摘要
针对车辆果园行间自主导航出现的车辆偏航、非相邻树行干扰、植株缺失、树行弯曲等问题,提出一种基于激光雷达的行间路径提取方法,构建多样化虚拟果园环境仿真行间路径导航过程,评估路径提取算法性能。行间路径提取时,采用二维激光雷达(Light detection and ranging,LiDAR)获取果园树干测量数据,通过中值滤波削弱测量噪声,设计椭圆感兴趣区域(Region of interest,ROI)提取相邻树行,提出两步树行分割法获取相邻树行数据,通过最小二乘法拟合树行直线,将树行中心线作为导航路径。行间导航仿真时,建立虚拟果园环境和LiDAR测量模型,基于仿真测量数据生成导航路径,经过一阶数字低通滤波后实时控制车辆运动。仿真实验中,设置果树种植偏差为±20 cm,树干直径偏差为±3 cm,LiDAR测量误差为±3 cm。实验结果表明,本文方法在车辆偏航、缺树、曲线树行等情况下均能准确提取导航路径,在偏航角不大于15°、横向偏差不大于1 m、缺树率不大于25%时均能将车辆轨迹与道路中心线的横向偏差控制在±14 cm内。
Aiming at the problem of autonomous intra-row navigation of orchard vehicles,an intra-row path extraction method based on light detection and ranging(LiDAR)was proposed,and a diversified virtual orchard environment to simulate the intra-row path navigation process and evaluate the performance of path extraction algorithm was constructed.A 2D LiDAR was used to measure orchard trunks during the extraction of intra-row path and median filter was used to weaken the measurement noise.Then an elliptical region of interest(ROI)was designed to extract adjacent tree rows,followed by a two-step tree row segmentation method which classified the data into the left and right tree rows.Finally,the tree line was fitted by the least square method and the center line of the tree row was determined as the navigation path.The virtual orchard environment and LiDAR measurement model were established for the simulation of intra-row navigation.The navigation path was generated based on the simulation measurement data and the vehicle movement was controlled in real-time after using a first-order digital low-pass filter.In the simulation experiments,the planting deviation of fruit tree was set to be±20 cm,the deviation of trunk diameter was±3 cm,and the measurement error of LiDAR was±3 cm.Experimental results showed that the proposed method can extract the navigation path accurately in the case of vehicle yaw,missing tree and curve tree row.When the yaw angle was not more than 15°,the lateral deviation was not more than 1 m,and the missing tree rate was not more than 25%,the lateral deviation between vehicle track and path centerline can be controlled within±14 cm.
作者
李秋洁
丁旭东
邓贤
LI Qiujie;DING Xudong;DENG Xian(College of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing 210037, China)
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2020年第S02期344-350,共7页
Transactions of the Chinese Society for Agricultural Machinery
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)。
