面向全矢量线控车辆极限运动的分层式协同控制

Hierarchical Coordinated Control for Extreme Motion of Full-Vector Wire-Controlled Vehicles

装配四轮分布式驱动-转向(4WID-4WIS)底盘的全矢量线控车辆具备多可控自由度、高速稳定性强的特点,是极限工况稳定裕度和安全性较高的理想车型。为了解决全矢量线控车辆在极限工况下纵横向控制冲突危害行车安全的问题,提出一种基于模型预测控制(MPC)的分层式车辆纵向和横向运动协同控制方法。建立基于单轨模型的期望运动状态识别方法,设计模型预测控制器转换动力学目标,采用泰勒展开和前向欧拉方法对预测模型进行线性离散化处理;设计基于负荷率的轮胎力优化分配方法,利用反正切轮胎逆模型求解控制执行量。仿真结果表明,协同控制方法能显著提高车辆在不同路面下的极限运动稳定性,更精准地跟踪期望运动状态,扩大稳定裕度,保障行车安全。

The four-wheel independent drive-steering(4WID-4WIS)chassis architecture for full-vector wirecontrolled vehicles features multiple controllable degrees of freedom and superior stability at high speeds,which is an ideal solution to improve stability margin under extreme conditions and ensure driving safety.To address the issue of driving safety concerns arising from control conflicts under such conditions,a hierarchical coordinated control method for both longitudinal and lateral vehicle motions was proposed based on model predictive control(MPC).An expected motion state recognition method based on the single-track model was established,and the model prediction controller was designed to transform the dynamic target.The prediction model was linearized and discretized using Taylor expansion and the forward Euler method.Then the optimal tire force distribution method based on load rate was designed and the arctangent tire inverse model was used to solve the control execution values.The simulation results show that the proposed coordinated control method significantly improves the vehicle's extreme motion stability under different road conditions.It achieves more accurate tracking of the expected motion state,expands the stability margin,and ensures driving safety.