基于非线性观测器的路面附着系数估计方法

Estimation Approach of Road Friction Coefficient Based on Nonlinear Observer

提出了一种基于非线性观测器的路面附着系数估计方法。针对转向工况下路面附着系数的实时估计问题,建立了车辆的非线性动力学模型,构造了全维观测器,以估算轮胎回正力矩。根据车辆的侧向动力学特性,将车载传感器测量值与车辆模型输出值之间的偏差作为非线性观测器的Luenberger类型反馈项,实现了对车载传感器的充分利用。通过李雅普诺夫(Lyapunov)稳定性分析,确定了非线性观测器反馈环节的增益,并在Matlab/Simulink仿真环境下对该方法进行了验证。仿真结果表明,该估计方法在不同路况下具有较高的准确性。

In this paper, an algorithm for estimating road friction coefficient based on nonlinear observer is proposed. To solve the problem of the real-time estimation of road friction coefficient while steering, a nonlinear vehicle model is established, and a full-order observer is developed to estimate front tire aligning moment. According to the vehicle lateral dynamic characteristics, and the error between the measure- ments of vehicle sensors and the outputs of vehicle model as observer＇s Luenberger-type feedback terms, the vehicle sensors are fully used. By means of Lyapunov stability theory, the observer gain is confirmed, and the estimated algorithm is verified under Maflab/Simulink environment. The simulation results show that the estimated algorithm has a good performance under different road conditions.