CN114943661B - Binocular camera-based target-free rock surface deformation field observation device and method - Google Patents

Binocular camera-based target-free rock surface deformation field observation device and method Download PDF

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CN114943661B
CN114943661B CN202210881083.4A CN202210881083A CN114943661B CN 114943661 B CN114943661 B CN 114943661B CN 202210881083 A CN202210881083 A CN 202210881083A CN 114943661 B CN114943661 B CN 114943661B
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rock
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CN114943661A (en
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王兆丰
潘鹏志
张文海
苗书婷
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Wuhan Institute of Rock and Soil Mechanics of CAS
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    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00—Image analysis
    • G06T7/30—Determination of transform parameters for the alignment of images, i.e. image registration
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    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00—Image analysis
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Abstract

The invention discloses a binocular camera-based target-free rock surface deformation field observation device and method, which can realize observation of a rock surface deformation field and an evolution process thereof without presetting a target, and improve the simplicity and accuracy of rock surface deformation field observation. The method for observing the rock surface deformation comprises the following steps: 1) Accurately observing the rock surface by using a binocular depth camera to obtain images of the rock surface at different moments; 2) Processing, analyzing and registering the left and right two-camera images at the same moment; 3) Obtaining elevation results of different positions on the surface of the rock at the same moment; 4) Generating natural rough fluctuating speckles; 5) And (4) calculating the rock surface deformation field according to correlation analysis, and performing alternate accumulation calculation at all times to obtain the evolution process of the rock surface deformation field. The device can provide guidance for roadway/tunnel surface deformation monitoring and disaster prevention and control.

Description

Binocular camera-based target-free rock surface deformation field observation device and method
Technical Field
The invention belongs to the field of rock mechanics and engineering, relates to a deformation field monitoring method, and more particularly relates to a binocular camera-based target-free rock surface deformation field observation device and method.
Background
The rock can generate a local deformation field under the influence of a plurality of external factors such as dynamic and static loads, the rock can be further developed into damage and destruction of the rock, the rock is subjected to disasters such as rock explosion, caving and the like in engineering construction such as mines, tunnels and the like, loss is caused to lives and properties of people, and the damage and destruction position and degree information of the rock can be judged by identifying the local deformation field through observation of the rock surface deformation field, so that the rock surface deformation field has a good early warning effect on the occurrence of disasters in the engineering. At present, the observation of the rock surface field needs to target the rock surface relevant position (for example, by spraying speckles and the like), so as to identify the rock surface target, obtain the change of the rock surface relevant position spatial position, and further calculate and obtain the rock surface deformation field. The method needs to target the rock surface in the observation process, has certain limitation on precision, and is difficult to be suitable for the tiny deformation of the rock surface. Therefore, there is a need to redesign a binocular camera-based target-free rock surface deformation field observation device and method.
Disclosure of Invention
The invention aims to provide a binocular camera-based target-free rock surface deformation field observation device and method aiming at the problems in the prior art, and the accuracy and simplicity of rock surface deformation field observation are improved.
The specific technical scheme is as follows:
target-free rock surface deformation field observation device based on binocular camera includes: the device comprises an observed rock, a left deep-eye camera and a right deep-eye camera;
the observed rock is the rock of the rock surface deformation field to be observed;
the left deep-eye camera and the right deep-eye camera are respectively positioned on the left and right sides of the surface of the rock to be observed of the observed rock;
the left eye camera and the right eye camera are respectively connected with the signal storage and processing module through signal cables.
The observation method of the binocular camera-based target-free rock surface deformation field observation device comprises the following specific steps:
firstly, acquiring rock surface image images at different moments through the device.
And step two, processing, analyzing and registering the left image and the right image of the rock surface at the same time obtained by the device.
And step three, obtaining elevation results of different positions on the surface of the rock at the same moment.
And step four, generating natural rough fluctuating speckles.
And fifthly, obtaining the rock surface deformation field and the evolution process thereof at any moment.
The method comprises the following specific steps:
firstly, acquiring rock surface image images at different moments through the device. And acquiring high-precision images, namely a left image and a right image, of the rock surface to be observed of the observed rock at different moments within observation time by using the left deep-eye camera and the right deep-eye camera.
And step two, processing, analyzing and registering the left image and the right image of the rock surface at the same time obtained by the device. Carrying out distortion processing on the left image and the right image, processing the images from a perspective scalene quadrangle into a rectangle, and ensuring that the left image and the right image are in the same proportion; filtering the left image and the right image to obtain filtered images; obtaining an RGB channel value and an RGB histogram of each pixel of the filtered left image and the filtered right image; overlapping the filtered left image and right image, fixing the left image and moving the right image, and setting the distance from the right camera image to the left camera asD(ii) a Calculating different distancesDSelecting the distance with the minimum average difference value according to the average difference of the RGB color histogramsDTo an optimum distanceD b And obtaining a registered image, wherein the intersection region of the left image and the right image after the processing is the key observation region.
And step three, obtaining elevation results of different positions of the rock surface at the same time. The focal lengths of the left eye camera and the right eye camera are bothf(ii) a The optical axis of the left eye camera is the left camera optical axis, and the mapping point of the left eye camera optical axis in the left image is the left camera reference point(ii) a The optical axis of the right eye depth camera is the optical axis of the right camera, and the mapping point of the right image is the reference point of the right camera; the distance between the optical axis of the left camera and the optical axis of the right camera isb(ii) a The mapping point of the left and right image registration points in the left image is a left mapping point, and the coordinates relative to the left camera reference point are
Figure 478207DEST_PATH_IMAGE001
(ii) a The registration point of the left and right images is the right mapping point in the right image, and the coordinates relative to the reference point of the right camera are
Figure 660926DEST_PATH_IMAGE002
(ii) a The spatial coordinates of the registration points of the left and right images are𝑋, Y,𝑍WhereinX,YThe different positions are indicated by means of a representation,Zindicating elevation.
Obtaining the elevations at different positions of the rock surface according to a triangulation positioning principle and an elevation calculation formula; the elevation calculation formula comprises:
Figure 345723DEST_PATH_IMAGE004
left mapped point, its coordinates
Figure 6512DEST_PATH_IMAGE005
Coordinates of the right mapping point
Figure 352043DEST_PATH_IMAGE002
Obtaining the mapping point coordinate according to a calculation formula; the mapping point coordinate calculation formula includes:
Figure 315451DEST_PATH_IMAGE007
wherein
Figure 848063DEST_PATH_IMAGE008
The number of pixels included in the left and right camera image units of millimeters,
Figure 578122DEST_PATH_IMAGE009
is the number of horizontal and vertical pixels of the left mapping point in the image of the left deep-field camera from the reference point of the left camera,
Figure 387946DEST_PATH_IMAGE010
is the number of longitudinal pixels of the right mapping point in the image of the right depth camera from the reference point of the right camera,
Figure 646889DEST_PATH_IMAGE011
the sign represents a plus or minus sign, and takes a value of minus one when located at the lower left of the reference point and takes a value of plus one when located at the upper right of the reference point;
and step four, generating natural rough fluctuating speckles. Dividing the rock surface elevation contour line image acquired by the device into a plurality of quadrilateral grid networks, wherein an undulation trend surface can be obtained in a single grid in the quadrilateral grid networks through fitting of an undulation trend calculation formula, and the undulation trend surface calculation formula comprises the following steps:
Figure 932377DEST_PATH_IMAGE012
whereinm，nAndlis the planar coefficient of the undulated trend surface.
Calculating the natural rough relief of the rock surface by adopting a natural rough relief calculation formula through the rock surface elevation contour line image acquired by the device and each grid relief trend surface in the quadrilateral grid network, wherein the natural rough relief calculation formula comprises:
Figure 810334DEST_PATH_IMAGE014
wherein
Figure 864878DEST_PATH_IMAGE015
The natural roughness of a certain pixel point on the surface of the rock.
And according to the natural rough undulation degree of the rock surface, selecting a reasonable undulation degree threshold value and carrying out binarization on the result of the natural rough undulation degree of the rock surface, wherein the value exceeding the undulation degree threshold value is set as black, and the value lower than the undulation degree threshold value is set as white, so that the natural rough undulation speckle obtained by the method is obtained.
The reasonable undulation threshold value can be obtained by equally dividing the rock surface natural rough undulation threshold value in the range of the lowest value and the highest value, calculating the speckle autocorrelation coefficient of each equally divided point, comparing the speckle autocorrelation coefficients of each equally divided point obtained by calculation and taking the undulation metric value corresponding to the maximum value.
And fifthly, obtaining the rock surface deformation field and the evolution process thereof at any moment. Selecting a reference sub-field of a certain pixel point in the image at the 0 th moment, searching each possible subset in the image at the 1 st moment, simultaneously calculating the correlation coefficient of the subset through a correlation coefficient calculation formula, and setting the maximum or minimum correlation coefficient as a deformed sub-field; calculating to obtain the deformation value of a certain pixel point at the 1 st moment by comparing the deformed subdomain and the reference subdomain with one-order shape characteristic transformation
Figure 560301DEST_PATH_IMAGE016
And calculating the deformation value of a certain pixel point on the rock surface corresponding to each moment and the previous moment according to the same method.
The image at the 0 th moment, the image at the 1 st moment and the like are the natural rough fluctuation speckle patterns of the rock surface on a tiny time interval determined according to the sampling frequency.
The correlation coefficient calculation formula includes:
Figure 441407DEST_PATH_IMAGE018
wherein
Figure 982110DEST_PATH_IMAGE019
In order to be a coefficient of correlation,
Figure 156739DEST_PATH_IMAGE020
is after deformationSub-field of
Figure 632851DEST_PATH_IMAGE021
The light intensity of the pixel points is measured,
Figure 892931DEST_PATH_IMAGE022
is a reference sub-field of
Figure 237325DEST_PATH_IMAGE021
The light intensity of the pixel points is measured,
Figure 876248DEST_PATH_IMAGE023
is the number of pixels of the sub-domain after deformation,
Figure 179053DEST_PATH_IMAGE024
is the average light intensity of all the pixel points of the subdomain after deformation,
Figure 395271DEST_PATH_IMAGE025
is the average light intensity of all the pixel points of the reference sub-field,
Figure 418722DEST_PATH_IMAGE026
is the standard deviation of the light intensity of all the pixel points of the subdomain after deformation,
Figure 302364DEST_PATH_IMAGE027
the standard deviation of the light intensity of all pixel points of the reference subdomain;
the rock surface deformation field at a certain moment can be obtained by calculating the deformation values of all pixel points on all rock surfaces
Figure DEST_PATH_IMAGE028
To obtain; for a certain time t, the rock surface deformation field at any time can be calculated according to a deformation field alternating accumulation formula, wherein the deformation field alternating accumulation formula comprises the following steps:
Figure DEST_PATH_IMAGE029
and the evolution process of the rock surface deformation field at any moment is the change of the rock surface deformation field before any moment.
Compared with the prior art, the invention has the following beneficial effects:
1. simplicity: the observation device and the observation method can save the steps of on-site target and the like, so that the installation of the device is simpler and more convenient;
2. the precision is high: the binocular depth camera has high precision which reaches a submillimeter level and can identify the tiny deformation of the rock surface;
3. intelligentization: the observation device can automatically identify the rock surface field after being installed, automatically observe the time-space change of the rock surface, and is particularly suitable for the construction of major projects;
drawings
FIG. 1 is a schematic view of the overall structure of the apparatus of the present invention;
FIG. 2 is a schematic view of the working flow of the observation method of the present invention;
FIG. 3 is a schematic diagram of the apparatus of the present invention for measuring elevation at different locations on a rock surface;
FIG. 4 is a schematic diagram of the device of the present invention for obtaining natural rough relief speckles;
FIG. 5 is a schematic diagram of the device of the present invention for obtaining rock surface deformation;
in the figure: the rock 1 under observation; a rock surface 2 to be observed; a left eye camera 3; a right eye camera 4; a signal cable 5; a signal storage and processing module 6; left and right image registration points 7; a left image 8; a right image 9; a left mapping point 10; a right mapping point 11; a left camera reference point 12; a right camera reference point 13; a left camera optical axis 14; a right camera optical axis 15; a rock surface elevation contour image 16 acquired by the apparatus; the natural rough relief speckles 17 obtained are processed by said method; a reference subfield 18; after deformation subdomain 19.
Detailed Description
To facilitate understanding and practice of the invention by those of ordinary skill in the art, the invention is described in further detail below with reference to the accompanying drawings, it being understood that the present examples are set forth merely to illustrate and explain the invention and are not intended to limit the invention.
The invention provides a binocular camera-based target-free rock surface deformation field observation device, which realizes observation of a target-free rock surface deformation field. The binocular camera-based target-free rock surface deformation field observation device is shown in figure 1; the method comprises the following steps:
the observed rock 1 is a rock of a rock surface deformation field to be observed;
the rock surface 2 to be observed is one surface of the rock 1 to be observed, which faces to the left deep-eye camera 3 and the right deep-eye camera 4;
the left deep-eye camera 3 is positioned in the left front of the observed rock 1, is opposite to the surface 2 of the rock to be observed, has an observation angle slightly inclined to the right, and is connected with the signal storage and processing module 6 through a signal cable 5;
the right deep-eye camera 4 is positioned at the right front of the observed rock 1, is opposite to the surface 2 of the rock to be observed, has an observation angle slightly inclined leftwards, and is connected with the signal storage and processing module 6 through a signal cable 5;
the signal cable 5 is connected with the left deep-eye camera 3, the right deep-eye camera 4 and the signal storage and processing module 6;
the signal storage and processing module 6 is connected with the left deep-vision camera 3 and the right deep-vision camera 4 through signal cables 5.
As shown in fig. 2, the binocular camera-based target-free rock surface deformation field observation device has the following working procedures:
1) Accurately observing the rock surface by using binocular depth cameras, namely a left deep-eye camera 3 and a right deep-eye camera 4, and obtaining images of the rock surface at different moments, namely a left image 8 and a right image 9;
2) After obtaining images at different moments, the binocular depth camera processes, analyzes and registers the left and right two-camera images at the same moment;
3) Obtaining elevation results at different positions on the surface of the rock at the same moment according to the matching results of the left binocular depth camera and the right binocular depth camera at the same moment;
4) Generating natural rough and fluctuant speckles according to elevation results of different positions of the surface of the rock at the same moment;
5) And according to the natural rough fluctuation speckle result of two adjacent moments with short time interval, taking the speckle pattern at the previous moment as a reference standard, analyzing and calculating the rock surface deformation field at the next moment according to the correlation, and alternately calculating all moments to obtain the evolution process of the rock surface deformation field.
The method for observing the surface deformation field of the target-free rock comprises the following specific steps:
firstly, acquiring rock surface image images at different moments through the device. High-precision images, namely a left image 8 and a right image 9, at different moments in observation time are obtained for the rock surface 2 to be observed of the observed rock 1 through the left deep-eye camera 3 and the right deep-eye camera 4.
And step two, processing, analyzing and registering the left image 8 and the right image 9 of the rock surface at the same time obtained by the device. As shown in fig. 2, the left image 8 and the right image 9 are distorted, the images are processed from a perspective scalene quadrangle into a rectangle, and the images are ensured to be in the same proportion; filtering the left image 8 and the right image 9 to obtain filtered images; obtaining an RGB channel value and an RGB histogram of each pixel of the filtered left image 8 and the filtered right image 9; overlapping the filtered left image 8 and right image 9, fixing the left image 8 and moving the right image 9, and setting the distance between the right camera image and the left camera asD(ii) a Calculating different distancesDAverage difference of RGB color histogram is selected, and the distance with minimum average difference value is selectedDTo an optimum distanceD b Thus, the registered image is obtained, and the intersection area of the left image 8 and the right image 9 after the processing is the key observation area.
And thirdly, obtaining elevation results of different positions of the rock surface at the same time by the method. As shown in fig. 2, the focal lengths of the left and right monocular cameras 3 and 4 are bothf(ii) a The optical axis of the left eye depth camera 3 is a left camera optical axis 14, and the mapping point of the left eye depth camera on the left image 8 is a left camera reference point 12; the optical axis of the right eye depth camera 4 is a right camera optical axis 15, and the mapping point of the right image 9 is a right camera reference point 13; the distance between the left camera optical axis 14 and the right camera optical axis 15 isb(ii) a The mapping point of the left and right image registration points 7 in the left image 8 is a left mapping point 10Coordinates relative to the left camera reference point 12 are
Figure 675271DEST_PATH_IMAGE001
(ii) a The left-right image registration point 7 is a right image 9 having a mapping point of a right mapping point 11 and coordinates with respect to a right camera reference point 13
Figure 378785DEST_PATH_IMAGE002
(ii) a The spatial coordinates of the registration points 7 of the left and right images are𝑋,Y,𝑍WhereinX,YWhich is indicative of a different position of the device,Zindicating elevation.
As shown in fig. 3, the elevations at different positions on the rock surface are obtained according to the triangulation principle and an elevation calculation formula; the elevation calculation formula comprises:
Figure DEST_PATH_IMAGE030
left mapping point 10, and coordinates of left mapping point 10
Figure 471506DEST_PATH_IMAGE005
And the coordinates of the right mapping point 11
Figure 350600DEST_PATH_IMAGE002
Obtaining the mapping point coordinate according to a calculation formula; the mapping point coordinate calculation formula comprises:
Figure DEST_PATH_IMAGE032
wherein
Figure 995208DEST_PATH_IMAGE008
The number of pixels included in the left and right camera image units of millimeters,
Figure DEST_PATH_IMAGE033
is the number of horizontal and vertical pixels of the left mapping point 10 from the left camera reference point 12 in the image of the left depth camera 3,
Figure 592543DEST_PATH_IMAGE010
is the number of vertical pixels of the right mapping point 11 in the image from the right camera reference point 13 in the right depth camera 4,
Figure 82430DEST_PATH_IMAGE011
representing a positive sign and a negative sign, and taking a value of negative one when the sign is positioned at the lower left of the datum point and taking a value of positive one when the sign is positioned at the upper right of the datum point;
and step four, generating natural rough fluctuating speckles. As shown in fig. 4, the rock surface elevation contour image 16 obtained by the device is divided into a plurality of quadrilateral grid networks, and a relief trend surface can be obtained in a single grid of the quadrilateral grid networks through fitting of a relief trend calculation formula, where the relief trend calculation formula includes:
Figure 48987DEST_PATH_IMAGE012
whereinm，nAndlthe plane coefficient of the fluctuation trend surface;
calculating the natural rough relief of the rock surface by adopting a natural rough relief calculation formula through the rock surface elevation contour image 16 acquired by the device and each grid relief trend surface in the quadrilateral grid network, wherein the natural rough relief calculation formula comprises:
Figure DEST_PATH_IMAGE034
wherein
Figure 864496DEST_PATH_IMAGE015
Is the natural roughness of the rock surface at a certain pixel point.
According to the natural rough undulation degree of the rock surface, a reasonable undulation degree threshold value is selected, and the result of the natural rough undulation degree of the rock surface is subjected to binarization, namely the value exceeding the undulation degree threshold value is set to be black, and the value lower than the undulation degree threshold value is set to be white, so that natural rough undulation speckles 17 obtained through the processing of the method are obtained, as shown in fig. 4.
The reasonable undulation threshold value can be obtained by equally dividing the rock surface natural rough undulation threshold value in the range of the lowest value and the highest value, calculating the speckle autocorrelation coefficient of each equally divided point, comparing the speckle autocorrelation coefficients of each equally divided point obtained by calculation and taking the undulation metric value corresponding to the maximum value.
And fifthly, obtaining the rock surface deformation field and the evolution process thereof at any moment. As shown in fig. 5, a reference sub-field 18 of a certain pixel point is selected in the image at the 0 th moment, at the same time, every possible subset is searched in the image at the 1 st moment, the correlation coefficient is calculated through a correlation coefficient calculation formula, and the maximum or minimum correlation coefficient is set as a deformed sub-field 19; calculating the deformation value of a certain pixel point at the 1 st moment by comparing the deformed first-order shape characteristic transformation of the subdomain 19 and the reference subdomain 18
Figure 542602DEST_PATH_IMAGE016
(ii) a According to the same method, the deformation value of a certain pixel point on the rock surface corresponding to each moment and the previous moment can be calculated.
The image at the 0 th moment, the image at the 1 st moment and the like are rock surface natural rough and fluctuant speckle patterns on a tiny time interval determined according to sampling frequency.
The correlation coefficient calculation formula includes:
Figure DEST_PATH_IMAGE035
wherein
Figure 242705DEST_PATH_IMAGE019
In order to be a coefficient of correlation,
Figure 830812DEST_PATH_IMAGE020
is the sub-region 19 th after deformation
Figure 286064DEST_PATH_IMAGE021
The light intensity of the pixel points is measured,
Figure 451466DEST_PATH_IMAGE022
is the reference subfield 18 th
Figure 424101DEST_PATH_IMAGE021
The light intensity of the pixel points is measured,
Figure 991349DEST_PATH_IMAGE023
the number of pixels of the sub-domain after deformation,
Figure 617502DEST_PATH_IMAGE024
is the average light intensity of all the pixels of subfield 19 after deformation,
Figure 270201DEST_PATH_IMAGE025
is the average light intensity of all the pixels in the reference subfield 18,
Figure 545062DEST_PATH_IMAGE026
is the standard deviation of the light intensities of all the pixels of the subdomain 19 after deformation,
Figure 701237DEST_PATH_IMAGE027
is the standard deviation of the light intensities of all the pixel points of the reference subfield 18;
the rock surface deformation field at a certain moment can be obtained by calculating the deformation values of all pixel points on all rock surfaces
Figure 763871DEST_PATH_IMAGE028
To obtain the final product. As shown in fig. 5, for a certain time t, the rock surface deformation field at any time can be calculated according to a deformation field alternating and accumulating formula, wherein the deformation field alternating and accumulating formula comprises:
Figure 779231DEST_PATH_IMAGE029
and the evolution process of the rock surface deformation field at any moment is the change of the rock surface deformation field before any moment.

Claims (2)

1. The observation method of the binocular camera-based target-free rock surface deformation field observation device comprises the following steps: the rock observation system comprises an observed rock (1), a left deep-eye camera (3) and a right deep-eye camera (4);
the observed rock (1) is a rock of a rock surface deformation field to be observed;
the left deep-vision camera (3) and the right deep-vision camera (4) are respectively positioned on the left and right sides of the rock surface (2) to be observed of the observed rock (1);
the left deep-vision camera (3) and the right deep-vision camera (4) are respectively connected with the signal storage and processing module (6) through signal cables (5);
the method is characterized by comprising the following specific steps:
firstly, acquiring rock surface image images at different moments through the device;
the method comprises the following specific steps:
rock surface image images at different moments are obtained through the device; high-precision images, namely a left image (8) and a right image (9), at different moments in observation time are acquired for the rock surface (2) to be observed of the observed rock (1) through a left deep-eye camera (3) and a right deep-eye camera (4);
step two, processing, analyzing and registering a left image (8) and a right image (9) of the rock surface at the same time obtained by the device;
step two, the concrete steps are as follows:
processing, analyzing and registering a left image (8) and a right image (9) of the rock surface at the same time obtained by the device; carrying out distortion processing on the left image (8) and the right image (9), processing the images from a perspective scalene quadrangle into a rectangle, and ensuring that the images are in the same proportion; filtering the left image (8) and the right image (9) to obtain filtered images; obtaining an RGB channel value and an RGB histogram of each pixel of the filtered left image (8) and the filtered right image (9);overlapping the filtered left image (8) and right image (9) and fixing the left image (8) and moving the right image (9) at the same time, and setting the distance from the right camera image to the left camera asD(ii) a Calculating different distancesDAverage difference of RGB color histogram is selected, and the distance with minimum average difference value is selectedDTo an optimum distanceD b Obtaining a registered image, wherein the intersection area of the left image (8) and the right image (9) after processing is a key observation area;
thirdly, obtaining elevation results of different positions of the rock surface at the same time;
step three, the concrete steps are as follows:
obtaining elevation results of different positions on the surface of the rock at the same moment; the focal lengths of the left deep-vision camera (3) and the right deep-vision camera (4) are bothf(ii) a The optical axis of the left eye depth camera (3) is a left camera optical axis (14), and the mapping point of the left eye depth camera on the left image (8) is a left camera reference point (12); the optical axis of the right eye depth camera (4) is a right camera optical axis (15), and the mapping point of the right image (9) is a right camera reference point (13); the distance between the left camera optical axis (14) and the right camera optical axis (15) isb(ii) a The mapping point of the left and right image registration points (7) in the left image (8) is a left mapping point (10), and the coordinates of the left and right image registration points relative to the left camera reference point (12) are
Figure DEST_PATH_IMAGE001
(ii) a The left and right image registration points (7) are right image registration points (11) in a right image (9), and the coordinates thereof with respect to a right camera reference point (13) are
Figure 596446DEST_PATH_IMAGE002
(ii) a The space coordinates of the registration points (7) of the left and right images are𝑋,Y,𝑍WhereinX,YWhich is indicative of a different position of the device,Zrepresenting elevation;
obtaining the elevations at different positions of the rock surface according to a triangulation positioning principle and an elevation calculation formula; the elevation calculation formula comprises:
Figure 872707DEST_PATH_IMAGE004
a left mapping point (10), and the coordinates of the left mapping point (10)
Figure DEST_PATH_IMAGE005
Coordinates of the right mapping point (11)
Figure 11302DEST_PATH_IMAGE002
Obtaining the mapping point coordinate according to a calculation formula; the mapping point coordinate calculation formula includes:
Figure DEST_PATH_IMAGE007
wherein
Figure 904171DEST_PATH_IMAGE008
The number of pixels included in the left and right camera image units of millimeters,
Figure DEST_PATH_IMAGE009
is the number of horizontal and vertical pixels of a left mapping point (10) in an image of a left eye depth camera (3) from a left camera reference point (12),
Figure 287879DEST_PATH_IMAGE010
is the number of longitudinal pixels of a right mapping point (11) in an image of a right depth camera (4) from a right camera reference point (13),
Figure DEST_PATH_IMAGE011
the sign represents a plus or minus sign, and takes a value of minus one when located at the lower left of the reference point and takes a value of plus one when located at the upper right of the reference point;
generating natural rough and fluctuant speckles;
step four, the concrete steps are as follows:
generating natural rough fluctuating speckles; dividing a rock surface elevation contour image (16) acquired by the device into a plurality of quadrilateral grid networks, wherein a fluctuation trend surface can be obtained in a single grid of the quadrilateral grid networks through fitting of a fluctuation trend calculation formula, and the fluctuation trend calculation formula comprises:
Figure 559592DEST_PATH_IMAGE012
whereinm，nAndlthe plane coefficient of the undulation trend surface;
the natural rough relief of the rock surface is calculated by adopting a natural rough relief calculation formula through a rock surface elevation contour line image (16) obtained by the device and each grid relief trend surface in the quadrilateral grid network, wherein the natural rough relief calculation formula comprises the following steps:
Figure 229607DEST_PATH_IMAGE014
wherein
Figure DEST_PATH_IMAGE015
The natural roughness of a certain pixel point on the surface of the rock;
according to the natural rough and undulation degree of the rock surface, selecting a reasonable undulation degree threshold value and carrying out binarization on the result of the natural rough and undulation degree of the rock surface, wherein the value exceeding the undulation degree threshold value is set as black, and the value lower than the undulation degree threshold value is set as white, so that natural rough and undulation speckles (17) obtained by the method processing are obtained;
the reasonable undulation threshold value can be obtained by equally dividing the rock surface natural rough undulation threshold value in the range of the lowest value and the highest value, calculating the speckle autocorrelation coefficient of each equally divided point, comparing the speckle autocorrelation coefficients of each equally divided point obtained by calculation and taking the undulation metric value corresponding to the maximum value;
and fifthly, obtaining the rock surface deformation field and the evolution process thereof at any moment.
2. The observation method of the binocular camera-based target-free rock surface deformation field observation device according to claim 1, wherein the step five specifically comprises the following steps:
obtaining a rock surface deformation field and an evolution process thereof at any moment; selecting a reference sub-field (18) of a certain pixel point in the image at the 0 th moment, searching each possible subset in the image at the 1 st moment, simultaneously calculating the correlation coefficient of the subset through a correlation coefficient calculation formula, and setting the maximum or minimum correlation coefficient as a deformed sub-field (19); the deformation value of a certain pixel point at the 1 st moment is calculated by comparing the first-order shape characteristic transformation of the deformed subdomain (19) and the reference subdomain (18)
Figure 485139DEST_PATH_IMAGE016
(ii) a Calculating the deformation value of a certain pixel point on the rock surface corresponding to each moment and the previous moment according to the same method;
the image at the 0 th moment, the image at the 1 st moment and the like are natural rough and fluctuant speckle patterns of the rock surface on a tiny time interval determined according to the sampling frequency;
the correlation coefficient calculation formula includes:
Figure DEST_PATH_IMAGE017
wherein
Figure 266014DEST_PATH_IMAGE018
In order to be the correlation coefficient,
Figure DEST_PATH_IMAGE019
is that the sub-region (19) after deformation is first
Figure 421926DEST_PATH_IMAGE020
The light intensity of the pixel points is measured,
Figure DEST_PATH_IMAGE021
is in reference to the sub-field (18) of the first
Figure 403789DEST_PATH_IMAGE020
The light intensity of the pixel points is measured,
Figure 740092DEST_PATH_IMAGE022
the number of pixels of the sub-domain after deformation,
Figure DEST_PATH_IMAGE023
is the average light intensity of all pixel points of the subdomain (19) after deformation,
Figure 465603DEST_PATH_IMAGE024
is the average light intensity of all pixel points of the reference sub-field (18),
Figure DEST_PATH_IMAGE025
is the standard deviation of the light intensity of all the pixel points of the subdomain (19) after deformation,
Figure 836541DEST_PATH_IMAGE026
is the standard deviation of the light intensity of all pixel points of the reference sub-field (18);
the rock surface deformation field at a certain moment can be obtained by calculating the deformation values of all pixel points on all rock surfaces
Figure DEST_PATH_IMAGE027
To obtain; for a certain time t, the rock surface deformation field at any time can be calculated according to a deformation field alternating accumulation formula, wherein the deformation field alternating accumulation formula comprises the following steps:
Figure 989305DEST_PATH_IMAGE028
and the evolution process of the rock surface deformation field at any moment is the change of the rock surface deformation field before any moment.
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