CN113222965B - Three-dimensional observation method for discharge channel - Google Patents
Three-dimensional observation method for discharge channel Download PDFInfo
- Publication number
- CN113222965B CN113222965B CN202110588074.1A CN202110588074A CN113222965B CN 113222965 B CN113222965 B CN 113222965B CN 202110588074 A CN202110588074 A CN 202110588074A CN 113222965 B CN113222965 B CN 113222965B
- Authority
- CN
- China
- Prior art keywords
- discharge channel
- discharge
- dimensional
- point cloud
- point
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 46
- 238000001914 filtration Methods 0.000 claims abstract description 55
- 238000003384 imaging method Methods 0.000 claims abstract description 28
- 230000001360 synchronised effect Effects 0.000 claims description 10
- 238000012937 correction Methods 0.000 claims description 7
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 5
- 238000004364 calculation method Methods 0.000 claims description 5
- 239000011159 matrix material Substances 0.000 claims description 4
- 230000009466 transformation Effects 0.000 claims description 4
- 238000005259 measurement Methods 0.000 claims description 3
- 230000001419 dependent effect Effects 0.000 claims 1
- 208000028659 discharge Diseases 0.000 description 119
- 108091006146 Channels Proteins 0.000 description 102
- 238000011045 prefiltration Methods 0.000 description 3
- 230000011514 reflex Effects 0.000 description 3
- 101000694017 Homo sapiens Sodium channel protein type 5 subunit alpha Proteins 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 239000003086 colorant Substances 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 206010034960 Photophobia Diseases 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 208000013469 light sensitivity Diseases 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 238000012800 visualization Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T7/00—Image analysis
- G06T7/0002—Inspection of images, e.g. flaw detection
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F18/00—Pattern recognition
- G06F18/20—Analysing
- G06F18/22—Matching criteria, e.g. proximity measures
-
- G06T5/70—
-
- G06T5/80—
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T7/00—Image analysis
- G06T7/80—Analysis of captured images to determine intrinsic or extrinsic camera parameters, i.e. camera calibration
- G06T7/85—Stereo camera calibration
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T7/00—Image analysis
- G06T7/90—Determination of colour characteristics
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T2207/00—Indexing scheme for image analysis or image enhancement
- G06T2207/10—Image acquisition modality
- G06T2207/10028—Range image; Depth image; 3D point clouds
Abstract
The method comprises the steps of constructing a binocular stereo imaging system, carrying out three-dimensional reconstruction of a discharge channel by utilizing binocular imaging, obtaining point coordinates of the discharge channel by a point cloud before filtering, generating the point cloud of the discharge channel by filtering noise data in the point cloud before filtering based on a point cloud filtering algorithm, and drawing the point cloud of the discharge channel in a three-dimensional coordinate system to obtain a three-dimensional image of the discharge channel; and extracting physical quantities of the discharge channels based on the three-dimensional images of the discharge channels, wherein the physical quantities comprise the actual lengths of the discharge channels and the actual angles between the channels.
Description
Technical Field
The invention relates to the technical field of high-voltage testing, in particular to a three-dimensional observation method of a discharge channel.
Background
When the field intensity in the dielectric medium exceeds a certain value, a discharge channel is formed inside; the accurate observation of the discharge channel is helpful for understanding the discharge process, and has important significance for grasping the discharge physics. For example, the development of discharge channels in air or other electronegative gaseous media is often accompanied by a "streamer-leader" transition, exhibiting a leader stepping pattern; the length, angle and speed of the pilot step are important parameters of the gas discharge physics.
At present, a two-dimensional image observation is mainly carried out by using a camera in an observation means of a discharge channel. The discharge channel in three-dimensional space is a space curve in three-dimensional space, and only a two-dimensional projection thereof on an observation plane can be obtained using two-dimensional image observation. Therefore, the channel length, the channel angle, the channel development speed and the like extracted from the two-dimensional image can not truly reflect the real properties of the discharge channel in the three-dimensional space.
Over the last three decades, many efforts have been made by students to obtain a true trajectory of the discharge channel in three dimensions. J.m.k.macalpine and m.makarov et al use a camera and prism to capture orthogonal images of the discharge channel, reconstructing the spark path, but the method is only applicable to situations where the discharge channel has no crossover and fewer branches. The three-dimensional image of the flow channel in the air is observed by Nijdam et al by using a binocular imaging method, and the reconstruction work is completed manually only to obtain rough distribution of the channel because the research thereof assumes that the camera is far away from the discharge and the focal length is large. Therefore, a three-dimensional observation method of the discharge channel is still lacking at present, and the real track of the discharge channel in the three-dimensional space can be accurately extracted.
In view of the above, it is necessary to provide a three-dimensional observation method of the discharge channel to help researchers develop intensive research work on the physical mechanism of discharge.
The above information disclosed in the background section is only for enhancement of understanding of the background of the invention and therefore may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.
Disclosure of Invention
The invention aims to provide a three-dimensional observation method of a discharge channel. And accurately extracting the real track of the discharge channel in the three-dimensional space by a binocular imaging method. In order to achieve the above object, the present invention provides the following technical solutions:
the three-dimensional observation method of the discharge channel comprises the following steps:
the first step, a binocular stereo imaging system is built,
a second step of performing three-dimensional reconstruction of the discharge channel by binocular imaging, obtaining a point cloud before filtering to obtain the point coordinates of the discharge channel,
a third step of generating a discharge channel point cloud based on noise data in the point cloud before filtering filtered by a point cloud filtering algorithm,
drawing the discharge channel point cloud in a three-dimensional coordinate system to obtain a discharge channel three-dimensional image;
and a fifth step of extracting physical quantities of the discharge channels based on the three-dimensional images of the discharge channels, the physical quantities including actual lengths of the discharge channels and actual angles between the channels.
In the first step, the binocular stereoscopic imaging system comprises two identical cameras which are focused to a discharge area and are placed in a darkroom, and the two cameras are connected by using a synchronous shutter connecting wire to ensure synchronous shooting.
In the three-dimensional observation method of the discharge channel, in the first step, a binocular three-dimensional imaging system shoots calibration pictures, and after a calibration plate printed with a checkerboard is put into a field of view of cameras, each camera shoots a plurality of calibration pictures; and calibrating the camera to obtain camera parameters after detecting the checkerboard coordinates in the calibration picture based on the calibration picture and the grid side length of the calibration plate.
In the second step, a binocular stereoscopic imaging system shoots a discharge image, and homography matrix transformation is carried out on the discharge image according to the camera parameters to obtain a stereoscopic corrected picture; drawing the picture after the three-dimensional correction in a red-blue chart, measuring the parallax distance between the nodes of the discharge channel, wherein the maximum parallax obtained by measurement is a parallax range, and carrying out parallax calculation on all points of the picture after the three-dimensional correction according to the matching cost based on the parallax range to obtain the parallax chart.
In the second step, a point cloud before filtering is generated based on the camera parameters and the parallax map so as to obtain the point coordinates of the discharge channel in a world coordinate system.
In the third step, the point cloud filtering algorithm simultaneously uses a straight-through filtering algorithm and a filtering algorithm according to colors, wherein the straight-through filtering algorithm determines the range of a discharge area in the x direction, the y direction or the z direction so as to filter the point cloud outside the discharge area, and the filtering algorithm according to the colors judges whether the discharge is the discharge channel or not based on the noise lighting degree.
In the three-dimensional observation method of a discharge channel, the filtering algorithm step according to the color comprises the following steps: and traversing the point cloud before filtering, wherein the maximum value of the R component, the G component or the B component of the coordinate color of the point is smaller than a brightness threshold value, and the point is a noise point.
In the three-dimensional observation method of the discharge channel, the brightness threshold is 15.
In the third step, a pcshow function is adopted to obtain a three-dimensional image of the discharge channel based on the point cloud of the discharge channel.
In the three-dimensional observation method of the discharge channel, the calibration plate is an alumina calibration plate, and the grid side length is 3mm.
In the technical scheme, the three-dimensional observation method for the discharge channel provided by the invention has the following beneficial effects: according to the invention, the three-dimensional image of the discharge channel is automatically acquired by a machine vision method, and the long-focus lens is used for focusing on the discharge region, so that the accurate partial discharge three-dimensional channel is obtained, and the observation efficiency and accuracy are remarkably improved.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments described in the present invention, and other drawings may be obtained according to these drawings for a person having ordinary skill in the art.
FIG. 1 is a schematic diagram of a three-dimensional observation method data flow of a discharge channel in the invention;
FIG. 2 shows a method for arranging an imaging system in a first step of a three-dimensional observation method of a discharge channel in the present invention;
fig. 3 is an example of a three-dimensional image of a discharge channel obtained by the three-dimensional observation method of a discharge channel in the present invention.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to fig. 1 to 3 of the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. All other embodiments, based on the embodiments of the invention, which are apparent to those of ordinary skill in the art without inventive faculty, are intended to be within the scope of the invention.
Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, based on the embodiments of the invention, which are apparent to those of ordinary skill in the art without inventive faculty, are intended to be within the scope of the invention.
It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.
In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.
In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.
In the present invention, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.
In order to make the technical scheme of the present invention better understood by those skilled in the art, the present invention will be further described in detail with reference to the accompanying drawings. As shown in fig. 1 to 3, a three-dimensional observation method of a discharge channel includes,
the first step, a binocular stereo imaging system is built,
a second step of performing three-dimensional reconstruction of the discharge channel by binocular imaging, obtaining a point cloud before filtering to obtain the point coordinates of the discharge channel,
a third step of generating a discharge channel point cloud based on noise data in the point cloud before filtering filtered by a point cloud filtering algorithm,
drawing the discharge channel point cloud in a three-dimensional coordinate system to obtain a discharge channel three-dimensional image;
and a fifth step of extracting physical quantities of the discharge channels based on the three-dimensional images of the discharge channels, the physical quantities including actual lengths of the discharge channels and actual angles between the channels.
In a preferred embodiment of the three-dimensional observation method for a discharge channel, in the first step, the binocular stereoscopic imaging system includes two identical cameras 1, 2 focused to the discharge area 3, which are placed in the dark room, and the two cameras 1, 2 are connected using a synchronous shutter connection line to ensure synchronous shooting.
In the preferred implementation mode of the three-dimensional observation method of the discharge channel, in the first step, a binocular three-dimensional imaging system shoots calibration pictures, and after a calibration plate printed with a checkerboard is put into the fields of vision of cameras 1 and 2, each camera shoots a plurality of calibration pictures; and calibrating the cameras 1 and 2 to obtain camera parameters after detecting the checkerboard coordinates in the calibration picture based on the calibration picture and the grid side length of the calibration plate.
In the second step, a binocular stereoscopic imaging system shoots a discharge image, and homography matrix transformation is carried out on the discharge image according to the camera parameters to obtain a stereoscopic corrected picture; drawing the picture after the three-dimensional correction in a red-blue chart, measuring the parallax distance between the nodes of the discharge channel, wherein the maximum parallax obtained by measurement is a parallax range, and carrying out parallax calculation on all points of the picture after the three-dimensional correction according to the matching cost based on the parallax range to obtain the parallax chart.
In a preferred embodiment of the three-dimensional observation method for a discharge channel, in the second step, a filtered front point cloud is generated based on the camera parameters and the disparity map, so as to obtain point coordinates of the discharge channel in a world coordinate system.
In the third step, the point cloud filtering algorithm uses both a straight-through filtering algorithm and a color-based filtering algorithm, wherein the straight-through filtering algorithm determines the range of the discharge area 3 in the x or y or z direction to filter the point cloud outside the discharge area 3, and the color-based filtering algorithm judges whether the discharge is a discharge channel based on the noise lighting degree.
In a preferred embodiment of the three-dimensional observation method for a discharge channel, the filtering algorithm step according to color includes: and traversing the point cloud before filtering, wherein the maximum value of the R component, the G component or the B component of the coordinate color of the point is smaller than a brightness threshold value, and the point is a noise point.
In a preferred embodiment of the three-dimensional observation method for a discharge channel, the brightness threshold is 15.
In a preferred embodiment of the three-dimensional observation method for a discharge channel, in the fourth step, a pcshow function is used to obtain a three-dimensional image of the discharge channel based on the point cloud of the discharge channel.
In a preferred embodiment of the three-dimensional observation method for a discharge channel, the calibration plate is an alumina calibration plate, and the grid side length of the calibration plate is 3mm.
In a preferred embodiment of the three-dimensional observation method for a discharge channel, the discharge channel is approximated to a space vector of each section of straight line channel by a plurality of connected line segments, and three-dimensional coordinates of channel endpoints are obtained by selecting line segment nodes.
In a preferred embodiment of the three-dimensional observation method for a discharge channel, the actual length of the discharge channel and the actual angle of the discharge channel are obtained according to a calculation formula of a vector mode and an included angle respectively.
In one embodiment, a three-dimensional observation method of a discharge channel includes the steps of:
in the first step, a binocular stereo imaging system is built, and the cameras 1 and 2 are preferably single-lens reflex cameras or ICCD cameras with high light sensitivity. The two cameras 1, 2 should be well synchronized, if a single phase inverter is used, a synchronous shutter connecting line can be used; if an ICCD camera is used, trigger signals of the two cameras should be sent out synchronously. The lens is a long-focus lens, has long focal length and small imaging range, can be focused on the discharge area 3 and is used for observing a discharge channel. The built binocular stereoscopic imaging system comprises two cameras 1 and 2 with the same model and two lenses with the same parameters.
And a second step of performing three-dimensional reconstruction by using a binocular imaging technology to obtain a point cloud before filtering, namely, the point coordinates of the discharge channel in a world coordinate system.
And thirdly, filtering noise data contained in the point cloud before filtering in the fourth step by using a point cloud filtering algorithm. The purpose of this step is to filter out noise data contained in the pre-filter point cloud described in the fourth step. Conventional point cloud filtering algorithms include, but are not limited to, straight-through filtering algorithms, conditional filtering algorithms, gaussian filtering algorithms, and the like. Because the discharge channel is brighter and has color information which is distinct from the background, a color-based filtering algorithm is proposed, wherein the color-based filtering algorithm judges whether the discharge is a discharge channel by utilizing the characteristic that the noise brightness is far lower than the brightness of the discharge channel, and the algorithm comprises the following steps: and traversing the point cloud before filtering, and if the maximum value of the R component, the G component or the B component of the coordinate color of the point is smaller than the brightness threshold value, determining the point as a noise point. The brightness threshold is preferably a value between 5 and 20. The output of the step is the filtered discharge channel point cloud. The straight-through filtering algorithm is preferably realized by adopting a findPointsInROI function in Matlab software.
And fourthly, drawing the discharge channel point cloud in the fifth step in a three-dimensional coordinate system to obtain a three-dimensional image of the discharge channel. This step is preferably implemented using the pcshow function in Matlab software.
And a fifth step of extracting key physical quantities of the discharge channels from the three-dimensional image of the discharge channels described in the sixth step, including but not limited to the actual lengths of the channels, the actual angles between the channels, and the like.
As shown in fig. 1, this example is a discharge channel for observing pre-discharge in a highly non-uniform electric field in an SF6/N2 gas atmosphere using the method described in the present patent.
The steps in this embodiment may be implemented by using software including, but not limited to, matlab, opencv, PCL, etc., and other methods are also included in the scope of the present invention.
The three-dimensional observation method of the discharge channel includes,
in a first step, an imaging system is arranged. The imaging system comprises two cameras 1 and 2 with the same model and two lenses with the same parameters. The imaging system should be placed in a dark room to prevent ambient light from entering. The two cameras 1, 2 need to be separated by a certain distance and focused accurately to the discharge area 3. In this embodiment, the cameras 1, 2 are single-lens reflex cameras of the model Nikon D5. The lens adopts a long-focus lens with the focal length of 200 mm. The two single-lens reflex cameras are connected by using a synchronous shutter connecting wire so as to ensure synchronous shooting.
And a second step of taking a calibration picture (201). And after the calibration plate printed with the checkerboard is placed in the field of view of the cameras, 20 pictures are shot by each camera. The calibration plate is preferably a high-precision opaque, non-reflective alumina calibration plate. In the embodiment, the calibration plate is an alumina calibration plate with a lattice side length of 3mm and a model number of GP 050.
And thirdly, calibrating camera parameters. And inputting a calibration picture (201) and the grid side length of the calibration plate, and calibrating the camera after detecting the checkerboard coordinates in the calibration picture (201) to obtain camera parameters (203). The sign of this step completion is that the re-projection error of the calibration result is less than 0.5 pixels and the camera position coincides with the actual camera position. The calibration method adopts Zhang Zhengyou calibration method. The camera calibration is realized by adopting a dual-target tool box stereoCameraCalif. in Matlab software.
And a fourth step of photographing a discharge image. A discharge image is captured (202) using the aforementioned imaging system. The discharge image (202) should have a sufficient signal-to-noise ratio and pixel accuracy. In the shooting, a higher sensitivity is selected for shooting, and in the embodiment, the camera sensitivity is set to be ISO-102400.
And fifthly, correcting the three-dimensional correction. Since it is difficult to ensure coplanarity of the camera and the optical center level, it is necessary to perform homography matrix transformation on the photographed image according to the camera parameters (203). The purpose of this step is to re-project the planes of the two differently directed discharge images (202) to the same plane with the optical axes parallel to each other. The discharge image (202) described in the fourth step is input and output as a stereoscopic corrected picture (204). The stereo corrected picture (204) has the feature that the image planes are coplanar and the projections of the target object in the two images have the same abscissa. The step is implemented by adopting a rectifyStereoImages function in Matlab software.
Sixth, the parallax range is read (205). The specific method of the step is to draw the stereo corrected image (204) in the red-blue chart and measure the parallax distance between the key nodes of the discharge channel. The maximum parallax obtained is measured (205), i.e. the parallax range. The step is realized by adopting a stereoAnaglyph function in Matlab software.
And seventhly, stereo matching. The purpose of this step is to perform parallax computation on all points of the whole image according to the matching cost. In this embodiment, the algorithm adopted in this step is a Semi-Global Matching (SGM) algorithm. This step requires inputting the stereoscopic corrected picture (204) and the parallax range (205) described in the sixth step, and outputting it as a parallax map (206). In this embodiment, gradation processing is performed on the stereoscopic corrected picture. The uniqueness threshold parameter of the SGM algorithm is set to 15 in this embodiment. The step is realized by adopting a disparitySGM function in Matlab software.
And eighth step, three-dimensional reconstruction. The purpose of this step is to obtain the point coordinates of the discharge channel in the world coordinate system. The input is the camera calibration parameters obtained in the third step and the parallax map (206) described in the seventh step, and the output is the point cloud (207) before filtering. The step is realized by adopting a reconstructScene function in Matlab software.
And ninth step, point cloud filtering. The purpose of this step is to filter out noise data contained in the pre-filter point cloud (207) described in the eighth step. In this embodiment, the point cloud filtering algorithm uses both a pass filtering algorithm and a color-based filtering algorithm. The straight-through filtering algorithm is used for determining the range of the discharge area 3 in the x direction, the y direction or the z direction, so that point clouds outside the discharge area 3 are filtered. The filtering algorithm according to the color judges whether the discharge is a discharge channel by utilizing the characteristic that the brightness of a noise point is far lower than that of the discharge channel, and the algorithm comprises the following steps: traversing the pre-filter point cloud (207), and if the maximum value of the point coordinate color R component or G component or B component is less than the brightness threshold, the point is a noise point. In this embodiment, the brightness threshold is preferably 15. The step output is a filtered discharge channel point cloud (208). The straight-through filtering algorithm is realized by adopting a findPointsInROI function in Matlab software.
And tenth step, point cloud visualization. The purpose of this step is to draw the discharge channel point cloud (208) described in the ninth step into a three-dimensional coordinate system, and obtain a discharge channel three-dimensional image (209). The step is realized by adopting a pcshow function in Matlab software.
And eleventh, extracting key physical quantity. The purpose of this step is to extract key physical quantities of the discharge channel, including but not limited to channel length, channel angle, etc., from the three-dimensional image (209) of the discharge channel described in the tenth step.
Finally, it should be noted that: the described embodiments are intended to be illustrative of only some, but not all, of the embodiments disclosed herein and, based on the embodiments disclosed herein, all other embodiments that may be made by those skilled in the art without the benefit of the teachings herein are intended to be within the scope of this application.
While certain exemplary embodiments of the present invention have been described above by way of illustration only, it will be apparent to those of ordinary skill in the art that modifications may be made to the described embodiments in various different ways without departing from the spirit and scope of the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive of the scope of the invention, which is defined by the appended claims.
Claims (8)
1. A three-dimensional observation method of a discharge channel, characterized by comprising the steps of:
the method comprises the steps that a binocular three-dimensional imaging system is built, the binocular three-dimensional imaging system comprises two identical cameras which are focused to a discharge area and are placed in a darkroom, the two cameras are connected through a synchronous shutter connecting wire to ensure synchronous shooting, the binocular three-dimensional imaging system shoots calibration pictures, and after a calibration plate printed with a checkerboard is placed in a camera field of view, each camera shoots a plurality of calibration pictures; detecting the checkerboard coordinates in the calibration picture based on the calibration picture and the grid side length of the calibration plate, calibrating the camera to obtain camera parameters,
a second step of performing three-dimensional reconstruction of the discharge channel by binocular imaging, obtaining a point cloud before filtering to obtain the point coordinates of the discharge channel,
a third step of generating a discharge channel point cloud based on noise data in the point cloud before filtering filtered by a point cloud filtering algorithm,
drawing the discharge channel point cloud in a three-dimensional coordinate system to obtain a discharge channel three-dimensional image;
and fifthly, extracting physical quantities of the discharge channel based on the three-dimensional image of the discharge channel, wherein the physical quantities comprise the actual length of the discharge channel and the actual angle between the channels, and respectively obtaining the actual length of the discharge channel and the actual angle of the discharge channel according to a calculation formula of a vector mode and an included angle.
2. The three-dimensional observation method of a discharge channel according to claim 1, wherein in the second step, a binocular stereoscopic imaging system shoots a discharge image, and homography matrix transformation is performed on the discharge image according to the camera parameters to obtain a stereoscopic corrected picture; drawing the picture after the three-dimensional correction in a red-blue chart, measuring the parallax distance between the nodes of the discharge channel, wherein the maximum parallax obtained by measurement is a parallax range, and carrying out parallax calculation on all points of the picture after the three-dimensional correction according to the matching cost based on the parallax range to obtain the parallax chart.
3. The method according to claim 2, wherein in the second step, a filtered point cloud is generated based on the camera parameters and the disparity map to obtain the point coordinates of the discharge channel in the world coordinate system.
4. A three-dimensional observation method for a discharge channel according to claim 3, wherein in the third step, a point cloud filtering algorithm uses both a through filtering algorithm and a color-based filtering algorithm, the through filtering algorithm determines a range of a discharge region in an x-direction, a y-direction or a z-direction to filter out point clouds outside the discharge region, and the color-based filtering algorithm determines whether the discharge is the discharge channel based on noise lighting.
5. The method of three-dimensional observation of a discharge channel according to claim 4, wherein said color-dependent filtering algorithm step comprises: and traversing the point cloud before filtering, wherein the maximum value of the R component, the G component or the B component of the coordinate color of the point is smaller than a brightness threshold value, and the point is a noise point.
6. The method of claim 5, wherein the brightness threshold is 15.
7. The method according to claim 5, wherein in the fourth step, a pcshow function is used to obtain a three-dimensional image of the discharge channel based on the point cloud of the discharge channel.
8. The method according to claim 1, wherein the calibration plate is an alumina calibration plate having a lattice side length of 3mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110588074.1A CN113222965B (en) | 2021-05-27 | 2021-05-27 | Three-dimensional observation method for discharge channel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110588074.1A CN113222965B (en) | 2021-05-27 | 2021-05-27 | Three-dimensional observation method for discharge channel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113222965A CN113222965A (en) | 2021-08-06 |
| CN113222965B true CN113222965B (en) | 2023-12-29 |
Family
ID=77099702
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110588074.1A Active CN113222965B (en) | 2021-05-27 | 2021-05-27 | Three-dimensional observation method for discharge channel |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113222965B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103149458A (en) * | 2012-11-21 | 2013-06-12 | 华中科技大学 | Lightning monitoring equipment |
| WO2015024407A1 (en) * | 2013-08-19 | 2015-02-26 | 国家电网公司 | Power robot based binocular vision navigation system and method based on |
| CN110992463A (en) * | 2019-11-11 | 2020-04-10 | 国网通用航空有限公司 | Three-dimensional reconstruction method and system for sag of power transmission conductor based on trinocular vision |
| CN111750806A (en) * | 2020-07-20 | 2020-10-09 | 西安交通大学 | Multi-view three-dimensional measurement system and method |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105719284B (en) * | 2016-01-18 | 2018-11-06 | 腾讯科技（深圳）有限公司 | A kind of data processing method, device and terminal |
-
2021
- 2021-05-27 CN CN202110588074.1A patent/CN113222965B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103149458A (en) * | 2012-11-21 | 2013-06-12 | 华中科技大学 | Lightning monitoring equipment |
| WO2015024407A1 (en) * | 2013-08-19 | 2015-02-26 | 国家电网公司 | Power robot based binocular vision navigation system and method based on |
| CN110992463A (en) * | 2019-11-11 | 2020-04-10 | 国网通用航空有限公司 | Three-dimensional reconstruction method and system for sag of power transmission conductor based on trinocular vision |
| CN111750806A (en) * | 2020-07-20 | 2020-10-09 | 西安交通大学 | Multi-view three-dimensional measurement system and method |
Non-Patent Citations (3)
| Title |
|---|
| Stereo-photography of point-plane streamers in air;S Nijdam etal.;http://arXiv:0802.3639v1;全文 * |
| 氩气环境中铝单丝电爆炸空间形态演化特性;刘浩宇等;中国电机工程学报;第40卷(第10期);全文 * |
| 高压开关柜局部放电检测机器人的开发与应用;栾贻青等;《中国电力》;20190331;第52卷(第03期);第3.3节第3段 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113222965A (en) | 2021-08-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105160680B (en) | A kind of design method of the noiseless depth camera based on structure light | |
| CN107025670A (en) | A kind of telecentricity camera calibration method | |
| KR20190076998A (en) | Apparatus and method for obtaining distance information from a view | |
| CN109813251A (en) | Method, apparatus and system for three-dimensional measurement | |
| CN108020175B (en) | multi-grating projection binocular vision tongue surface three-dimensional integral imaging method | |
| US20120134537A1 (en) | System and method for extracting three-dimensional coordinates | |
| CN112150528A (en) | Depth image acquisition method, terminal and computer readable storage medium | |
| CN109443245B (en) | Multi-line structured light vision measurement method based on homography matrix | |
| CN112525107B (en) | Structured light three-dimensional measurement method based on event camera | |
| CN105378794A (en) | 3d recording device, method for producing 3d image, and method for setting up 3d recording device | |
| CN113592721B (en) | Photogrammetry method, apparatus, device and storage medium | |
| CN109727290A (en) | Zoom camera dynamic calibrating method based on monocular vision triangle telemetry | |
| CN110763140B (en) | Non-parallel optical axis high-precision binocular ranging method | |
| CN112595263A (en) | Binocular vision three-dimensional point cloud reconstruction measuring method for sinusoidal grating and speckle mixed pattern projection | |
| CN109091099A (en) | The high definition miniature electronic endoscopic system of binocular vision | |
| CN116222425A (en) | Three-dimensional reconstruction method and system based on multi-view three-dimensional scanning device | |
| CN114359406A (en) | Calibration of auto-focusing binocular camera, 3D vision and depth point cloud calculation method | |
| CN110378995A (en) | A method of three-dimensional space modeling is carried out using projection feature | |
| CN105143816B (en) | Three-dimensional shape measuring device, three-dimensional shape measuring method and three-dimensional shape measuring program | |
| CN113222965B (en) | Three-dimensional observation method for discharge channel | |
| TWI712310B (en) | Detection method and detection system for calibration quality of stereo camera | |
| WO2019087253A1 (en) | Stereo camera calibration method | |
| CN111292380B (en) | Image processing method and device | |
| CN109741384B (en) | Multi-distance detection device and method for depth camera | |
| Akasaka et al. | A sensor for simultaneously capturing texture and shape by projecting structured infrared light |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |