High-precision tree DBH (diameter at breast height) measuring device and measuring method based on laser measurement

Abstract

The invention relates to the technical field of tree diameter at breast height measurement, and discloses a high-precision tree diameter at breast height measurement device based on laser measurement and a measurement method.The high-precision tree diameter at breast height measurement device comprises an annular folding guide rail, a sliding guide rail, a sliding block and a laser distance sensor, and the annular folding guide rail is formed by connecting a fixed arc-shaped support and a folding arc-shaped support through a reverse hinge; a stable annular support can be formed after being unfolded, and the rigidity is enhanced in cooperation with an arc-shaped pin interlocking mechanism; the laser distance sensor comprises multiple sets of distance sensors facing different directions, dead-corner-free data acquisition of the peripheral contour of a tree is achieved, data are transmitted to the metering terminal through a wireless network, the flat plate support is fixed to the guide rail through threaded connection, and a bottom bending groove and a top elastic clamping mechanism of the flat plate support ensure stable installation of the metering terminal. The lower fixing rod is matched with the positioning blocking piece, the guide rail is automatically calibrated to the 1.3-meter standard diameter at breast height, the device has the advantages of portability, stability and automation, and the accuracy and efficiency of diameter at breast height measurement in the complex environment are effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tree diameter measurement, and particularly relates to a high-precision tree diameter measurement device and method based on laser measurement. BACKGROUND

[0002] In the field of forestry resource investigation and monitoring, the tree diameter is a core parameter for evaluating the growth state, volume and ecological benefits of the forest.

[0003] At present, the traditional diameter measurement method mainly relies on manual measurement using a tape or a girth stick, and has problems of complicated operation, large human reading error and low efficiency, especially when the complex terrain or multiple trees are adjacent, the data deviation is caused by the irregular shape of the tree trunk and the deviation of the measurement position from the standard height. With the development of automatic measurement technology, non-contact measurement devices based on laser ranging are gradually applied in the forestry field. SUMMARY The technical problem to be solved by the present application is that the traditional tree diameter measurement method has the disadvantages of complicated operation, large human reading error and low efficiency in the prior art. Therefore, the present application provides a high-precision tree diameter measurement device and method based on laser measurement.

[0004] In order to achieve the above purpose, the following technical scheme is adopted in the present application: a high-precision tree diameter measurement device based on laser measurement, comprising: a ring-shaped folding guide rail composed of one fixed arc-shaped support and two or more folding arc-shaped supports, a sliding guide rail is fixedly connected to the inner side of the fixed arc-shaped support and the folding arc-shaped support, a sliding block is slidably connected to the sliding guide rail, a laser distance sensor is fixedly connected to the sliding block, the laser measurement instrument contains three or more laser distance sensors, and all the laser distance sensors are respectively directed in different directions, so that the laser tracks are uniformly distributed in the fan-shaped range, the outer periphery of the tree is covered by the multi-directional laser beams, the profile data acquisition is ensured without dead angle, and the measurement comprehensiveness is effectively improved, the laser distance sensor is connected to a metering terminal through a wireless network, real-time transmission and processing of the measurement data can be realized, and manual recording error is avoided.

[0005] Preferably, the fixed arc-shaped support and the folding arc-shaped support are connected through hinges, the folding arc-shaped supports are also connected through hinges, and the installation directions of the two adjacent hinges are opposite, the reverse hinge structure not only ensures that the guide rail can be folded and stored for convenient carrying and transportation, but also forms a stable ring-shaped support when unfolded to prevent radial deformation from affecting the measurement accuracy.

[0006] Preferably, a center groove is arranged in the fixed arc-shaped support and the folding arc-shaped support, an arc-shaped pin is inserted into the center groove, the arc-shaped pin is equal in length to the fixed arc-shaped support and the folding arc-shaped support, a sliding limiting groove is further arranged above the center groove of the fixed arc-shaped support, the length of the sliding limiting groove is half of the fixed arc-shaped support, a pushing block is further fixedly connected to the arc-shaped pin in the fixed arc-shaped support, the pushing block slides in the sliding limiting groove, the arc-shaped pin is interlocked and inserted into the center groove of the adjacent support 5 through the pushing block, a rigid ring-shaped structure is formed, external collision or tree swaying interference in the measurement process is effectively resisted, and the guide rail structure is stable and reliable.

[0007] Preferably, a flat support is fixedly connected to one side of the fixed arc-shaped support through threads, the metering terminal is placed on the flat support, the flat support provides a stable installation platform for the metering terminal, the threaded connection mode facilitates disassembly and maintenance, and the device usability is improved.

[0008] Preferably, the bottom of the flat support is bent into a groove, and a flat fixing mechanism is arranged at the top two corners of the flat support, the bottom bent groove is matched with the bottom of the metering terminal, and double limiting can be formed by cooperating with the top fixing mechanism to prevent displacement of the terminal due to vibration in the measurement process.

[0009] Preferably, the flat fixing mechanism comprises a movable pin, the movable pin penetrates through the flat support, one end of the movable pin is fixedly connected with a rotating clamping block, the other end of the movable pin is fixedly connected with a spring stopper, a pressure spring is arranged outside the movable pin, the pressure spring is located between the spring stopper and the flat support, the pressure spring can provide self-adaptive clamping force, different thicknesses of the metering terminal can be adapted, the rotating clamping block realizes quick tightening and loosening operation, and the terminal installation is firm and the communication is stable.

[0010] Preferably, two fixed rods are fixedly connected below the flat support through threads, a positioning stopper is fixedly connected to the lower part of the fixed rod, the distance between the positioning stopper and the annular folding guide rail is 1.3 meters, the fixed rod is matched with the positioning stopper, the height of the guide rail can be quickly positioned, the measurement position strictly meets the requirement of 1.3-meter height of the diameter at breast height in the forestry measurement standard, and the manual adjustment error is avoided.

[0011] Preferably, the distance between the positioning stopper and the annular folding guide rail is 1.3 meters, the parameter repeatedly limits the key measurement reference, and the comparability of the measurement data in different environments can be ensured.

[0012] The present application provides another technical solution: a measurement method of a high-precision tree diameter measurement device based on laser measurement, characterized by comprising the following steps: S1. Measurement preparation: Install and debug the hardware equipment, ensure that the ring track, slider and laser measuring instrument are working properly, adjust the track height to 1.3 meters above the ground, and realize automatic calibration by positioning the ground limiting piece, ensure that the measurement position meets the standard breast height measurement height and reduces the manual operation steps; S2. Data acquisition: Let the slider slide around the sliding guide rail for one round, the laser distance sensor emits laser beams at the same time, the encoder monitors the slider position in real time, when the slider reaches the preset acquisition position, the encoder sends a trigger signal to control multiple laser distance sensors to emit laser beams at the same time, the sensor receives the reflected signal, calculates the distance data to the tree, and associates with the position information provided by the encoder, and stores it as the original profile data. The high-precision position monitoring of the encoder combined with the synchronous triggering of multiple sensors can ensure that the distance data at each angle position is accurately corresponding, forming a complete set of tree circumference profile coordinate points; S3. Data processing and calculation: The original profile data is preprocessed, and the median filter and Gaussian filter method is used to remove noise. The double filtering algorithm can effectively filter out environmental light interference, leaf shaking and other random noise, and improve the data purity. The edge detection algorithm is used to find the profile boundary points, and then the clustering algorithm is used to distinguish the profiles of different trees. The edge detection can accurately locate the boundary of the tree bark, and the clustering algorithm can solve the profile separation problem of multiple trees adjacent to each other, and realize the independent identification of single tree. For each clustered profile point, the least square method is used for circle fitting to determine the center coordinates and radius, and then the tree breast height is calculated. The least square fitting can improve the calculation accuracy of the circle parameters, effectively reduce the measurement error, and meet the high-precision measurement requirements of forestry.

[0013] Preferably, S1. Measurement preparation includes the following steps: S1001. Guide rail unfolding and fixing: unfold the folded arc-shaped support through the hinge to form a complete folded ring guide rail, insert the fixed rod into the ground to the position of the ground limiting piece, and ensure that the center height of the guide rail is 1.3 meters. Interlocking fixing mechanism: push the push block of the fixed arc-shaped support, and insert the arc-shaped pin into the center groove of the adjacent support through interlocking, forming a rigid ring structure. This unfolding process does not require additional tools, and can quickly build a measurement reference platform. The interlocking mechanism can eliminate the connection gap between the supports, ensuring the overall rigidity of the guide rail; S1002. Installation of measurement terminal: Place the measurement terminal in the groove at the bottom of the flat bracket, rotate the movable pin to press the rotating clamp block against the terminal, and the pressure spring provides adaptive clamping force to ensure stable wireless communication. The combination of groove positioning and elastic clamping can prevent the terminal from falling off due to vibration in complex outdoor environments, ensuring the continuity of data transmission; S1003. System initialization: start the laser distance sensor, calibrate the angle parameters of the three sets of above sensors, factory default fan-shaped uniform distribution, respectively +30°, -30°, 0°; initialize the encoder, set and data acquisition interval, so that the angle resolution is less than or equal to 1°, and the angle parameter calibration can ensure that the laser beam uniformly covers the measurement area according to the preset angle, and the angle resolution better than 1° can ensure high-density collection of profile data, providing a data basis for subsequent high-precision fitting.

[0014] Technical effects and advantages of the present application: In the present application, through the hinge type foldable structure of the annular folding guide rail and the arc-shaped pin interlocking fixing mechanism, the portable storage and rigid support of the device are realized, which can be quickly calibrated to 1.3 meter standard chest diameter measurement height through the positioning baffle, and can resist external interference to ensure the stability of the guide rail; the laser distance sensor uniformly distributed in multiple directions cooperates with the encoder to trigger and collect synchronously, realizes high-density data collection of the tree trunk circumference profile without dead angle, and combines the multi-layer data processing technology of median filter, Gaussian filter, edge detection, clustering algorithm and least square circle fitting to effectively filter out noise, separate multiple tree profiles and accurately fit the trunk cross section circle, which significantly improves the chest diameter measurement precision in complex environment; the flat bracket and elastic clamping mechanism guarantee the stable installation and communication of the measurement terminal, and the fixed rod plug-in installation design realizes the rapid deployment of a single person, the whole process of automatic measurement avoids the manual operation error, and the whole has the measurement accuracy, environmental adaptability and operation convenience, which meets the high-precision chest diameter measurement demand of forestry. BRIEF DESCRIPTION OF DRAWINGS

[0015] The disclosed content of the present application is explained with reference to the accompanying drawings. It should be understood that the drawings are only for illustrative purposes, and are not intended to limit the scope of protection of the present application. In the drawings, the same reference signs are used to refer to the same parts: Figure 1 It is an appearance structure diagram of the present application; Figure 2 It is an annular folding guide rail structure diagram of the present application; Figure 3 It is an annular folding guide rail structure diagram of the present application after folding Figure 1 ; Figure 4 It is an annular folding guide rail structure diagram of the present application after folding Figure 2 ; Figure 5 It is a fixed arc-shaped bracket and flat bracket connection structure diagram of the present application; Figure 6 It is a flat fixing mechanism structure diagram of the present application; Figure 7 It is a cross-sectional structure diagram of the annular folding guide rail of the present application; Figure 8It is a fixed arc support structure schematic diagram of the application; Figure 9 It is a fixed arc support and folding arc support structure schematic diagram of the application; Figure 10 It is a slider and laser measuring instrument structure schematic diagram of the application.

[0016] Legend: 1, annular folding guide rail; 101, fixed arc support; 102, folding arc support; 2, sliding guide rail; 3, slider; 4, laser measuring instrument; 5, center groove; 6, arc-shaped pin; 7, sliding limiting groove; 8, push block; 9, flat support; 10, meter terminal; 11, flat fixing mechanism; 1101, movable pin; 1102, rotating clamping block; 1103, spring stopper; 1104, pressure spring; 12, fixed rod; 13, positioning stopper. DETAILED DESCRIPTION

[0017] It is easy to understand that according to the technical scheme of the application, those skilled in the art can propose a variety of structure modes and implementation modes which can be replaced with each other without changing the essential spirit of the application. Therefore, the following specific embodiments and drawings are only exemplary descriptions of the technical scheme of the application, and should not be regarded as the whole or regarded as the limitation or restriction of the technical scheme of the application.

[0018] Reference Figures 1-10 As shown in the figure, the application provides a technical scheme: a high-precision tree diameter measuring device based on laser measurement, comprising: Guide rail main body structure: The annular folding guide rail 1 is composed of one fixed arc-shaped support 101 and two or more folding arc-shaped supports 102. The fixed arc-shaped support 101 and the folding arc-shaped supports 102 are connected by hinges. The folding arc-shaped supports 102 are also connected by hinges, and the installation directions of the two adjacent hinges are opposite. The reverse hinge structure can ensure that the guide rail can be folded and stored for convenient carrying and transportation, and can form a stable annular support when unfolded to prevent radial deformation from affecting the measurement accuracy. The fixed arc-shaped support 101 and the folding arc-shaped supports 102 are provided with a center groove 5. An arc-shaped pin 6 is inserted into the center groove 5. The arc-shaped pin 6 is the same length as the fixed arc-shaped support 101 and the folding arc-shaped supports 102. A sliding limiting groove 7 is also provided above the center groove 5 of the fixed arc-shaped support 101. The length of the sliding limiting groove 7 is half of the fixed arc-shaped support 101. A push block 8 is also fixedly connected to the arc-shaped pin 6 in the fixed arc-shaped support 101. The push block 8 slides in the sliding limiting groove 7. The arc-shaped pin 6 is driven by the push block 8 to be inserted into the center groove 5 of the adjacent support. A rigid annular structure can be formed to effectively resist interference caused by external impact or tree sway during measurement, ensuring the stability and reliability of the guide rail structure. A flat support 9 is fixedly connected to one side of the fixed arc-shaped support 101 by screwing. A measurement terminal 10 is placed on the flat support 9. The flat support 9 provides a stable mounting platform for the measurement terminal 10. The screw connection method facilitates disassembly and maintenance, and can improve the ease of use of the device.

[0019] Measurement assembly: The fixed arc-shaped support 101 and the folding arc-shaped supports 102 are fixedly connected with a sliding guide rail 2. A sliding block 3 is slidingly connected to the sliding guide rail 2. A laser distance sensor is fixedly connected to the sliding block 3. The laser distance sensor is connected to the measurement terminal 10 through a wireless network, and the measurement data can be transmitted and processed in real time, avoiding manual recording errors.

[0020] Auxiliary support and positioning system: The bottom of the flat support 9 is bent into a groove, and the top of the flat support 9 is provided with a flat fixing mechanism 11 at two corners, the bottom bending groove is matched with the bottom of the metering terminal 10, and double limiting can be formed by cooperating with the top fixing mechanism to prevent displacement of the terminal during measurement due to vibration. The flat fixing mechanism 11 comprises a movable pin 1101, the movable pin 1101 penetrates the flat support 9, one end of the movable pin 1101 is fixedly connected with a rotating clamping block 1102, the other end of the movable pin 1101 is fixedly connected with a spring stop piece 1103, the movable pin 1101 is provided with a pressure spring 1104, the pressure spring 1104 is located between the spring stop piece 1103 and the flat support 9, the pressure spring 1104 can provide self-adapting clamping force, can adapt to metering terminals 10 of different thicknesses, the rotating clamping block 1102 realizes quick tightening operation, ensures firm installation of the terminal and stable communication. Two fixed rods 12 are fixedly connected below the flat support 9 through threads, the fixed rods 12 are fixedly connected with positioning stop pieces 13 at the lower parts, the distance between the positioning stop pieces 13 and the annular folding guide rail 1 is 1.3 meters, the fixed rods 12 are matched with the positioning stop pieces 13, can realize quick positioning of the guide rail height, ensures that the measurement position strictly meets the requirement of 1.3-meter height of the diameter at breast height in the forestry measurement standard, avoids manual adjustment error. The distance between the positioning stop pieces 13 and the annular folding guide rail 1 is 1.3 meters, the parameter repeatedly limits the key measurement datum, can ensure comparability of measurement data in different environments.

[0021] A measurement method of a high-precision tree diameter measurement device based on laser measurement, comprising the following steps: S1. Measurement preparation: Install and debug the hardware equipment, ensure that the ring track 1, slider 3, laser measuring instrument 4 work normally. First, the guide rail is unfolded and fixed: the folding arc-shaped support 102 is unfolded through the hinge, forming a complete ring-shaped folding guide rail, the fixed rod 12 is inserted into the ground to the ground-touching positioning baffle 13, ensuring that the center height of the guide rail is 1.3 meters, this process is automatically calibrated by the ground-touching positioning baffle 13, ensuring that the measurement position meets the standard chest diameter measurement height and reducing manual operation steps; then push the push block 8 of the fixed arc-shaped support 101, and insert the arc-shaped pin 6 into the center groove 5 of the adjacent support through interlocking, forming a rigid ring-shaped structure, this unfolding process does not require additional tools, and can quickly build a measurement reference platform, the interlocking mechanism can eliminate the connection gap between the supports, ensuring the overall rigidity of the guide rail. Then install the metering terminal 10: place the metering terminal 10 at the bottom groove of the flat bracket 9, rotate the movable pin 1101 to make the rotating clamp block 1102 press the terminal, and the pressure spring 1104 provides adaptive clamping force to ensure stable wireless communication. The combination of groove positioning and elastic clamping can prevent the terminal from falling off due to vibration in complex outdoor environments, ensuring data transmission continuity. Finally, system initialization: start the laser distance sensor, calibrate the angle parameters of the three groups of sensors, and the factory default fan-shaped uniform distribution is +30°, -30°, 0°, ensuring that the laser beam uniformly covers the measurement area at the preset angle; initialize the encoder, set the data acquisition interval, so that the angle resolution is ≤1°, and an angle resolution better than 1° can ensure high-density collection of profile data, providing a data basis for subsequent high-precision fitting.

[0022] S2. Data acquisition: let the slider 3 rotate around the sliding guide rail 2, the laser distance sensor simultaneously emits a laser beam, and the encoder monitors the position of the slider 3 in real time. When the slider 3 reaches the preset collection position, the encoder sends a trigger signal to control multiple groups of laser distance sensors to emit laser beams simultaneously. The sensor receives the reflected signal, calculates the distance data to the tree, and associates it with the position information provided by the encoder to store it as raw profile data. The combination of high-precision position monitoring of the encoder and synchronous triggering of multiple sensors can ensure that the distance data at each angle position is accurately corresponding, forming a complete set of tree circumference profile coordinate points.

[0023] S3. Data processing and calculation: The original contour data is pre-processed, and the noise is removed by using median filtering and Gaussian filtering method, the double filtering algorithm can effectively filter out random noise such as environmental light interference and leaf shaking, and improve the data purity; the edge detection algorithm is used to find the contour boundary point, and then the clustering algorithm is used to distinguish the contours of different trees, the edge detection can accurately locate the boundary of the tree bark, and the clustering algorithm can solve the contour separation problem of multiple trees, and realize the independent identification of single tree; for each clustered contour point, the least square method is used for circle fitting to determine the center coordinates and radius, and then the diameter at breast height of the tree is calculated, the least square fitting can improve the calculation accuracy of the circle parameters, effectively reduce the measurement error, and meet the high-precision measurement requirement of forestry.

[0024] Working principle: When measuring, first insert the lower end of the fixed rod 12 into the ground until the positioning flapper 13 is flush with the ground, at this time the height of the annular folding guide rail 1 is 1.3 meters, which is consistent with the height of the tree diameter measurement.

[0025] Then unfold the annular folding guide rail 1, that is, unfold the folded arc-shaped support 102 through the hinge to form a ring, enclose the tree to be measured inside the ring, then push the arc-shaped pin 6 in the fixed arc-shaped support 101 to move and insert it into the center groove 5 on the adjacent folded arc-shaped support 102, thereby pushing the arc-shaped pin 6 in the adjacent folded arc-shaped support 102, thereby forming a chain reaction, sequentially pushing the arc-shaped pin 6 in each folded arc-shaped support 102 to insert into the center groove 5 on the adjacent folded arc-shaped support 102, until the arc-shaped pin 6 in the last folded arc-shaped support 102 is inserted into the center groove 5 of the fixed arc-shaped support 101, thereby realizing the fixation of the annular folding guide rail 1 and ensuring the stability of the annular folding guide rail 1.

[0026] Subsequently, place the measurement terminal 10 in the groove at the bottom of the flat support 9, and rotate the flat fixing mechanism 11 at the two corners at the top of the flat support 9 to press the two corners of the measurement terminal 10 with the rotating clamping block 1102, and then ensure the stable data connection between the measurement terminal 10 and the laser measuring instrument 4.

[0027] After preparation, rotate the slider 3 and the laser measuring instrument 4 around the sliding guide rail 2 for one turn to collect data of the trees inside, measure the distance from the tree bark to the laser measuring instrument 4 by using the laser distance sensor, thereby collecting the contour coordinate information of the trees, then identify the number and position of the trees in the range based on the contour recognition algorithm, and calculate the diameter at breast height of each tree in the range through the diameter at breast height calculation algorithm.

[0028] The technical scope of the present application is not limited to the content in the above description, and those skilled in the art can make various modifications and changes to the above embodiments without departing from the technical idea of the present application, and these modifications and changes shall be within the protection scope of the present application.

Claims

1. A high-precision tree diameter at breast height (DBH) measurement device based on laser measurement, characterized in that, include: The annular folding guide rail consists of a fixed arc-shaped support section and two or more folding arc-shaped supports. A sliding guide rail is fixedly connected to the inner side of the fixed arc-shaped support and the folding arc-shaped support. A slider is slidably connected to the sliding guide rail, and a laser measuring instrument is fixedly connected to the slider. The laser measuring instrument contains three or more sets of laser distance sensors, and all the laser distance sensors are oriented in different directions, so that the laser trajectory is evenly distributed within a fan-shaped range. The laser measuring instrument is connected to a metering terminal via a wireless network.

2. The high-precision tree diameter at breast height (DBH) measuring device based on laser measurement according to claim 1, characterized in that, The fixed arc-shaped bracket and the folding arc-shaped bracket are connected by hinges, and the folding arc-shaped brackets are also connected by hinges, with adjacent sets of hinges installed in opposite directions.

3. The high-precision tree diameter at breast height (DBH) measuring device based on laser measurement according to claim 1, characterized in that, Both the fixed arc-shaped bracket and the folding arc-shaped bracket have a central groove, into which an arc-shaped pin is inserted. The arc-shaped pin is the same length as the fixed arc-shaped bracket and the folding arc-shaped bracket. A sliding limiting groove is also provided above the central groove on the fixed arc-shaped bracket. The length of the sliding limiting groove is half that of the fixed arc-shaped bracket. A pushing block is also fixedly connected to the arc-shaped pin in the fixed arc-shaped bracket. The pushing block slides in the sliding limiting groove.

4. The high-precision tree diameter at breast height (DBH) measuring device based on laser measurement according to claim 1, characterized in that, A flat plate bracket is fixedly connected to one side of the fixed arc-shaped bracket by threads, and the metering terminal is placed on the flat plate bracket.

5. The high-precision tree diameter at breast height (DBH) measuring device based on laser measurement according to claim 4 is characterized in that, The bottom of the flat plate bracket is bent into a groove, and a flat plate fixing mechanism is provided at the two top corners of the flat plate bracket.

6. A high-precision tree diameter at breast height (DBH) measuring device based on laser measurement according to claim 5, characterized in that, The plate fixing mechanism includes a movable pin that passes through the plate support. One end of the movable pin is fixedly connected to a rotating block, and the other end of the movable pin is fixedly connected to a spring stop plate. A pressure spring is sleeved on the movable pin and is located between the spring stop plate and the plate support.

7. A high-precision tree diameter at breast height (DBH) measuring device based on laser measurement according to claim 5, characterized in that, Two fixing rods are threadedly connected to the bottom of the flat plate support. A positioning baffle is fixedly connected to the lower part of the fixing rod. The distance between the positioning baffle and the annular folding guide rail is 1.3 meters.

8. A high-precision tree diameter at breast height (DBH) measuring device based on laser measurement according to claim 7, characterized in that, The distance between the positioning baffle and the annular folding guide rail is 1.3 meters.

9. A measurement method for a high-precision tree diameter at breast height (DBH) measurement device based on laser measurement according to any one of claims 1-8, characterized in that, Includes the following steps: S1. Measurement Preparation: Install and debug the hardware equipment to ensure that the circular track, slider, and laser measuring instrument are working properly. Adjust the track height to 1.3 meters above the ground to ensure that the measurement position meets the standard breast diameter measurement height. S2. Data Acquisition: The slider is made to rotate around the sliding guide rail once. The laser distance sensor emits a laser beam at the same time. The encoder monitors the position of the slider in real time. When the slider reaches the preset acquisition position, the encoder sends a trigger signal to control multiple sets of laser distance sensors to emit laser beams at the same time. The sensor receives the reflected signal, calculates the distance data to the tree, and associates it with the position information provided by the encoder, and stores it as the original contour data. S3. Data Processing and Calculation: The original contour data is preprocessed by removing noise using median filtering and Gaussian filtering. An edge detection algorithm is used to find contour boundary points, and then a clustering algorithm is used to distinguish the contours of different trees. For each clustered contour point, the least squares method is used to fit a circle to determine the center coordinates and radius, and then the diameter at breast height of the tree is calculated.

10. The measurement method of a high-precision tree diameter at breast height (DBH) measurement device based on laser measurement according to claim 9, characterized in that, The S1. Measurement preparation includes the following steps: S1001. Guide rail unfolding and fixing: unfold the folding arc bracket through the hinge to form a complete ring folding guide rail. Insert the fixing rod into the ground until the positioning baffle touches the ground to ensure that the center height of the guide rail is 1.3 meters. Interlocking fixing mechanism: push the pushing block of the fixed arc bracket, and insert it into the center groove of the adjacent bracket through the arc pin interlocking to form a rigid ring structure. S1002. Installation of the metering terminal: Place the metering terminal in the groove at the bottom of the flat plate bracket, rotate the movable pin to make the rotating block press the terminal, and the pressure spring provides adaptive clamping force to ensure stable wireless communication; S1003. System Initialization: Start the laser measuring instrument, calibrate the angle parameters of three or more sets of sensors, and set the factory preset even distribution of the sector as +30°, -30°, and 0° respectively; initialize the encoder, set the data acquisition interval, and make the angle resolution ≤1°.

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