基于运动特性的农机导航控制方法  

Control Method for Navigation Based on Kinetic Characteristic of Agricultural Machinery

作　　者：白晓平[1,2] 孟鹏 王卓 时佳[1,2] BAI Xiaoping;MENG Peng;WANG Zhuo;SHI Jia(Shenyang Institute of Automation,Chinese Academy of Sciences,Shenyang 110016,China;Liaoning Provincial Key Laboratory of Agricultural Equipment Intelligent Technology,Shenyang 110016,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院沈阳自动化研究所,沈阳110016 [2]辽宁省农业装备智能化技术重点实验室,沈阳110016 [3]中国科学院大学,北京100049

出　　处：《农业机械学报》2021年第11期21-27,共7页Transactions of the Chinese Society for Agricultural Machinery

基　　金：广西创新驱动发展专项资金项目(AA17202013)。

摘　　要：农业机械(农机)运动学模型的精度影响导航控制精度和稳定性,为提高农机路径跟踪控制器精度,提出了一种基于运动特性的农机导航控制器设计方法。该方法主要是对传统二轮车运动学模型建模方法进行改进,针对传统二轮车模型小角度近似替代(方向角等于横摆角)的缺点,采用加入侧偏角的方法优化农机运动学建模过程。采用相同的控制方法(状态反馈控制)和不同的运动学模型设计控制器进行对照实验。直线路径跟踪时,侧偏角对模型精度影响较小,引入侧偏角可以在一定程度上影响农机的跟踪精度;曲线路径跟踪时,侧偏角对方向角的变化影响较大,可以大幅影响路径跟踪精度。以安装有自动导航设备的拖拉机为实验平台进行实地实验,结果表明:直线行驶的最大横向误差平均值为0.0454 m,绝对平均误差平均值为0.0149 m,标准差平均值为0.0119 m;曲线行驶的最大横向误差平均值为0.1613 m,绝对平均误差平均值为0.0688 m,标准差平均值为0.0434 m;基于本文提出的优化模型设计的路径跟踪控制器对直线路径跟踪有一定提升,对曲线跟踪精度有大幅提升。The accuracy of the kinematics model of agricultural machinery affects the accuracy and stability of navigation control.In order to improve the accuracy of the path tracking controller of agricultural machinery,a design method of navigation controller based on the motion characteristics of agricultural machinery was proposed.The method was mainly an improvement of the traditional two-wheeled vehicle kinematics modeling method.Aiming at the shortcomings of the small-angle approximation replacement(the direction angle was equal to yaw angle)of the traditional two-wheeled vehicle model,the method of adding the slip angle was used to optimize the kinematics modeling process of agricultural machinery.The same control method(state feedback control)and different kinematics models were used to design controllers for control experiments.When tracking a straight path,the slip angle had little effect on the model accuracy,and the introduction of slip angle can affect the tracking accuracy of agricultural machinery to a certain extent.When tracking a curved path,the slip angle had a great impact on the change of the direction angle,which can greatly affect the path tracking accuracy.Using a tractor equipped with automatic navigation equipment as an experimental platform for field experiments.The experimental results showed that the maximum lateral error of straight driving was 0.0454 m,the absolute average error was 0.0149 m and the standard deviation was 0.0119 m.The maximum lateral error of curve driving was 0.1613 m,the absolute average error was 0.0688 m and the standard deviation was 0.0434 m.The data showed that the path tracking controller designed based on the proposed kinematics model optimization method can improve the linear path tracking to a certain extent,and can greatly improve the curve tracking accuracy.

关 键 词：农业机械 控制器 运动学模型 导航 侧偏角 路径跟踪 

分 类 号：TP24[自动化与计算机技术—检测技术与自动化装置]