基于T-S MPC的车辆自适应巡航控制策略研究

Research on vehicle adaptive cruise control strategy based on T-S MPC

针对于汽车自适应巡航系统面对复杂工况时自适应性不强的问题,提出了一种基于T-S模糊变权重模型预测控制(Takagi-Sugeno fuzzy model predictive control,T-S MPC)的自适应巡航分层控制策略。首先上层控制器基于安全距离模型将自适应巡航系统划分为定速巡航模式、多目标优化控制的跟随模式和紧急制动模式;下层控制器基于车辆逆动力学模型,将上层控制器输出的期望加速度转变为节气门开度或制动压力;其次考虑到权重系数对控制精度的影响,建立基于T-S模糊控制的变权重模型预测控制器;最后搭建Carsim Simulink联合仿真平台,验证控制策略的准确性、适应性和跟踪响应速度。结果表明,在定速巡航工况时,T-S MPC控制方法跟踪响应时间为1.54 s,较PID和传统MPC控制跟踪响应快;在跟随和混合工况时,T-S MPC控制方法均方根误差为分别为0.3073、2.775,均低于PID、PID+LQR和传统MPC控制的均方根误差、并且自适应性好,有效提高了跟车性能与安全性。

Aiming at the problem that the adaptive cruise system of automobile is not adaptive when facing complex working conditions,an adaptive cruise hierarchical control strategy based on Takagi-Sugeno fuzzy model predictive control(T-S MPC)is proposed.Firstly,the upper controller divides the adaptive cruise system into fixed-speed cruise mode,following mode with multi-objective optimal control and emergency braking mode based on the safety distance model.The lower controller transforms the desired acceleration output from the upper controller into throttle opening or braking pressure based on the inverse vehicle dynamics model.Secondly,considering the influence of the weighting coefficients on the control accuracy,the control strategy is established based on the T-S fuzzy control based variable weight model predictive controller.Finally,Carsim Simulink joint simulation platform is built to verify the accuracy,adaptability and tracking response speed of the control strategy.The results show that the tracking response time of the T-S MPC control method is 1.54 s,which is faster than the tracking response of PID and traditional MPC control in the cruising condition.In the following and mixing conditions,the root mean square error of the T-S MPC control method is 0.3073 and 2.775,which is lower than that of the PID,PID+LQR,and traditional MPC control,and it has good adaptability,which effectively improves the following performance and safety.This effectively improves the following performance and safety.