非匹配不确定性影响下的无人车路径跟踪控制

针对无人车在非匹配不确定性影响下的路径跟踪控制问题,设计一种基于线性矩阵不等式（LMI）的滑模控制器.首先,根据车辆运动学和动力学方程,同时考虑轮胎侧滑造成的不确定性、车辆侧偏约束以及随机干扰影响,建立车辆非线性不确定系统模型;然后,提出一种线性滑模路径跟踪控制方法,给出线性滑模面存在的充分条件,并推导出线性滑模面存在的显式公式,以保证约束于该滑模面的降阶等价系统的二次稳定性;最后,在SerretFrenet坐标系下验证车辆单、双移线运动时的路径跟踪控制效果.仿真结果表明,所设计的滑模控制器可以保证对参考路径的稳定跟踪,具有较强的鲁棒性.

Path following control for autonomous vehicles with mismatched uncertainties

In this paper, a sliding mode controller based on linear matrix inequality(LMI) is designed to solve the path tracking problem for autonomous vehicle systems with mismatched uncertainties. Firstly, the nonlinear uncertain system model is established based on the vehicle kinematics and dynamics equations, taking into account the uncertainties caused by tire sideslip and random interference etc. Then, a linear sliding mode path tracking control method is proposed for the linearized model. Sufficient conditions for the existence of a linear sliding surface are obtained by the aid of LMIs, and an explicit formula for the existence of a linear sliding surface is presented, which guarantees the quadratic stability of the reduced-order system. Finally, under the serret-Frenet coordinate system, the effectiveness of the proposed method is verified. Simulation results show that the desired path is tracked accurately and robustly with the designed controller.