KR102494973B1 - Method and Apparatus for Measuring Impact Information of Guided Air Vehicle - Google Patents

Abstract

Disclosed is a method for measuring impact information of a guided flight vehicle and an apparatus therefor.
A method for measuring impact information of a guided vehicle according to an embodiment of the present invention includes an initial coordinate measuring step of measuring the coordinates of a target and the coordinates of an image capture device installed at a predetermined distance and angle based on the center of the target; When the guided vehicle lands on the ground, an image capture step of acquiring an image of the impact of the guided vehicle with respect to the location of the impact from the image capture device; a pixel coordinate extraction step of extracting image pixel coordinates for the entry point and the point of impact of the guided vehicle based on the image of the impact; and calculating a first inclination angle based on the image pixel coordinates, and calculating a second inclination angle based on the distortion pixel coordinates calculated using a predetermined initial entry value and an initial impact angle, wherein the first inclination angle and the second inclination angle are calculated. A measurement processing step of generating impact information including a final entry angle and a final impact angle using the inclination angle may be included.

Description

Method and Apparatus for Measuring Impact Information of Guided Air Vehicle

The present invention relates to a method for measuring impact information of a guided vehicle and an apparatus therefor.

The contents described in this section simply provide background information on the embodiments of the present invention and do not constitute prior art.

In general, when developing a system for a guided flight vehicle, test evaluation results such as flight trajectory and impact accuracy are obtained and verified while measuring equipment is installed on the guided flight vehicle. However, when a live-fire test is performed on mass-produced guided vehicles after the development of the system for the guided vehicles is completed, the measurement of the approach angle and impact angle of the guided vehicle to the target is difficult because the remote measurement equipment is not mounted on the guided vehicle. impossible.

The approach angle of the guided vehicle means the angle at which the guided vehicle enters the target plane, and it is checked whether or not the guided vehicle is flying in a pre-planned path to avoid a feature or structure around the target. The impact angle of the guided vehicle is an important performance evaluation item related to the effect diagram, which is the inclination angle formed by the speed vector of the guided vehicle when it hits the ground and the plane of the target.

In general, in order to measure the impact point in the test of a guided flight vehicle on a fixed ground target, the impact position is obtained by various methods using images, GPS coordinate measurement, and navigation information (position) measured by measuring equipment in the projectile. In this way, there are prior patents for calculating the position of the impact point of the guided vehicle, such as Korean Patent Registration No. 10-1624416 and Korean Patent Registration No. 10-1116156, but conventionally, only the position of the impact point is calculated, and the approach angle and impact angle is difficult to calculate.

It is difficult to verify the approach angle and impact angle in a live-fire test of a guided aircraft without expensive remote transmission/reception equipment (remote measurement equipment), and technology for systems and methods for extracting only the impact position using various methods such as video There is a limitation in performance evaluation as it is impossible to calculate the approach angle and impact angle of the guided flight vehicle.

The present invention calculates the first inclination angle of the guided vehicle based on the impact image of the guided vehicle, calculates the second inclination angle of the guided vehicle based on the initial set value, and uses the first inclination angle and the second inclination angle to determine the inclination angle of the guided vehicle. A main object of the present invention is to provide a method for measuring impact information of a guided vehicle that generates impact information including a final approach angle and a final impact angle, and a device therefor.

According to one aspect of the present invention, a method for measuring impact information of a guided vehicle to achieve the above object includes measuring the coordinates of a target and the coordinates of an image capture device installed at a predetermined distance and angle based on the center of the target. coordinate measurement step; When the guided vehicle lands on the ground, an image capture step of acquiring an image of the impact of the guided vehicle with respect to the location of the impact from the image capture device; a pixel coordinate extraction step of extracting image pixel coordinates for the entry point and the point of impact of the guided vehicle based on the image of the impact; and calculating a first inclination angle based on the image pixel coordinates, and calculating a second inclination angle based on the distortion pixel coordinates calculated using a predetermined initial entry value and an initial impact angle, wherein the first inclination angle and the second inclination angle are calculated. A measurement processing step of generating impact information including a final entry angle and a final impact angle using the inclination angle may be included.

In addition, according to another aspect of the present invention, the guided vehicle measuring device for achieving the above object is an initial coordinate for measuring the coordinates of a target and the coordinates of an image capture device installed at a preset distance and angle based on the center of the target. measuring part; When the guided vehicle lands on the ground, an impact image acquisition unit for acquiring an image of the impact of the guided vehicle with respect to the location of the impact from the image capture device; a pixel coordinate extraction unit for extracting image pixel coordinates of the entry point and the point of impact of the guided vehicle based on the image of the impact; and calculating a first inclination angle based on the image pixel coordinates, and calculating a second inclination angle based on the distortion pixel coordinates calculated using a predetermined initial entry value and an initial impact angle, wherein the first inclination angle and the second inclination angle are calculated. It may include a measurement processing unit that generates impact information including a final entry angle and a final impact angle using the inclination angle.

As described above, the present invention can extract the approach angle and impact angle, which are performance evaluation parameters of the guided vehicle, from image information obtained using a plurality of cameras installed on the ground in a live shooting test of the guided vehicle without remote measurement equipment. It works.

1 is a diagram for explaining the operating concept of a guided vehicle measurement system according to an embodiment of the present invention.
2 is a block diagram schematically showing a guided vehicle measurement system according to an embodiment of the present invention.
3 and 4 are flowcharts for explaining a method for measuring impact information of a guided vehicle according to an embodiment of the present invention.
5 is an exemplary view showing images of an impact at an entry point and a point of impact according to an embodiment of the present invention.
6 is an exemplary diagram showing an inclination angle at which a guided flight vehicle lands according to an embodiment of the present invention.
7 is a diagram for explaining a relationship between coordinate systems for measuring a guided vehicle according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description will be omitted. In addition, although preferred embodiments of the present invention will be described below, the technical idea of the present invention is not limited or limited thereto and can be modified and implemented in various ways by those skilled in the art. Hereinafter, a method for measuring impact information of a guided vehicle proposed in the present invention and an apparatus therefor will be described in detail with reference to the drawings.

The present invention provides a system and method for calculating an angle of impact and an approach angle using image information of a plurality of cameras installed on a landing site during a test of a guided vehicle landing on a ground target.

In the present invention, it is assumed that the landing angle and approach angle of the guided vehicle are not equipped with remote measurement equipment capable of transmitting navigation information (position, speed, attitude, etc.) representing the flight information of the guided vehicle to the ground.

1 is a diagram for explaining the operating concept of a guided vehicle measurement system according to an embodiment of the present invention.

In general, when developing a system for a guided flight vehicle, test evaluation results such as flight trajectory and impact accuracy are obtained and verified while measuring equipment is installed on the guided flight vehicle. However, when a live-fire test is performed on mass-produced guided vehicles after the development of the system for the guided vehicles is completed, the measurement of the approach angle and impact angle of the guided vehicle to the target is difficult because the remote measurement equipment is not mounted on the guided vehicle. impossible.

Accordingly, the guided vehicle measurement system 10 according to an embodiment of the present invention generates impact information on the approach angle and impact angle of the guided vehicle using image information obtained through a plurality of cameras installed in the impact area.

Referring to FIG. 1 , when a guided vehicle launched from the ground or in the air lands on a target installed on the ground, the guided vehicle measurement system 10 acquires images of impact from a plurality of cameras installed in the area of impact. The number of cameras installed in the guided vehicle measurement system 10 is not specifically limited, but is preferably at least three.

In the guided flight vehicle measurement system 10, cameras C1, C2, and C3 are installed at a certain distance and angle based on the center O of the installed target to capture an impact image. In addition, in the guided vehicle measurement system 10, a specific time point (entry time point) at which the guided vehicle is clearly identified in the photographed image is defined as t1, and a specific point in time (impact point) at which the vehicle lands on the ground is defined as t2. In the guided vehicle measurement system 10, the entry position of the guided vehicle at the point of entry is defined as P _t1 , and the impact position of the guided vehicle at the point of impact is defined as P _t2 .

2 is a block diagram schematically showing a guided vehicle measurement system according to an embodiment of the present invention.

The guided vehicle measurement system 100 according to this embodiment includes an image capture device 200 and a guided vehicle measurement device 300 . The image capture device 200 includes a plurality of cameras 210, 220, and 230. In addition, the guided vehicle measurement device 300 includes an initial coordinate measurement unit 310, an impact image acquisition unit 320, a pixel coordinate extraction unit 330, and a measurement processing unit 340. The guided vehicle measurement system 100 of FIG. 1 is according to an embodiment, and all blocks shown in FIG. 1 are not essential components, and in another embodiment, some blocks included in the guided vehicle measurement system 100 are added. , may be changed or deleted.

The guided vehicle measurement system 100 uses the image capture device 200 installed in the landing site to capture an image of a guided vehicle landing on a ground target, and calculates an approach angle and an angle of impact of the guided vehicle based on the image of the impact. Generates impact information including

The image capture device 200 refers to a device that is installed at the landing site and captures an image of the guided flight vehicle's landing.

Here, the image capture device 200 may include a plurality of cameras 210 , 220 , and 230 . Each of the plurality of cameras 210, 220, and 230 is installed at a predetermined distance and angle based on the center of the target installed in the landing site.

The image capturing device 200 according to the present embodiment may include three cameras such as the first camera 210, the second camera 220, and the third camera 230, but is not necessarily limited thereto, and the camera The number of can be changed.

The image capture device 200 transmits the photographed image of the impact to the guided vehicle measuring device 300 . Here, the impact image may be a two-dimensional image or an image including at least one frame.

The guided vehicle measuring device 300 calculates the first inclination angle of the guided vehicle based on the impact image of the guided vehicle, calculates the second inclination angle of the guided vehicle based on the initial setting value, and calculates the first inclination angle and the second inclination angle. It generates impact information including the final approach angle and final impact angle of the guided flight vehicle. Hereinafter, each of the components included in the guided vehicle measuring device 300 will be described.

The initial coordinate measurement unit 310 performs an operation of measuring the initial coordinates of a pre-installed target and the image capture device 200 .

The initial coordinate measurement unit 310 measures initial coordinates, such as the coordinates of the target and the coordinates of the image capture device 200 installed at a preset distance and angle based on the center of the target. Here, the initial coordinates are preferably GPS coordinates.

The initial coordinate measurement unit 310 may measure the initial coordinates based on the coordinates measured by a preset sensor or navigation device, but is not necessarily limited thereto, and coordinates measured by the user or coordinates measured from an external measurement device It is also possible to measure the initial coordinates by receiving .

The initial coordinates measured by the initial coordinate measuring unit 310 may include target-related coordinates, coordinates for each of at least one camera included in the image capture device 200, installation angle, and the like.

When the guided vehicle lands on the ground, the impact image acquisition unit 320 acquires an image of the impact of the guided vehicle with respect to the location of the impact from the image capture device 200 .

The impact image acquisition unit 320 may acquire an impact image of the guided flight vehicle for measuring the impact position and store the obtained impact image. Here, the image of the impact is preferably stored in the guided vehicle measuring device 300, but is not necessarily limited thereto, and may be stored in a separate storage device, database, cloud, or the like.

Here, the impact image is preferably a two-dimensional image, and may include at least one image captured by each of at least one camera included in the image capture device 200 .

The pixel coordinate extractor 330 extracts image pixel coordinates of the guided vehicle based on the image of the guided vehicle's impact.

The pixel coordinate extraction unit 330 extracts image pixel coordinates for each of the entry point and the point of impact of the guided flight vehicle from the impact image.

The pixel coordinate extraction unit 330 extracts pixel coordinates of the first image at the first viewpoint and pixel coordinates of the second image at the second viewpoint from the impact image. Here, the first image pixel coordinates are coordinates extracted at the point of entry of the guided vehicle, and the second image pixel coordinates are coordinates extracted at the point of impact of the guided vehicle. For example, the pixel coordinate extractor 330 extracts (x _p1 , y _p1 ) the pixel coordinates of the first image at time t1 (entry point) in the impact image, and extracts the pixel coordinates of the second image at time t2 (impression point). Image pixel coordinates can be extracted as (x _p2 , y _p2 ).

The measurement processing unit 340 calculates a first inclination angle based on image pixel coordinates, and calculates a second inclination angle based on the distortion pixel coordinates calculated using a preset initial entry value and an initial impact angle. The measurement processing unit 340 generates impact information including a final entry angle and a final impact angle using the first and second inclination angles.

Hereinafter, detailed steps for calculating the final entry angle and the final impact angle in the measurement processing unit 340 will be described.

First, the measurement processing unit 340 performs a step of calculating a first inclination angle.

The measurement processing unit 340 converts the target coordinate system and calculates a first inclination angle using pixel coordinates of the first image at the first viewpoint and pixel coordinates of the second image at the second viewpoint.

The measurement processing unit 340 calculates a first inclination angle formed by a vector connecting the entry point of pixel coordinates of the first image and the point of impact of pixel coordinates of the second image with respect to the horizontal line of the ground in the impact image. Here, it is preferable that the first inclination angle is always a positive value.

An operation of calculating the first inclination angle in the measurement processing unit 340 according to the present embodiment corresponds to the operation described in step S420 of FIG. 4 .

Next, the measurement processing unit 340 performs a step of calculating the second inclination angle.

The measurement processing unit 340 converts the impact coordinate system and calculates first spatial coordinates and second spatial coordinates based on the preset initial entry value and the initial impact angle. Here, the measurement processing unit 340 estimates first spatial coordinates and second spatial coordinates obtained by converting the impact coordinate system into the target coordinate system using the initial entry value and the initial impact angle.

Thereafter, the measurement processing unit 340 calculates a second tilt angle by converting the first spatial coordinates and the second spatial coordinates into normalized image coordinates and then calculating the first distorted pixel coordinates and the second distorted pixel coordinates.

The measurement processing unit 340 converts the first spatial coordinates and the second spatial coordinates based on the normalized image coordinate system, and then calculates first distorted pixel coordinates for replacing the coordinates of the first view through pixel image coordinate system conversion, and second Second distortion pixel coordinates for replacing the coordinates of the viewpoint are calculated.

The measurement processing unit 340 calculates a second inclination angle formed by a vector connecting the first and second distortion pixel coordinates.

An operation of calculating the second inclination angle in the measurement processing unit 340 according to the present embodiment corresponds to the operations described in steps S430 to S470 of FIG. 4 .

Finally, the measurement processing unit 340 performs the impact information measurement processing step.

The measurement processing unit 340 generates impact information including a final entry angle and a final impact angle by using an objective function based on the first and second tilt angles.

The measurement processor 340 generates impact information including the final entry angle and the final impact angle by using an objective function that minimizes the square of the residual between the first and second tilt angles.

When the calculated value of the objective function is greater than or equal to a predetermined tolerance, the measurement processing unit 340 repeatedly performs an operation of calculating a new second inclination angle by updating the initial entry value and the initial impact angle. Thereafter, the measurement processing unit 340 calculates a final entry angle and a final impact angle that minimize the residual square of the first inclination angle and the new second inclination angle.

An operation of generating impact information including a final approach angle and a final impact angle in the measurement processing unit 340 according to the present embodiment corresponds to operations described in steps S480 to S490 of FIG. 4 .

3 and 4 are flowcharts for explaining a method for measuring impact information of a guided vehicle according to an embodiment of the present invention.

3 is a flowchart schematically illustrating a method of measuring impact information of a guided vehicle in the guided vehicle measuring device 300.

The guided vehicle measuring device 300 measures initial coordinates including target center coordinates for the previously installed target and the image capture device 200 and coordinates of each camera included in the image capture device 200 (S310). Here, the initial coordinates are preferably GPS coordinates.

When the guided vehicle lands on the ground, the guided vehicle measuring device 300 measures the location of the impact and acquires an image of the impact of the measured location (S320 and S330). Here, the impact image is preferably a two-dimensional image.

The guided vehicle measuring device 300 extracts image pixel coordinates (image coordinates) for each entry point and impact point of the guided vehicle based on the image of the guided vehicle's impact (S340).

The guided vehicle measuring device 300 generates impact information including an approach angle and an impact angle of the guided vehicle using image pixel coordinates, initial settings, and the like (S350).

The guided vehicle measuring device 300 calculates the first inclination angle of the guided vehicle based on the image pixel coordinates extracted from the impact image, calculates the second inclination angle of the guided vehicle based on the initial setting value, and calculates the first inclination angle and the second inclination angle of the guided vehicle. 2 Calculate the final approach angle and final impact angle of the guided flight vehicle using the inclination angle.

4 is a flowchart showing a method of measuring impact information of a guided vehicle in the guided vehicle measuring device 300 in detail.

The guided vehicle measuring device 300 measures the initial coordinates of the target and the camera installed at a predetermined distance and angle based on the target point (S410). The guided vehicle measuring device 300 may receive center coordinates of the target and camera coordinates.

In addition, the guided vehicle measuring device 300 may receive coordinates of an impact point, image pixel coordinates, etc. extracted through an image of the impact after the guided vehicle lands. Specifically, the guided vehicle measuring device 300 measures the impact position after the guided vehicle lands on the ground, and stores an image of the impact. The guided vehicle measuring device 300 extracts image pixel coordinates of the entry point and the point of impact of the guided vehicle from the two-dimensional image of the camera. The guided vehicle measuring device 300 determines the first image pixel coordinates (x _p1 , y p1 ) at the first viewpoint (entry point) and the second image pixel coordinates (x _p2 , y _p1 ) at the second viewpoint (impact point) in the impact image y _p2 ) is extracted.

The guided vehicle measuring device 300 calculates the installation angle of the camera, performs coordinate system conversion, and calculates the first inclination angle by using the pixel coordinates of the first image at the first viewpoint and the pixel coordinates of the second image at the second viewpoint. Calculate (S420).

In step S420, the guided vehicle measuring device 300 performs a step of converting GPS coordinates into a target coordinate system.

The guided vehicle measuring device 300 converts the target center, camera, and impact point measured on the ground into WGS 84 GPS (latitude, altitude, and longitude) into ECEF (Earth-centered coordinates).

The guided vehicle measuring device 300 is a North-East-Down (NED) coordinate system in which the center of the target is the origin in the converted earth-centered coordinate axis, and the X-axis is the true north direction, the Y-axis is the east direction, and the Z-axis is the ground direction. Calculate the target and camera reference points by constructing a transformation matrix. For example, the target origin is defined as O = (0, 0, 0), the camera position is defined as P _C = (X _C , Y _C , Z _C ), and the impact position is defined as P _ip = (X _ip , Y _ip , Z _ip ).

After that, the guided vehicle measuring device 300 may calculate the camera installation angle. The guided vehicle measuring device 300 may calculate the true north standard installation angle using [Equation 1] at the measured camera position.

(ψ _c : camera installation angle, X _C : x coordinate of camera position, Y _C : y coordinate of camera position)

을 이용하여 계산될 수 있다. Then, the guided vehicle measuring device 300 calculates a transformation matrix between the target coordinate system and the camera coordinate system. In the guided vehicle measuring device 300, conversion of the camera coordinate system from the target coordinate system is a translational movement (T _{o / c} ) and a rotation matrix

can be calculated using

은 3-2-1 변환(Z-Y-X) 법칙을 따르며, 병진이동 및 회전행렬은 [수학식 2]와 같이 정의될 수 있다. rotation matrix

follows the 3-2-1 transformation (ZYX) rule, and the translation and rotation matrices can be defined as in [Equation 2].

: 회전행렬)(ψ _c : camera installation angle, P _C : camera position coordinates,

: rotation matrix)

Thereafter, the guided vehicle measuring device 300 performs an operation of calculating a first inclination angle using the image pixel coordinates.

The guided flight vehicle measuring device 300 is the first image pixel coordinates (x _p1 , y _p1 ) of the entry point at the first point of view and the second image pixel coordinates (x _p2 , y _p2 ) of the impact point at the second point of view. The first inclination angle θ _m is calculated using Here, the first inclination angle means an angle formed by a vector connecting an entry point and an impact point with respect to a horizontal line of the ground in image coordinates in a 2D impact image. The guided vehicle measuring device 300 may calculate the first inclination angle θ _m using Equation 3. Here, y' _p1 = -y _p1 and y' _p2 = -y _p2 are defined.

(θ _m : 1st tilt angle, x _p1 : x coordinate of pixel coordinates of 1st image, y _p1 : y coordinate of pixel coordinates of 1st image, x _p2 : x coordinate of pixel coordinates of 2nd image, y _p2 : 2nd image y coordinate in pixel coordinates, y' _p1 : - y _p1 , y' _p2 : - y _p2 )

The guided flight vehicle measuring device 300 sets a preset initial entry value (λ ₀ ) and an initial impact angle (γ ₀ ) for optimal function calculation (S430).

The guided vehicle measuring device 300 performs an operation of converting the unit vector of the impact coordinate system into the target coordinate system (S440).

The impact coordinate system is a coordinate system rotated by the entry angle and impact angle with respect to the target coordinate system with the impact position as the origin, and the X-axis direction is parallel to the velocity vector of the guided flight vehicle.

In the guided vehicle measuring device 300, the 3D coordinates (P ₂ ) of the second time point (t2, point of impact) are measured, but the 3D coordinates (P ₁ ) of the first time point (t1, entry point) are measured. this is impossible To solve this problem, the unit vector [1,0,0] of the impact coordinate system is assumed and applied as the first point of time (t1, entry point). This means that even if the 3D coordinates of the first point in time (t1, entry point) are not known, the unit vector is parallel to the line segment connecting the coordinates of the first point in time (t1, entry point) and the second point in time (t2, impact point), and the line segment Since it is located on the top, the calculated inclination angle is the same.

In the guided flight vehicle measuring device 300, the 3-dimensional coordinates (P ₂ , second space coordinates) of the second point of view (t2, point of impact) and the 3-dimensional coordinates (P ₁ , the first point of entry) of the first point of time (t1, point of entry) 1 spatial coordinate) is calculated by [Equation 4]. Here, the 3D coordinates (first spatial coordinates) of the first viewpoint t1 and the 3D coordinates (second spatial coordinates) of the second viewpoint t2 refer to coordinates based on the target coordinate system.

(P ₁ : 3-dimensional coordinates of the first time point t1, P ₂ : 3-dimensional coordinates of the second time point t2, λ ₀ : initial entry value, γ ₀ : initial impact angle)

Thereafter, the guided vehicle measuring device 300 converts the first spatial coordinates and the second spatial coordinates of the target coordinate system into normalized image coordinates (S450).

Projection geometry is a geometry that handles projection, and an image acquired by a camera is a projection of points in a three-dimensional space onto a plane of image pixels. If you connect the camera focal point and the projected point, a projection line comes out, and all three-dimensional points on the projection line are projected to the same point. This projection relationship corresponds to the concept of homogeneous coordinates, which expresses (x,y) as (wx, wy, w) for an arbitrary non-zero constant w, ignoring scale.

The conversion from the first spatial coordinates and the second spatial coordinates in the 3D space to the normalized image coordinates may be performed as in [Equation 5]. Here, the focal length f corresponds to 1.

The first normalized image coordinates and the second normalized image coordinates obtained by transforming the first spatial coordinates and the second spatial coordinates using [Equation 5] may be defined as in [Equation 6].

The guided vehicle measuring device 300 converts normalized image coordinates into distorted pixel coordinates.

The guided vehicle measuring device 300 converts the first normalized image coordinates and the second normalized image coordinates into distorted first distorted pixel coordinates and second distorted pixel coordinates (S460).

The normalized image coordinate is a geometric coordinate system in which the effects of camera parameters are removed. Camera internal parameters and lens distortion parameters can be obtained through camera calibration. Camera calibration is generally dealt with in the field of photometry/computer vision, and various application technologies and theories exist depending on the purpose, so a detailed description is omitted here. The presented mathematical model for camera distortion is not necessarily limited thereto, and can be changed to various models.

The guided vehicle measuring device 300 calculates distorted normalized image coordinates as shown in [Equation 7].

를 픽셀좌표로 변환하여 왜곡된 왜곡 픽셀좌표

를 계산한다. Thereafter, the guided vehicle measuring device 300 uses [Equation 8] to distort the normalized image coordinates.

Distorted pixel coordinates by converting to pixel coordinates

Calculate

와 제2 시점(t2)에서의 탄착점 좌표를 대체한 제2 왜곡 픽셀좌표

를 추출한다. 여기서,

,

로 정의한다.The guided vehicle measuring device 300 uses [Equation 8] to obtain the first distorted pixel coordinates replacing the coordinates of the entry point at the first time point t1.

and second distortion pixel coordinates replacing the coordinates of the impact point at the second time point t2

extract here,

,

is defined as

Thereafter, the guided vehicle measuring device 300 calculates a second inclination angle θ _est based on the converted distortion pixel coordinates (S470).

와 제2 시점(t2)에서의 탄착점 좌표를 대체한 제2 왜곡 픽셀좌표

를 이용하여 제2 경사각(θ_est)을 계산한다. 여기서, 제2 경사각(θ_est)은 2 차원 영상좌표에서 지면의 수평선에 대해 제1 왜곡 픽셀좌표 및 제2 왜곡 픽셀좌표를 연결한 벡터가 이루는 각을 의미하며, 항상 양의 값을 가진다. The guided vehicle measuring device 300 obtains the first distorted pixel coordinates by replacing the coordinates of the entry point at the first time point t1 in the converted distorted pixel coordinates.

and second distortion pixel coordinates replacing the coordinates of the impact point at the second time point t2

Calculate the second inclination angle (θ _est ) using Here, the second inclination angle θ _est means an angle formed by a vector connecting the first and second distorted pixel coordinates with respect to the horizontal line of the ground in the 2D image coordinates, and always has a positive value.

The guided vehicle measuring device 300 calculates the second inclination angle θ _est using [Equation 9].

: 제1 왜곡 픽셀좌표의 x 좌표,

: 제1 왜곡 픽셀좌표의 y 좌표,

: 제2 왜곡 픽셀좌표의 x 좌표,

: 제2 왜곡 픽셀좌표의 y 좌표,

:

,

:

)(θ _est : second inclination angle,

: x coordinate of the first distortion pixel coordinate,

: y coordinate of the first distortion pixel coordinate,

: x coordinate of the second distortion pixel coordinate,

: y coordinate of the second distortion pixel coordinate,

:

,

:

)

The guided vehicle measuring device 300 generates impact information including a final approach angle and a final impact angle using the first inclination angle and the second inclination angle (S480, S482, and S490). The guided vehicle measuring device 300 uses an objective function to calculate the optimal final entry angle and final impact angle, and performs iterative calculations through the objective function.

The guided vehicle measuring device 300 is an objective function that minimizes the residual square of the first inclination angle (θ _m ) calculated from the impact image and the second inclination angle (θ _est ) estimated through the preset initial entry value and the initial impact angle. to calculate the final entry angle and final impact angle. The objective function can be defined in various ways, and the algorithm for calculating the optimal value is not necessarily limited thereto and can be modified in various forms.

The guided flight vehicle measuring device 300 updates the approach angle and impact angle when the output value of the objective function is greater than the tolerance (ε) set by the objective function. The guided vehicle measuring device 300 repeatedly calculates the entry angle and the impact angle until the output value of the objective function is less than the allowable error (ε).

The guided vehicle measuring device 300 calculates the output value of the objective function using [Equation 10]. Here, k is the number of cameras and w is the weight.

The guided vehicle measuring device 300 determines the final approach angle and the final impact angle of the objective function that satisfies the tolerance (ε) criterion.

In Figures 3 and 4, each step is described as sequentially executed, but is not necessarily limited thereto. In other words, since it will be applicable by changing and executing the steps described in FIGS. 3 and 4 or executing one or more steps in parallel, FIGS. 3 and 4 are not limited to a time-series order.

The method for measuring impact information of the guided flight vehicle according to the present embodiment described in FIGS. 3 and 4 may be implemented as an application (or program) and recorded on a recording medium readable by a terminal device (or computer). The application (or program) for implementing the method of measuring impact information of the guided flight vehicle according to this embodiment is recorded and the recording medium readable by the terminal device (or computer) stores all kinds of data that can be read by the computing system. It includes a recording device or medium of

5 is an exemplary view showing images of an impact at an entry point and a point of impact according to an embodiment of the present invention.

FIG. 5 shows two-dimensional impact images obtained from each of the plurality of cameras C1, C2, and C3 included in the guided vehicle measurement system 100.

In FIG. 5, the entry position of the guided vehicle at the entry time point t1 shown in the impact image is represented by P _t1 , and the impact position of the guided vehicle at the impact time point t2 shown in the impact image is indicated by P _t2 .

6 is an exemplary diagram showing an inclination angle at which a guided flight vehicle lands according to an embodiment of the present invention.

The first inclination angle calculated based on the image of the impact in the guided vehicle measuring device 300 is shown.

The guided vehicle measuring device 300 calculates a first inclination angle formed by a vector connecting the entry position (P _t1 ) of the guided vehicle and the impact position (P _t2 ) with respect to the horizontal line of the ground in the image of the impact.

Referring to FIG. 6 , the guided vehicle measuring device 300 indicates a first inclination angle for each of the impact images obtained from each of the plurality of cameras C1 , C2 , and C3 .

In FIG. 6 , the first inclination angle θ ₁ calculated from the impact image of the first camera C1, the first inclination angle θ ₂ calculated from the impact image of the second camera C2, and the third camera C3 It shows the first inclination angle (θ ₃ ) calculated from the impact image.

7 is a diagram for explaining a relationship between coordinate systems for measuring a guided vehicle according to an embodiment of the present invention.

Coordinate systems used in the guided vehicle measurement system 100 according to an embodiment of the present invention and relationships therebetween are shown.

The target coordinate system (X, Y, Z) is defined as the North-East-Down (NED) coordinate system with the center of the target as the origin and the X-axis as the true north direction, the Y-axis as the east, and the Z-axis as the ground.

The impact coordinate system (X _i , Y _i , Z _i ) is a coordinate system rotated by the entry and impact angles in the target coordinate system with the impact point as the origin.

The camera coordinate system (X _c , Y _c , Z _c ) is a coordinate system in which the center of the camera lens (focus) is the origin, and the Z-axis is the front optical axis direction, the X-axis is the right direction, and the Y-axis is the downward direction.

The pixel image coordinate system (X _p , Y _p ) is an acquired image coordinate system. It is a pixel unit coordinate system on a plane defined by the origin at the top left end point of the image, the right direction as the X axis, and the down direction as the Y axis. A three-dimensional point in space is projected. The distance from the camera origin is equal to the focal length.

The normalized image coordinate system (u, v) is an imaginary plane with a distance of 1 from the camera focal point, and the unit of the coordinate system is normalized to remove the influence of the camera's internal parameters. The origin of the normalized image coordinate system is the center of the plane and the point of intersection with the camera optical axis (Z _c ), and the right direction is defined as the u-axis and the downward direction as the v-axis.

The guided vehicle measuring device 300 according to the present embodiment calculates the first inclination angle and the second inclination angle through conversion between coordinate systems such as a target coordinate system, an impact coordinate system, a pixel image coordinate system, a normalized image coordinate system, and a camera coordinate system, thereby determining the final shape of the guided vehicle. The entry angle and the final impact angle are calculated to generate impact information.

The above description is only illustrative of the technical idea of the embodiment of the present invention, and those skilled in the art to which the embodiment of the present invention belongs can make various modifications and modifications within the scope not departing from the essential characteristics of the embodiment of the present invention. transformation will be possible. Therefore, the embodiments of the present invention are not intended to limit the technical idea of the embodiment of the present invention, but to explain, and the scope of the technical idea of the embodiment of the present invention is not limited by these examples. The protection scope of the embodiments of the present invention should be construed according to the claims below, and all technical ideas within the equivalent range should be construed as being included in the scope of the embodiments of the present invention.

100: guided flight instrument system
200: image capture device 300: guided air vehicle measuring device
310: initial coordinate measurement unit 320: impact image acquisition unit
330: pixel coordinate extraction unit 340: measurement processing unit

Claims (13)

A method for measuring impact information in a guided flight vehicle measuring device,
an initial coordinate measurement step of measuring the coordinates of a target and the coordinates of an image capture device installed at a preset distance and angle based on the center of the target;
When the guided vehicle lands on the ground, an image capture step of acquiring an image of the impact of the guided vehicle with respect to the location of the impact from the image capture device;
a pixel coordinate extraction step of extracting image pixel coordinates for the entry point and the point of impact of the guided vehicle based on the image of the impact; and
A first inclination angle is calculated based on the image pixel coordinates, a second inclination angle is calculated based on the distortion pixel coordinates calculated using a predetermined initial entry value and an initial impact angle, and the first inclination angle and the second inclination angle are calculated. A measurement processing step of generating impact information including a final approach angle and a final impact angle using
A method for measuring impact information of a guided flight vehicle, comprising: According to claim 1,
The pixel coordinate extraction step,
Extracting pixel coordinates of a first image at a first viewpoint and pixel coordinates of a second image at a second viewpoint within the image of the impact,
The first image pixel coordinates are coordinates extracted at the point of entry of the guided vehicle, and the second image pixel coordinates are coordinates extracted at the point of impact of the guided vehicle. According to claim 2,
In the measurement processing step,
a first inclination angle calculation step of converting a target coordinate system and calculating the first inclination angle using the first image pixel coordinates and the second image pixel coordinates;
Converting the impact coordinate system, calculating first spatial coordinates and second spatial coordinates based on the preset initial entry value and the initial impact angle, and converting the first spatial coordinates and the second spatial coordinates into normalized image coordinates a second inclination angle calculating step of calculating the second inclination angle by calculating first and second distortion pixel coordinates after converting to ?; and
An impact information measurement and processing step of generating the impact information including the final approach angle and the final impact angle by using an objective function based on the first inclination angle and the second inclination angle
A method for measuring impact information of a guided flight vehicle, comprising: According to claim 3,
In the first inclination angle calculation step,
The first inclination angle formed by a vector connecting the entry point of the pixel coordinates of the first image and the point of impact of the pixel coordinates of the second image with respect to the horizontal line of the ground in the impact image

(θ _m : 1st tilt angle, x _p1 : x coordinate of pixel coordinates of 1st image, y _p1 : y coordinate of pixel coordinates of 1st image, x _p2 : x coordinate of pixel coordinates of 2nd image, y _p2 : 2nd image y coordinate in pixel coordinates, y' _p1 : - y _p1 , y' _p2 : - y _p2 )
Calculated using , wherein the first inclination angle is always a positive value. According to claim 3,
The second inclination angle calculation step,
Estimating the first spatial coordinates and the second spatial coordinates obtained by converting the impact coordinate system into a target coordinate system using the initial entry value and the initial impact angle;
After converting the first spatial coordinates and the second spatial coordinates based on the normalized image coordinate system, the first distorted pixel coordinates and the coordinates of the second viewpoint to replace the coordinates of the first viewpoint through pixel image coordinate system conversion Calculate the second distortion pixel coordinates for replacement,
and calculating the second inclination angle using the first distorted pixel coordinates and the second distorted pixel coordinates. According to claim 5,
The second inclination angle calculation step,
The second inclination angle is determined based on the first distortion pixel coordinate and the second distortion pixel coordinate.

(θ _est : second inclination angle,

: x coordinate of the first distortion pixel coordinate,

: y coordinate of the first distortion pixel coordinate,

: x coordinate of the second distortion pixel coordinate,

: y coordinate of the second distortion pixel coordinate,

:

,

:

)
A method for measuring impact information of a guided flight vehicle, characterized in that for calculating using According to claim 3,
The impact information measurement processing step,
Wherein the impact information including the final approach angle and the final impact angle is generated using an objective function that minimizes the square of the residual of the first inclination angle and the second inclination angle. According to claim 7,
The impact information measurement processing step,
If the calculated value of the objective function is greater than or equal to the preset tolerance, an operation of updating the initial entry value and the initial impact angle to calculate a new second inclination angle is repeated, and the residuals of the first inclination angle and the new second inclination angle are repeated. The method of measuring impact information of a guided vehicle, characterized in that for calculating the final approach angle and the final impact angle that minimize the square. In the device for measuring the impact information of the guided flight vehicle,
an initial coordinate measurement unit for measuring coordinates of a target and coordinates of an image capture device installed at a preset distance and angle based on the center of the target;
When the guided vehicle lands on the ground, an impact image acquisition unit for acquiring an image of the impact of the guided vehicle with respect to the location of the impact from the image capture device;
a pixel coordinate extraction unit for extracting image pixel coordinates of the entry point and the point of impact of the guided vehicle based on the image of the impact; and
A first inclination angle is calculated based on the image pixel coordinates, a second inclination angle is calculated based on the distortion pixel coordinates calculated using a predetermined initial entry value and an initial impact angle, and the first inclination angle and the second inclination angle are calculated. Measurement processing unit for generating impact information including the final approach angle and the final impact angle using
A guided flight instrument comprising a. According to claim 9,
The pixel coordinate extraction unit,
Extracting pixel coordinates of a first image at a first viewpoint and pixel coordinates of a second image at a second viewpoint within the image of the impact,
The first image pixel coordinates are coordinates extracted at the point of entry of the guided vehicle, and the second image pixel coordinates are coordinates extracted at the point of impact of the guided vehicle. According to claim 10,
The measurement processing unit,
Converting a target coordinate system and calculating the first inclination angle using the pixel coordinates of the first image and the pixel coordinates of the second image;
Transforming the impact coordinate system, calculating first spatial coordinates and second spatial coordinates based on the preset initial entry value and the initial impact angle, and converting the first spatial coordinates and the second spatial coordinates into normalized image coordinates After converting to , the second tilt angle is calculated by calculating the first distortion pixel coordinate and the second distortion pixel coordinate,
and generating the impact information including the final approach angle and the final impact angle by using an objective function based on the first inclination angle and the second inclination angle. According to claim 11,
The measurement processing unit,
Calculate the first inclination angle formed by a vector connecting the entry point of the pixel coordinates of the first image and the point of impact of the pixel coordinates of the second image with respect to the horizontal line of the ground in the impact image, wherein the first inclination angle is always a positive value A guided flight instrument, characterized in that. According to claim 11,
The measurement processing unit,
Estimating the first spatial coordinates and the second spatial coordinates obtained by converting the impact coordinate system into a target coordinate system using the initial entry value and the initial impact angle;
After converting the first spatial coordinates and the second spatial coordinates based on the normalized image coordinate system, the first distorted pixel coordinates and the coordinates of the second viewpoint to replace the coordinates of the first viewpoint through pixel image coordinate system conversion Calculate the second distortion pixel coordinates for replacement,
and calculating the second inclination angle using the first distorted pixel coordinates and the second distorted pixel coordinates.

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