摘要
According to the road adaptive requirements for the vehicle longitudinal safety assistant system an estimation method of the road longitudinal friction coefficient is proposed.The method can simultaneously be applied to both the high and the low slip ratio conditions. Based on the simplified magic formula tire model the road longitudinal friction coefficient is preliminarily estimated by the recursive least squares method.The estimated friction coefficient and the tires model parameters are considered as extended states. The extended Kalman filter algorithm is employed to filter out the noise and adaptively adjust the tire model parameters. Then the final road longitudinal friction coefficient is accurately and robustly estimated. The Carsim simulation results show that the proposed method is better than the conventional algorithm. The road longitudinal friction coefficient can be quickly and accurately estimated under both the high and the low slip ratio conditions.The error is less than 0.1 and the response time is less than 2 s which meets the requirements of the vehicle longitudinal safety assistant system.
针对汽车纵向安全辅助系统道路自适应的要求,提出了一种道路纵向附着系数估计方法.该方法能够同时适应高滑移率和低滑移率工况.首先基于简化魔术轮胎模型,利用递归最小二乘方法实时初步估计出纵向附着系数,然后将所估计出的附着系数与轮胎模型参数作为扩充状态,利用扩展卡尔曼滤波算法,滤除信号噪声,实现轮胎模型系数的自适应调整,最终实时获取准确的道路纵向附着系数估计,并通过车辆动力学软件Carsim仿真验证了算法的有效性和可行性.结果表明该算法优于传统算法,在高滑移率和低滑移率工况下都能够快速、准确地估计出道路附着系数,误差小于0.1,响应时间小于1 s,满足车辆纵向安全辅助系统的需要.
基金
The National Natural Science Foundation of China(No.61273236)
the Natural Science Foundation of Jiangsu Province(No.BK2010239)
the Ph.D. Programs Foundation of Ministry of Education of China(No.200802861061)
