CN115585740A - Detection device and measurement method for spatial coordinates of explosion points - Google Patents

Detection device and measurement method for spatial coordinates of explosion points Download PDF

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CN115585740A
CN115585740A CN202211316441.3A CN202211316441A CN115585740A CN 115585740 A CN115585740 A CN 115585740A CN 202211316441 A CN202211316441 A CN 202211316441A CN 115585740 A CN115585740 A CN 115585740A
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explosion
point
image
cannonball
target
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王泽民
刘敏
王守民
雷志勇
李静
史志军
闫克丁
雷秉山
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Xian Technological University
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    • GPHYSICS
    • G01MEASURING; TESTING
    • G01BMEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00Measuring arrangements characterised by the use of optical techniques
    • G01B11/002Measuring arrangements characterised by the use of optical techniques for measuring two or more coordinates
    • G01B11/005Measuring arrangements characterised by the use of optical techniques for measuring two or more coordinates coordinate measuring machines

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Abstract

The invention discloses a detection device and a measurement method for a spatial coordinate of a frying point, comprising an image processing system; arranging an infrared detection device in a terminal ballistic trajectory safety region, uniformly arranging at least one high-speed camera on two sides of a ballistic trajectory, enabling the pre-explosion range of the cannonball to be in the intersection detection visual field region, placing a test marker post at a theoretical explosion point, and measuring the coordinate of the test marker post; arranging a canopy target triggering device in a safety area below a front-end pre-trajectory at a distance of 300-500 meters from the centers of the high-speed cameras on two sides of the trajectory, and arranging an explosion point image processing system and a Beidou time management device in a safety area outside an explosion point; the high-speed camera is respectively connected with the sky screen target triggering device, the explosion point image processing system and the Beidou time system device, and the infrared detection device and the Beidou time system device are connected with the explosion point image processing system. The method solves the problems that the time consumption and inaccuracy are caused by the fact that the frame frequency of a high-speed camera is limited and the image storage capacity is large in the measurement of the spatial coordinates of the explosion points, and improves the precision of the measurement of the spatial coordinates of the explosion points.

Description

Detection device and measurement method for spatial coordinates of explosion points
Technical Field
The invention relates to the field of image processing technology and target detection, in particular to a detection device and a measurement method for a spatial coordinate of a frying point.
Background
In a firing range test, measurement of space coordinates of explosion points is one of the most important test items of a conventional firing range, and the method has important significance for damage performance evaluation of a weapon system. The common methods for measuring the spatial coordinates of the explosion points mainly comprise 3 methods: photoelectric measurement, acoustic sensor measurement, and image measurement. The photoelectric measurement mainly adopts the photoelectric theodolite to measure the coordinates of the explosion points, the starting is early, the application is wide, the automation degree is higher, and the current explosion point theodolite is the main near-ground explosion point measuring equipment of a target range. However, in practical application, the focal length is fixed mostly, the lens and the camera are packaged integrally and cannot be replaced, the application range is limited aiming at different test requirements, and the traditional explosive point theodolite catches a first frame of explosive image due to low frame frequency, so that the light is large, and the extraction precision of pixel coordinates of the explosive point is influenced. The acoustic sensor measures the flying direction of the cannonball and the three-dimensional coordinates of the explosion point by acquiring the explosion shock wave information radiated to the periphery during explosion, combining a sky screen target and a flame detector of the explosion point and utilizing a multi-sensor information fusion theory. The array is flexible in arrangement, wide in detection range and far in distance, is not influenced by visibility and observation visual field shielding, and can be used all the day long. However, the explosion sound waves are greatly influenced by the landform and the environment of the falling area of the cannonball, sound wave signals are easy to adhere and mix up, and the positioning error is large. The image measuring method utilizes a high-speed camera to track and shoot a measuring target, has the advantages of convenience in station arrangement and flexible replacement of multiple lenses, and is more applied to a target range test in recent years. Because the explosion fire light of the cannonball expands rapidly at the moment of explosion and generates smoke, the fire light of the cannonball is maintained for only a few milliseconds, so that the cannonball has high speed and instantaneity, and the image information of the fire light at the first moment of the explosion moment cannot be captured frequently due to the limit of the frame frequency of a high-speed camera.
Disclosure of Invention
The invention provides a device and a method for detecting three-dimensional coordinates of an air explosion point, solves the problems that time consumption and inaccuracy are caused when images of the explosion point are searched due to limited frame frequency and large image storage capacity of a high-speed camera in the measurement of the space coordinates of the explosion point, and improves the precision of the measurement of the coordinates of the explosion point.
The invention is realized by the following technical scheme:
a detection device for a spatial coordinate of a explosion point comprises an infrared detection device, a dome target triggering device, a test marker post, an explosion point image processing system, a Beidou time system device and at least two high-speed cameras; respectively erecting at least one high-speed camera on two sides of a trajectory at a station distribution position of a safe region of an end point trajectory by using a tripod, performing rock mass protection, enabling a pre-explosion range of a shell to be positioned in an intersection detection view field region of the high-speed cameras on two sides of the end point trajectory, distributing an infrared detection device in the safe region of a theoretical explosion point of the end point trajectory by using the tripod, performing rock mass protection, enabling the pre-explosion point of the shell to be positioned in the detection view field region of the infrared detection device, distributing a sky screen target trigger device in the safe region below the pre-explosion point which is 300-500 meters away from the front end of the central position of the high-speed cameras on two sides of the end point trajectory, placing a test marker rod at the theoretical explosion point, measuring the coordinates of the test marker rod, distributing an explosion point image processing system and a Beidou satellite system outside the explosion point, and setting a safe region, and setting a rock mass protection trajectory; the high-speed camera is respectively connected with the sky screen target triggering device, the explosion point image processing system and the Beidou time system device, and the infrared detection device and the Beidou time system device are connected with the explosion point image processing system.
The test benchmarks are at least two groups of test benchmarks.
The high-speed camera is used for synchronously shooting sequence image information of a target cannonball in an end point trajectory from a plurality of angles and in a close range; the sky-screen target triggering device is used for providing uniform triggering signals for the high-speed cameras on two sides of the trajectory so as to ensure that the high-speed cameras are provided with accurate synchronous starting shooting signals when the cannonball flies over the sky-screen target triggering device, so that the high-speed cameras can accurately shoot image information of the cannonball before and after explosion, and the storage capacity of the image information of the high-speed cameras is reduced; the device comprises an infrared detection device, a test marker post and a high-speed camera, wherein the infrared detection device is used for capturing an infrared signal of a shell explosion point and transmitting the infrared signal to a explosion point image processing system to determine the explosion time information of the shell so as to quickly extract an accurate and reliable shell explosion point image; the bomb spot image processing system is used for acquiring bomb image information by adopting image framing according to the bomb explosion time information provided by the infrared detection device for the target bomb sequence image information captured by the high-speed camera and judging the bomb image information; if the camera shoots the image of the explosion time point at the time point of the explosion of the cannonball, calculating the space coordinate of the explosion point by adopting the frame of image; if the camera does not shoot the image of the explosion time point at the time point of the explosion of the cannonball, extracting cannonball image information when a frame is not detonated before explosion and cannonball flare image information when a first frame appears flare after the cannonball explodes, acquiring explosion point image information of the first moment when the cannonball detonates by adopting an image frame interpolation algorithm and combining a cannonball explosion flare model and the cannonball explosion moment, and calculating the explosion point space three-dimensional coordinate and the explosion moment information of the first moment when the cannonball explodes by utilizing the explosion point image information.
A method for measuring a spatial coordinate of a frying point by using a spatial coordinate detecting device of the frying point comprises the following steps:
step 1): the bomb explosion point image processing system receives target bomb sequence image information sent by the high-speed camera and bomb explosion time information sent by the infrared detection device in real time, rapidly extracts bomb image information of a bomb explosion point area by adopting a video framing method according to the bomb explosion time information provided by the infrared detection device, judges whether the high-speed camera shoots an image of an explosion time point or not, and executes the following two operation modes;
the first method is as follows: if the time point of the explosion of the cannonball in the cannonball image information is judged, the high-speed camera shoots the explosion time pointThe image of the explosion time point is an image Gd 'of the explosion point when the shell explodes' 0 (u e ,v e ,t 0 ) Then, a background subtraction and morphological filtering method is adopted to detect and identify the explosion point image information of the explosion moment of the cannonball and the corresponding moment T n0
The second method comprises the following steps: if the fact that the camera does not shoot the image of the explosion time point at the time point of the explosion of the shell in the shell image information is judged, the shell explosion time information point obtained by an infrared detection device is utilized, and background subtraction and morphological filtering methods are adopted to quickly extract the shell image information before explosion when the explosion frame is not detonated, shell flare image information after the explosion of the shell and the first frame of flare after the explosion of the shell and corresponding time T of each frame n-1 、T n1
Then, calculating each pixel point of the interpolated frame image by adopting a frame mixing frame interpolation algorithm in the image frame interpolation algorithm and combining a shell explosion fireball expansion model to generate an intermediate frame image Gd 0 (u e ,v e ,t 0 ) Namely, the image information of the explosion point at the explosion moment of the cannonball;
the generated intermediate frame image is analyzed, and two situations exist: 1) After the image frames of the explosion point when the shell and the shell are detonated are mixed, no superposition or partial superposition exists, and the explosion point coordinate of the intermediate frame image is the intermediate point of the shell coordinate and the central coordinate of the explosion point image when the shell is detonated; 2) After the image frames of the explosion points when the shell and the shell are detonated are mixed, the shell target is completely superposed with the flare image, and the explosion point coordinate of the intermediate frame image is the center coordinate of the explosion point image when the shell is detonated;
step 2): detonation Point image Gd 'of detonation of the Shell obtained in mode one' 0 (u e ,v e ,t 0 ) Or intermediate frame image Gd obtained by the second mode 0 (u e ,v e ,t 0 ) Computing a shot point coordinate (u) using a moment-based barycentric coordinate extraction algorithm p0 ,v p0 );
Step 3): resolving the internal and external calibration parameters of the camera according to the test benchmarking image to obtain system calibration data; by establishing an image pixel coordinate system, an image coordinate system, a phaseCombining the machine coordinate system and the world coordinate system, solving a space explosion point coordinate model by combining the conversion relation among the coordinate systems, and obtaining an explosion point coordinate (u) p0 ,v p0 ) And substituting the space explosion point coordinate model with the space explosion point coordinate model to solve the space coordinate and the explosion time of the explosion point.
The method also comprises the following steps before the step 1):
step 4): arranging an infrared detection device, a backdrop target triggering device, a blast point image processing system, a Beidou time system device, two groups of test benchmarks and at least two high-speed cameras arranged at two sides of a terminal trajectory in a safe area of the terminal trajectory; mounting each device to form a detection device of the spatial coordinates of the explosion points;
step 5): when a target cannonball passes through a detection area of a dome target trigger device, the dome target trigger device outputs a trigger signal, high-speed cameras on two sides of a trajectory are started to acquire real-time continuous high-frame-frequency video images of the target cannonball, the acquired images are cached to obtain sequence image information of the target cannonball, and the obtained sequence image information of the target cannonball is sent to a blast point image processing system; and the sky screen target triggering device also starts the infrared detection device at the same time, and the infrared detection device starts to collect the shell explosion time information in real time and sends the collected shell explosion time information to the explosion point image processing system.
The step 4) is specifically as follows:
respectively erecting at least one high-speed camera on two sides of a trajectory by using a tripod at the station distribution position of a safe region of an end point trajectory, performing rock mass protection, enabling a pre-explosion range of a shell to be positioned in an intersection detection view field region of the high-speed cameras on the two sides of the end point trajectory, distributing an infrared detection device in the safe region of a theoretical explosion point of the end point trajectory, performing rock mass protection, enabling the pre-explosion point of the shell to be positioned in the detection view field region of the infrared detection device, distributing a dome target trigger device in the safe region below the pre-explosion point at a distance of 300-500 meters away from the centers of the high-speed cameras on the two sides of the trajectory, placing at least two groups of test rods at the theoretical explosion point, measuring the coordinates of the test rods, distributing an explosion point image processing system and a Beidou time system outside the explosion point, and setting rock mass protection; the high-speed camera is respectively connected with the sky screen target triggering device, the explosion point image processing system and the Beidou time system device, and the infrared detection device and the Beidou time system device are connected with the explosion point image processing system;
the step 5) is specifically as follows: when a target cannonball passes through a light curtain formed by a canopy target optical lens in a detection area of a canopy target trigger device, as the target cannonball shields a part of light, the luminous flux reaching the photosensitive surface of a photoelectric sensor on the canopy target optical lens is changed, the changed luminous flux is subjected to the processing of extraction, amplification, noise filtering and level conversion circuits through an analog circuit, and finally a TTL level signal with fixed pulse width is output to high-speed cameras on two sides of a trajectory, the high-speed cameras on the two sides of the trajectory are started to carry out real-time continuous high-frame-frequency video image acquisition on the target cannonball, the acquired images are cached to obtain target cannonball sequence image information, and the obtained target cannonball sequence image information is sent to a shot point image processing system; and the sky screen target triggering device also starts the infrared detection device at the same time, and the infrared detection device starts to collect the shell explosion time information in real time and sends the collected shell explosion time information to the explosion point image processing system.
The step 1) is specifically as follows:
step 1): the explosion point image processing system receives target cannonball sequence image information sent by a high-speed camera and cannonball explosion time information sent by an infrared detection device in real time, quickly extracts the start and stop time of target cannonball video information before and after the detonation of a cannonball in the target cannonball sequence image information according to the cannonball explosion time information provided by the infrared detection device, and derives each frame JPEG image I (u) with time marks by adopting a video framing method e ,v e T), then quickly extracting cannonball image information of an explosion point area, judging the cannonball image information, judging whether an image of an explosion time point is shot by a high-speed camera or not, and executing the following two operation modes;
the method I comprises the following steps: if the camera judges that the image of the explosion time point is shot by the shell image information at the explosion time point of the shell, the image of the explosion time point is obtainedThe image is a firing point image Gd 'during shell detonation' 0 (u e ,v e ,t 0 ) Acquiring a frame of image before the cannonball enters a visual field as a background image M bg (u e ,v e ,t 0 ) (ii) a Explosive point image Gd 'upon detonation of cannonball with time marks' 0 (u e ,v e ,t 0 ) Background subtraction is carried out by adopting a background difference algorithm, and then the background subtracted multi-gray-level shell is detonated with a explosive point image Gd' 0 (u e ,v e ,t 0 ) Performing binarization processing, determining a threshold value by adopting a maximum inter-class variance method, setting the pixel value greater than or equal to the threshold value as 1, and setting the pixel value less than the threshold value as 0; then, a morphological filtering method is adopted to carry out detonation point image Gd 'on the shells after binarization processing' 0 (u e ,v e ,t 0 ) Performing opening operation filtering treatment of corrosion and expansion, removing small particle noise, smoothing target boundary, and accurately extracting explosive point target or cannonball target and flare target without changing shape and area thereof to obtain explosive point image information Gd at the cannonball explosion time n0 (u e ,v e ,t n0 ) And corresponding time T n0
The second method comprises the following steps: if the fact that the camera does not shoot the image of the explosion time point at the time point of the explosion of the cannonball in the cannonball image information is judged, the cannonball explosion time information point obtained by the infrared detection device is utilized, target cannonball sequence image information is rapidly extracted from the cannonball image information, and the previous frame image of the cannonball entering the visual field is obtained and used as a background image M bg (u e ,v e ,t 0 ) (ii) a Background subtraction is carried out on the image information of the target cannonball sequence with the time marks by adopting a background difference algorithm, binarization processing is carried out on the image information of the target cannonball sequence with multiple gray levels after the background subtraction processing, a threshold value is determined by adopting a maximum inter-class variance method, the pixel value which is greater than or equal to the threshold value is set as 1, and the pixel value which is less than the threshold value is set as 0; then, performing open operation filtering processing of firstly corroding and then expanding on the binaryzation processed target cannonball sequence image information by adopting a morphological filtering method, removing small-particle noise, and smoothingAccurately extracting a explosive point target or a cannonball target and a flare target without changing the shape and the area of the target boundary to obtain cannonball image information Gd when the cannonball is not detonated in the frame before explosion n-1 (u e ,v e ,t n-1 ) And the shell flare image information Gd when the flare appears in the first frame after the explosion of the shell n1 (u e ,v e ,t n1 ) And each frame corresponds to a time T n-1 、T n1
Then, the shell image Gd of the non-detonation previous frame after the morphological filtering processing n-1 (u e ,v e ,t n-1 ) And a cannonball flare image Gd when flare appears in the first frame after the cannonball explosion n1 (u e ,v e ,t n1 ) Substituting into an interpolation frame algorithm, combining with a shell explosion fireball expansion model, assuming that the weight of a frame before detonation is L-alpha/L, the weight of a first frame of image after detonation is alpha/L, multiplying two reference frames by respective weights, and adding to obtain an intermediate frame image Gd 0 (u e ,v e ,t 0 ) (ii) a The algorithm is as follows:
Figure BDA0003908900330000071
wherein, L is the distance between two frames of the original frame, and alpha is the relative distance between the frame before detonation and the inserted frame;
the frame insertion time is:
T n0 =T n-1
in the second method, the generated inter-frame image is analyzed, and there are two cases:
(1) If the cannonball and the flare image are overlapped or partially overlapped, the coordinates of the explosion point of the intermediate frame image are intermediate points of the cannonball coordinates and the central pixel coordinates of the flare image; (2) If the cannonball target is completely overlapped with the flare image, the coordinates of the explosion point of the intermediate frame image are the coordinates of the central pixel of the flare image;
the step 2) is specifically as follows:
firing Point image Gd 'upon detonation of the projectile obtained in the first embodiment' 0 (u e ,v e ,t 0 ) Or intermediate frame image Gd obtained by the second mode 0 (u e ,v e ,t 0 ) Computing a shot point coordinate (u) using a moment-based barycentric coordinate extraction algorithm p0 ,v p0 ) (ii) a Let the quality of each pixel in the region of the explosion point in the image be 1, i.e. the quality of each pixel is equal to its pixel value, (u) e ,v e ) For the coordinates of the image pixel, S is the area of the pixel region, the p + q order moment of the target can be expressed as:
Figure BDA0003908900330000072
where M is the moment of the image at different values of p, q, f (u) e ,v e ) Is the quality of one pixel; respectively calculating the zero order moment and the first order moment thereof, wherein the three conditions are as follows:
when p =0, q =0, the obtainable zero order moment M (0,0) is:
Figure BDA0003908900330000073
when p =1,q =0, the first moment M (0,1) is:
Figure BDA0003908900330000081
when p =0,q =1, the first moment M (1,0) has the value:
Figure BDA0003908900330000082
the barycenter of the target image can be calculated by using the zeroth order moment and the first order moment, and is used as (u) p0 ,v p0 ) And representing the coordinates of the frying point, wherein the solving algorithm of the coordinates of the frying point is as follows:
Figure BDA0003908900330000083
wherein M (1,0) represents the sum of the abscissa of all pixels of the bullet hole, M (0,1) represents the sum of the column coordinates of all pixels of the bullet hole, and M (0,0) represents the number of pixels contained in the bullet hole;
the step 3) is specifically as follows: solving a space explosion point coordinate model and bringing explosion point coordinates into the space explosion point coordinate model to solve explosion point space three-dimensional coordinates:
the three-dimensional coordinate of the space explosion point P in the world coordinate system is assumed to be (X) P ,Y P ,Z P ) The imaged image coordinate is (u) P ,v P ) (ii) a The high speed camera linear model can be expressed as:
Figure BDA0003908900330000084
the camera distortion model is as follows:
Figure BDA0003908900330000085
Figure BDA0003908900330000086
wherein,
Figure BDA0003908900330000087
considering the second-order radial distortion, the distortion coefficient is a 1 、a 2 (ii) a λ is a scale factor, (u) w ,v w ) For undistorted image coordinates, (R, T) are extrinsic parameters of the camera, R and T are the rotation matrix and translation vector from the world coordinate system to the camera coordinate system, respectively, a is the camera intrinsic parameter matrix, which can be expressed as:
Figure BDA0003908900330000088
in the formula (u) 0 ,v 0 ) As principal point coordinates of an image coordinate system, f x 、f y Are respectively u-axisAnd a scale factor for the v-axis, α being a non-perpendicular factor for the u-axis and the v-axis; high-speed camera calibration of 5 parameters f of internal parameter matrix of camera to be referenced x 、f y 、α、u 0 And v 0 And a distortion coefficient a 1 、a 2
Before testing, two standard test benchmarks rotate in multiple directions within the range of the pre-explosion point of the cannonball, and a high-speed binocular camera is adopted to shoot moving images of the multiple standard test benchmarks at the pre-explosion point of the cannonball in different directions; resolving 5 parameters and a camera distortion coefficient calibrated by a camera according to an imaging relation of characteristic points on a standard test target on a binocular camera consisting of high-speed cameras on two sides;
the transformation relation from the pixel coordinate system to the world coordinate system is obtained by establishing an image pixel coordinate system, an image coordinate system, a camera coordinate system and the world coordinate system and combining the transformation relation among the coordinate systems as follows:
Figure BDA0003908900330000091
wherein Z is c Is 1,s as the coordinate axis tilt parameter, in the ideal case 0,A is the camera intrinsic parameter matrix, the orthogonal rotation matrix R is the cosine combination of the camera coordinate system with respect to the direction of the coordinate axis of the world coordinate system, and the translation matrix T = [ T ] 1 t 2 t 3 ] T Is the coordinate of the origin of the camera coordinate system under the world coordinate system; by further solving the above equation, the conversion relationship between the system pixel coordinate and the world coordinate system can be obtained as follows:
Figure BDA0003908900330000092
order to
Figure BDA0003908900330000093
The above formula can be simplified to the following space fryer point coordinate model:
[X Y Z 1] T =C -1 [u v 1] T
in the formula, (X, Y, Z) is the solved coordinates of the space explosion point, and the unit is meter; (u, v) are pixel coordinates in pixels;
wherein, the coordinates (u) of the frying point obtained in the step 2) are used p0 ,v p0 ) And substituting the three-dimensional space coordinates into the upper formula space explosion point coordinate model to obtain explosion time explosion point space three-dimensional coordinates (X, Y and Z).
Compared with the prior art, the invention has the following beneficial technical effects:
the invention provides a detection device and a measurement method for explosion point space coordinates, which can rapidly extract the cannonball image information of an explosion point area from the cannonball sequence image information shot by a high-speed camera by adopting a video framing method based on the cannonball explosion time information provided by an infrared detection device, can directly obtain the explosion point image information by judging, and then can calculate the space three-dimensional coordinates of the explosion point in the air, thereby improving the working efficiency and reducing the labor intensity, or can rapidly extract the cannonball image information when the former frame before explosion is not detonated and the cannonball flare image information when the first frame appears flare after the cannonball explodes from the cannonball image information, thereby rapidly finding the explosion point coordinates, improving the working efficiency and reducing the labor intensity, simultaneously, fully utilizing the relation between the camera shooting sequence images in the explosion point forming process by utilizing a binocular high-speed camera detection mechanism, generating a more accurate first frame flare light image at the explosion point explosion time by adopting an image frame interpolation method, forming continuous frame images, combining binocular vision to detect and calculate the space three-dimensional coordinates of the explosion point, solving the problem that the explosion point information cannot be captured by the explosion initial time frame frequency limitation of the cannonball, thereby improving the calculation precision.
The device and the method for detecting the explosion point space coordinate solve the technical problem that in the prior art, the explosion light diffusion speed is high, the image information of the explosion fireball at the initial moment of explosion cannot be captured due to the limitation of the frame frequency of a high-speed camera, the image of the explosion fireball in the first frame after explosion is very large and even changed into irregular fireball, and the like, so that the calculation of the instantaneous coordinate of the detonation of the fireball has large deviation. The method can generate coherent intermediate images, predict image information of an explosive point of detonation of explosives, calculate the three-dimensional coordinates of the explosive point space by using a moment-based gravity center extraction algorithm, solve the technical problems of influence of the limited factors of the frame frequency of a high-speed camera on measurement of the explosive point space coordinates, solve the problems of large image storage amount, time consumption and inaccuracy in explosive point image searching, and improve the measurement precision of the explosive point coordinates.
Drawings
FIG. 1 is a station diagram of a detection system embodying the present invention;
FIG. 2 is a frame interpolation principle of the invention for a fried dot image;
FIG. 3 is a flow chart of the algorithm of the present invention;
FIG. 4 is a graph of the temporal relationship of the images of the frame interpolation algorithm of the present invention;
FIG. 5 is a diagram of the transformation relationship between the camera coordinate system and the world coordinate system according to the present invention.
Detailed Description
The present invention will now be described in further detail with reference to specific examples, which are intended to be illustrative, but not limiting, of the invention.
Example 1:
referring to fig. 1, a detection device for a spatial coordinate of a frying point comprises an infrared detection device, a sky screen target triggering device, a frying point image processing system, a Beidou time system device, two groups of test benches and at least two high-speed cameras; at least one high-speed camera is respectively erected on two sides of a trajectory by a tripod at the station distribution position of a safe region of an end point trajectory, rock mass protection is carried out, the pre-explosion range of a shell is positioned in the intersection detection view field region of the high-speed cameras on the two sides of the end point trajectory, an infrared detection device is distributed in the safe region of a theoretical explosion point of the end point trajectory by the tripod, rock mass protection is carried out, the pre-explosion point of the shell is positioned in the detection view field region of the infrared detection device, a sky screen target trigger device is distributed in the safe region below the pre-explosion point which is 300-500 meters away from the front end of the central position of the high-speed cameras on the two sides of the end point trajectory, at least two groups of test standard rods are arranged at the theoretical explosion point, the coordinates of the test standard rods are measured, and a system for processing images of the explosion points and a Beidou time system are distributed in the safe region outside the explosion point and provided with rock mass protection; the high-speed camera is respectively connected with the sky-curtain target triggering device, the explosion point image processing system and the Beidou time system device, and the infrared detection device and the Beidou time system device are connected with the explosion point image processing system.
The high-speed camera is used for synchronously shooting sequence image information of a target cannonball in an end point trajectory from a plurality of angles in a close range; the sky-screen target triggering device is used for providing uniform triggering signals for the high-speed cameras on two sides of the trajectory so as to ensure that the high-speed cameras are provided with accurate synchronous starting shooting signals when the cannonball flies over the sky-screen target triggering device, so that the high-speed cameras can accurately shoot image information of the cannonball before and after explosion, and the storage capacity of the image information of the high-speed cameras is reduced; the device comprises an infrared detection device, a test marker post and a high-speed camera, wherein the infrared detection device is used for capturing an infrared signal of a shell explosion point and transmitting the infrared signal to a explosion point image processing system to determine the explosion time information of the shell so as to quickly extract an accurate and reliable shell explosion point image; the bomb spot image processing system is used for acquiring bomb image information by image framing according to the bomb explosion time information provided by the infrared detection device for the target bomb sequence image information captured by the high-speed camera and judging the bomb image information; if the camera shoots the image of the explosion time point at the time point of the explosion of the cannonball, calculating the space coordinate of the explosion point by adopting the frame of image; if the camera does not shoot the image of the explosion time point at the time point of the explosion of the cannonball, extracting cannonball image information when a frame is not detonated before explosion and cannonball flare image information when a first frame appears flare after the cannonball explodes, acquiring explosion point image information of the first moment when the cannonball detonates by adopting an image frame interpolation algorithm and combining a cannonball explosion flare model and the cannonball explosion moment, and calculating the explosion point space three-dimensional coordinate and the explosion moment information of the first moment when the cannonball explodes by utilizing the explosion point image information.
Referring to fig. 1 to 5, a method for measuring a spatial coordinate of a fry spot using the apparatus for detecting a spatial coordinate of a fry spot includes the steps of:
step 1): arranging an infrared detection device, a backdrop target triggering device, a blast point image processing system, a Beidou time system device, two groups of test benchmarks and at least two high-speed cameras arranged at two sides of a terminal trajectory in a safe area of the terminal trajectory; mounting each device to form a detection device of the spatial coordinates of the explosion points;
the step 1) is specifically as follows:
respectively erecting at least one high-speed camera on two sides of a trajectory by using a tripod at the station distribution position of a safe region of an end point trajectory, performing rock mass protection, enabling a pre-explosion range of a shell to be positioned in an intersection detection view field region of the high-speed cameras on the two sides of the end point trajectory, distributing an infrared detection device in the safe region of a theoretical explosion point of the end point trajectory, performing rock mass protection, enabling the pre-explosion point of the shell to be positioned in the detection view field region of the infrared detection device, distributing a dome target trigger device in the safe region below the pre-explosion point at a distance of 300-500 meters away from the centers of the high-speed cameras on the two sides of the trajectory, placing at least two groups of test rods at the theoretical explosion point, measuring the coordinates of the test rods, distributing an explosion point image processing system and a Beidou time system outside the explosion point, and setting rock mass protection; the high-speed camera is respectively connected with the sky screen target triggering device, the explosion point image processing system and the Beidou time system device, and the infrared detection device and the Beidou time system device are connected with the explosion point image processing system.
Step 2): when a target shell passes through a detection area of a dome target trigger device, the dome target trigger device outputs a trigger signal, high-speed cameras on two sides of a trajectory are started to acquire real-time continuous high-frame frequency video images of the target shell, the acquired images are cached to obtain sequence image information of the target shell, and the obtained sequence image information of the target shell is sent to a blast point image processing system; and the sky screen target triggering device also starts the infrared detection device at the same time, and the infrared detection device starts to collect the shell explosion time information in real time and sends the collected shell explosion time information to the explosion point image processing system.
The step 2) is specifically as follows: when a target cannonball passes through a light curtain formed by a canopy target optical lens in a detection area of a canopy target trigger device, as the target cannonball shields a part of light, the luminous flux reaching the photosensitive surface of a photoelectric sensor on the canopy target optical lens is changed, the changed luminous flux is subjected to the processing of extraction, amplification, noise filtering and level conversion circuits through an analog circuit, and finally a TTL level signal with fixed pulse width is output to high-speed cameras on two sides of a trajectory, the high-speed cameras on the two sides of the trajectory are started to carry out real-time continuous high-frame-frequency video image acquisition on the target cannonball, the acquired images are cached to obtain target cannonball sequence image information, and the obtained target cannonball sequence image information is sent to a shot point image processing system; and the sky screen target triggering device also starts the infrared detection device at the same time, and the infrared detection device starts to collect the shell explosion time information in real time and sends the collected shell explosion time information to the explosion point image processing system.
Step 3): the bomb explosion point image processing system receives target bomb sequence image information sent by the high-speed camera and bomb explosion time information sent by the infrared detection device in real time, rapidly extracts bomb image information of a bomb explosion point area by adopting a video framing method according to the bomb explosion time information provided by the infrared detection device, judges whether the high-speed camera shoots an image of an explosion time point or not, and executes the following two operation modes;
the first method is as follows: if the high-speed camera judges that the time point of the explosion of the shell in the shell image information shoots the image of the explosion time point, the image of the explosion time point is a detonation point image Gd 'when the shell explodes' 0 (u e ,v e ,t 0 ) Then, a background subtraction and morphological filtering method is adopted to detect and identify the explosion point image information of the explosion moment of the cannonball and the corresponding moment T n0
The second method comprises the following steps: if the high-speed camera judges that the time point of the explosion of the cannonball in the cannonball image information does not shoot the image of the explosion time point, the cannonball explosion time information point obtained by the infrared detection device is utilized, and the background subtraction and shape filtering method is adopted to quickly extract the explosion time point from the cannonball image informationThe image information of the cannonball when the previous frame is not detonated, the image information of the cannonball flare when the first frame appears flare after the cannonball is exploded, and the corresponding time T of each frame n-1 、T n1
Then, calculating each pixel point of the interpolated frame image by adopting a frame mixing frame interpolation algorithm in the image frame interpolation algorithm and combining a shell explosion fireball expansion model to generate an intermediate frame image Gd 0 (u e ,v e ,t 0 ) Namely, the image information of the explosion point at the explosion moment of the cannonball;
the generated intermediate frame image is analyzed, and two situations exist: 1) After the image frames of the explosion point when the shell and the shell are detonated are mixed, no superposition or partial superposition exists, and the explosion point coordinate of the intermediate frame image is the intermediate point of the shell coordinate and the central coordinate of the explosion point image when the shell is detonated; 2) And after the image frames of the explosion point when the shell and the shell are detonated are mixed, the target of the shell is completely superposed with the flare image, and the explosion point coordinate of the intermediate frame image is the center coordinate of the explosion point image when the shell is detonated.
The step 3) is specifically as follows:
step 3): the explosion point image processing system receives target cannonball sequence image information sent by a high-speed camera and cannonball explosion time information sent by an infrared detection device in real time, quickly extracts the start and stop time of target cannonball video information before and after the detonation of a cannonball in the target cannonball sequence image information according to the cannonball explosion time information provided by the infrared detection device, and derives each frame JPEG image I (u) with time marks by adopting a video framing method e ,v e T), then quickly extracting cannonball image information of an explosion point area, judging the cannonball image information, judging whether an image of an explosion time point is shot by a high-speed camera or not, and executing the following two operation modes;
the first method is as follows: if the high-speed camera in the shell image information at the time point of shell explosion is judged to shoot the image at the explosion time point, the image at the explosion time point is a detonation point image Gd 'during shell explosion' 0 (u e ,v e ,t 0 ) Acquiring a previous frame image of the cannonball entering a field of view as a background image M bg (u e ,v e ,t 0 ) (ii) a Explosive point image Gd 'during detonation of cannonball with time marks' 0 (u e ,v e ,t 0 ) Background subtraction is carried out by adopting a background difference algorithm, and then the background subtraction processed detonation point image Gd 'of the multi-gray-level shell is detonated' 0 (u e ,v e ,t 0 ) Performing binarization processing, determining a threshold value by adopting a maximum inter-class variance method, setting the pixel value greater than or equal to the threshold value as 1, and setting the pixel value less than the threshold value as 0; then, a morphological filtering method is adopted to carry out detonation point image Gd 'on the shell subjected to binarization processing during detonation' 0 (u e ,v e ,t 0 ) Performing opening operation filtering treatment of corrosion and expansion, removing small particle noise, smoothing target boundary, and accurately extracting explosive point target or cannonball target and flare target without changing shape and area thereof to obtain explosive point image information Gd at the cannonball explosion time n0 (u e ,v e ,t n0 ) And corresponding time T n0
The second method comprises the following steps: if the camera judges that the time point of the explosion of the cannonball in the cannonball image information does not shoot the image of the explosion time point, the target cannonball sequence image information is quickly extracted from the cannonball image information by utilizing the cannonball explosion time information point obtained by the infrared detection device, and the previous frame image of the cannonball entering the field of view is obtained and is used as a background image M bg (u e ,v e ,t 0 ) (ii) a Background subtraction is carried out on the image information of the target cannonball sequence with the time marks by adopting a background difference algorithm, binarization processing is carried out on the image information of the target cannonball sequence with multiple gray levels after the background subtraction processing, a threshold value is determined by adopting a maximum inter-class variance method, the pixel point value which is greater than or equal to the threshold value is set as 1, and the pixel value which is smaller than the threshold value is set as 0; then, performing open operation filtering processing of firstly corroding and then expanding on the binarized target cannonball sequence image information by adopting a morphological filtering method, removing small-particle noise, smoothing the target boundary, accurately extracting a bomb point target or a cannonball target and a flare target without changing the shape and the area of the target cannonball sequence image information, and obtaining the cannonball image information Gd when the frame is not detonated before explosion n-1 (u e ,v e ,t n-1 ) And the shell flare image information Gd when flare appears in the first frame after the explosion of the shell n1 (u e ,v e ,t n1 ) And each frame corresponding time T n-1 、T n1
Then, the shell image Gd of the non-detonation previous frame after the morphological filtering processing n-1 (u e ,v e ,t n-1 ) And a cannonball flare image Gd when flare appears in the first frame after the cannonball explosion n1 (u e ,v e ,t n1 ) Substituting into an interpolation frame algorithm, combining with a shell explosion fireball expansion model, assuming that the weight of a frame before detonation is L-alpha/L, the weight of a first frame of image after detonation is alpha/L, multiplying two reference frames by respective weights, and adding to obtain an intermediate frame image Gd 0 (u e ,v e ,t 0 ) (ii) a The algorithm is as follows:
Figure BDA0003908900330000161
wherein, L is the distance between two frames of the original frame, and alpha is the relative distance between the frame before detonation and the inserted frame;
the frame insertion time is:
T n0 =T n-1
in the second method, the generated inter-frame image is analyzed, and there are two cases:
(1) If the cannonball and the flare image are overlapped or partially overlapped, the coordinates of the explosion point of the intermediate frame image are the intermediate point of the cannonball coordinates and the central pixel coordinates of the flare image; (2) And if the cannonball target is completely overlapped with the flare image, the coordinates of the explosion point of the intermediate frame image are the coordinates of the central pixel of the flare image.
Step 4): detonation Point image Gd 'of detonation of the Shell obtained in mode one' 0 (u e ,v e ,t 0 ) Or intermediate frame image Gd obtained by the second mode 0 (u e ,v e ,t 0 ) Computing the coordinates (u) of the explosion point using a moment-based barycentric coordinate extraction algorithm p0 ,v p0 )。
The step 4) is specifically as follows:
detonation Point image Gd 'of detonation of the Shell obtained in mode one' 0 (u e ,v e ,t 0 ) Or intermediate frame image Gd obtained by the second mode 0 (u e ,v e ,t 0 ) Computing a shot point coordinate (u) using a moment-based barycentric coordinate extraction algorithm p0 ,v p0 ) (ii) a Let the quality of each pixel in the region of the explosion point in the image be 1, i.e. the quality of each pixel is equal to its pixel value, (u) e ,v e ) For the coordinates of the image pixel, S is the area of the pixel region, the p + q order moment of the target can be expressed as:
Figure BDA0003908900330000162
where M is the moment of the image at different values of p, q, f (u) e ,v e ) Is the quality of one pixel; respectively calculating the zero order moment and the first order moment thereof, wherein the three conditions are as follows:
when p =0, q =0, the obtainable zero order moment M (0,0) is:
Figure BDA0003908900330000163
when p =1,q =0, the first moment M (0,1) is:
Figure BDA0003908900330000171
when p =0, q =1, the first moment M (1,0) has the value:
Figure BDA0003908900330000172
the barycenter of the target image can be calculated by using the zeroth order moment and the first order moment, and is used as (u) p0 ,v p0 ) And representing the coordinates of the frying point, wherein the solving algorithm of the coordinates of the frying point is as follows:
Figure BDA0003908900330000173
wherein M (1,0) represents the sum of the abscissas of all pixels of the bullet hole, M (0,1) represents the sum of the column coordinates of all pixels of the bullet hole, and M (0,0) represents the number of pixels contained in the bullet hole.
Step 5): resolving the internal and external calibration parameters of the camera according to the test benchmarking image to obtain system calibration data; by establishing an image pixel coordinate system, an image coordinate system, a camera coordinate system and a world coordinate system, combining the conversion relation among the coordinate systems, solving a space explosion point coordinate model, and obtaining an explosion point coordinate (u) p0 ,v p0 ) And substituting the space explosion point coordinate model with the space explosion point coordinate model to solve the space coordinate and the explosion time of the explosion point.
The step 5) is specifically as follows: solving a space explosion point coordinate model and bringing explosion point coordinates into the space explosion point coordinate model to solve three-dimensional explosion point coordinates:
assuming that the three-dimensional coordinate of the space explosion point P in the world coordinate system is (X) P ,Y P ,Z P ) The imaged image coordinate is (u) P ,v P ) (ii) a The high speed camera linear model can be expressed as:
Figure BDA0003908900330000174
the camera distortion model is as follows:
Figure BDA0003908900330000175
Figure BDA0003908900330000176
wherein,
Figure BDA0003908900330000177
considering the second-order radial distortion, the distortion coefficient is a 1 、a 2 (ii) a λ is a scale factor, (u) w ,v w ) For undistorted image coordinates, (R, T) are the extrinsic parameters of the camera, R and T are the rotation matrix and translation vector from the world coordinate system to the camera coordinate system, respectively, a is the camera intrinsic parameter matrix, which can be expressed as:
Figure BDA0003908900330000181
in the formula (u) 0 ,v 0 ) As principal point coordinates of an image coordinate system, f x 、f y Scale factors for the u-axis and v-axis, respectively, and α is a non-perpendicular factor for the u-axis and v-axis; high-speed camera calibration of 5 parameters f of internal parameter matrix of camera to be referenced x 、f y 、α、u 0 And v 0 And distortion coefficient a 1 、a 2
Before testing, two standard test benchmarks rotate in multiple directions within the range of the pre-explosion point of the cannonball, and a high-speed binocular camera is adopted to shoot moving images of the multiple standard test benchmarks at the pre-explosion point of the cannonball in different directions; resolving 5 parameters and a camera distortion coefficient calibrated by a camera according to an imaging relation of characteristic points on a standard test target on a binocular camera consisting of high-speed cameras on two sides;
the transformation relation from the pixel coordinate system to the world coordinate system is obtained by establishing an image pixel coordinate system, an image coordinate system, a camera coordinate system and the world coordinate system and combining the transformation relation among the coordinate systems as follows:
Figure BDA0003908900330000182
wherein Z is c Is 1,s as the coordinate axis tilt parameter, in the ideal case 0,A is the camera intrinsic parameter matrix, the orthogonal rotation matrix R is the cosine combination of the camera coordinate system with respect to the direction of the coordinate axis of the world coordinate system, and the translation matrix T = [ T ] 1 t 2 t 3 ] T Is the coordinate of the origin of the camera coordinate system under the world coordinate system; further combining the above formulaAnd calculating to obtain a conversion relation between the system pixel coordinate and the world coordinate system as follows:
Figure BDA0003908900330000183
order to
Figure BDA0003908900330000191
The above formula can be simplified to the following space fryer point coordinate model:
[X Y Z 1] T =C -1 [u v 1] T
in the formula, (X, Y, Z) is the solved coordinates of the space explosion point, and the unit is meter; (u, v) are pixel coordinates in pixels;
wherein, the coordinates (u) of the frying point obtained in the step 2) are used p0 ,v p0 ) And substituting the three-dimensional coordinates into the formula space explosion point coordinate model to obtain explosion time explosion point space three-dimensional coordinates (X, Y and Z).
The invention provides a detection device and a measurement method for explosion point space coordinates, which can rapidly extract the cannonball image information of an explosion point area from the cannonball sequence image information shot by a high-speed camera by adopting a video framing method based on the cannonball explosion time information provided by an infrared detection device, can directly obtain the explosion point image information by judging, and then can calculate the space three-dimensional coordinates of the explosion point in the air, thereby improving the working efficiency and reducing the labor intensity, or can rapidly extract the cannonball image information when the former frame before explosion is not detonated and the cannonball flare image information when the first frame appears flare after the cannonball explodes from the cannonball image information, thereby rapidly finding the explosion point coordinates, improving the working efficiency and reducing the labor intensity, simultaneously, fully utilizing the relation between the camera shooting sequence images in the explosion point forming process by utilizing a binocular high-speed camera detection mechanism, generating a more accurate first frame flare light image at the explosion point explosion time by adopting an image frame interpolation method, forming continuous frame images, combining binocular vision to detect and calculate the space three-dimensional coordinates of the explosion point, solving the problem that the explosion point information cannot be captured by the explosion initial time frame frequency limitation of the cannonball, thereby improving the calculation precision.
The device and the method for detecting the explosion point space coordinate solve the technical problem that in the prior art, the explosion light diffusion speed is high, the image information of the explosion fireball at the initial moment of explosion cannot be captured due to the limitation of the frame frequency of a high-speed camera, the image of the explosion fireball in the first frame after explosion is very large and even changed into irregular fireball, and the like, so that the calculation of the instantaneous coordinate of the detonation of the fireball has large deviation. The method can generate coherent intermediate images, predict image information of an explosive point of detonation of explosives, calculate the three-dimensional coordinates of the explosive point space by using a moment-based gravity center extraction algorithm, solve the technical problems of influence of the limited factors of the frame frequency of a high-speed camera on measurement of the explosive point space coordinates, solve the problems of large image storage amount, time consumption and inaccuracy in explosive point image searching, and improve the measurement precision of the explosive point coordinates.
The foregoing shows and describes the general principles and broad features of the present invention and advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims (7)

1. A detection device for a spatial coordinate of a shot point is characterized by comprising an infrared detection device, a sky-screen target triggering device, a shot point image processing system, a Beidou time system device, a test benchmark and at least two high-speed cameras; at least one high-speed camera is respectively erected on two sides of a trajectory by a tripod at the station distribution position of a safe region of an end point trajectory, rock mass protection is carried out, the pre-explosion range of a shell is positioned in the intersection detection view field region of the high-speed cameras on the two sides of the end point trajectory, an infrared detection device is distributed in the safe region of a theoretical explosion point of the end point trajectory by the tripod, rock mass protection is carried out, the pre-explosion point of the shell is positioned in the detection view field region of the infrared detection device, a sky screen target trigger device is distributed in the safe region below the pre-explosion point which is 300-500 meters away from the front end of the central position of the high-speed cameras on the two sides of the end point trajectory, a test marker rod is placed at the theoretical explosion point, the coordinates of the test marker rod are measured, and a system for processing images of the explosion point and a Beidou time system are distributed in the safe region outside the explosion point and provided with rock mass protection; the high-speed camera is respectively connected with the sky-curtain target triggering device, the explosion point image processing system and the Beidou time system device, and the infrared detection device and the Beidou time system device are connected with the explosion point image processing system.
2. The fryer point space coordinate detecting device of claim 1, wherein said test posts are at least two sets of test posts.
3. The explosion point space coordinate detecting device of claim 1, wherein the high-speed camera is used for synchronously shooting sequence image information of a target cannonball in an end point trajectory from a plurality of angles and close distances; the sky-screen target triggering device is used for providing uniform triggering signals for the high-speed cameras on two sides of the trajectory so as to ensure that the high-speed cameras are provided with accurate synchronous shooting starting signals when the cannonball flies over the sky-screen target triggering device, so that the high-speed cameras can accurately shoot image information of the cannonball in the time period before and after explosion, and the storage capacity of the image information of the high-speed cameras is reduced; the infrared detection device is used for capturing an infrared signal of an explosion point of the cannonball and transmitting the infrared signal to the explosion point image processing system to determine explosion moment information of the cannonball so as to quickly extract an accurate and reliable explosion point image of the cannonball; the test marker post is used for providing known coordinate points for the high-speed cameras on two sides of the trajectory before the test is started, and calibrating the internal and external parameters of the high-speed cameras and calculating the space coordinates after the test; the bomb spot image processing system is used for acquiring bomb image information by image framing according to the bomb explosion time information provided by the infrared detection device for the target bomb sequence image information captured by the high-speed camera and judging the bomb image information; if the camera shoots the image of the explosion time point at the time point of the explosion of the cannonball, the image is adopted to calculate the space coordinate of the explosion point; if the camera does not shoot the image of the explosion time point at the time point of the explosion of the cannonball, extracting cannonball image information when a frame is not detonated before explosion and cannonball flare image information when a first frame appears flare after the cannonball explodes, acquiring explosion point image information of the first moment when the cannonball detonates by adopting an image frame interpolation algorithm and combining a cannonball explosion flare model and the cannonball explosion moment, and calculating the explosion point space three-dimensional coordinate and the explosion moment information of the first moment when the cannonball explodes by utilizing the explosion point image information.
4. A fry spot space coordinate measuring method using the fry spot space coordinate detecting apparatus of any one of claims 1 to 3 comprising the steps of:
step 1): the bomb explosion point image processing system receives target bomb sequence image information sent by the high-speed camera and bomb explosion time information sent by the infrared detection device in real time, rapidly extracts bomb image information of a bomb explosion point area by adopting a video framing method according to the bomb explosion time information provided by the infrared detection device, judges whether the high-speed camera shoots an image of an explosion time point or not, and executes the following two operation modes;
the first method is as follows: if the high-speed camera judges that the time point of the explosion of the shell in the shell image information shoots the image of the explosion time point, the image of the explosion time point is a detonation point image Gd 'when the shell explodes' 0 (u e ,v e ,t 0 ) Then, detecting and identifying explosion point image information of the explosion moment of the cannonball and corresponding moment T by adopting a background subtraction and morphological filtering method n0
The second method comprises the following steps: if the fact that the camera does not shoot the image of the explosion time point at the time point of the explosion of the shell in the shell image information is judged, the shell explosion time information point obtained by an infrared detection device is utilized, and background subtraction and morphological filtering methods are adopted to quickly extract the shell image information before explosion when the explosion frame is not detonated and the shell flare image information of the first frame with flare after the explosion of the shell from the shell image informationInformation and each frame corresponding time T n-1 、T n1
Then, calculating each pixel point of the interpolated frame image by adopting a frame mixing frame interpolation algorithm in the image frame interpolation algorithm and combining a shell explosion fireball expansion model to generate an intermediate frame image Gd 0 (u e ,v e ,t 0 ) Namely, the image information of the explosion point at the explosion moment of the cannonball;
the generated intermediate frame image is analyzed, and two situations exist: 1) After the image frames of the explosion point when the shell and the shell are detonated are mixed, no superposition or partial superposition exists, and the explosion point coordinate of the intermediate frame image is the intermediate point of the shell coordinate and the central coordinate of the explosion point image when the shell is detonated; 2) After the image frames of the explosion points when the shell and the shell are detonated are mixed, the shell target is completely superposed with the flare image, and the explosion point coordinate of the intermediate frame image is the center coordinate of the explosion point image when the shell is detonated;
step 2): detonation Point image Gd 'of detonation of the Shell obtained in mode one' 0 (u e ,v e ,t 0 ) Or intermediate frame image Gd obtained by the second mode 0 (u e ,v e ,t 0 ) Computing the coordinates (u) of the explosion point using a moment-based barycentric coordinate extraction algorithm p0 ,v p0 );
Step 3): resolving the internal and external calibration parameters of the camera according to the test benchmarking image to obtain system calibration data; by establishing an image pixel coordinate system, an image coordinate system, a camera coordinate system and a world coordinate system, combining the conversion relation among the coordinate systems, solving a space explosion point coordinate model, and obtaining an explosion point coordinate (u) p0 ,v p0 ) And substituting the space explosion point coordinate model with the space explosion point coordinate model to solve the space coordinate and the explosion time of the explosion point.
5. The fry spot space coordinate measuring method of claim 4 further comprising, prior to step 1), the steps of:
step 4): arranging an infrared detection device, a backdrop target triggering device, a blast point image processing system, a Beidou time system device, two groups of test benchmarks and at least two high-speed cameras arranged at two sides of a terminal trajectory in a safe area of the terminal trajectory; mounting each device to form a detection device of the spatial coordinates of the explosion points;
step 5): when a target cannonball passes through a detection area of a dome target trigger device, the dome target trigger device outputs a trigger signal, high-speed cameras on two sides of a trajectory are started to acquire real-time continuous high-frame-frequency video images of the target cannonball, the acquired images are cached to obtain sequence image information of the target cannonball, and the obtained sequence image information of the target cannonball is sent to a blast point image processing system; and the sky screen target triggering device also starts the infrared detection device at the same time, and the infrared detection device starts to collect the information of the explosion moment of the cannonball in real time and sends the collected information of the explosion moment of the cannonball to the explosion point image processing system.
6. The method for measuring spatial coordinates of a frying point according to claim 5, wherein the step 4) is specifically as follows:
respectively erecting at least one high-speed camera on two sides of a trajectory by using a tripod at the station distribution position of a safe region of an end point trajectory, performing rock mass protection, enabling a pre-explosion range of a shell to be positioned in an intersection detection view field region of the high-speed cameras on the two sides of the end point trajectory, distributing an infrared detection device in the safe region of a theoretical explosion point of the end point trajectory, performing rock mass protection, enabling the pre-explosion point of the shell to be positioned in the detection view field region of the infrared detection device, distributing a dome target trigger device in the safe region below the pre-explosion point at a distance of 300-500 meters away from the centers of the high-speed cameras on the two sides of the trajectory, placing at least two groups of test rods at the theoretical explosion point, measuring the coordinates of the test rods, distributing an explosion point image processing system and a Beidou time system outside the explosion point, and setting rock mass protection; the high-speed camera is respectively connected with the sky screen target triggering device, the explosion point image processing system and the Beidou time system device, and the infrared detection device and the Beidou time system device are connected with the explosion point image processing system;
the step 5) is specifically as follows: when a target cannonball passes through a light curtain formed by a canopy target optical lens in a detection area of a canopy target trigger device, as the target cannonball shields a part of light, the luminous flux reaching the photosensitive surface of a photoelectric sensor on the canopy target optical lens is changed, the changed luminous flux is subjected to the processing of extraction, amplification, noise filtering and level conversion circuits through an analog circuit, and finally a TTL level signal with fixed pulse width is output to high-speed cameras on two sides of a trajectory, the high-speed cameras on the two sides of the trajectory are started to carry out real-time continuous high-frame-frequency video image acquisition on the target cannonball, the acquired images are cached to obtain target cannonball sequence image information, and the obtained target cannonball sequence image information is sent to a shot point image processing system; and the sky screen target triggering device also starts the infrared detection device at the same time, and the infrared detection device starts to collect the information of the explosion moment of the cannonball in real time and sends the collected information of the explosion moment of the cannonball to the explosion point image processing system.
7. The method for measuring spatial coordinates of a frying point according to claim 6, wherein the step 1) is specifically as follows:
step 1): the explosion point image processing system receives target cannonball sequence image information sent by a high-speed camera and cannonball explosion time information sent by an infrared detection device in real time, quickly extracts the start and stop time of target cannonball video information before and after the detonation of a cannonball in the target cannonball sequence image information according to the cannonball explosion time information provided by the infrared detection device, and derives each frame JPEG image I (u) with time marks by adopting a video framing method e ,v e T), then quickly extracting the cannonball image information of the explosion point area, judging the cannonball image information, judging whether the high-speed camera shoots the image of the explosion time point or not, and executing the following two operation modes;
the first method is as follows: if the camera shooting the image of the explosion time point at the time point of the explosion of the shell in the shell image information is judged, the image of the explosion time point is the explosion point image Gd 'when the shell explodes' 0 (u e ,v e ,t 0 ) Acquiring a previous frame image of the cannonball entering a field of view as a background image M bg (u e ,v e ,t 0 ) (ii) a Explosive point image Gd 'during detonation of cannonball with time marks' 0 (u e ,v e ,t 0 ) Background subtraction is carried out by adopting a background difference algorithm, and then the background subtracted multi-gray-level shell is detonated with a explosive point image Gd' 0 (u e ,v e ,t 0 ) Performing binarization processing, determining a threshold value by adopting a maximum inter-class variance method, setting the pixel value greater than or equal to the threshold value as 1, and setting the pixel value less than the threshold value as 0; then, a morphological filtering method is adopted to carry out detonation point image Gd 'on the shell subjected to binarization processing during detonation' 0 (u e ,v e ,t 0 ) Performing opening operation filtering treatment of corrosion and expansion, removing small particle noise, smoothing target boundary, and accurately extracting explosive point target or cannonball target and flare target without changing shape and area thereof to obtain explosive point image information Gd at the cannonball explosion time n0 (u e ,v e ,t n0 ) And corresponding time T n0
The second method comprises the following steps: if the fact that the camera does not shoot the image of the explosion time point at the time point of the explosion of the cannonball in the cannonball image information is judged, the cannonball explosion time information point obtained by the infrared detection device is utilized, target cannonball sequence image information is rapidly extracted from the cannonball image information, and the previous frame image of the cannonball entering the visual field is obtained and used as a background image M bg (u e ,v e ,t 0 ) (ii) a Background subtraction is carried out on the image information of the target cannonball sequence with the time marks by adopting a background difference algorithm, binarization processing is carried out on the image information of the target cannonball sequence with multiple gray levels after the background subtraction processing, a threshold value is determined by adopting a maximum inter-class variance method, the pixel point value which is greater than or equal to the threshold value is set as 1, and the pixel value which is smaller than the threshold value is set as 0; then, performing open operation filtering processing of firstly corroding and then expanding on the binarized target cannonball sequence image information by adopting a morphological filtering method, removing small-particle noise, smoothing the target boundary, accurately extracting a bomb point target or a cannonball target and a flare target without changing the shape and the area of the target cannonball sequence image information, and obtaining the cannonball image information Gd when the frame is not detonated before explosion n-1 (u e ,v e ,t n-1 ) And the shell flare image information Gd when the flare appears in the first frame after the explosion of the shell n1 (u e ,v e ,t n1 ) And each frame corresponding time T n-1 、T n1
Then, the shell image Gd of the non-detonation previous frame after the morphological filtering processing n-1 (u e ,v e ,t n-1 ) And a cannonball flare image Gd when flare appears in the first frame after the cannonball explosion n1 (u e ,v e ,t n1 ) Substituting into an interpolation frame algorithm, combining with a shell explosion fireball expansion model, assuming that the weight of a frame before detonation is L-alpha/L, the weight of a first frame of image after detonation is alpha/L, multiplying two reference frames by respective weights, and adding to obtain an intermediate frame image Gd 0 (u e ,v e ,t 0 ) (ii) a The algorithm is as follows:
Figure FDA0003908900320000061
wherein, L is the distance between two frames of the original frame, and alpha is the relative distance between the frame before detonation and the inserted frame;
the frame insertion time is:
T n0 =T n-1
in the second method, the generated inter-frame image is analyzed, and there are two cases:
(1) If the cannonball and the flare image are overlapped or partially overlapped, the coordinates of the explosion point of the intermediate frame image are the intermediate point of the cannonball coordinates and the central pixel coordinates of the flare image; (2) If the cannonball target is completely overlapped with the flare image, the coordinates of the explosion point of the intermediate frame image are the coordinates of the central pixel of the flare image;
the step 2) is specifically as follows:
detonation Point image Gd 'of detonation of the Shell obtained in mode one' 0 (u e ,v e ,t 0 ) Or intermediate frame image Gd obtained by the second mode 0 (u e ,v e ,t 0 ) Computing the coordinates (u) of the explosion point using a moment-based barycentric coordinate extraction algorithm p0 ,v p0 ) (ii) a Let the mass of each pixel in the region of a fried dot in the image be 1, i.e. each pixelIs equal to its pixel value, (u) e ,v e ) Is the coordinates of the image pixel, and S is the area of the pixel region, the p + q moment of the target can be expressed as:
Figure FDA0003908900320000062
where M is the moment of the image at different values of p, q, f (u) e ,v e ) Is the quality of one pixel; respectively calculating the zero order moment and the first order moment thereof, wherein the three conditions are as follows:
when p =0, q =0, the obtainable zero order moment M (0,0) is:
Figure FDA0003908900320000071
when p =1,q =0, the first moment M (0,1) is:
Figure FDA0003908900320000072
when p =0,q =1, the first moment M (1,0) has the value:
Figure FDA0003908900320000073
the center of gravity of the target image can be calculated by using the zero order moment and the first order moment, and the center of gravity is calculated by using (u) p0 ,v p0 ) And representing the coordinates of the frying point, wherein the solving algorithm of the coordinates of the frying point is as follows:
Figure FDA0003908900320000074
wherein M (1,0) represents the sum of the abscissa of all pixels of the bullet hole, M (0,1) represents the sum of the column coordinates of all pixels of the bullet hole, and M (0,0) represents the number of pixels contained in the bullet hole;
the step 3) is specifically as follows: solving a space explosion point coordinate model and bringing explosion point coordinates into the space explosion point coordinate model to solve explosion point space three-dimensional coordinates:
the three-dimensional coordinate of the space explosion point P in the world coordinate system is assumed to be (X) P ,Y P ,Z P ) The imaged image coordinate is (u) P ,v P ) (ii) a The high speed camera linear model can be expressed as:
Figure FDA0003908900320000075
the camera distortion model is as follows:
Figure FDA0003908900320000076
Figure FDA0003908900320000077
wherein,
Figure FDA0003908900320000078
considering the second-order radial distortion, the distortion coefficient is a 1 、a 2 (ii) a λ is a scale factor, (u) w ,v w ) For undistorted image coordinates, (R, T) are extrinsic parameters of the camera, R and T are the rotation matrix and translation vector from the world coordinate system to the camera coordinate system, respectively, a is the camera intrinsic parameter matrix, which can be expressed as:
Figure FDA0003908900320000081
in the formula (u) 0 ,v 0 ) As principal point coordinates of an image coordinate system, f x 、f y Scale factors for the u-axis and v-axis, respectively, and α is a non-perpendicular factor for the u-axis and v-axis; high-speed camera calibrating 5 parameters f of internal parameter matrix of reference camera x 、f y 、α、u 0 And v 0 And distortion coefficient a 1 、a 2
Before testing, two standard test benchmarks rotate in multiple directions within the range of the pre-explosion point of the cannonball, and a high-speed binocular camera is adopted to shoot moving images of the multiple standard test benchmarks at the pre-explosion point of the cannonball in different directions; according to the imaging relationship of the characteristic points on the standard test benchmarking on a binocular camera consisting of high-speed cameras on two sides, 5 parameters and a camera distortion coefficient calibrated by the camera are solved;
the transformation relation from the pixel coordinate system to the world coordinate system is obtained by establishing an image pixel coordinate system, an image coordinate system, a camera coordinate system and the world coordinate system and combining the transformation relation among the coordinate systems as follows:
Figure FDA0003908900320000082
wherein Z is c Is 1,s as the coordinate axis tilt parameter, in the ideal case 0,A is the camera intrinsic parameter matrix, the orthogonal rotation matrix R is the cosine combination of the camera coordinate system with respect to the direction of the coordinate axis of the world coordinate system, and the translation matrix T = [ T ] 1 t 2 t 3 ] T Is the coordinate of the origin of the camera coordinate system under the world coordinate system; by further solving the above equation, the conversion relationship between the system pixel coordinate and the world coordinate system can be obtained as follows:
Figure FDA0003908900320000083
order to
Figure FDA0003908900320000084
The above formula can be simplified to the following spatial fryer coordinates model:
[X Y Z 1] T =C -1 [u v 1] T
in the formula, (X, Y, Z) is the solved coordinates of the space explosion point, and the unit is meter; (u, v) are pixel coordinates in pixels;
wherein, the frying point coordinate (u) obtained in the step 2) is used p0 ,v p0 ) And substituting the three-dimensional space coordinates into the upper formula space explosion point coordinate model to obtain explosion time explosion point space three-dimensional coordinates (X, Y and Z).
CN202211316441.3A 2022-10-26 2022-10-26 Detection device and measurement method for spatial coordinates of explosion points Pending CN115585740A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117974967A (en) * 2024-03-28 2024-05-03 沈阳长白电子应用设备有限公司 Fried spot position measurement method based on image identification positioning

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117974967A (en) * 2024-03-28 2024-05-03 沈阳长白电子应用设备有限公司 Fried spot position measurement method based on image identification positioning

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