一种基于点云自适应切片的树冠体积计算方法  

A Tree Crown Volume Calculation Method Based on Adaptive Slice of Point Cloud

作　　者：周恒可 李海旺 赵兴 郭彩玲[2] 李柏林[3] ZHOU Heng-ke;LI Hai-wang;ZHAO Xing;GUO Cai-ling;LI Bai-lin(Graduate School of Tangshan,SouthwestJiaotong University,Tangshan 063000,Hebei,China;Tangshan University,Key Lab of Intelligent Equipment Digital Design and Process Simulation,Tangshan 063000,Hebei,China;School of Mechanical Engineering,SouthwestJiaotong University,Chengdu 610031,Sichuan,China)

机构地区：[1]西南交通大学唐山研究院,河北唐山063000 [2]唐山学院河北省智能装备数字化设计及过程仿真重点实验室,河北唐山063000 [3]西南交通大学机械工程学院,四川成都610031

出　　处：《西北林学院学报》2023年第6期189-195,202,共8页Journal of Northwest Forestry University

基　　金：河北省高层次人才项目(A202001095);河北省科技厅重点研发计划(20327107D)。

摘　　要：无人机精准施药有利于节约药液,减少环境污染。针对无人机精准施药中树冠体积计算粗略的问题,提出一种基于点云自适应切片的树冠体积计算方法。首先对树木点云数据进行等间距切片;然后根据相邻树冠点云切片的面积随高度的变化率自适应分层,使用改进的Graham凸包算法计算自适应分层前后树冠点云切片面积;最后基于台体与锥体公式累加各层树冠点云之间的体积求得整个树冠的体积。试验结果表明,研究方法确保了树冠点云切片厚度和数量与树冠自身的形状和大小相适应,同时有效缩小树冠点云切片边界空隙,得到较为准确的树冠点云切片面积,进而实现了树冠体积的精细化计算。其计算结果介于Graham凸包算法和体元法之间,在精度方面分别提高了30.89%和24.19%,可科学地为无人机施药过程中精准施药策略提供理论依据。Precise application of pesticides by UAV is conducive to saving chemicals and reducing environmental pollution.Aiming at the problem of low accuracy of canopy volume calculation in UAV precision application,this research proposed a method based on point cloud adaptive slicing to improve the calculation accuracy.Firstly,equidistant spacing was performed on the tree point cloud data.Then,according to the area of adjacent canopy point cloud slices with the change rate of height,the improved Graham convex hull algorithm was used to calculate the area of canopy point cloud slices before and after adaptive stratification.Finally,the volume of the entire canopy was obtained by accumulating the volume between the canopy point clouds of each layer based on the formula of table and cone.The experimental results showed that this method ensured that the thickness and number of canopy point cloud slices were suitable for the shape and size of the canopy itself,and at the same time effectively narrowed the boundary gap of canopy point cloud slices,and obtained a more accurate canopy point cloud slice area,and then realized the fine calculation of canopy volume.The calculation results were between those of Graham convex hull algorithm and voxel method,and the accuracy improved by 30.89%and 24.19%,respectively compared to the two methods.The proposed method can scientifically provide a theoretical basis for the precise application strategy in the process of UAV application.

关 键 词：点云 切片自适应 Graham凸包算法 边界提取 树冠体积 

分 类 号：P234[天文地球—摄影测量与遥感]