An overhead wire spatial visual positioning module and positioning method

Abstract

The application discloses an overhead wire space visual positioning module and a positioning method, which comprise a CCD camera, multiple laser measuring sensors and a control unit, the multiple laser measuring sensors are respectively located on the two sides of the CCD camera; the control unit comprises a controller and a control platform which is in wireless communication connection with the controller, multiple motors which can respectively drive the visual positioning module to rotate or move in the horizontal direction are arranged in the control platform; the position relationship between the visual positioning module and the overhead wire is measured through the CCD camera and the laser measuring sensors, the position of the visual positioning module is driven through the motors in the control platform, the position of the overhead wire is accurately measured and positioned, so that the position of the wire can be found by the working tool, and the wire is prevented from being damaged; in addition, the CCD camera can be used for measurement and monitoring, and has a wider use.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of power distribution lines, in particular to an overhead power line spatial visual positioning module and positioning method. BACKGROUND

[0002] Live working refers to the maintenance, testing, modification and replacement of defective equipment on high-voltage electrical equipment without power interruption to ensure that the entire power grid is in a non-power-off state; safety must be considered first in power distribution live working; power distribution facilities are dense, making the range of live working personnel narrow, and the working personnel work within a limited operating range, combined with the invisibility of high voltage and the work of the working personnel in high places, the working personnel often make some dangerous moves, which can easily touch other power facilities at different potentials; therefore, if safety measures are not comprehensive, work methods are not standardized, and tools are not used properly, single-phase grounding, phase-to-phase short circuit, and even personal injury accidents can easily occur; therefore, using advanced work tools can not only reduce the labor intensity of the working personnel and save work time, but also greatly improve the safety of live working; the prior art has a live working robot with multiple function expansion support, but it cannot accurately measure the position of the overhead power line, and the precise positioning of the position of the power line will cause the working tool carried by the robot to work incorrectly on the power line, so an overhead power line spatial visual positioning module and positioning method need to be designed. SUMMARY

[0003] The present application provides an overhead power line spatial visual positioning module and positioning method that can solve the problems identified in the background art.

[0004] An overhead power line spatial visual positioning module includes a CCD camera, multiple laser measurement sensors, and a control unit, with the multiple laser measurement sensors located on both sides of the CCD camera;

[0005] The control unit includes a controller and a control platform in wireless communication with the controller, and the control platform is provided with multiple motors that can respectively drive the visual positioning module to rotate or move horizontally.

[0006] A positioning method for positioning by an overhead power line spatial visual positioning module includes the following steps:

[0007] Step one: the visual positioning module collects two-dimensional scene image data and spatial coordinate position information data at a predetermined spatial position through the CCD camera;

[0008] Step two: image processing and calculation are performed on the collected two-dimensional scene image data to obtain two-dimensional angle deflection information of the overhead power line in the two-dimensional scene image data;

[0009] Step three: the controller drives the motor according to the two-dimensional angle deflection information of the overhead wire obtained in step two, so that the visual positioning module rotates, and the horizontal direction of the visual positioning module is parallel to the overhead wire;

[0010] Step four: two-dimensional scene image data and spatial coordinate information data are collected again, and a fitting straight line is obtained according to the image processing method in step two, and the center coordinate position of the image data is calculated. The longitudinal pixel deviation between the fitting straight line and the center of the image data is calculated through the pixel difference value between the longitudinal coordinates of the fitting straight line and the center of the image data. The motor pulse step number is converted according to the image pixel and motor pulse proportion relationship, and the controller drives the motor to move the visual positioning module radially, so that the center position of the visual positioning module coincides with the axis of the overhead wire.

[0011] Step five: the two laser measurement sensors on the visual positioning module measure the distance of the overhead wire, and the axial deflection angle of the overhead wire relative to the visual positioning module is calculated through the distance measurement difference of the two laser measurement sensors. The controller drives the motor to rotate the visual positioning module by the corresponding deflection angle, so that the visual positioning module is parallel to the overhead wire in the side view direction.

[0012] Preferably, the image processing method is:

[0013] (1) The two-dimensional scene image collected by the CCD camera is subjected to gray scale processing, and the formula used is:

[0014] gray = 0.39 * R + 0.5 * G + 0.11 * B;

[0015] (2) The edge detection processing is performed on the gray scale image to obtain the outline of the overhead wire in the image, and the Sobel edge detection operator is used:

[0016] First, weighted average is performed, and then differential operation is performed, and the calculation method of the operator is as follows:

[0017] Δ x f(x,y) = [f(x-1,y+1) + 2f(x,y+1) + f(x+1,y+1)] - [f(x-1,y-1) + 2f(x,y-1) + f(x+1,y-1)];

[0018] Δ y f(x,y) = [f(x-1,y-1) + 2f(x-1,y) + f(x-1,y+1)] - [f(x+1,y-1) + 2f(x+1,y) + f(x+1,y+1)];

[0019] The gradient size is calculated in combination with the horizontal and vertical gradient approximations of the pixels in the image:

[0020]

[0021] (3) using Hough transform to extract features of the overhead wire, extracting the overhead wire edge and fitting into a straight line, wherein the Hough transform polar coordinate operation is:

[0022] r=x cos θ+y sin θ;

[0023] wherein, r represents the polar radius; θ represents the polar angle;

[0024] (4) obtaining the fitting straight line two end points P1(x1, y1), P2(x2, y2), calculating the angle α of the fitting straight line relative to the horizontal plane of the visual positioning module; the formula for calculating the angle α is:

[0025] α=tan -1 [(y1-y2) / (x1-x2)]×(180 / π).

[0026] Preferably, the formula for calculating the motor pulse step number is:

[0027] Pl=P I / K;

[0028] wherein, Pl is the motor pulse number; P I is the longitudinal pixel deviation value of the fitting straight line and the center coordinate; K is the image pixel and motor pulse proportional relationship.

[0029] Preferably, the calculation method of the axial deflection angle of the overhead wire relative to the visual positioning module is:

[0030] By measuring the distance between the two laser measurement sensor center axes and the distance difference between the two laser measurement sensors and the overhead wire, the arctangent function is used to calculate the axial deflection angle of the overhead wire relative to the visual positioning module, wherein the calculation formula is:

[0031] β=tan -1 ((L2 / L1) / D)×(180 / π);

[0032] wherein, L1 is the distance between the visual positioning module and the overhead wire measured by the laser measurement sensor No. 1;

[0033] L2 is the distance between the visual positioning module and the overhead wire measured by the laser measurement sensor No. 2;

[0034] D is the distance between the two laser measurement sensor center axes;

[0035] β is the angle distance between the visual positioning module and the overhead wire;

[0036] Pi is the ratio of the circumference of a circle to its diameter.

[0037] Compared with the prior art, the present application has the beneficial effects that the CCD camera cooperates with the laser measuring sensor to accurately measure the position of the overhead power line, corrects the positional relationship between the visual positioning module and the overhead power line, and makes the visual positioning module parallel to the overhead power line.

[0038] After the visual positioning module accurately positions the position of the overhead power line, the working tool on the live-line working robot is guided to work on the power line, so that the situation that the working tool cannot normally work due to the failure to find the position of the power line is prevented.

[0039] The CCD camera can measure and monitor at the same time, and has more uses.

[0040] The CCD camera is fast, and can measure multiple times in one action. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 It is a structural schematic diagram of the visual positioning module of the present application.

[0042] Figure 2 It is a schematic diagram of the internal structure of the visual positioning module of the present application.

[0043] Figure 3 It is a schematic diagram of the gray scale processing of a two-dimensional scene image.

[0044] Figure 4 It is a sobel edge detection schematic diagram.

[0045] Figure 5 It is a Hough transform polar coordinate diagram.

[0046] Figure 6 It is a Hough transform space schematic diagram.

[0047] Figure 7 It is a Hough transform detection structure schematic diagram.

[0048] Figure 8 It is a coordinate diagram of the end point of the fitted straight line.

[0049] Figure 9 It is an edge detection result diagram after the position of the visual positioning module is adjusted.

[0050] Figure 10 It is a Hough transform fitted straight line diagram after the position of the visual positioning module is adjusted.

[0051] Figure 11 It is an axial deflection angle diagram of the overhead power line and the visual positioning module.

[0052] Explanation of reference signs:

[0053] 1-CCD camera, 2-laser measurement sensor, 3-wireless module, 4-battery, 5-controller. Detailed Implementation

[0054] The following detailed description of a specific embodiment of the present invention is provided in conjunction with the accompanying drawings. However, it should be understood that the scope of protection of the present invention is not limited to the specific embodiment.

[0055] like Figures 1 to 11 As shown, an embodiment of the present invention provides a spatial visual positioning module for overhead power lines, including a CCD camera 1, multiple laser measurement sensors 2, and a control unit, wherein the multiple laser measurement sensors 2 are respectively located on both sides of the CCD camera 1;

[0056] The control unit includes a controller 5 and a control platform wirelessly connected to the controller 5. The control platform is equipped with multiple motors that can drive the visual positioning module to rotate or move in the horizontal direction.

[0057] Using a motor to change the position of the vision positioning module is not the only structure; stroke-variable structures such as cylinders and hydraulic cylinders can also be used. The vision positioning module is set on the control platform, and the motor drives the vision positioning module to move and rotate on the control platform. Specifically, the output end of the motor is connected to a turntable, and the vision positioning module is set on this turntable. The motor can drive the vision positioning module to rotate a certain angle. Another motor is connected to the vision positioning module through driving an electric push rod, so as to drive the vision positioning module to move radially and adjust the angle between the vision positioning module and the horizontal direction. Such drive mechanisms also exist in the prior art, so they will not be described in detail here.

[0058] The controller 5 transmits signals to multiple motors, CCD cameras, and laser measurement sensors on the control platform via the wireless module 3. The wireless module 3 can be a Bluetooth module, a Wi-Fi module, a 4G / 5G communication module, etc., and the specific choice can be made according to the application.

[0059] The visual positioning module is installed on the robot. Multiple motors on the control platform can drive the visual positioning module to rotate or move in the horizontal direction. The specific connection method is existing technology, so it will not be described in detail here.

[0060] A positioning method using an overhead power line spatial visual positioning module includes the following steps:

[0061] Step 1: The robot carrying the visual positioning module arrives at the preset spatial location. The visual positioning module collects two-dimensional scene image data and spatial coordinate position information data at the preset spatial location through CCD camera 1.

[0062] Step two: image processing and calculation on the collected two-dimensional scene image data to obtain the two-dimensional angle deflection information of the overhead wire in the two-dimensional scene image data, so as to provide data support for the correction of the robot position, and the specific implementation method is as follows:

[0063] (1) The two-dimensional scene image collected by the CCD camera 1 is processed into a gray image (as shown in Figure 3 ), and the formula used is:

[0064] gray = 0.39 * R + 0.5 * G + 0.11 * B;

[0065] (2) The edge detection processing (as shown in Figure 4 ) is performed on the gray image to obtain the contour graph of the overhead wire in the image, and the Sobel edge detection operator is used:

[0066] First, weighted average is performed, and then differential operation is performed, and the calculation method of the operator is as follows:

[0067] Δ x f(x,y) = [f(x-1,y+1) + 2f(x,y+1) + f(x+1,y+1)] - [f(x-1,y-1) + 2f(x,y-1) + f(x+1,y-1)];

[0068] Δ y f(x,y) = [f(x-1,y-1) + 2f(x-1,y) + f(x-1,y+1)] - [f(x+1,y-1) + 2f(x+1,y) + f(x+1,y+1)];

[0069] The gradient size is calculated in combination with the horizontal and vertical gradient approximations of the pixels in the image:

[0070]

[0071] (3) The Hough transform is used to extract the features of the overhead wire (as shown in Figure 5 ), the overhead wire edge is extracted and fitted into a straight line, and the Hough transform polar coordinate operation is used:

[0072] r = x cos θ + y sin θ;

[0073] Wherein, r represents the polar radius; θ represents the polar angle;

[0074] Figure 6 The points in Figure 7 are the Hough transform peak values, is the Hough transform detection result;

[0075] Figure 8(As shown), calculate the angle α between the fitted line and the horizontal plane of the visual positioning module; the formula for calculating angle α is:

[0076] α = tan -1 [(y1-y2) / (x1-x2)]×(180 / π);

[0077] Step 3: The controller 5 drives the motor to rotate the visual positioning module based on the two-dimensional angle deflection information of the overhead power line obtained in Step 2 (i.e., the angle between the overhead power line and the horizontal plane of the visual positioning module), so that the horizontal direction of the visual positioning module is parallel to the overhead power line.

[0078] Step 4: Collect 2D scene image data and spatial coordinate information data again (e.g., Figure 9 As shown, this is the edge detection result of the two-dimensional scene image after the motor-driven vision positioning module moves. The image center is located and marked with a crosshair. The fitted line is obtained according to the image processing method in step two, and the center coordinate position of the image data is calculated. The vertical pixel deviation between the fitted line and the image data center is calculated by the pixel difference between the vertical coordinate of the fitted line and the vertical coordinate of the image data center. Figure 10 (Fit a straight line graph for Hough transform), calculate the number of motor pulse steps based on the ratio of image pixels to motor pulses, and drive the motor with controller 5 to move the visual positioning module radially so that the center position of the visual positioning module coincides with the axis of the overhead power line.

[0079] The formula for calculating the number of motor pulse steps is:

[0080] Pl = P I / K;

[0081] Where Pl is the number of motor pulses; P I The vertical pixel deviation between the fitted straight line and the center coordinates; K is the ratio of image pixels to motor pulses;

[0082] Step 5: The overhead power line is measured by two laser measurement sensors on the vision positioning module. The axial deflection angle of the overhead power line relative to the vision positioning module is calculated by the distance difference measured by any two laser measurement sensors. The drive motor is controlled to make the vision positioning module rotate by the corresponding deflection angle so that the vision positioning module and the overhead power line are parallel in the side view direction.

[0083] like Figure 11 As shown, the method for calculating the axial deflection angle of the overhead power line relative to the visual positioning module is as follows:

[0084] The axial deflection angle of the overhead wire relative to the visual positioning module is calculated by the arctangent function through the distance between the two laser measuring sensors 2 center axes and the difference between the distances measured by the two laser measuring sensors 2 between the visual positioning module and the overhead wire, wherein the calculation formula is:

[0085] β=tan -1 ((L2 / L1) / D)×(180 / π);

[0086] Wherein, L1 is the distance between the visual positioning module and the overhead wire measured by the laser measuring sensor No. 1;

[0087] L2 is the distance between the visual positioning module and the overhead wire measured by the laser measuring sensor No. 2;

[0088] D is the distance between the two laser measuring sensor center axes;

[0089] β is the angle between the visual positioning module and the overhead wire.

[0090] π is the circular constant.

[0091] Through this positioning method, the position of the overhead wire can be accurately measured under the action of the CCD camera 1 and the laser measuring sensor 2, and after accurate positioning, other tools can be guided to work on the wire, such as stripping tools for stripping the wire, wire clamp installation tools for installing wire clamps, etc., so as to avoid the situation that the robot cannot normally use the working tool due to the inaccurate positioning of the position of the wire, and also prevent the working tool from damaging the wire due to inaccurate positioning.

[0092] It is obvious to those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit and essential characteristics of the present application. Therefore, the embodiments should be regarded as exemplary and non-limiting, and the scope of the present application is defined by the appended claims rather than the above description, and it is intended to encompass all changes falling within the meaning and scope of the equivalent elements of the claims. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0093] In addition, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can be properly combined to form other embodiments that those skilled in the art can understand.

Claims

1. A positioning method based on an overhead wire spatial vision positioning module, characterized in that, The overhead wire spatial visual positioning module comprises a CCD camera, a plurality of laser measuring sensors respectively located on both sides of the CCD camera, and a control unit; The control unit comprises a controller and a control platform in wireless communication connection with the controller, and the control platform is provided with a plurality of motors capable of driving the visual positioning module to rotate or move in the horizontal direction respectively; Further comprising the following steps: Step one: the visual positioning module collects two-dimensional scene image data and spatial coordinate position information data at a preset spatial position through the CCD camera; Step two: the collected two-dimensional scene image data is processed and calculated to obtain two-dimensional angle deflection information of the overhead wire in the two-dimensional scene image data; Step three: the controller drives the motor according to the two-dimensional angle deflection information of the overhead wire obtained in step two, so that the visual positioning module rotates to make the horizontal direction of the visual positioning module keep parallel to the overhead wire; Step four: the two-dimensional scene image data and spatial coordinate information data are collected again, and the fitting straight line is obtained according to the image processing mode in step two, and the central coordinate position of the image data is calculated, the longitudinal pixel deviation between the fitting straight line and the center of the image data is calculated through the pixel difference between the longitudinal coordinates of the fitting straight line and the center of the image data, the motor pulse step number is converted according to the image pixel and motor pulse proportion relationship, and the controller drives the motor to make the visual positioning module move radially, so that the center position of the visual positioning module coincides with the axis of the overhead wire; Step five: the two laser measuring sensors on the visual positioning module measure the distance of the overhead wire, and the axial deflection angle of the overhead wire relative to the visual positioning module is calculated through the distance difference measured by any two laser measuring sensors, and the visual positioning module is driven to rotate by the corresponding deflection angle to make the visual positioning module parallel to the overhead wire in the side view direction.

2. The positioning method based on the overhead wire space visual positioning module according to claim 1, wherein, The image processing mode is: (1) the two-dimensional scene image collected by the CCD camera is processed in gray scale, and the formula used is: gray=0.39×R+0.5×G+0.11×B; (2) the edge detection processing is performed on the gray scale image to obtain the outline of the overhead wire in the image, and the Sobel edge detection operator is used: firstly, weighted average is performed, and then differential operation is performed, and the calculation method of the operator is as follows: ； ； the gradient size is calculated in combination with the horizontal and vertical gradient approximations of the pixels in the image: ； (3) the Hough transform is used for feature extraction of the overhead wire, the edge line of the overhead wire is extracted and fitted into a straight line, and the Hough transform polar coordinate operation is used: ； wherein denotes the polar radius; denotes the polar angle; (4) Obtain the end points P1 , P2 of the fitting straight line, and calculate the angle of the fitting straight line relative to the horizontal plane of the visual positioning module; the formula for calculating the angle is: 。 3. The positioning method according to claim 2, wherein The calculation formula of the motor pulse step number is: ； Wherein, Pl is the motor pulse number; is the longitudinal pixel deviation value of the fitting straight line and the center coordinate; is the proportional relationship between the image pixel and the motor pulse.

4. The positioning method based on the overhead wire space visual positioning module according to claim 2, wherein, The calculation method of the axial deflection angle of the overhead wire relative to the visual positioning module is: the axial deflection angle of the overhead wire relative to the visual positioning module is calculated by using the arctangent function through the distance difference between the center axes of the two laser measuring sensors and the distance between the visual positioning module and the overhead wire measured by the two laser measuring sensors, and the calculation formula is: ; wherein, D1 is the distance measured by the laser measurement sensor 1 from the visual positioning module to the overhead power line; the visual positioning module measures the distance from the overhead line for the laser measuring sensor No. 2; Distance between the center axes of the two laser measuring sensors; To find the visual positioning module and overhead wire angle distance; is the circumference of a circle of radius 1.

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