基于滑模控制算法的自适应跟车巡航研究

Research on Adaptive Cruise Based on Sliding Mode Control Algorithm

自适应巡航控制(ACC)为汽车驾驶提供了便捷性,通过对跟车控制上层控制算法以及下层执行策略进行设计,加强巡航控制功能的跟随性、安全性和舒适性。设计了考虑制动安全距离和舒适加速度的变时距跟车策略,基于滑模变结构控制算法实现跟车功能,建立包含速度偏差与距离偏差的滑模控制面,并改进趋近率缓解系统抖振。基于Carsim动力学仿真软件搭建ACC自适应巡航仿真车辆与交通环境,通过节气门开度、制动主缸压力作为Carsim的输入信号实现对车辆的闭环控制,与MATLAB/Simulink实现联合仿真。将使用传统PID算法跟车策略的实车实验与改进后的仿真跟车算法对比,结果验证了发动机逆模型和制动器逆模型的合理性,同时,车辆控制的精确性和舒适性都显著提升,跟车距离更具安全性。

The Adaptive Cruise Control(ACC)brings convenience to driving a car.By designing the upper-level control algorithm as well as the lower-level execution strategy for following control,the following,safety and comfort of the cruise control function are enhanced.A variable time distance following strategy considering braking safety distance and comfortable acceleration is designed,the following function based on sliding mode variable structure control algorithm is realized,a sliding mode control surface including speed deviation and distance deviation is established,and the approach rate mitigation system is improved.The ACC adaptive cruise simulation vehicle and traffic environment are built based on the Carsim dynamics simulation software.The closed-loop control of the vehicle is realized by using the throttle opening and brake master cylinder pressure as the input signals of Carsim,and the joint simulation is realized with Matlab/Simulink.Comparing the real vehicle experiment using the traditional PID algorithm following strategy with the improved simulation following algorithm,the results verify the rationality of the engine inverse model and the brake inverse model.At the same time,the accuracy and comfort of vehicle control are significantly improved,and the following distance is safer.