基于激光雷达的果园行间车辆自动导航控制  

Design of Intra-row Automatic Navigation Control System of Orchard Vehicles Based on LiDAR

作　　者：邓贤 李秋洁[1] 高程前 刘旭 袁鹏成 周宏平[1] Deng Xian;Li Qiujie;Gao Chengqian;Liu Xu;Yuan Pengcheng;Zhou Hongping(College of Mechanical and Electrical Engineering,Nanjing Forestry University,Nanjing 210037,China)

机构地区：[1]南京林业大学机械电子工程学院,南京210037

出　　处：《农机化研究》2023年第2期29-35,共7页Journal of Agricultural Mechanization Research

基　　金：国家自然科学基金项目(31901239);江苏省基础研究计划青年基金项目(BK20170930)。

摘　　要：针对果园自主导航过程中车辆偏航、植株缺失等问题,设计了一款基于激光雷达的果园行间履带式车辆自动导航控制系统,并模拟标准化果园环境进行试验以验证系统性能。首先,采用二维激光雷达(Light Detection and Ranging,LiDAR)获取树干点云数据,对点云数据进行坐标变换;其次,通过识别树干边界起始点进行树干定位;再次,提出两步树行分割法将树行分割为左右两行,利用最小二乘法分别对两侧定位点进行直线拟合,将树行中心线作为导航路径;最后,将电机期望转速作为比例微分(Proportion Differentiation,PD)控制器的输入,使车辆沿树行中心线自动行驶。树行分割试验表明:当感兴趣区域内植株无缺失、单株缺失、双株缺失且无航向偏差、无横向偏移时,树行分割正确率均为100%;双株缺失存在横向偏差和航向偏差、三株缺失不存在横向偏差和航向偏差时,树行分割准确率为96.4%;三株缺失存在横向偏差或航向偏差时,树行分割准确率92.9%。电机控制试验表明:电机调速系统具有快速响应的优点,且稳定性良好。导航控制试验表明:当车辆以0.8m/s速度行驶且存在0.5m的初始横向偏移时,系统能够在2m内将横向偏差抑制在0.05m以内,最大横向偏差为0.03m,均方根误差为1.91cm。In order to solve the problems of vehicle yaw,plant loss and disturbance of adjacent trees during orchard autonomous navigation,an automatic navigation control system of tracked vehicle based on Light Detection and Ranging(LiDAR)was designed,and the orchard environment was simulated to test the system performance.Firstly,the 2D LiDAR was used to obtain the cloud data of tree trunk point,and perform coordinate transformation,normalization and other preprocessing on the point cloud data,and the first-order lag filtering algorithm and window method are used to remove point cloud data anomalies.point;Secondly,the coordinates of trunk center were calculated by identifying the starting point of trunk boundary.Then,a two-step tree row division method was proposed to divide the tree row into two left and right rows,and the least square method was used to conduct linear fitting on the two sides of the anchor points respectively,and the center line of the tree line was taken as the navigation path.Finally,the motor differential speed was used as the input of the Proportion Differentiation(PD)controller to make the vehicle drive automatically along the center line of the tree.The tree row segmentation test showed that the correct rate of tree row segmentation is 100%when there is no missing plant,single plant missing,double plant missing,no yaw angle,and no lateral offset in the area of interest,the tree line segmentation accuracy was 96.4%in the case of double plant deletion,and 92.9%in the case of three plant deletion without transverse deviation or yaw.The motor speed control experiment showed that the motor speed control system has the advantage of rapid response and good stability;The navigation control test showed that when the vehicle is traveling at 0.4 m/s and there is an initial lateral deviation of 0.5 m,the system can restrain the lateral deviation within 2 m to 0.05 m,the maximum lateral deviation is 0.03 m,and the root mean square error is 1.91 cm.

关 键 词：果园车辆 自动导航 激光雷达 树行分割 PD控制 

分 类 号：TP242[自动化与计算机技术—检测技术与自动化装置]