| With the improvement of road traffic safety requirements,AEB(Autonomous Emergency Break)system has been widely applied.For example,it is stipulated in China that commercial buses with more than 9m body produced after April 2019 must install AEB system conforming to national standards.However,typical European NCAP test conditions do not include extreme conditions,such as low friction coefficient and slope.The background of system adaptation demand of commercial buses is that there are many types of vehicles with different configurations and different service conditions.Therefore,the improvement of control algorithm and parameter optimization of AEB system have great practical application and engineering research value.In this paper,virtual test method is adopted to study the adaptive model of AEB system.In this way,the prototype development speed can be accelerated and the adaptation cost can be reduced.At the same time,the prototype of the controller was provided in the vehicle development process under the condition of low road adhesion.This study aims to improve the control strategy of AEB system under different pavement conditions through simulation calculation.The vehicle dynamics model and control algorithm model are established to simulate and verify the functions of the control module of the improved AEB system.The prototype controller is developed and the test experiment is conducted under actual vehicle conditions.Through modeling and simulation,the controller can output the optimal TTC(Time to Collision)threshold in real Time under different vehicle speed and road surface conditions.The calibration method and strategy selection method of control parameters under different road conditions are proposed.Through the simulation study of TTC safe distance model,the control method based on TTC value was explored and studied under different road adhesion conditions.The research gives the calibration method of the optimal TTC control algorithm parameters,as well as the selection scheme of first-level control strategy and second-level control strategy under different speed and adhesion conditions,so as to improve the success rate of TTC algorithm in avoiding collisions.The TTC control function related to vehicle speed and road friction coefficient is studied to achieve the goal of obtaining good collision avoidance effect under different vehicle speed and road conditions.Finally,by using ANN data processing and fitting the experimental data,a method of developing the controller prototype system is presented.This paper studies the AEB system based on a commercial bus test hardware,install the laser scanner and its processing information unit,the plant after connect car-mounted CAN test site and equipment to carry on the real vehicle experiment,experiment in this paper,we study the effectiveness of the control strategy and control function,for the development of the plant’s commercial buses AEB system provides technical test methods and development methods. |
