Non-orthogonal analysis and correction method and system for two-dimensional turntable of laser terminal

Abstract

The application provides a laser terminal two-dimensional rotary table non-orthogonal analysis and correction method and system, comprising the following steps: step 1, establishing a reference coordinate system for a typical two-dimensional rotary table mechanism, and describing the rotation mode of the two-dimensional rotary table; step 2, establishing a model of driving the laser terminal optical axis rotation of the two-dimensional rotary table without non-orthogonal error; step 3, considering the influence of the non-orthogonal error on the laser terminal optical axis pointing, and establishing a non-orthogonal optical axis pointing transfer model; and step 4, establishing a calibration method according to the non-orthogonal optical axis pointing error model, and realizing the non-linear correction under a large range of rotation angles. The application can adapt to the correction under a large range of rotation, fundamentally solves the influence of non-orthogonality compared with the traditional linear fitting method, and has higher implementation precision.

Description

Technical Field

[0001] This invention relates to the field of satellite overall design and attitude control technology, specifically to a method and system for non-orthogonal analysis and correction of a two-dimensional turntable for a laser terminal. Background Technology

[0002] Optical axis pointing accuracy is a core performance indicator for laser terminals. Because the communication beam angle of laser terminals is very small, typically around 10°... -5 To ensure precise laser pointing to the communication target and establishing communication, accurate measurement of the laser terminal's optical axis in inertial space is required, often at the radian level. However, due to factors such as installation errors, emission vibrations, and on-orbit stress release, the rotating mechanism's axis installation exhibits non-orthogonal characteristics. Calculations based on the actual rotation angle of the 2D turntable cannot accurately reflect the laser terminal's pointing in inertial space, and the larger the rotation angle, the greater the resulting error in optical axis pointing measurement. Therefore, to improve the optical axis pointing accuracy of the laser terminal, it is necessary to conduct research on non-orthogonal analysis and correction methods for the 2D turntable.

[0003] Based on literature review, the paper "Research on Error Separation in Laser Inter-Satellite Link Terminal Pointing Error Calibration" (Journal of Astronautics, Vol. 40, No. 1, 2019) proposes a spacecraft attitude measurement error separation method based on multi-link measurements. This method utilizes the characteristic of a single spacecraft simultaneously establishing multiple links within a navigation constellation to acquire optical axis pointing error measurement data in different directions. By simultaneously estimating the spacecraft attitude measurement error and the optical axis pointing error parameters, the separation of these two-dimensional turntable errors is achieved. This paper primarily analyzes the impact of satellite platform attitude errors on the laser terminal's optical axis pointing, without addressing the non-orthogonal processing of the two-dimensional turntable.

[0004] The paper "Laser Communication Line-of-Sight Pointing Technology Based on Kalman Filtering" (Wireless Optical Communication, No. 9, 2018) proposes a method using a terrestrial fixed-point laser communication system as a background. It obtains the initial pointing angle through a coordinate transformation matrix, analyzes the factors affecting the accuracy of the line-of-sight pointing angle, and introduces Kalman filtering technology into the line-of-sight pointing system to complete system modeling. This paper treats optical communication line-of-sight pointing as a comprehensive system error and does not address the non-orthogonality of the two-dimensional turntable.

[0005] The paper "Method for Measuring the Accuracy of the Shaft System of a Coarse Pointing Mechanism in Laser Communication" (Aerospace Science and Technology Corporation Assembly Process Technology Center Exchange Column, Issue 1, 2020) introduces the technological challenges of measuring the tilt angle rotation error and perpendicularity of the shaft system at the arcsecond level. It describes the measurement principle, configuration method, and data processing procedure for measuring the accuracy of the shaft system using test examples. This paper focuses on the assembly process guarantee method for high-precision perpendicularity of the two-dimensional turntable, but does not cover the analysis and identification correction of the non-orthogonality of the two-dimensional turntable.

[0006] The paper "The Influence of Errors in a Rotating Biprism System on Pointing Accuracy in Laser Communication" (Optics & Precision Engineering, Vol. 6, 2021) analyzes the error sources in a rotating biprism system. Based on these sources, a beam pointing model is established using the ray vector propagation method. The partial derivatives of the beam pointing deviation with respect to the system error are then calculated based on this model. Within the pointing region, the impact of each error on pointing accuracy is analyzed according to the measurement accuracy of the various errors. This paper focuses on the influence of the rotating biprism on the optical axis pointing of the laser terminal and does not address the non-orthogonal problem of the two-dimensional turntable.

[0007] The thesis "Research on the Impact of Pointing Accuracy on the Performance of Inter-Satellite Laser Communication Terminals" (Master's Thesis, University of Chinese Academy of Sciences, 2021) investigated the impact of pointing error on the acquisition process during optical communication link establishment. Using a star sensor to obtain satellite attitude, an error model for the relay optical path branch was established, and the relationship between pointing error and two-axis rotation angles was analyzed. The impact of pointing error on acquisition probability and average acquisition time was also studied. This thesis similarly equates the optical axis pointing error of the laser terminal to the systematic deviation of the star sensor / satellite platform, without addressing the non-orthogonality problem of the two-dimensional turntable.

[0008] In summary, the non-orthogonal analysis and correction method for a two-dimensional turntable of a laser terminal proposed in this invention can adapt to correction under a wide range of rotations. Compared with the traditional linear fitting method, it fundamentally solves the influence of non-orthogonality and achieves higher implementation accuracy. Summary of the Invention

[0009] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method and system for non-orthogonal analysis and correction of a two-dimensional turntable for laser terminals.

[0010] The non-orthogonal analysis and correction method for a two-dimensional turntable of a laser terminal provided by the present invention includes:

[0011] Step S1: Establish a reference coordinate system for the two-dimensional turntable of the laser terminal and describe the rotation mode of the two-dimensional turntable of the laser terminal;

[0012] Step S2: Establish an optical axis pointing transfer model without non-orthogonal errors using the geometric transfer method;

[0013] Step S3: Add a non-orthogonal error transfer matrix to the optical axis pointing transfer model to establish an optical axis pointing transfer model containing non-orthogonal errors;

[0014] Step S4: Drive the two-dimensional turntable to point at different angles, establish equivalent equations on track using geometric calibration points, solve for the equivalent non-orthogonal deviation angle parameters, and substitute them into the optical axis pointing transmission model containing non-orthogonal errors, thereby eliminating the influence of non-orthogonality on optical axis pointing errors.

[0015] Preferably, step S1 includes:

[0016] First, define the pitch axis reference coordinate system, with the origin O. f Located at the center of the pitch axis, +Z f The axis is perpendicular to the turntable mounting surface and parallel to the direction of the laser terminal's optical axis; +Y f The axis is parallel to the pitch axis; X f axis and Y f Axis and Z f The axes form a right-handed rectangular coordinate system; according to the definition of the pitch axis reference coordinate system, the pitch mechanism revolves around the Y-axis. f The shaft rotates;

[0017] Then define the azimuth axis reference coordinate system, with the origin O. c Located at the center of the mounting area between the azimuth axis and the mounting surface, +X c The axis is parallel to the azimuth axis; when the azimuth axis is at zero, +Y c The axis is parallel to the pitch axis; X c axis and Y c Axis and Z c The axes form a right-handed rectangular coordinate system; according to the definition of the azimuth axis reference coordinate system, the azimuth mechanism revolves around the X-axis. c The shaft rotates;

[0018] Finally, define a two-dimensional rotary table reference coordinate system, with the origin O. b Located at the lower right corner of the mounting surface; when the azimuth axis is at zero, the X-axis of the two-dimensional turntable reference coordinate system... b Axis, Y b Axis, Z b X-axis and azimuth axis reference coordinate system c Axis, Y c Axis, Z c The axes are parallel.

[0019] Preferably, step S2 includes:

[0020] First, we analyze the influence of the pitch axis on the optical axis pointing of the laser terminal. The optical axis vector of the laser terminal is projected onto the azimuth axis reference coordinate system, and the expression is as follows:

[0021]

[0022] Then, considering the effect of azimuth axis rotation on the optical axis pointing of the laser terminal, the optical axis vector of the optical terminal is projected onto the two-dimensional turntable axis reference coordinate system, and the expression is as follows:

[0023]

[0024] Combining the two equations, we get:

[0025]

[0026] In the formula, This is the projection of the laser terminal optical axis vector onto the pitch axis reference coordinate system; β is the projection of the laser terminal optical axis vector onto the azimuth axis reference coordinate system; β is the pitch axis rotation angle. α is the projection of the laser terminal optical axis vector onto the two-dimensional turntable axis reference coordinate system; α is the azimuth axis rotation angle.

[0027] Preferably, step S3 includes:

[0028] The expression for the optical axis pointing transfer model containing non-orthogonal errors is:

[0029]

[0030] In the formula, R f The pitch axis non-orthogonal transfer matrix is ​​expressed as follows:

[0031]

[0032] In the formula, X f The pitch axis is the non-orthogonal rotation error relative to the X-axis, Y f Z represents the non-orthogonal rotation error of the pitch axis relative to the Y-axis. f X represents the non-orthogonal rotation error of the pitch axis relative to the Z-axis. f Y f Z f These are the three equivalent non-orthogonal deviation angle parameters of the pitch axis;

[0033] R c The azimuth axis non-orthogonal transfer matrix is ​​expressed as follows:

[0034]

[0035] In the formula, X c The azimuth axis is the non-orthogonal rotation error relative to the X-axis, Y c Z represents the non-orthogonal rotation error of the azimuth axis relative to the Y-axis. c The non-orthogonal rotation error of the azimuth axis relative to the Z-axis; X c Y c Zc These are the three equivalent non-orthogonal deviation angle parameters of the azimuth axis.

[0036] Preferably, step S4 includes:

[0037] The optical axis pointing transfer model containing non-orthogonal errors is simplified as follows:

[0038]

[0039] In the formula, X f Z f For the simplified pitch axis equivalent non-orthogonal deviation angle parameter, Y c Z c The simplified azimuth axis is equivalent to the non-orthogonal deviation angle parameter;

[0040] N x (α) is the azimuth axis transfer matrix, expressed as:

[0041]

[0042] N y (β) is the pitch axis transfer matrix, expressed as:

[0043]

[0044] Solve for the simplified equivalent non-orthogonal deviation angle parameter and substitute it into the optical axis pointing transmission model containing non-orthogonal error to eliminate the influence of non-orthogonality on optical axis pointing error.

[0045] The non-orthogonal analysis and correction system for a two-dimensional turntable of a laser terminal provided by the present invention includes:

[0046] Module M1: Establishes the reference coordinate system for the two-dimensional turntable of the laser terminal and describes the rotation mode of the two-dimensional turntable of the laser terminal;

[0047] Module M2: Establishes an optical axis pointing transfer model without non-orthogonal errors using the geometric transfer method;

[0048] Module M3: Add a non-orthogonal error transfer matrix to the optical axis pointing transfer model to establish an optical axis pointing transfer model containing non-orthogonal errors;

[0049] Module M4: Drives the two-dimensional turntable to point at different angles. On-orbit, it uses geometric calibration points to establish equivalent equations, solves for equivalent non-orthogonal deviation angle parameters, and substitutes them into the optical axis pointing transmission model containing non-orthogonal errors, thereby eliminating the influence of non-orthogonality on optical axis pointing errors.

[0050] Preferably, the module M1 includes:

[0051] First, define the pitch axis reference coordinate system, with the origin O. fLocated at the center of the pitch axis, +Z f The axis is perpendicular to the turntable mounting surface and parallel to the direction of the laser terminal's optical axis; +Y f The axis is parallel to the pitch axis; X f axis and Y f Axis and Z f The axes form a right-handed rectangular coordinate system; according to the definition of the pitch axis reference coordinate system, the pitch mechanism revolves around the Y-axis. f The shaft rotates;

[0052] Then define the azimuth axis reference coordinate system, with the origin O. c Located at the center of the mounting area between the azimuth axis and the mounting surface, +X c The axis is parallel to the azimuth axis; when the azimuth axis is at zero, +Y c The axis is parallel to the pitch axis; X c axis and Y c Axis and Z c The axes form a right-handed rectangular coordinate system; according to the definition of the azimuth axis reference coordinate system, the azimuth mechanism revolves around the X-axis. c The shaft rotates;

[0053] Finally, define a two-dimensional rotary table reference coordinate system, with the origin O. b Located at the lower right corner of the mounting surface; when the azimuth axis is at zero, the X-axis of the two-dimensional turntable reference coordinate system... b Axis, Y b Axis, Z b X-axis and azimuth axis reference coordinate system c Axis, Y c Axis, Z c The axes are parallel.

[0054] Preferably, the module M2 includes:

[0055] First, we analyze the influence of the pitch axis on the optical axis pointing of the laser terminal. The optical axis vector of the laser terminal is projected onto the azimuth axis reference coordinate system, and the expression is as follows:

[0056]

[0057] Then, considering the effect of azimuth axis rotation on the optical axis pointing of the laser terminal, the optical axis vector of the optical terminal is projected onto the two-dimensional turntable axis reference coordinate system, and the expression is as follows:

[0058]

[0059] Combining the two equations, we get:

[0060]

[0061] In the formula, This is the projection of the laser terminal optical axis vector onto the pitch axis reference coordinate system; β is the projection of the laser terminal optical axis vector onto the azimuth axis reference coordinate system; β is the pitch axis rotation angle. α is the projection of the laser terminal optical axis vector onto the two-dimensional turntable axis reference coordinate system; α is the azimuth axis rotation angle.

[0062] Preferably, the module M3 includes:

[0063] The expression for the optical axis pointing transfer model containing non-orthogonal errors is:

[0064]

[0065] In the formula, R f The pitch axis non-orthogonal transfer matrix is ​​expressed as follows:

[0066]

[0067] In the formula, X f The pitch axis is the non-orthogonal rotation error relative to the X-axis, Y f Z represents the non-orthogonal rotation error of the pitch axis relative to the Y-axis. f X represents the non-orthogonal rotation error of the pitch axis relative to the Z-axis. f Y f Z f These are the three equivalent non-orthogonal deviation angle parameters of the pitch axis;

[0068] R c The azimuth axis non-orthogonal transfer matrix is ​​expressed as follows:

[0069]

[0070] In the formula, X c The azimuth axis is the non-orthogonal rotation error relative to the X-axis, Y c Z represents the non-orthogonal rotation error of the azimuth axis relative to the Y-axis. c The non-orthogonal rotation error of the azimuth axis relative to the Z-axis; X c Y c Z c These are the three equivalent non-orthogonal deviation angle parameters of the azimuth axis.

[0071] Preferably, the module M4 includes:

[0072] The optical axis pointing transfer model containing non-orthogonal errors is simplified as follows:

[0073]

[0074] In the formula, X f Z f For the simplified pitch axis equivalent non-orthogonal deviation angle parameter, Y c Zc The simplified azimuth axis is equivalent to the non-orthogonal deviation angle parameter;

[0075] N x (α) is the azimuth axis transfer matrix, expressed as:

[0076]

[0077] N y (β) is the pitch axis transfer matrix, expressed as:

[0078]

[0079] Solve for the simplified equivalent non-orthogonal deviation angle parameter and substitute it into the optical axis pointing transmission model containing non-orthogonal error to eliminate the influence of non-orthogonality on optical axis pointing error.

[0080] Compared with the prior art, the present invention has the following beneficial effects:

[0081] This invention proposes a non-orthogonal analysis and correction method for a two-dimensional turntable in a laser terminal. By analyzing the influence of the non-orthogonality of the two-dimensional turntable on the optical axis orientation through geometric modeling, a non-orthogonal solution method is proposed, which can adapt to correction under a wide range of rotation. Compared with the traditional linear fitting method, it fundamentally solves the influence of non-orthogonality and achieves higher implementation accuracy. Attached Figure Description

[0082] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0083] Figure 1 This is a schematic diagram of the coordinate system definition of the two-dimensional turntable of the laser terminal;

[0084] Figure 2 It is the relationship between optical axis pointing error and pitch axis rotation angle (azimuth axis zero position);

[0085] Figure 3 It is the relationship between the optical axis pointing error and the pitch axis rotation angle (azimuth axis offset 30°);

[0086] Figure 4 It is the optical axis pointing error (azimuth axis zero position) after non-orthogonal correction;

[0087] Figure 5 The optical axis pointing error after non-orthogonal correction (azimuth axis offset 30°). Detailed Implementation

[0088] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0089] Example 1

[0090] This invention provides a method for non-orthogonal analysis and correction of a two-dimensional turntable for a laser terminal, comprising the following steps:

[0091] Step S1: Establish a two-dimensional turntable reference coordinate system and describe the rotation mode of the two-dimensional turntable;

[0092] Step S2: Establish an optical axis pointing transfer model without non-orthogonal errors using the geometric transfer method;

[0093] Step S3: Add a non-orthogonal error transfer matrix to the optical axis pointing transfer model to establish an optical axis pointing transfer model containing non-orthogonal errors;

[0094] Step S4: Establish a calibration method based on the optical axis pointing transmission model containing non-orthogonal errors to achieve nonlinear correction under a wide range of rotation angles.

[0095] Step S1 includes:

[0096] like Figure 1 First, define the pitch axis reference coordinate system, with the origin O. f Located at the center of the pitch axis, +Z f The axis is perpendicular to the turntable mounting surface and parallel to the direction of the laser terminal's optical axis; +Y f The axis is parallel to the pitch axis; X f axis and Y f Axis and Z f The axes form a right-handed rectangular coordinate system. According to the definition of the pitch axis reference coordinate system, the pitch mechanism revolves around the Y-axis. f The shaft rotates.

[0097] Then define the azimuth axis reference coordinate system, with the origin O. c Located at the center of the mounting area between the azimuth axis and the mounting surface, +X c The axis is parallel to the azimuth axis; when the azimuth axis is at zero, +Y c The axis is parallel to the pitch axis; X c axis and Y c Axis and Z c The axes form a right-handed rectangular coordinate system. According to the definition of the azimuth axis reference coordinate system, the azimuth mechanism revolves around the X-axis. c The shaft rotates.

[0098] Finally, define a two-dimensional rotary table reference coordinate system, with the origin O. b Located at the lower right corner of the mounting surface. When the azimuth axis is at zero, the X-axis of the two-dimensional turntable reference coordinate system... b Axis, Y b Axis, Z b X-axis and azimuth axis reference coordinate system c Axis, Y c Axis, Z c The axes are parallel.

[0099] Step S2 includes:

[0100] First, we analyze the influence of the pitch axis on the optical axis pointing of the laser terminal. The optical axis vector of the laser terminal is projected onto the azimuth axis reference coordinate system, and the expression is as follows:

[0101]

[0102] In the above formula, This is the projection of the laser terminal optical axis vector onto the pitch axis reference coordinate system; β is the projection of the laser terminal optical axis vector onto the azimuth axis reference coordinate system; β is the pitch axis rotation angle.

[0103] Next, considering the influence of azimuth axis rotation on the optical axis pointing of the laser terminal, the optical axis vector of the optical terminal is projected onto the two-dimensional turntable axis reference coordinate system, as shown in the following expression:

[0104]

[0105] In the above formula, This is the projection of the laser terminal optical axis vector onto the azimuth axis reference coordinate system; α is the projection of the laser terminal optical axis vector onto the two-dimensional turntable axis reference coordinate system; α is the azimuth axis rotation angle.

[0106] Combining the above equations, we get:

[0107]

[0108] In the above formula, α is the azimuth axis rotation angle, and β is the pitch axis rotation angle. This represents the projection of the laser terminal optical axis vector onto the pitch axis reference coordinate system. This is the projection of the laser terminal optical axis vector onto the azimuth axis reference coordinate system.

[0109] Step S3 includes:

[0110] The expression for the optical axis pointing transfer model containing non-orthogonal errors is:

[0111]

[0112] In the above formula, Rf The pitch axis non-orthogonal transfer matrix is ​​expressed as follows:

[0113]

[0114] In the above formula, X f The pitch axis is the non-orthogonal rotation error relative to the X-axis, Y f Z represents the non-orthogonal rotation error of the pitch axis relative to the Y-axis. f This represents the non-orthogonal rotation error of the pitch axis relative to the Z-axis.

[0115] X f Y f Z f These are the three equivalent non-orthogonal deviation angle parameters of the pitch axis.

[0116] R c The azimuth axis non-orthogonal transfer matrix is ​​expressed as follows:

[0117]

[0118] In the above formula, X c The azimuth axis is the non-orthogonal rotation error relative to the X-axis, Y c Z represents the non-orthogonal rotation error of the azimuth axis relative to the Y-axis. c This represents the non-orthogonal rotation error of the azimuth axis relative to the Z-axis.

[0119] X c Y c Z c These are the three equivalent non-orthogonal deviation angle parameters of the azimuth axis.

[0120] According to the optical axis pointing transmission model of non-orthogonal error, due to the influence of non-orthogonality of the rotation axis, the optical axis pointing error is inconsistent when the two-dimensional rotation angle is rotated to different positions. Furthermore, the pitch axis and azimuth axis of the two-dimensional turntable are coupled to each other, and the rotation angle of the azimuth axis also affects the non-orthogonality of the pitch axis.

[0121] A set of non-orthogonal parameters is randomly generated. When the azimuth angle is zero, the relationship between the laser terminal optical axis pointing error and the pitch axis can be obtained as shown in the attached figure. Figure 2 As shown, the optical axis pointing error varies with the pitch axis. When the azimuth offset is 30°, the relationship between the laser terminal's optical axis pointing error and the pitch axis is shown in the attached figure. Figure 3 As shown, the variation patterns of optical axis pointing error and pitch axis rotation angle are inconsistent with the variation patterns when the azimuth angle is at zero, indicating that the non-orthogonality of the pitch axis and azimuth axis has a mutual coupling characteristic.

[0122] Step 4 includes:

[0123] Step 3 introduces the optical axis pointing transfer model with non-orthogonal errors. The model contains 6 equivalent non-orthogonal deviation angle parameters (3 for azimuth axis and 3 for pitch axis). In order to facilitate model correction, the equivalent non-orthogonal deviation angle parameters can be optimized according to the physical meaning of the rotation axis.

[0124] According to the definition of a coordinate system, the rotation axis of the pitch axis is related to the Y-axis of the pitch axis reference coordinate system. f Since the axes are parallel, the non-orthogonal rotation error of the pitch axis relative to the Y-axis will not cause a non-orthogonal change in the optical axis direction; similarly, the rotation axis of the azimuth axis is parallel to the X-axis of the azimuth axis reference coordinate system. c Since the axes are parallel, the non-orthogonal rotation error of the azimuth axis relative to the X-axis will not cause a non-orthogonal change in the optical axis pointing direction. Based on the above analysis, the optical axis pointing direction transmission model containing non-orthogonal errors can be simplified as follows:

[0125]

[0126] In the above formula, X f Z f For the simplified pitch axis equivalent non-orthogonal deviation angle parameter, Y c Z c The simplified azimuth axis is equivalent to the non-orthogonal deviation angle parameter.

[0127] N x (α) is the azimuth axis transfer matrix, expressed as:

[0128]

[0129] N y (β) is the pitch axis transfer matrix, expressed as:

[0130]

[0131] To correct the influence of non-orthogonal parameters on the laser terminal pointing, it is necessary to solve for the simplified equivalent non-orthogonal deviation angle parameters. Under the influence of non-orthogonality, the optical axis pointing deviations are different for different rotation angles. Therefore, during the calculation, it is necessary to drive the two-dimensional turntable to point at different angles and establish equivalent equations on-orbit using geometric calibration points such as stars and landmarks to solve for the non-orthogonal parameters.

[0132] Finally, by substituting the four simplified equivalent non-orthogonal deviation angle parameters obtained from the solution into the optical axis pointing transmission model, the influence of non-orthogonality on the optical axis pointing error can be eliminated. (Appendix) Figure 4 The optical axis pointing error after non-orthogonal correction, when the azimuth axis is at zero, is given. Figure 5 The optical axis pointing error after non-orthogonal correction with an azimuth axis offset of 30° is presented. The calculation results show that the optical axis pointing error is significantly reduced after non-orthogonal correction, indicating the effectiveness of this invention.

[0133] Example 2

[0134] The present invention also provides a non-orthogonal analysis and correction system for a two-dimensional turntable of a laser terminal. The non-orthogonal analysis and correction system for a two-dimensional turntable of a laser terminal can be implemented by executing the process steps of the non-orthogonal analysis and correction method for a two-dimensional turntable of a laser terminal. That is, those skilled in the art can understand the non-orthogonal analysis and correction method for a two-dimensional turntable of a laser terminal as a preferred embodiment of the non-orthogonal analysis and correction system for a two-dimensional turntable of a laser terminal.

[0135] The non-orthogonal analysis and correction system for a two-dimensional turntable of a laser terminal provided by the present invention includes:

[0136] Module M1: Establishes the reference coordinate system for the two-dimensional turntable of the laser terminal and describes the rotation mode of the two-dimensional turntable of the laser terminal;

[0137] Module M2: Establishes an optical axis pointing transfer model without non-orthogonal errors using the geometric transfer method;

[0138] Module M3: Add a non-orthogonal error transfer matrix to the optical axis pointing transfer model to establish an optical axis pointing transfer model containing non-orthogonal errors;

[0139] Module M4: Drives the two-dimensional turntable to point at different angles. On-orbit, it uses geometric calibration points to establish equivalent equations, solves for equivalent non-orthogonal deviation angle parameters, and substitutes them into the optical axis pointing transmission model containing non-orthogonal errors, thereby eliminating the influence of non-orthogonality on optical axis pointing errors.

[0140] The module M1 includes:

[0141] First, define the pitch axis reference coordinate system, with the origin O. f Located at the center of the pitch axis, +Z f The axis is perpendicular to the turntable mounting surface and parallel to the direction of the laser terminal's optical axis; +Y f The axis is parallel to the pitch axis; X f axis and Y f Axis and Z f The axes form a right-handed rectangular coordinate system; according to the definition of the pitch axis reference coordinate system, the pitch mechanism revolves around the Y-axis. f The shaft rotates;

[0142] Then define the azimuth axis reference coordinate system, with the origin O. c Located at the center of the mounting area between the azimuth axis and the mounting surface, +X c The axis is parallel to the azimuth axis; when the azimuth axis is at zero, +Y c The axis is parallel to the pitch axis; X c axis and Y c Axis and Z cThe axes form a right-handed rectangular coordinate system; according to the definition of the azimuth axis reference coordinate system, the azimuth mechanism revolves around the X-axis. c The shaft rotates;

[0143] Finally, define a two-dimensional rotary table reference coordinate system, with the origin O. b Located at the lower right corner of the mounting surface; when the azimuth axis is at zero, the X-axis of the two-dimensional turntable reference coordinate system... b Axis, Y b Axis, Z b X-axis and azimuth axis reference coordinate system c Axis, Y c Axis, Z c The axes are parallel.

[0144] The module M2 includes:

[0145] First, we analyze the influence of the pitch axis on the optical axis pointing of the laser terminal. The optical axis vector of the laser terminal is projected onto the azimuth axis reference coordinate system, and the expression is as follows:

[0146]

[0147] Then, considering the effect of azimuth axis rotation on the optical axis pointing of the laser terminal, the optical axis vector of the optical terminal is projected onto the two-dimensional turntable axis reference coordinate system, and the expression is as follows:

[0148]

[0149] Combining the two equations, we get:

[0150]

[0151] In the formula, This is the projection of the laser terminal optical axis vector onto the pitch axis reference coordinate system; β is the projection of the laser terminal optical axis vector onto the azimuth axis reference coordinate system; β is the pitch axis rotation angle. α is the projection of the laser terminal optical axis vector onto the two-dimensional turntable axis reference coordinate system; α is the azimuth axis rotation angle.

[0152] The module M3 includes:

[0153] The expression for the optical axis pointing transfer model containing non-orthogonal errors is:

[0154]

[0155] In the formula, R f The pitch axis non-orthogonal transfer matrix is ​​expressed as follows:

[0156]

[0157] In the formula, X fThe pitch axis is the non-orthogonal rotation error relative to the X-axis, Y f Z represents the non-orthogonal rotation error of the pitch axis relative to the Y-axis. f X represents the non-orthogonal rotation error of the pitch axis relative to the Z-axis. f Y f Z f These are the three equivalent non-orthogonal deviation angle parameters of the pitch axis;

[0158] R c The azimuth axis non-orthogonal transfer matrix is ​​expressed as follows:

[0159]

[0160] In the formula, X c The azimuth axis is the non-orthogonal rotation error relative to the X-axis, Y c Z represents the non-orthogonal rotation error of the azimuth axis relative to the Y-axis. c The non-orthogonal rotation error of the azimuth axis relative to the Z-axis; X c Y c Z c These are the three equivalent non-orthogonal deviation angle parameters of the azimuth axis.

[0161] The module M4 includes:

[0162] The optical axis pointing transfer model containing non-orthogonal errors is simplified as follows:

[0163]

[0164] In the formula, X f Z f For the simplified pitch axis equivalent non-orthogonal deviation angle parameter, Y c Z c The simplified azimuth axis is equivalent to the non-orthogonal deviation angle parameter;

[0165] N x (α) is the azimuth axis transfer matrix, expressed as:

[0166]

[0167] N y (β) is the pitch axis transfer matrix, expressed as:

[0168]

[0169] Solve for the simplified equivalent non-orthogonal deviation angle parameter and substitute it into the optical axis pointing transmission model containing non-orthogonal error to eliminate the influence of non-orthogonality on optical axis pointing error.

[0170] Those skilled in the art will understand that, in addition to implementing the system, apparatus, and their modules provided by this invention in purely computer-readable program code, the same program can be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, the system, apparatus, and their modules provided by this invention can be considered a hardware component, and the modules included therein for implementing various programs can also be considered structures within the hardware component; alternatively, modules for implementing various functions can be considered both software programs implementing the method and structures within the hardware component.

[0171] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A method for non-orthogonal analysis and correction of a two-dimensional turntable for a laser terminal, characterized in that, include: Step S1: Establish a reference coordinate system for the two-dimensional turntable of the laser terminal and describe the rotation mode of the two-dimensional turntable of the laser terminal; Step S2: Establish an optical axis pointing transfer model without non-orthogonal errors using the geometric transfer method; Step S3: Add a non-orthogonal error transfer matrix to the optical axis pointing transfer model to establish an optical axis pointing transfer model containing non-orthogonal errors; Step S4: Drive the two-dimensional turntable to point at different angles, establish equivalent equations on track using geometric calibration points, solve for the equivalent non-orthogonal deviation angle parameters and substitute them into the optical axis pointing transmission model containing non-orthogonal errors, thereby eliminating the influence of non-orthogonality on optical axis pointing errors; Step S1 includes: First, define the pitch axis reference coordinate system, with the origin O. f Located at the center of the pitch axis, +Z f The axis is perpendicular to the turntable mounting surface and parallel to the direction of the laser terminal's optical axis; +Y f The axis is parallel to the pitch axis; X f axis and Y f Axis and Z f The axes form a right-handed rectangular coordinate system; according to the definition of the pitch axis reference coordinate system, the pitch mechanism revolves around the Y-axis. f The shaft rotates; Then define the azimuth axis reference coordinate system, with the origin O. c Located at the center of the mounting area between the azimuth axis and the mounting surface, +X c The axis is parallel to the azimuth axis; when the azimuth axis is at zero, +Y c The axis is parallel to the pitch axis; X c axis and Y c Axis and Z c The axes form a right-handed rectangular coordinate system; according to the definition of the azimuth axis reference coordinate system, the azimuth mechanism revolves around the X-axis. c The shaft rotates; Finally, define a two-dimensional rotary table reference coordinate system, with the origin O. b Located at the lower right corner of the mounting surface; when the azimuth axis is at zero, the X-axis of the two-dimensional turntable reference coordinate system... b Axis, Y b Axis, Z b X-axis and azimuth axis reference coordinate system c Axis, Y c Axis, Z c The axes are parallel; Step S2 includes: First, we analyze the influence of the pitch axis on the optical axis pointing of the laser terminal. The optical axis vector of the laser terminal is projected onto the azimuth axis reference coordinate system, and the expression is as follows: Then, considering the effect of azimuth axis rotation on the optical axis pointing of the laser terminal, the optical axis vector of the optical terminal is projected onto the two-dimensional turntable axis reference coordinate system, and the expression is as follows: Combining the two equations, we get: In the formula, This is the projection of the laser terminal optical axis vector onto the pitch axis reference coordinate system; β is the projection of the laser terminal optical axis vector onto the azimuth axis reference coordinate system; β is the pitch axis rotation angle. α is the projection of the laser terminal optical axis vector onto the two-dimensional turntable axis reference coordinate system; α is the azimuth axis rotation angle; Step S3 includes: The expression for the optical axis pointing transfer model containing non-orthogonal errors is: In the formula, R f The pitch axis non-orthogonal transfer matrix is ​​expressed as follows: In the formula, X f The pitch axis is the non-orthogonal rotation error relative to the X-axis, Y f Z represents the non-orthogonal rotation error of the pitch axis relative to the Y-axis. f X represents the non-orthogonal rotation error of the pitch axis relative to the Z-axis. f Y f Z f These are the three equivalent non-orthogonal deviation angle parameters of the pitch axis; R c The azimuth axis non-orthogonal transfer matrix is ​​expressed as follows: In the formula, X c The azimuth axis is the non-orthogonal rotation error relative to the X-axis, Y c Z represents the non-orthogonal rotation error of the azimuth axis relative to the Y-axis. c The non-orthogonal rotation error of the azimuth axis relative to the Z-axis; X c Y c Z c These are the three equivalent non-orthogonal deviation angle parameters of the azimuth axis; Step S4 includes: The optical axis pointing transfer model containing non-orthogonal errors is simplified as follows: In the formula, X f Z f For the simplified pitch axis equivalent non-orthogonal deviation angle parameter, Y c Z c The simplified azimuth axis is equivalent to the non-orthogonal deviation angle parameter; N x (α) is the azimuth axis transfer matrix, expressed as: N y (β) is the pitch axis transfer matrix, expressed as: Solve for the simplified equivalent non-orthogonal deviation angle parameter and substitute it into the optical axis pointing transmission model containing non-orthogonal error to eliminate the influence of non-orthogonality on optical axis pointing error.

2. A non-orthogonal analysis and correction system for a two-dimensional turntable of a laser terminal, characterized in that, include: Module M1: Establishes the reference coordinate system for the two-dimensional turntable of the laser terminal and describes the rotation mode of the two-dimensional turntable of the laser terminal; Module M2: Establishes an optical axis pointing transfer model without non-orthogonal errors using the geometric transfer method; Module M3: Add a non-orthogonal error transfer matrix to the optical axis pointing transfer model to establish an optical axis pointing transfer model containing non-orthogonal errors; Module M4: Drives the two-dimensional turntable to point at different angles. On-orbit, it uses geometric calibration points to establish equivalent equations, solves for equivalent non-orthogonal deviation angle parameters, and substitutes them into the optical axis pointing transmission model containing non-orthogonal errors, thereby eliminating the influence of non-orthogonality on optical axis pointing errors. The module M1 includes: First, define the pitch axis reference coordinate system, with the origin O. f Located at the center of the pitch axis, +Z f The axis is perpendicular to the turntable mounting surface and parallel to the direction of the laser terminal's optical axis; +Y f The axis is parallel to the pitch axis; X f axis and Y f Axis and Z f The axes form a right-handed rectangular coordinate system; according to the definition of the pitch axis reference coordinate system, the pitch mechanism revolves around the Y-axis. f The shaft rotates; Then define the azimuth axis reference coordinate system, with the origin O. c Located at the center of the mounting area between the azimuth axis and the mounting surface, +X c The axis is parallel to the azimuth axis; when the azimuth axis is at zero, +Y c The axis is parallel to the pitch axis; X c axis and Y c Axis and Z c The axes form a right-handed rectangular coordinate system; according to the definition of the azimuth axis reference coordinate system, the azimuth mechanism revolves around the X-axis. c The shaft rotates; Finally, define a two-dimensional rotary table reference coordinate system, with the origin O. b Located at the lower right corner of the mounting surface; when the azimuth axis is at zero, the X-axis of the two-dimensional turntable reference coordinate system... b Axis, Y b Axis, Z b X-axis and azimuth axis reference coordinate system c Axis, Y c Axis, Z c The axes are parallel; The module M2 includes: First, we analyze the influence of the pitch axis on the optical axis pointing of the laser terminal. The optical axis vector of the laser terminal is projected onto the azimuth axis reference coordinate system, and the expression is as follows: Then, considering the effect of azimuth axis rotation on the optical axis pointing of the laser terminal, the optical axis vector of the optical terminal is projected onto the two-dimensional turntable axis reference coordinate system, and the expression is as follows: Combining the two equations, we get: In the formula, This is the projection of the laser terminal optical axis vector onto the pitch axis reference coordinate system; β is the projection of the laser terminal optical axis vector onto the azimuth axis reference coordinate system; β is the pitch axis rotation angle. α is the projection of the laser terminal optical axis vector onto the two-dimensional turntable axis reference coordinate system; α is the azimuth axis rotation angle; The module M3 includes: The expression for the optical axis pointing transfer model containing non-orthogonal errors is: In the formula, R f The pitch axis non-orthogonal transfer matrix is ​​expressed as follows: In the formula, X f The pitch axis is the non-orthogonal rotation error relative to the X-axis, Y f Z represents the non-orthogonal rotation error of the pitch axis relative to the Y-axis. f X represents the non-orthogonal rotation error of the pitch axis relative to the Z-axis. f Y f Z f These are the three equivalent non-orthogonal deviation angle parameters of the pitch axis; R c The azimuth axis non-orthogonal transfer matrix is ​​expressed as follows: In the formula, X c The azimuth axis is the non-orthogonal rotation error relative to the X-axis, Y c Z represents the non-orthogonal rotation error of the azimuth axis relative to the Y-axis. c The non-orthogonal rotation error of the azimuth axis relative to the Z-axis; X c Y c Z c These are the three equivalent non-orthogonal deviation angle parameters of the azimuth axis; The module M4 includes: The optical axis pointing transfer model containing non-orthogonal errors is simplified as follows: In the formula, X f Z f For the simplified pitch axis equivalent non-orthogonal deviation angle parameter, Y c Z c The simplified azimuth axis is equivalent to the non-orthogonal deviation angle parameter; N x (α) is the azimuth axis transfer matrix, expressed as: N y (β) is the pitch axis transfer matrix, expressed as: Solve for the simplified equivalent non-orthogonal deviation angle parameter and substitute it into the optical axis pointing transmission model containing non-orthogonal error to eliminate the influence of non-orthogonality on optical axis pointing error.

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