Timing system error correction method for interpreting miss distance change rate based on same-frame picture target

Abstract

The invention provides a timing system error correction method based on a target interpretation miss distance change rate of a same-frame picture, and the method employs a principle that the target picture distances of different lenses of the same device are consistent at the same time. Timing system error correction is carried out on different lenses of the same device by utilizing the distance change condition of two target pictures between different lenses of the same frame of picture for the first time, the device timing system error problem is converted into the miss distance change value difference problem between the different lenses, and finally the device timing system error problem is converted into the intersection point coordinate problem of a time distance analysis formula and a time axis; compared with traditional same target angle difference correction, the method is simple and clear in principle, convenient in implementation steps, higher in sensitivity and capable of being carried out along with task implementation, time system error judgment of all equipment is carried out for each task, additional shooting work is not needed, the time system condition of the equipment is mastered at any time, and time resources of personnel are effectively saved.

Description

Technical Field

[0001] The invention belongs to the technical field of exterior ballistic measurement data processing, and in particular relates to a time-synchronous error correction method based on the rate of change of target miss distance in the same frame. Background Art

[0002] The miss amount is a key indicator for evaluating the guidance accuracy of missile weapons. In current weapon tests, the miss amount data is mainly processed based on the measurement information of the photoelectric theodolite. This processing requires very high synchronization of the photoelectric theodolite equipment. The current photoelectric theodolite generally integrates multiple measurement sensors such as visible light high-speed photography, infrared, and video. When the timing of different photoelectric theodolites is consistent, there are deviations between different sensors of individual equipment. This deviation has a great impact on the accuracy of the miss amount processing and must be detected and corrected, otherwise it will affect the accuracy of the processing results. The current methods for detecting the synchronization of equipment mainly include high-frequency flash detection calibration method, characteristic event detection method, etc. The high-frequency flash detection calibration method designs different frequency differences between the flash and the light measuring device, and uses high-frequency shooting of the duration of the flash on and off, and compares it with the flash time system to determine the deviation of the measurement sensor time system. The advantage of this method is high measurement accuracy, but the disadvantage is that it must be carried out in advance, requires external equipment, and can only detect and calibrate visible light sensors; the characteristic event detection method is to observe the same sudden instantaneous characteristic event (such as explosion, etc.) by each sensor, and compare the corresponding time to determine the synchronization of time. The advantage of this method is that it can be carried out in each task without external equipment. The disadvantage is that since the shooting frequency of most devices is much lower than the time period corresponding to the instantaneous characteristic event, this method can only give a conclusion of synchronization or asynchrony, and cannot give a specific time deviation, and cannot accurately correct errors in data processing. At present, there is no effective treatment method in China for the problem of consistency detection of multi-sensor time systems of the same device under task conditions. Summary of the invention

[0003] In order to solve the above problems, the present invention provides a time-synchronous error correction method based on the change rate of the miss amount of the target interpretation in the same frame. The change trends of the miss amount of the visible light lens and the infrared lens are used to model the change trends of the two respectively, and the time-synchronous problem is converted into the intercept difference problem of the two equations, thereby achieving the purpose of time-synchronous error correction.

[0004] A time error correction method based on the change rate of target miss distance in the same frame includes the following steps:

[0005] Get the image distance R of the two targets in the visible light lens at two times t1 and t2 respectively 光1 , R 光2, and the image distance R between the two targets in the infrared lens installed on the same device as the visible light lens at two times t1 and t2 红1 , R 红2 ;

[0006] According to (t1, R 光1 ), (t2, R 光2 ) Get the analytical expression R of the time distance equation of the visible light lens 光 , and according to (t1, R 红1 ), (t2, R 红2 ) Get the analytical expression R of the time distance equation of the infrared lens 红 ;

[0007] Get the analytical expression of the time distance equation R 光 The coordinates of the intersection with the time axis are (t 光0 ,0), time distance equation analytical formula R 红 The coordinates of the intersection with the time axis are (t 红0 , 0);

[0008] t 红0 With t 光0 The time error Δt between the visible light lens and the infrared lens is obtained by subtraction, where if Δt≠0, the time error of the infrared lens is corrected according to Δt, and if Δt<0, it means that the infrared lens lags behind, and if Δt>0, it means that the infrared lens is ahead.

[0009] Furthermore, the screen distance R 光1 , R 光2 The calculation method is as follows:

[0010]

[0011] Among them, (x 光M1 ,y 光M1 ) is the miss distance of the first target in the visible light lens at time t1, (x 光T1 ,y 光T1 ) is the miss distance of the second target in the visible light lens at time t1, (x 光M2 ,y 光M2 ) is the miss distance of the first target in the visible light lens at time t2, (x 光T2 ,y 光T2 ) is the miss value of the second target in the visible light lens at time t2; w 光 and h 光 are the width and length of the pixel of the visible light lens respectively;

[0012] Screen distance R 红1 , R 红2 The calculation method is as follows:

[0013]

[0014] Among them, (x 红M1 ,y 红M1 ) is the miss distance of the first target in the infrared lens at time t1, (x 红T1 ,y 红T1 ) is the miss distance of the second target in the infrared lens at time t1, (x 红M2 ,y 红M2 ) is the miss distance of the first target in the infrared lens at time t2, (x 红T2 ,y 红T2 ) is the miss value of the second target in the infrared lens at time t2; w 红 and h 红 are the width and length of the pixel of the infrared lens respectively.

[0015] Furthermore, the analytical expression of the time distance equation R 光 for:

[0016]

[0017] The analytical formula of the time distance equation R 红 for:

[0018]

[0019] Here, t represents time.

[0020] Furthermore, t 光0 The calculation method is as follows:

[0021]

[0022] t 红0 The calculation method is as follows:

[0023]

[0024] Furthermore, the relative speed between the two targets in the same frame captured by the visible light lens and the infrared lens is greater than a set threshold.

[0025] Beneficial effects:

[0026] The present invention provides a time-synchronous error correction method based on the change rate of miss amount of target interpretation in the same frame. The method utilizes the principle that the distance of target images of different lenses of the same device is consistent at the same time, and proposes for the first time to use the change of the distance of two target images between different lenses of the same frame to perform time-synchronous error correction on different lenses of the same device, and converts the time-synchronous error problem of the device into the problem of the difference of the change value of miss amount between different lenses, and finally converts it into the problem of the intersection coordinates of the time distance analytical expression and the time axis. Compared with the traditional correction of the angle difference of the same target, the present invention has a simple and clear principle, convenient implementation steps, and higher sensitivity, and can be carried out along with the implementation of tasks. The time-synchronous error judgment of each device is performed for each task, and no additional shooting work is required. The time-synchronous situation of the device can be mastered at any time, and the time resources of personnel are effectively saved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A flow chart of a time error correction method based on the rate of change of target miss distance in the same frame provided by the present invention;

[0028] Figure 2 A schematic diagram of time error correction based on the rate of change of target miss distance in the same frame provided by the present invention. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0030] A time-coordinated error correction method based on the change rate of target miss amount in the same frame is proposed. Two targets are captured by each sensor (the two targets can be aerial targets, or one aerial target and one ground target, and there is a large speed difference between the two targets). The two targets in the image are interpreted, and the image distance between the two targets is obtained by combining the focal length, image resolution and pixel size, and a time series is formed. As time changes, the image distance between the two targets also changes. The time-coordinated error between the visible light lens and the infrared lens of the same device is detected and the deviation is calibrated by the change rate of the target image distance. The method is based on the fact that the target miss amount in the same device and at the same time is basically consistent. The change trend of the visible light lens and the infrared lens miss amount is used to model the change trends of the two respectively, and the time-coordinated problem is converted into the intercept difference problem of the two equations, so as to achieve the purpose of time-coordinated error correction and solve the current time-coordinated error problem of optical measurement in the shooting range.

[0031] Specifically, Figure 1 As shown, a time-series error correction method based on the rate of change of target miss distance in the same frame includes the following steps:

[0032] S1: Obtain the image distance R of two targets in the visible light lens at two times t1 and t2 respectively 光1 , R 光2 , and the image distance R between the two targets in the infrared lens installed on the same device as the visible light lens at two times t1 and t2 红1 , R 红2 ;

[0033] It should be noted that, assuming that the focal length of a device's visible light lens is f 光 , the pixel size is w 光 ×h 光 ; The focal length of the infrared lens is f 红 , the pixel size is w 红 ×h 红 In data processing, the image interpretation miss amount is based on the image screen coordinate system (the origin is in the upper left corner of the image, the x-axis is positive horizontally to the right, and the y-axis is positive vertically downward), and the image center point is x0, y0, representing the center of the device optical axis.

[0034] At time t1, the miss value of the first target of the visible light lens is x 光M1 ,y 光M1 , the second target miss value is x 光T1 ,y 光T1 ; The infrared lens's first target's miss value is x 红M1 ,y 红M1 , the second target’s miss value is x 光T1 ,y 光T1 According to the principle of photoelectric theodolite, the dimension of the off-target value is restored. At this time, the distances between the two target images in the visible light lens and the infrared lens are:

[0035]

[0036]

[0037] At time t2, the miss value of the first target of the visible light lens is x 光M2 ,y 光M2 , the second target’s miss value is x 光T2 ,y 光T2 ; The infrared lens's first target's miss value is x 红M2 ,y 红M2 , the second target’s miss value is x 光T2 ,y 光T2 , at this time, the distances between the visible light lens and the infrared lens are:

[0038]

[0039]

[0040] S2: According to (t1, R 光1 ), (t2, R 光2 ) Get the analytical expression R of the time distance equation of the visible light lens 光 , and according to (t1, R 红1 ), (t2, R 红2 ) Get the analytical expression R of the time distance equation of the infrared lens 红 ;

[0041] It should be noted that, since the same frame appears for a very short time, the motion of the first target and the second target can be regarded as uniform motion. The function of the distance between the two target images with respect to time is a quadratic equation, which is given by (t1, R 光1 ), (t2, R 光2 ) These two points can be used to calculate the analytical expression of the time distance equation of the visible light lens:

[0042]

[0043] Similarly, the analytical expression of the time distance equation of the infrared lens can be obtained as follows:

[0044]

[0045] S3: Get the analytical formula R of the time distance equation 光 The coordinates of the intersection with the time axis are (t 光0 ,0), time distance equation analytical formula R 红 The coordinates of the intersection with the time axis are (t 红0 , 0);

[0046] The coordinates of the intersection of the above analytical formula (5) and the time axis are (t 光0 , 0), then

[0047]

[0048] The coordinates of the intersection of the above analytical formula (6) and the time axis are (t 红0 , 0), then

[0049]

[0050] S4: 红0 With t 光0 The time deviation Δt between the visible light lens and the infrared lens is obtained by difference. If Δt≠0, the infrared lens time error is corrected according to Δt. If Δt<0, it means that the infrared lens lags behind, and if Δt>0, it means that the infrared lens is ahead.

[0051] It should be noted that since the distance between the device and the target is relatively far, generally reaching tens of kilometers to dozens of kilometers, the installation position deviation of the visible light lens and the infrared lens can be ignored at this time, and the time deviation between the visible light lens and the infrared lens is:

[0052] Δt=t 红0 -t 光0 (9)

[0053] If Δt<0, it means that the infrared lens is lagging; if Δt>0, it means that the infrared lens is ahead.

[0054] At this time, the timing error of the infrared lens can be corrected.

[0055] It can be seen that the present invention mainly utilizes the same device to shoot targets with the same distance angle when different lenses are used. At this time, the timing error can be reflected by the difference in the target miss amount of the same frame, thereby correcting the timing error of the infrared lens. When the relative speed of the two targets in the same frame is greater, the sensitivity of this method is higher; when the relative speed is smaller, the sensitivity of this method is lower. When the relative speed of the two targets is extremely small, or even remains relatively still, this method is no longer applicable. The operation process of the present invention is described as follows:

[0056] 001. Create a task, load the image, check the information, and use the characteristic event moments in the image to align the time system of the high frame rate visible light sensor to ensure the accuracy of the visible light lens timing.

[0057] 002. Perform target interpretation on the same frame of the visible light lens and infrared lens of each device, and generate the missed target value.

[0058] 003. Perform dimensional restoration on the interpreted miss distance, calculate the target distance at each moment of the same frame of different lenses, and obtain the time distance point.

[0059] 004. Calculate the time distance analytical formula of the miss distance of the visible light lens and the infrared lens using the time distance points. In the actual calculation process, since the shooting frequency of the visible light lens is high, the number of images in the same frame time period of the target is large, and the generated visible light lens time distance points are also more. At this time, the present invention can use linear fitting to minimize the impact of the interpretation error, thereby obtaining the visible light lens time distance analytical formula.

[0060] 005. As Figure 2 As shown in the figure, the time-distance analytical images of the visible light lens and the infrared lens are made in the same coordinate system. When R = 0, t 红0 With t 光0The difference is the time error between the infrared lens and the visible light lens. Theoretically, the analytical image slopes of the visible light lens and the infrared lens are exactly the same, but in the actual calculation process, due to system errors, interpretation errors and other reasons, there will be a very small difference between the two slopes. After calculation and comparison, the difference between the two slopes is about 1%. For t 红0 With t 光0 The impact of can be ignored.

[0061] 006. According to t 红0 With t 光0 The time error correction of the infrared lens is carried out based on the difference, the correct infrared lens same-frame image interpretation data is obtained, and subsequent external ballistic data processing is carried out.

[0062] In summary, a time error correction method based on the miss amount change rate of the target interpretation in the same frame is proposed. Its main technical feature is that the method uses the principle of consistent target image distance of different lenses of the same device at the same time to convert the device time error problem into the difference problem of miss amount change value between different lenses, and finally into the intersection coordinate problem of the time distance analytical expression and the time axis. The main contents include the dimensional recovery mode of the miss amount in the same frame, the solution of the time distance equation analytical expression, and the solution of the intersection coordinates. It is simple and clear, with convenient implementation steps and higher sensitivity. It can be carried out with the implementation of the task, and the time error of each device can be judged for each task without additional shooting. The time status of the equipment can be mastered at any time, which effectively saves personnel time resources.

[0063] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may certainly make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A time error correction method based on the change rate of target miss distance in the same frame, characterized in that: The following steps are involved: Get the image distance R of the two targets in the visible light lens at two times t1 and t2 respectively 光1 , R 光2 , and the image distance R between the two targets in the infrared lens installed on the same device as the visible light lens at two times t1 and t2 红1 , R 红2 ; According to (t1, R 光1 ), (t2, R 光2 ) Get the analytical expression R of the time distance equation of the visible light lens 光 , and according to (t1, R 红1 ), (t2, R 红2 ) Get the analytical expression R of the time distance equation of the infrared lens 红 ; Get the analytical expression of the time distance equation R 光 The coordinates of the intersection with the time axis are (t 光0 ,0), time distance equation analytical formula R 红 The coordinates of the intersection with the time axis are (t 红0 , 0); t 红0 With t 光0 The time error Δt between the visible light lens and the infrared lens is obtained by subtraction, where if Δt≠0, the time error of the infrared lens is corrected according to Δt, and if Δt<0, it means that the infrared lens lags behind, and if Δt>0, it means that the infrared lens is ahead.

2. A time error correction method based on the rate of change of target miss distance in the same frame as claimed in claim 1, characterized in that: Screen distance R 光1 , R 光2 The calculation method is as follows: Among them, (x 光M1 ,y 光M1 ) is the miss distance of the first target in the visible light lens at time t1, (x 光T1 ,y 光T1 ) is the miss distance of the second target in the visible light lens at time t1, (x 光M2 ,y 光M2 ) is the miss distance of the first target in the visible light lens at time t2, (x 光T2 ,y 光T2 ) is the miss value of the second target in the visible light lens at time t2; w 光 and h 光 are the width and length of the pixel of the visible light lens respectively; Screen distance R 红1 , R 红2 The calculation method is as follows: Among them, (x 红M1 ,y 红M1 ) is the miss distance of the first target in the infrared lens at time t1, (x 红T1 ,y 红T1 ) is the miss distance of the second target in the infrared lens at time t1, (x 红M2 ,y 红M2 ) is the miss distance of the first target in the infrared lens at time t2, (x 红T2 ,y 红T2 ) is the miss value of the second target in the infrared lens at time t2; w 红 and h 红 are the width and length of the pixel of the infrared lens respectively.

3. A time error correction method based on the rate of change of target miss distance in the same frame as claimed in claim 1, characterized in that: The analytical formula of the time distance equation R 光 for: The analytical formula of the time distance equation R 红 for: Here, t represents time.

4. The optical miss distance processing method based on trajectory and same-frame image constraints as claimed in claim 1, characterized in that: t 光0 The calculation method is as follows: t 红0 The calculation method is as follows:

5. The optical miss distance processing method based on trajectory and same-frame constraints according to any one of claims 1 to 4, characterized in that: The relative speed between two targets in the same frame captured by the visible light lens and the infrared lens is greater than a set threshold.

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