Tree obstacle contradiction detection method based on laser range finder with holder

Abstract

The invention discloses a tree obstacle contradiction detection method based on a laser range finder with a holder, and the method comprises the steps: building a three-dimensional coordinate system, simulating a power transmission line through a catenary formula, and calculating the distance from the laser range finder to a measurement point; the laser range finder is used for measurement according to the measurement angle, and the distance measured by the laser range finder is calculated according to the return value of the laser range finder; comparing the measured value with the value calculated by using the Euclidean formula, if the measured value is greater than the calculated value, determining that there is no shielding object, otherwise, determining that there is a shielding object, and calculating the three-dimensional coordinate of the shielding object; moving the laser range finder along the track, measuring according to the same measurement angle, and detecting whether a shielding object exists within the clearance distance above a measurement point; n measurement points are found along the power transmission line, and each measurement point is measured by using the above method, so that whether there is a shelter within the clearance distance of the whole power transmission line can be detected. The tree obstacle contradiction can be detected more conveniently on the premise that the measurement precision is guaranteed.

Description

Technical Field

[0001] The invention belongs to the field of power facility protection, and in particular relates to a tree obstacle contradiction detection method based on a laser rangefinder with a pan / tilt platform. Background Art

[0002] Electricity is an important support for my country's development. With the rapid development of urbanization and the effective improvement of the ecological environment, the contact between trees and power lines is becoming more and more frequent. According to the "Implementation Rules of the Electric Power Facility Protection Regulations", it is clearly stipulated that "no unit or individual shall plant plants that may endanger the safety of power facilities in the power facility protection area demarcated in accordance with the law". When the distance between the transmission line and the tree is less than the clearance distance, it may cause a short circuit in the transmission line or even cause a fire, causing huge losses to my country's economy. Therefore, detecting tree barrier conflicts is one of the important means to prevent accidents.

[0003] At present, the detection of tree obstacles requires regular inspection and pruning by humans or drones. The safe distance between transmission lines and trees is usually determined based on a combination of factors such as line voltage level, tree type, growth rate, topography, climate conditions, etc. For humans, it is necessary to have a certain understanding of these conditions. For many areas, there are many types of trees, and it is not realistic to have an understanding of the production speed of each type of tree. In addition, it is difficult for humans to reach areas with complex geographical environments, which greatly increases the difficulty of regular inspections and pruning by humans. For drones, there are many blind spots in areas with complex terrain, and these places cannot be detected when using drones for inspection, increasing the hidden dangers of causing accidents. Not only that, it is difficult to control the distance between transmission lines and trees. At present, it can only rely on manual naked eye to identify trees that may exceed the distance, and then use laser rangefinders to measure the distance from trees to transmission lines, resulting in large errors.

[0004] In summary, the solution to the tree barrier contradiction still faces huge challenges. Therefore, providing an accurate measurement method, greatly reducing manual work, and more conveniently detecting the tree barrier contradiction has become a problem to be solved in the existing technology. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a tree obstacle contradiction detection method based on a laser rangefinder with a pan-tilt head, which effectively detects tree obstacle contradictions, and more accurately simulates the sag model of the transmission line and obtains the three-dimensional coordinates of the measuring point by introducing the catenary formula. The three-dimensional coordinates of the laser rangefinder are obtained by combining the track perpendicular to the plane of the transmission line, and the distance from the laser rangefinder to the measuring point is obtained by using the Euclidean formula. The laser rangefinder is then used to measure at a certain angle, and then a right-angled triangle calculation method is constructed to obtain the three-dimensional coordinates of the obstruction to further determine the position of the obstruction. Finally, by changing the measuring angle of the rangefinder and changing the measuring point, accurate measurement of whether there is an obstruction within the clearance distance of the entire transmission line is achieved, effectively solving the problem of inaccurate tree obstacle contradiction detection and waste of manpower and material resources.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A tree obstacle contradiction detection method based on a laser rangefinder with a pan-tilt head comprises the following steps:

[0008] S1. A three-dimensional coordinate system is formed by using the plane where the transmission line is located and the track of the laser rangefinder perpendicular to the plane of the transmission line;

[0009] S2. Use the catenary formula to simulate the transmission line and calculate the coordinates of the maximum sag position;

[0010] S3, move the laser rangefinder to the end point of the transmission line, calculate the coordinates of the measuring point below the maximum sag position according to the coordinates of the maximum sag position and the slope of the tangent at the maximum sag position, calculate the position and measurement angle of the laser rangefinder according to the coordinates of the measuring point and the slope of the tangent at the maximum sag position, and then calculate the distance from the laser rangefinder to the measuring point according to the position of the laser rangefinder and the coordinates of the measuring point using the Euclidean formula;

[0011] S4, using a laser rangefinder to measure according to the measuring angle, and calculating the distance measured by the laser rangefinder according to the return value of the laser rangefinder;

[0012] S5. Compare the measured distance value with the distance value calculated using the Euclidean formula. If the measured distance value is greater than the calculated distance value, there is no obstruction. If the measured distance value is less than the calculated distance value, there is an obstruction on the measurement path, and calculate the three-dimensional coordinates of the obstruction.

[0013] S6. By moving the laser rangefinder along the track and measuring at the same measuring angle, detect whether there is an obstruction within the clearance distance above the measuring point;

[0014] S7. Find N measuring points along the transmission line, calculate the distance from the laser rangefinder to each measuring point using the Euclidean formula, and then use the S4-S6 method to measure to detect whether there are any obstructions within the clearance distance of the entire transmission line.

[0015] To optimize the above technical solutions, the specific measures taken also include:

[0016] Furthermore, S1 is specifically:

[0017] The coordinate origin is selected at the bottom of the tower, the transmission line is placed in the yz plane, and the direction parallel to the laser rangefinder track is taken as the x-axis.

[0018] Furthermore, S2 specifically includes:

[0019] S21. Take the lowest point of the sag as A, and take any point B on the transmission line. Point A is subjected to a horizontal leftward tension T1, and point B is subjected to a tension T2 tangent to the catenary. The angle between T2 and the horizontal direction is θ1. Decompose T2 into a horizontal rightward tension and a vertical upward tension:

[0020] T2 sinθ=G=ssg (2-1)

[0021] T2 cosθ=T1 (2-2)

[0022] In the formula, G represents the weight of the transmission line, s represents the weight per unit length, s represents the length of the transmission line, and g represents the acceleration of gravity;

[0023] From formula 2-1 and formula 2-2, we can get:

[0024]

[0025] Formula 2-3 represents the derivative of all points on the catenary except point A, that is:

[0026]

[0027] dy and dx represent the rate of change in the y and x directions;

[0028] The length s of the transmission line is obtained by integration:

[0029]

[0030] Substituting equation 2-5 into equation 2-4 yields:

[0031]

[0032] Derivative and differential equation 2-6:

[0033]

[0034] Where sinh represents the hyperbolic sine function;

[0035] Finally, differentiate equation 2-7 to obtain the catenary equation:

[0036]

[0037] Wherein, cosh represents the hyperbolic cosine function, and the values ​​of the first constant C1 and the second constant C2 are determined by the selected coordinate system;

[0038] S22. When the pole towers are of equal height, the maximum sag position is at the center between the two pole towers. Substitute the horizontal coordinate value corresponding to the center position into formula 2-8 to obtain the coordinates of the maximum sag position of the transmission line.

[0039] When the two towers are not of the same height, the heights of the two towers are h1 and h2 respectively, and the coordinates of the top points A and B of the two towers are (0, h1) and (l, h2) respectively. According to the coordinates of points A and B, we can calculate:

[0040]

[0041] In the formula, θ2 represents the angle between the line connecting points A and B at the top of the two towers and the horizontal direction. The derivative of the catenary formula is equal to formula 2-9, and the horizontal coordinate of the maximum sag position is calculated:

[0042]

[0043] Substitute the horizontal coordinate of the maximum sag position into formula 2-8 to calculate the coordinate of the maximum sag position of the transmission line.

[0044] Further, in S3, the distance from the laser rangefinder to the measuring point is calculated using the Euclidean formula as follows:

[0045]

[0046] Where L represents the distance from the rangefinder to the measuring point, (0, y2, z3) represents the three-dimensional coordinates of the laser rangefinder, and (0, y1, z2) represents the three-dimensional coordinates of the measuring point.

[0047] Further, in S4, the principle of distance measurement by the laser rangefinder is as follows:

[0048]

[0049] In the formula, S represents the distance from the laser rangefinder to the obstruction; c represents the propagation speed of light in the air; and t represents the time it takes for the laser pulse to travel back and forth between the rangefinder and the target point.

[0050] Further, in S5, the three-dimensional coordinates of the obstruction are:

[0051] x=0

[0052] y=Ssinθ3

[0053] z=Scosθ3

[0054] Where S represents the distance from the laser rangefinder to the obstruction; θ3 represents the angle of the laser rangefinder, and (x, y, z) is the three-dimensional coordinate of the obstruction.

[0055] The beneficial effects of the present invention are:

[0056] (1) The present invention provides a tree obstacle conflict detection method based on a laser rangefinder with a pan / tilt system. A track is added to the original tower to make it more convenient and accurate to measure whether there are obstacles within the clearance distance below the transmission line.

[0057] (2) The catenary formula is introduced to simulate the sag model of the transmission line, which increases the accuracy of calculating the measured target point and greatly improves the measurement accuracy of this method.

[0058] (3) A three-dimensional coordinate system in space is constructed using the two-dimensional plane where the transmission line is located and the track perpendicular to the two-dimensional plane, which makes it easier to calculate the three-dimensional coordinates of the target point and the laser rangefinder, greatly increasing the accuracy of the measurement.

[0059] (4) Derivative the catenary formula, substitute different horizontal coordinate values, and calculate the slope of the tangent at each point, so that the laser rangefinder can measure along this angle.

[0060] (5) Using a pulse laser rangefinder to measure distance enables long-distance measurement, which increases the measurement accuracy of this method.

[0061] (6) Using a laser rangefinder with a pan / tilt head, the height can be continuously adjusted to ensure that the irradiated laser passes the measurement point and moves along the track to detect the same angle. By comparing the measured value and the calculated value, it can be detected whether there are obstacles in the three-dimensional area above the target point being measured.

[0062] (7) The three-dimensional coordinates of the occluder are calculated by constructing a right triangle, which reduces the computational complexity. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 It is a schematic diagram of the catenary;

[0064] Figure 2 It is a schematic diagram of curve integration;

[0065] Figure 3 It is a schematic diagram of the tower height;

[0066] Figure 4 This is a schematic diagram of towers with unequal heights;

[0067] Figure 5 Schematic diagram for establishing a three-dimensional coordinate system

[0068] Figure 6 The structure diagram of the laser rangefinder with pan-tilt

[0069] Figure 7 Schematic diagram for constructing a right triangle

[0070] Figure 8 Schematic diagram of constructing a right triangle after the laser rangefinder moves

[0071] Fig. 9 Schematic diagram for detecting the three-dimensional area above the target point

[0072] Fig.10 Schematic diagram of the locations of N measurement points DETAILED DESCRIPTION

[0073] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0074] Embodiment 1

[0075] The present invention proposes a tree obstacle contradiction detection method based on a laser rangefinder with a pan / tilt platform, comprising the following steps:

[0076] S1, forming a three-dimensional coordinate system using the plane where the power transmission line is located and the track of the laser rangefinder (3) perpendicular to the plane of the power transmission line;

[0077] Use the imaginary plane method to place the bottom transmission line in a two-dimensional plane. Then, according to the two-dimensional plane where the transmission line is located, place the track where the laser rangefinder is located perpendicular to this two-dimensional plane below the transmission line (4) and not lower than the clearance distance at the end point of the transmission line, such as Figure 5 As shown, the origin of the coordinates is selected at the bottom of the tower (1), and the transmission line is placed in the yz plane, so that the catenary formula can be used to simulate the sag model and describe the three-dimensional coordinates of the measuring point below the maximum sag position. The x coordinate of the measuring point is 0, and the direction parallel to the laser rangefinder track (2) is used as the x axis. The purpose is to ensure that when the laser rangefinder moves, the yz coordinate will not change, only the x-axis coordinate will change, and the x coordinate is the distance the laser rangefinder moves.

[0078] S2. For transmission lines, the stiffness is often ignored in engineering and it is regarded as a flexible cable, assuming that its gravity is evenly distributed in the direction of the line connecting the suspension points. Therefore, two mathematical models are used in engineering to analyze sag: the parabola model and the catenary model. However, the natural sag of the transmission line is closer to the catenary, and when the height difference between the two towers is large, using a parabola to simulate the transmission line will greatly increase the error. Therefore, in order to simulate the sag model of the transmission line more accurately, the catenary formula is used to simulate the transmission line. Use the catenary formula to simulate the transmission line and calculate the coordinates of the maximum sag position; S2 specifically includes:

[0079] S21, such as Figure 1 As shown, take the lowest point of the sag as A, and take any point B on the transmission line. Point A is subjected to a horizontal leftward tension T1, and point B is subjected to a tension T2 tangent to the catenary. The angle between T2 and the horizontal direction is θ1. Decompose T2 into a horizontal rightward tension and a vertical upward tension:

[0080] T2 sinθ=G=ssg (2-1)

[0081] T2 cosθ=T1 (2-2)

[0082] In the formula, G represents the weight of the transmission line, s represents the weight per unit length, s represents the length of the transmission line, and g represents the acceleration of gravity;

[0083] From formula 2-1 and formula 2-2, we can get:

[0084]

[0085] Formula 2-3 represents the derivative of all points on the catenary except point A, that is:

[0086]

[0087] dy and dx represent the rate of change in the y and x directions;

[0088] like Figure 2 As shown, a curve can be regarded as composed of several straight line segments of unit length. The length of these straight line segments of unit length (or "arc differential") can be approximated to the length of the entire curve. The length s of the transmission line is obtained by integration:

[0089]

[0090] Substituting equation 2-5 into equation 2-4 yields:

[0091]

[0092] Derivative and differential equation 2-6:

[0093]

[0094] Where sinh represents the hyperbolic sine function;

[0095] Finally, differentiate equation 2-7 to obtain the catenary equation:

[0096]

[0097] Among them, cosh represents the hyperbolic cosine function, and the values ​​of the first constant C1 and the second constant C2 are determined by the selected coordinate system. For example, when the maximum sag position of the transmission line is at the origin of the coordinate axis, the values ​​of C1 and C2 are both 0.

[0098] S22. When the pole towers are of equal height, Figure 3 As shown, the maximum sag position is at the center between the two towers. Substitute the horizontal coordinate value corresponding to the center position into formula 2-8 to obtain the coordinates of the maximum sag position of the transmission line;

[0099] When the two towers are not of equal height, Figure 4 As shown, the heights of the two towers are h1 and h2 respectively, and the coordinates of the top points A and B of the two towers are (0, h1) and (l, h2) respectively. According to the coordinates of points A and B, we can calculate:

[0100]

[0101] In the formula, θ2 represents the angle between the line connecting points A and B at the top of the two towers and the horizontal direction. The derivative of the catenary formula is equal to formula 2-9, and the horizontal coordinate of the maximum sag position is calculated:

[0102]

[0103] Substitute the horizontal coordinate of the maximum sag position into formula 2-8 to calculate the coordinate of the maximum sag position of the transmission line.

[0104] S3. Move the laser rangefinder to the end point of the transmission line, calculate the coordinates of the measuring point below the maximum sag position according to the coordinates of the maximum sag position and the slope of the tangent at the maximum sag position, calculate the position and measurement angle of the laser rangefinder according to the coordinates of the measuring point and the slope of the tangent at the maximum sag position, and then calculate the distance from the laser rangefinder to the measuring point according to the position of the laser rangefinder and the coordinates of the measuring point using the Euclidean formula; in order to be able to adjust the position of the laser rangefinder up and down, a laser rangefinder with a pan / tilt is used, such as Figure 6As shown in the figure, since the laser rangefinder is in the yz plane where the transmission line is located, the x coordinates of the measuring point and the laser rangefinder are both 0. The distance from the laser rangefinder to the measuring point is calculated using the Euclidean formula as follows:

[0105]

[0106] Where L represents the distance from the rangefinder to the measuring point, (0, y2, z3) represents the three-dimensional coordinates of the laser rangefinder, and (0, y1, z2) represents the three-dimensional coordinates of the measuring point.

[0107] S4. Use a laser rangefinder to measure according to the measuring angle, and calculate the distance measured by the laser rangefinder according to the return value of the laser rangefinder. As a high-precision intelligent instrument, the laser rangefinder is widely used in engineering measurement, construction measurement, aerospace measurement, robot navigation, automatic driving and other fields. Compared with traditional rangefinders, traditional rangefinders require a prism to be placed at the target point to be measured to achieve laser ranging with a cooperative target. For complex environments or high temperature and high pressure environments, it is impossible to place a prism at the target point to be measured. Therefore, to achieve distance measurement without a cooperative target is the current mainstream direction of laser rangefinders, which can achieve large-angle and long-distance measurement in harsh environments. There are two main measurement methods for common non-cooperative target laser rangefinders, namely the phase method and the pulse method. Although the phase method has higher accuracy, the measured distance is limited, and the signal requirements for the reflected light are high. For outdoor scenes such as power transmission lines, it is difficult to meet such high requirements. The pulse method is very suitable for measuring long-distance scenes such as power transmission lines because the emitted laser pulses have the characteristics of short duration, concentrated energy and high instantaneous power. Currently, almost all laser rangefinders on the market use the pulse method for distance measurement. The principle of laser rangefinder distance measurement is as follows:

[0108]

[0109] In the formula, S represents the distance from the laser rangefinder to the obstruction; c represents the speed of light in the air; and t represents the time it takes for the laser pulse to travel back and forth between the rangefinder and the target point. When measuring distance, the pulse laser rangefinder emits a pulse laser with a very narrow pulse width. At this time, the timer starts counting, which is counted as t1. When the laser reaches the target, it is reflected. The reflected pulse signal is received by the photoelectric detector of the pulse laser rangefinder. The time is recorded as t2. At this time, t=t2-t1 is used to calculate the flight time of the pulse signal. According to formula 4-1, the distance from the laser rangefinder to the target can be calculated.

[0110] S5. Compare the measured distance value with the distance value calculated using the Euclidean formula. If the measured distance value is greater than the calculated distance value, there is no obstruction. If the measured distance value is less than the calculated distance value, there is an obstruction on the measurement path. Calculate the three-dimensional coordinates of the obstruction. According to the distance from the laser rangefinder to the obstruction and the measurement angle of the laser rangefinder, a right triangle can be constructed, such as Figure 7 As shown, the three-dimensional coordinates of the occluder are:

[0111] x=0

[0112] y=Ssinθ3

[0113] z=Scosθ3

[0114] Where S represents the distance from the laser rangefinder to the obstruction; θ3 represents the angle of the laser rangefinder, and (x, y, z) is the three-dimensional coordinate of the obstruction.

[0115] S6. By moving the laser rangefinder along the track and measuring at the same measurement angle, detect whether there is an obstruction within the clearance distance above the measurement point; when the laser rangefinder starts to move, the x coordinate will change. Since the track is parallel to the x-axis, when moving, the x coordinate of the laser rangefinder is the moving distance, and the calculation method of the yz coordinates does not change, such as Figure 8 The laser rangefinder shown in the figure moves continuously along the track. When the measuring angle is the same, the measuring paths can be made parallel to each other, and it can be detected whether there are any obstructions on a straight line perpendicular to the two-dimensional plane where the transmission line is located and passing through the measuring point. In this way, it can be measured whether there are any obstructions in the three-dimensional area above the measuring point, such as Fig. 9 shown.

[0116] S7. Find N measuring points along the transmission line, calculate the distance from the laser rangefinder to each measuring point using the Euclidean formula, and then use the methods of S4-S6 to measure to detect whether there are any obstructions within the clearance distance of the entire transmission line. Fig.10 As shown in the figure, if the measuring point is on the right side of the maximum sag position, the laser rangefinder on the right side is used to measure it. If the measuring point is on the left side of the maximum sag position, the laser rangefinder on the left side is used to measure it. This ensures that when measuring each measuring point, the measuring path will not illuminate the transmission line. Each measuring point is measured using the above method. Each time a measuring point is changed, the position of the laser rangefinder must be changed M times to detect whether there are any obstructions within the clearance distance under the entire transmission line.

[0117] The above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims

1. A tree obstacle contradiction detection method based on a laser rangefinder with a pan / tilt system, characterized in that: The following steps are involved: S1. A three-dimensional coordinate system is formed by using the plane where the transmission line is located and the track of the laser rangefinder perpendicular to the plane of the transmission line; S2. Use the catenary formula to simulate the transmission line and calculate the coordinates of the maximum sag position; S3, move the laser rangefinder to the end point of the transmission line, calculate the coordinates of the measuring point below the maximum sag position according to the coordinates of the maximum sag position and the slope of the tangent at the maximum sag position, calculate the position and measurement angle of the laser rangefinder according to the coordinates of the measuring point and the slope of the tangent at the maximum sag position, and then calculate the distance from the laser rangefinder to the measuring point according to the position of the laser rangefinder and the coordinates of the measuring point using the Euclidean formula; S4, using a laser rangefinder to measure according to the measuring angle, and calculating the distance measured by the laser rangefinder according to the return value of the laser rangefinder; S5. Compare the measured distance value with the distance value calculated using the Euclidean formula. If the measured distance value is greater than the calculated distance value, there is no obstruction. If the measured distance value is less than the calculated distance value, there is an obstruction on the measurement path, and calculate the three-dimensional coordinates of the obstruction. S6. By moving the laser rangefinder along the track and measuring at the same measuring angle, detect whether there is an obstruction within the clearance distance above the measuring point; S7. Find N measuring points along the transmission line, calculate the distance from the laser rangefinder to each measuring point using the Euclidean formula, and then use the S4-S6 method to measure to detect whether there are any obstructions within the clearance distance of the entire transmission line.

2. The tree obstacle contradiction detection method based on the laser rangefinder with a pan-tilt head according to claim 1, characterized in that: S1 is specifically: The coordinate origin is selected at the bottom of the tower, the transmission line is placed in the yz plane, and the direction parallel to the laser rangefinder track is taken as the x-axis.

3. The tree obstacle contradiction detection method based on the laser rangefinder with a pan-tilt head according to claim 1, characterized in that: S2 specifically includes: S21. Take the lowest point of the sag as A, and take any point B on the transmission line. Point A is subjected to a horizontal leftward tension T1, and point B is subjected to a tension T2 tangent to the catenary. The angle between T2 and the horizontal direction is θ1. Decompose T2 into a horizontal rightward tension and a vertical upward tension: T2sinθ=G=ssg (2-1) T2cosθ=T1 (2-2) In the formula, G represents the weight of the transmission line, s represents the weight per unit length, s represents the length of the transmission line, and g represents the acceleration of gravity; From formula 2-1 and formula 2-2, we get: Formula 2-3 represents the derivative of all points on the catenary except point A, that is: dy and dx represent the rate of change in the y and x directions; The length s of the transmission line is obtained by integration: Substituting equation 2-5 into equation 2-4 yields: Derivative and differential equation 2-6: Where sinh represents the hyperbolic sine function; Finally, differentiate equation 2-7 to obtain the catenary equation: Wherein, cosh represents the hyperbolic cosine function, and the values ​​of the first constant C1 and the second constant C2 are determined by the selected coordinate system; S22. When the pole towers are of equal height, the maximum sag position is at the center between the two pole towers. Substitute the horizontal coordinate value corresponding to the center position into formula 2-8 to obtain the coordinates of the maximum sag position of the transmission line. When the two towers are not of the same height, the heights of the two towers are h1 and h2 respectively, and the coordinates of the top points A and B of the two towers are (0, h1) and (l, h2) respectively. According to the coordinates of points A and B, we can calculate: In the formula, θ2 represents the angle between the line connecting points A and B at the top of the two towers and the horizontal direction. The derivative of the catenary formula is equal to formula 2-9, and the horizontal coordinate of the maximum sag position is calculated: Substitute the horizontal coordinate of the maximum sag position into formula 2-8 to calculate the coordinate of the maximum sag position of the transmission line.

4. The tree obstacle contradiction detection method based on the laser rangefinder with a pan-tilt head according to claim 1, characterized in that: In S3, the distance from the laser rangefinder to the measuring point is calculated using the Euclidean formula as follows: Where L represents the distance from the rangefinder to the measuring point, (0, y2, z3) represents the three-dimensional coordinates of the laser rangefinder, and (0, y1, z2) represents the three-dimensional coordinates of the measuring point.

5. The tree obstacle contradiction detection method based on the laser rangefinder with a pan-tilt head according to claim 1, characterized in that: In S4, the principle of distance measurement by the laser rangefinder is as follows: In the formula, S represents the distance from the laser rangefinder to the obstruction; c represents the propagation speed of light in the air; and t represents the time it takes for the laser pulse to travel back and forth between the rangefinder and the target point.

6. The tree obstacle contradiction detection method based on the laser rangefinder with a pan-tilt head according to claim 1, characterized in that: In S5, the three-dimensional coordinates of the obstruction are: x＝0 y=Ssinθ3 z=Scosθ3 Where S represents the distance from the laser rangefinder to the obstruction; θ3 represents the angle of the laser rangefinder, and (x, y, z) is the three-dimensional coordinate of the obstruction.

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