Warning line superposition method and device

Abstract

The invention discloses a warning line superposition method and device, and relates to the technical field of pipeline inspection, and the method comprises the steps: obtaining real-time data and a pipeline pile number coordinate data set in the inspection process of an unmanned aerial vehicle; determining warning line coordinate points on the two sides of the warning area, and connecting the warning line coordinate points on the two sides of the warning area to obtain a pipeline warning line; determining view field vertex coordinates of the pod camera according to the pod attitude information; determining a view field intersection point of the current view field and the pipeline warning line according to the view field vertex coordinates and the pipeline warning line; and converting the field-of-view intersection point to a pixel coordinate system to obtain pixel warning coordinates, and drawing a connecting line between the pixel warning coordinates in a video frame of the inspection video stream so as to superpose the pipeline warning line to the inspection video stream. The problems that an existing virtual identifier and inspection video superposition method is high in computing power requirement and poor in universality are solved. The inspection efficiency can be improved, the labor cost and the computing power requirement of the processor are reduced, and the universality is high.

Description

Technical Field

[0001] This application relates to the technical field of pipeline inspection, and particularly to a warning line superposition method and device. Background Art

[0002] As an important infrastructure for oil and gas resource transmission, the laying path of long-distance pipelines often needs to cross complex terrains and landforms, especially in mountainous areas and regions spanning large rivers. The traditional manual inspection method faces significant efficiency bottlenecks in complex areas. Not only is the accessibility extremely low, but the inspection operation also faces multiple difficulties. Therefore, using drones for inspection has become a more efficient, accurate, safe, and intelligent ideal choice. However, most current long-distance pipelines adopt underground burial technology. Compared with the traditional overhead laying or surface laying forms, the hidden engineering diseases have stronger spatial closure and dynamic evolution uncertainty. Conventional inspection videos are difficult to lock in on key inspection areas within the field of view.

[0003] In view of the above characteristics, the existing technology uses spatio-temporal coupling visualization presentation technology to superimpose the underground pipe body onto the inspection video in the form of virtual identifiers to help inspectors quickly determine key inspection areas. The existing methods for superimposing virtual identifiers and inspection videos include the method of superimposing a 3D earth model and a video recorded in the Chinese patent with the publication number CN113570720A. This method requires constructing a 3D earth model, which is costly and has poor versatility in the complex and diverse geographical environments of long-distance pipelines. In addition, in practical applications, this method requires operations such as spatial matching and 3D rendering superposition between the 3D earth model and the video, which requires high computing power of the processor. And the method of superimposing a point cloud module and a target line recorded in the Chinese patent with the publication number CN118587394A. This method first needs to establish a point cloud model of the inspection video and then superimpose the target route onto the point cloud model. The constructed point cloud model has a high cost and can only be dedicated to the scene corresponding to the inspection video, with poor versatility. Also, when superimposing the point cloud model and the target route, it is necessary to first load the point cloud model and then perform the superimposition process, which requires high computing power of the processor. Summary of the Invention

[0004] Embodiments of this application provide a warning line superposition method and device, which solve the problems that the existing methods for superimposing virtual identifiers and inspection videos have high requirements for computing power and poor versatility.

[0005] In a first aspect, an embodiment of the present application provides a warning line superposition method, including: obtaining real-time data and a pipeline stake number coordinate dataset during the drone inspection; wherein, the real-time data includes the position information of the drone, the pod attitude information, and the inspection video stream captured by the pod camera; determining the warning line coordinate points on both sides of the warning area according to the pipeline stake number coordinate dataset, and respectively connecting the warning line coordinate points on both sides of the warning area to obtain a pipeline warning line; determining the field of view vertex coordinates of the pod camera according to the pod attitude information; determining the field of view intersection point between the current field of view and the pipeline warning line according to the field of view vertex coordinates and the pipeline warning line; converting the field of view intersection point to the pixel coordinate system to obtain pixel warning coordinates, and drawing a connection line between the pixel warning coordinates in the video frame corresponding to the inspection video stream, so as to superpose the pipeline warning line onto the inspection video stream.

[0006] In combination with the first aspect, in a possible implementation manner, after obtaining the real-time data and the pipeline stake number coordinate dataset during the drone inspection, it further includes: establishing a local rectangular coordinate system with the due east direction as the X-axis, the due north direction as the Y-axis, and the direction perpendicular to the X-Y plane as the Z-axis; using the starting point of the drone as the origin of the local rectangular coordinate system and the geodetic coordinate system; determining the unit change amount of the position information of the drone on different coordinate axes in the local rectangular coordinate system; determining the position of the position information of the drone on the local rectangular coordinate system based on the unit change amount, so as to convert the position information of the drone to the local rectangular coordinate system.

[0007] In combination with the first aspect, in a possible implementation manner, the determining the warning line coordinate points on both sides of the warning area according to the pipeline stake number coordinate dataset includes: grouping two adjacent pipeline stake number coordinates in the pipeline stake number coordinate dataset in pairs to obtain a plurality of coordinate groups; determining the inclination angle of the straight line where the two pipeline stake number coordinates in each coordinate group are located with respect to the coordinate axes to obtain a first angle; determining the warning line coordinate group on one side of the warning area corresponding to the coordinate group according to the first angle and a first distance; wherein, the first distance is determined according to the range of the warning area to be inspected; determining the intersection point of the straight lines where the adjacent warning line coordinate groups are located respectively according to the warning line coordinate group, and using it as the warning line coordinate point on one side of the warning area; determining the warning line coordinate points on the other side of the warning area according to the warning line coordinate points on one side of the warning area by using the midpoint coordinate formula.

[0008] In combination with the first aspect, in a possible implementation manner, the determining of the warning line coordinate group on one side of the warning area corresponding to the coordinate group according to the first angle and the first distance includes: determining a point on the straight line where the two pipeline stake number coordinates in the coordinate group are located as the rotation center, rotating the initial line segment formed by the coordinate group around the rotation center by the first angle to obtain a parallel line segment parallel to the coordinate axis; translating the parallel line segment along the direction of its perpendicular line by the first distance to obtain a translated line segment; rotating the translated line segment around the rotation center by a negative first angle to obtain a rotated line segment; and determining the warning line coordinate group on one side of the warning area corresponding to the coordinate group according to the coordinate points where the two endpoints of the rotated line segment are located.

[0009] In combination with the first aspect, in a possible implementation manner, before determining the field of view vertex coordinates of the pod camera according to the pod attitude information, it includes: converting the pod attitude information in the relative coordinate system to the local rectangular coordinate system to obtain the pod attitude information in the local rectangular coordinate system.

[0010] In combination with the first aspect, in a possible implementation manner, the determining of the warning line coordinate group on one side of the warning area corresponding to the coordinate group according to the first angle and the first distance includes: taking one of the pipeline stake number coordinates in the coordinate group as the first rotation center, rotating the other pipeline stake number coordinate around the first rotation center by the first angle to obtain a first coordinate point; translating the first rotation center and the first coordinate point along the direction perpendicular to the connection line between the first rotation center and the first coordinate point by the first distance to obtain a second rotation center and a second coordinate point; and rotating the second rotation center and the second coordinate point around the first rotation center by a negative first angle to obtain a third rotation center and a third coordinate point, which are the warning line coordinate group on one side of the warning area corresponding to the coordinate group.

[0011] In combination with the first aspect, in a possible implementation manner, the determining of the field of view intersection point between the current field of view and the pipeline warning line according to the field of view vertex coordinates and the pipeline warning line includes: determining the current field of view according to the field of view vertex coordinates; determining the pipeline stake number coordinates in the current field of view according to the current field of view and the position information of the unmanned aerial vehicle; and determining the field of view intersection point between the current field of view and the pipeline warning line according to the pipeline stake number coordinates in the current field of view.

[0012] In combination with the first aspect, in a possible implementation manner, the determining of the field of view vertex coordinates of the pod camera according to the pod attitude information further includes: converting the pod attitude information in the relative coordinate system to the local rectangular coordinate system to obtain the pod attitude information in the local rectangular coordinate system.

[0013] In combination with the first aspect, in a possible implementation manner, the determining the field-of-view vertex coordinates of the pod camera according to the pod attitude information includes: determining the initial field-of-view vertex of the pod camera in its coordinate system according to the pod attitude information; and converting the initial field-of-view vertex to the local rectangular coordinate system to obtain the field-of-view vertex coordinates.

[0014] In combination with the first aspect, in a possible implementation manner, before determining the field-of-view intersection point between the current field of view and the pipeline warning line according to the field-of-view vertex coordinates and the pipeline warning line, it further includes: determining the pipeline stake number interval where the unmanned aerial vehicle is located according to the position information of the unmanned aerial vehicle; determining the moving range of the longitudinal field of view according to the current pitch angle change amount of the pod; and determining the stake number interval for which the field-of-view intersection point needs to be determined currently according to the pipeline stake number interval and the moving range of the longitudinal field of view.

[0015] In combination with the first aspect, in a possible implementation manner, the determining the field-of-view intersection point between the current field of view and the pipeline warning line according to the field-of-view vertex coordinates and the pipeline warning line includes: determining the current field of view according to the field-of-view vertex coordinates; determining the pipeline stake number coordinates within the current field of view according to the current field of view and the position information of the unmanned aerial vehicle; and determining the field-of-view intersection point between the current field of view and the pipeline warning line according to the pipeline stake number coordinates within the current field of view.

[0016] In a second aspect, an embodiment of the present application provides a warning line superimposing device, including: a data acquisition module, configured to acquire real-time data and a pipeline stake number coordinate data set during the inspection of the unmanned aerial vehicle; wherein the real-time data includes the position information of the unmanned aerial vehicle, the pod attitude information, and the inspection video stream captured by the pod camera; a pipeline warning line module, configured to determine the warning line coordinate points on both sides of the warning area according to the pipeline stake number coordinate data set, and connect the warning line coordinate points on both sides of the warning area respectively to obtain a pipeline warning line; a field-of-view vertex coordinate module, configured to determine the field-of-view vertex coordinates of the pod camera according to the pod attitude information; a field-of-view intersection point module, configured to determine the field-of-view intersection point between the current field of view and the pipeline warning line according to the field-of-view vertex coordinates and the pipeline warning line; and a superimposing module, configured to convert the field-of-view intersection point to the pixel coordinate system to obtain pixel warning coordinates, and draw a connection line between the pixel warning coordinates in the video frame corresponding to the inspection video stream, so as to superimpose the pipeline warning line onto the inspection video stream.

[0017] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages: The embodiments of the present application obtain real-time data and pipeline stake number coordinate datasets during the inspection by an unmanned aerial vehicle (UAV); wherein the real-time data includes the position information of the UAV, the pod attitude information, and the inspection video stream captured by the pod camera. Determine the coordinate points of the warning lines on both sides of the warning area according to the pipeline stake number coordinate datasets, and connect the coordinate points of the warning lines on both sides of the warning area respectively to obtain the pipeline warning line. Determine the field-of-view vertex coordinates of the pod camera according to the pod attitude information. Determine the field-of-view intersection points between the current field of view and the pipeline warning line according to the field-of-view vertex coordinates and the pipeline warning line. Convert the field-of-view intersection points to pixel coordinates in the pixel coordinate system, and draw a connection line between the pixel warning coordinates in the video frame corresponding to the inspection video stream, so as to superimpose the pipeline warning line on the inspection video stream. It effectively solves the problems that the existing method of superimposing virtual marks and inspection videos has high requirements for computing power and poor versatility. Furthermore, it enables the staff to more easily focus on the risk areas, improves the inspection efficiency, more easily discovers potential threats to long-distance pipelines, can enhance the work experience of the staff, reduces the labor cost and the computing power requirements of the processor, and has high versatility. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for use in the description of the embodiments of the present application or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 It is a flowchart of a warning line superimposing method provided by an embodiment of the present application; Figure 2 It is a flowchart of determining the coordinate points of the warning lines on both sides of the warning area according to the pipeline stake number coordinate datasets provided by an embodiment of the present application; Figure 3 It is an example diagram of the connection confusion and distortion that occur in the broken line parallel line algorithm provided by an embodiment of the present application; Figure 4 It is an example diagram of the first coordinate group provided by an embodiment of the present application; Figure 5 It is an example diagram of the first coordinate group after rotation and translation provided by an embodiment of the present application; Figure 6 It is an example diagram of the warning coordinate group corresponding to the first coordinate group provided by an embodiment of the present application; Figure 7 It is an example diagram of determining the intersection point of the lines where adjacent warning line coordinate groups are located provided by an embodiment of the present application; Figure 8 It is a schematic diagram of the geometric relationship between the camera field of view and the real-time position of the UAV provided by an embodiment of the present application; Figure 9 An example diagram of a long-distance pipeline provided by an embodiment of the present application and the intersection point of the pipeline warning line and the current field of view; Figure 10 A schematic diagram of the geometric relationship between the coordinate system PxOlPy and m1 provided by an embodiment of the present application; Figure 11 An example diagram of a long-distance pipeline within the current field of view of a pod camera provided by an embodiment of the present application and its corresponding pipeline warning line; Figure 12 A schematic structural diagram of a warning line superposition device provided by an embodiment of the present application. Detailed implementation manners

[0020] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0021] The following explanations are made for some of the technologies involved in the embodiments of the present application to facilitate understanding. They should be considered merely exemplary. Therefore, those of ordinary skill in the art should recognize that various changes and modifications can be made to the embodiments described here without departing from the scope and spirit of the present application. Similarly, for the sake of clarity and conciseness, some descriptions of well-known functions and structures are omitted in the following description.

[0022] Figure 1 It is a flowchart of a warning line superposition method provided by an embodiment of the present application, including steps 101 to 105. Among them, Figure 1 This is only an execution order shown in the embodiment of the present application and does not represent the only execution order of a warning line superposition method. Under the condition that the final result can be achieved, Figure 1 the steps shown can be executed in parallel or in reverse.

[0023] Step 101: Obtain real-time data and pipeline stake number coordinate datasets during the UAV inspection process. In the embodiment of the present application, a two-axis visible light pod camera (with image stabilization function) is mounted on the UAV as a platform to collect real-time data. Among them, the real-time data includes the position information of the UAV, the pod attitude information, and the inspection video stream captured by the pod camera.

[0024] Further, the position information of the drone includes the real-time position of the drone and the real-time attitude of the drone. Among them, the real-time position of the drone is in the geodetic coordinate system, and the real-time attitude of the drone is in the body coordinate system, including the body pitch angle, the body roll angle, and the body yaw angle. The body coordinate system takes the center of gravity of the drone as the origin, the direction of flight along the nose is the X-axis direction, the direction perpendicular to the X-axis and pointing to the right is the Y-axis direction, and the direction perpendicular to the X-Y plane and pointing downward is the Z-axis. The pod attitude information includes the pod attitude angle and the camera field of view angle. Among them, the pod attitude angle is used to describe the spatial orientation of the pod camera relative to the drone body, including the pod pitch angle, the pod roll angle, and the pod yaw angle. The pod attitude angle is in the relative coordinate system, which is the coordinate system of the pod camera relative to the body coordinate system of the drone. Taking the pod camera itself as a reference, the origin is located at the geometric center of the pod camera, and the direction of its coordinate axes is the same as that of the coordinate axes of the body coordinate system. The camera field of view angle is used to describe the spatial range that the lens of the pod camera can capture, including the horizontal field of view angle (the angular range that the pod camera can cover in the horizontal direction) and the vertical field of view angle (the angular range that the pod camera can cover in the vertical direction). The coordinate system of the pod camera is the world coordinate system, and the coordinate system used in its imaging process is the pixel coordinate system, which can be associated with the coordinate system of the pod camera and is used to describe the position of image pixels in the field of view. The pipeline station number coordinate dataset represents the dataset composed of the coordinates of each pipeline station number on the long-distance pipeline. The pipeline station numbers are laid equidistantly on the long-distance pipeline, and pipeline station numbers will be added at special positions, such as crossing sections, elbows, and test piles. This application can use all the pipeline station number coordinates as the pipeline station number coordinate dataset, or only use the pipeline station number coordinates set at the elbows, that is, the coordinates at each inflection point of the long-distance pipeline as the pipeline station number coordinate dataset. The pipeline station number coordinates ignore their height information, with the due east direction as the X-axis and the due north direction as the Y-axis.

[0025] In the embodiment of this application, after obtaining the real-time data and the pipeline station number coordinate dataset during the drone inspection, it further includes: establishing a local rectangular coordinate system with the due east direction as the X-axis, the due north direction as the Y-axis, and the direction perpendicular to the X-Y plane as the Z-axis. Taking the starting point of the drone as the origin of the local rectangular coordinate system and the geodetic coordinate system. Determining the unit change amount of the position information of the drone on different coordinate axes in the local rectangular coordinate system. Based on the unit change amount, determining the position of the position information on the local rectangular coordinate system to convert the position information of the drone to the local rectangular coordinate system.

[0026] Specifically, taking the due east direction as the X-axis, the due north direction as the Y-axis, and the direction perpendicular to the X-Y plane as the Z-axis to establish a local rectangular coordinate system. That is, the Z-axis can be perpendicular to the X-Y plane and point to the sky direction to form a northeast sky coordinate system, or it can be perpendicular to the X-Y plane and point to the ground direction to form a northeast ground coordinate system. In this application, the northeast sky coordinate system is exemplarily used as the local rectangular coordinate system.

[0027] Calculate respectively the unit change amount of longitude corresponding to each meter in the X-axis direction, the unit change amount of latitude corresponding to each meter in the Y-axis direction in the local rectangular coordinate system. The dimension of the Z-axis direction is meters, and the altitude data of the unmanned aerial vehicle can be directly used. That is, convert the dimensions of longitude and latitude into unit change amounts with the unit of meters. Exemplarily, 1° of latitude is approximately 111319.49 meters (slightly varying from the equator to the poles), and the longitude varies with latitude. 1° of longitude is approximately: meters, where represents the corresponding latitude.

[0028] In this application, the positions of the starting points of the unmanned aerial vehicle are respectively selected as the origin of the local rectangular coordinate system and the origin of the longitude-latitude-altitude coordinate system. Then, the conversion method of the position information of the unmanned aerial vehicle on the local rectangular coordinate system is as follows: , .

[0029] In the formula, ( ) represents the position corresponding to the real-time position of the unmanned aerial vehicle on the local rectangular coordinate system, ( ) represents the longitude-latitude value of the real-time position of the unmanned aerial vehicle, represents the unit change amount of longitude, represents the unit change amount of latitude, ( ) represents the origin of the local rectangular coordinate system, ( ) represents the origin of the longitude-latitude-altitude coordinate system.

[0030] Step 102: Determine the coordinate points of the warning lines on both sides of the warning area according to the pipeline stake number coordinate dataset, and connect the coordinate points of the warning lines on both sides of the warning area respectively to obtain the pipeline warning line.

[0031] In the embodiment of the present application, the warning area is the area near the long-distance pipeline that needs to be monitored. It is enclosed by two pipeline warning lines parallel to the long-distance pipeline. The corresponding coordinate points on the pipeline warning line need to be calculated based on the pipeline stake numbers and coordinates of the buried pipeline. Common calculation methods include the polygon expansion algorithm and the broken line parallel line algorithm. Essentially, both of these algorithms are based on the characteristics of vector operations. The polygon expansion algorithm is mainly applied to closed intervals and is mostly suitable for convex polygons. If it is applied to the calculation of the long-distance pipeline warning line, the included angle between adjacent pipelines needs to be constrained. However, the actual long-distance pipeline is buried according to the geographical environment and has a certain degree of randomness. Therefore, the polygon expansion algorithm cannot well adapt to the pipeline layout with random characteristics. When the broken line parallel line algorithm faces two relatively close points, it is prone to confusion in the connection lines, resulting in shape distortion, as shown in Figure 3 shown. If this method is used to solve the pipeline warning line, the distance between the pipeline stake numbers on the long-distance pipeline needs to be constrained, or the upper limit of the safety distance needs to be constrained. Similarly, it is difficult to apply to the pipeline layout buried according to the geographical environment.

[0032] In the embodiment of the present application, the method shown in Figure 2 can solve the problem of randomness of the pipeline stake numbers of the buried pipeline. Figure 2 The steps in can calculate the warning line coordinate points on the pipeline warning line corresponding to the partial warning area of the pipeline stake number coordinates in the currently captured inspection video stream in real time according to the real-time data of the UAV. It is also possible to calculate the warning line coordinate points on the pipeline warning line of the entire warning area according to all the pipeline stake number coordinates in the pipeline stake number coordinate dataset.

[0033] Figure 2 It includes steps 201 to 205, which are specifically as follows.

[0034] Step 201: Group the adjacent pipeline stake number coordinates in the pipeline stake number coordinate dataset in pairs to obtain multiple coordinate groups. In the embodiment of the present application, every two adjacent pipeline stake number coordinates in the pipeline stake number coordinate dataset are divided into a coordinate group, and the middle pipeline stake number coordinate can be shared by two adjacent coordinate groups.

[0035] For example, the pipeline stake number coordinate dataset includes: P00, P01, P02,..., P0n, these n pipeline stake number coordinates, and the divided coordinate groups include: (P00, P01), (P01, P02),..., (P0n-1, P0n), obtaining n-1 coordinate groups.

[0036] Step 202: Determine the inclination angle of the straight line where the two pipeline stake number coordinates in each coordinate group are located relative to the coordinate axis to obtain the first angle. In the embodiment of the present application, calculate the inclination angle of the straight line where the two adjacent pipeline stake number coordinates in different coordinate groups are located relative to the coordinate axis respectively, that is, obtain the first angle.

[0037] Specifically, taking the first coordinate group (P00, P01) as an example, the calculation methods of the first angles of the remaining coordinate groups are the same and will not be elaborated here one by one. The calculation method of the first angle of the coordinate group (P00, P01) is as follows: , Or, .

[0038] In the formula, represents the first angle, ( , ) represents the coordinates of the pipeline stake number coordinate P00, ( , ) represents the coordinates of the pipeline stake number coordinate P01. When or , it means that the straight line where the coordinate group (P00, P01) is located is parallel to the coordinate axis. At this time , no rotation is required.

[0039] The present application can also use the following method to calculate the first angle: , Or, .

[0040] In the formula, represents the first angle, ( , ) represents the coordinates of the pipeline stake number coordinate P00, ( , ) represents the coordinates of the pipeline stake number coordinate P01. When or , it means that the straight line where the coordinate group (P00, P01) is located is parallel to the coordinate axis. At this time , no rotation is required.

[0041] Among them, when the first angle is positive, it means clockwise rotation, and when the first angle is negative, it means counterclockwise rotation.

[0042] Step 203: Determine the warning line coordinate group on one side of the warning area corresponding to the coordinate group according to the first angle and the first distance. In the embodiment of the present application, the width between the two pipeline warning lines is determined according to the range of the warning area to be inspected. The range of the warning area of the present application is exemplarily set to be 20 meters wide, so the first distance is 10 meters. Translate the two pipeline stake number coordinates in the coordinate group along the direction perpendicular to the straight line where the two pipeline stake number coordinates in the coordinate group are located by the first distance to obtain the warning line coordinate group on one side of the warning area corresponding to the coordinate group.

[0043] In an embodiment of the present application, a point is determined as the rotation center on the straight line where the coordinates of two pipeline stake numbers in the coordinate group are located. The initial line segment formed by the coordinate group is rotated by a first angle around the rotation center to obtain a parallel line segment parallel to the coordinate axis. The parallel line segment is translated by a first distance along the direction of its perpendicular line to obtain a translated line segment. The translated line segment is rotated by a negative first angle around the rotation center to obtain a rotated line segment. The coordinate group corresponding to the warning line coordinates on one side of the warning area is determined according to the coordinate points where the two endpoints of the rotated line segment are located.

[0044] Specifically, taking the first coordinate group (P00, P01) as an example, the operation methods of the remaining coordinate groups are the same, so they will not be elaborated here. A point is determined as the rotation center on the straight line where the coordinates of two pipeline stake numbers in the coordinate group (P00, P01) are located. The rotation center can be a coordinate point between the line segments where the coordinates of two pipeline stake numbers in the coordinate group are located, or a point coordinate outside the line segment where the coordinates of two pipeline stake numbers in the coordinate group are located, or one of the pipeline stake number coordinates of the two pipeline stake number coordinates in the coordinate group. Along the rotation center, the initial line segment (i.e., Figure 4 the line segment P00P01 in Figure 5 ) formed by the coordinate group is rotated by a first angle to obtain a parallel line segment parallel to the coordinate axis. As shown, the line segment corresponding to P00 and P01 is the parallel line segment. The parallel line segment is translated by a first distance (i.e., Figure 5 d in Figure 5 ) along the direction of its perpendicular line to obtain a translated line segment (i.e., the line segment P10 P11 ) in Figure 6 . The translated line segment is rotated by a negative first angle around the rotation center to obtain a rotated line segment (i.e., the line segment P10 P11 ) in . The coordinate points where the two endpoints of the rotated line segment are located are the warning line coordinate group (P10 , P11 ) corresponding to the coordinate group on one side of the warning area.

[0045] In another embodiment of the present application, taking one of the pipeline stake number coordinates in the coordinate group as the first rotation center, the other pipeline stake number coordinate is rotated by a first angle around the first rotation center to obtain a first coordinate point. Along the direction perpendicular to the connection line between the first rotation center and the first coordinate point, the first rotation center and the first coordinate point are translated by a first distance to obtain a second rotation center and a second coordinate point. The second rotation center and the second coordinate point are rotated by a negative first angle around the first rotation center to obtain a third rotation center and a third coordinate point, which are the warning line coordinate group corresponding to the coordinate group on one side of the warning area.

[0046] Specifically, taking the first coordinate group (P00, P01) as an example here, the calculation method of the first angle of the remaining coordinate groups is the same and will not be elaborated one by one here.

[0047] Exemplarily, as Figure 4 shown, taking the pipeline stake number coordinate P00 as the first rotation center, rotating another pipeline stake number coordinate P01 around it by the first angle to obtain the first coordinate point P01 , at this time, the straight line where the first rotation center P00 and the first coordinate point P01 are located is parallel to the X-axis. As Figure 5 shown, along the direction perpendicular to the connection line between the first rotation center P00 and the first coordinate point P01 , translate the first rotation center P00 and the first coordinate point P01 by the first distance (i.e., Figure 5 d in it) to obtain the second rotation center P10 and the second coordinate point P11 . That is, translate the first rotation center P00 and the first coordinate point P01 along the Y-axis direction by 10 meters to obtain the second rotation center P10 and the second coordinate point P11 . As Figure 6 shown, rotate the second rotation center P10 and the second coordinate point P11 around the first rotation center P00 by the negative first angle to obtain the third rotation center P10 and the third coordinate point P11 , which is the warning line coordinate group.

[0048] In addition, for the first pipeline stake number coordinate and the last pipeline stake number coordinate in the pipeline stake number coordinate dataset, a warning line coordinate point whose coordinates are flush with it (i.e., the same ordinate or the same abscissa) can also be determined. For example, Figure 6 the warning line coordinate point whose ordinate is flush with the pipeline stake number coordinate P00 in it is P10.

[0049] Specifically, on the straight line where the third rotation center P10 and the third coordinate point P11 are located, determine a warning line coordinate point whose coordinates are flush with the pipeline stake number coordinate P00 (i.e., the same ordinate) to obtain the warning line coordinate point P10.

[0050] Furthermore, as Figure 6 shown, after obtaining the third rotation center P10 and the third coordinate point P11 , the corresponding warning line coordinate point P10 can be determined using the following method. Specifically, as follows: , .

[0051] In the formula, ( , ) represents the coordinates of the warning line coordinate point P10, d represents the first distance, represents the first angle, ([[]] , ) represents the coordinates of the pipeline stake number coordinate P00.

[0052] Similarly, the calculation method of the warning line coordinate point P100 corresponding to the pipeline warning line on the other side of the warning area and the pipeline stake number coordinate P00 is as follows: , .

[0053] In the formula, ([[]] , ) represents the coordinates of the warning line coordinate point P100 on the other side of the warning area, d represents the first distance, represents the first angle, ([[]] , ) represents the coordinates of the pipeline stake number coordinate P00.

[0054] As can be seen from the above, the warning line coordinates P10 and the warning line coordinates P100 are warning line coordinate points that are flush with the Y axis. The warning line coordinate points that are flush with the X axis can be derived from the above formula and will not be elaborated here.

[0055] Those skilled in the art should be aware that the "negative first angle" here is used to describe the rotation direction of the first angle. If the first angle is negative, the negative first angle here indicates clockwise rotation, and if the first angle is positive, the negative first angle indicates counterclockwise rotation.

[0056] Step 204: Determine the intersection points of the lines where the adjacent warning line coordinate groups are located according to the warning line coordinate groups, and use them as the warning line coordinate points on one side of the warning area. In the embodiment of the present application, multiple groups of warning line coordinate groups are obtained according to the above steps 201 to 203, and the intersection points of the lines where the two warning line coordinate points on the adjacent warning line coordinate groups are located are calculated respectively.

[0057] As Figure 7 shown, taking the first coordinate group (P00, P01) and the second coordinate group (P01, P02) as an example, the corresponding warning line coordinate groups on one side of the warning area are (P10 , P11 ) and (P11 , P12 ), according to (P10 , P11 ) and (P11 , P12 ) coordinates to establish straight line equations respectively, and combine the two straight line equations to calculate (P10 , P11 ) and (P11 , P12 ) is the intersection point P11 of the straight line where the warning line and the pipeline stake number coordinate P00 are located. It should be clear to those skilled in the art that if the warning line coordinate point P10 aligned with the pipeline stake number coordinate P00 is calculated in step 203, the warning line coordinate point P10 can also be used here instead of the warning line coordinate point P10. .

[0058] The above method is used to sequentially calculate the intersection of the straight lines where the two warning line coordinate points on each two adjacent warning line coordinate groups are located, and the warning line coordinate points on one side of the warning area can be obtained. That is, the first warning line coordinate point in the first warning line coordinate group, each intersection point, and the second warning line coordinate point in the last warning line coordinate group constitute the warning line coordinate points on one side of the warning area.

[0059] Step 205: According to the warning line coordinate points on one side of the warning area, the warning line coordinate points on the other side of the warning area are determined using the midpoint coordinate formula. In the embodiment of the present application, the pipeline pile number coordinates are used as the midpoint coordinates, and according to the warning line coordinate points on one side of the warning area, the corresponding warning line coordinate points on the other side of the warning area are calculated using the midpoint formula.

[0060] For example, taking the first pipe pile number coordinate P00 as an example, the corresponding warning line coordinate point on one side of the warning area is P10 , then the calculation method of the corresponding warning line coordinate point on the other side is as follows: , .

[0061] In the formula, ( , ) represents the coordinates of the warning line coordinate point on the other side of the pipeline stake coordinate P00, ( , ) represents the coordinate of the pipeline stake number P00, ( , ) indicates the coordinate point P10 of the warning line The coordinates of .

[0062] Using the above method, the corresponding warning line coordinate points on the other side of the warning area are calculated in turn according to the warning line coordinate points on one side of the warning area, and the warning line coordinate points on both sides of the warning area can be obtained. According to the distance between the warning line coordinate points on both sides, the warning line coordinate points on both sides of the warning area are connected in turn to obtain the pipeline warning line.

[0063] Step 103: Determine the field-of-view vertex coordinates of the pod camera based on the pod attitude information. In the embodiment of the present application, before performing Step 103, first convert the pod attitude information in the relative coordinate system to the local rectangular coordinate system to obtain the pod attitude information in the local rectangular coordinate system. Specifically, since the pod attitude information is relative to the real-time attitude of the UAV, it is necessary to convert the pod attitude angles in the pod attitude information to the corresponding local rectangular coordinate system of the UAV. The relationship between the relative coordinate system of the pod and the local rectangular coordinate system of the UAV is relatively simple, and the conversion can be completed according to the geometric relationship, which will not be elaborated here.

[0064] In the embodiment of the present application, determine the initial field-of-view vertex of the pod camera in its coordinate system according to the pod attitude information. Convert the initial field-of-view vertex to the local rectangular coordinate system to obtain the field-of-view vertex coordinates.

[0065] Specifically, as Figure 8 shown, point P is the current position of the pod camera, PP represents the flight direction of the UAV, point Q is the ground projection corresponding to point P, point O1 is the intersection of the optical axis (imaging center line) of the pod camera and the ground, points A, B, C, and D are the intersections of the camera's field of view and the ground at the current height and pose, that is, the initial field-of-view vertices, points E and F are the intersections of the flight direction of the UAV and the field-of-view area, and Yaw represents the yaw angle, that is, the angle between the flight direction of the UAV and the due north direction. Among them, the solid-line three-dimensional coordinate system is the local rectangular coordinate system of the present application, and the dashed-line coordinate system is the ground two-dimensional coordinate system with point Q as the origin.

[0066] First, calculate the coordinates of the initial field-of-view vertices A, B, C, and D in the world coordinate system of the pod camera as follows: , , , , Among them, , , , , .

[0067] In the formula, ([[]] , ) represents the coordinates of the initial field-of-view vertex B in the world coordinate system, PF represents the distance from the current position of the pod camera to the front field-of-view area, that is, the length of PF in Figure 8 , and PE represents the distance from the current position of the pod camera to the rear field-of-view area, that is,Figure 8 The length of PE in represents the height of the pod camera from the ground, that is Figure 8 the length of PQ in represents the complementary angle of the pitch angle of the pod, that is ([[]] ), corresponding to Figure 8 ∠OPQ1 in represents the vertical field of view angle of the pod camera, that is Figure 8 ∠FPE in represents the horizontal field of view angle of the pod camera, that is Figure 8 ∠BPC in , ), represents the coordinates of the initial field of view vertex A in the world coordinate system, ( , ), represents the coordinates of the initial field of view vertex D in the world coordinate system, ( , ), represents the coordinates of the initial field of view vertex C in the world coordinate system. The initial field of view vertex C is symmetric to B with respect to the line where points E and F are located. The initial field of view vertex A is symmetric to D with respect to the line where points E and F are located. In the ground two-dimensional coordinate system, the initial field of view vertices B and C have the same ordinate and opposite abscissas. The initial field of view vertices A and D have the same ordinate and opposite abscissas. In this way, four initial field of view vertices can be obtained.

[0068] The included angle between the axes (Y-axis and y-axis) of the local rectangular coordinate system and the ground two-dimensional coordinate system is the current yaw angle. Therefore, the initial field of view vertices can be converted to the local rectangular coordinate system according to the following formula. Taking the initial field of view vertex B as an example, the calculation method of its corresponding field of view vertex coordinates in the local rectangular coordinate system is as follows: , .

[0069] In the formula, ( , ), represents the field of view vertex coordinates corresponding to the initial field of view vertex B in the local rectangular coordinate system, ( , ), represents the coordinates of the initial field of view vertex B in the world coordinate system, represents the yaw angle, that is Figure 8 the included angle between QF and the Y-axis in , ), represents the coordinates of the projection of the current position of the pod camera on the ground, that is Figure 8 the coordinates of point Q in

[0070] Similarly, the field of view vertex coordinates corresponding to the initial field of view vertices A, C, and D in the local rectangular coordinate system can be obtained, which will not be elaborated here.

[0071] Step 104: Determine the field-of-view intersection points between the current field of view and the pipeline warning line based on the field-of-view vertex coordinates and the pipeline warning line. In the embodiment of the present application, the current field of view is determined based on the field-of-view vertex coordinates. The pipeline stake number coordinates within the current field of view are determined according to the position information of the current field of view and the unmanned aerial vehicle (UAV). The field-of-view intersection points between the current field of view and the pipeline warning line are determined based on the pipeline stake number coordinates within the current field of view.

[0072] Specifically, based on the obtained four field-of-view vertex coordinates, the range of the current field of view can be determined. As Figure 11 shown, it is an example diagram of a long-distance pipeline and its corresponding pipeline warning line within the current field of view of the pod camera.

[0073] According to the straight-line intersection formula, the field-of-view intersection points between the current field of view and the pipeline warning line are calculated, and 4 field-of-view intersection points are obtained. Here, the field-of-view intersection points between the current field of view and the pipeline warning line as well as the long-distance pipeline can also be calculated, and 6 field-of-view intersection points are obtained. If there are pipeline stake number coordinates within the current field of view, 9 field-of-view intersection points are obtained. As Figure 9 shown, P1, P3, P4, and P6 are the 4 field-of-view intersection points between the current field of view and the pipeline warning line, P2 and P5 are the 2 intersection points between the long-distance pipeline and the current field of view, and m1, m2, and m3 are the 3 pipeline stake number coordinates within the current field of view.

[0074] In addition, during the flight of the UAV, the change in the field-of-view area of the pod camera is mainly determined by the flight altitude of the UAV and the pod pitch angle, and the change in the pitch angle has a greater impact on the vertical field-of-view range. When determining whether the pipeline stake number coordinates are within the market area, the process time consumption of the brute-force global loop determination method will increase sharply with the increase in the number of pipeline stake numbers. And the loop determination with a fixed number of pipeline stake numbers cannot fully adapt to the sudden situation of the pitch angle.

[0075] In the embodiment of the present application, optimization can be performed based on the change amount of the pitch angle. That is, before executing step 104, the pipeline stake number interval where the UAV is located can also be determined according to the position information of the UAV. The moving range of the longitudinal field of view is determined according to the current pitch angle change amount of the pod. The stake number interval for which the field-of-view intersection points need to be determined currently is determined according to the pipeline stake number interval and the moving range of the longitudinal field of view.

[0076] Specifically, according to the current real-time position of the UAV, the Euclidean distances between the real-time position and each pipeline stake number coordinate are calculated respectively. The two pipeline stake number coordinates with the smallest Euclidean distance are the pipeline stake number interval where the UAV is currently located. The moving range of the longitudinal field of view is determined according to the current pitch angle change amount of the pod, as follows: .

[0077] In the formula, represents the moving range of the longitudinal field of view, Indicates the current real-time altitude of the UAV, Indicates the current pitch angle, Indicates the change in pitch angle.

[0078] When , it is necessary to determine the stake number intervals of the field of view intersection as follows: .

[0079] When , it is necessary to determine the stake number intervals of the field of view intersection as follows: .

[0080] In the formula, Indicates the stake number interval for determining the field of view intersection, Indicates the stake number interval of the pipeline where the UAV is located. L represents the distance between the current pipeline stake number coordinate and the next pipeline stake number coordinate where the UAV is located, 、 Indicates the number of pipeline stake numbers and represents the number of pipeline stake number coordinates to be traversed. Exemplarily, .

[0081] Based on the position information of the UAV, this application can only obtain several pipeline stake number coordinates near the real-time position of the UAV, and calculate the intersections of several pipeline stake number coordinates and / or their corresponding pipeline warning lines with the current field of view or the longitudinal field of view range. That is, each time only several pipeline stake number coordinates near the real-time position of the UAV are obtained and traversed in sequence until the inspection is completed, which can reduce the data transmission volume and improve the calculation efficiency of the field of view intersection.

[0082] Step 105: Convert the field of view intersection to the pixel coordinate system to obtain the pixel warning coordinates, and draw the connection line between the pixel warning coordinates in the video frame corresponding to the inspection video stream to superimpose the pipeline warning line on the inspection video stream. In the embodiment of this application, taking m1 as an example, the coordinates in the local rectangular coordinate system are converted to the world coordinate system of the pod camera, and the calculation formula is as follows: , .

[0083] In the formula, ( , ) represents the coordinates of m1 in the world coordinate system, ( , ) represents the coordinates of m1 in the local rectangular coordinate system, ([[]] , ) represents the coordinates of the current position of the pod camera projected on the ground, Represents the yaw angle.

[0084] Then, asFigure 10 As shown, a coordinate system PxOlPy is established with the center O1 of the field of view, and the coordinates (X.Pm1, Y.Pm1) of m1 in the coordinate system PxOlPy are calculated. The calculation formula is as follows: , .

[0085] In the formula, ( , ) represents the coordinates of m1 in the world coordinate system, and (X.Pm1, Y.Pm1) represents the coordinates of m1 in the coordinate system PxOlPy. represents the height of the pod camera from the ground, that is, Figure 8 the length of PQ in represents the complementary angle of the pitch angle of the pod, that is, ( ), corresponding to Figure 8 ∠OPQ1 in

[0086] Determine the coordinates (X.m1, Y.m1) of m1 in the corresponding pixel coordinate system according to the dynamic resolution of (X.Pm1, Y.Pm1), specifically as follows: , .

[0087] In the formula, (X.m1, Y.m1) represents the coordinates of m1 in the pixel coordinate system, (X.Pm1, Y.Pm1) represents the coordinates of m1 in the coordinate system PxOlPy, W represents the number of horizontal pixels of the imaging image resolution of the pod camera, represents the horizontal field of view angle of the pod camera, that is, Figure 8 ∠BPC in , ) represents the coordinates of m1 in the world coordinate system, represents the height of the pod camera from the ground, that is, Figure 8 the length of PQ in represents the complementary angle of the pitch angle of the pod, that is, ( ), corresponding to Figure 8 ∠OPQ1 in represents the vertical field of view angle of the pod camera, that is, Figure 8 ∠FPE in

[0088] A pipeline warning line superimposing method disclosed in the present application requires less computing resources and has low requirements for the processor. It can use an on-board processor to generate a pipeline warning line in real time during the UAV inspection process and superimpose it on the inspection video stream. Alternatively, after transmitting the inspection video stream back to the ground end, the pipeline warning line can be calculated at the ground end and superimposed on the inspection video stream according to the pipeline stake number coordinates. Moreover, only by replacing the pipeline stake number coordinate data set for different inspection areas, the migration cost is relatively low and the versatility is relatively high. However, the two methods of superimposing virtual identifiers on the inspection video described in the background technology have relatively high requirements for the computing power of the processor and are difficult to process in real time at the on-board processor end.

[0089] Although the present application provides method operation steps such as in the embodiments or flowcharts, based on routine or non-creative labor, there may be more or fewer operation steps. The step sequence listed in this embodiment is only one of the execution sequences of numerous steps and does not represent the only execution sequence. When the actual device or client product is executed, it can be executed in the order of the method shown in this embodiment or the drawings or executed in parallel (for example, in an environment of parallel processors or multi-threaded processing).

[0090] As Figure 12 shown, an embodiment of the present application further provides a pipeline warning line superimposing device 1000. The device includes: a data acquisition module 1001, a pipeline warning line module 1002, a field of view vertex coordinate module 1003, a field of view intersection point module 1004, and a superimposing module 1005, which are specifically as follows.

[0091] The data acquisition module 1001 is used to acquire real-time data and pipeline stake number coordinate data set during the UAV inspection process. Among them, the real-time data includes the position information of the UAV, the pod attitude information, and the inspection video stream captured by the pod camera.

[0092] The pipeline warning line module 1002 is used to determine the warning line coordinate points on both sides of the warning area according to the pipeline stake number coordinate data set, and connect the warning line coordinate points on both sides of the warning area respectively to obtain the pipeline warning line.

[0093] The field of view vertex coordinate module 1003 is used to determine the field of view vertex coordinates of the pod camera according to the pod attitude information.

[0094] The field of view intersection point module 1004 is used to determine the field of view intersection points of the current field of view and the pipeline warning line according to the field of view vertex coordinates and the pipeline warning line.

[0095] The superimposing module 1005 is used to convert the field of view intersection points into pixel warning coordinates in the pixel coordinate system, and draw a connection line between the pixel warning coordinates in the video frame corresponding to the inspection video stream, so as to superimpose the pipeline warning line on the inspection video stream.

[0096] Some of the modules in the device described in this application can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, classes, etc. that perform specific tasks or implement specific abstract data types. This application can also be practiced in a distributed computing environment where tasks are performed by remote processing devices connected through a communication network. In a distributed computing environment, program modules can be located in local and remote computer storage media including storage devices.

[0097] The devices or modules illustrated in the above application embodiments can be specifically implemented by computer chips or entities, or by products with certain functions. For convenience of description, when describing the above devices, they are divided into various modules according to functions and described separately. When implementing the embodiments of this application, the functions of each module can be implemented in the same or multiple software and / or hardware. Of course, the module that implements a certain function can also be implemented by combining multiple sub-modules or sub-units.

[0098] The methods, devices or modules described in this application can be implemented in the form of computer-readable program code. The controller can be implemented in any suitable manner. For example, the controller can take the form of, for example, a microprocessor or a processor and a computer-readable medium that stores computer-readable program code (such as software or firmware) executable by the (micro)processor, logic gates, switches, application specific integrated circuit (ASIC), programmable logic controller, and embedded microcontroller. Examples of controllers include, but are not limited to, the following microcontrollers: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20, and Silicone Labs C8051F320. The memory controller can also be implemented as part of the control logic of the memory. Those skilled in the art also know that in addition to implementing the controller in the form of pure computer-readable program code, the method steps can be logically programmed to enable the controller to be implemented in the form of logic gates, switches, application specific integrated circuits, programmable logic controllers, and embedded microcontrollers to achieve the same function. Therefore, such a controller can be considered a hardware component, and the devices included therein for implementing various functions can also be regarded as the structures within the hardware component. Or even, the devices for implementing various functions can be regarded as either software modules for implementing the method or structures within the hardware component.

[0099] In addition, the functional modules in the various embodiments of the present invention can be integrated into one processing module, or each module can exist separately, or two or more modules can be integrated into one module.

[0100] The above storage medium includes, but is not limited to, random access memory (English: Random Access Memory; abbreviation: RAM), read-only memory (English: Read-Only Memory; abbreviation: ROM), cache (English: Cache), hard disk drive (English: Hard Disk Drive; abbreviation: HDD), or memory card (English: Memory Card). The memory can be used to store computer program instructions.

[0101] From the description of the above embodiments, those skilled in the art can clearly understand that this application can be implemented by means of software plus necessary hardware. Based on such an understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product, or can also be reflected in the implementation process of data migration. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions for causing a computer device (which can be a personal computer, mobile terminal, server, or network device, etc.) to execute the methods described in various embodiments or some parts of the embodiments of this application.

[0102] The various embodiments in this specification are described in a progressive manner. For the same or similar parts between the various embodiments, reference can be made to each other. Each embodiment focuses on the differences from other embodiments. All or part of this application can be used in many general or special computer system environments or configurations. For example: personal computers, server computers, handheld or portable devices, tablet devices, mobile communication terminals, multi-processor systems, microprocessor-based systems, programmable electronic devices, network PCs, minicomputers, mainframe computers, distributed computing environments including any of the above systems or devices, and so on.

[0103] The above embodiments are only used to illustrate the technical solutions of this application, rather than to limit this application; although this application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of this application.

Claims

1. A warning line superposition method, characterized in that, Including: Obtain real-time data and a pipeline stake number coordinate data set during the drone inspection; wherein, the real-time data includes the position information of the drone, the pod attitude information, and the inspection video stream captured by the pod camera; Determine the warning line coordinate points on both sides of the warning area according to the pipeline stake number coordinate data set, and respectively connect the warning line coordinate points on both sides of the warning area to obtain a pipeline warning line; Determine the field of view vertex coordinates of the pod camera according to the pod attitude information; Determine the field of view intersection point between the current field of view and the pipeline warning line according to the field of view vertex coordinates and the pipeline warning line; Convert the field of view intersection point to the pixel coordinate system to obtain pixel warning coordinates, and draw a connection line between the pixel warning coordinates in the video frame corresponding to the inspection video stream to superimpose the pipeline warning line on the inspection video stream.

2. The method according to claim 1, wherein After obtaining the real-time data and the pipeline stake number coordinate data set during the drone inspection, it further includes: Establish a local rectangular coordinate system with the due east direction as the X-axis, the due north direction as the Y-axis, and the direction perpendicular to the X-Y plane as the Z-axis; Take the starting point of the drone as the origin of the local rectangular coordinate system and the geodetic coordinate system; Determine the unit change amounts of the position information of the drone on different coordinate axes in the local rectangular coordinate system; Determine the position of the position information of the drone on the local rectangular coordinate system based on the unit change amounts to convert the position information of the drone to the local rectangular coordinate system.

3. The method according to claim 1, characterized in that The determining the warning line coordinate points on both sides of the warning area according to the pipeline stake number coordinate data set includes: Group the adjacent pipeline stake number coordinates in the pipeline stake number coordinate data set in pairs to obtain a plurality of coordinate groups; Determine the inclination angle of the straight line where the two pipeline stake number coordinates in each coordinate group are located relative to the coordinate axes to obtain a first angle; Determine the warning line coordinate group on one side of the warning area corresponding to the coordinate group according to the first angle and a first distance; wherein, the first distance is determined according to the range of the warning area to be inspected; Determine the intersection points of the straight lines where the adjacent warning line coordinate groups are located according to the warning line coordinate groups respectively, and use them as the warning line coordinate points on one side of the warning area; According to the warning line coordinate points on one side of the warning area, use the midpoint coordinate formula to determine the warning line coordinate points on the other side of the warning area.

4. The method according to claim 3, characterized in that The determining the warning line coordinate group on one side of the warning area corresponding to the coordinate group according to the first angle and the first distance includes: Determine a point on the straight line where the two pipeline stake number coordinates in the coordinate group are located as the rotation center, rotate the initial line segment formed by the coordinate group around the rotation center by the first angle to obtain a parallel line segment parallel to the coordinate axes; Translate the parallel line segment along the direction of its perpendicular line by the first distance to obtain a translated line segment; Rotate the translated line segment around the rotation center by a negative first angle to obtain a rotated line segment; Determine the warning line coordinate group on one side of the warning area corresponding to the coordinate group according to the coordinate points where the two endpoints of the rotated line segment are located.

5. The method according to claim 3, characterized in that, The determining the warning line coordinate group on one side of the warning area corresponding to the coordinate group according to the first angle and the first distance includes: Taking one of the pipeline stake numbers coordinates in the coordinate group as the first rotation center, and rotating the other pipeline stake number coordinate by the first angle along the first rotation center to obtain a first coordinate point; Along the direction perpendicular to the connection line between the first rotation center and the first coordinate point, translating the first rotation center and the first coordinate point by a first distance to obtain a second rotation center and a second coordinate point; Rotating the second rotation center and the second coordinate point by the negative of the first angle along the first rotation center to obtain a third rotation center and a third coordinate point, which are the coordinate group of the warning line on one side of the warning area corresponding to the coordinate group.

6. The method according to claim 1, characterized in that, The determining the field of view vertex coordinates of the pod camera according to the pod attitude information further includes: Converting the pod attitude information in the relative coordinate system to the local rectangular coordinate system to obtain the pod attitude information in the local rectangular coordinate system.

7. The method according to claim 1, wherein The determining the field of view vertex coordinates of the pod camera according to the pod attitude information includes: Determining the initial field of view vertex of the pod camera in its coordinate system according to the pod attitude information; Converting the initial field of view vertex to the local rectangular coordinate system to obtain the field of view vertex coordinates.

8. The method according to claim 1, wherein Before determining the field of view intersection point between the current field of view and the pipeline warning line according to the field of view vertex coordinates and the pipeline warning line, it further includes: Determining the pipeline stake number interval where the UAV is located according to the position information of the UAV; Determining the moving range of the longitudinal field of view according to the current pitch angle change amount of the pod; Determining the stake number interval where the field of view intersection point needs to be determined currently according to the pipeline stake number interval and the moving range of the longitudinal field of view.

9. The method according to claim 1, wherein The determining the field of view intersection point between the current field of view and the pipeline warning line according to the field of view vertex coordinates and the pipeline warning line includes: Determining the current field of view according to the field of view vertex coordinates; Determining the pipeline stake number coordinates in the current field of view according to the current field of view and the position information of the UAV; Determining the field of view intersection point between the current field of view and the pipeline warning line according to the pipeline stake number coordinates in the current field of view.

10. A warning line superimposing device, characterized in that, It includes: A data acquisition module, configured to acquire real-time data and a pipeline stake number coordinate data set during the UAV inspection; wherein, the real-time data includes the position information of the UAV, the pod attitude information, and the inspection video stream captured by the pod camera; A pipeline warning line module, configured to determine the warning line coordinate points on both sides of the warning area according to the pipeline stake number coordinate data set, and respectively connect the warning line coordinate points on both sides of the warning area to obtain a pipeline warning line; A field of view vertex coordinate module, configured to determine the field of view vertex coordinates of the pod camera according to the pod attitude information; A field of view intersection point module, configured to determine the field of view intersection point between the current field of view and the pipeline warning line according to the field of view vertex coordinates and the pipeline warning line; An overlay module, configured to convert the field of view intersection point to the pixel coordinate system to obtain pixel warning coordinates, and draw a connection line between the pixel warning coordinates in the video frame corresponding to the inspection video stream to overlay the pipeline warning line on the inspection video stream.

Images