A method and system for measuring the height of a distant standing tree based on angle correction

Abstract

The application discloses a kind of based on angle correction's remote standing tree height measurement method and system, it is related to standing tree data measurement technical field, mainly includes steps: with vertical state as initial state starts to control each sighting rod to target standing tree direction vertical rotation;Respectively obtain the first space coordinates, second angle inductive quantity and second space coordinates and target space coordinates when target standing tree bottom end, top end image;Through the mark device placed at target standing tree obtains target space coordinates;Based on the principle of triangle correlation, target standing tree height is calculated.The application is based on the principle of triangle correlation, solve the measurement error caused by observation angle of view change under complex terrain, so as to more accurately realize standing tree data acquisition, reduce the operation difficulty while improving measurement efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of standing tree data measurement, and particularly relates to a far-end standing tree height measurement method and system based on angle correction. BACKGROUND

[0002] Diameter at breast height and tree height are main indexes of standing tree growth measurement and important properties of forest resource investigation. They are not only main indexes for calculating forest stock volume, but also can reflect forest structure and quality in depth.

[0003] Diameter at breast height is one of the most basic factors in forest resource investigation. Traditional diameter at breast height measurement methods adopt tools such as hook ruler, caliper, and perambulator. Caliper has limited measurement range and is not suitable for measuring large-diameter trees. The measurer's hands need to contact the tree trunk when using the perambulator, and the operation is relatively complex. For diameter at breast height measurement of a large number of standard trees, usually two persons are needed to cooperate to complete the measurement and record, and to perform statistical calculation in the office. The process is time-consuming and error-prone. The function is single and imprecise. The data is read and recorded manually, which is low in efficiency and easy to make mistakes. The data is difficult to be timely stored in the database and positioned, which has been affecting the quality of forest resource investigation. In recent years, some new products have emerged to try to solve this problem by using electronic technology, such as total station measurement, laser scanner, and electronic tape ruler. However, the above products have many problems such as complex device operation, inconvenient field carrying, difficulty in measuring in dense forest, poor anti-interference performance, high equipment cost, and low measurement efficiency, and have not been widely applied.

[0004] Tree height is an important part of tree growth measurement and one of the important indexes for reasonably evaluating the quality of standing trees and the growth condition of trees in the sample plot. Accurate, fast, and efficient standing tree height measurement is crucial for estimating forest stock volume and growth. With the development of sensing technology and the proposal of "digital forestry", the measurement accuracy of the traditional visual method has far failed to meet the requirements of forest resource investigation. Using sensing technology to measure tree height has become an important trend. In recent years, more and more professional tree height measuring instruments have appeared on the market, such as Brulé measuring height device, theodolite, total station, and airborne laser radar, to solve the problem of inaccurate tree height measurement. However, these instruments are not convenient to carry, expensive, and complex to operate, and have not been widely applied. SUMMARY

[0005] In order to accurately, efficiently, and simply collect data such as tree height and diameter at breast height of standing trees in complex mountainous environments, and avoid the influence of height difference on measurement data, the present application provides a far-end standing tree height measurement method based on angle correction. The method comprises a measuring rod, the first end of which is rotatably connected with the first sighting rod and the second sighting rod at the end thereof, and an angle sensor is arranged at the rotatable connection position. The method comprises the following steps:

[0006] S1: fix the measuring rod at the distal end, and start to control the vertical rotation of each sighting rod towards the target standing tree direction in the vertical state as the initial state until the first sighting rod obtains the image of the bottom end of the target standing tree;

[0007] S2: keep the position state of the first sighting rod and record the first angle sensing quantity of the angle sensor at this time and the first space coordinates of the end of the first sighting rod;

[0008] S3: control the second sighting rod to continue vertical rotation until the second sighting rod obtains the image of the top end of the target standing tree;

[0009] S4: keep the position state of the second sighting rod and record the second angle sensing quantity of the angle sensor at this time and the second space coordinates of the end of the second sighting rod;

[0010] S5: obtain the target space coordinates through the marking device placed at the target standing tree;

[0011] S6: according to the first angle sensing quantity and the first space coordinates, the second angle sensing quantity and the second space coordinates and the target space coordinates, the target standing tree height is calculated based on the related principle of triangle.

[0012] Further, the first line formed by the first space coordinates and the second space coordinates is in parallel with the second line formed by the first end and the second end of the target standing tree in space.

[0013] Further, the angle obtained by subtracting the first angle sensing quantity from the second angle sensing quantity is the included angle between the first end and the second end of the target standing tree.

[0014] Further, in the S6 step, the target standing tree height calculation is expressed as the following formula:

[0015]

[0016] In the formula, H is the target standing tree height, L1 is the length of the sighting rod, ∠1 is the first angle sensing quantity, ∠2 is the second angle sensing quantity, x1 is the horizontal coordinate of the second space coordinates, and x2 is the horizontal coordinate of the first space coordinates.

[0017] Further, the ends of the first sighting rod and the second sighting rod and the marking device are all provided with UWB modules for sending space coordinate information.

[0018] The application further provides a distal standing tree height measuring system based on angle correction, which comprises:

[0019] a measuring rod, the end of which is rotationally connected with the first end of the first sighting rod and the second sighting rod, and is provided with an angle sensor at the rotation connection.

[0020] A marking device is placed at the target tree for sending the target spatial coordinates;

[0021] When the tree height of the target tree is measured, the measuring rod is fixed to the distal end, wherein,

[0022] The first sighting rod and the second sighting rod start to rotate vertically in the direction of the target tree in the initial state of the vertical state, the position state of the first sighting rod is kept when the first sighting rod obtains the image of the bottom end of the target tree, and the first angle sensing amount of the angle sensor at this time and the first spatial coordinates of the end of the first sighting rod are recorded, the position state of the second sighting rod is kept when the second sighting rod obtains the image of the top end of the target tree, and the second angle sensing amount of the angle sensor at this time and the second spatial coordinates of the end of the second sighting rod are recorded.

[0023] Further comprising a calculation module for calculating the tree height of the target tree based on the first angle sensing amount and the first spatial coordinates, the second angle sensing amount and the second spatial coordinates, and the target spatial coordinates based on the principle of triangle.

[0024] Further, the first line formed by the first spatial coordinates and the second spatial coordinates is in parallel with the second line formed by the first end and the second end of the target tree in space.

[0025] Further, the angle obtained by subtracting the first angle sensing amount from the second angle sensing amount is the included angle between the first end and the second end of the target tree and the rotation connection.

[0026] Further, the calculation module, the tree height of the target tree is calculated as follows:

[0027]

[0028] In the formula, H is the tree height of the target tree, L1 is the length of the sighting rod, ∠1 is the first angle sensing amount, ∠2 is the second angle sensing amount, x1 is the horizontal coordinate of the second spatial coordinates, and x2 is the horizontal coordinate of the first spatial coordinates.

[0029] Further, the ends of the first sighting rod and the second sighting rod, and the marking device are provided with UWB modules for sending spatial coordinate information.

[0030] Compared with the prior art, the present application has at least the following beneficial effects:

[0031] (1) The remote tree height measurement method and system based on angle correction can more accurately obtain tree data by solving the measurement error caused by the change of observation angle in complex terrain based on the principle of triangle.

[0032] (2) Only a marking device placed at the end of the target standing tree and an aiming rod held by the surveyor are needed to acquire standing tree data under single-person operation, which greatly reduces the difficulty of operation and improves the measurement efficiency;

[0033] (3) The device is simple and portable. Only a few control coordinates and angle data are needed to obtain the corresponding standing data, which greatly improves the anti-interference ability and reduces the equipment cost. Attached Figure Description

[0034] Figure 1 This is a schematic diagram illustrating the steps of a method for measuring the height of a distant standing tree based on angle correction.

[0035] Figure 2 A schematic diagram of tree height measurement with the tree and person in parallel.

[0036] Figure 3 A diagram illustrating the measurement of tree height for a person on a slope;

[0037] Figure 4 A schematic diagram for measuring the height of a tree on a slope.

[0038] Explanation of reference numerals in the attached diagram: A - Rotary connection point, B - End of the second aiming rod, C - Top of the target tree, D - Bottom of the target tree, E - Target spatial coordinate point, F - End of the first aiming rod. Detailed Implementation

[0039] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0040] Example 1

[0041] To achieve rapid, convenient, and accurate measurement of standing tree diameter at breast height (DBH), such as... Figure 1 As shown, this invention proposes a method for measuring the height of a distant standing tree based on angle correction, including a measuring rod. The measuring rod has a first aiming rod and a second aiming rod rotatably connected to its end, and an angle sensor is provided at the rotatable connection point. The method specifically includes the following steps:

[0042] S1: Fix the measuring rod at the far end, and start controlling each aiming rod to rotate vertically towards the target tree with the vertical state as the initial state, until the first aiming rod obtains the image of the bottom of the target tree;

[0043] S2: Maintain the position of the first aiming rod and record the first angle sensing value of the angle sensor and the first spatial coordinates of the end of the first aiming rod at this time;

[0044] S3: Control the second aiming stick to continue rotating vertically until the second aiming stick acquires an image of the top of the target tree;

[0045] S4: keep the position state of the second aiming rod and record the second angle sensing quantity of the angle sensor at this time and the second space coordinates of the end of the second aiming rod;

[0046] S5: obtain the target space coordinates through the marking device placed at the target standing tree;

[0047] S6: calculate the height of the target standing tree based on the first angle sensing quantity and the first space coordinates, the second angle sensing quantity and the second space coordinates and the target space coordinates according to the triangle related principle.

[0048] Briefly speaking, the device used in the present application mainly includes two parts, one part is a measuring rod held by the investigator, and the other part is a marking device. The marking device mainly includes a UWB device, which can be hung on the target standing tree through the hook on the back of the device. The measuring rod further includes a first aiming rod and a second aiming rod, and the end of the measuring rod is rotatably connected to the first end of the first and second aiming rods. When the first aiming rod and the second standard rod are combined, the measuring rod is straight and in the shape of a character. At the same time, an angle sensor is arranged at the rotating connection for recording the rotation angle of the aiming rod, and a UWB device is also arranged at the end of the aiming rod for obtaining and sending the space coordinates. As can be seen, the overall structure of the device is relatively simple, and the interference items from the outside are few, so it is more convenient and stable to use.

[0049] On the basis of the equipment, the standing tree trunk is approximated as a cuboid, and the measurement can be performed at any position where the tree can be seen. The marking device on the tree serves as the base point (target space coordinates), and the handheld measuring rod constitutes a three-dimensional coordinate system. The UWBs on the two aiming rods are two points (i.e. the first space coordinates and the second space coordinates) in the coordinate system.

[0050] In use, first, fix the measuring rod and any point on the distal end of the target standing tree, and make the aiming rod in a vertical state as the initial state to start vertical rotation towards the target standing tree (assuming that the target standing tree and the measuring rod are in the same x direction in the three-dimensional coordinate system, then the vertical direction is the circumferential motion direction of the aiming rod in the xz plane), and aim at the end point through the aiming rod, so that the breast diameter or height of the target standing tree is clamped between the two aiming rods, thereby displaying the measurement distance on the display screen of the measuring rod. It should be noted that vertical rotation measurement is only applicable to the acquisition of vertical measurement quantities (such as tree height), and if the measurement quantity is horizontal (such as tree diameter), the horizontal rotation should be changed.

[0051] The embodiment takes tree height as an example to explain the measuring method of the device. As known, due to the complexity of the forest land terrain, the relationship between the standing tree and the measurer includes three cases: the person and the tree are parallel to each other on the same horizontal plane, the person is on the slope and the tree is on the slope, and the tree is on the slope and the person is on the slope. This results in that a large error is prone to occur in the measurement of the standing tree data.

[0052] As shown in Figure 2 , Figure 3 , Figure 4 , the point E is the target space coordinate at the marking device, and the point D is the coordinate origin, during the vertical rotation of the sighting rod, if the end F of the first sighting rod obtains the image of the bottom end D of the target standing tree, the angle ∠FAN between the end F of the first sighting rod, the rotation connection A and the vertical downward direction is recorded by manually triggering the button (in the preferred embodiment, the triggering can also be performed through image intelligent recognition), the position state of the first sighting rod is maintained, and then the second sighting rod is continuously rotated, when the end B of the second sighting rod obtains the image of the top end C of the target standing tree, the angle ∠BAN between the end B of the second sighting rod, the rotation connection A and the vertical downward direction is recorded.

[0053] Then according to the space coordinate information of the ends of the first sighting rod and the second sighting rod UWB, it is known that the coordinate of the point B is (x1, y1, z1), the coordinate of the point F is (x2, y2, z2), and the ∠BAF can be obtained through ∠BAN-∠FAN. The ND and MC are horizontal straight lines, and the MN is a vertical straight line parallel to the CD, and the CM, DN and NM vertical lines are drawn through the points B, F and N respectively. The length of AB is L1, and the length of AF is L1, so according to the principle of triangle, it is known that:

[0054] ∵

[0055] ∴GN=L1*sin∠FAN,KM=L1*sin(180 ° -∠FAN-∠BAF)

[0056] ∴

[0057] ∴

[0058]

[0059] That is to say, the tree height measurement of the target standing tree can be automatically obtained by the measuring rod according to the first angle sensing quantity, the first space coordinate, the second angle sensing quantity, the second space coordinate and the target space coordinate through the above formula.

[0060] In order to more intuitively explain the principle of tree height measurement, it can also be expressed as the following formula:

[0061]

[0062] In the formula, H is the target tree height, L1 is the length of the sighting rod, ∠1 is the first angle sensing quantity, ∠2 is the second angle sensing quantity, x1 is the horizontal coordinate of the second spatial coordinate, and x2 is the horizontal coordinate of the first spatial coordinate.

[0063] Embodiment two

[0064] In order to better understand the technical content of the present application, the present application is described in the form of a system structure in this embodiment, a remote tree height measuring system based on angle correction, comprising:

[0065] A measuring rod, the first sighting rod and the second sighting rod being rotatably connected to the first end of the measuring rod at the terminal end, and an angle sensor being arranged at the rotatable connection at the terminal end;

[0066] A marking device, placed at the target tree, for sending the target spatial coordinate;

[0067] When measuring the height of the target tree, the measuring rod is fixed at the remote end, wherein,

[0068] The first sighting rod and the second sighting rod are initially in a vertical state and then vertically rotate towards the target tree, the position of the first sighting rod is kept when the first sighting rod obtains the image of the bottom end of the target tree, and the first angle sensing quantity of the angle sensor at this time and the first spatial coordinate of the terminal end of the first sighting rod are recorded, the position of the second sighting rod is kept when the second sighting rod obtains the image of the top end of the target tree, and the second angle sensing quantity of the angle sensor at this time and the second spatial coordinate of the terminal end of the second sighting rod are recorded;

[0069] Further comprising a calculation module for calculating the target tree height based on the first angle sensing quantity and the first spatial coordinate, the second angle sensing quantity and the second spatial coordinate, and the target spatial coordinate according to the principle of triangle.

[0070] Further, the first connecting line formed by the first spatial coordinate and the second spatial coordinate is in a parallel state with the second connecting line of the first and last ends of the target tree in space.

[0071] Further, the angle obtained by subtracting the first angle sensing quantity from the second angle sensing quantity is the included angle between the first and last ends of the target tree and the rotatable connection at the terminal end.

[0072] Further, in the calculation module, the target tree height calculation is expressed as the following formula:

[0073]

[0074] In the formula, H is the target tree height, L1 is the length of the sighting rod, ∠1 is the first angle sensing quantity, ∠2 is the second angle sensing quantity, x1 is the horizontal coordinate of the second spatial coordinate, and x2 is the horizontal coordinate of the first spatial coordinate.

[0075] Further, the ends of the first sighting rod and the second sighting rod, and the marking device are each provided with a UWB module for sending spatial coordinate information.

[0076] In summary, the remote tree height measurement method and system based on angle correction can solve the measurement error caused by the change of observation angle in complex terrain based on the triangle correlation principle, so that the tree data acquisition can be more accurately realized.

[0077] Only the marking device placed at the target tree end and the sighting rod held by the measurement personnel can realize the tree data acquisition under single-person operation, greatly reducing the operation difficulty and improving the measurement efficiency. The device is simple and portable, and only a few control coordinates and angle data are required to realize the acquisition of the corresponding tree data, greatly improving the anti-interference performance and reducing the equipment cost.

[0078] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, movement condition, etc. between components in a certain specific posture (as shown in the drawings), and if the specific posture changes, the directional indications also change accordingly.

[0079] In addition, the descriptions such as "first", "second", "one" and the like in the present application are only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0080] In the present application, unless otherwise specifically defined and limited, the terms "connection", "fixation" and the like should be understood in a broad sense, for example, "fixation" can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be direct connection, or indirect connection through an intermediate medium; can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically limited. For ordinary skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0081] In addition, the technical solutions among various embodiments of the present application can be combined with each other, but it must be based on that a person skilled in the art can realize, when the combination of technical solutions appears contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope required by the present application.

Claims

1. A method for measuring the height of a distant standing tree based on angle correction, characterized in that, The measuring rod includes a measuring rod with a first aiming rod and a second aiming rod rotatably connected to its end, and an angle sensor is provided at the rotatable connection point. The specific steps include: S1: Fix the measuring rod at the far end, and start controlling each aiming rod to rotate vertically towards the target tree with the vertical state as the initial state, until the first aiming rod obtains the image of the bottom of the target tree; S2: Maintain the position of the first aiming rod and record the first angle sensing value of the angle sensor and the first spatial coordinates of the end of the first aiming rod at this time; S3: Control the second aiming stick to continue rotating vertically until the second aiming stick acquires an image of the top of the target tree; S4: Maintain the position of the second aiming rod and record the second angle sensing value of the angle sensor and the second spatial coordinates of the end of the second aiming rod at this time; S5: Obtain the target spatial coordinates by placing a marker device at the target standing tree; S6: Based on the first angle sensing value and the first spatial coordinates, the second angle sensing value and the second spatial coordinates, the target spatial coordinates, the lengths of the first aiming rod and the second aiming rod, the height of the target standing tree is calculated based on the principle of triangle correlation.

2. The method for measuring the height of a distant standing tree based on angle correction as described in claim 1, characterized in that, The angle obtained by subtracting the first angle from the second angle sensing value is the angle between the head and tail of the target tree and the end rotation connection point.

3. The method for measuring the height of a distant standing tree based on angle correction as described in claim 1, characterized in that, In step S6, the target tree height is calculated using the following formula: In the formula, H is the height of the target tree, the lengths of the first and second aiming rods are equal, both being L1, ∠1 is the first angle sensing value, ∠2 is the second angle sensing value, x1 is the abscissa of the second spatial coordinate, and x2 is the abscissa of the first spatial coordinate.

4. The method for measuring the height of a distant standing tree based on angle correction as described in claim 1, characterized in that, The ends of the first and second aiming rods, as well as the marking device, are all equipped with UWB modules for transmitting spatial coordinate information.

5. A system for measuring the height of a distant standing tree based on angle correction, characterized in that, include: A measuring rod, wherein the ends of the measuring rod are rotatably connected to the heads of the first aiming rod and the second aiming rod, and an angle sensor is provided at the rotatable connection at the end; A marking device, placed at the target tree, is used to transmit the target's spatial coordinates; When measuring the height of a target tree, the measuring rod is fixed at the far end, wherein... The first and second aiming rods start in a vertical position and begin to rotate vertically toward the target tree. When the first aiming rod acquires an image of the bottom of the target tree, the position of the first aiming rod is maintained and the first angle sensing value of the angle sensor and the first spatial coordinate of the end of the first aiming rod are recorded. When the second aiming rod acquires an image of the top of the target tree, the position of the second aiming rod is maintained and the second angle sensing value of the angle sensor and the second spatial coordinate of the end of the second aiming rod are recorded. It also includes a calculation module, which is used to calculate the height of the target tree based on the principle of triangle correlation, according to the first angle sensing value and the first spatial coordinates, the second angle sensing value and the second spatial coordinates, the target spatial coordinates, and the lengths of the first aiming rod and the second aiming rod.

6. The system for measuring the height of a distant standing tree based on angle correction as described in claim 5, characterized in that, The angle obtained by subtracting the first angle from the second angle sensing value is the angle between the head and tail of the target tree and the end rotation connection point.

7. The system for measuring the height of a distant standing tree based on angle correction as described in claim 5, characterized in that, In the calculation module, the target standing tree height is calculated using the following formula: In the formula, H is the height of the target tree, the lengths of the first and second aiming rods are equal, both being L1, ∠1 is the first angle sensing value, ∠2 is the second angle sensing value, x1 is the abscissa of the second spatial coordinate, and x2 is the abscissa of the first spatial coordinate.

8. The system for measuring the height of a distant standing tree based on angle correction as described in claim 5, characterized in that, The ends of the first and second aiming rods, as well as the marking device, are all equipped with UWB modules for transmitting spatial coordinate information.

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