co-simulation software environment and builds a complete AEB co-simulation software environment.The hardware-in-the-loop test environment of AEB is built based on the AEB electronic control unit and hardware-in-the-loop test bench.In the high adhesion coefficient road test conditions and low adhesion coefficient road test conditions,the accuracy of the brake actuator control strategy in the co-simulation software environment is verified based on the AEB hardware-in-the-loop test environment.Finally,the accuracy of the established AEB collision avoidance strategy is verified in the co-simulation software environment based on the C-NCAP test scenario and the HIL test results.