Photoelectric pod angle positioning method

Abstract

The invention discloses a photoelectric pod angle positioning method, and relates to the field of electrical digital data processing, and the method comprises the steps: deploying three aircrafts carrying photoelectric pods around a to-be-measured target; locking a to-be-measured target, and measuring an included angle between each photoelectric pod and the to-be-measured target; the photoelectric nacelles are distributed in pairs to obtain three combinations, any combination is matched with the target to be measured to form three points, and a circumcircle is determined respectively; calculating coordinates of three circumscribed circle centers and distances between the to-be-measured target and the three circumscribed circle centers according to the coordinates of the photoelectric nacelles and the included angles between the photoelectric nacelles and the to-be-measured target; and positioning the to-be-measured target. According to the method, the accurate position of the target to be measured is obtained through geometric angle operation and numerical arithmetic operation, the method is simple and easy to implement, complex and inaccurate distance measurement is avoided, and the method is suitable for being widely applied to complex environments.

Description

Technical Field

[0001] The invention relates to the field of electrical digital data processing, and in particular to a photoelectric pod angle positioning method. Background Art

[0002] The optoelectronic pod is usually composed of an optical imaging system, a stable platform, a data processing and transmission unit, and a shell. When the aircraft carrying the optoelectronic pod flies to the target area, the optical imaging system starts working and generates a clear image.

[0003] At present, optoelectronic pods play a key role in military reconnaissance, mapping, security monitoring and other fields. They can accurately observe and track targets. This advantage makes optoelectronic pods often used in the field of aircraft-based positioning.

[0004] However, conventional positioning algorithms not only need to track and lock the target, but also need to accurately measure the distance between the aircraft and the target. Therefore, it is urgent to develop an algorithm that can accurately locate the target by relying solely on the azimuth data when the optoelectronic pod tracks and locks the target. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides an optoelectronic pod angle positioning method which solves the problem of how to accurately locate a target to be measured by only relying on the azimuth angle data when the optoelectronic pod tracks and locks the target to be measured.

[0006] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0007] A method for angular positioning of an optoelectronic pod comprises the following steps:

[0008] S1. Deploy three aircrafts equipped with optoelectronic pods around the target to be measured;

[0009] S2. Lock the target to be measured by each optoelectronic pod and measure the angle between each optoelectronic pod and the target to be measured;

[0010] S3, assigning the optoelectronic pods in pairs to obtain three combinations, any combination and the target to be measured are matched to form three points, and each determines a circumscribed circle;

[0011] S4. Calculate the coordinates of the three circumscribed circle centers and the distances between the target to be measured and the three circumscribed circle centers through the coordinates of each optoelectronic pod and the angles between each optoelectronic pod and the target to be measured;

[0012] S5. Positioning the target to be measured according to the coordinates of the three circumscribed circle centers and the distances between the target to be measured and the three circumscribed circle centers.

[0013] Furthermore, in S1, the target to be measured is located in a triangle with three aircraft as vertices.

[0014] Further, the S2 comprises the following steps:

[0015] S21, any optoelectronic pod is recorded as A, the other two optoelectronic pods are recorded as B and C respectively, and the target to be measured is recorded as D;

[0016] S22, respectively detect and lock the optoelectronic pod B, optoelectronic pod C and the target D through the optoelectronic pod A, and record the azimuth angle corresponding to the optoelectronic pod A as ∠B A , ∠C A and ∠D A ;

[0017] S23. Calculate ∠BAD and ∠CAD by the following two formulas:

[0018] ,

[0019] ,

[0020] Among them, |∙| is the absolute value operator;

[0021] S24. Adopt the methods from S21 to S23 to measure ∠ABD, ∠CBD, ∠ACD and ∠BCD through the photoelectric pod B and the photoelectric pod C respectively.

[0022] Furthermore, in S4, the coordinates of any circumscribed circle center and its distance to the target to be measured are calculated as follows:

[0023] A1. Let the center of any circumscribed circle be O, the two optoelectronic pods on the circle be a and b, and the target to be measured be d.

[0024] A2, calculating ∠adb according to ∠abd and ∠bad measured by S2;

[0025] A3. Calculate ∠aOb based on ∠adb;

[0026] A4. According to the coordinates of the optoelectronic pod a, the coordinates of the optoelectronic pod b and ∠aOb, calculate the distance between the circumscribed circle center O and the target to be measured and the coordinates of the circumscribed circle center O.

[0027] Furthermore, the calculation formula of A2 is:

[0028] ,

[0029] Among them, π is the ratio of a circle to its circumference.

[0030] Furthermore, the calculation formula of A3 is:

[0031] ,

[0032] Among them, π is the ratio of a circle to its circumference.

[0033] Furthermore, A4 obtains the distance between the circumscribed circle center O and the target to be measured and the coordinates of the circumscribed circle center O by solving the following equations:

[0034] ,

[0035] Among them, x O is the horizontal coordinate of the circumcircle center O, y O is the ordinate of the circumcircle center O, x a is the horizontal coordinate of the optoelectronic pod a, y a is the ordinate of optoelectronic pod a, x b is the horizontal coordinate of the optoelectronic pod b, y b is the ordinate of the optoelectronic pod b, r is the distance between the circumscribed circle center O and the target to be measured, and cos(∙) is the cosine function.

[0036] Furthermore, the S5 locates the target to be measured by solving the following equation:

[0037] ,

[0038] Among them, x d is the horizontal coordinate of the target to be measured, y d is the ordinate of the target to be measured, x O1 is the abscissa of the first circumscribed circle center, y O1 is the ordinate of the first circumscribed circle center, x O2 is the abscissa of the second circumscribed circle center, y O2 is the ordinate of the second circumscribed circle center, x O3 is the abscissa of the third circumscribed circle center, y O3 is the ordinate of the third circumscribed circle center, r1 is the distance between the first circumscribed circle center and the target to be measured, r2 is the distance between the second circumscribed circle center and the target to be measured, and r3 is the distance between the third circumscribed circle center and the target to be measured.

[0039] The beneficial effects of the present invention are as follows: based on the characteristic that the optoelectronic pod can accurately observe and track the target to be measured, the present invention utilizes three aircraft equipped with optoelectronic pods, measures angle data, and obtains the precise position of the target to be measured through geometric angle calculations and numerical arithmetic calculations based on the coordinate position data of the three aircraft themselves. The method is simple and easy to implement, and also avoids complex and inaccurate distance measurement, and is suitable for wide application in complex environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A flow chart of a method for angular positioning of an optoelectronic pod provided by an embodiment of the present invention;

[0041] Figure 2A schematic diagram of the angles between each optoelectronic pod and the target to be measured according to an embodiment of the present invention;

[0042] Figure 3 Schematic diagram of calculating the coordinates of the circumscribed circle center and the distance between the target to be measured and the circumscribed circle center according to an embodiment of the present invention. DETAILED DESCRIPTION

[0043] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0044] like Figure 1 As shown, in one embodiment of the present invention, a method for angular positioning of an optoelectronic pod includes the following steps:

[0045] S1. Deploy three aircrafts equipped with optoelectronic pods around the target to be measured. The target to be measured is located in a triangle with the three aircrafts as vertices.

[0046] S2, locking the target to be measured by each optoelectronic pod and measuring the angle between each optoelectronic pod and the target to be measured, including the following steps:

[0047] S21. Any optoelectronic pod is denoted as A, the other two optoelectronic pods are denoted as B and C respectively, and the target to be measured is denoted as D.

[0048] S22, respectively detect and lock the optoelectronic pod B, optoelectronic pod C and the target D through the optoelectronic pod A, and record the azimuth angle corresponding to the optoelectronic pod A as ∠B A , ∠C A and ∠D A .

[0049] It is worth noting that in the prior art optoelectronic pod structure, its stable platform has two rotational degrees of freedom, one is the pitch angle and the other is the azimuth angle. The positioning described in the present invention is a two-dimensional positioning of longitude and latitude, that is, the calculation of the horizontal and vertical coordinates of the Cartesian coordinate system, without considering the altitude value. Therefore, the present invention only obtains the azimuth angle without paying attention to the pitch angle.

[0050] S23. Calculate ∠BAD and ∠CAD by the following two formulas:

[0051] ,

[0052] ,

[0053] Among them, |∙| is the absolute value operator.

[0054] S24. Using the methods of S21 to S23 above, ∠ABD, ∠CBD, ∠ACD and ∠BCD are measured by the photoelectric pod B and the photoelectric pod C respectively. These angles are shown in the figure below. Figure 2 shown.

[0055] S3. Allocate the optoelectronic pods in pairs to obtain three combinations. Any combination and the target to be measured are matched into three points, and each determines a circumscribed circle.

[0056] S4. Calculate the coordinates of three circumscribed circle centers and the distances between the target to be measured and the three circumscribed circle centers through the coordinates of each optoelectronic pod and the angles between each optoelectronic pod and the target to be measured.

[0057] In this embodiment, the coordinates of each optoelectronic pod can be obtained through the GPS or BeiDou system of the aircraft.

[0058] The coordinates of any circumscribed circle center and the distance between it and the target to be measured are calculated as follows:

[0059] A1. Let the center of any circumscribed circle be O, the two optoelectronic pods on the circle be a and b, and the target to be measured be d.

[0060] In order to facilitate those skilled in the art to understand the geometric model of the present invention, please refer to Figure 3 . Figure 3 The optoelectronic pods a and b in the figure are only relative numbers, not the absolute numbers of the three optoelectronic pods. However, for ease of understanding, Figure 2 The "photoelectric pod A" in Figure 3 The "photoelectric pod a" in Figure 2 The "photoelectric pod B" in Figure 3 The "photoelectric pod b" in Figure 2 The “target D to be measured” in Figure 3 In the “target d to be measured”, ∠BAD corresponds to ∠bad, and ∠ABD corresponds to ∠abd, which are known quantities measured in step S2.

[0061] A2. Calculate ∠adb based on ∠abd and ∠bad measured by S2:

[0062] ,

[0063] Among them, π is the ratio of the circumference of a circle. This formula is based on the triangle, that is, Figure 3 The sum of the three interior angles of Δabd is 180°.

[0064] A3. Calculate ∠aOb based on ∠adb:

[0065] ,

[0066] Wherein, π is the circumference of a circle. The principle of this formula is as follows: In the geometric model constructed by the present invention, Figure 3 It can be seen that since the target d is in the triangle formed by the three optoelectronic pods, ∠adb must be an obtuse angle. For an obtuse angle, in geometry, the central angle of the minor arc of its circumscribed circle has a numerical relationship with the obtuse angle, which is shown in this formula.

[0067] A4. According to the coordinates of the optoelectronic pod a, the coordinates of the optoelectronic pod b and ∠aOb, calculate the distance between the circumscribed circle center O and the target to be measured and the coordinates of the circumscribed circle center O by solving the following equations:

[0068] ,

[0069] Among them, x O is the horizontal coordinate of the circumcircle center O, y O is the ordinate of the circumcircle center O, x a is the horizontal coordinate of the optoelectronic pod a, y a is the ordinate of optoelectronic pod a, x b is the horizontal coordinate of the optoelectronic pod b, y b is the ordinate of the optoelectronic pod b, r is the distance between the circumscribed circle center O and the target to be measured, and cos(∙) is the cosine function.

[0070] For those skilled in the art, the first two of the above three equations are not difficult to understand. The principle of the third equation is as follows:

[0071] exist Figure 3 In the equation, let the intersection of line segment Od and line segment ab be e, then the length of line segment Ob is equal to the length of line segment Oa, and equal to r; at the same time, ∠aOe=∠bOe=1 / 2×∠aOb. Then the length of line segment Oe is equal to r×cos(∠aOe), and equal to r×cos(∠aOe), that is, equal to r×cos(1 / 2×∠aOe). According to the Pythagorean theorem, the length of line segment ae is equal to r 2 -r 2 ×cos(1 / 2×∠aOe), and further deduction can give the third equation of the above three equations.

[0072] This embodiment uses the same method, that is, according to Figure 2 From ∠CAD, ∠CBD, ∠ACD and ∠BCD, calculate the distances between the other two circumscribed circle centers and the target to be measured and the coordinates of the two circumscribed circle centers.

[0073] S5. According to the coordinates of the three circumscribed circle centers and the distances between the target to be measured and the three circumscribed circle centers, locate the target to be measured by solving the following equations:

[0074] ,

[0075] Among them, x d is the horizontal coordinate of the target to be measured, y d is the ordinate of the target to be measured, x O1 is the abscissa of the first circumscribed circle center, y O1 is the ordinate of the first circumscribed circle center, x O2 is the abscissa of the second circumscribed circle center, y O2 is the ordinate of the second circumscribed circle center, x O3 is the abscissa of the third circumscribed circle center, y O3 is the ordinate of the third circumscribed circle center, r1 is the distance between the first circumscribed circle center and the target to be measured, r2 is the distance between the second circumscribed circle center and the target to be measured, and r3 is the distance between the third circumscribed circle center and the target to be measured.

[0076] The above equation can directly deduce x d and d The analytical solution can also be numerically solved by numerical calculation methods in the computer field, which is not difficult for those skilled in the art, so this embodiment will not be repeated.

[0077] In summary, the present invention is based on the characteristics of the optoelectronic pod that can accurately observe and track the target to be measured. It uses three aircraft equipped with optoelectronic pods to measure angle data. Based on the coordinate position data of the three aircraft themselves, after geometric angle calculations and numerical arithmetic operations, the precise position of the target to be measured is obtained. The method is simple and easy, and also avoids complex and inaccurate distance measurement. It is suitable for wide application in complex environments.

[0078] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for angular positioning of an optoelectronic pod, characterized in that: The following steps are involved: S1. Deploy three aircrafts equipped with optoelectronic pods around the target to be measured; S2. Lock the target to be measured by each optoelectronic pod and measure the angle between each optoelectronic pod and the target to be measured; S3, assigning the optoelectronic pods in pairs to obtain three combinations, any combination and the target to be measured are matched to form three points, and each determines a circumscribed circle; S4. Calculate the coordinates of the three circumscribed circle centers and the distances between the target to be measured and the three circumscribed circle centers through the coordinates of each optoelectronic pod and the angles between each optoelectronic pod and the target to be measured; S5. Positioning the target to be measured according to the coordinates of the three circumscribed circle centers and the distances between the target to be measured and the three circumscribed circle centers.

2. The optoelectronic pod angle positioning method according to claim 1, characterized in that: In S1, the target to be measured is located in a triangle with three aircraft as vertices.

3. The optoelectronic pod angle positioning method according to claim 1, characterized in that: The S2 comprises the following steps: S21, any optoelectronic pod is recorded as A, the other two optoelectronic pods are recorded as B and C respectively, and the target to be measured is recorded as D; S22, respectively detect and lock the optoelectronic pod B, optoelectronic pod C and the target D through the optoelectronic pod A, and record the azimuth angle corresponding to the optoelectronic pod A as ∠B A , ∠C A and ∠D A ; S23. Calculate ∠BAD and ∠CAD by the following two formulas: ， ， Among them, |∙| is the absolute value operator; S24. Adopt the methods from S21 to S23 to measure ∠ABD, ∠CBD, ∠ACD and ∠BCD through the photoelectric pod B and the photoelectric pod C respectively.

4. The optoelectronic pod angle positioning method according to claim 1, characterized in that: In S4, the coordinates of any circumscribed circle center and the distance between the circumscribed circle center and the target to be measured are calculated as follows: A1. Let the center of any circumscribed circle be O, the two optoelectronic pods on the circle be a and b, and the target to be measured be d. A2, calculating ∠adb according to ∠abd and ∠bad measured by S2; A3. Calculate ∠aOb based on ∠adb; A4. According to the coordinates of the optoelectronic pod a, the coordinates of the optoelectronic pod b and ∠aOb, calculate the distance between the circumscribed circle center O and the target to be measured and the coordinates of the circumscribed circle center O.

5. The optoelectronic pod angle positioning method according to claim 4, characterized in that: The calculation formula of A2 is: ， Among them, π is the ratio of a circle to its circumference.

6. The optoelectronic pod angle positioning method according to claim 4, characterized in that: The calculation formula of A3 is: ， Among them, π is the ratio of a circle to its circumference.

7. The optoelectronic pod angle positioning method according to claim 4, characterized in that: A4 obtains the distance between the circumscribed circle center O and the target to be measured and the coordinates of the circumscribed circle center O by solving the following equations: ， Among them, x O is the horizontal coordinate of the circumcircle center O, y O is the ordinate of the circumcircle center O, x a is the horizontal coordinate of the optoelectronic pod a, y a is the ordinate of optoelectronic pod a, x b is the horizontal coordinate of the optoelectronic pod b, y b is the ordinate of the optoelectronic pod b, r is the distance between the circumscribed circle center O and the target to be measured, and cos(∙) is the cosine function.

8. The optoelectronic pod angle positioning method according to claim 1, characterized in that: The S5 locates the target to be measured by solving the following equation: ， Among them, x d is the horizontal coordinate of the target to be measured, y d is the vertical coordinate of the target to be measured, x O1 is the abscissa of the first circumscribed circle center, y O1 is the ordinate of the first circumscribed circle center, x O2 is the abscissa of the second circumscribed circle center, y O2 is the ordinate of the second circumscribed circle center, x O3 is the abscissa of the third circumscribed circle center, y O3 is the ordinate of the third circumscribed circle center, r1 is the distance between the first circumscribed circle center and the target to be measured, r2 is the distance between the second circumscribed circle center and the target to be measured, and r3 is the distance between the third circumscribed circle center and the target to be measured.

Images