林业科学2026，Vol.62Issue(2)：186-203,18.DOI:10.11707/j.1001-7488.LYKX20240671
基于点云建模的核桃树振动参数优化与试验
Optimisation and Testing of Vibration Parameters of Walnut Trees Based on Point Cloud Modelling
摘要
Abstract
[Objective]This study aims to investigate the forced-vibration responses of walnut trees with different sizes,and to address the problems of low efficiency and a low fruit removal rate in vibratory walnut harvesting.[Method]A terrestrial 3D laser scanner was used to acquire point-cloud data of walnut trees.After preprocessing the tree point clouds,tree skeletons were extracted.Siemens NX was employed to perform 3D fitting and reconstruction,and 3D walnut-tree models with different size parameters were established.Material-property parameters were calibrated using measured frequency spectra,and the maximum relative error of resonance frequencies observed in both experiments and simulations was only 0.22%,ensuring the accuracy of the 3D models.ANSYS was used to conduct harmonic response analyses on the 3D model of walnut trees,to investigate the effects of excitation frequency,excitation force,and excitation height on vibration acceleration,and to analyze the displacement and acceleration responses of walnut trees with different sizes under different frequencies.In addition,suitable harvesting frequencies for walnut trees of different sizes were further determined by integrating the displacement and acceleration responses of fruiting branches with the whole-tree responses shown in harmonic-response contour plots.[Result]The peak acceleration response decreased with increasing trunk diameter,tree height,and crown width.Higher trees and larger crowns exhibited weaker responses to high-frequency excitation,indicating that the geometric characteristics of the tree significantly affect its vibration characteristics.The vibration harvesting parameters of walnut trees were subjected to the response surface analysis and optimized to obtain an optimal parameter combination.Under the optimal excitation conditions,the walnut harvesting rate exceeded 90%for all tested trees,indicating that the optimised vibration parameters can provide guidance for parameter settings of vibratory walnut-harvesting devices.[Conclusion]The walnut-tree modelling method described in this study enables reconstruction of fine lateral branches,and the reconstructed whole-tree models better capture realistic growth morphology.Walnut trees with different trunk diameters,heights,and crown widths show distinct vibration responses.The suitable excitation frequency range is 10-20 Hz,which can be further narrowed according to specific tree-structure parameters.关键词
核桃收获/振动采收/有限元分析/振动响应/响应面分析/激振频率优化Key words
walnut harvesting/vibratory harvesting/finite element analysis/vibration response/response surface analysis/excitation frequency optimisation分类
农业科技引用本文复制引用
崔王斌,周宏平,张洋,王艳艳,许林云,范高鸣..基于点云建模的核桃树振动参数优化与试验[J].林业科学,2026,62(2):186-203,18.基金项目
"十四五"国家重点研发计划项目(2022YFD2202105-2). （2022YFD2202105-2）
