UAV overhead power transmission line inspection method and system

Abstract

The present invention proposes a method and system for inspection of overhead power transmission lines by unmanned aerial vehicles, which belongs to the technical field of unmanned aerial vehicle path planning, wherein the method comprises: step 1, reading the equipment parameters required in the database; step 2, establishing a geodetic coordinate system and a pole tower coordinate system, and constructing a mapping relationship between the two; step 3, obtaining inspection detection points according to inspection requirements; step 4, converting the coordinates of the inspection detection points into the geodetic coordinate system based on the mapping relationship; step 5, obtaining the heading angle of the unmanned aerial vehicle according to the inspection detection points; step 6, presetting the inspection starting point, and connecting the inspection path in series based on the heading angle of the unmanned aerial vehicle; step 7, completing the inspection process according to the inspection path. Based on the key parameters of the pole tower and the equipment on the tower, the present invention automatically calculates the shooting points that the unmanned aerial vehicle needs to hover for refined inspection on the pole tower, effectively reducing the cost of capital and manpower investment, greatly reducing the amount of data and calculation, and improving the inspection efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of unmanned aerial vehicle (UAV) path planning, and in particular relates to a method and system for inspecting overhead power transmission lines using UAVs. Background Art

[0002] With the development of computer technology, intelligent equipment has gradually replaced redundant manual working methods. Compared with traditional manual power inspections, the emergence of drone equipment has greatly reduced the investment cost of manual inspections and reduced the accident rate during manual operations.

[0003] In the prior art, when using drones to inspect overhead power transmission lines, three-dimensional point cloud modeling is mainly based on laser radar. The setting of inspection points requires manual setting by clicking on the three-dimensional point cloud processing software, and then the various points are connected in series by humans or software to form the track of the drone's refined inspection. The cost of scanning power line towers by laser radar is 1,500-2,500 yuan / km, and the three-dimensional point cloud data needs to be processed by a computer with a GPU, which increases the hardware investment cost. At the same time, due to the performance of existing drone-mounted laser point cloud equipment, the scanned three-dimensional point cloud data is relatively sparse. When the inspection points are set manually, it is easy to point the position to be inspected on the foreground or background, resulting in track errors and greatly prolonging the track generation time. Summary of the invention

[0004] Purpose of the invention: Propose a method and system for aerial transmission line inspection by drones to solve the above problems in the prior art. Based on the key parameters of the tower and the equipment on the tower, the shooting points where the drone needs to hover for detailed inspection on the tower are automatically calculated, effectively reducing the cost of capital and manpower investment, greatly reducing the amount of data and calculation, and improving inspection efficiency.

[0005] Technical solution: In the first aspect, a method for inspecting overhead power transmission lines using a drone is proposed, and the method specifically comprises the following steps:

[0006] Step 1: Read the required equipment parameters in the database;

[0007] Step 2: Establish a coordinate system and a mapping relationship between coordinate systems according to object-oriented categories; the coordinate system includes: a geodetic coordinate system and a tower coordinate system.

[0008] Among them, the geodetic coordinate system includes: geodetic longitude, geodetic latitude and geodetic height; geodetic longitude is the dihedral angle formed by the geodetic starting meridian plane and the meridian plane where the target point is located. Starting from the starting meridian plane, it is positive to the east, called east longitude, and negative to the west, called west longitude. The floating value range of both is 0 to 180. Geodetic latitude is the angle between the normal line of the ellipsoid surface passing through the target point and the equatorial plane. Starting from the equatorial plane, it is positive to the north, called north latitude, and negative to the south, called south latitude. The floating value range of both is 0 to 90. Geodetic height is the distance from the ground point to the ellipsoid surface along the normal line of the ellipsoid.

[0009] The tower coordinate system includes: x-axis and y-axis. During the establishment process, the GPS coordinates of the tower and the sea level height of 0 are used as the origin, the x-axis is perpendicular to the crossarm direction, and the y-axis is horizontal to the crossarm direction. The positive direction of the x-axis is the direction of the tower toward the next tower in the line, and the positive direction of the y-axis is the direction toward due north.

[0010] Step 3: Obtain inspection points according to inspection requirements;

[0011] Step 4: based on the mapping relationship, the tower coordinates of the inspection point are converted into the geodetic coordinate system;

[0012] Based on the mapping relationship between the earth coordinate system and the tower coordinate system, the UAV inspection coordinate conversion process is realized, which specifically includes the following steps:

[0013] Step 4.1, calculate the offset according to the origin position between the coordinate systems;

[0014] The origin of the geodetic coordinate system is (L 0 ,B 0 ,0), the origin coordinate of the tower coordinate system is (0,0,0) in the original coordinate system, and is (L,B,0) after conversion to the earth coordinate system. Therefore, the coordinate offset obtained is (L 0 -L,B 0 -B,0) = [-L, -B,0];

[0015] Step 4.2, calculate the deflection angle of the coordinate system according to the position information of the front and rear towers;

[0016] Extract the GPS coordinates of the previous and next towers of the current tower, and calculate the deflection angle of the coordinate system of the current tower; let A be the previous tower, B be the next tower, and C be the current tower, and A, B, and C are all translated by the offset of C. When the x-axis and y-axis are the earth coordinate system, and the y′ axis is the tower coordinate system where C is located, convert each inspection point in the tower coordinate system point by point to obtain the coordinate value in the earth coordinate system;

[0017] Step 4.3: According to the offset and the deflection angle of the coordinate system, the inspection point of the drone in the tower coordinate system is converted to the earth coordinate system. The specific conversion expression is:

[0018] (l,b,h)=(-L*cos(θ)+(-B)*sin(θ),-B*cos(θ)-(-L)*sin(θ),h)

[0019] Wherein, (x, y, h) represents the horizontal coordinate, vertical coordinate and height of each inspection point in the tower coordinate system; (l, b, h) represents the longitude, latitude and height of each inspection point in the geodetic coordinate system; (L, B) represents the longitude and latitude of the tower after conversion to the geodetic coordinate system; θ represents the angle between the y-axis of the geodetic coordinate system and the y′-axis of the tower coordinate system of tower C, which is also the heading deflection angle that the UAV needs to adjust at this time.

[0020] Step 5: Obtain the heading angle of the drone according to the inspection points;

[0021] During the inspection process, the heading angle of the drone is obtained based on the geodetic coordinates of all inspection points and the information of the front and rear positions.

[0022] Step 6: preset the inspection starting point, and connect the inspection path in series based on the heading angle of the drone;

[0023] Step 7: Complete the inspection process according to the inspection path.

[0024] In some implementations of the first aspect, when a force majeure wind speed factor occurs, the flight track is set opposite to the wind direction and wind speed, and the process of obtaining the heading angle of the drone when there is wind is:

[0025]

[0026] In the formula, δ represents the heading angle of the UAV when there is wind; represents the heading angle when there is no wind; σ represents the wind direction angle.

[0027] The process of obtaining the flight speed is:

[0028]

[0029] In the formula, represents the flight speed of the drone when there is wind; It indicates the flying speed of the UAV when there is no wind; δ*f indicates the wind speed of the UAV in the current flying direction; f indicates the current wind speed.

[0030] In some implementations of the first aspect, when an obstacle appears during the inspection process that hinders the execution of the inspection task, it is determined whether an obstacle appears by comparing the real-time obstacle avoidance sensor information of the drone with a preset safety distance;

[0031] When the result of the judgment is that an obstacle appears, the drone is controlled to fly a certain distance in the opposite direction of the distance reported by the obstacle avoidance sensor, and move horizontally to the left or right, while obtaining the obstacle avoidance distance reported by the sensor in real time, until the detection result is that the obstacle is bypassed;

[0032] Record the current hovering position of the drone, calculate the position difference between the drone and the inspection shooting point automatically calculated in advance, recalculate the temporary heading angle, adjust the drone heading angle to make the drone fly to the shooting point, and monitor the obstacle avoidance information in real time. When the actual distance is equal to the safe shooting distance, take an image of the current inspection point.

[0033] In the second aspect, a UAV overhead power transmission line inspection system is proposed to implement a power transmission line inspection method. The system specifically includes the following modules:

[0034] A database for storing relevant equipment parameters of overhead transmission lines;

[0035] Data reading module, used to read device parameters in the database;

[0036] Coordinate system construction module, used to establish corresponding coordinate systems according to different object-oriented objects;

[0037] A coordinate value conversion module is used to complete the conversion of different coordinate coefficient values ​​according to the mapping relationship between coordinate systems;

[0038] The detection point acquisition module is used to determine the location of the detection point according to the inspection requirements;

[0039] The heading angle acquisition module is used to determine the position of the detection point according to the detection point acquisition module and calculate the heading angle of the drone;

[0040] The path planning module is used to connect the inspection paths in series at the predetermined inspection starting point according to the heading angle of the UAV and the location of the inspection points.

[0041] The execution module is used to execute the inspection task according to the inspection path generated by the path planning module.

[0042] In a third aspect, a drone overhead power line inspection device is proposed, which includes: a processor and a memory storing computer program instructions.

[0043] The processor reads and executes computer program instructions to implement the transmission line inspection method.

[0044] In a fourth aspect, a computer-readable storage medium is provided, wherein computer program instructions are stored on the computer-readable storage medium. When the computer program instructions are executed by a processor, a transmission line inspection method is implemented.

[0045] Beneficial effects: The present invention proposes a method and system for inspecting overhead power transmission lines using drones. Based on the key parameters of the poles and tower equipment, the system automatically calculates the shooting points that the drone needs to hover for detailed inspections on the poles, effectively reducing the cost of capital and manpower investment, greatly reducing the amount of data and calculations, and improving inspection efficiency. At the same time, in response to the wind speed influence caused by force majeure and obstacles that may occur during actual application, further countermeasures are proposed to effectively improve inspection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 The data processing flow chart of the embodiment of the present invention.

[0047] Figure 2 Schematic diagram of shooting points according to an embodiment of the present invention.

[0048] Figure 3 Schematic diagram of auxiliary points according to an embodiment of the present invention.

[0049] Figure 4 Schematic diagram of point coordinates of an embodiment of the present invention.

[0050] Figure 5 Schematic diagram of the positional relationship between different towers in an embodiment of the present invention.

[0051] Figure 6 The figure is a schematic diagram of the inspection path of an embodiment of the present invention.

[0052] Figure 7 A coordinate diagram for calculating the heading angle of a drone according to an embodiment of the present invention.

[0053] Figure 8 The present invention is a flowchart of performing wind-resistant track correction according to an embodiment of the present invention.

[0054] Fig. 9 The figure is a flow chart of obstacle avoidance measures according to an embodiment of the present invention. DETAILED DESCRIPTION

[0055] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present invention. However, it is apparent to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features well known in the art are not described.

[0056] Embodiment 1

[0057] In one embodiment, a method for inspecting overhead power transmission lines by unmanned aerial vehicles is proposed to solve the problem that the three-dimensional point cloud modeling and trajectory planning of the prior art based on laser radar for refined inspection are high in cost, prone to errors and time-consuming, which affects the overall inspection efficiency. Figure 1 As shown, the method specifically includes the following methods:

[0058] Step 1: Read the required equipment parameters in the database;

[0059] Step 2: Establish the earth coordinate system and the tower coordinate system, and construct the mapping relationship between the two;

[0060] Step 3: Obtain inspection points according to inspection requirements;

[0061] Step 4: based on the mapping relationship, the coordinates of the inspection points are converted into the geodetic coordinate system;

[0062] Step 5: Obtain the heading angle of the drone according to the inspection points;

[0063] Step 6: preset the inspection starting point, and connect the inspection path in series based on the heading angle of the drone;

[0064] Step 7: Complete the inspection process according to the inspection path.

[0065] This embodiment automatically calculates the shooting points where the drone needs to hover for detailed inspection of the tower based on the key parameters of the tower and the equipment on the tower, effectively reducing the investment costs of funds and manpower, greatly reducing the amount of data and calculations, and improving inspection efficiency.

[0066] In a further embodiment, the equipment parameters read from the database are shown in Table 1 below, corresponding to the tower inventory information and equipment technical parameters of the State Grid Corporation of China for the State Grid production management system.

[0067] Table 1

[0068]

[0069] In a further embodiment, in the process of establishing the geodetic coordinate system (L, B, H), the geodetic longitude L of a point on the ground is first set to be the dihedral angle formed by the geodetic starting meridian plane and the meridian plane where the point is located. Starting from the starting meridian plane, it is positive to the east, called east longitude (0~180), and negative to the west, called west longitude (0~180); the geodetic latitude B is the angle between the normal of the ellipsoid passing through the point and the equatorial plane. Starting from the equatorial plane, it is positive to the north, called north latitude (0~90), and negative to the south, called south latitude (0~90); the geodetic height H is the distance from the ground point to the ellipsoid along the normal of the ellipsoid.

[0070] In the process of establishing the tower coordinate system, the GPS coordinates (lng, lat) of the tower and the sea level height of 0 are used as the origin, the x-axis is perpendicular to the crossarm direction, and the y-axis is horizontal to the crossarm direction; the positive direction of the x-axis is the direction of the tower toward the next tower in the line, and the positive direction of the y-axis is the direction toward due north.

[0071] The coordinate conversion process of the UAV inspection based on the mapping relationship between the earth coordinate system and the tower coordinate system specifically includes the following steps: first, the coordinate system offset is calculated; second, the coordinate system deflection angle is calculated according to the position information of the front and rear towers, so as to obtain the heading deflection angle that the UAV needs to adjust at this time; third, the starting point of the inspection path is set, and the inspection detection points are connected in series to obtain the inspection path; from this, according to the two adjacent points in the inspection path, the heading angle of the UAV during the inspection process between the two points is obtained; finally, the inspection of the overhead transmission line is completed according to the inspection trajectory, heading deflection angle and heading angle.

[0072] In a preferred embodiment, the inspection point is used to capture the image data corresponding to the position for subsequent analysis, thereby realizing the determination of the inspection result. Figure 2 As shown, the tower equipment that needs to be photographed at the inspection point includes: ground wire cross arm hanging point, insulator cross arm side hanging point, insulator string, insulator conductor side hanging point. Common pole towers have four layers of cross arms, namely, one layer of ground wire cross arm and three layers of ordinary cross arms. The pole tower is a double circuit, namely, the tower is a symmetrical structure, and the common pole tower insulator is a straight single string, namely, the ordinary cross arm hangs a string of insulators in the vertical direction. Therefore, the shooting point expression of the pole tower in this embodiment is:

[0073] [G w +(I w +I strand +I wireway )*3]*2

[0074] In the formula, G w Indicates the ground wire cross arm hanging point; I w Indicates the hanging point on the cross arm of the insulator; I strand Indicates insulator string; I wireway Indicates the side hanging point of the insulator conductor. Figure 2 As shown, a total of 20 inspection points are selected.

[0075] In a further embodiment, since the shooting point of the drone needs to maintain a safe distance from the target device, in order to facilitate the planning of the inspection track, such as Figure 3 As shown, further increase the number of drone auxiliary points.

[0076] In a preferred embodiment, in the process of using key parameters to inspect overhead transmission lines by drones, assuming that a pole tower is a typical pole tower with 4 layers of cross arms, the total data volume is:

[0077] 64+32+32+…+32+32+32+(32+32+32+32+32)*4+32=992bit

[0078] The 3D point cloud data volume of a pole tower is at the Gb level. It takes about 10 minutes to process the point cloud data of a pole tower on a computer with a typical configuration for processing 3D point clouds. It only takes 0.2 seconds to automatically and quickly model the detailed inspection points of the UAV overhead power transmission line using key parameters on a computer with the same configuration. It takes about 30 minutes to manually plan the track on a pole tower based on the 3D point cloud model. It only takes 2 seconds on a computer using the CPU to automatically and quickly model the detailed inspection points of the UAV overhead power transmission line using key parameters.

[0079] Therefore, the inspection method proposed in this embodiment greatly reduces the data storage volume, data processing volume, data processing time, manual processing time, hardware cost and labor cost.

[0080] Embodiment 2

[0081] In a further embodiment based on the first embodiment, in the tower coordinate system, Figure 4 As shown in the figure, the coordinates of each inspection point are calculated using key equipment parameters as follows: First, auxiliary point 1 is set as the starting point of the route, and the corresponding coordinates are (0, 0, H m +H f +S), coordinates of auxiliary point 2 (0, L l1 +S,H m +H f +S), auxiliary point 3 (0, -L r1 -S,H m +H f +S), then set the left and right ground wire hanging points to cross arm layer 1, i.e. H 1 =H m +H f , and then obtain the coordinates of the left ground line hanging point as (0, L l1 +S,H 1 ), the coordinates of the right ground wire hanging point are (0, -L r1 -S,H 1 ).

[0082] If the line voltage level corresponds to the insulator length J, when the tower type is a straight tower, the coordinate values ​​of the equipment with different layers are obtained in turn through a loop, that is, the height of layer n is H n =H n-1 -D n-1 , the coordinates of the hanging point on the left cross arm of layer n are (0, L ln +S,H n), the coordinates of the insulator string point on the left side of layer n are (0, L ln +S,H n -J / 2), the coordinates of the hanging point of the horizontal wire on the left side of layer n are (0, L ln +S,H n -J), the coordinates of the hanging point on the right cross arm of layer n are (0, -L rn -S,H n ), the coordinates of the insulator string point on the right side of layer n are (0, -L rn -S,H n -J / 2), the coordinates of the hanging point of the horizontal wire on the right side of layer n are (0, -L rn -S,H n -J).

[0083] When the tower type is a tension tower, the coordinate values ​​of the equipment of different layers are obtained in turn by a loop, that is, the height of layer n is H n =H n-1 -D n-1 , the coordinates of the left hanging point on the left cross arm of layer n are (W ln / 2,L ln +S,H n ), the coordinates of the left insulator string point on the left side of layer n are (W ln / 2+J / 2,L ln +S,H n ), the coordinates of the left hanging point of the left horizontal wire of layer n are (W ln / 2+J,L ln +S,H n ), the coordinates of the left and right hanging points on the left cross arm of layer n are (-W ln / 2,L ln +S,H n ), the coordinates of the right insulator string point on the left side of layer n are (-W ln / 2-J / 2,L ln +S,H n ), the coordinates of the right hanging point of the left horizontal wire of layer n are (-W ln / 2-J,L ln +S,H n ), the coordinates of the left hanging point on the right cross arm side of layer n are (-W ln / 2, -L rn -S,H n ), the coordinates of the left insulator string point on the right side of layer n are (-W ln / 2-J / 2, -L rn -S,H n ), the coordinates of the left hanging point of the right horizontal wire of layer n are (-W ln / 2-J, -L rn -S,H n ), the coordinates of the right hanging point on the right cross arm side of layer n are (Wln / 2, -L rn -S,H n ), the coordinates of the right insulator string point on the right side of layer n are (W ln / 2+J / 2, -L rn -S,H n ), the coordinates of the right hanging point of the right horizontal wire of layer n are (W ln / 2+J,-L rn -S,H n ).

[0084] In the preferred embodiment, when the left and right ground wire hanging points are cross arm layer 1, the pseudo codes of different types of tower coordinates are as follows: if type == linear tower:

[0085] for n from 2 to N:

[0086] Layer n height H n =H n-1 -D n-1

[0087] Layer n left cross arm side hanging point coordinates = (0, L ln +S,H n )

[0088] Layer n left insulator string point coordinates = (0, L ln +S,H n -J / 2)

[0089] Layer n left horizontal wire hanging point coordinates = (0, L ln +S,H n -J)

[0090] Layer n right cross arm side hanging point coordinates = (0, -L rn -S,H n )

[0091] Layer n right side insulator string point coordinates = (0, -L rn -S,H n -J / 2)

[0092] Layer n right horizontal wire hanging point coordinates = (0, -L rn -S,H n -J)

[0093] elseif type == tension tower:

[0094] for i from 2 to N:

[0095] Layer n height H n =H n-1 -D n-1

[0096] Layer n left cross arm side left hanging point coordinates = (W ln / 2,L ln +S,H n )

[0097] Layer n left side left insulator string point coordinates = (W ln / 2+J / 2,L ln +S,H n )

[0098] Layer n left horizontal wire left hanging point coordinates = (W ln / 2+J,L in +S,H n )

[0099] Layer n left cross arm side left and right hanging point coordinates = (-W ln / 2,L ln +S,H n )

[0100] Layer n left right insulator string point coordinates = (-W ln / 2-J / 2,L ln +S,H n )

[0101] Layer n left side horizontal wire right hanging point coordinates = (-W ln / 2-J,L ln +S,H n )

[0102] Layer n right cross arm side left hanging point coordinates = (-W ln / 2, -L rn -S,H n )

[0103] Layer n right left insulator string point coordinates = (-W ln / 2-J / 2, -L rn -S,H n )

[0104] Layer n right side horizontal wire left hanging point coordinates = (-W ln / 2-J, -L rn -S,H n )

[0105] Layer n right cross arm right hanging point coordinates = (W ln / 2, -L rn -S,H n )

[0106] Layer n right side right insulator string point coordinates = (W ln / 2+J / 2, -L rn -S,H n)

[0107] Layer n right side horizontal wire right hanging point coordinates = (W ln / 2+J,-L rn -S,H n )

[0108] Embodiment 3

[0109] In a further embodiment based on the first embodiment, in the process of realizing the coordinate conversion process of the drone inspection based on the mapping relationship between the earth coordinate system and the tower coordinate system: the origin of the earth coordinate system is (L 0 , B 0 , 0), the origin coordinates of the tower coordinate system are (0, 0, 0) in the original coordinate system, and are (L, B, 0) after conversion to the earth coordinate system. Therefore, the coordinate offset obtained is (L 0 -L, B 0 -B, 0) = [-L, -B, 0].

[0110] In the process of calculating the deflection angle, since the GPS coordinates of all towers in the line are known, the GPS coordinates of the previous and next towers of the current tower are extracted to calculate the coordinate system deflection angle of the current tower. Let A be the previous tower, B be the next tower, C be the current tower, and A, B, and C are all translated by the offset of C, then the position relationship is as follows: Figure 5 As shown, the x-axis and y-axis are the earth coordinate system, and the y′ axis is the tower coordinate system where C is located.

[0111] Each hovering point in the tower coordinate system is converted point by point to obtain the coordinate value in the earth coordinate system. The specific conversion expression is:

[0112] (l, b, h) = (-L*cos(θ)+(-B)*sin(θ), -B*cos(θ)-(-L)*sin(θ), h)

[0113] Wherein, (x, y, h) represents the horizontal and vertical coordinates and height of each inspection point in the tower coordinate system; (l, b, h) represents the longitude, latitude and height of each inspection point in the geodetic coordinate system; (L, B) represents the longitude and latitude of the tower after conversion to the geodetic coordinate system; θ represents the angle between the y-axis of the geodetic coordinate system and the y′-axis of the tower coordinate system of tower C, which is also the heading deflection angle that the UAV needs to adjust at this time.

[0114] Among them, the calculation expression for obtaining the deflection angle θ is:

[0115]

[0116] Wherein, V represents the angle between the line connecting the GPS coordinates of tower B and tower C and the x-axis of the geodetic coordinate system; U represents the angle between the line connecting the GPS coordinates of tower B and tower C and the y′ axis of the tower coordinate system of tower C.

[0117] When the horizontal and vertical coordinates of tower B in the geodetic coordinate system are (x B ,y B ), the horizontal and vertical coordinates of tower A in the geodetic coordinate system are (x A ,y A )hour,

[0118]

[0119]

[0120]

[0121] Substituting the calculated data into the deflection angle operation expression, the heading deflection angle that the drone needs to adjust at this time can be obtained.

[0122] Embodiment 4

[0123] In a further embodiment based on the first embodiment, Figure 6 As shown, point S is used as the starting point, relay point and end point at the same time. The drone starts from point S, flies to the left or right, and starts to fly to each hovering point in order from high to low, and takes pictures at the refined inspection equipment points. After the lowest point on one side has been photographed, the drone climbs and returns to the relay point S, flies to the other side and completes the same action. After the points on both sides have been photographed, the drone climbs up and returns to the end point S, and goes to the S point corresponding to the next base tower in the line to continue the refined inspection task.

[0124] After obtaining the geodetic coordinates (L, B, H) of all hovering points of the tower, the geodetic coordinates of all points are added to the queue in order according to the set inspection path, and the heading angle of the drone is calculated based on the current position of the drone and the geodetic coordinates of the target point, that is, the direction to fly towards the next hovering point and the direction to face the target device at the hovering point, so as to facilitate camera shooting.

[0125] like Figure 7 As shown, for any two points A(x, y) and B(x′, y′) in the same coordinate system, if their spatial coordinates are known, the heading angle can be calculated.

[0126]

[0127] In the formula, represents the forward heading angle; Indicates the current heading angle.

[0128] Embodiment 5

[0129] In a further embodiment based on the first embodiment, during the inspection process, deep learning target detection technology is used to identify the target at each waypoint to confirm that the drone can capture the target parts that should be captured. At the same time, the drone's heading is fine-tuned by comparing the center coordinates of the detection frame with the center coordinates of the screen.

[0130] Embodiment 6

[0131] In a further embodiment based on the first embodiment, in the process of planning the inspection route, due to the wind factor in the environmental factors, the drone's track often deviates, which makes it impossible to perform precise point flight and stable hovering for refined inspection shooting through the pre-automatically calculated track, thereby affecting the subsequent data analysis effect. Therefore, in the process of planning the inspection route, this embodiment monitors the drone's own GPS in real time, and when hovering at the waypoint, records the deviation of the drone's own hovering position, calculates the wind direction and wind speed, and adjusts the drone's flight speed and track by simulating the drone's flight trajectory in real time to achieve wind-resistant track correction.

[0132] Specifically, Figure 8 As shown in the figure, in the current operating environment, the wind direction angle σ and wind speed f in the geodetic coordinate system are calculated by the difference between the two points of the drone. When the drone flies to the next waypoint, the flight track is set opposite to the wind direction and wind speed, that is, the heading angle of the drone when there is wind:

[0133]

[0134] The flight speed is:

[0135]

[0136] In the formula, δ represents the heading angle of the UAV when there is wind; represents the heading angle when there is no wind; σ represents the wind direction angle; F represents the flight speed of the drone when there is wind; It indicates the flying speed of the UAV when there is no wind; δ*f indicates the wind speed of the UAV in the current flying direction; f indicates the current wind speed.

[0137] Embodiment 7

[0138] In a further embodiment based on the first embodiment, it is easy for a drone to encounter obstacles during flight. The default handling method of most drones after encountering an obstacle is to hover immediately and wait for manual instructions. Since the parameterized automatic calculation of the drone point only uses data, and does not use sensor data such as visible light video streams, the automatically calculated point and track cannot predict the appearance of obstacles.

[0139] Therefore, in actual flight, Fig. 9 As shown, the obstacle avoidance sensor of the drone can be used to obtain the current distance T between the drone and the physical target. Because the safe shooting distance S has been pre-added during the point design and route calculation to prevent the drone from being broken down by high voltage, the real-time obstacle avoidance information of the drone can be compared with the preset safety distance to determine whether an obstacle appears; if the distance value T displayed by the real-time obstacle avoidance information of the drone is less than the preset safety distance S, it means that an obstacle has appeared on the path. At this time, the drone is controlled to fly a certain distance t in the opposite direction of the shortened obstacle avoidance distance to ensure the safety of the drone, and translate to the left or right in the horizontal direction, while detecting the obstacle avoidance distance T in real time. When the obstacle avoidance distance T = t + S, it means that the obstacle has been crossed. Record the hovering position of the drone at this time (L, B, H), and calculate the distance between the drone and the inspection shooting point (L t , B t , H t ) position difference, recalculate the temporary heading angle θ t , adjust the heading angle of the drone to make it head towards the shooting point (L t , B t , H t ) and monitors the obstacle avoidance information T in real time. When T=S, the UAV takes pictures of the inspection points.

[0140] Embodiment 8

[0141] In one embodiment, a drone overhead power transmission line inspection system is proposed, which is used to implement an overhead power transmission line inspection method. The system specifically includes the following modules:

[0142] A database for storing relevant equipment parameters of overhead power transmission lines;

[0143] Data reading module, used to read device parameters in the database;

[0144] Coordinate system construction module, used to establish corresponding coordinate systems according to different object-oriented objects;

[0145] A coordinate value conversion module is used to complete the conversion of different coordinate coefficient values ​​according to the mapping relationship between coordinate systems;

[0146] The detection point acquisition module is used to determine the location of the detection point according to the inspection requirements;

[0147] The heading angle acquisition module is used to determine the position of the detection point according to the detection point acquisition module and calculate the heading angle of the drone;

[0148] The path planning module is used to connect the inspection paths in series at the predetermined inspection starting point according to the heading angle of the UAV and the location of the inspection points.

[0149] The execution module is used to execute the inspection task according to the inspection path generated by the path planning module.

[0150] Embodiment 9

[0151] In one embodiment, a drone overhead power line inspection device is provided, the device comprising: a processor and a memory storing computer program instructions.

[0152] The processor reads and executes computer program instructions to implement the transmission line inspection method.

[0153] Embodiment 10

[0154] In one embodiment, a computer readable storage medium is provided, wherein computer program instructions are stored on the computer readable storage medium.

[0155] When the computer program instructions are executed by the processor, the power transmission line inspection method is implemented.

[0156] As described above, although the present invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the present invention itself. Various changes may be made to it in form and detail without departing from the spirit and scope of the present invention as defined in the appended claims.

Claims

1. A method for inspecting overhead power transmission lines using a drone. It is characterized in that The specific steps include: Step 1: Read the required equipment parameters in the database; Step 2: Establish a coordinate system and a mapping relationship between coordinate systems according to object-oriented categories; the coordinate system includes: a geodetic coordinate system and a tower coordinate system; Step 3: Obtain inspection points according to inspection requirements; Step 4: based on the mapping relationship, the tower coordinates of the inspection point are converted into the geodetic coordinate system; Step 4.1, calculate the offset according to the origin position between the coordinate systems; The origin of the geodetic coordinate system is (L 0 ,B 0 ,0), the origin coordinate of the tower coordinate system is (0,0,0) in the original coordinate system, and is (L,B,0) after conversion to the earth coordinate system. Therefore, the coordinate offset obtained is (L 0 -L,B 0 -B,0) = [-L, -B,0]; Step 4.2, calculate the deflection angle of the coordinate system according to the position information of the front and rear towers; Extract the GPS coordinates of the previous and next towers of the current tower, and calculate the deflection angle of the coordinate system of the current tower; let A be the previous tower, B be the next tower, and C be the current tower, and A, B, and C are all translated by the offset of C. When the x-axis and y-axis are the earth coordinate system, and the y'-axis is the tower coordinate system where C is located, convert each inspection point in the tower coordinate system point by point to obtain the coordinate value in the earth coordinate system; Step 4.3: According to the offset and the deflection angle of the coordinate system, the inspection point of the drone in the tower coordinate system is converted to the earth coordinate system. The specific conversion expression is: (l,b,h)=(-L*cos(θ)+(-B)*sin(θ),-B*cos(θ)-(-L)*sin(θ),h) In the formula, (x, y, h) represents the horizontal coordinate, vertical coordinate and height of each inspection point in the tower coordinate system; (l, b, h) represents the longitude, latitude and height of each inspection point in the geodetic coordinate system; (L, B) represents the longitude and latitude of the tower after conversion to the geodetic coordinate system; θ represents the angle between the y-axis of the geodetic coordinate system and the y'-axis of the tower coordinate system of tower C, which is also the heading deflection angle that the drone needs to adjust at this time; Step 5: Obtain the heading angle of the drone according to the inspection points; Step 6: preset the inspection starting point, and connect the inspection path in series based on the heading angle of the drone; Step 7: Complete the inspection process according to the inspection path.

2. A method for inspecting overhead power transmission lines using a drone according to claim 1, It is characterized in that The geodetic coordinate system includes: geodetic longitude, geodetic latitude and geodetic height; The geodetic longitude is the dihedral angle formed by the geodetic starting meridian plane and the meridian plane where the target point is located. It is measured from the starting meridian plane. It is positive toward the east, called the east longitude, and negative toward the west, called the west longitude. The floating value range of the two is 0 to 180. The geodetic latitude is the angle between the normal of the ellipsoid passing through the target point and the equatorial plane. Starting from the equatorial plane, the latitude is positive toward the north, called the north latitude, and negative toward the south, called the south latitude. The floating range of both values ​​is 0 to 90; The geodetic height is the distance from the ground point to the ellipsoidal surface along the normal line of the ellipsoid; The tower coordinate system includes: an x-axis and a y-axis. During the establishment process, the GPS coordinates of the tower and the sea level height of 0 are used as the origin, the x-axis is perpendicular to the crossarm direction, and the y-axis is horizontal to the crossarm direction. The positive direction of the x-axis is the direction of the tower toward the next tower in the line, and the positive direction of the y-axis is the direction toward due north.

3. A method for inspecting overhead power transmission lines using a drone according to claim 1, It is characterized in that In the process of inspection path planning, a point is first preset as the starting point, and the inspection path of the drone is described by connecting adjacent inspection points in series; During the inspection process, the heading angle of the drone is obtained based on the geodetic coordinates of all inspection points and the information of the front and rear positions.

4. A method for inspecting overhead power transmission lines using a drone according to claim 1, It is characterized in that When obstacles hinder the inspection process, the real-time obstacle avoidance sensor information of the drone is compared with the preset safety distance to determine whether there is an obstacle. When the result of the judgment is that an obstacle appears, the drone is controlled to fly a certain distance in the opposite direction of the distance reported by the obstacle avoidance sensor, and move horizontally to the left or right, while obtaining the obstacle avoidance distance reported by the sensor in real time, until the detection result is that the obstacle is bypassed; Record the current hovering position of the drone, calculate the position difference between the drone and the inspection shooting point automatically calculated in advance, recalculate the temporary heading angle, adjust the drone heading angle to make the drone fly to the shooting point, and monitor the obstacle avoidance information in real time. When the actual distance is equal to the safe shooting distance, take an image of the current inspection point.

5. A UAV overhead power transmission line inspection system, used to implement the power transmission line inspection method according to any one of claims 1 to 4, It is characterized in that Specifically includes the following modules: A database for storing relevant equipment parameters of overhead transmission lines; Data reading module, used to read device parameters in the database; Coordinate system construction module, used to establish corresponding coordinate systems according to different object-oriented objects; A coordinate value conversion module is used to complete the conversion of different coordinate coefficient values ​​according to the mapping relationship between coordinate systems; The detection point acquisition module is used to determine the location of the detection point according to the inspection requirements; The heading angle acquisition module is used to determine the position of the detection point according to the detection point acquisition module and calculate the heading angle of the drone; The path planning module is used to connect the inspection paths in series at the predetermined inspection starting point according to the heading angle of the UAV and the location of the inspection points. The execution module is used to execute the inspection task according to the inspection path generated by the path planning module.

6. A drone overhead power transmission line inspection device, It is characterized in that The device comprises: a processor and a memory storing computer program instructions; The processor reads and executes the computer program instructions to implement the power transmission line inspection method according to any one of claims 1 to 4.

7. A computer-readable storage medium, It is characterized in that The computer-readable storage medium stores computer program instructions, and when the computer program instructions are executed by a processor, the power transmission line inspection method according to any one of claims 1 to 4 is implemented.

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