Forestry measurement device and method

Abstract

The invention discloses a forestry measuring device and method, and belongs to the technical field of forestry machinery and measuring tools. The device comprises a supporting assembly, a vertical lifting assembly, a limiting frame body, a measuring assembly and a connecting assembly. The limiting frame body is formed by rotationally connecting a first limiting frame and a second limiting frame through a pin shaft and can be spliced into a circular ring with the diameter larger than the diameter at breast height of a tree. The measuring assembly comprises a telescopic ruler with scales and a walking wheel and is arranged on the limiting frame in a sliding mode. The connecting assembly is used for connecting and fixing the measuring assemblies on the two sides to ensure that the connecting line coincides with the diameter of the ring. The device can rapidly and stably surround a tree trunk, accurately calculates the diameter at breast height of the tree through the expansion and contraction amount of the telescopic ruler, effectively overcomes the problems of personal error, assumed circular cross section, single-point measurement and the like in the measurement of the traditional surrounding ruler and caliper, and has the advantages of accurate measurement, simplicity and convenience in operation, strong adaptability and the like; the method is suitable for fields of forestry resource investigation and tree growth monitoring.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of forestry machinery and measuring tools, in particular to a forestry measuring device and method. BACKGROUND

[0002] Forestry refers to the production department of protecting the ecological environment and maintaining the ecological balance, cultivating and protecting forests to obtain wood and other forest products, and utilizing the natural characteristics of trees to play a protective role. Forestry is one of the important components of the national economy. The forestry department has a special statistical department to conduct statistics on the circumference of trees, the diameter of trees, and the height of trees.

[0003] Periodically measuring the diameter at breast height or circumference of trees is like a regular physical examination for trees. The main purpose is to accurately assess the growth rate and health of trees. By analyzing measurement data at different times, it can be determined whether trees are suffering from diseases, pests, soil problems, or environmental stress, and provide key basic data for forestry management, scientific research, and urban greening planning, thereby supporting timely maintenance intervention and long-term resource management decisions.

[0004] Currently, the most commonly used diameter at breast height measuring tools are diameter at breast height tape and tree calipers. Diameter at breast height tape measures the diameter by measuring the circumference, assuming that the cross section of the trunk is a standard circle, which will produce significant errors for oval or irregular trunks, and the tightness is measured entirely by hand feeling, introducing human error. Tree calipers measure the diameter at breast height by attaching two rulers to the two sides of the tree. This method can only obtain a diameter value in one direction. In order to ensure the accuracy of the measurement, multiple measurements in different directions are usually required. However, the measurements in different directions cannot be guaranteed to be on the same horizontal plane, resulting in insufficient accuracy of the measurement results. SUMMARY

[0005] The purpose of the present application is to overcome the problems in the prior art and provide a forestry measuring device.

[0006] The present application provides a forestry measuring device, which comprises a support assembly and a vertical lifting assembly arranged on the support assembly, and further comprises a limiting frame body, including a first limiting frame and a second limiting frame, the first limiting frame is fixedly installed on the lifting end of the vertical lifting assembly, the second limiting frame is rotatably connected with the vertical lifting assembly through a pin shaft, and the first limiting frame and the second limiting frame form a complete ring when they are combined together; a measuring assembly, including a telescopic ruler and a walking wheel, the telescopic ruler is arranged on the first limiting frame and the second limiting frame through a pair of arc-shaped sliding blocks, and a pair of telescopic rulers are installed with walking wheels at the telescopic ends. A connecting assembly is detachably connected to the outer side of a pair of arc-shaped sliding blocks, and a pair of telescopic rulers are located on the same straight line when connected, and are arranged along the diameter of the ring.

[0007] Preferably, the telescopic ruler comprises a first ruler body and a second ruler body, the first ruler body is internally provided with a cavity, the second ruler body is slidingly inserted into the first ruler body, a reset spring is arranged in the cavity, one end of the reset spring is fixedly connected with the first ruler body, and the other end is fixedly connected with the second ruler body, the second ruler body is provided with scale lines, and one end connected with the walking wheel is a zero scale end.

[0008] Preferably, the first limiting frame and the second limiting frame are both provided with an arc-shaped through slot, and a pair of arc-shaped sliding blocks are slidingly arranged in the arc-shaped through slots of the first limiting frame and the second limiting frame respectively.

[0009] Preferably, the connecting assembly comprises a connecting frame, a connecting barrel and a threaded column, the connecting frame comprises a first connecting rod and a pair of second connecting rods, the pair of second connecting rods are respectively fixedly connected with the two ends of the first connecting rod perpendicularly, a threaded line is arranged at the end of the second connecting rod away from the first connecting rod, the top end of the connecting barrel is matched with the threaded line, the threaded column is rotationally connected with the first ruler body, the bottom end of the connecting barrel is threadedly sleeved on the threaded column, the second connecting rod is perpendicular to the first ruler body, the length of the first connecting rod is greater than the diameter of the circular ring, and the length of the second connecting rod is greater than the radius of the circular ring.

[0010] Preferably, the supporting assembly comprises a supporting seat and a limiting anchor rod, and the vertical lifting assembly is vertically fixedly connected with the top of the supporting seat, and the bottom of the supporting seat is fixedly connected with the limiting anchor rod.

[0011] Preferably, the vertical lifting assembly comprises a concave frame, a lifting block and a threaded rod, the concave frame is vertically fixedly connected with the supporting seat, the threaded rod penetrates through the concave frame along the length direction of the concave frame and is rotationally connected with the concave frame, the lifting block is threadedly sleeved on one end of the threaded rod and is slidingly connected with the concave frame, a rotating handle is fixedly connected with the top end of the threaded rod and penetrates through the concave frame, an arc-shaped surface is arranged on the side of the lifting block close to the first limiting frame, one end of the first limiting frame is fixedly connected with the lifting block, and the other end is provided with a slot, one end of the second limiting frame is connected with the lifting block through a pin shaft, and the other end is fixedly connected with an insertion block matched with the slot.

[0012] Preferably, an identification line is arranged on the outer side of the concave frame in the vertical direction, a through slot is arranged in the concave frame in the vertical direction, and an identification rod is fixedly connected with the lifting block.

[0013] Preferably, a supporting rod is fixedly connected with the top of the concave frame, an inclined supporting plate is fixedly connected with the top end of the supporting rod, a storage slot is arranged in the supporting plate, and a data processing piece is arranged in the storage slot.

[0014] Preferably, a pair of shoulder straps are arranged on the side of the concave frame away from the lifting block.

[0015] Preferably, a method for using the forestry measuring device is provided. manually holding and rotating the second limiting frame to rotate relative to the vertical lifting assembly around the pin shaft, so as to separate the first limiting frame and the second limiting frame from each other to form an open ring structure; then moving the forestry measuring device to the vicinity of the tree to be measured, operating the supporting assembly to stably place on the ground, ensuring that the device is horizontal and stable; manually operating the vertical lifting assembly to adjust the height of the lifting end to correspond to the standard breast height measuring height of the tree to be measured; At this time, the tree trunk is located in the center area of the to-be-formed ring, and then the second limiting frame is reversely rotated to gradually approach and finally match with the first limiting frame, forming a complete ring structure surrounding the trunk; ensuring that the diameter of the matched ring is greater than the diameter of the tree to be measured, so that the trunk does not contact the inner wall of the ring; A pair of the telescopic rulers are fastened and connected through the connecting assembly, and are arranged along the diameter of the ring, and the first limiting frame and the second limiting frame are ensured to be in a stable matched state during measurement; The telescopic rulers are pressed and the walking wheels are in contact with the surface of the tree to be measured, and after the device is kept stable and all the walking wheels are in stable contact with the trunk, data reading is performed; since the telescopic rulers can be telescoped with the change of the trunk circumference, the scale value displayed on each telescopic ruler is read to obtain the extension length of each measuring point relative to the initial zero position, and since the diameter of the ring, the initial length of the telescopic ruler and the diameter of the walking wheel are fixed values, the length of the measuring ruler located on the first limiting frame and the second limiting frame and the length of the walking wheel are subtracted from the diameter of the ring to obtain the breast height of the tree to be measured; the connecting assembly is pulled to make a pair of the walking wheels roll on the surface of the tree to be measured, and different positions of the tree to be measured in the same plane are measured to ensure the measurement accuracy.

[0016] Compared with the prior art, the forestry measuring device has the following beneficial effects: By setting the ring type limiting frame body composed of the first limiting frame and the second limiting frame, combined with the slidable measuring assembly and the connecting assembly, a forestry measuring device with reasonable structure and convenient operation is provided, which significantly improves the accuracy and reliability of measurement. The limiting frame body ensures that the device maintains a constant relative position with the tree trunk during measurement. The rotating connecting assembly allows the measuring assembly to measure at different positions in the same horizontal plane, adapting to different positions and obtaining multiple sets of measurement data, improving detection accuracy and avoiding errors caused by uneven human force or single-point measurement of the traditional perimeter ruler. It is especially suitable for measuring irregular cross-section trees and improving the accuracy of measurement results. The vertical lifting assembly can adapt to trees with different breast diameters and ground conditions, and the operator can quickly adjust the measurement height and position, reducing repeated handling and setting time. The connecting assembly ensures that the connecting line of the pair of telescopic rulers is always arranged along the diameter of the ring, and the sliding design of the measuring assembly allows multiple data collection, further improving data representativeness. The overall structure has functionality and practicality, and can be used stably in complex forest environments, providing reliable technical support for forestry resource investigation and tree growth monitoring. BRIEF DESCRIPTION OF DRAWINGS

[0017] Fig. 1 It is a schematic diagram of the overall structure of the present application.

[0018] Fig. 2 It is a schematic diagram of the limiting frame body and measuring assembly structure of the present application.

[0019] Fig. 3 It is a schematic diagram of the vertical lifting assembly structure of the present application.

[0020] Fig. 4 It is a schematic diagram of the identification line and identification rod structure of the present application.

[0021] Fig. 5 It is a schematic diagram of the telescopic ruler structure of the present application.

[0022] Fig. 6 It is a schematic diagram of the slot and plug-in block cooperation structure of the present application.

[0023] Explanation of reference signs: 1, support assembly; 101, support seat; 102, limiting anchor rod; 2, vertical lifting assembly; 21, concave frame; 22, lifting block; 23, threaded rod; 24, rotating handle; 3, limiting frame body; 31, first limiting frame; 32, second limiting frame; 4, measuring assembly; 41, telescopic ruler; 411, first ruler body; 412, second ruler body; 413, return spring; 414, scale line; 42, walking wheel; 5, connecting assembly; 51, connecting frame; 511, first connecting rod; 512, second connecting rod; 52, connecting cylinder; 53, threaded column; 6, arc-shaped through slot; 7, arc-shaped sliding block; 8, marking line; 9, marking rod; 10, insertion slot; 11, pin shaft; 12, insertion block; 13, shoulder strap. DETAILED DESCRIPTION

[0024] The technical solutions of the embodiments of the present application will be described clearly and completely below with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the described embodiments of the present application, all other embodiments obtained by those skilled in the art without any creative effort fall within the scope of protection of the present application, unless otherwise defined. The technical terms or scientific terms used in the patent application specification and claims of the present application should be understood as the common meanings by those skilled in the art. Figs. 1-6 The terms "first", "second", and similar terms used in the patent application specification and claims of the present application do not represent any order, number, or importance, but are only used to distinguish different components, and the terms "comprise" or "include" and similar terms mean that the elements or objects before the terms cover the elements or objects listed after the terms and their equivalents, without excluding other elements or objects. "In", "out", "up", "down", "far", "near", "front", "back", and the like are only used to represent relative positional relationships, and when the absolute positions of the described objects change, the relative positional relationships may also change accordingly. The drawings in the present application are not strictly drawn according to the actual proportions, and the specific sizes and quantities of the structures can be determined according to actual needs. The drawings described in the present application are only structural schematic diagrams.

[0025]

[0026] ​Current forestry measurement mainly relies on two types of tools: diameter tape and tree caliper. Diameter tape is based on the principle of circumference-diameter conversion, which has a fundamental defect in its theoretical assumption: it requires the trunk cross-section to be a standard circle. However, under natural growth conditions, most tree cross-sections are elliptical or irregular, resulting in a large systematic error. More seriously, the tightness of the diameter tape during measurement completely depends on the operator's sense of touch, and the data measured by different operators can differ by up to 3 cm, which seriously affects the comparability of forestry census data. Although tree caliper can directly read the diameter value, its single-point measurement mode has the problem of insufficient representation. To obtain reliable data, the operator needs to measure 3-4 times in different directions, but it is difficult to ensure that each measurement is at the same height. Studies have shown that a 5 cm fluctuation in the 1.3 m diameter position will result in a 0.5 cm-1.2 cm deviation in diameter measurement. This height control problem makes the data quality highly dependent on the operator's experience level.

[0027] In the existing measurement process, data recording is still mainly manual, which is prone to transcription errors or omissions. More seriously, due to the lack of reliable positioning reference, it is difficult to measure at the same position during subsequent review, which greatly reduces the continuity of growth monitoring data. This discrete data collection mode of "one measurement one result" cannot form a reliable tree growth curve.

[0028] The present application provides a forestry measurement device, as shown in Figs. 1-3 The device includes a support assembly 1, a vertical lifting assembly 2 arranged on the support assembly 1, a limiting frame 3 including a first limiting frame 31 and a second limiting frame 32, the first limiting frame 31 being fixedly installed on the lifting end of the vertical lifting assembly 2, the second limiting frame 32 being rotatably connected to the vertical lifting assembly 2 through a pin shaft 11, and the first limiting frame 31 and the second limiting frame 32 forming a complete ring when they are combined; a measurement assembly 4 including a telescopic ruler 41 and a walking wheel 42, the telescopic ruler 41 being arranged on the first limiting frame 31 and the second limiting frame 32 through a pair of arc-shaped sliding blocks 7, and the telescopic end of the telescopic ruler 41 being provided with the walking wheel 42; and a connecting assembly 5 being detachably connected to the outer side of the pair of arc-shaped sliding blocks 7, and the pair of telescopic rulers 41 being arranged on the same straight line and along the diameter of the ring when connected.

[0029] In this embodiment, by setting the circular limiting frame body 3 composed of the first limiting frame 31 and the second limiting frame 32, combined with the slidable measurement assembly 4 and the connecting assembly 5, a forestry measurement device with reasonable structure and convenient operation is provided, which significantly improves the accuracy and reliability of measurement. The limiting frame body 3 ensures that the device maintains a constant relative position with the tree trunk during measurement, avoiding errors caused by uneven human force or single-point measurement of the traditional perimeter ruler. It is especially suitable for the measurement of irregular cross-section trees. It improves the measurement efficiency and adaptability. The vertical lifting assembly 2 can adapt to trees with different breast diameters and ground conditions. The operator can quickly adjust the measurement height and position, reducing the time of repeated carrying and setting. It enhances the stability and repeatability of the operation. The connecting assembly 5 ensures that the connecting line of the pair of telescopic rulers 41 is always arranged along the diameter of the circular ring, preventing structural loosening during measurement. At the same time, the sliding design of the measurement assembly 4 allows multiple data collection, further improving data representativeness. The overall structure has functionality and practicality, and can be used stably in complex forest environments, providing reliable technical support for forestry resource investigation and tree growth monitoring.

[0030] Preferably, as shown in Figs. 1-5 The telescopic ruler 41 includes a first ruler body 411 and a second ruler body 412. The first ruler body 411 has a cavity inside. The second ruler body 412 is slidingly inserted into the first ruler body 411. A reset spring 413 is arranged in the cavity. One end of the reset spring 413 is fixedly connected to the first ruler body 411, and the other end is fixedly connected to the second ruler body 412. A scale line 414 is arranged on the second ruler body 412, and the connecting end of the walking wheel 42 is the zero scale end.

[0031] In this embodiment, the reset spring 413 automatically ejects the second ruler body 412 after measurement, reducing the manual operation steps. The zero scale end of the scale line 414 is arranged at the connecting position of the walking wheel 42, so that the reading directly reflects the telescopic displacement, simplifying the breast diameter calculation process and improving the efficiency and accuracy of data processing. This structure ensures measurement accuracy while enhancing device durability and operational continuity, especially suitable for continuous multi-tree measurement scenarios.

[0032] Preferably, as shown in Figs. 1-2 An arc-shaped through slot 6 is formed on the first limiting frame 31 and the second limiting frame 32. A pair of arc-shaped sliding blocks 7 are slidingly arranged in the arc-shaped through slots 7 formed on the first limiting frame 31 and the second limiting frame 32, respectively.

[0033] In this embodiment, the cooperation of the arc-shaped sliding block 7 and the through slot allows the telescopic ruler 41 to be flexibly adjusted in position along the frame, facilitating the measurement requirements in different directions and positions, and improving the adaptability and data diversity of the device; this structure ensures that the measurement assembly 4 remains stable during movement, avoiding shaking or deviation, and further ensuring the reliability and repeatability of the measurement results; the detachable connection design facilitates the maintenance and replacement of components, prolonging the service life of the equipment.

[0034] Preferably, as shown in Figs. 1-2 The connecting assembly 5 includes a connecting frame 51, a connecting cylinder 52, and a threaded column 53. The connecting frame 51 includes a first connecting rod 511 and a pair of second connecting rods 512, which are respectively fixed perpendicularly to the two ends of the first connecting rod 511. A threaded line is opened at the end of the second connecting rod 512 away from the first connecting rod 511. The top end of the connecting cylinder 52 matches the threaded line. The threaded column 53 is rotationally connected with the first ruler body 411. The bottom end of the connecting cylinder 52 is threadedly sleeved on the threaded column 53. The second connecting rod 512 is perpendicular to the first ruler body 411. The length of the first connecting rod 511 is greater than the diameter of the circular ring. The length of the second connecting rod 412 is greater than the radius of the circular ring.

[0035] In this embodiment, the cooperation of the threaded column 53, the connecting cylinder 52, and the connecting frame 51 realizes quick locking and release, improving the operation efficiency and connection stability of the split frame. The length of the first connecting rod 511 is greater than the diameter of the circular ring, ensuring sufficient connection strength in different measurement positions, guaranteeing the structural rigidity during measurement, and the two ends of the first connecting rod 511 are respectively perpendicular to the first connecting rod 511 and the first ruler body 411. The diameter of the first connecting rod 511, the pair of first connecting rods 511, and the circular ring form a rectangle, ensuring that the pair of telescopic rulers 41 are always arranged along the diameter direction of the limiting frame. In this application, the two ends of the connecting cylinder 52 are respectively threadedly connected with the connecting frame 51 and the threaded column 53, and the threaded lines on the connecting frame 51 and the threaded column 53 are in the same direction. When installing, only the connecting cylinder 52 needs to be rotated to complete the installation of the connecting frame 51. In this embodiment, the end of the threaded column 53 away from the connecting cylinder 52 is fixedly connected with a rotating rod, which is rotationally connected with the arc-shaped sliding block 7.

[0036] Preferably, as shown in Fig. 1 The support assembly 1 includes a support seat 101 and a limiting anchor rod 102. The vertical lifting assembly 2 is vertically fixedly connected to the top of the support seat 101. The bottom of the support seat 101 is fixedly connected with the limiting anchor rod 102.

[0037] In this embodiment, the limiting anchor rod 102 can effectively resist lateral force or wind interference after being embedded in the ground, preventing displacement or tilting of the equipment during measurement. It is especially suitable for slopes or soft soil environments, ensuring the reliability of the measurement reference.

[0038] Preferred, such as Figs. 1-5 As shown, the vertical lifting assembly 2 includes a concave frame 21, a lifting block 22, and a threaded rod 23. The concave frame 21 is vertically fixed to the support base 101. The threaded rod 23 passes through the concave frame 21 along its length and is rotatably connected to the concave frame 21. The lifting block 22 is threaded onto the threaded rod 23, and one end is slidably connected to the concave frame 21. The top end of the threaded rod 23 passes through the concave frame 21 and is fixedly connected to a rotating handle 24. The lifting block 22 has an arc-shaped surface on the side near the first limiting frame 31. One end of the first limiting frame 31 is fixedly connected to the lifting block 22, and the other end has a slot 10. One end of the second limiting frame 32 body 3 is connected to the lifting block 22 through a pin 11, and the other end is fixedly connected to an insert 12 that matches the slot 10.

[0039] In this embodiment, the threaded drive provides good self-locking performance and fine-tuning capability, avoiding unexpected changes in height during measurement and ensuring the standardization of the sternum measurement position; the sliding connection structure between the concave frame 21 and the lifting block 22 enhances the stability of the lifting process, prevents uneven loading or jamming, and extends service life. The lifting block 22 can be further configured as a foldable type to facilitate better movement of the device; the plug-in method ensures that the first limiting frame 31 and the second limiting frame 32 are quickly aligned and fixed when closed, avoiding misalignment or gaps and improving the overall integrity of the measurement structure; the arc-shaped surface fits the first limiting frame 31 and the second limiting frame 32 in a symmetrical manner, dispersing stress and reducing wear, improving the durability of the equipment under frequent opening and closing operations.

[0040] Preferred, such as Figs. 1-5 As shown, a marking line 8 is provided on the outer side of the concave frame 21 along the vertical direction, and a through groove is provided through the concave frame 21 along the vertical direction. A marking rod 9 is fixedly connected to the lifting block 22.

[0041] In this embodiment, the marker line 8 and the marker rod 9 work together to quickly determine the position of the lifting block 22, which facilitates repeated positioning and standardized measurement, and reduces human judgment error; the through-slot design not only reduces the structural weight, but also facilitates observation of the internal movement status, and improves the maintainability and operational transparency of the equipment.

[0042] Preferred, such as Figs. 1-4 As shown, a pair of shoulder straps 13 are provided on the side of the concave frame 21 away from the lifting block 22.

[0043] In this embodiment, a pair of shoulder straps 13 provided on the concave frame 21 facilitate the operator to move the entire device.

[0044] The method of using the forestry surveying device of the present invention is as follows: The second limiting frame 32 is manually held and rotated, so that it rotates relative to the vertical lifting assembly 2 around the pin shaft 11, so that the first limiting frame 31 and the second limiting frame 32 are separated from each other to form an open ring structure; the forestry measuring device is moved to the vicinity of the tree to be measured, and the support assembly 1 is operated to stably place it on the ground, so that the device is in a horizontal and stable state; the vertical lifting assembly 2 is manually operated to adjust the height of the lifting end to correspond to the standard breast height measuring height of the tree to be measured; At this time, the tree trunk is located in the center area of the to-be-formed ring, and then the second limiting frame 32 is reversely rotated to gradually approach the first limiting frame 31 and finally combine to form a complete ring structure surrounding the trunk; it is ensured that the diameter of the combined ring is greater than the diameter of the tree to be measured, so that the trunk does not contact the inner wall of the ring; After the first limiting frame 31 and the second limiting frame 32 are combined, a pair of telescopic rulers 41 are fastened and connected through the connecting assembly 5, and the pair of telescopic rulers 41 are arranged along the diameter of the ring, and it is ensured that the first limiting frame 31 and the second limiting frame 32 remain in a stable combined state during the measurement; The telescopic rulers 41 are pulled and the walking wheels 42 are brought into contact with the surface of the tree to be measured, and after the device is kept stable and all the walking wheels 42 are in stable contact with the trunk, data reading is performed; since the telescopic rulers 41 can be telescoped with the change of the circumference of the trunk, the scale value displayed on each telescopic ruler 41 is read to obtain the extension length of each measuring point relative to the initial zero position, and since the diameter of the ring, the initial length of the telescopic ruler 41 and the diameter of the walking wheel 42 are fixed values, the diameter of the ring is subtracted from the length of the measuring ruler located on the first limiting frame 31 and the second limiting frame 32 and the length of the walking wheel 42 to obtain the breast height of the tree to be measured; By pulling the connecting assembly 5 to make the first limiting frame 31 body 3 and the second limiting frame 32 body slide, a plurality of breast heights of the trees to be measured can be obtained by the above-mentioned method, so as to improve the accuracy of the measurement.

[0045] Although the embodiments of the present application have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A forestry surveying device, characterized in that, It includes a support component and a vertical lifting component disposed on the support component, and further includes; The limiting frame includes a first limiting frame and a second limiting frame. The first limiting frame is fixedly installed on the lifting end of the vertical lifting component, and the second limiting frame is rotatably connected to the vertical lifting component through a pin. When the first limiting frame and the second limiting frame are assembled, they form a complete ring. The measuring component includes a telescopic ruler and wheels. A pair of telescopic rulers are provided, which are slidably mounted on the first limiting frame and the second limiting frame respectively via arc-shaped sliding blocks. The wheels are installed on the telescopic ends of the pair of telescopic rulers. The connecting component is detachably connected to the outside of the pair of arc-shaped sliding blocks, and when connected, the pair of telescopic rulers are located on the same straight line and are arranged along the diameter of the ring.

2. The forestry surveying device as described in claim 1, characterized in that, The telescopic ruler includes a first ruler body and a second ruler body. The first ruler body has a cavity inside, and the second ruler body is slidably inserted into the first ruler body. A return spring is provided in the cavity. One end of the return spring is fixedly connected to the first ruler body, and the other end is fixedly connected to the second ruler body. The second ruler body has scale lines, and the end connected to the traveling wheel is the zero scale end.

3. A forestry surveying device as described in claim 2, characterized in that, Both the first limiting frame and the second limiting frame are provided with arc-shaped through slots, and a pair of arc-shaped sliding blocks are respectively slidably disposed in the arc-shaped through slots provided in the first limiting frame and the second limiting frame.

4. A forestry surveying device as described in claim 3, characterized in that, The connecting assembly includes a connecting frame, a connecting cylinder, and a threaded post. The connecting frame includes a first connecting rod and a pair of second connecting rods. The pair of second connecting rods are respectively vertically fixed to both ends of the first connecting rod. The end of the second connecting rod away from the first connecting rod has a threaded line. The top end of the connecting cylinder matches the threaded line. The threaded post is rotatably connected to the first ruler body. The bottom end of the connecting cylinder is threaded onto the threaded post. The second connecting rod is perpendicular to the first ruler body. The length of the first connecting rod is greater than the diameter of the ring, and the length of the second connecting rod is greater than the radius of the ring.

5. A forestry surveying device as described in claim 1, characterized in that, The support assembly includes a support base and a limiting anchor rod. The vertical lifting assembly is vertically fixedly connected to the top of the support base, and the limiting anchor rod is fixedly connected to the bottom of the support base.

6. A forestry surveying device as described in claim 5, characterized in that, The vertical lifting assembly includes a concave frame, a lifting block, and a threaded rod. The concave frame is vertically fixed to the support base. The threaded rod passes through the concave frame along its length and is rotatably connected to it. The lifting block is threaded onto the threaded rod, with one end slidably connected to the concave frame. A rotating handle is fixedly connected to the top of the threaded rod, passing through the concave frame. The lifting block has an arc-shaped surface near the first limiting frame. One end of the first limiting frame is fixedly connected to the lifting block, and the other end has a slot. One end of the second limiting frame is connected to the lifting block via a pin, and the other end is fixedly connected to a plug that matches the slot.

7. A forestry surveying device as described in claim 6, characterized in that, The concave frame has a vertical marking line on its outer side, and a through slot is opened through the concave frame in the vertical direction. A marking rod is fixedly connected to the lifting block.

8. A forestry surveying device as described in claim 6, characterized in that, The concave frame is provided with a pair of shoulder straps on the side away from the lifting block.

9. The method of using the forestry surveying device as described in any one of claims 1-8, characterized in that, Includes the following steps: Manually grasp and rotate the second limiting frame to form an open ring structure with the first limiting frame and the second limiting frame; then place the support component stably on the ground, and manually operate the vertical lifting component to adjust the height of its lifting end to correspond to the standard diameter at breast height measurement height of the tree to be measured; At this point, the tree trunk is located in the center of the ring that is about to be formed. Then, the second limiting frame is rotated in the opposite direction so that it gradually approaches and finally joins with the first limiting frame to form a complete ring structure that surrounds the tree trunk. The pair of telescopic rulers are fastened together by the connecting components and the pair of telescopic rulers are arranged along the diameter of the ring, ensuring that the first limiting frame and the second limiting frame maintain a stable joining state during the measurement process. Press the telescopic ruler and bring the traveling wheels into contact with the surface of the tree to be measured. Keep the device stable until all traveling wheels are in stable contact with the trunk, and then read the data. By reading the scale value displayed on each telescopic ruler, the extension length of each measurement point relative to the initial zero position is obtained. The diameter at breast height (DBH) of the tree to be measured is obtained by subtracting the length of the measuring ruler and the traveling wheels located on the first and second limit frames from the diameter of the ring. Pull the connecting assembly to make a pair of traveling wheels roll on the surface of the tree to be measured, and measure different positions of the tree to be measured in the same plane to ensure measurement accuracy.

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