摘要
我国商用车AEB性能要求和试验方法标准的发布,推动了AEB在商用车领域的发展与应用。本文针对半挂汽车列车制动距离长、质心高等特点,结合驾驶员紧急制动的经验,提出了一种基于BP神经网络预测碰撞时间TTC的AEB控制策略。首先,设计了上层控制器,基于不同驾驶员在不同紧急制动场景下碰撞时间的数据,利用BP神经网络算法得到预测模型,从而计算出触发AEB系统的预警时间阈值和紧急制动时间阈值;再以前车与本车的相对距离、相对速度和前车的减速度为输入,通过模糊控制规则得到本车期望的减速度;接着,设计了下层控制器,采用期望减速度前馈控制和减速度偏差PID反馈控制相结合的方式,得到各车轮所需的轮缸制动压力;并基于滑移率滑模控制防止车轮抱死,提高紧急制动时的安全性、舒适性和横摆稳定性。最后,在TruckSim中建立CCRb、CCRm、CCRs 3种测试场景,对控制策略进行了验证。结果表明,本文所提出的控制策略能有效避免碰撞的发生,为半挂汽车列车AEB系统的设计和研究提供了理论依据。
The promulgation of the standard on the performance requirements and test method of autonomous emergency baking(AEB)for commercial vehicles in China promotes the development and application of AEB in the field of commercial vehicles.In view of the long braking distance and high mass center height of tractor-semitrailer combination,an AEB control strategy based on time to collision(TTC)predicted by BP neural network is proposed in this paper,drawing on the driver’s experience of emergency braking.First of all,the upper controller is designed.Based on the data of TTC in different emergency braking scenes with different drivers and by using BP neural network algorithm,the prediction model is obtained to calculate the time thresholds of early warning and emergency braking,and with the relative distance and relative speed between front vehicle and ego vehicle and the deceleration of front vehicle as inputs,the desired deceleration of ego vehicle is obtained by fuzzy control rule.Then,the lower controller is designed.By combining the forward control of desired deceleration and the PID backward control of deceleration deviation,the braking pressure in wheel cylinder needed for each wheel is obtained,the wheel lock is prevented by sliding mode control,and the safety,comfort and yaw stability in emergency braking are enhanced.Finally,CCRb,CCRm and CCRs three test scenes are set up in TruckSim to verify the control strategy.The results show that the control strategy proposed can effectively avoid the occurrence of crash and this study provides a theoretical basis for the design and research of the AEB system in tractor-semitrailer combination.
作者
郭祥靖
孙攀
邓杰
刘勇
刘壮
刘双平
Guo Xiangjing;Sun Pan;Deng Jie;Liu Yong;Liu Zhuang;Liu Shuangping(Dongfeng Commercial Vehicle Technology Center,Wuhan 430056)
出处
《汽车工程》
EI
CSCD
北大核心
2021年第9期1350-1359,1366,共11页
Automotive Engineering
关键词
半挂汽车列车
自动紧急制动控制系统
BP神经网络算法
模糊控制
PID控制
滑模控制
tractor-semitrailer combination
autonomous emergency braking control system
BP neural network algorithm
fuzzy control
PID control
sliding mode control