基于趋近律滑模控制的智能车辆轨迹跟踪研究

Sliding Mode Control for Intelligent Vehicle Trajectory Tracking Based on Reaching Law

针对目前已有智能车辆轨迹跟踪控制存在跟踪精度低、鲁棒性弱等问题,结合滑模控制响应迅速、抗干扰能力强的优点,提出一种基于趋近律的滑模控制方法。提出的趋近律通过特殊幂次函数和反双曲正弦函数的组合,提高了系统状态的趋近速度并且平滑和限制了抖振现象,可实现控制车辆平顺快速跟踪参考轨迹。在Simulink软件上搭建了车辆运动学模型并进行轨迹跟踪仿真实验,通过与双幂次趋近律滑模控制进行对比验证了控制效果。仿真实验结果表明,相对于双幂次趋近律滑模控制,提出的趋近律滑模控制的车辆能更快地跟踪到参考轨迹,横向和纵向误差收敛速度明显增快,航向角抖振现象减弱,系统具有更快的趋近速度,并且抖振现象被削弱。

The existing intelligent vehicle trajectory tracking controller have the problems such as low tracking accuracy and weak robustness. In order to solve these problems and improve track tracking effect,a sliding mode control method based on a new reaching law was proposed because the sliding mode control had the advantages of quick response and strong anti-interference ability. The new reaching law was the combination of a special function and a inverse hyperbolic sine,which made sure that the system state can approach the sliding surface quickly whether it was near the sliding surface or not. The law really avoided the shortcoming of the traditional algorithms and improved the approaching speed of the controlled system and limited the vibration. The controller that used this method can control the vehicle to track the reference trajectory quickly. In order to prove the effectiveness of this method,a vehicle kinematics model was built and the trajectory simulation experiment was carried out in Simulink to compare the control effect of the new reaching law with the double power reaching law. The results of the simulation verified that the new reaching law had higher approaching speed and weaker vibration and it had better control effect. Controlled by the sliding mode control method based on the new reaching law,the convergence speed of horizontal and vertical errors of the vehicle kinematics model was significantly increased,the vibration of course angle error became weak,and the vehicle kinematics model can track the trajectory faster.