水田植保机自主作业滑模抗干扰路径跟踪方法

Sliding Mode Anti-interference Path Tracking Method for Autonomous Operation of Paddy Field Plant Protection Machine

为解决无人化水田植保机在田间作业时上线速度慢、精度不高和抗干扰能力差的问题,提出了一种基于快速幂次趋近律和全局滑模控制的水田植保机路径跟踪控制方法。首先建立了含有滑移干扰项和航向角干扰项的水田植保机四轮异相位转向运动学模型,提出了一种基于全局滑模控制和快速幂次趋近律的直线作业跟踪转向控制算法,解决了滑模控制算法的抖振和趋近模态对干扰敏感的问题,使用Lyapunov判据检验了算法的收敛性。使用Matlab建立了仿真模型,对算法进行了仿真,相比基于指数趋近律和等速趋近律的滑模控制算法,本文算法的快速性更好。实际作业实验结果表明,该方法直线跟踪横向偏差绝对值最大为0.0778 m,能够有效提高自主导航控制系统的稳定性和快速性。

In order to solve the problems of slow on-line speed,low accuracy and poor anti-interference ability of unmanned paddy field plant protection machine in field operation,a kind of paddy field plant protection machine path tracking control based on fast power reaching law and global sliding mode control was proposed.Firstly,a kinematics model of four-wheel out-of-phase steering of a paddy field plant protection aircraft containing slip interference terms and heading angle interference terms was established,and the four-wheel out-of-phase steering model was simplified to a two-wheel out-of-phase steering model.A linear operation tracking steering control algorithm based on global sliding mode control and fast power approaching law was proposed,which solved the problem that the buffeting and approaching modes of sliding mode control algorithm were sensitive to interference.The Lyapunov criterion was used to test the convergence of the algorithm.A simulation model was established by using Matlab and the algorithm was simulated.Compared with the sliding mode control algorithm based on exponential reaching law and constant velocity reaching law,the speed of the algorithm was better.The actual operation experiment results showed that the maximum absolute value of the lateral deviation of the linear tracking of this method was 0.0778 m.Compared with the sliding mode control algorithm based on the constant velocity approaching law,the proposed method was effective in overcoming chattering and anti-interference,and can effectively improve the stability and speed of the autonomous navigation control system.