Device and method for monitoring mechanical characteristics of circuit breaker based on endoscope and camera

Abstract

The invention discloses a device and method for monitoring mechanical characteristics of a circuit breaker based on an endoscope and a camera, and relates to the technical field of image analysis. The device comprises a sight glass, a bayonet, a camera, a current sensing unit and a controller, one end of the sight glass extends into an operating mechanism box body of the circuit breaker and is used for monitoring an operating mechanism of the circuit breaker, and the current sensing unit is used for obtaining current in an opening and closing coil of the circuit breaker; the method comprises the steps that a current sensing unit obtains a real-time current value in an opening and closing coil of the circuit breaker and sends the real-time current value to a controller, the controller controls a camera to shoot and obtain a multi-frame mechanical characteristic image of an operating mechanism of the circuit breaker, and the mechanical characteristics of the circuit breaker are extracted from the multi-frame mechanical characteristic image; through the sight glass extending into the operating mechanism box body of the circuit breaker, the camera can monitor and obtain multiple frames of mechanical characteristic images of the operating mechanism in the closed operating mechanism box body of the circuit breaker through the bayonet and the sight glass, and then the mechanical characteristics of the circuit breaker can be obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of image analysis, and in particular to a device and method for monitoring mechanical characteristics of a circuit breaker based on an endoscope and a camera. Background Art

[0002] High-voltage circuit breakers play a key role in the power grid. When a short-circuit fault occurs in the power grid, they can quickly cut off the short-circuit current to avoid more serious accidents. The operating mechanism is an important part of the high-voltage circuit breaker. According to statistics, more than 50% of the failures of high-voltage circuit breakers are caused by the operating mechanism, and these failures are mainly mechanical failures.

[0003] By testing the mechanical characteristics of the operating mechanism, mechanical failures can be accurately diagnosed. The commonly used method is to install linear displacement sensors or angle sensors, but these sensors need to be fixed on the operating mechanism, which may increase the risk of mechanical failure. Therefore, it is proposed to use high-speed cameras instead of sensors to analyze the mechanical characteristics of the operating mechanism by capturing the motion images of the circuit breaker switches.

[0004] The authorization announcement number is CN117710367B, and the name is a method, device and related equipment for detecting mechanical characteristic images of high-voltage circuit breakers. During the closing and opening process of the high-voltage circuit breaker, the marking points on the high-voltage circuit breaker are photographed to obtain multiple frames of mechanical characteristic images, and the marking points are located on the pull rod of the operating mechanism of the high-voltage circuit breaker; the position of the marking points in each frame of the mechanical characteristic image is detected by the background difference method; according to the position of the marking points in each frame of the mechanical characteristic image, the mechanical stroke characteristic curve of the high-voltage circuit breaker is drawn. When this technical solution is actually applied on site, since the operating mechanism box of the on-site circuit breaker is in a closed state, the camera cannot directly monitor in real time to obtain multiple frames of mechanical characteristic images of the circuit breaker's switch, and thus the mechanical characteristics of the circuit breaker cannot be obtained.

[0005] The application publication number is CN118883028A, and the name is a method and system for measuring the mechanical characteristics of high-voltage circuit breakers based on machine vision. It includes the following steps: Step 1: Synchronously trigger the high-speed camera to shoot when the circuit breaker is in action; Step 2: The high-speed camera collects the circuit breaker video or image sequence; Step 3: Preprocess the video or image sequence; Step 4: Identify the key feature points of the preprocessed video or image sequence; Step 5: Calculate the pixel displacement of the key feature points with each image frame by the optical flow method; Step 6: Cluster the displacement of the key feature points to eliminate background feature points and interference displacement; Step 7: Convert the target pixel displacement of each image frame into a spatial coordinate displacement to obtain the target coordinates under the spatial coordinates, and then obtain the motion speed data of the operating mechanism, and calculate and analyze the target coordinates and motion speed data to obtain the mechanical characteristic parameters. When this technical solution is actually applied on site, since the operating mechanism box of the on-site circuit breaker is in a closed state, the camera cannot directly monitor and obtain the multi-frame mechanical characteristic images of the switch of the circuit breaker in real time, and thus cannot obtain the mechanical characteristics of the circuit breaker. Summary of the invention

[0006] The present invention provides a device and method for monitoring the mechanical characteristics of a circuit breaker based on an endoscope and a camera, which solves the technical problem that the camera cannot monitor and obtain multi-frame mechanical characteristic images of an operating mechanism in a closed operating mechanism box of a circuit breaker.

[0007] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows:

[0008] A device for monitoring the mechanical characteristics of a circuit breaker based on an endoscope and a camera comprises a scope, a bayonet, a camera, a current sensing unit and a controller. The scope, the bayonet and the camera are connected in sequence. One end of the scope extends into the operating mechanism box of the circuit breaker and is used to monitor the operating mechanism of the circuit breaker. The current sensing unit is used to obtain the current in the opening and closing coil of the circuit breaker. The bayonet, the camera and the controller are all located outside the operating mechanism box of the circuit breaker. The current sensing unit is electrically connected to the controller, and the controller is electrically connected to the camera and communicates with it.

[0009] A further technical solution is that the current sensing unit is located in the operating mechanism box of the circuit breaker, the current sensing unit includes an open-clamp Hall current sensor and an acquisition card, the open-clamp Hall current sensor is arranged on the opening and closing coil of the circuit breaker and is used to sense the current in the opening and closing coil, the open-clamp Hall current sensor is electrically connected to the acquisition card, and the acquisition card is electrically connected to the controller.

[0010] A further technical solution is that the open clamp Hall current sensor is electrically connected to the input end of the acquisition card, the output end of the acquisition card is electrically connected to one end of the cable, and the other end of the cable passes through the operating mechanism box of the circuit breaker and is connected to the input end of the controller.

[0011] A method for monitoring the mechanical characteristics of a circuit breaker based on an endoscope and a camera comprises a monitoring step, wherein the monitoring step comprises a current sensing unit obtaining a real-time current value in an opening and closing coil of the circuit breaker and sending the real-time current value to a controller, the controller generating a corresponding camera control signal based on the obtained real-time current value and controlling the camera to operate accordingly; when the controller controls the camera to capture and obtain multiple frames of mechanical characteristic images of an operating mechanism of the circuit breaker, the mechanical characteristics of the circuit breaker are extracted from the multiple frames of mechanical characteristic images.

[0012] A further technical solution is that: in the monitoring step, the step of generating a corresponding camera control signal based on the obtained real-time current value includes: when the real-time current value I(t) exceeds the current threshold value I set in advance threshold And the duration exceeds the time threshold T threshold When , a camera trigger signal is generated;

[0013]

[0014] In formula (1), Trigger is the control signal generated by the controller. When the control signal is 1, it is the camera trigger signal. I(t) is the real-time current value. threshold is the current threshold, duration is the duration, T threshold is the time threshold.

[0015] A further technical solution is that: the current threshold I threshold 0.2A~0.3A, time threshold T threshold It is 3 milliseconds to 4 milliseconds.

[0016] A further technical solution is that before the step of extracting the mechanical characteristics of the circuit breaker, a step of preprocessing multiple frames of mechanical characteristic images to obtain preprocessed images is included, and the mechanical characteristics of the circuit breaker are extracted from the preprocessed images.

[0017] A further technical solution is that the image preprocessing step includes removing noise, adjusting contrast, brightness and correction.

[0018] A further technical solution is that the step of extracting and obtaining the mechanical characteristics of the circuit breaker includes extracting and obtaining the gradient direction histogram of each frame image, generating a response diagram of each frame image based on the gradient direction histogram, calculating and obtaining the displacement of the operating mechanism of the circuit breaker of each frame image based on the response diagram, and generating a displacement diagram, i.e., the mechanical characteristics of the circuit breaker, based on the displacement of the operating mechanism of the circuit breaker of each frame image.

[0019] A further technical solution is that: in the step of extracting and obtaining the mechanical characteristics of the circuit breaker, the HOG feature of the gradient direction histogram is extracted according to formula (2) to obtain the gradient direction histogram of each frame image;

[0020] HOG=HOG() (2)

[0021] In formula (2), HOG() is the HOG feature extraction function, and HOG is the gradient direction histogram;

[0022] Generate the response map of each frame image according to formula (3) based on the gradient direction histogram;

[0023] R=Response(HOG) (3)

[0024] In formula (3), Response() is the response graph extraction function, and R is the response graph;

[0025] Based on the response diagram, the displacement (Δx, Δy) of the operating mechanism of the circuit breaker of each frame image is calculated according to equations (4) and (5);

[0026]

[0027] In formula (4), Δx is the horizontal displacement of the target on the operating mechanism; Used to find the maximum value position in the cross-correlation result, so as to obtain the displacement in the horizontal direction; i is the pixel number in the horizontal direction; M is the maximum pixel number in the horizontal direction; j is the pixel number in the vertical direction; N is the maximum pixel number in the vertical direction; I1(i,j) is the pixel value in the previous response image of two adjacent response images; I2(i,j) is the pixel value in the next response image of two adjacent response images; a is the horizontal coordinate value corresponding to the maximum pixel value in the two response images;

[0028]

[0029] In formula (5), Δy is the vertical displacement of the target on the operating mechanism; Used to find the maximum value position in the cross-correlation result, so as to obtain the displacement in the vertical direction; b is the vertical coordinate value corresponding to the maximum pixel value in the two response images.

[0030] A further technical solution is that the multi-frame mechanical characteristic images of the operating mechanism are multi-frame mechanical characteristic images of a switch of the operating mechanism.

[0031] The beneficial effects of adopting the above technical solution are:

[0032] A device for monitoring the mechanical characteristics of a circuit breaker based on an endoscope and a camera, comprising a scope, a bayonet, a camera, a current sensing unit and a controller, wherein one end of the scope is inserted into the operating mechanism box of the circuit breaker and is used to monitor the operating mechanism of the circuit breaker, and the current sensing unit is used to obtain the current in the opening and closing coil of the circuit breaker, and the monitoring step comprises the current sensing unit obtaining the real-time current value in the opening and closing coil of the circuit breaker and sending it to the controller, the controller controlling the camera to capture and obtain multiple frames of mechanical characteristic images of the operating mechanism of the circuit breaker, and extracting and obtaining the mechanical characteristics of the circuit breaker from the multiple frames of mechanical characteristic images. By inserting the scope into the operating mechanism box of the circuit breaker, the camera can monitor and obtain multiple frames of mechanical characteristic images of the operating mechanism in the closed operating mechanism box of the circuit breaker through the bayonet and the scope, and thus can obtain the mechanical characteristics of the circuit breaker.

[0033] The current sensing unit includes an open clamp type Hall current sensor and an acquisition card, which can accurately acquire the coil current signal in real time.

[0034] A method for monitoring the mechanical characteristics of a circuit breaker based on an endoscope and a camera comprises a monitoring step, wherein the monitoring step comprises a current sensing unit obtaining a real-time current value in an opening and closing coil of the circuit breaker and sending the real-time current value to a controller, the controller generating a corresponding camera control signal based on the obtained real-time current value and controlling the camera to operate accordingly; when the controller controls the camera to capture and obtain multiple frames of mechanical characteristic images of an operating mechanism of the circuit breaker, the mechanical characteristics of the circuit breaker are extracted from the multiple frames of mechanical characteristic images.

[0035] Camera trigger condition: When the real-time current value I(t) exceeds the pre-set current threshold I threshold And the duration exceeds the time threshold T threshold The dual threshold trigger mechanism reduces false triggering and improves triggering accuracy.

[0036] Before the step of extracting and obtaining the mechanical characteristics of the circuit breaker, multiple frames of mechanical characteristic images are subjected to image preprocessing to make the images clearer and easier to analyze, and ensure that the components in the images maintain a stable and accurate coordinate system.

[0037] The gradient direction histogram of each frame image is extracted, and the response map of each frame image is generated based on the gradient direction histogram. The displacement of the operating mechanism of the circuit breaker of each frame image is calculated based on the response map, and the displacement map is generated based on the displacement of the operating mechanism of the circuit breaker of each frame image. The algorithm uses the characteristic changes in the response map to achieve accurate calculation of component displacement, thereby extracting the displacement information during the circuit breaker operation process.

[0038] Please refer to the detailed description of the specific implementation method. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1It is a distribution map of the installation locations of fiber endoscopes;

[0040] Figure 2 It is a curve diagram of the closing current in the opening and closing coil under ideal conditions;

[0041] Figure 3 It is the data flow diagram of the present invention.

[0042] Among them: 1 endoscope, 2 bayonet, 3 camera, 4 circuit breaker spindle. DETAILED DESCRIPTION

[0043] Currently, the method of acquiring the mechanical characteristics of circuit breakers through images has not fully considered the situation when the operating mechanism box is in a closed state. In this state, most key components cannot be directly exposed to the camera's field of view, making it difficult to directly capture their movement process with a high-speed camera.

[0044] The present application uses an endoscope device in conjunction with a high-speed camera to make up for the deficiency that the camera cannot directly observe the movement of components, and effectively captures the movement process of key components by changing the optical path.

[0045] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0046] In the following description, many specific details are set forth to facilitate a full understanding of the present application, but the present application may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0047] Embodiment 1:

[0048] like Figure 1As shown, the present invention discloses a device for monitoring the mechanical characteristics of a circuit breaker based on an endoscope and a camera, comprising an endoscope 1, a bayonet 2, a camera 3, a current sensing unit and a controller. The endoscope 1, the bayonet 2 and the camera 3 are connected in sequence. One end of the endoscope 1 extends into the operating mechanism box of the circuit breaker and is used to monitor the switch of the circuit breaker. The current sensing unit is located in the operating mechanism box of the circuit breaker. The bayonet 2, the camera 3 and the controller are all located outside the operating mechanism box of the circuit breaker. The current sensing unit comprises an open clamp type Hall current sensor and an acquisition card. The open clamp type Hall current sensor is fixedly connected to the opening and closing coil of the circuit breaker and is used to sense the current in the opening and closing coil. The open clamp type Hall current sensor is electrically connected to the input end of the acquisition card, the output end of the acquisition card is electrically connected to one end of a cable, the other end of the cable passes through the operating mechanism box of the circuit breaker and is connected to the input end of the controller. The controller is electrically connected to and communicates with the camera 3. The endoscope 1, the bayonet 2, the camera 3, the current sensing unit and the controller form a monitoring device.

[0049] System hardware construction instructions:

[0050] Endoscope 1 device installation:

[0051] Select a suitable endoscope: The endoscope 1 is an industrial fiber endoscope. The models of industrial fiber endoscopes are IF6PD4 / IF2D5 / IF4D5 / IF4S5. According to the internal structure of the circuit breaker and the switch components to be monitored, select a suitable endoscope type, such as a flexible endoscope or a rigid endoscope. The endoscope should have high resolution and a large viewing angle to ensure that the movement of key components can be clearly captured.

[0052] Installation and commissioning:

[0053] like Figure 1 As shown, it is the place where the endoscope 1 is installed and fixed. The endoscope is installed at the observation port of the circuit breaker or a suitable position. One end of the endoscope 1 is inserted into the operating mechanism box of the circuit breaker and is connected and fixed by a fixing piece. By adjusting the optical path and the angle of the endoscope, the end of the endoscope 1 inserted into the operating mechanism box of the circuit breaker can monitor the circuit breaker main shaft 4 of the circuit breaker switch, ensuring that key components, such as the iron core, contacts, etc., are within the field of view of the endoscope, and the image is clear and stable. Ensure that the optical path transmission between the endoscope and the high-speed camera is not disturbed.

[0054] Selection and installation of high-speed cameras:

[0055] Camera 3 selection: Choose a suitable high-speed camera with sufficient acquisition speed and resolution to ensure that the instantaneous details of the circuit breaker action can be captured. It is recommended to choose a camera with high frame rate and low latency response. The camera 3 model is HT-XG51GC-T.

[0056] Camera 3 is connected to the endoscope: Mount 2 is an optical mount, which connects the high-speed camera to the endoscope through an optical fiber or lens connector, namely, mount 2, to ensure that the light collected by the endoscope can be effectively transmitted to the camera to form a high-quality image.

[0057] Current sensor installation:

[0058] Select current sensor: Choose a high-precision open-clamp Hall current sensor that can monitor the current changes of the circuit breaker opening and closing coils in real time.

[0059] Installation location: Install the current sensor close to the circuit breaker opening and closing coil to ensure accurate acquisition of the coil current signal.

[0060] Circuit breaker action triggering and current monitoring:

[0061] The opening and closing coil of the high-voltage circuit breaker is activated when it receives 220V DC power, driving the iron core to move, thereby triggering the opening and closing operation of the circuit breaker. In order to capture this high-speed movement process, the controller in the system monitors the changes in the coil current in real time through the current sensing unit to control the triggering of the high-speed camera, so that the camera can be started at the critical moment.

[0062] A 0.2-level precision open-clamp Hall current sensor is used in conjunction with the NI-USB-4431 acquisition card to form a current sensing unit, which accurately collects coil current signals in real time to ensure synchronous capture of the circuit breaker's operating status.

[0063] Endoscope and optical path optimization:

[0064] The application of the endoscope device effectively solves the line of sight limitation of the camera directly observing the switch movement. By changing the optical path, the endoscope realizes clear observation of the key components inside the circuit breaker, ensuring that the details of the movement process can still be fully captured in the complex structure.

[0065] After the optical path is adjusted, the movement process of key components can be accurately transmitted to the field of view of the high-speed camera, making the captured image more stable and clear, which is helpful for subsequent motion analysis.

[0066] Endoscope optimizes observation angle:

[0067] The endoscope solves the limitation that the camera cannot directly observe the movement of components. By adjusting the optical path, it ensures the effective capture of key components inside the circuit breaker and improves the stability and clarity of image acquisition.

[0068] Among them, the endoscope, the bayonet, the camera, the open clamp type Hall current sensor, the acquisition card and the controller itself as well as the corresponding connection technology are existing technologies and will not be described in detail here.

[0069] Embodiment 2:

[0070] The present invention discloses a method for monitoring the mechanical characteristics of a circuit breaker based on an endoscope and a camera. The method is based on the device for monitoring the mechanical characteristics of a circuit breaker based on an endoscope and a camera described in Example 1 and includes a monitoring step.

[0071] The monitoring steps include the current sensing unit obtaining the real-time current value in the opening and closing coil of the circuit breaker and informing the controller; after the controller obtains the real-time current value, the controller generates a corresponding camera control signal based on the real-time current value and sends it to camera 3; after camera 3 obtains the camera control signal, it works accordingly based on the camera control signal; when the controller controls camera 3 to capture multiple frames of mechanical characteristic images of the switch of the circuit breaker based on the camera control signal, the controller obtains multiple frames of mechanical characteristic images from camera 3, preprocesses the multiple frames of mechanical characteristic images to obtain preprocessed images, and extracts the mechanical characteristics of the circuit breaker from the preprocessed images.

[0072] The monitoring step is implemented based on the monitoring module in the monitoring device. The monitoring module is a program module corresponding to the monitoring step. The monitoring module in the controller in the monitoring device is run to implement the monitoring step. The monitoring device and the monitoring module form the system of the present application.

[0073] The monitoring steps are detailed as follows:

[0074] In the monitoring step, the step of generating a corresponding camera control signal based on the real-time current value includes: when the real-time current value I(t) exceeds the current threshold value I set in advance threshold And the duration exceeds the time threshold T threshold When , a camera trigger signal is generated; otherwise, no camera trigger signal is generated. The trigger condition is expressed in formula (1) and is described in detail as follows.

[0075] Precise control of camera trigger logic:

[0076] Triggering based on coil current: Real-time monitoring of coil current changes is used to trigger the camera based on coil current changes, thus achieving synchronous control of the high-speed camera. Since the change in coil current occurs before the circuit breaker is actuated, the camera can be triggered in advance by taking advantage of the fact that the current change precedes the circuit breaker actuation, so that the camera can accurately capture the starting moment of the circuit breaker actuation, avoiding delays or missed shots, effectively capturing the starting moment of the circuit breaker actuation, and improving the time accuracy of the recording.

[0077] Dual threshold trigger mechanism: Dual threshold logic, i.e. current intensity and duration, ensures that the camera is triggered only when key actions occur, reducing false triggers and improving trigger accuracy. The trigger logic combines the dual conditions of current size and duration, reducing the interference of short-term current fluctuations on triggering and reducing the risk of false triggers. The camera is triggered only when both the current intensity and duration meet the set thresholds, ensuring the accuracy of shooting.

[0078] Camera trigger logic implementation:

[0079] 1) Current signal acquisition and processing

[0080] Current acquisition: The current signal of the opening and closing coil is collected in real time through an open clamp Hall current sensor and transmitted to an acquisition card, such as the NI-USB-4431 acquisition card.

[0081] Data preprocessing: Based on the collected current signal, the acquisition card removes noise through calculation and filtering to ensure the accuracy of the signal.

[0082] like Figure 2 As shown, it is a curve diagram of closing current, in which the horizontal axis is time, in milliseconds ms, and the vertical axis is current, in amperes A.

[0083] 2) Trigger logic design

[0084] Dual threshold trigger condition setting: Set two trigger conditions.

[0085] Current threshold I threshold : The current signal exceeds the set amplitude threshold, triggering the camera to start.

[0086] Time threshold T threshold :The camera is triggered only after the current signal lasts for a certain period of time to avoid false triggering caused by short-term fluctuations.

[0087] Trigger signal generation: When the amplitude and duration of the current signal meet the set threshold, a trigger signal is generated. The trigger signal can be output as a digital pulse and transmitted to the camera after adjusting the pulse width.

[0088] 3) Camera triggering and image acquisition

[0089] Trigger signal transmission: The trigger signal generated by current signal processing is output to the trigger input terminal of the high-speed camera to start the camera to acquire images.

[0090] Camera trigger condition settings:

[0091] In order to avoid false triggering of the camera caused by irrelevant current fluctuations, this application adopts dual trigger threshold logic: setting the thresholds of current amplitude and duration at the same time.

[0092] Only when the real-time current value I(t) exceeds the pre-set current threshold I threshold And the duration exceeds the time threshold T threshold , the controller generates a camera trigger signal and sends it to the camera; when the real-time current value I(t) exceeds the current threshold I threshold And the duration does not exceed the time threshold T threshold, the camera will not be triggered, thus reducing the possibility of false triggering.

[0093] The trigger condition is expressed by formula (1):

[0094]

[0095] In formula (1), Trigger is the control signal generated by the controller. When the control signal is 1, it is the camera trigger signal. I(t) is the real-time current value. threshold is the current threshold, duration is the duration, T threshold is the time threshold.

[0096] In this application, the current threshold I threshold Can be set to 0.2~0.3A, time threshold T threshold The current threshold I in Example 1 is set to 3 to 4 milliseconds. threshold is 0.25A, time threshold T threshold Set to 3.5 milliseconds.

[0097] When I(t)≥I threshold And the duration exceeds T threshold , the camera is triggered.

[0098] If the real-time current value suddenly increases to more than I threshold , but not continuously T threshold , the camera will not be triggered to avoid false triggering.

[0099] Camera trigger signal output and camera start.

[0100] Image acquisition settings: Set the camera’s shooting timing and frame rate to ensure that image data can be captured at the critical moment of the circuit breaker action. Adjust the camera’s exposure time and focus settings according to the experimental requirements to obtain clear images of component movement.

[0101] Image data acquisition:

[0102] The high-speed camera collects image sequences during the circuit breaker operation process under the trigger signal, providing image pairs at the front and back moments as the basis for displacement extraction.

[0103] When the dual threshold conditions are met, the controller generates a digital pulse signal and transmits it to the camera trigger input. The pulse width of the signal can be adjusted according to different environments to ensure that the high-speed camera can accurately respond to the trigger signal under various conditions.

[0104] Through this triggering method, the camera can accurately capture the startup moment and the entire action process of the circuit breaker, avoiding the generation of redundant images and reducing storage and data processing pressure.

[0105] In the monitoring step, the image preprocessing step includes removing noise, adjusting contrast, brightness and correction.

[0106] Image preprocessing:

[0107] The images captured by the camera are preliminarily processed to remove noise, adjust contrast and brightness, and make the images clearer and easier to analyze.

[0108] Use image processing software to correct the image to ensure that the parts in the image maintain a stable and accurate coordinate system.

[0109] like Figure 3 As shown, the image marked with words "pre-processed image" on the left side of the figure is the pre-processed image.

[0110] In the monitoring step, the step of extracting and obtaining the mechanical characteristics of the circuit breaker includes extracting and obtaining the gradient direction histogram of each frame image, generating a response map of each frame image based on the gradient direction histogram, calculating and obtaining the displacement of the switch of the circuit breaker of each frame image based on the response map, and generating a displacement map, i.e., the mechanical characteristics of the circuit breaker, based on the displacement of the switch of the circuit breaker of each frame image. The details are as follows.

[0111] like Figure 3 As shown, in the upper part of the figure, the image marked with the words "reference picture" is the previous image, and the target frame in the image marked with the words "reference picture" is the line segment on the switch of the operating mechanism, that is, the target. The image marked with the words "reference picture" is subjected to HOG feature extraction to obtain the previous HOG map, and then the previous response map is obtained by processing the response map extraction function. In the lower part of the figure, the image marked with the words "target picture" is the next image, and the target frame in the image marked with the words "target picture" is the line segment on the switch of the operating mechanism, that is, the target. The image marked with the words "target picture" is subjected to HOG feature extraction to obtain the next HOG map, and then the next response map is obtained by processing the response map extraction function. Until all images are processed, all response maps are obtained. Based on all response maps, the displacement of the switch of the circuit breaker of each frame image is calculated respectively, and the displacement map, that is, the mechanical characteristics of the circuit breaker, is generated based on the displacement of the switch of the circuit breaker of each frame image. In the displacement map, the horizontal axis is time, in milliseconds ms, and the vertical axis is displacement, in angles.

[0112] In the step of extracting and obtaining the mechanical characteristics of the circuit breaker, the HOG feature extraction of the gradient direction histogram is performed according to formula (2) to obtain the gradient direction histogram of each frame image.

[0113] HOG=HOG() (2)

[0114] In formula (2), HOG() is the HOG feature extraction function, and HOG is the gradient direction histogram.

[0115] HOG feature extraction: Perform HOG feature extraction on each frame of image using the gradient directional histogram to generate a HOG feature map. This feature map is used to capture the edge information and texture features of key components of the circuit breaker, facilitating subsequent target tracking and analysis.

[0116] In the step of extracting and obtaining the mechanical characteristics of the circuit breaker, a response map of each frame image is generated according to formula (3) based on the gradient direction histogram.

[0117] R=Response(HOG) (3)

[0118] In formula (3), Response() is the response graph extraction function, and R is the response graph.

[0119] Response graph generation:

[0120] A response map is generated based on the HOG feature, which highlights the position change of the component with the feature matching strength at different positions, and highlights the position and feature response strength of the target component in the image, providing a basis for the tracking algorithm.

[0121] In the step of extracting the mechanical characteristics of the circuit breaker, the displacement (Δx, Δy) of the switch of the circuit breaker in each frame of the image is calculated based on the response diagram according to equations (4) and (5).

[0122]

[0123] In formula (4), Δx is the displacement of the target in the horizontal direction; Used to find the maximum value position in the cross-correlation result, so as to obtain the displacement in the horizontal direction; i is the pixel number in the horizontal direction; M is the maximum pixel number in the horizontal direction; j is the pixel number in the vertical direction; N is the maximum pixel number in the vertical direction; I1(i,j) is the pixel value in the previous response image between two adjacent response images; I2(i,j) is the pixel value in the next response image between two adjacent response images; a is the horizontal coordinate value corresponding to the maximum pixel value in the two response images.

[0124]

[0125] In formula (5), Δy is the displacement of the target in the vertical direction; Used to find the maximum value position in the cross-correlation result, so as to obtain the displacement in the vertical direction; b is the vertical coordinate value corresponding to the maximum pixel value in the two response images.

[0126] Displacement calculation:

[0127] The motion of the key components of the circuit breaker is tracked according to the response diagram, and the displacements in the x-axis and y-axis directions in the images at the previous and next moments are calculated.

[0128] The continuous positioning of the target component is achieved through the response diagram, and the displacement at each moment is calculated.

[0129] The algorithm uses the characteristic changes in the response diagram to accurately calculate the displacement of the components, thereby extracting the displacement information during the circuit breaker operation process.

[0130] In the step of extracting and obtaining the mechanical characteristics of the circuit breaker, a displacement map, namely the mechanical characteristics of the circuit breaker, is generated based on the displacement of the switch of the circuit breaker in each frame image, as described in detail below.

[0131] Displacement map generation:

[0132] According to the displacement of the target component in the x-axis and y-axis directions, a displacement diagram is generated to intuitively display the motion trajectory of the displacement changes of the circuit breaker component at different time points during the operation process.

[0133] The calculated displacement information is converted into a displacement map to generate a motion trajectory map of the circuit breaker components for subsequent analysis and fault diagnosis.

[0134] Embodiment 3:

[0135] The present invention discloses a method for monitoring the mechanical characteristics of a circuit breaker based on an endoscope and a camera, including the method for monitoring the mechanical characteristics of a circuit breaker based on an endoscope and a camera described in Example 2, and further including the following steps:

[0136] Displacement map output:

[0137] The output displacement map and camera trigger timestamp information, combined with the camera trigger time, provide a complete status record of the circuit breaker action process, providing high-precision data support for subsequent fault analysis and status monitoring.

[0138] Embodiment 4:

[0139] The present invention discloses a method for monitoring the mechanical characteristics of a circuit breaker based on an endoscope and a camera, comprising a computer, a first communication unit and the method for monitoring the mechanical characteristics of a circuit breaker based on an endoscope and a camera described in Example 3, wherein the monitoring device in Example 1 further comprises a second communication unit, the controller of the monitoring device is wiredly connected to the second communication unit, the computer is fixed in a monitoring room, the computer is wiredly connected to the first communication unit and communicates, the first communication unit on the computer side is wiredly connected to the second communication unit on the controller side in Example 1 and communicates, and further comprises the following steps:

[0140] Data storage and management:

[0141] 1) Image and displacement data storage

[0142] The controller of the monitoring device sends the collected images and generated displacement map data to the computer for storage via the second communication unit on the controller side. To avoid wasting storage space, the data collection frequency and storage time should be controlled according to the trigger logic to avoid redundant data.

[0143] Data storage should use efficient compression algorithms or cloud storage solutions to ensure data security and facilitate subsequent processing and analysis.

[0144] 2) Data processing and analysis

[0145] The computer combines the collected images and displacement data for subsequent fault analysis, condition monitoring and performance evaluation. The automated analysis system can extract key fault indicators and detect potential problems in advance.

[0146] Embodiment 5:

[0147] Embodiment 5 is different from Embodiment 4 in that a mobile terminal is used instead of a fixed terminal, that is, a laptop computer is used instead of a computer, so as to facilitate on-site work by maintenance personnel.

[0148] The present invention discloses a method for monitoring the mechanical characteristics of a circuit breaker based on an endoscope and a camera, including a laptop computer and the method for monitoring the mechanical characteristics of a circuit breaker based on an endoscope and a camera as described in Example 3. The monitoring device in Example 1 also includes a communication unit, the controller of the monitoring device is connected to the communication unit by wire, and the laptop computer is wirelessly connected to and communicates with the communication unit on the controller side in Example 1. The similarities are not repeated here.

[0149] Embodiment 6:

[0150] The present invention discloses a method for monitoring the mechanical characteristics of a circuit breaker based on an endoscope and a camera, including the method for monitoring the mechanical characteristics of a circuit breaker based on an endoscope and a camera described in Example 2, and further including the following steps:

[0151] System testing and optimization:

[0152] 1) System debugging

[0153] Thoroughly test the system to ensure that the endoscope, camera, sensor, and trigger logic are working in harmony. Check the camera’s trigger timing, image clarity, and accuracy of displacement calculations.

[0154] 2) System Optimization

[0155] Different circuit breaker action scenarios are simulated in the experiment to verify the performance of the system under different operating environments, and to optimize the trigger threshold and image acquisition parameters.

[0156] Embodiment 7:

[0157] The difference between Example 7 and Example 2 is that the current sensing unit is replaced by a current transformer, and any existing current transformer is used to achieve the technical function of current sensing.

[0158] The invention discloses a method for monitoring mechanical characteristics of a circuit breaker based on an endoscope and a camera, comprising a monitoring device and a monitoring step.

[0159] The monitoring device includes an endoscope 1, a bayonet 2, a camera 3, a current transformer and a controller. The endoscope 1, the bayonet 2 and the camera 3 are connected in sequence. One end of the endoscope 1 extends into the operating mechanism box of the circuit breaker and is used to monitor the switch of the circuit breaker. The current transformer is located in the operating mechanism box of the circuit breaker and is used to sense the current in the opening and closing coils. The bayonet 2, the camera 3 and the controller are all located outside the operating mechanism box of the circuit breaker. The output end of the current transformer is electrically connected to one end of the cable, and the other end of the cable is connected to the input end of the controller after passing through the operating mechanism box of the circuit breaker. The controller is electrically connected to the camera 3 and communicates with each other.

[0160] The monitoring steps include using a current transformer to obtain the real-time current value in the opening and closing coil of the circuit breaker and sending it to a controller, and the controller generates a corresponding camera control signal based on the obtained real-time current value and controls the camera to work accordingly; when the controller controls camera 3 to capture multiple frames of mechanical characteristic images of the operating mechanism of the circuit breaker, the mechanical characteristics of the circuit breaker are extracted from the multiple frames of mechanical characteristic images.

[0161] In Example 7, the monitoring step can be implemented by the method in the prior art solution. Through the improvement of the hardware part, that is, the structural combination of the endoscope 1, the bayonet 2, the camera 3, the current transformer and the controller, one end of the endoscope 1 is inserted into the operating mechanism box of the circuit breaker and used to monitor the switch of the circuit breaker, so that multiple frames of mechanical characteristic images of the switch of the operating mechanism in the closed operating mechanism box of the circuit breaker can be monitored and obtained, and then the mechanical characteristics of the circuit breaker can be obtained.

[0162] Embodiment 8:

[0163] Embodiment 8 differs from Embodiment 6 in that a target for identification is marked at any visible position of the operating mechanism, and monitoring can be achieved by pointing one end of the endoscope 1 inserted into the operating mechanism box of the circuit breaker toward the target. The similarities are not repeated here.

[0164] Embodiment 9:

[0165] Embodiment 9 is different from Embodiment 6 in that the current sensing unit includes an open clamp Hall current sensor and an acquisition card, which can accurately acquire the coil current signal in real time. The similarities are not repeated here.

[0166] Embodiment 10:

[0167] Embodiment 10 is different from Embodiment 6 in that the camera trigger condition is: when the real-time current value I(t) exceeds the current threshold value I set in advance threshold And the duration exceeds the time threshold T threshold When the camera is in the state of being triggered, a camera trigger signal is generated. The dual threshold trigger mechanism reduces false triggering and improves the accuracy of triggering. The similarities are not repeated here.

[0168] Embodiment 11:

[0169] Embodiment 11 differs from Embodiment 6 in that, before the step of extracting the mechanical characteristics of the circuit breaker, multiple frames of mechanical characteristic images are subjected to image preprocessing to make the images clearer and easier to analyze, ensuring that the components in the images maintain a stable and accurate coordinate system. The similarities are not repeated here.

[0170] Embodiment 12:

[0171] The difference between Example 12 and Example 6 is that a gradient direction histogram of each frame image is extracted, a response map of each frame image is generated based on the gradient direction histogram, the displacement of the operating mechanism of the circuit breaker of each frame image is calculated based on the response map, and a displacement map is generated based on the displacement of the operating mechanism of the circuit breaker of each frame image. The algorithm uses the characteristic changes in the response map to achieve accurate calculation of the displacement of the component, thereby extracting the displacement information during the circuit breaker operation process, and the similarities are not repeated here.

Claims

1. A device for monitoring mechanical characteristics of a circuit breaker based on an endoscope and a camera, characterized in that: The invention comprises an endoscope (1), a bayonet (2), a camera (3), a current sensing unit and a controller. The endoscope (1), the bayonet (2) and the camera (3) are connected in sequence. One end of the endoscope (1) extends into the operating mechanism box of the circuit breaker and is used to monitor the operating mechanism of the circuit breaker. The current sensing unit is used to obtain the current in the opening and closing coil of the circuit breaker. The bayonet (2), the camera (3) and the controller are all located outside the operating mechanism box of the circuit breaker. The current sensing unit is electrically connected to the controller. The controller is electrically connected to the camera (3) and communicates with each other.

2. The device for monitoring mechanical characteristics of a circuit breaker based on an endoscope and a camera according to claim 1, characterized in that: The current sensing unit is located in the operating mechanism box of the circuit breaker. The current sensing unit includes an open-clamp Hall current sensor and an acquisition card. The open-clamp Hall current sensor is arranged on the opening and closing coil of the circuit breaker and is used to sense the current in the opening and closing coil. The open-clamp Hall current sensor is electrically connected to the acquisition card, and the acquisition card is electrically connected to the controller.

3. The device for monitoring mechanical characteristics of a circuit breaker based on an endoscope and a camera according to claim 2, characterized in that: The open clamp type Hall current sensor is electrically connected to the input end of the acquisition card, the output end of the acquisition card is electrically connected to one end of the cable, and the other end of the cable is connected to the input end of the controller after passing through the operating mechanism box of the circuit breaker.

4. A method for monitoring mechanical characteristics of a circuit breaker based on an endoscope and a camera, used in the device for monitoring mechanical characteristics of a circuit breaker based on an endoscope and a camera as claimed in any one of claims 1 to 3, characterized in that: The method comprises a monitoring step, wherein a current sensing unit obtains a real-time current value in the opening and closing coil of a circuit breaker and sends the real-time current value to a controller, the controller generates a corresponding camera control signal based on the obtained real-time current value and controls the camera (3) to work accordingly; when the controller controls the camera (3) to capture a multi-frame mechanical characteristic image of the operating mechanism of the circuit breaker, the mechanical characteristics of the circuit breaker are extracted from the multi-frame mechanical characteristic image.

5. The method for monitoring mechanical characteristics of a circuit breaker based on an endoscope and a camera according to claim 4, characterized in that: In the monitoring step, the step of generating a corresponding camera control signal based on the obtained real-time current value includes: when the real-time current value I(t) exceeds the current threshold value I set in advance threshold And the duration exceeds the time threshold T threshold When , a camera trigger signal is generated; In formula (1), Trigger is the control signal generated by the controller. When the control signal is 1, it is the camera trigger signal. I(t) is the real-time current value. threshold is the current threshold, duration is the duration, T threshold is the time threshold.

6. The method for monitoring mechanical characteristics of a circuit breaker based on an endoscope and a camera according to claim 5, characterized in that: The current threshold I threshold 0.2A~0.3A, time threshold T threshold It is 3 milliseconds to 4 milliseconds.

7. The method for monitoring mechanical characteristics of a circuit breaker based on an endoscope and a camera according to claim 4, characterized in that: Before the step of extracting and obtaining the mechanical characteristics of the circuit breaker, the step of preprocessing multiple frames of mechanical characteristic images to obtain preprocessed images is included, and the mechanical characteristics of the circuit breaker are extracted from the preprocessed images; the image preprocessing step includes removing noise, adjusting contrast, brightness and correction.

8. The method for monitoring mechanical characteristics of a circuit breaker based on an endoscope and a camera according to claim 4, characterized in that: The step of extracting and obtaining the mechanical characteristics of the circuit breaker includes extracting and obtaining a gradient direction histogram of each frame image, generating a response diagram of each frame image based on the gradient direction histogram, calculating and obtaining a displacement of an operating mechanism of the circuit breaker of each frame image based on the response diagram, and generating a displacement diagram, i.e., the mechanical characteristics of the circuit breaker, based on the displacement of the operating mechanism of the circuit breaker of each frame image.

9. The method for monitoring mechanical characteristics of a circuit breaker based on an endoscope and a camera according to claim 8, characterized in that: In the step of extracting and obtaining the mechanical characteristics of the circuit breaker, the HOG feature extraction of the gradient direction histogram is performed according to formula (2) to obtain the gradient direction histogram of each frame image; HOG=HOG() (2) In formula (2), HOG() is the HOG feature extraction function, and HOG is the gradient direction histogram; Generate the response map of each frame image according to formula (3) based on the gradient direction histogram; R=Response(HOG) (3) In formula (3), Response() is the response graph extraction function, and R is the response graph; Based on the response diagram, the displacement (Δx, Δy) of the operating mechanism of the circuit breaker of each frame image is calculated according to equations (4) and (5); In formula (4), Δx is the horizontal displacement of the target on the operating mechanism; It is used to find the maximum value position in the cross-correlation result, so as to obtain the displacement in the horizontal direction; i is the pixel number in the horizontal direction; M is the maximum pixel number in the horizontal direction; j is the pixel number in the vertical direction; N is the maximum pixel number in the vertical direction; I1(i,j) is the pixel value in the previous response image between two adjacent response images; I2(i,j) is the pixel value in the latter response image between two adjacent response images; a is the horizontal coordinate value corresponding to the maximum pixel value in the two response images; In formula (5), Δy is the vertical displacement of the target on the operating mechanism; argm b ax is used to find the maximum value position in the cross-correlation result, so as to obtain the displacement in the vertical direction; b is the ordinate value corresponding to the maximum pixel value in the two response images.

10. A method for monitoring mechanical characteristics of a circuit breaker based on an endoscope and a camera according to any one of claims 4 to 9, characterized in that: The multi-frame mechanical characteristic images of the operating mechanism are multi-frame mechanical characteristic images of a switch of the operating mechanism.

Images