An optical aiming inverse operation method and device

Abstract

The present invention discloses an optical aiming inverse operation method and device. The method includes: obtaining the non-levelness of the inertial measurement unit (IMU), the non-parallelism between the aiming prism ridge line and the IMU coordinate system, and obtaining the collimation elevation angle between the ground fixed-aiming IMU aiming optical tube and the aiming prism, and the azimuth angle between the ground fixed-aiming IMU aiming optical tube and the aiming prism after the rocket is erected; calculating the transformation matrix from the IMU coordinate system to the geodetic coordinate system; calculating the autocollimation optical tube vector and the ridge vector of the aiming prism in the geodetic coordinate system; at the collimation moment, calculating the final collimation azimuth angle according to the autocollimation optical tube vector and the ridge vector of the aiming prism in the geodetic coordinate system.

Description

Technical Field

[0001] The present invention relates to the field of optics, and particularly to an optical aiming inverse operation method and device. Background Art

[0002] The existing rocket aiming method is to use a north finder and a theodolite to perform optical aiming on site. The north finder is used to find the accurate north direction, and then the theodolite is used to aim at the inertial measurement unit (IMU) prism and align with the north finder to determine the collimation azimuth angle of the IMU. Combining the output of the IMU accelerometer, the accurate attitude of the IMU is calculated to achieve the initial alignment function of the rocket.

[0003] When using the existing aiming method on site, due to the high cost of the north finder and theodolite equipment and the high cost of their appearance, and the need to coordinate professional aiming personnel for aiming before the test, the process is complicated and the time flexibility is poor. Summary of the Invention

[0004] The present invention provides an optical aiming inverse operation method, including:

[0005] Obtaining the non-levelness of the IMU, the non-parallelism between the prism ridge line of the aiming prism and the IMU coordinate system, and obtaining the collimation elevation angle and azimuth angle between the ground fixed-aiming IMU aiming optical tube and the aiming prism after the rocket is erected;

[0006] Calculating the transformation matrix from the IMU coordinate system to the geodetic coordinate system;

[0007] Calculating the autocollimation optical tube vector and the ridge vector of the aiming prism in the geodetic coordinate system;

[0008] At the collimation moment, calculating the final collimation azimuth angle according to the autocollimation optical tube vector and the ridge vector of the aiming prism in the geodetic coordinate system.

[0009] For the optical aiming inverse operation method as described above, the unit vectors of the IMU coordinate axes in the geodetic coordinate system are expressed as Let The axis at O s X s Y s The projection O s Z m Of the plane and O s X s The included angle is α0, The axis at O s X s Y s The projection O s Y m And O s X s The included angle is α1;

[0010] Δψ0A , is the non-levelness of the inertial measurement unit;

[0011] g = w0 cos(α0), i = -w0 sin(α0), d = w1 cos(α1), f = -w1 sin(α1), where w0 is the length of the projection of O s Z m ; and w1 is the length of the projection of O s Y m ;

[0012] For an optical aiming inverse operation method as described above, assume and are the unit vectors of the geodetic coordinate system, then there is

[0013] Then obtain the transformation matrix from O M X M Y M Z M to O s X s Y s Z s :

[0014] For an optical aiming inverse operation method as described above, the autocollimator vector in the geodetic coordinate system is:

[0015] O s C = [x y z] = [cos(A ms ) cos(θ ms ) sin(θ ms ) sin(A ms ) cos(θ ms )] T , where θ ms is the collimation elevation angle between the ground fixed-aiming inertial measurement unit aiming collimator and the aiming prism after the rocket is erected, and A ms is the azimuth angle between the ground fixed-aiming inertial measurement unit aiming collimator and the aiming prism, that is, the aiming collimation azimuth angle.

[0016] For an optical aiming inverse operation method as described above, the ridge vector of the aiming prism in the inertial measurement unit coordinate system is: α, β are the non-parallelism between the prism line of the aiming prism and the planes of the OX M Z M , OY M Z M coordinate systems of the inertial measurement unit;

[0017] Let Then the ridge vector in the inertial navigation system coordinate system is expressed as According to the transformation matrix and the ridge vector in the inertial navigation system coordinate system calculate the ridge vector in the geodetic coordinate system

[0018] An optical aiming inverse operation method as described above, wherein, at the collimation moment, the optical path satisfies: That is:

[0019]

[0020] Solving the formula gives the final collimation azimuth as

[0021] The present invention also provides an optical aiming inverse operation device, including: the device executes the optical aiming inverse operation method described in any one of the above.

[0022] The beneficial effects achieved by the present invention are as follows:

[0023] 1. Without the need for optical aiming equipment and personnel costs, the cost is low;

[0024] 2. The process of reserving aiming personnel and equipment is omitted, and the optical aiming collimation azimuth can be calculated at any time, with simple operation and strong flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for description in the embodiments or the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings.

[0026] Figure 1 is a flowchart of an optical aiming inverse operation method provided in Embodiment 1 of the present invention;

[0027] Figure 2 is a schematic diagram of an inertial navigation system;

[0028] Figure 3 is a schematic diagram of the positional relationship between the inertial navigation system coordinate system and the geodetic coordinate system;

[0029] Figure 4 is a schematic diagram of the positional relationship between the aiming optical tube and the aiming prism. DETAILED DESCRIPTION OF THE INVENTION

[0030] The following clearly and completely describes the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0031] Embodiment 1

[0032] Embodiment 1 of the present invention provides an optical aiming inverse operation method, which is applied to an optical aiming inverse operation device, as Figure 1 shown, and includes:

[0033] Step 110: Obtain the non-levelness of the inertial measurement unit (IMU), the non-parallelism between the aiming prism edge line and the IMU coordinate system, and obtain the collimation elevation angle between the ground fixed-aiming IMU aiming optical tube and the aiming prism, and the azimuth angle between the ground fixed-aiming IMU aiming optical tube and the aiming prism after the rocket is erected.

[0034] Specifically, obtain the IMU parameters as Figure 2 shown, including obtaining and defining Δψ 0A , as the non-levelness of the IMU, α and β as the non-parallelism between the aiming prism edge line and the OX M Z M , OY M Z M coordinate system planes, θ ms is the collimation elevation angle between the ground fixed-aiming IMU aiming optical tube and the aiming prism after the rocket is erected, and A ms is the azimuth angle between the ground fixed-aiming IMU aiming optical tube and the aiming prism, that is, the aiming collimation azimuth angle.

[0035] Step 120: Calculate the transformation matrix from the IMU coordinate system to the geodetic coordinate system;

[0036] The unit vectors of the IMU coordinate axes in the geodetic coordinate system are expressed as as Figure 3 shown. Let the axis projection O s X s Y s in the O s Z m plane and the angle between O s X s be α0, the axis projection O s X s Y s plane and the angle between O s Y m and O s X s be α1;

[0037] where h = sin(Δψ 0A ) Calculate the length of the projection O s Z m ; The length of the projection O s Y m ; and calculate to obtain g = w0cos(α0), i = -w0sin(α0), d = w1 cos(α1), f = -w1sin(α1);

[0038] According to the characteristics of the orthogonal coordinate system, it can be obtained that:

[0039]

[0040] Thus, a, b, c, d, e, f, g, h, i are all expressed as functions of the unknowns α0 and α1;

[0041] From it can be obtained that dg + eh + fi = 0, that is

[0042] w0w1 cos(α0)cos(α1) + w0w1 sin(α0)sin(α1)

[0043] = w0w1 cos(α0 - α1)

[0044] = -eh

[0045] Let μ = α1 - α0, then Therefore Thus, a, b, c, d, e, f, g, h, i can all be expressed as functions of the unknown α1.

[0046] Let and be the unit vectors of the geodetic coordinate system, then there is

[0047]

[0048] Furthermore, it can be obtained that

[0049]

[0050] Obtain the transformation matrix from O M X M Y M Z M to O s X s Y s Z s :

[0051] That is, the transformation matrix All elements in are functions of the unknown quantity α1.

[0052] Step 130: Calculate the autocollimator vector and the ridge vector of the aiming prism in the geodetic coordinate system;

[0053] As Figure 4 shown, at the collimation moment, the autocollimator vector is perpendicular to the ridge vector of the aiming prism, realizing the transmission of the optical path.

[0054] Among them, the autocollimator vector in the geodetic coordinate system is:

[0055] O s C = [x y z] = [cos(A ms )cos(θ ms )sin(θ ms )sin(A ms )cos(θ ms )] T

[0056] The ridge vector of the aiming prism in the inertial measurement unit coordinate system is:

[0057] Let Then the ridge vector in the inertial measurement unit coordinate system is expressed as According to the transformation matrix and the ridge vector in the inertial measurement unit coordinate system, calculate the ridge vector

[0058] Step 140: At the collimation moment, calculate the final collimation azimuth angle according to the autocollimator vector and the ridge vector of the aiming prism in the geodetic coordinate system;

[0059] Since at the collimation moment, the optical path satisfies: That is:

[0060]

[0061] Solve the above equation. In this equation, a, b, c, d, f, g, i are functions of the unknown quantity α1, and h, e, k, j, w0, w1 can all be calculated from the input values:

[0062] xw0cos(α0) - zw0sin(α0) - ekzw0cos(α0) - ekxw0sin(α0) + jxw1cos(α1) - jzw1sin(α1)

[0063] +kzw1hcos(α1)+kxw1hsin(α1)+kyw0w1(cos(α1)sin(α0)-cos(α0)sin(α1))=-hy - ejy

[0064] Simplify the known quantities in the formula. Let Then transform the above formula into:

[0065] Continue to simplify the known quantities. Let Then the above is transformed into pcosα1 + qsinα1 = l. Continue to simplify. Let Solve the formula to obtain the final collimation azimuth angle as

[0066] The specific embodiments described above further elaborate on the object, technical solution, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made on the basis of the technical solution of the present invention shall be included within the protection scope of the present invention.

Claims

1. An optical aiming inverse operation method, characterized in that, Comprising: Obtaining the non-levelness of the inertial measurement unit, the non-parallelism between the aiming prism ridge line and the inertial measurement unit coordinate system, and obtaining the collimation elevation angle between the ground fixed-aiming inertial measurement unit aiming optical tube and the aiming prism, and the azimuth angle between the ground fixed-aiming inertial measurement unit aiming optical tube and the aiming prism after the rocket is erected; Calculating the transformation matrix from the inertial measurement unit coordinate system to the geodetic coordinate system; Calculating the autocollimation light tube vector and the ridge vector of the aiming prism in the geodetic coordinate system; At the collimation moment, calculating the final collimation azimuth angle according to the autocollimation light tube vector and the ridge vector of the aiming prism in the geodetic coordinate system; Vector of autocollimator under geodetic coordinate system It is as follows: O s C = [x y z] = [cos(A ms ) cos(θ ms ) sin(θ ms ) sin(A ms ) cos(θ ms )] T , θ ms is the collimation elevation angle between the ground fixed aiming inertial assembly aiming optical tube and the aiming prism after the rocket is erected, and A ms is the azimuth angle between the ground fixed aiming inertial assembly aiming optical tube and the aiming prism, that is, the aiming collimation azimuth angle; The ridge vector of the aiming prism in the INS coordinate system is as follows: α and β are the non-parallelism of the prism line of the aiming prism with the OX M Z M and OY M Z M coordinate system planes; Let Then the ridge vector in the inertial navigation system coordinate system is expressed as According to the transformation matrix and the ridge vector in the inertial navigation system coordinate system calculate the ridge vector in the geodetic coordinate system At the collimation moment, the optical path satisfies: That is: The solution formula yields the final collimation azimuth as 2. The optical aiming inverse operation method according to claim 1, characterized in that, The unit vectors of the INS coordinate axes are represented in the geodetic coordinate system as Let The axis at O s X s Y s The projection of the plane is O s Z m The angle between and O s X s is α0, The axis at O s X s Y s The projection of the plane is O s Y m The angle between and O s X s is α1; Δψ 0A 、 is the non-levelness of the inertial measurement unit; g = w0cos(α0), i = -w0sin(α0), d = w1cos(α1), f = -w1sin(α1), where w0 is the length of the projection O s Z m of and w1 is the length of the projection O s Y m of 3. The optical aiming inverse operation method according to claim 2, characterized in that Let and be the unit vectors of the geodetic coordinate system, then we have Then obtain the transformation matrix from O M X M Y M Z M to O s X s Y s Z s :

4. An optical aiming inverse operation device, characterized in that, Comprising: The device executes the optical aiming inverse operation method according to any one of claims 1-3.

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