基于无人机LiDAR的农田平整地势测量方法

Farmland Leveling Topography Measurement Method Based on UAV LiDAR

为了提高农田平整作业中地势测量速度与精度,本文提出一种基于无人机LiDAR的农田平整地势测量方法。通过无人机搭载LiDAR测量系统,获取高精度农田地势点云数据。对采集的点云数据进行预处理,通过直通滤波方法去除z轴方向上的大量噪点。使用渐进式形态学滤波算法,分割农田地面点与非地面点。在保留主要农田地势信息特征的基础上,使用基于VoxelGrid滤波器的农田地势点云精简方法对农田地势点云数据进行精简。在4块不同面积的农田中,分别使用无人机LiDAR测量方式与全球导航卫星系统(GNSS)测量方式进行地势测量试验,试验结果表明,与GNSS测量真值的平整度相比,其准确度分别为94.681%、91.364%、90.588%和90.287%,与GNSS测量真值的最大高程差相比,其准确度分别为99.391%、98.167%、97.025%和98.776%,与GNSS测量真值的高差分布列相比,其准确度分别为99.307%、97.914%、98.673%和95.110%。本文提出的基于无人机LiDAR的农田地势测量方法可快速精准测量农田地势信息,可为下一步农田平整作业提供数据支持。

In order to improve the speed and accuracy of terrain measurement in farmland leveling operation,a method of farmland leveling terrain measurement was proposed based on UAV LiDAR.Firstly,high-precision farmland terrain point cloud data was obtained by using LiDAR measurement system equipped with UAV.After preprocessing the collected point cloud data,a large number of noise points along the z-axis were removed by direct filtering.Then,the progressive morphological filtering algorithm was used to segment farmland surface points and non surface points.Finally,on the basis of retaining the main farmland terrain information features,the farmland terrain point cloud reduction method based on VoxelGrid filter was used to simplify the farmland terrain point cloud data.The results showed that compared with the flatness of GNSS,the accuracy was 94.681%,91.364%,90.588%and 90.287%respectively;compared with the maximum elevation difference of GNSS,the accuracy was 99.391%,98.167%,97.025%and 98.776%respectively.Compared with the height difference distribution of GNSS,the accuracy was 99.307%,97.914%,98.673%and 95.110%respectively.The farmland terrain measurement method proposed based on UAV LiDAR can quickly and accurately measure the farmland terrain information,and provide data support for the next farmland leveling operation.