Research On AEB Control Strategy Considering ESC Response Characteristics

AEB is an important part of active safety technology that meets people’s needs for safety in car driving and meets regulatory requirements.Electronic Stability Control(ESC),as the braking actuation structure for AEB systems,meets the needs of the AEB system for actuators,and both have been the subject of considerable research at home and abroad.However,the design of AEB control strategies rarely takes into account the response characteristics of the ESC system.Therefore,the study of AEB control strategies based on the response characteristics of ESC systems is important for the integration of the two.This paper starts from the composition of AEB system,in order to have good response characteristics of the actuator,choose ESC hydraulic system as the actuator of the AEB system designed in this paper.At the same time,because the braking system is in active braking state during AEB operation,the wheel cylinder pressure control strategy of active braking is designed for the actuator.The reason of ESC response delay caused by signal propagation between AEB system and ESC hydraulic system is analyzed.The control strategy of AEB system is integrated with deceleration control module.Firstly,the composition of electronic hydraulic braking system is studied,and the working state of ESC hydraulic actuator is analyzed in the process of active braking.Then the composition of the hydraulic control unit HCU and the working principle of the key parts of the ESC system are analyzed,and the important parameters are set.And establish the physical model of ESC hydraulic system.Based on the above work,the pressure estimation algorithm of brake wheel cylinder based on table lookup method and the pressure control algorithm of brake wheel cylinder based on neural network are designed.At the same time,experiments are designed to obtain the pressure following effect under the pressure control strategy and the response characteristics of ESC system.Secondly,the control strategy of AEB system is designed,which mainly consists of collision avoidance strategy and deceleration control strategy.The collision avoidance strategy of TTC model and safety distance model is proposed,in which the safety braking distance threshold is calculated in proportion to the relative distance.At the same time,considering the response of the ESC system,the deceleration control strategy is designed using the cascade control frame,with the outer ring as the deceleration ring and the inner ring as the pressure ring.The outer loop controller is composed of feedforward and feedback control.The feedforward control is designed based on longitudinal dynamics model,and the feedback control is designed based on PID control.According to the test standard of AEB system,the corresponding experiment is designed to obtain the control effect of the designed AEB control strategy.Finally,in order to verify the effect of the integration of ESC system and AEB system,hardware-in-the-loop experiments were conducted to verify that under various operating conditions,the vehicle can be effectively controlled to brake in time and effectively avoid the occurrence of collisions,and to compare the effect of the integration of the two with the control effect of the AEB control strategy without the integrated deceleration control module.