Device and method for rapidly measuring diameter at breast height of tree

Abstract

The invention belongs to the technical field of tree diameter at breast height rapid measurement, and particularly relates to a tree diameter at breast height rapid measurement device and method.The tree diameter at breast height rapid measurement device comprises a tripod, a leveling mechanism, a first laser range finder and a controller, a base is hinged to the bottom of the tripod, a base is arranged on the top of the tripod, a rotating disc is arranged on the leveling mechanism, and the controller is connected to the rotating disc; the first laser range finder is connected to the controller, the gradienter is connected to the controller, the first laser range finder and the power device are both electrically connected with the controller, and the measurement method mainly adopts laser scanning to obtain distance and angle information and records the position and the diameter at breast height of the tree by using formulas (x, y) = (d2 * sin alpha, d2 * cos alpha) and R = (d1 + d3-2d2) / 2d2. Compared with the prior art, the method has the advantages that the DBH data can be obtained through one-time scanning of the laser range finder, three-dimensional modeling and later data processing do not need to be carried out, and the measurement efficiency and convenience are improved.

Description

Technical Field

[0001] The invention relates to the technical field of rapid measurement of tree diameter at breast height, and in particular to a device and method for rapid measurement of tree diameter at breast height. Background Art

[0002] Rapid measurement of tree diameter at breast height plays a key role in forestry. It can quickly and accurately obtain a large amount of tree diameter at breast height data, providing basic information for forest resource inventory. By measuring the diameter at breast height of trees in different regions, we can understand the tree species composition, forest growth conditions, and structural characteristics of the forest, and then evaluate the quantity and quality of forest resources. It helps to determine the timber volume of the forest. According to the diameter at breast height data and the corresponding volume formula, the volume of the tree can be estimated. It is crucial for the sustainable management of forests. By regularly measuring the diameter at breast height of trees, we can monitor the growth rate and health of trees, and promptly detect trees with abnormal growth so that appropriate nurturing measures can be taken, such as fertilization, pruning, or pest and disease control.

[0003] For a long time, forestry workers mainly use simple tools such as calipers and tape measures to measure the diameter at breast height of trees. These methods are not only cumbersome to operate, but also the measurement accuracy is easily affected by human factors. In large-scale forest resource surveys, traditional methods are inefficient and difficult to meet the needs of quickly obtaining a large amount of data. The application of rapid measurement devices and methods can greatly shorten the measurement time, improve work efficiency, and enable forestry workers to complete more measurement tasks within a limited time. With the continuous advancement of science and technology, the application of electronic technology, sensor technology and information technology in the field of forestry has gradually expanded. The emergence of electronic measuring instruments has made it possible to quickly measure the diameter at breast height of trees. For example, the application of equipment such as laser rangefinders and electronic calipers has improved the accuracy and speed of measurement. At the same time, the development of wireless communication technology and data storage technology has enabled the measurement data to be transmitted and stored in real time, which is convenient for subsequent data analysis and management. At present, the use of emerging technologies for rapid measurement of tree diameter at breast height mainly uses laser scanners, which require 3D scanning of trees, establishment of 3D models, and subsequent internal processing to obtain data. This method still requires later personnel processing and 3D modeling. Therefore, it is necessary to invent a fast and efficient device and method for rapid measurement of diameter at breast height. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention develops a device and method for quickly measuring the diameter at breast height of trees. The diameter at breast height data can be obtained by a single scan with a laser rangefinder, and no three-dimensional modeling and post-data processing are required, thereby improving measurement efficiency and convenience.

[0005] The technical solution to the technical problem solved by the present invention is: a tree breast diameter rapid measurement device, comprising a tripod, a leveling mechanism, a first laser rangefinder and a controller, wherein the bottom of the tripod is hinged with a base, the top of the tripod is provided with a pedestal, the leveling mechanism is provided with a rotating disk, the controller is connected to the rotating disk, the first laser rangefinder is detachably connected to the controller, the controller is connected to a level meter, the rotating disk is driven by a power device, and the first laser rangefinder and the power device are both electrically connected to the controller.

[0006] Preferably, a second laser rangefinder is connected to a side of the base away from the leveling mechanism, a display is provided on the base, and the second laser rangefinder is electrically connected to the display.

[0007] Preferably, the leveling mechanism includes an adjusting seat, an adjusting nut and a bolt, the bolt is threadedly connected to the base, the bolts are arranged in a circular array on the base, one end of the adjusting nut is connected to the bolt, and the other end is rotatably connected to the adjusting seat.

[0008] Preferably, the power device is a servo motor, the servo motor is connected to the adjustment seat through a flange, and the rotating disk is connected to the output end of the servo motor.

[0009] Preferably, the legs of the tripod are telescopic rods, and limiting bolts are provided on the telescopic rods.

[0010] A method for quickly measuring the diameter at breast height of a tree, using the method for quickly measuring the diameter at breast height of a tree to quickly measure the diameter at breast height of a tree, comprising the following steps: Step 1: Open the tripod, support it stably, and perform preliminary leveling; Step 2: Turn on the second laser rangefinder. The display will show the height of the first laser rangefinder based on the height data measured by the second laser rangefinder plus the vertical distance between the first laser rangefinder and the second laser rangefinder. Adjust the first laser rangefinder to 1.3m based on the height displayed on the display. Step 3: Operate the leveling mechanism and adjust the controller and the first laser tester to a level with the level; Step 4: Start the first laser rangefinder, select the initial direction, and input the direction data into the controller. Meanwhile, the controller records the initial point data of the first laser rangefinder, with the initial point as the origin of the plane position coordinate, the initial direction as the y-axis, and the direction perpendicular to the initial direction in the horizontal direction as the x-axis; Step 5: The controller controls the servo motor to start rotating, and the laser rangefinder starts scanning nearby trees. Three data are recorded during the scanning process, namely, the distance data d1 from the first laser rangefinder to the tree when the laser contacts the tree, the minimum value d2 of the distance from the first laser rangefinder to the tree, and the distance data d3 from the first laser rangefinder to the tree when the laser leaves the tree, and the direction data of d2 is recorded at the same time; Step 6: According to d2 and the angle α between d2 and the initial direction, the plane position coordinates of the tree are calculated and recorded in the controller; Step 7: Calculate the tree's breast diameter R based on d1, d2, and d3, and synchronize the breast diameter information to the point corresponding to the tree in the plane position coordinates.

[0011] The leveling operation in step 3 is to rotate the adjusting nut and observe the bubble of the spirit level until the bubble is adjusted to be located in the middle of the spirit level.

[0012] The three data recorded in step 5 are input with a threshold in the controller according to the tree diameter range. The three data within the threshold range can be recorded, and the data outside the threshold will be automatically cleared.

[0013] The method for calculating the plane coordinates in step 6 is to obtain the plane position coordinates (x, y) = (d2*sinα, d2*cosα) based on d2 and the angle α, where the angle α refers to the angle formed by rotating in the same direction in the plane position coordinate system starting from the initial direction.

[0014] The calculation method of the breast diameter R in step 7 is R=(d1²+d3²-2d2²) / 2d2.

[0015] The effects provided in the content of the invention are only the effects of the embodiments, rather than all the effects of the invention. The above technical solution has the following advantages or beneficial effects: 1. The design of the tripod is convenient for rapid deployment and stable support. The legs of the tripod are telescopic rods and are provided with limit bolts. The height of the tripod can be quickly adjusted according to different measurement environments and requirements to adapt to various terrains and measurement conditions, thereby improving the flexibility and adaptability of the device. Through preliminary leveling combined with the leveling mechanism and the level gauge, the measuring device can be adjusted to a horizontal state in a short time, greatly reducing the preparation time before measurement. The cooperation of the second laser rangefinder and the display can quickly and accurately determine the height of the first laser rangefinder without the need for additional measuring tools and complex calculations, further improving the positioning speed of the measuring device. 2. The servo motor drives the rotating disk, so that the first laser rangefinder can quickly scan nearby trees and record a large number of tree data in a short time. And by setting the threshold through the controller, it can automatically filter the valid data and quickly remove the invalid data, which greatly improves the efficiency of data collection; the controller can automatically calculate based on the collected data, such as quickly calculating the plane position coordinates and breast diameter of the tree, without the need for manual complex calculation process, which greatly shortens the time from data collection to obtaining results; 3. For the calculation of the tree's diameter at breast height, a specific formula R= (d1²+d3²-2d2²) / 2d2 is used. This formula is based on multiple key data collected by the laser rangefinder. It can obtain two radius information in two directions respectively. In this way, the diameter at breast height obtained is more accurate and has a small error. 4. For the calculation of the plane position coordinates of trees, the formula (x, y) = (d2*sinα, d2*cosα) is used according to the angle, which can accurately determine the position of the trees in the plane position coordinate system. For trees whose diameter at breast height does not meet the requirements, they can be quickly located, thus improving the efficiency of forestry surveys; 5. The controller used in the present invention can automatically record various data in the measurement process, including the distance data from the laser rangefinder to the tree, direction data, plane position coordinates, etc., and can store these data in the internal memory to facilitate subsequent data query and analysis; the automatic recording and storage function of data avoids the tediousness and errors of manual data recording and improves the reliability and traceability of data. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a front view of the present invention; Figure 2 for Figure 1 A partial enlarged view of the middle A area; Figure 3 The overall structure of the present invention Figure 1 ; Figure 4 for Figure 3 A partial enlarged view of the middle A area; Figure 5 The overall structure of the present invention Figure 2 ; Figure 6 for Figure 5 A partial enlarged view of the middle A area; Figure 7 is a schematic diagram of a plane coordinate system of (x, y) coordinates and angle α; Figure 8 This is the schematic diagram for calculating the breast diameter R.

[0017] Among them: 1. tripod; 101. base; 102. pedestal; 103. limit bolt; 2. adjustment seat; 21. adjustment nut; 22. bolt; 3. first laser rangefinder; 31. servo motor; 32. level; 33. controller; 4. second laser rangefinder; 41. display. DETAILED DESCRIPTION

[0018] In order to clearly illustrate the technical features of the present invention, the present invention is described in detail below through specific implementation methods and in conjunction with the accompanying drawings.

[0019] Example 1 See also Figures 1 to 6 A tree breast diameter rapid measurement device comprises a tripod 1, a leveling mechanism, a first laser rangefinder 3 and a controller 33, wherein the bottom of the tripod 1 is hinged with a base 101, the top of the tripod 1 is provided with a base 102, a rotating disk is provided on the leveling mechanism, the controller 33 is connected to the rotating disk, the first laser rangefinder 3 is detachably connected to the controller 33, the controller 33 is connected with a level 32, the rotating disk is driven by a power device, and the first laser rangefinder 3 and the power device are both electrically connected to the controller 33.

[0020] like Figures 3 to 6 As shown, a second laser rangefinder 4 is connected to a side of the base 102 away from the leveling mechanism, a display 41 is provided on the base 102 , and the second laser rangefinder 4 and the display 41 are electrically connected.

[0021] like Figure 2 , Figure 4 and Figure 6 As shown, the leveling mechanism includes an adjustment seat 2, an adjustment nut 21 and a bolt 22. The bolt 22 is threadedly connected to the base 102. The bolts 22 are arranged in a circular array on the base 102. One end of the adjustment nut 21 is connected to the bolt 22, and the other end is rotatably connected to the adjustment seat 2.

[0022] like Figure 1 and Figure 2 As shown, the power device is a servo motor 31 , which is connected to the adjustment seat 2 via a flange, and the rotating disk is connected to the output end of the servo motor 31 .

[0023] like Figure 1 , Figure 3 and Figure 5 As shown, the legs of the tripod 1 are telescopic rods, and a limiting bolt 103q is provided on the telescopic rod.

[0024] See also Figures 1 to 8A method for quickly measuring the diameter at breast height of a tree is provided. The method for quickly measuring the diameter at breast height of a tree is used to quickly measure the diameter at breast height of a tree, and the method comprises the following steps: Step 1: Open the tripod 1 and place it in a suitable measuring position. Make sure that the three legs of the tripod 1 can be firmly supported on the ground to provide a stable foundation for subsequent measurement work. Then, perform preliminary leveling operations. By observing the level indicator attached to the tripod 1 or using other simple leveling tools, roughly adjust the position of the tripod 1 to make it as close to the horizontal state as possible, creating favorable conditions for the subsequent accurate measurement of the instrument; Step 2: Turn on the second laser rangefinder 4. At this time, the display 41 connected thereto will start working according to the height data measured by the second laser rangefinder 4. The display 41 will add the vertical distance between the first laser rangefinder 3 and the second laser rangefinder 4 to the received height data, and then display the current height of the first laser rangefinder 3. Then, according to the height value on the display 41, the first laser rangefinder 3 is adjusted to a height of 1.3m from the ground by adjusting the tripod 1. This height is the standard height for measuring the tree diameter at breast height in the specification. Step 3: When performing the leveling operation, the adjusting nut 21 needs to be rotated. During this process, attention should be paid to the position change of the bubble in the level 32. By adjusting the rotation angle and direction of the adjusting nut 21, the bubble in the level 32 gradually moves to the middle position, and fine-tuning is continued until the bubble is precisely located in the middle of the level 32. At this time, it indicates that the controller 33 and the first laser tester are in a completely horizontal state; the horizontal adjustment can ensure that the laser emitted by the subsequent laser rangefinder can be accurately scanned and measured in the horizontal direction, avoiding the generation of measurement errors due to the tilt of the instrument; Step 4: Start the first laser rangefinder 3, select the initial direction, and input the direction data into the controller 33. Meanwhile, the controller 33 records the initial point data of the first laser rangefinder 3. The initial point is used as the origin of the plane position coordinate, the initial direction is used as the y-axis, and the direction perpendicular to the initial direction in the horizontal direction is used as the x-axis. Step 5: The controller 33 controls the servo motor 31 to start rotating, thereby driving the first laser rangefinder 3 to start a comprehensive scan of the nearby trees. During the scanning process, the first laser rangefinder 3 will record three key data; first, the distance data d1 from the first laser rangefinder 3 to the tree when the laser contacts the tree, second, the minimum value d2 of the distance from the first laser rangefinder 3 to the tree, and finally, the distance data d3 from the first laser rangefinder 3 to the tree when the laser leaves the tree; at the same time, the direction data of d2, that is, the angle between the direction of d2 and the initial direction, will also be recorded. In order to ensure the validity and accuracy of the recorded data, a reasonable threshold value is pre-entered in the controller 33 according to the approximate range of the tree's diameter at breast height. Only the three data within this threshold range can be effectively recorded, and those data outside the threshold will be automatically cleared by the controller 33 to avoid invalid data from interfering with subsequent calculations and analysis. For example, by observing that the tree diameter at breast height is about 20 cm, the threshold can be set to the range of 10-15 cm. Only a group of three data less than this threshold will be recorded. If the difference in the tree diameter at breast height is large, a larger threshold can be set; Step 6: Calculate the plane position coordinates of the tree according to d2 and the angle α between d2 and the initial direction and record them in the controller 33; According to the recorded d2 data and the angle α between d2 and the initial direction, the plane position coordinates of the tree are calculated using the formula (x, y) = (d2*sinα, d2*cosα), wherein the angle α refers to the angle formed by rotating in the same direction (clockwise or counterclockwise) in the plane position coordinate system starting from the initial direction. The specific position coordinates of the tree in the plane rectangular coordinate system are obtained through calculation and recorded in detail in the controller 33. This operation enables each tree to have a clear position identification in the plane position coordinate system, providing important position information for subsequent data analysis and processing; Step 7: Calculate the tree's breast diameter R based on d1, d2, and d3, and synchronize the breast diameter information to the point corresponding to the tree in the plane position coordinates.

[0025] According to d1, d2 and d3, using a point outside the circle to draw a tangent to the circle will result in a right triangle, and one of the right-angled sides of the right triangle is the radius of the circle. The formula R=(d1²+d3²-2d2²) / 2d2 is used to accurately calculate the tree's breast diameter R. After obtaining the exact value of the tree's breast diameter, this breast diameter information is synchronized to the corresponding point of the tree in the plane position coordinates. In this way, not only can we intuitively understand the breast diameter of each tree, but we can also closely link the breast diameter information with the tree's location information, providing comprehensive and accurate data support for subsequent tree resource management, research and planning.

[0026] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Based on the technical solution of the present invention, various modifications or variations that can be made by those skilled in the art without creative work are still within the scope of protection of the present invention.

Claims

1. A tree diameter at breast height rapid measurement device, characterized in that: The invention comprises a tripod (1), a leveling mechanism, a first laser rangefinder (3) and a controller (33); the bottom of the tripod (1) is hingedly connected to a base (101); the top of the tripod (1) is provided with a pedestal (102); the leveling mechanism is provided with a rotating disk; the controller (33) is connected to the rotating disk; the first laser rangefinder (3) is detachably connected to the controller (33); the controller (33) is connected to a level (32); the rotating disk is driven by a power device; and the first laser rangefinder (3) and the power device are both electrically connected to the controller (33).

2. A tree diameter at breast height rapid measurement device according to claim 1, characterized in that: A second laser rangefinder (4) is connected to a side of the base (102) away from the leveling mechanism, a display (41) is provided on the base (102), and the second laser rangefinder (4) and the display (41) are electrically connected.

3. A tree diameter at breast height rapid measurement device according to claim 2, characterized in that: The leveling mechanism comprises an adjustment seat (2), an adjustment nut (21) and a bolt (22); the bolt (22) is threadedly connected to the base (102); the bolts (22) are arranged in a circular array on the base (102); one end of the adjustment nut (21) is connected to the bolt (22) and the other end is rotationally connected to the adjustment seat (2).

4. A tree diameter at breast height rapid measurement device according to claim 3, characterized in that: The power device is a servo motor (31), the servo motor (31) is connected to the adjustment seat (2) via a flange, and the rotating disk is connected to the output end of the servo motor (31).

5. The tree diameter at breast height rapid measurement device according to claim 1, characterized in that: The legs of the tripod (1) are telescopic rods, and the telescopic rods are provided with limit bolts (103).

6. A method for quickly measuring the diameter at breast height of a tree, characterized in that: The method for quickly measuring the tree diameter at breast height described in claim 4 is used to quickly measure the tree diameter at breast height, comprising the following steps: Step 1: Open the tripod (1), stabilize it, and perform preliminary leveling. Step 2: Turn on the second laser rangefinder (4), and the display (41) displays the height of the first laser rangefinder (3) based on the height data measured by the second laser rangefinder (4) and the vertical distance between the first laser rangefinder (3) and the second laser rangefinder (4). The first laser rangefinder (3) is adjusted to 1.3 m based on the height displayed on the display (41); Step 3: operate the leveling mechanism and adjust the controller (33) and the first laser tester to a level with the help of a level gauge; Step 4: Start the first laser rangefinder (3), select an initial direction, and input the direction data into the controller (33), while the controller (33) records the initial point data of the first laser rangefinder (3), the initial point is used as the origin of the plane position coordinate, the initial direction is used as the y-axis, and the direction perpendicular to the initial direction in the horizontal direction is used as the x-axis; Step 5: The controller (33) controls the servo motor (31) to start rotating, and the laser rangefinder starts scanning nearby trees. During the scanning process, three data are recorded, namely, the distance data d1 from the first laser rangefinder (3) to the tree when the laser contacts the tree, the minimum value d2 of the distance from the first laser rangefinder (3) to the tree, and the distance data d3 from the first laser rangefinder (3) to the tree when the laser leaves the tree, and the direction data d2 is recorded at the same time; Step 6: According to d2 and the angle α between d2 and the initial direction, the plane position coordinates of the tree are calculated and recorded in the controller (33); Step 7: Calculate the tree's breast diameter R based on d1, d2, and d3, and synchronize the breast diameter information to the point corresponding to the tree in the plane position coordinates.

7. The method for rapid measurement of tree diameter at breast height according to claim 6, characterized in that: The leveling operation in step 3 is to rotate the adjustment nut (21) and observe the bubble of the level (32) until the bubble is adjusted to be located in the middle of the level (32).

8. The method for rapid measurement of tree diameter at breast height according to claim 6, characterized in that: The three data recorded in step 5 are input with a threshold value in the controller (33) according to the range of the tree diameter at breast height. The three data within the threshold value can be recorded, and the data outside the threshold value will be automatically cleared.

9. The method for rapid measurement of tree diameter at breast height according to claim 6, characterized in that: The method for calculating the plane coordinates in step 6 is to obtain the plane position coordinates (x, y) = (d2*sinα, d2*cosα) based on d2 and the angle α, where the angle α refers to the angle formed by rotating in the same direction in the plane position coordinate system starting from the initial direction.

10. The method for rapid measurement of tree diameter at breast height according to claim 6, characterized in that: The calculation method of the breast diameter R in step 7 is R=(d1²+d3²-2d2²) / 2d2.

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