Method and Device for Measuring Circuit Breaker Opening and Closing Speed ​​Based on Linear Scan Camera

Abstract

This invention discloses a method and apparatus for measuring the opening and closing speed of a circuit breaker based on a linear array camera. The method includes: acquiring multiple frames of images of a target moving with the circuit breaker during opening and closing using a linear array camera; for each frame of the target image, applying an image processing method based on edge detection to obtain the target's motion distance for each frame, and obtaining a curve showing the relationship between the target's motion distance and time; and calculating the circuit breaker's opening and closing speed characteristics based on the curve showing the relationship between the target's motion distance and time. This invention achieves indirect measurement of the circuit breaker's opening and closing speed, requires fewer pixels in the captured images, thus improving image processing efficiency; increases the number of one-dimensional pixels, thus improving measurement accuracy; and requires only a target on the rotating shaft, eliminating the need to change sensors for different objects, and is less affected by the environment in which the equipment is located, thus meeting the requirements for online measurement.

Description

Technical Field

[0001] This invention belongs to the field of power system monitoring technology, specifically relating to a method and device for measuring the opening and closing speed of circuit breakers based on a linear array camera. Background Technology

[0002] Circuit breakers are crucial electrical equipment in power plants, substations, and power transmission and transformation systems. Their opening and closing speeds directly affect their breaking and closing performance. Excessively high opening and closing speeds can subject the circuit breaker's moving mechanism to excessive mechanical stress and impact, causing mechanical damage to structural components, increasing mechanical wear, and reducing mechanical lifespan. Conversely, excessively low opening and closing speeds can affect the circuit breaker's arc-extinguishing effect, leading to prolonged arcing time, accelerating contact electrical wear, and thus reducing the circuit breaker's service life. Therefore, accurately measuring the opening and closing speed characteristics of circuit breakers is of great significance for their safe and reliable operation.

[0003] Typically, the moving and stationary contacts of a circuit breaker are encapsulated within an arc-extinguishing chamber, making it impossible to directly measure their motion characteristics. Therefore, the measurement of the opening and closing speeds of a circuit breaker usually employs indirect measurement methods. This involves using sensors to measure the speed of the operating mechanism connected to the moving contacts, thereby indirectly obtaining the circuit breaker's speed characteristics. Non-contact measurement methods, which use high-speed cameras to capture images and then process them to obtain the motion trajectory and speed of reference markers, are widely used due to their advantages, such as not requiring mechanical sensor fixtures on the moving mechanism, not needing voltage isolation, and meeting online measurement requirements. However, current high-speed cameras, specifically area scan cameras, acquire two-dimensional motion images of the moving mechanism. This process requires a large number of pixels, significant hardware resources, and is time-consuming.

[0004] To address the aforementioned issues, it is necessary to propose a reasonable and effective method and device for measuring the opening and closing speed of circuit breakers based on a linear array camera. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art, and provides a method and device for measuring the opening and closing speed of circuit breakers based on a linear array camera.

[0006] One aspect of the present invention provides a method for measuring the opening and closing speed of a circuit breaker based on a linear array camera, wherein a target is disposed on the rotating shaft of the circuit breaker, and the linear array camera corresponds to the target; the measurement method includes:

[0007] S1, acquire multiple frames of images of the target that move with the opening and closing of the circuit breaker using the line scan camera;

[0008] S2, For each frame of the target image, an image processing method based on edge detection is used to obtain the motion path of the target corresponding to each frame image, and then the relationship curve between the motion path of the target and time is obtained;

[0009] S3. Based on the curve showing the relationship between the target's movement stroke and time, the opening and closing speed characteristics of the circuit breaker are calculated.

[0010] Optionally, S2 specifically refers to: the target being provided with a calibration reference area and a calibration feature area that are set at relatively intervals;

[0011] For each frame of the target image, an edge detection-based image processing method is used to obtain the motion path of the target corresponding to each frame image, including:

[0012] An image processing method based on edge detection obtains the pixel abscissas of the calibration reference region and the calibration feature region in each frame of the image;

[0013] The motion path of the target in the corresponding frame image is calculated based on the pixel abscissas of the calibration reference region and the calibration feature region and the size of the target.

[0014] Optionally, the width of the calibration reference area along the length of the target is a fixed value;

[0015] The width of the calibration feature region at its first end along the length direction of the target increases or decreases linearly towards its second end.

[0016] Optionally, the motion path of the target in the corresponding frame image is calculated based on the pixel abscissas of the calibration reference region and the calibration feature region and the size of the target, specifically as follows:

[0017] The motion distance of the target in the corresponding frame image is calculated based on the pixel horizontal coordinates of the calibration reference region and the calibration feature region in each frame image, the width of the calibration reference region and the calibration feature region, and the length of the target.

[0018] Optionally, the grayscale transition regions are respectively located on both sides of the calibration reference region and the calibration feature region, and the grayscale value of the grayscale transition region is different from the grayscale value of the calibration reference region and the calibration feature region.

[0019] Optionally, the length of the target can be calculated according to the following formula:

[0020] L = θπr / 180;

[0021] Where L is the rotation distance of the rotating shaft surface, which is equal to the length of the target, θ is the angle through which the rotating shaft rotates, and r is the radius of the rotating shaft.

[0022] Optionally, the target has an upper boundary and a lower boundary, and the linear array camera corresponds to one of the upper and lower boundaries of the target.

[0023] Another aspect of the present invention provides a circuit breaker opening and closing speed measuring device based on a linear array camera, the measuring device comprising a linear array camera, a target, and a processing module;

[0024] The target is set on the rotating shaft of the circuit breaker, and the linear scan camera corresponds to the target.

[0025] The linear array camera is used to acquire multiple frames of images of the target as it moves with the opening and closing of the circuit breaker.

[0026] The processing module is electrically connected to the line scan camera and is used to apply an edge detection-based image processing method to each frame of the target image to obtain the motion path of the target corresponding to each frame image, and to obtain the relationship curve between the motion path of the target and time.

[0027] The processing module is also used to calculate the opening and closing speed characteristics of the circuit breaker based on the relationship curve between the movement stroke and time of the target.

[0028] Optionally, the target is provided with a calibration reference area and a calibration feature area that are set at relatively intervals; wherein,

[0029] The width of the calibration reference area along the length of the target is a fixed value;

[0030] The width of the calibration feature region at its first end along the length direction of the target increases or decreases linearly towards its second end.

[0031] Optionally, the target is further provided with grayscale transition regions, which are respectively located on both sides of the calibration reference region and the calibration feature region; the grayscale value of the grayscale transition region is different from the grayscale value of the calibration reference region and the calibration feature region.

[0032] This invention discloses a method and apparatus for measuring the opening and closing speed of a circuit breaker based on a linear array camera. A target is placed on the surface of the circuit breaker's rotating shaft. Multiple frames of images of the target moving with the circuit breaker's opening and closing are captured by the linear array camera. Image processing technology based on edge detection is used to obtain the target's movement distance in each frame. A curve showing the target's movement distance versus time is plotted, and the target's speed characteristic curve is calculated, thereby achieving indirect measurement of the circuit breaker's opening and closing speed. By utilizing a linear array camera and a target set on the rotating shaft, combined with an edge detection image processing method, indirect measurement of the circuit breaker's opening and closing speed is achieved. The number of pixels in the captured images is small, improving image processing efficiency; the increased one-dimensional pixel count improves measurement accuracy; this invention only requires setting a target on the rotating shaft, eliminating the need to change sensors for different objects, and is less affected by the environment in which the equipment is located, thus meeting online measurement requirements. Attached Figure Description

[0033] Figure 1 This is a flowchart illustrating a method for measuring the opening and closing speed of a circuit breaker based on a line array camera, according to an embodiment of the present invention.

[0034] Figure 2 This is a schematic diagram of the structure of a circuit breaker opening and closing speed measuring device based on a line array camera, according to another embodiment of the present invention.

[0035] Figure 3 This is a schematic diagram of the target structure in another embodiment of the present invention. Detailed Implementation

[0036] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] like Figure 1 As shown, one aspect of the present invention provides a method S100 for measuring the opening and closing speed of a circuit breaker based on a linear array camera, such as... Figure 2 As shown, a target 130 is installed on the rotating shaft 111 of the circuit breaker 110, and a linear array camera 120 corresponds to the target 130. The stationary contact 113 and the moving contact 114 are housed in the arc-extinguishing chamber 112 for closing and opening the circuit breaker 110. The arc-extinguishing chamber 112 encloses the stationary contact 113 and the moving contact 114. A connecting rod 115 is connected to one end of the moving contact 114, and the other end of the connecting rod 115, together with the crank arm 116 and the rotating shaft 111, forms an operating mechanism connected to the moving contact 114. The opening and closing speed of the circuit breaker 110 is indirectly measured by measuring the speed characteristics of the operating mechanism. Furthermore, the arc-extinguishing chamber 112, the stationary contact 113, the moving contact 114, and the operating mechanism together constitute the structure of the circuit breaker 110.

[0038] Measurement method S100 includes:

[0039] S110. Acquire multiple frames of images of the target as it moves with the opening and closing of the circuit breaker using the linear array camera.

[0040] Before acquiring multiple frames of images of the target moving with the circuit breaker through a line scan camera, the method further includes: first, acquiring the angle through which the rotating shaft 111 rotates during the opening and closing movement of the circuit breaker 110, based on the actual operating results of the circuit breaker 110.

[0041] Specifically, when the circuit breaker 110 is in the opening movement, under the action of the driving force, the rotating shaft 111 will rotate counterclockwise by θ°; when the circuit breaker 110 is in the closing movement, the rotating shaft 111 will rotate clockwise by θ°. θ is measured during the actual operation of the circuit breaker 110, and θ represents the angle through which the rotating shaft 111 rotates when the circuit breaker 110 is in the opening and closing movement.

[0042] Secondly, the length of target 130 was calculated.

[0043] Specifically, if the angle through which the rotating shaft 111 rotates during the opening and closing movement of the circuit breaker 110 is θ, and the radius of the rotating shaft 111 is r, then the rotation distance L of the surface of the rotating shaft 111 during the opening and closing movement of the circuit breaker 110 is:

[0044] L=θπr / 180; (1)

[0045] Where L is the rotation distance of the rotating shaft surface, which is equal to the length of the target. That is, the length of the target 130 is the same as the rotation distance of the rotating shaft 111 surface.

[0046] Calculate the rotation distance L on the surface of the rotating shaft 111 according to the above formula (1), and make a target 130 with a length of L and a width of W. The target 130 is set on the surface of the rotating shaft 111 by pasting or applying, and moves with the rotating shaft 111. After unfolding the target 130, its planar shape is as follows. Figure 2 The rectangle shown has a length of L and a width of W. When pasting, the long side of the target 130 should be placed along the rotation direction of the pivot 111. The width W is determined by the free space along the axis of the pivot 111.

[0047] A light source 140 is provided between the target 130 and the line scan camera 120. In this embodiment, the light source 140 is an LED light, which is used to supplement the image during shooting to avoid insufficient brightness when the exposure time of a single frame image is too short, which would cause difficulties for subsequent software recognition.

[0048] For example, the target 130 has an upper boundary and a lower boundary, and the line scan camera 120 corresponds to one of the upper boundary and the lower boundary of the target 130.

[0049] Specifically, when the circuit breaker 110 performs the opening movement, the linear array camera 120 is positioned directly opposite the lower boundary of the target 130 to ensure that the first frame image has a travel distance of 0 during the opening movement. During the opening movement, multiple frames of images of the target 130 are captured from the lower boundary to the upper boundary, i.e., the first frame image A, the nth frame image B, and the last frame image C are captured. The captured images are long and narrow strips, such as... Figure 3 As shown in the first frame image A of the circuit breaker tripping, the resolution is 4096*32, which is significantly lower than the 1280*800 resolution image captured by the area array high-speed camera, resulting in a substantial reduction in the total number of pixels. Simultaneously, the number of one-dimensional pixels increases, improving measurement accuracy.

[0050] When the circuit breaker 110 is closing, the line scan camera 120 is positioned directly above the upper boundary of the target 130. Multiple frames of images are captured from the upper boundary to the lower boundary of the target 130, namely, the first frame image of closing, the nth frame image of closing, and the last frame image of closing.

[0051] S120. For each frame of the target image, an image processing method based on edge detection is used to obtain the motion path of the target corresponding to each frame image, and the relationship curve between the motion path of the target and time is obtained.

[0052] For example, the target 130 is provided with a calibration reference region 130a and a calibration feature region 130b that are spaced apart from each other. The width of the calibration reference region 130a along the length of the target 130 is a fixed value. The width of the calibration feature region 130b along the length of the target 130 increases or decreases linearly from its first end to its second end; that is, the width of the calibration feature region 130b at its first end is not the same as the width at its second end. It can be that the width at the first end decreases linearly towards the second end, or it can be that the width at the first end increases linearly towards the second end.

[0053] Specifically, such as Figure 3 As shown, in this embodiment, the calibration reference area 130a is a rectangle of fixed width, with a width of Wa on the target 130, serving as a reference value during the movement of the target 130. The calibration feature area 130b is located to the right of the calibration reference area 130a, serving as a change value during the movement of the target 130, and the grayscale value of the calibration feature area 130b is consistent with the grayscale value of the calibration reference area 130a.

[0054] like Figure 3As shown, in this embodiment, the width of the calibration feature region 130b at its first end along the length direction of the target 130 increases linearly towards its second end. That is, the shape of the calibration feature region 130b is a right trapezoid. The width of the second end of the calibration feature region 130b is Wc, meaning the lower base of the calibration feature region 130b on the target 130 is Wc. The width of the first end of the calibration feature region 130b is Wb, meaning the upper base of the calibration feature region 130b on the target 130 is Wb. Referring to the fixed width Wa of the calibration reference region 130a, and combining the first end dimension Wb, the second end width dimension Wc of the calibration feature region 130b, and the length L of the target 130, the travel distance of the target 130 corresponding to a single frame image of the target 130 is obtained.

[0055] like Figure 3 The target 130 also includes grayscale transition regions 130c, which are respectively located on both sides of the calibration reference region 130a and the calibration feature region 130b. The grayscale value of the grayscale transition region 130c differs from that of the calibration reference region 130a and the calibration feature region 130b. That is, the grayscale values ​​of the calibration reference region 130a and the calibration feature region 130b can be greater than the grayscale value of the grayscale transition region 130c, and vice versa. In other words, there are no specific requirements for the grayscale values ​​of the calibration reference region 130a, the calibration feature region 130b, and the grayscale transition region 130c, as long as the absolute value of the difference in grayscale values ​​between the calibration reference region 130a and the grayscale transition region 130c is greater than a preset threshold. The grayscale transition region 130c is used to form a step grayscale gradient with the calibration reference region 130a and the calibration feature region 130b, thereby obtaining a clear edge contour and improving the accuracy of edge detection.

[0056] In step S110, the first frame image A and the last frame image C of the tripping operation are located at the lower and upper edges of the target calibration reference area 130a and the calibration feature area 130b, respectively. During the tripping movement, the target 130 rotates counterclockwise by θ°, and the line scan camera 120 captures the first frame image to the last frame image. The first frame image and the last frame image of the closing operation are located at the upper and lower edges of the target calibration reference area 130a and the calibration feature area 130b, respectively. During the closing movement, the target 130 rotates clockwise by θ°, and the line scan camera 120 captures the first frame image to the last frame image.

[0057] For example, the step of applying an edge-detection-based image processing method to each frame of the target image to obtain the motion path of the target corresponding to each frame image includes:

[0058] First, an image processing method based on edge detection is used to obtain the pixel abscissas of the calibration reference region and the calibration feature region in each frame of the image.

[0059] Specifically, in this embodiment, taking the tripping motion of the circuit breaker 110 as an example, after the linear scan camera 120 successively acquires the first frame image A, the nth frame (n=2,3,4,5…) image B, and the last frame image C of the target 130, it performs smoothing, filtering, noise reduction, edge enhancement, and other related processing on these images. Based on edge detection technology, it extracts the pixel abscissas of the four positions of the gray-level gradient step in each image. In this embodiment, these are the pixel abscissas corresponding to the left and right boundaries of the equal-width rectangle of the calibration reference area 130a, the right-angled side boundary of the right trapezoid of the calibration feature area 130b, and the hypotenuse boundary. That is to say, the four positions of the gray-level gradient step in each image are located in the boundary areas between the calibration reference area 130a, the calibration feature area 130b, and the gray-level jump area 130c. The four abscissas of the first frame image A are denoted as X. 00 X 01 X 02 and X 03 The four horizontal coordinates of the nth frame image B are denoted as X. (n-1)0 X (n-1)1 X (n-1)2 and X (n-1)3 .

[0060] During the closing movement of circuit breaker 110, images of the first, nth, and last frames of the closing circuit are captured, from the upper to the lower boundary of target 130. These images undergo smoothing, filtering, denoising, and edge enhancement processes. Based on edge detection technology, the pixel horizontal coordinates of the four positions of the grayscale gradient step in each image are extracted. The specific process for obtaining the pixel horizontal coordinates is the same as that described for the opening movement of circuit breaker 110.

[0061] Secondly, based on the pixel horizontal coordinates of the four positions of the gray-level gradient step in each image, and referring to the fixed width Wa of the calibration reference area 130a, combined with the first end size Wb, the second end width size Wc of the calibration feature area 130b, and the length L of the target 130, the motion stroke of the target in the corresponding frame image is calculated.

[0062] Specifically, in this embodiment, the shape of the calibration reference area 130a is a fixed-width rectangle, and the shape of the calibration feature area 130b is a right trapezoid. Taking the circuit breaker 110 tripping motion as an example, based on the pixel horizontal coordinate in the image and the fixed width Wa of the calibration reference area 130a on the target 130, combined with the dimensional relationship of the first end dimension Wb, the second end width dimension Wc of the calibration feature area 130b, and the length L of the target 130, the travel distance of the first frame image A is recorded as Y0 = 0. According to the following relationship, the motion distance of the target 130 corresponding to each frame image is calculated:

[0063]

[0064] Among them, Y n-1 X is the motion distance of the target in the nth frame image. (n-1)0 and X (n-1)1 X is the pixel x-coordinate of the boundary of the calibration reference region of the nth frame image. (n-1)2 and X (n-1)3 Let L be the pixel x-coordinate of the boundary of the calibration feature region in the nth frame image, L be the length of the target, Wa be the dimension of the calibration reference region along the width direction of the target, Wc be the width dimension of the first end of the calibration feature region along the length direction of the target, Wb be the width dimension of the second end of the calibration feature region along the length direction of the target, and n be a positive integer.

[0065] In this embodiment, when the circuit breaker 110 is tripped, the movement of the target 130 corresponding to each frame of the image is calculated according to the above formula (2). The specific process is as described above and will not be detailed here.

[0066] It should be noted that the above formula (2) is the motion distance of the target 130 corresponding to each frame of the image, obtained under the condition that the shape of the calibration reference area 130a is a rectangle of fixed width and the shape of the calibration feature area 130b is a right trapezoid. The calculation method is as follows: First, the pixel coordinate of the boundary of the calibration reference area 130a in the nth frame image is marked as X. (n-1)0 and X (n-1)1 The corresponding size is the fixed width Wa of the calibration reference region 130a. Then, the x-coordinate of the pixel at the boundary of the calibration feature region 130b in the same frame image is X. (n-1)2 and X (n-1)3 When the calibration feature region 130b is shaped like a right trapezoid, the motion stroke of the target 130 is calculated based on the relationship between the geometric dimensions of the right trapezoid, the width calculated from the above proportional relationship, the length L of the target, the dimension Wa of the calibration reference region along the width direction of the target, the width Wc of the first end of the calibration feature region along the length direction of the target, and the width Wb of the second end of the calibration feature region along the length direction of the target. If the shape of the calibration feature region 130b is other than other shapes, the same calculation method can be used to obtain the motion stroke formula of the target 130 for each frame of the image.

[0067] In this embodiment, the processor 150 performs recognition, processing, and calculation on the images captured by the line scan camera 120 to obtain the motion trajectory of the target 130 in multiple frames of images. In this embodiment, the processor 150 can be an image detection system or other processors; this embodiment does not impose specific limitations.

[0068] S130. The opening and closing speed characteristics of the circuit breaker are calculated based on the relationship curve between the movement stroke and time of the target.

[0069] Specifically, based on the calculated motion stroke of the target corresponding to each frame of the image, a curve of the stroke versus time for each frame of the target 130 is plotted, thus obtaining the circuit breaker opening and closing motion stroke curve. In this embodiment, the curve of the stroke versus time for each frame of the target 130 is plotted according to the above formula (2), thus obtaining the circuit breaker opening and closing motion stroke curve. By differentiating the circuit breaker opening and closing motion stroke curve, the opening and closing speed characteristics of the circuit breaker 110 can be obtained. It should be noted that during the opening and closing process of the circuit breaker 110, the rotation angle θ of the shaft 111 is relatively small, and it is approximately assumed that the motion speed of the target 130 is equal to the opening and closing speed of the circuit breaker 110.

[0070] The present invention relates to a circuit breaker opening and closing speed measurement method based on a linear array camera. This method utilizes a linear array camera and a target set on the rotating shaft, combined with an image processing method based on edge detection, to achieve indirect measurement of the circuit breaker opening and closing speed. The number of pixels in the captured image is small, which improves the efficiency of image processing; the increase in one-dimensional pixels improves the measurement accuracy; the present invention only requires setting a target on the rotating shaft, and there is no need to change the sensor for different objects. It is less affected by the environment in which the equipment is located and can meet the requirements of online measurement.

[0071] like Figure 2 As shown, another aspect of the present invention provides a circuit breaker opening and closing speed measuring device 100 based on a line scan camera. The measuring device 100 includes a line scan camera 120, a target 130, and a processing module 150. As shown, a target 130 is provided on the rotating shaft 111 of the circuit breaker 110, and the line scan camera 120 corresponds to the target 130. In this embodiment, the target 130 is rectangular in shape.

[0072] like Figure 2 As shown, stationary contact 113 and moving contact 114 are disposed in arc-extinguishing chamber 112 for closing and opening circuit breaker 110. Arc-extinguishing chamber 112 encloses stationary contact 113 and moving contact 114. Link 115 is connected to one end of moving contact 114, and the other end of link 115, together with crank arm 116 and rotating shaft 111, constitutes an operating mechanism connected to moving contact 114. The opening and closing speeds are indirectly measured by measuring the speed characteristics of the operating mechanism. Furthermore, arc-extinguishing chamber 112, stationary contact 113, moving contact 114, and operating mechanism together constitute the structure of circuit breaker 110.

[0073] The target 130 is mounted on the rotating shaft 111 of the circuit breaker 110, and the line scan camera 120 corresponds to the target 130. The line scan camera 120 is used to acquire multiple frames of images of the target 130 as it moves with the circuit breaker 110 during opening and closing.

[0074] The processing module 150 is electrically connected to the line scan camera 120 and is used to process each frame of the target 130 image using an edge detection-based image processing method to obtain the motion distance of the target 130 corresponding to each frame, thus obtaining the relationship curve between the motion distance and time of the target 130. The processing module 150 is also used to calculate the opening and closing speed characteristics of the circuit breaker 110 based on the relationship curve between the motion distance and time of the target 130. In this embodiment, the processor 150 can be an image detection system or other processors; this embodiment does not impose specific limitations.

[0075] As shown in the figure, the target 130 is provided with a calibration reference region 130a and a calibration feature region 130b arranged at relatively intervals. The width of the calibration reference region 130a along the length of the target 130 is a fixed value. The width of the calibration feature region 130b along the length of the target 130 increases or decreases linearly from its first end to its second end; that is, the width of the first end of the calibration feature region 130b is not the same as the width of its second end. It can be that the width of the first end decreases linearly from the second end, or it can be that the width of the first end increases linearly from the second end.

[0076] Specifically, such as Figure 3 As shown, in this embodiment, the calibration reference area 130a is a fixed-width rectangle, and its width on the target 130 is Wa, serving as a reference value during the movement of the target 130. Figure 3 As shown, the calibration feature region 130b is located to the right of the calibration reference region 130a. As a change in the target 130 during its movement, the gray value of the calibration feature region 130b is consistent with the gray value of the calibration reference region 130a.

[0077] like Figure 3 As shown, in this embodiment, the width of the calibration feature region 130b increases linearly from its first end along the length of the target 130 to its second end. In this embodiment, the shape of the calibration feature region 130b is a right trapezoid, and the width of the second end of the calibration feature region 130b is Wc, meaning the lower base of the calibration feature region 130b on the target 130 is Wc. The width of the first end of the calibration feature region 130b is Wb, meaning the upper base of the calibration feature region 130b on the target 130 is Wb. The calibration feature region 130b can also have other shapes; this embodiment does not impose specific limitations.

[0078] For example, the target 130 is further provided with grayscale transition regions 130c, which are respectively located on both sides of the calibration reference region 130a and the calibration feature region 130b; wherein, the grayscale value of the grayscale transition region 130c is different from the grayscale value of the calibration reference region 130a and the calibration feature region 130b. That is, the grayscale value of the calibration reference region 130a and the calibration feature region 130b can be greater than the grayscale value of the grayscale transition region 130c, and the grayscale value of the calibration reference region 130a and the calibration feature region 130b can also be less than the grayscale value of the grayscale transition region 130c. In other words, there are no specific requirements for the specific grayscale values ​​of the calibration reference region 130a, the calibration feature region 130b, and the grayscale transition region 130c, as long as the absolute value of the difference between the grayscale values ​​of the calibration reference region 130a and the grayscale transition region 130c is greater than a preset threshold.

[0079] The grayscale transition region 130c is used to form a step grayscale gradient with the calibration reference region 130a and the calibration feature region 130b, thereby obtaining a clear edge contour and improving the accuracy of edge detection.

[0080] In a further preferred embodiment, a light source 140 is provided between the target 130 and the line scan camera 120. In this embodiment, the light source 140 is an LED light, which is used to supplement the image during shooting to avoid insufficient brightness when the exposure time of a single frame image is too short, which would cause difficulties for subsequent software recognition.

[0081] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for measuring the opening and closing speed of a circuit breaker based on a linear array camera, characterized in that, A target is provided on the rotating shaft of the circuit breaker, and the linear array camera corresponds to the target; the measurement method includes: S1, acquire multiple frames of images of the target that move with the opening and closing of the circuit breaker using the line scan camera; S2, For each frame of the target image, an image processing method based on edge detection is used to obtain the motion path of the target corresponding to each frame image, and then the relationship curve between the motion path of the target and time is obtained; S3, calculate the opening and closing speed characteristics of the circuit breaker based on the curve of the relationship between the movement stroke and time of the target; Specifically, S2 refers to the following: the target is provided with a calibration reference area and a calibration feature area that are set at relatively intervals. For each frame of the target image, an edge detection-based image processing method is used to obtain the motion path of the target corresponding to each frame image, including: An image processing method based on edge detection obtains the pixel abscissas of the calibration reference region and the calibration feature region in each frame of the image; The motion path of the target in the corresponding frame image is calculated based on the pixel abscissa of the calibration reference area and the calibration feature area and the size of the target. The width of the calibration reference area along the length of the target is a fixed value; The width of the calibration feature region at its first end along the length direction of the target increases or decreases linearly towards its second end.

2. The measurement method according to claim 1, characterized in that, Based on the pixel abscissas of the calibration reference region and the calibration feature region and the size of the target, the motion path of the target in the corresponding frame image is calculated, specifically as follows: The motion distance of the target in the corresponding frame image is calculated based on the pixel horizontal coordinates of the calibration reference region and the calibration feature region in each frame image, the width of the calibration reference region and the calibration feature region, and the length of the target.

3. The measurement method according to claim 1, characterized in that, The target is also provided with gray-scale transition regions, which are respectively located on both sides of the calibration reference region and the calibration feature region. The gray-scale values ​​of the gray-scale transition regions are different from the gray-scale values ​​of the calibration reference region and the calibration feature region.

4. The measurement method according to claim 2, characterized in that, The length of the target is calculated based on the following formula: L = θπr / 180； in, L The rotation distance of the rotating shaft surface is equal to the length of the target. θ The angle through which the shaft rotates. r The radius of the rotating shaft is given.

5. The measurement method according to any one of claims 1 to 4, characterized in that, The target has an upper boundary and a lower boundary, and the linear array camera corresponds to one of the upper and lower boundaries of the target.

6. A circuit breaker opening and closing speed measuring device based on a linear array camera, applicable to the circuit breaker opening and closing speed measuring method based on a linear array camera as described in claim 1, characterized in that, The measuring device includes a linear array camera, a target, and a processing module; The target is set on the rotating shaft of the circuit breaker, and the linear scan camera corresponds to the target. The linear array camera is used to acquire multiple frames of images of the target as it moves with the opening and closing of the circuit breaker. The processing module is electrically connected to the line scan camera and is used to apply an edge detection-based image processing method to each frame of the target image to obtain the motion path of the target corresponding to each frame image, and to obtain the relationship curve between the motion path of the target and time. The processing module is also used to calculate the opening and closing speed characteristics of the circuit breaker based on the relationship curve between the movement stroke and time of the target.

7. The measuring device according to claim 6, characterized in that, The target is provided with calibration reference areas and calibration feature areas set at relatively intervals; wherein... The width of the calibration reference area along the length of the target is a fixed value; The width of the calibration feature region at its first end along the length direction of the target increases or decreases linearly towards its second end.

8. The measuring device according to claim 7, characterized in that, The target is also provided with gray-scale transition regions, which are respectively located on both sides of the calibration reference region and the calibration feature region; the gray value of the gray-scale transition region is different from the gray value of the calibration reference region and the calibration feature region.

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