基于多层K-means在森林点云中的单木识别算法

doi:10.13466/j.cnki.lyzygl.2022.01.015

摘要/Abstract

摘要：

针对目前激光雷达(Light Detection And Ranging,LIDAR)采集的森林点云数据使用K-means算法进行单木识别时,算法的收敛时间长,以及对于株树密度大的森林场景容易产生过聚类的问题,提出了一种改进的多层K-means单木识别算法。以黑龙江省佳木斯市孟家岗林场落叶松人工林的点云数据为实验对象,通过RANSAC算法和半径离群值算法去除数据中的地面点与非树干且非地面点,最后通过多层K-means算法进行单木的识别。结果表明,改进后的多层K-means算法单木识别的识别率达到了91.01%,误判树木的数量为0,算法收敛时间相较于传统K-means算法缩短了48.13%。可以得出结论,多层K-means算法效率更高,对复杂密集的林分样地进行单木识别有更好的效果,降低了勘测森林结构的成本,这对于森林结构参数的测算、森林资源的保护与总体规划工作有重要意义。

关键词: 森林结构, 点云数据, K-means算法, 单木识别, 激光雷达

Abstract:

When the K-means algorithm is used for single tree recognition for the forest point cloud data collected by the current Lidar (Light Detection And Ranging,LIDAR),the algorithm has a long convergence time and is prone to clustering for forest scenes with high density of trees. An improved multi-layer K-means single tree recognition algorithm was proposed.Taking the point cloud data of the Larix olgensis plantation in Mengjiagang Forest Farm in Jiamusi City,Heilongjiang Province as the experimental object,the RANSAC algorithm and radius outlier denoising algorithm were used to remove ground points and non-trunk and non-ground points in the data.Finally,the single tree recognition was carried out through the multi-layer K-means algorithm.The results showed that the improved multi-layer K-means algorithm had a single tree recognition accuracy rate of 91.01% and the false calculation amount of the trees was 0.Compared with the traditional K-means algorithm,the convergence time of the algorithm was shortened by 48.13%.It can be concluded that the multi-layer K-means algorithm is more efficient,and single tree identification in complex and dense forest plots has better results.The cost of surveying forest structure is reduced,which is of great significance to the calculation of forest structure parameters,the protection of forest resources and the overall planning.

Key words: forest structure, point cloud data, K-means algorithm, single tree recognition, Light Detection And Ranging

中图分类号:

S758

谷志新, 裴方睿. 基于多层K-means在森林点云中的单木识别算法[J]. 林业资源管理, 2022,(1): 124-131.

GU Zhixin, PEI Fangrui. Single Tree Recognition Algorithm Based on Multi-Layer K-means in Forest Point Cloud[J]. FOREST RESOURCES WANAGEMENT, 2022,(1): 124-131.

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参数名称	数值
绝对精度	3cm
相对精度	5cm
扫描距离	100m
水平视场角	360°
垂直视场角	180°(-90°~90°)

层数/层	聚类后包含的点/个
2	5362
3	7512
4	7730
5	8925
6	8620
7	7759
8	6623

层数/层	识别率/%	层数/层	识别率/%
2	86.37	6	91.01
3	89.99	7	91.37
4	91.01	8	89.68
5	91.01

单木识别方法	单木总数/株	识别率/%
多层K-means	649	91.01
单层K-means	649	86.37