Authors

Abstract

In order to solve the problem of complicated processes, low efficiency and high cost of economic tree trunks girdling, inspired by cam mechanism this study developed a new type of automatic half-ring girdling device, which can automatically complete a series of operations, including the tree trunk profile scanning, girdling trajectory calculating and automatic bark cutting. A pair of laser rangefinders and guide screws were symmetrically arranged on a half-ring rotating rail, which could rotate around the tree trunk, and two chainsaws assembled above the guide screws were controlled to move radially. The laptop was used as upper computer, and a 4-axis motion control card was used as the lower computer, which constituted the control system of precise movement. The programs of the tree trunk profile scanning, the xylem profile curve fitting and the chainsaw centre trajectory calculation were designed in LabVIEW. The scanning tests and girdling experiments were carried out on the different sections of the tree trunks in the laboratory. The feasibility of the automatic girdling device for economic tree trunks was verified with one complete and automatic girdling operation finished by this device, which took 150 seconds, and the error range of automatic girdling was within ±2mm. This device improves the automation degree of girdling operation and provides a support for the development of economic forestry.

Abstract in Chinese

为解决经济林树木开甲存在流程复杂，效率低，成本高的问题，受凸轮原理启发，本文设计一种新型自动化半环开甲装置，自动完成树干轮廓扫描，环剥轨迹计算，自动切割树皮等操作。该装置在半环转动支架上对称安装了一对称双激光测距仪、丝杠，半环支架可环绕树干旋转运动。丝杠上面安装的手持电锯能够实现径向运动。以LabVIEW为上位机，以4轴运动控制卡作为下位机，构成精确运动的控制系统。在LabVIEW中完成了树干轮廓扫描、木质部轮廓曲线拟合、电锯中心轨迹计算等程序设计。在实验室中对树干不同的截面进行了测量实验和环剥实验。完整自动的开甲操作证实了该经济林开甲装置的可行性，该装置单次自动环剥时间为150秒，开甲精度为±2mm。该装置提高了开甲操作的自动化程度，为经济林产业提供了支撑。