基于自适应快速终端滑模的车轮滑移率跟踪控制

针对汽车对连续、快速和稳定的车轮滑移率跟踪控制的需求，提出基于自适应快速终端滑模的车轮滑移率跟踪控制策略. 基于Burckhardt轮胎模型建立车轮滑移率跟踪控制模型，将模型简化过程中的不确定性考虑成复合干扰项，将轮胎侧向力对纵向力的影响考虑成未知参数. 利用双曲正切函数和终端吸引因子设计改进的跟踪微分器，平滑车轮滑移率跟踪误差和估计车轮滑移率跟踪误差的一阶导数. 以车轮滑移率跟踪控制模型和改进的跟踪微分器输出为基础，基于自适应快速终端滑模控制理论，设计对复合干扰项具有强鲁棒性的车轮滑移率跟踪控制律；基于投影算子理论设计自适应律来实时补偿未知参数，利用LaSalle不变性原理证明了闭环系统的渐近稳定性. 利用车辆动力学软件仿真验证提出的控制律的可行性和有效性. 结果表明，提出的车轮滑移率跟踪控制策略具有精度高和鲁棒性强的优点.

Wheel slip tracking control of vehicle based on adaptive fast terminal sliding mode control method

A novel wheel slip tracking control strategy was proposed based on adaptive fast terminal sliding model control method aiming at the requirement of the vehicle for the continuous, fast and stable wheel slip tracking control. The wheel slip tracking control model was established based on Burckhardt tire model. The uncertainty during the process of model simplification and the influence of the tire lateral force on the tire longitudinal force in the wheel slip tracking control model were considered as the lumped uncertainty and the unknown parameter, respectively. The modified tracking differentiator was deduced based on hyperbolic tangent function and terminal attraction factor in order to smooth the wheel slip tracking error and estimate the derivative of the wheel slip tracking error. The wheel slip rate tracking control law with strong robustness for the system uncertainty was proposed based on the adaptive fast terminal sliding mode control theory according to the wheel slip tracking control model and the outputs of the modified tracking differentiator. The adaptive law was proposed based on projection operator theory to compensate the unknown parameter. The asymptotic stability of the closed-loop system was proved using the LaSalle invariance principle. The feasibility and effectiveness of the proposed wheel slip tracking control strategy was verified based on vehicle dynamics simulation software. Results show that the proposed wheel slip tracking control strategy has high accuracy and strong robustness.