A Method for Judging the Operating Condition of Disconnecting Switches Based on Echo Transmission Efficiency

Abstract

The present invention relates to a method for discriminating the operating conditions of a disconnector based on the echo transmission efficiency, including: obtaining point cloud data of a target object by using a lidar; analyzing the target object according to the point cloud data to obtain the state of the target object; obtaining the distance between the lidar and the target object; obtaining the surface area of the target object; calculating the echo transmission efficiency of the lidar according to the distance and the surface area; and judging whether the state of the target object is accurate according to the echo transmission efficiency. The present invention uses a lidar to obtain the point cloud data of the disconnector, and performs feature extraction and state judgment based on the point cloud data, having the characteristics of maintaining high-precision monitoring in a low-light environment, being unaffected by the weak light environment, and avoiding the disadvantages of poor performance of the traditional camera monitoring system in a weak light environment.

Description

Technical Field

[0001] The invention relates to a method for distinguishing operating conditions of an isolating switch based on echo transmission efficiency, and belongs to the field of isolating switch monitoring. Background Art

[0002] The high-voltage disconnector is driven by an operating mechanism to drive the moving contact to make contact and separate with the static contact. It is easily affected by the environment when operating outdoors. Transmission jamming, component size changes, and misalignment of transmission components can all cause the disconnector to fail to close properly, resulting in gaps, heat and even discharge, affecting the life of the equipment and threatening the safe operation of the power grid.

[0003] The camera identification system is currently the mainstream means of detecting the opening and closing status of high-voltage disconnectors, but its performance will be significantly reduced at night and in severe weather such as thunderstorms and typhoons; therefore, a high-voltage disconnector visualization monitoring system suitable for nighttime and extreme weather conditions is needed.

[0004] The patent "A Distributed Monitoring Method, System and Medium for Disconnector Status" with publication number CN111199219A discloses the following steps: obtain the disconnector image of the target disconnector; obtain the angle α between the two arms of the disconnector through image analysis; compare the angle α with the calibrated values ​​of the closing and opening states to determine the state of the target disconnector. The invention can accurately monitor the closing and opening states of the target disconnector, but the accuracy of the results is unknown. Summary of the invention

[0005] In order to overcome the problems existing in the prior art, the present invention designs a method for distinguishing the operating condition of an isolating switch based on echo transmission efficiency. A laser radar is used to obtain point cloud data of the isolating switch, and feature extraction and status judgment are performed based on the point cloud data. The method has the characteristics of maintaining high-precision monitoring in low-light environments and is not affected by weak light environments, thus avoiding the disadvantage of poor performance of traditional camera monitoring systems in weak light environments.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] Technical Solution 1

[0008] A method for distinguishing the operating condition of an isolating switch based on echo transmission efficiency comprises the following steps:

[0009] Use LiDAR to obtain point cloud data of the target object;

[0010] Analyze the target object according to the point cloud data to obtain the state of the target object;

[0011] Get the distance between the laser radar and the target object;

[0012] Obtain the surface area of the target object;

[0013] Calculate the echo transmission efficiency of the lidar according to the distance and the surface area;

[0014] Judge whether the state of the target object is accurate according to the echo transmission efficiency.

[0015] Further, the target object is an isolating switch.

[0016] Further, the analyzing the target object based on the point cloud data to obtain the state of the target object includes the following steps:

[0017] Synthesize multiple single-frame point cloud data;

[0018] Use the image target area cropping algorithm to cut the point cloud data to obtain the isolating switch point cloud and the conductive arm point cloud;

[0019] Process the boundary of the conductive arm point cloud with a shrinkage factor in multiple coordinate axis directions;

[0020] Extract the edge of the conductive arm point cloud to obtain the conductive arm point cloud with the characteristic contour of the isolating switch conductive arm;

[0021] Use the clustering algorithm to denoise the conductive arm point cloud;

[0022] Extract the outer edge of the conductive arm from the conductive arm point cloud;

[0023] Delete the interference data of the outer edge point cloud of the conductive arm;

[0024] Perform linear fitting on the outer edge point cloud of the conductive arm, and calculate the conductive arm angle as the state of the target object according to the fitting result.

[0025] Further, it also includes: calculating an error factor according to the state of the target object, which is expressed by the formula:

[0026]

[0027] In the formula, θ m is the calculated value of the conductive arm angle; θ r is the actual value of the conductive arm angle.

[0028] Further, it also includes: if the error factor is less than the preset threshold, it is considered that the state of the target object is accurate; otherwise, it is considered that the state of the target object is inaccurate.

[0029] Further, the calculating the echo transmission efficiency of the lidar is expressed by the formula:

[0030]

[0031] Where η is the echo transmission efficiency of the lidar monitor; F is the laser beam distribution coefficient; θ is the divergence angle; η t is the transmission efficiency of the laser passing through the optical system; η r is the transmission efficiency of the receiving optical system; K p is the diffuse reflection coefficient of the object; S r is the photosensitive area of the lidar receiver; S t is the area of the target object; T is the atmospheric transmittance; L is the distance between the target object and the laser; β is the angle between the incident angle of the lidar and the normal; R is the surface reflectivity of the object; μ is the coefficient related to the radar monitoring distance;

[0032] Further, determining whether the state of the target object is accurate includes the following steps:

[0033] If the echo transmission efficiency is greater than the preset threshold, it is considered that the state of the target object is accurate; otherwise, the detection result is considered inaccurate.

[0034] Technical solution two

[0035] An isolating switch feature discrimination system applicable to low-light environments, comprising:

[0036] A lidar, which is used to obtain the point cloud data of the target object;

[0037] A data processing module, which is used to analyze the target object according to the point cloud data to obtain the state of the target object; calculate the echo transmission efficiency of the lidar according to the distance between the lidar and the target object and the surface area of the target object; and judge whether the state of the target object is accurate according to the echo transmission efficiency.

[0038] Further, the target object is an isolating switch.

[0039] Further, analyzing the target object according to the point cloud data to obtain the state of the target object includes the following steps:

[0040] Synthesize multiple single-frame point cloud data;

[0041] Use the image target area cropping algorithm to cut the point cloud data to obtain the isolating switch point cloud and the conductive arm point cloud;

[0042] In multiple coordinate axis directions, use the shrinkage factor to process the boundary of the conductive arm point cloud;

[0043] Extract the edges of the conductive arm point cloud to obtain the conductive arm point cloud with the characteristic contour of the isolating switch conductive arm;

[0044] Use the clustering algorithm to perform noise reduction processing on the conductive arm point cloud;

[0045] Extract the outer edge of the conductive arm from the point cloud of the conductive arm;

[0046] Delete the interference data of the point cloud on the outer edge of the conductive arm;

[0047] Perform linear fitting on the point cloud of the outer edge of the conductive arm, and calculate the included angle of the conductive arm according to the fitting result as the state of the target object.

[0048] Furthermore, it also includes: calculating an error factor according to the state of the target object, which is expressed by the formula:

[0049]

[0050] In the formula, θ m is the calculated value of the included angle of the conductive arm; θ r is the actual value of the included angle of the conductive arm.

[0051] Furthermore, it also includes: if the error factor is less than the preset threshold, it is considered that the state of the target object is accurate; otherwise, it is considered that the state of the target object is inaccurate.

[0052] Furthermore, calculate the echo transmission efficiency of the lidar, which is expressed by the formula:

[0053]

[0054] In the formula, η is the echo transmission efficiency of the lidar monitor; F is the laser beam distribution coefficient; θ is the divergence angle; η t is the transmission efficiency of the laser passing through the optical system; η r is the transmission efficiency of the receiving optical system; K p is the object diffuse reflection coefficient; S r is the photosensitive area of the lidar receiver; S t is the area of the target object; T is the atmospheric transmittance; L is the distance between the target object and the laser; β is the angle between the lidar incident angle and the normal; R is the surface reflectivity of the object; μ is the coefficient related to the radar monitoring distance;

[0055] Furthermore, judging whether the state of the target object is accurate includes the following steps:

[0056] If the echo transmission efficiency is greater than the preset threshold, it is considered that the state of the target object is accurate; otherwise, it is considered that the detection result is inaccurate.

[0057] Compared with the prior art, the present invention has the following characteristics and beneficial effects:

[0058] The present invention uses a lidar to obtain point cloud data of a disconnector, and performs feature extraction and status judgment based on the point cloud data. It has the characteristics of maintaining high-precision monitoring in low-light environments, being unaffected by weak light environments, and avoiding the disadvantages of poor performance of traditional camera monitoring systems in weak light environments.

[0059] Considering that the measurement distance and the surface area of the object will affect the accuracy of the point cloud data collected by the lidar, thus affecting the accuracy of the target object's state. The present invention calculates the echo transmission efficiency of the lidar according to the distance between the lidar and the disconnector and the surface area of the disconnector, judges the accuracy of the target object's state, and can filter out the point cloud data with unqualified echo intensity, thereby improving the reliability of the target object's state. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 is the flow chart of the present invention;

[0061] Figure 2 is the schematic diagram of the monitoring system described in Embodiment 1. DETAILED DESCRIPTION OF THE INVENTION

[0062] The present invention will be described in more detail below in conjunction with embodiments.

[0063] Embodiment 1

[0064] As Figure 1 shown, a disconnector working condition discrimination system based on echo transmission efficiency includes: a solid-state lidar, a data acquisition module, a point cloud conversion module, a data processing module, a terminal management platform, and an acoustic-optic alarm device.

[0065] The solid-state lidar includes a laser emission device, a laser reception device, and an AC-DC power converter. The solid-state lidar is installed on a support frame near the disconnector, and is arranged upward to monitor the disconnector to obtain the monitoring data of the disconnector.

[0066] The data acquisition module is communicatively connected to the solid-state lidar, and the data acquisition module acquires the monitoring data.

[0067] The point cloud conversion module converts the monitoring data into point cloud data in PCD format that is convenient for processing.

[0068] The data processing module analyzes the target object according to the point cloud data to obtain the state of the target object; calculates the distance between the solid-state lidar and the target object; obtains the surface area of the target object; calculates the echo transmission efficiency of the solid-state lidar according to the distance and the surface area; and judges whether the state of the target object is accurate according to the echo transmission efficiency.

[0069] The terminal management platform includes a terminal interface where users can adjust the parameters of the above-mentioned modules. The terminal interface displays the original image of the disconnector and the processing results of the point cloud data in real time, realizing process automation.

[0070] In this embodiment, the state of the target object is the opening and closing angle of the disconnector. When the calculated opening and closing angle of the disconnector is not equal to the specified value, an alarm signal is sent using the acoustic-optic alarm device.

[0071] Embodiment 2

[0072] A method for calculating echo power applicable to low-light environments includes the following steps:

[0073] Affected by the surface reflectivity of the object, the atmospheric transmittance, and the distance between the monitoring device and the object, the calculation formula for the echo transmission efficiency η of the lidar system is as follows:

[0074]

[0075] In the formula, η is the echo transmission efficiency of the lidar monitor; F is the laser beam distribution coefficient; θ is the divergence angle; η t is the transmission efficiency of the laser through the optical system; η r is the transmission efficiency of the receiving optical system of the lidar; K p is the diffuse reflection coefficient of the object; S r is the photosensitive area of the lidar receiver; S t is the area of the target object; T is the atmospheric transmittance; L is the distance between the target object and the laser; β is the angle between the lidar incident angle and the normal; R is the surface reflectivity of the object; μ is a coefficient related to the radar monitoring distance;

[0076] When η ≥ 65%, it is considered that the lidar detection accuracy is good and the data is credible; when η ≤ 65%, it is considered that the lidar detection accuracy is low, and monitoring devices such as the lidar need to be adjusted.

[0077] Embodiment 3

[0078] Analyze the disconnector based on the point cloud data to obtain the state of the target object, including feature extraction and state judgment of the disconnector. The specific steps are as follows:

[0079] Step 3-1: Use the software CloudCompare to select multiple single-frame PCD data from the disconnector point cloud data collected in the same time period for synthesis to increase the amount of point cloud data, improve the image imaging effect, be more conducive to the extraction of the disconnector conductive arm features, and enhance data reliability;

[0080] Step 3-2: Perform point cloud projection in data processing software to improve analysis efficiency; use the image target area cropping algorithm to perform two-point cloud cuts to obtain the overall point cloud of the disconnector and the point cloud of the conductive arm; introduce shrinkage factors S x 、S y 、S z in the x, y, and z-axis directions respectively; change the values of the shrinkage factors to make the conductive arm of the disconnector in the point cloud data have the best tightened boundary effect;

[0081] Step 3-3: Use the edge extraction algorithm to perform boundary extraction on the point cloud of the conductive arm to obtain the point cloud of the conductive arm with a clear feature contour of the disconnector conductive arm;

[0082] Step 3-4: Use the Euclidean clustering algorithm to perform noise reduction on the point cloud of the conductive arm to obtain multiple Euclidean clustering files of the point cloud of the conductive arm to reduce environmental background noise; call the Euclidean clustering file that can display the disconnector features to achieve the extraction of the outer edge of the conductive arm; among them, set the value range of the clustering threshold coefficient k of the Euclidean clustering algorithm within the interval [0.03, 0.12];

[0083] Step 3-5: Perform further point cloud cutting on the called Euclidean clustering file to delete interference data such as the front contact of the outer edge of the conductive arm;

[0084] Step 3-6: Perform linear fitting on the outer edge point cloud of the conductive arm and calculate the included angle of the conductive arm according to the fitting result as the state of the target object.

[0085] Example 4

[0086] Furthermore, calculate the error factor according to the state of the target object. If the error factor is less than the preset threshold, it is considered that the state of the target object is accurate; otherwise, it is considered that the state of the target object is inaccurate.

[0087] The calculation formula of the factor is as follows:

[0088]

[0089] In the formula, θ m is the calculated value of the included angle of the conductive arm; θ r is the actual value of the included angle of the conductive arm.

[0090] According to the actual working condition requirements, when α < 0.5%, it means that the state of the target object has reliability; after testing, this measurement method can achieve α < 0.2% in various working conditions.

[0091] It should be noted that the above-mentioned disconnector working condition discrimination system and computer-readable storage medium based on echo transmission efficiency are also used to implement the above-mentioned Figure 1The method steps corresponding to the embodiments in a method for discriminating the operating conditions of a disconnector based on echo transmission efficiency shown are not repeated herein in this application.

[0092] It should be noted that in each embodiment of the present invention, each functional unit / module can be integrated in a processing unit / module, or each unit / module can exist physically alone, or two or more units / module can be integrated in one unit / module. The above integrated unit / module can be implemented in the form of hardware or in the form of a software functional unit / module.

[0093] Through the description of the above embodiments, those skilled in the art can clearly understand and should understand that the embodiments described herein can be implemented by hardware, software, firmware, middleware, code, or any appropriate combination thereof. For hardware implementation, the processor can be implemented in one or more of the following units: application specific integrated circuit (ASIC), digital signal processor (DSP), digital signal processing device (DSPD), programmable logic device (PLD), field programmable gate array (FPGA), processor, controller, microcontroller, microprocessor, other electronic units designed to implement the functions described herein, or a combination thereof. For software implementation, part or all of the processes of the embodiments can be completed by instructing relevant hardware through a computer program. When implemented, the above program can be stored in a computer-readable medium or transmitted as one or more instructions or codes on a computer-readable medium. The computer-readable medium includes computer storage media and communication media, where the communication media includes any medium facilitating the transmission of a computer program from one place to another. The storage media can be any available medium accessible by a computer. The computer-readable medium can include, but is not limited to, RAM, ROM, EEPROM, CD-ROM, or other optical disc storage, magnetic disk storage media, or other magnetic storage devices, or any other medium capable of carrying or storing the desired program code in the form of instructions or data structures and accessible by a computer.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should analyze that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for discriminating the operating conditions of a disconnector based on the echo transmission efficiency, characterized in that It includes the following steps: Obtain the point cloud data of the target object using a lidar; Analyze the target object based on the point cloud data to obtain the state of the target object; Obtain the distance between the lidar and the target object; Obtain the surface area of the target object; Calculate the echo transmission efficiency of the lidar according to the distance and the surface area; The calculation of the echo transmission efficiency of the lidar is expressed by the formula: Where η is the echo transmission efficiency of the lidar monitor; F is the laser beam distribution coefficient; θ is the divergence angle; η t is the transmission efficiency of the laser passing through the optical system; η r is the transmission efficiency of the receiving optical system; K p is the diffuse reflection coefficient of the object; S r is the photosensitive area of the lidar receiver; S t is the area of the target object; T is the atmospheric transmittance; L is the distance between the target object and the laser; β is the angle between the lidar incident angle and the normal; R is the surface reflectivity of the object; μ is the coefficient related to the radar monitoring distance; Judge whether the state of the target object is accurate according to the echo transmission efficiency.

2. The method for discriminating the operating conditions of a disconnector based on the echo transmission efficiency according to claim 1, wherein The judgment of whether the state of the target object is accurate includes the following steps: If the echo transmission efficiency is greater than the preset threshold, it is considered that the state of the target object is accurate; otherwise, the detection result is considered inaccurate.

3. An isolating switch feature discrimination system applicable to low-light environments, characterized in that, It includes: A lidar, which is used to obtain the point cloud data of the target object; A data processing module, which is used to analyze the target object according to the point cloud data to obtain the state of the target object; calculate the echo transmission efficiency of the lidar according to the distance between the lidar and the target object and the surface area of the target object; Judge whether the state of the target object is accurate according to the echo transmission efficiency; Among them, the calculation of the echo transmission efficiency of the lidar is expressed by the formula: Where η is the echo transmission efficiency of the lidar monitor; F is the laser beam distribution coefficient; θ is the divergence angle; η t is the transmission efficiency of the laser passing through the optical system; η r is the transmission efficiency of the receiving optical system; K p is the object diffuse reflection coefficient; S r is the photosensitive area of the lidar receiver; S t is the target object area; T is the atmospheric transmittance; L is the distance between the target object and the laser; β is the angle between the lidar incident angle and the normal; R is the surface reflectivity of the object; μ is the coefficient related to the radar monitoring distance.

4. The isolation switch feature discrimination system applicable to low-light environments according to claim 3, wherein The target object is a disconnecting switch.

5. A method for discriminating the operating conditions of a disconnector based on the echo transmission efficiency, characterized in that, It includes the following steps: Obtain the point cloud data of the target object using a lidar; Analyze the target object based on the point cloud data to obtain the state of the target object; Calculate the error factor according to the state of the target object. If the error factor is less than the preset threshold, it is considered that the state of the target object is accurate; Otherwise, it is considered that the state of the target object is inaccurate.

6. The method for discriminating the operating condition of a disconnector based on the echo transmission efficiency according to claim 5, characterized in that, The target object is a disconnecting switch.

7. A method for discriminating the operating condition of a disconnector based on the echo transmission efficiency according to claim 6, characterized in that, The analysis of the target object based on the point cloud data to obtain the state of the target object includes the following steps: Synthesize multiple single-frame point cloud data; Use the image target area cropping algorithm to cut the point cloud data to obtain the conductive arm point cloud; Process the boundary of the conductive arm point cloud in multiple coordinate axis directions using a shrinkage factor; Perform edge extraction on the conductive arm point cloud to obtain the conductive arm point cloud with the characteristic contour of the disconnecting switch conductive arm; Use the clustering algorithm to perform noise reduction processing on the conductive arm point cloud; Perform outer edge extraction on the conductive arm point cloud; Delete the interference data of the outer edge point cloud of the conductive arm; Perform linear fitting on the outer edge point cloud of the conductive arm, and calculate the conductive arm angle according to the fitting result as the state of the target object.

8. A method for discriminating the operating conditions of a disconnector based on the echo transmission efficiency according to claim 7, characterized in that, It also includes: Calculate the error factor according to the state of the target object, which is expressed by the formula: In the formula, θ m is the calculated value of the included angle of the conductive arm; θ r is the actual value of the included angle of the conductive arm.

9. A computer-readable storage medium, characterized in that, The storage medium stores a computer program, and the computer program is used to execute a method for discriminating the operating condition of a disconnecting switch based on echo transmission efficiency as described in any one of claims 1-2, 5-8 above.

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