Standing wood diameter detection device based on laser and visual technology

Abstract

The invention discloses a standing wood diameter detection device based on laser and visual technology. After collimating beam expanding, laser beams are irradiated onto a tree trunk (1) of which the tree diameter is required to be measured; the image of the tree trunk, at a position where a laser spot is positioned, is shot by using a video camera (15); the distances between the upper side of the laser spot on the tree trunk and laser emitting equipment and between the lower side of the laser spot on the tree trunk and the laser emitting equipment are measured by using laser range finders (7) and (9); the practical size of the laser spot is calculated according to a distance difference; and the tree diameter is measured according to the pixels of the laser spot in the image by taking the practical size of the laser spot as a measuring scale.

Description

technical field [0001] The invention belongs to the field of machine vision technology and tree detection technology, and in particular relates to a device for quickly detecting tree diameters by using laser ranging and machine vision technology. Background technique [0002] Machine vision is a comprehensive technology that integrates digital image processing, machinery, control, optics, computer and other technologies. The machine vision system can realize non-contact detection of the target, can quickly obtain a large amount of information, and is easy to process automatically. Wide range of applications. [0003] In forest resources investigation, the measurement of tree diameter is a very important content. When measuring the diameter of a single standing tree in China, most of them rely on the operator to measure the circumference of the tree with a tape measure, and then calculate the diameter of the tree, or use the same method of marking the scale on the ruler acc...

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Problems solved by technology

[0004] The School of Mechanical Engineering, Huazhong University of Science and Technology proposed a method of calibrating the camera with a measuring scale for measurement (Song Xiaochun, Kang Yihua, etc., Research on Forest Automatic Measurement System Based on Digital Image Processing, Computer Engineering and Design, 2005, 26(5): 1187- 1189.), the disadvantage of this method is that when measuring each tree, a ruler needs to be placed at the trunk to be measured, and the efficiency is relatively low, and some trees that cannot be approached in mountainous areas and the side trunks at the height of trees cannot place rulers ,not measurable

However, in actual measurement, it cannot be guaranteed that the laser beam is perpendicular to the trunk, especially when the trunk is tilted, the size of the laser spot irradiated on the trunk will change greatly, and it is impossible to determine the actual size of the laser spot on the trunk at this time. In this case, the detected diameter of the standing tree will produce a large error, and the larger the inclination angle of the standing tree, the greater the detection error, causing this detection method to fail

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