基于轮胎力动态估计与主动转向的新型ESP系统

车辆电子稳定系统能有效提高车辆在极限工况下的方向稳定性.针对传统直接横摆力矩控制(DYC)没有考虑轮胎附着力极限的局限,提出一种基于轮胎动力动态估计(TDE)算法的新型车辆电子稳定控制系统(ESP),在此基础上,通过主动前轮转向(AFS)协同控制,最大化利用车轮附着力.采用多元回归统计算法设计TDE控制器,采用基于统计数据的多项式拟合获得车轮附着力边界极限和最优动态滑移率上限值;采用模糊逻辑算法设计AFS控制器,补偿因附着力达到极限引起的横摆力矩不足.仿真结果表明,通过与AFS的协同控制,新型ESP能够在改善车辆的方向稳定性的同时,大幅降低车轮制动控制力,减少对车辆纵向速度的影响.

A Novel Electronic Stability Program Based on Tire Dynamic Force Estimation and Active Steering Technology

The vehicle Electronic Stability Program (ESP) can effectively improve the vehicle stability under extreme driving condition. However, traditional Direct Yaw Control (DYC) does not consider the adhesive limitation of tire forces. In order to overcome this shortage, a novel ESP algorithm was proposed based on Tire Dynamic Force Estimation (TDE) in this paper. Combined with Active Front Steering (AFS), this algorithm can make the maximum use of available tire forces. Based on multiple variables regression algorithm and polynomial fitting, a TDE controller was designed to obtain the tire adhesive boundary and the upper limit of optimal dynamic slip ratio. Based on fuzzy logic algorithm, an AFS controller was designed to compensate the insufficient yaw moment caused by adhesive forces limitation. This developed algorithm was verified through simulations, and the results show that the proposed novel ESP can significantly enhance the cornering stability by collaborative control with the AFS. Meanwhile, the proposed algorithm can significantly reduce active braking force of the wheels and alleviate undesired impact on the vehicle longitudinal speed.