双电机履带式水稻收获机底盘自动导航系统设计与试验

Design and experiment of automatic navigation system for rice harvester with dual-motor crawler chassis

针对人工操作履带式收获机进行再生稻头季收获碾压率高、对行稳定性差,以及现有电动履带式机械大田作业精度低等问题,设计一套双电机履带式底盘自动导航系统并进行了试验验证。以自主设计的用于水稻收获的双电机履带式底盘为基础,基于田间滑移模型推导了底盘转向半径与两侧驱动电机转速关系,并设计了自动导航模糊控制器。采用双天线RTK-GNSS获取双电机履带式底盘的实时位置和航向角信息,由自动导航系统的横向模糊纠偏控制器和两侧电机转速PID控制器实时控制两侧电机转速,实现作业路径自动跟踪。路面试验结果显示:双电机履带式底盘水稻收获机行驶速度为0.6、1.0 m/s时,自动导航系统的平均横向偏差分别为0.015、0.021 m。田间试验显示:双电机履带式底盘水稻收获机行驶速度为0.6 m/s时,自动导航系统的平均横向偏差为0.050 m。研究结果表明,相较于使用电控液压转向改装的导航系统,本导航系统控制量精准、响应速度快,跟踪误差小,可用于再生稻头季机收对行作业以降低碾压率。

A set of automatic navigation system for rice harvester with dual-motor crawler chassis was designed and tested to solve problems of high rolling rate,poor alignment stability of manual-operated crawler harvester and low field operation accuracy of existing electric crawler machinery for ratoon rice harvesting in the first season.Based on the dual-motor crawler chassis self-designed for the rice harvesting,the relationship between the steering radius of the chassis and the speed of the driving motors on both sides was derived on the basis of the field slip model.An automatic navigation fuzzy controller was designed.The dual-antenna RTK-GNSS is used to obtain the real-time position and heading angle information of the dualmotor crawler chassis.The lateral fuzzy correction controller of the automatic navigation system and the PID controller of the motor speed on both sides control the motor speed in real time to realize the automatic tracking of the working path.The results of road test showed that the average lateral deviation of the automatic navigation system was 0.015 m and 0.021 m when the dual-motor crawler chassis was driven at 0.6m/s and 1.0 m/s.When the driving speed was 0.6 m/s,the average lateral deviation of the automatic navigation system was 0.050 m.Compared with the navigation system modified with electronically controlled hydraulic steering,this navigation system has precise control volume,fast response speed and small tracking error.It can be used in the row-to-row operation of ratoon rice in the first season to reduce the rolling rate.