A real-time monitoring method for operating state of a box-type substation

Abstract

The application relates to the technical field of image processing, in particular to a real-time monitoring method for the operation state of a box-type substation. The method comprises the following steps: acquiring a monitoring image containing a pointer-type instrument in the box-type substation, and determining a circular window with the candidate center point of the monitoring image as the center; determining the connecting line of the target pixel point in the circular window to the candidate center point, and determining the probability value of the target pixel point belonging to the scale line according to the degree of the gradient direction of the target pixel point being perpendicular to the connecting line, so as to determine the evaluation value of the candidate center point; determining the target instrument region according to the candidate center point with the maximum evaluation value, and detecting the reading indicated by the pointer-type instrument from the target instrument region by using Hough line transformation. Through the above technical scheme, the automatic reading of the reading of the pointer-type instrument in the box-type substation can be realized, and the operation state monitoring of the box-type substation is facilitated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of image processing, and particularly relates to a real-time monitoring method for operation state of a box-type substation. BACKGROUND

[0002] The box-type substation is a power distribution device integrating high-voltage switchgear, transformers and low-voltage distribution equipment in a box, which can be applied to urban power supply, industrial and mining enterprises, new energy and temporary power supply scenarios. The box-type substation can convert high-voltage power into low-voltage power suitable for user use, thereby meeting the power demand of different equipment. The box-type substation can receive high-voltage power from the upstream power grid and distribute and control the power through internal high-voltage switchgear, thereby ensuring stable transmission of power to the downstream.

[0003] The box-type substation is usually provided with a voltmeter, an ammeter, a frequency meter and a temperature meter, etc. These pointer-type instruments can indicate the voltage, current, working frequency and temperature of the equipment in the box-type substation.

[0004] The pointer-type instrument adopts a mechanical structure and has low sensitivity to electromagnetic interference, so that the pointer-type instrument can maintain stable measurement performance in a complex electromagnetic environment. In addition, the structure of the pointer-type instrument is simple, and the number of components is less, so that the pointer-type instrument can exhibit high durability in long-term use and is convenient to maintain and calibrate.

[0005] Since the pointer-type instrument can effectively indicate the detected parameters in the box-type substation, in order to facilitate the monitoring of the parameters detected by the pointer-type instrument, for example, in order to facilitate the monitoring of the working current and working voltage of the components in the box-type substation, the pointer-type instrument in the box-type substation can be monitored. SUMMARY

[0006] In order to monitor the pointer-type instrument in the box-type substation, the present application provides a real-time monitoring method for operation state of a box-type substation, comprising: acquiring a monitoring image containing a pointer-type instrument in the box-type substation, taking any one pixel point in the monitoring image as a candidate center point, and determining a circular window with the candidate center point as the center; for a target pixel point in the circular window except the candidate center point, determining a connecting line from the target pixel point to the candidate center point, and determining a feature value of the target pixel point according to the degree of perpendicularity between the gradient direction of the target pixel point and the connecting line; determining a probability value of the target pixel point belonging to a scale line according to the product of the gradient amplitude of the target pixel point and the feature value; taking the sum of the probability values of all target pixel points in the circular window as the evaluation value of the candidate center point; taking the candidate center point with the maximum evaluation value as a target center point, determining a target instrument region with the target center point as the center, and detecting a reading indicated by the pointer-type instrument from the target instrument region by using Hough line transformation.

[0007] In this way, the automatic reading of the reading of the pointer type instrument in the box-type substation can be realized.

[0008] Optionally, the probability value that the target pixel point belongs to the scale line is determined by the following manner: , wherein C is the probability value that the target pixel point belongs to the scale line, max is a maximum value function, cos is a cosine function, is an included angle between the gradient direction of the target pixel point and the connecting line, sin is a sine function, M is the gradient amplitude of the target pixel point, exp is an exponential function with a natural constant as a base number, is a distance from the target pixel point to the candidate center point, R is a radius of the circular window, is a standard deviation of the different target pixel points.

[0009] Optionally, the target instrument region with the target center point as the center is determined by: respectively determining circular lines with the target center point as the center according to different candidate radii, and determining a matching degree value of the candidate radii according to the periodicity of the pixel values of the pixel points on the circular lines; the matching degree value is used to represent the degree of periodicity of the pixel values of the pixel points on the circular lines; the candidate radius with the maximum matching degree value is taken as the target radius, and the circular region with the target center point as the center and the target radius as the radius is taken as the target instrument region.

[0010] In this way, the matching degree value corresponding to the candidate radius can be determined by combining the periodicity of the scale line in the instrument region, so that the target instrument region that is more matched with the actual radius of the instrument region is obtained.

[0011] Optionally, the matching degree value of the candidate radius is determined by the following manner: taking the angle of the pixel point on the circular line corresponding to the candidate radius relative to the target center point as the independent variable, and taking the pixel value of the pixel point on the circular line corresponding to the candidate radius as the dependent variable, to obtain a one-dimensional angle signal corresponding to the candidate radius; performing Fourier transform on the angle signal to obtain a frequency spectrum, determining the maximum amplitude of the frequency spectrum in a frequency band greater than a preset frequency, and determining the total energy of the frequency spectrum in all frequency bands, and taking the ratio of the maximum amplitude to the total energy as the matching degree value.

[0012] In this way, the pixel value of the pixel point on the circular line is converted into an angle signal according to the angle, and the periodicity of the pixel value of the pixel point on the circular line can be analyzed after the Fourier transform.

[0013] ​Optionally, the matching degree value of the candidate radius is determined by: obtaining a pixel value sequence according to pixel values of the pixel points on the circular line corresponding to the candidate radius, determining interval information of angles corresponding to the pixel points in the same gray range in the pixel value sequence, and determining the matching degree value according to consistency of the different interval information; the matching degree value is positively correlated with the consistency of the different interval information.

[0014] In this way, the periodicity of the pixel values of the pixel points on the circular line can be described according to the interval information of the pixel values of the pixel points on the circular line.

[0015] Optionally, in the case that the number of the candidate radius with the maximum matching degree value is multiple, the method further comprises: determining the candidate radius with the maximum radius value as the target radius from the multiple candidate radii with the maximum matching degree value.

[0016] Optionally, the different candidate radii are determined by: obtaining an initial radius value corresponding to the pointer instrument, and determining a radius range according to the initial radius value, and taking the radii within the radius range as the different candidate radii; the radius range is centered on the initial radius value.

[0017] Optionally, the reading indicated by the pointer instrument is determined from the target instrument region by using the Hough line transformation, comprising: determining the indication direction of the pointer from the target instrument region by using the Hough line transformation, and determining the reading indicated by the pointer instrument according to the indication direction and a preset corresponding relationship; the preset corresponding relationship is used to represent the corresponding relationship between different indication directions and different readings.

[0018] Optionally, the box-type substation is provided with a lighting device, and the lighting device is used to provide illumination for the pointer instrument, and the method further comprises: obtaining the ambient light intensity of the pointer instrument, and controlling the light intensity of the lighting device according to the ambient light intensity.

[0019] In this way, the adaptive illumination of the pointer instrument can be realized according to the ambient light intensity.

[0020] Optionally, the method further comprises: obtaining target monitoring information of the box-type substation, and sending the target monitoring information to a server, so that the server monitors the running state of the box-type substation according to the target monitoring information; the target monitoring information comprises temperature information, voltage information, partial discharge information and vibration information.

[0021] The technical scheme provided by the embodiment of the application can have the following beneficial effects: a monitoring image containing a pointer instrument in a box-type substation is acquired, and a circular window with a candidate center point in the monitoring image as a center is determined; the scale lines in the pointer instrument usually point to the same center point, the degree of perpendicularity between the gradient direction of a pixel point in the circular window and the included angle between the pixel point and the line connecting the pixel point to the candidate center point is determined, the sum of the probability values of all target pixel points in the circular window is taken as an evaluation value of the candidate center point, the evaluation value can reflect the number of scale lines included in the circular region, the identification of the target instrument region from the entire monitoring image is facilitated, the Hough line transformation is used to detect the reading indicated by the pointer instrument from the target instrument region, the automatic monitoring of the reading of the pointer instrument can be realized, and the internal circuit of the box-type substation does not need to be modified, so that the monitoring cost of the pointer instrument is lower.

[0022] It should be understood that the foregoing general description and the following detailed description are only exemplary and explanatory and are not restrictive of the application. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a flowchart of a real-time monitoring method for a box-type substation operating state according to an exemplary embodiment;

[0024] Figure 2 is a schematic diagram of an edge image of an instrument region in an embodiment of the application;

[0025] Figure 3 is a variation schematic diagram of matching degree values of different candidate radii in an embodiment of the application;

[0026] Figure 4 is a schematic diagram of an identification result of an instrument region in an embodiment of the application. DETAILED DESCRIPTION

[0027] First, the application scenario of the embodiment of the application is briefly introduced. In the application scenario of the application, the working current, working voltage, and temperature information of the equipment in the box-type substation can be monitored through the pointer instrument. Therefore, in order to facilitate the monitoring of the information detected by the pointer instrument, the pointer instrument can be monitored to realize the automatic reading of the information monitored by the pointer instrument.

[0028] To solve the above technical problems, the embodiment of the application provides a real-time monitoring method for a box-type substation operating state, Figure 1 is a flowchart of a real-time monitoring method for a box-type substation operating state according to an exemplary embodiment, as shown in Figure 1 , the method comprises the following steps.

[0029] In step S101, a monitoring image containing a pointer instrument in the box-type substation is acquired, any one pixel point in the monitoring image is taken as a candidate center point, and a circular window with the candidate center point as the center is determined.

[0030] The monitoring image can be acquired by a camera arranged inside the box-type substation. The camera can continuously shoot the instruments inside the box-type substation and periodically transmit images to the processing unit. After the monitoring image is acquired, the system can perform pre-processing on the image, such as grayscale or denoising, etc., so as to facilitate subsequent identification of the pointer instrument.

[0031] The pointer instrument contained in the monitoring image can be any one of a pointer temperature instrument, a pointer voltage instrument, and a pointer current instrument, etc.

[0032] When identifying the specific position of the pointer instrument in the monitoring image, the position of the center of the instrument panel can be determined. In this embodiment, any one pixel point in the monitoring image can be taken as a candidate center point by traversing each pixel point in the monitoring image. A circular window is determined with the candidate center point as the center and according to a preset radius.

[0033] The preset radius can be greater than or equal to the radius of the instrument region in the pointer instrument, and can be determined according to the size range of the instrument region in the pointer instrument.

[0034] In step S102, for a target pixel point in the circular window except the candidate center point, a connecting line of the target pixel point to the candidate center point is determined, and a feature value of the target pixel point is determined according to a degree of perpendicularity between a gradient direction of the target pixel point and the connecting line.

[0035] The target pixel point can be any one pixel point in the determined circular window except the candidate center point. Different candidate center points in the monitoring image correspond to different circular regions, so that different circular regions can correspond to different pixel points, respectively.

[0036] In the circular window determined for the candidate center point, the gradient information of each target pixel point can be determined, including the gradient amplitude and the gradient direction. The gradient amplitude can reflect the intensity of the change in the gray value, and the gradient direction can reflect the direction in which the change in the gray value is fastest.

[0037] The gradient amplitude of the pixel value of the target pixel point in the circular window is large, which means that the target pixel point is more likely to be located at the edge of the image, such as the edge of the scale or the pointer in the instrument region. The gradient direction points to the direction in which the pixel value changes fastest.

[0038] In addition to the image region where the envelope pointer instrument is located, the obtained monitoring image usually also includes other regions in addition to the instrument region, and the position of the pointer instrument in the monitoring image can not be fixed, so that the reading indicated by the pointer instrument cannot be directly recognized from the monitoring image.

[0039] The pointer instrument uses the cooperation of the pointer and the scale line in the instrument region to realize the indication of the detected parameter; the scale line of the instrument region is distributed radially around the center of the pointer, and the pointer can hover on the corresponding scale line through rotation, so that the straight line where the scale line of the pointer instrument is located intersects at the center position of the instrument region.

[0040] The embodiments of the present application mainly monitor the pointer instrument with a circular instrument region, and in the embodiments of the present application, the center of the instrument region is the same position as the center of rotation of the pointer.

[0041] The color of the scale line in the instrument region of the pointer instrument is usually black, and the color of the background of the instrument region where the scale line is located is usually white which is obviously different from black, so the gradient direction of the pixel point located in the scale line is perpendicular to the straight line where the scale line is located.

[0042] Since the straight line where the scale line of the pointer instrument is located intersects at the center position of the instrument region, and the gradient direction of the scale line is perpendicular to the straight line where the scale line is located, if the candidate pixel point is the center pixel point of the instrument region, the gradient direction of the pixel point located in the scale line can exhibit the feature that the line to the candidate center pixel point is perpendicular.

[0043] If the candidate center point is not the center of the instrument region of the pointer instrument, the gradient direction of the pixel point located in the scale line in the instrument region cannot be perpendicular to the line to the candidate center pixel point.

[0044] Alternatively, if the pixel point in the circular region of the candidate center point is not located on the scale line, for example, the target pixel point is a pixel point of other equipment in the box-type substation, the target pixel point in the circular region also cannot exhibit the feature that the gradient direction is perpendicular to the line to the candidate center point.

[0045] Using the feature between the scale line in the pointer instrument and the center of the instrument region, the feature value of the target pixel point can be determined according to the degree of perpendicularity between the gradient direction of the target pixel point and the line; the feature value of the target pixel point can represent the probability that the pixel point is located on the scale line of the instrument region of the pointer instrument, so as to realize the automatic positioning of the instrument region from the entire monitoring image by combining the feature value of the target pixel point.

[0046] In step S103, a probability value of the target pixel point belonging to the scale line is determined according to the product of the gradient amplitude value of the target pixel point and the characteristic value, and a sum of probability values of all target pixel points in the circular window is taken as the evaluation value of the candidate center point.

[0047] Compared with the white background pixel points other than the scale line that can exist in the circular region, the pixel points located on the scale line are located at the edge, so that the gradient amplitude value of the pixel points located on the scale line is larger; compared with the edge pixel points other than the scale line that can exist in the circular region, the pixel points located on the scale line have the characteristic that the gradient direction is perpendicular to the connecting line to the center of the instrument region, and therefore, according to the product of the gradient amplitude value of the target pixel point and the characteristic value, the probability value of the target pixel point belonging to the scale line can be determined more accurately, and the interference of the white background pixel points other than the scale line and the edge pixel points other than the scale line is avoided.

[0048] In one embodiment, the probability value of the target pixel point belonging to the scale line is determined by the following manner: wherein C is the probability value of the target pixel point belonging to the scale line, max is a maximum value function, cos is a cosine function, is an included angle between the gradient direction of the target pixel point and the connecting line, sin is a sine function, M is the gradient amplitude value of the target pixel point, exp is an exponential function with a natural constant as the base number, is a distance from the target pixel point to the candidate center point, R is a radius of the circular window, is a standard deviation of the of different target pixel points.

[0049] In the circular region corresponding to the candidate center point, if the candidate center point is located at the center point of the instrument region, the circular region can include a larger number of scale lines, and the pixel points located on the scale line can more present the characteristic that the gradient direction is perpendicular to the connecting line to the candidate center point, so that a larger number of pixel points with a higher probability value belonging to the scale line can be contained in the circular region.

[0050] For all target pixel points in the circular region, the gradient amplitude value of the pixel points located on the scale line is larger than that of the white background part; compared with other edge pixel points that can exist in the circular region, the pixel points of the scale line have a larger degree of perpendicularity between the gradient direction and the connecting line to the center of the instrument region, and therefore, the pixel points belonging to the scale line can be assigned a higher probability value.

[0051] The maximum value function existing in the middle can assign a higher value to the pixel point whose angle between the gradient direction of the target pixel point and the line connecting the target pixel point and the candidate center point is closer to 90 degrees, and can also obtain a larger value when the angle between the gradient direction of the target pixel point and the line connecting the target pixel point and the candidate center point has a certain deviation from 90 degrees, so that the obtained circular region contains more pixel points on the scale line.

[0052] When the distance between the target pixel point in the circular region and the candidate center pixel point is more consistent with the radius of the circular region, the target pixel point is more likely to be the pixel point at the end of the scale line in the instrument region, so that a larger value is obtained, and the existence of the standard deviation can realize the dimensionless processing of the distance variable.

[0053] In this way, in combination with the feature that the scale line in the instrument region radiates along the same position point, a better probability value can be determined for the pixel point that is more consistent with the characteristics of the scale line, so that the device can facilitate the automatic positioning of the instrument region in the obtained monitoring image.

[0054] In step S104, the candidate center point with the maximum evaluation value is taken as the target center point, a target instrument region with the target center point as the center is determined, and the Hough line transformation is used to detect the reading indicated by the pointer instrument from the target instrument region.

[0055] The evaluation value of the circular window corresponding to the candidate center point is equal to the sum of the probability values of all target pixel points in the circular window, and the probability value of the target pixel point can represent the probability that the target pixel point is located on the scale line of the instrument region, therefore, the circular region with a larger evaluation value includes more scale lines, and the circular window in which the candidate center point with the maximum evaluation value is located is the image region that is the most matched center point of the instrument region among all the circular windows.

[0056] Taking the candidate center point with the maximum evaluation value as the target center point realizes the positioning of the center point of the instrument region in the monitoring image, and through cooperation with the radius of the instrument region, the electronic device can automatically locate the image region in which the instrument region is located from the monitoring image.

[0057] In one embodiment, determining the target instrument region with the target center point as the center includes: respectively determining circular lines with the target center point as the center according to different candidate radii, and determining a matching degree value of the candidate radius according to the periodic feature of the pixel values of the pixel points on the circular line; the matching degree value is used to represent the degree of periodicity of the pixel values of the pixel points on the circular line; taking the candidate radius with the maximum matching degree value as the target radius, and taking the circular region with the target center point as the center and the target radius as the radius as the target instrument region.

[0058] In a case where the position of the center point of the instrument region in the monitoring image has been determined, in order to exclude the interference of other regions in the circular region with the target center point as the center, for example, the radius of the determined circular region can be greater than or equal to the actual radius of the instrument region in the monitoring image, so that the circular region with the target center point as the center can also include the external contours of the pointer instrument, which can be incorrectly identified as pointers in subsequent identification of the pointers, causing errors in reading. Therefore, a more accurate target instrument region can be determined based on the circular region with the target center point as the center.

[0059] For the scale lines in the instrument region of the pointer instrument, adjacent scale lines are usually arranged at the same interval in a clockwise or counterclockwise direction, and the colors of the scale lines are usually all black or all dark gray, so that the pixel values of the pixel points on the same circular line will periodically change in the clockwise or counterclockwise direction.

[0060] For the external contours or other background pixel points of the pointer instrument that can exist in the circular region, these pixel points are usually not arranged at the same interval in the clockwise or counterclockwise direction. Therefore, by using the characteristic that the scale lines are arranged at the same interval in the clockwise or counterclockwise direction, a target instrument region that is more matched to the actual instrument region can be determined.

[0061] The circular line corresponding to the candidate radius is a circular closed line with the target center point as the center and the radius equal to the candidate radius. The matching degree value of the candidate radius can be determined according to the periodicity of the pixel values of the pixel points on the circular line. The higher the periodicity of the pixel values of the pixel points on the circular line, the higher the degree that the candidate radius is the actual radius of the instrument region. Therefore, the candidate radius with the highest matching degree value among the multiple candidate radii can be determined as the actual radius of the instrument region, so as to obtain the target instrument region, which is a region with a lower proportion of other regions than the instrument region.

[0062] In this way, the obtained target instrument region is obtained according to the arrangement of the scale lines at the same interval in the clockwise or counterclockwise direction, avoiding the influence of other regions than the actual instrument region in the image. In subsequent identification of the pointers using the target instrument region, the influence of other regions than the actual instrument region on the identification result of the pointers can be avoided.

[0063] The multiple candidate radii can be determined according to the range of radii that the actual radius of the instrument region of the pointer instrument can usually reach in the image coordinate system. For example, the multiple candidate radii can be selected from the range of 85% to 115% of the actual radius of the instrument region.

[0064] In one embodiment, the matching degree value of the candidate radius is determined by taking the angle of the pixel point on the circular line corresponding to the candidate radius relative to the target center point as the independent variable and taking the pixel value of the pixel point on the circular line corresponding to the candidate radius as the dependent variable to obtain a one-dimensional angle signal corresponding to the candidate radius; performing Fourier transform on the angle signal to obtain a frequency spectrum, determining the maximum amplitude of the frequency spectrum in a frequency band greater than a preset frequency, and determining the total energy of the frequency spectrum in all frequency bands, and taking the ratio of the maximum amplitude to the total energy as the matching degree value.

[0065] The pixel points on the circular line corresponding to the candidate radius can be sampled at equal angles from the target center point as the center of the circle to obtain the pixel values of the pixel points selected in clockwise or counterclockwise order on the circular line corresponding to the candidate radius; or all pixel points on the circular line corresponding to the candidate radius can be selected.

[0066] For all the selected pixel points on the circular line corresponding to the candidate radius, since the scale lines are arranged at equal intervals in clockwise or counterclockwise direction, the angle relative to the target center point can be taken as the independent variable and the pixel value or gray value of the pixel point can be taken as the dependent variable to obtain a one-dimensional angle signal corresponding to the candidate radius; wherein the angle signal includes the relationship between the pixel value or gray value of the selected pixel point and the angle.

[0067] Performing Fourier transform on the angle signal to obtain a frequency spectrum can facilitate the evaluation of the periodicity of the angle signal in the obtained Fourier frequency spectrum, thereby realizing the evaluation of the periodicity of the pixel value of the pixel point on the circular line.

[0068] The Fourier transform of the angle signal can be implemented, for example, by one-dimensional discrete Fourier transform, and the frequency spectrum obtained by the Fourier transform can be well used to evaluate the periodicity of the signal, therefore, the Fourier transform is selected by the embodiments of the application to analyze the angle signal.

[0069] The preset frequency is used to filter out the low-frequency signal of random noise that may exist in the frequency spectrum, and can be set according to the actual situation of the frequency spectrum corresponding to the scale line of the instrument region.

[0070] When the pixel value of the pixel point on the circular line changes periodically, for example, there are 40 scale lines arranged at equal intervals on the circular line, and the pixel values of different scale lines are usually the same, therefore, there are 40 periodically appearing pixel values in the circular line, so that there is a high peak at the frequency corresponding to 40 in the obtained frequency spectrum, and the energy of the frequency spectrum is mainly concentrated in the frequency corresponding to the periodic change.

[0071] When the circular line does not correspond to the scale line of the instrument region, for example, the circular line includes a background region that does not present periodic changes and edges, the pixel values of the pixel points on the circular line cannot present periodic changes, so that the frequency spectrum can have peaks at different frequencies, and the energy distribution of the frequency spectrum is relatively dispersed.

[0072] When the circular line of the candidate radius is located on the circular line where the scale line of the instrument region is located, the frequency spectrum obtained by performing Fourier transform on the angle signal is concentrated at a single frequency corresponding to the periodic changes, so that the maximum amplitude in the frequency spectrum is closer to the energy value of the entire frequency spectrum; the total energy of the frequency spectrum in all frequency bands can be equal to the integral or cumulative sum of the amplitudes of all frequencies.

[0073] In this way, since the frequency spectrum of the angle signal of the circular line with periodic pixel values is concentrated at a single frequency, the ratio of the maximum amplitude to the total energy in the frequency spectrum obtained by the circular line actually corresponding to the scale line is larger, so that a larger matching degree value can be determined for the circular line including pixel points with more periodic pixel values.

[0074] In an embodiment, the matching degree value of the candidate radius is determined by the following manner: obtaining a pixel value sequence according to the pixel values of the pixel points on the circular line corresponding to the candidate radius, determining interval information of angles corresponding to the pixel points in the same gray range in the pixel value sequence, and determining the matching degree value according to the consistency degree of different interval information; the matching degree value is positively correlated with the consistency degree of different interval information.

[0075] For the scale lines arranged at equal intervals in the clockwise or counterclockwise direction, the pixel values of the pixel points on the circular line including the position points in the scale line are also arranged at equal intervals, and the gray values of different scale lines are usually located in the same gray range, so that the intervals of angles corresponding to the pixel points in the same gray range can be determined.

[0076] The consistency degree of different interval information indicates that the more periodic the changes of the pixel values of different pixel points are, the higher the matching degree value obtained is; on the contrary, the lower the consistency degree of different interval information is, the more random the changes of the pixel values of different pixel points are, and the lower the matching degree value obtained is; the matching degree value can be equal to the inverse of the natural exponential function of the variance of different interval information, for example.

[0077] In an embodiment, when the number of candidate radii with the maximum matching degree value is multiple, the candidate radius with the maximum radius value can be determined as the target radius from the multiple candidate radii with the maximum matching degree value.

[0078] In the instrument region of the pointer instrument, the scale line usually has a certain length, so that the circular lines within the scale line range certainly all exhibit higher periodicity, and the multiple candidate radii that match the maximum degree value can correspond to different candidate radii respectively corresponding to the length of the scale line.

[0079] Taking the candidate radius with the maximum radius value as the target radius, the radius of the left outer side of the scale line relative to the target center point can be determined as the target radius, which can make the circular region determined by the target radius include more complete information of the pointer.

[0080] In an embodiment, the different candidate radii are determined by: obtaining an initial radius value corresponding to the pointer instrument, and determining a radius range according to the initial radius value, and taking the radii within the radius range as different candidate radii respectively; the radius range is centered on the initial radius value.

[0081] The actual radius of the instrument region of the pointer instrument in the space world coordinate system can be taken as the initial radius, and when the image acquisition device performs image acquisition on the range where the pointer instrument is located, the radius of the instrument region in the image coordinate system can have certain changes around the initial radius, so the initial radius can be taken as the center to determine the radius range.

[0082] The multiple candidate radii can be obtained by selecting the candidate radii at equal intervals from the radius range, and by setting the multiple candidate radii, the selection of the instrument region can adapt to the changes of the instrument region in the image coordinate system caused by different acquisition distances of the image acquisition device, and the adaptability of automatic monitoring of the reading of the pointer instrument is improved.

[0083] In an embodiment, the reading indicated by the pointer instrument is determined from the target instrument region by using Hough line transformation, including: determining the indication direction of the pointer from the target instrument region by using Hough line transformation, and determining the reading indicated by the pointer instrument according to the indication direction and a preset corresponding relationship; the preset corresponding relationship is used to represent the corresponding relationship between different indication directions and different readings.

[0084] The straight line feature of the pointer in the instrument region is most obvious, and the straight line length of the pointer in the target region is the largest, so the detection of the straight line in the target instrument region can be realized by using Hough line transformation.

[0085] Since the determined target instrument region has realized the identification of the instrument region from the complete monitoring image, the target instrument region can be sequentially subjected to grayscale processing, edge detection and binarization to obtain a binary image, realize the extraction of the pointer and the scale line in the instrument region, and then be subjected to Hough transformation processing.

[0086] The direction indicated by the pointer in the target region can be determined by extracting a straight line from the binary image through the Hough line transformation, which will not be described herein. The Hough line transformation converts a straight line in the image space into a point in the parameter space, and determines the straight line in the image by detecting the peak value in the parameter space.

[0087] Different directions in the pointer instrument usually correspond to different readings of the pointer instrument respectively. The correspondence between the different directions and the different readings can be calibrated in advance to obtain a preset correspondence, and the preset correspondence is used to represent the correspondence between the different indication directions and the different readings.

[0088] According to the direction indicated by the pointer obtained by the Hough transformation and the preset correspondence, the reading indicated by the pointer instrument can be determined, and the automatic reading of the reading of the pointer instrument is realized.

[0089] Figure 2 is a schematic diagram of an edge image of the instrument region in the embodiment of the present application, as Figure 2 The scale lines in the instrument region are radially arranged along the center point of the instrument region, and the adjacent scale lines have consistent intervals in the clockwise direction.

[0090] The target center point and the target radius in the embodiment of the present application can be determined by using the determination process of the target center point and the target radius. Figure 2 The target radius of the pointer instrument corresponding to Figure 3 is a schematic diagram of the change of the matching degree value of different candidate radii in the embodiment of the present application, as Figure 3 The matching degree value obtained at the target radius in different candidate radii is the highest.

[0091] The target center point and the target radius determined can be used to automatically identify the reading from the instrument region, Figure 4 is a schematic diagram of the identification result of the instrument region in the embodiment of the present application, as Figure 4 The identification result of the pointer instrument in the embodiment of the present application is 0.6Mpa.

[0092] In one embodiment, the box-type substation is provided with a lighting device for providing illumination for the pointer instrument, and the environmental illumination intensity of the pointer instrument can be obtained, and the illumination intensity of the lighting device is controlled according to the environmental illumination intensity.

[0093] The lighting device can be arranged on the side or top of the pointer instrument of the box-type substation, so that the light output by the photo device can irradiate the surface of the pointer instrument; through the illumination of the photo device on the pointer instrument, the features of the pointer instrument in the monitoring picture collected by the image collection device can be better presented, thereby facilitating the automatic reading of the reading indicated by the pointer instrument.

[0094] According to the acquired ambient light intensity, when the ambient light intensity is lower, in order to ensure the automatic recognition of the reading of the pointer instrument, the lighting device can be controlled to illuminate the pointer instrument with higher light intensity.

[0095] When the ambient light intensity is higher, the reading of the pointer instrument can be clearly presented through lower light intensity, and the lighting device can be controlled to illuminate the pointer instrument with lower light intensity.

[0096] In an embodiment, target monitoring information of the box-type substation can also be acquired and sent to the server, so that the server can monitor the operation state of the box-type substation according to the target monitoring information; the target monitoring information includes temperature information, voltage information, partial discharge information and vibration information.

[0097] The operation state of the box-type substation directly affects the power supply reliability of the box-type substation, so it is necessary to monitor the operation state of the box-type substation; when the operation state of the box-type substation is abnormal, it may be abnormal in terms of temperature information, voltage information, partial discharge information and vibration information, so corresponding sensors can be arranged in the box-type substation to acquire the temperature information, voltage information, partial discharge information and vibration information of the box-type substation.

[0098] The target monitoring information is sent to the server, and the server can monitor the operation state of the box-type substation according to the acquired target monitoring information; for example, when it is determined that the acquired target monitoring information is abnormal, the user is prompted that the operation state of the box-type substation is abnormal.

[0099] Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. It is intended that the application be limited only by the claims, in whatever form they are expressed. It is intended that the specification and examples be considered exemplary only, with the true scope of the application being indicated only by the following claims.

[0100] It should be understood that the application is not limited to the precise construction that has been described above and illustrated in the accompanying drawings, and that various modifications and changes can be made by those skilled in the art without departing from the scope of the application.

Claims

1. A real-time monitoring method for operating state of a box-type substation, characterized by, The method comprises the following steps: acquiring a monitoring image containing a pointer instrument in a box-type substation, taking any one pixel point in the monitoring image as a candidate center point, and determining a circular window with the candidate center point as the center; for a target pixel point in the circular window except the candidate center point, determining a connecting line from the target pixel point to the candidate center point, and determining a feature value of the target pixel point according to a degree of perpendicularity between a gradient direction of the target pixel point and the connecting line; determining a probability value of the target pixel point belonging to a scale line according to a product of a gradient amplitude of the target pixel point and the feature value, and taking a sum of probability values of all target pixel points in the circular window as an evaluation value of the candidate center point; taking the candidate center point with the maximum evaluation value as a target center point, determining a target instrument region with the target center point as the center, and detecting a reading indicated by the pointer instrument from the target instrument region by using a Hough line transformation; determining the target instrument region with the target center point as the center comprises: determining circular lines with the target center point as the center respectively according to different candidate radii, and determining a matching degree value of the candidate radius according to a periodic characteristic of pixel values of pixel points on the circular line; the matching degree value is used to represent a degree of periodicity of the pixel values of the pixel points on the circular line; taking the candidate radius with the maximum matching degree value as a target radius, and taking a circular region with the target center point as the center and the target radius as the radius as the target instrument region.

2. The real-time monitoring method for operating state of a box-type substation according to claim 1, characterized by, the probability value of the target pixel point belonging to the scale line is determined in the following manner: Where C is the probability value of the target pixel belonging to the tick mark, max is the maximum value function, and cos is the cosine function. Let be the angle between the gradient direction of the target pixel and the connecting line, sin be the sine function, M be the gradient magnitude of the target pixel, and exp be the exponential function with the natural constant as the base. R is the distance from the target pixel to the candidate center point, and R is the radius of the circular window. For different target pixels The standard deviation.

3. The real-time monitoring method for operating state of a box-type substation according to claim 1, characterized by, the matching degree value of the candidate radius is determined in the following manner: taking an angle of a pixel point on a circular line corresponding to the candidate radius relative to the target center point as an independent variable, and taking a pixel value of the pixel point on the circular line corresponding to the candidate radius as a dependent variable, to obtain a one-dimensional angle signal corresponding to the candidate radius; performing Fourier transformation on the angle signal to obtain a frequency spectrum, determining a maximum amplitude of the frequency spectrum in a frequency band greater than a preset frequency, and determining a total energy of the frequency spectrum in all frequency bands, and taking a ratio of the maximum amplitude to the total energy as the matching degree value.

4. The real-time monitoring method for operating state of a box-type substation according to claim 1, characterized by, the matching degree value of the candidate radius is determined in the following manner: obtaining a pixel value sequence from pixel values of pixel points on a circular line corresponding to the candidate radius, determining interval information of angles corresponding to pixel points in the same gray range in the pixel value sequence, and determining the matching degree value according to a consistency degree of different interval information; the matching degree value is positively correlated with the consistency degree of the different interval information.

5. The method of claim 1, wherein the method is characterized by, in the case that the number of candidate radii with the maximum matching degree value is multiple, the method further comprises: determining a candidate radius with the maximum radius value from the multiple candidate radii with the maximum matching degree value as the target radius.

6. The method of claim 1, wherein the method is a real-time monitoring method for operating conditions of a box-type transformer substation, characterized by, the different candidate radii are determined in the following manner: acquiring an initial radius value corresponding to the pointer instrument, and determining a radius range according to the initial radius value, and taking radii in the radius range as different candidate radii respectively; the radius range is centered on the initial radius value.

7. The method of claim 1, wherein the method is a real-time monitoring method for operating conditions of a box-type transformer substation, characterized by, the reading indicated by the pointer instrument is detected from the target instrument region by using the Hough line transformation, comprising: The indication direction of the pointer is determined from the target instrument area by using the Hough line transformation, and the reading indicated by the pointer instrument is determined according to the indication direction and a preset corresponding relationship, wherein the preset corresponding relationship is used to represent the corresponding relationship between different indication directions and different readings.

8. The method of claim 1, wherein the method is a real-time monitoring method for operating conditions of a box-type transformer substation, characterized by, The box-type substation is provided with a lighting device for providing illumination for the pointer instrument, and the method further comprises: The ambient light intensity of the pointer instrument is acquired, and the illumination intensity of the lighting device is controlled according to the ambient light intensity.

9. The method of claim 1, wherein the method is a real-time monitoring method for operating conditions of a box-type transformer substation, characterized by, The method further comprises: Target monitoring information of the box-type substation is acquired, and the target monitoring information is sent to a server, so that the server monitors the operation state of the box-type substation according to the target monitoring information; the target monitoring information comprises temperature information, voltage information, partial discharge information and vibration information.

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