An airborne optoelectronic platform inertial measurement unit calibration method

Abstract

The application provides an airborne optoelectronic platform inertial measurement unit calibration method, and belongs to the technical field of precise optomechanical adjustment. The method comprises the following steps: S1: detecting and adjusting the intersection degree of the azimuth and pitch axis system position of the airborne platform; S2: calibrating and precision detecting the rotation shaft of the azimuth and pitch axis system of the airborne platform; S3: detecting and adjusting the perpendicularity of the azimuth and pitch axis system of the airborne platform; S4: detecting and adjusting the orthogonality between the optical axis of the optoelectronic platform and the axis system; and S5: calibrating the deviation of the inertial measurement unit coordinate system. The method provided by the application completes the precise adjustment of the axis system of the airborne platform and the deviation calibration of the inertial measurement unit through the above series of optomechanical adjustment steps, realizes the orthogonal coordinate system adjustment and positioning of the axis system and the optical axis of the airborne optoelectronic platform, tests the deviation value of the inertial measurement unit and the orthogonal coordinate system, and then feeds back to the data processing subsystem to realize the geometric space related calculation.

Description

Technical Field

[0001] This invention relates to the field of precision optomechanical assembly and adjustment technology, and in particular provides a calibration method for the inertial measurement unit of an airborne optoelectronic platform. Background Technology

[0002] Currently, most airborne optoelectronic detection and countermeasures payloads adopt a two-axis, two-frame or two-axis, four-frame configuration. A common design involves highly integrated multi-band sensors on a stable platform. This platform is connected to the outer casing via azimuth and pitch axes, allowing for rotation and detection at any position in space through the rotation of these two axes. A typical airborne optoelectronic platform configuration is shown in the appendix. Figure 1 As shown, it mainly consists of an optoelectronic stabilization platform 1, an azimuth axis system 2, a pitch axis system 3, and a pitch frame 4. The azimuth axis system 2 and the pitch axis system 3 are each composed of two half-axises, each with its own rotation axis. These rotation axes are intersecting and perpendicular in space, allowing for separate detection and adjustment. Furthermore, to ensure the platform's optical axis is identifiable and monitorable, a reference reflective surface for optical axis identification was reserved during platform assembly. This reflective surface has been precisely adjusted and fixed, and will serve as the optical axis reference for the platform's optical system.

[0003] According to navigation control principles, inertial navigation equipment such as aircraft requires motion control, and its attitude needs precise displacement calculation. An inertial measurement unit (IMU) is a strapdown inertial navigation system that can provide angular velocity and acceleration information. An IMU is a device that measures an object's three-axis attitude angles or angular rates and acceleration. A typical IMU contains three single-axis accelerometers and three single-axis gyroscopes. The accelerometers detect the object's acceleration signals along its three independent axes in the carrier coordinate system, while the gyroscopes detect the angular velocity signals of the carrier relative to the navigation coordinate system. By measuring the object's angular velocity and acceleration in three-dimensional space, the object's spatial attitude can be calculated, which has significant application value in navigation. Typically, the IMU is mounted at the center of gravity of an airborne opto-stabilized platform. After initial assembly, the IMU has an angular deviation error from the coordinate system formed by the axes and optical axes. Therefore, it is necessary to accurately measure this error and calibrate the IMU. Summary of the Invention

[0004] The purpose of this application is to provide a calibration method for an inertial measurement unit (IMU) of an airborne optoelectronic platform. This method calibrates the IMU by detecting and adjusting the intersection of the azimuth and pitch axes of the airborne platform, detecting and calibrating the rotation accuracy of the two axes and the rotation axis, detecting and adjusting the perpendicularity of the two axes, detecting and adjusting the orthogonality of the platform's optical axis and the axes, and calibrating the coordinate system error of the IMU.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a calibration method for an inertial measurement unit of an airborne optoelectronic platform, wherein the airborne optoelectronic platform includes an optoelectronic stabilization platform, an azimuth axis system, a pitch axis system, and a pitch frame disposed on the optoelectronic stabilization platform, wherein the azimuth axis system and the pitch axis system are each composed of two half-axises, each having a rotation axis, and the rotation axes are intersecting and perpendicular in spatial position; the method includes:

[0006] S1: Detect and adjust the intersection of the azimuth and pitch axis positions of the airborne platform;

[0007] S2: Calibrate and test the accuracy of the rotation axis of the azimuth and pitch axis system of the airborne platform;

[0008] S3: Detect and adjust the verticality of the azimuth and pitch axis system of the airborne platform;

[0009] S4: Detection and calibration of the orthogonality of the optical axis and axis system of the optoelectronic platform;

[0010] S5: Calibrate the coordinate system deviation of the inertial measurement unit.

[0011] The airborne optoelectronic platform inertial measurement unit calibration method provided by this invention also has the following technical feature: S1 includes:

[0012] S1.1: The airborne optoelectronic platform is mounted on the marble platform using adjustment and support fixtures, with the azimuth axis systems on both sides placed horizontally;

[0013] S1.2: Use a height gauge to detect the center height of the half-axis rotation axis on both sides of the azimuth axis system, and adjust the attitude of the photoelectric stabilization platform to make the azimuth axis parallel to the marble platform plane;

[0014] S1.3: Use an altimeter to detect the center height of the rotation axis of the half-shaft on both sides of the pitch axis system. Adjust the height of the half-shaft on both sides of the pitch axis system to be the same by rotating it up and down, and record the vertical height H1 from the center to the plane of the altimeter.

[0015] S1.4: Rotate the pitch axis half-axis counterclockwise by 180° around the azimuth axis, repeat S1.3 to record the center and adjust the vertical height H2 to the plane of the altimeter;

[0016] S1.5: Calculate the difference between the vertical height H1 from the center to the altimeter plane and the adjusted vertical height H2 from the center to the altimeter plane. This difference H1-H2 is the degree of intersection of the axis positions.

[0017] The calibration method for the inertial measurement unit of the airborne optoelectronic platform provided by the present invention also has the following technical features: S1 further includes comparing the intersection degree of the axis system position with the intersection degree index of the azimuth and pitch axis system position of the airborne optoelectronic platform. If the index requirements are not met, the positions of the half-axis systems on both sides of the pitch axis system are adjusted and S1.3-S1.5 are repeated.

[0018] The airborne optoelectronic platform inertial measurement unit calibration method provided by this invention also has the following technical feature: S2 includes:

[0019] S2.1: Assemble the adapter tooling onto the corresponding half-shaft of the azimuth axis system and the pitch axis system, so that the azimuth axis system and the pitch axis system are connected and secured.

[0020] S2.2: Connect the multidimensional adjustable mirror to the adapter fixture, and set the first photoelectric autocollimating tube and the second photoelectric autocollimating tube at the working distance in front of the multidimensional adjustable mirror. Perform coarse collimation through the laser collimating image finder of the multidimensional adjustable mirror, and adjust the first photoelectric autocollimating tube and the second photoelectric autocollimating tube so that the autocollimated image of the multidimensional adjustable mirror enters the detection field of view.

[0021] S2.3: Fine-tune the first and second photoelectric autocollimators from the collimated image to the center position, rotate the axis system at a constant speed, collect image points in real time, draw the fitting circle, and obtain the angular deflection accuracy;

[0022] S2.4: Adjust the azimuth and pitch angles of the multi-dimensional adjustable mirror to move the image point toward the center of the circle. Repeat S2.3 until the angular deflection accuracy is minimized. At this point, the normal of the multi-dimensional adjustable mirror surface is the axis of rotation. The azimuth and pitch axis system rotation axis is calibrated and its accuracy is tested.

[0023] The airborne optoelectronic platform inertial measurement unit calibration method provided by the present invention also has the following technical features: S3 includes: placing a pentaprism at the intersection of the first optoelectronic autocollimating tube and the second optoelectronic autocollimating tube, the incident surface of the pentaprism being collimated with the first optoelectronic autocollimating tube, the light beam being observed through the second optoelectronic autocollimating tube after exiting through the pentaprism, and the autocollimation image deviation value at this time is the axis perpendicularity deviation.

[0024] The airborne optoelectronic platform inertial measurement unit calibration method provided by the present invention also has the following technical feature: S3 further includes adjusting the verticality deviation of the axis system by adjusting the position of the azimuth axis system.

[0025] The airborne optoelectronic platform inertial measurement unit calibration method provided by this invention also has the following technical feature: S4 includes:

[0026] S4.1: Two reflecting surfaces are set outside the inertial measurement unit to replace its working axis. The two reflecting surfaces include the reference optical reflecting surface of the first axis of the measurement unit and the reference optical reflecting surface of the second axis of the measurement unit.

[0027] S4.2: Place a pentaprism in front of the first photoelectric autocollimating tube, and adjust the incident surface of the pentaprism to be collimated with the first photoelectric autocollimating tube to ensure that the emitted beam of the pentaprism and the incident beam are in the same horizontal plane. Set up a third photoelectric autocollimating tube behind the emitted beam. The third photoelectric autocollimating tube is installed in the second axis reference optical reflection envelope area of ​​the measurement unit. Adjust the third photoelectric autocollimating tube to make it orthogonally collimated with the first photoelectric autocollimating tube.

[0028] S4.3: Remove the pentaprism, set up a fourth photoelectric autocollimating tube in front of the third photoelectric autocollimating tube, and adjust the azimuth and pitch angle of the fourth photoelectric autocollimating tube to make it collimated with the third photoelectric autocollimating tube;

[0029] S4.4: A large-aperture standard plane mirror is set up in front of the first photoelectric autocollimating light tube. The large-aperture standard plane mirror is collimated with the first photoelectric autocollimating light tube. A fifth photoelectric autocollimating light tube is set up in the first axis reference optical reflection envelope area of ​​the measurement unit. The fifth photoelectric autocollimating light tube is adjusted to collimate with the large-aperture standard plane mirror. Then the orthogonality detection and calibration of the optical axis and axis system of the photoelectric platform is completed.

[0030] The airborne optoelectronic platform inertial measurement unit calibration method provided by this invention also has the following technical feature: S5 includes:

[0031] S5.1: Install the inertial measurement unit at the center of gravity of the photoelectric stabilization platform, and place it on the two-dimensional adjustment platform after assembly;

[0032] S5.2: Adjust the azimuth and pitch angle of the two-dimensional platform so that the first photoelectric autocollimating tube and the second photoelectric autocollimating tube are respectively collimated with the multi-dimensional adjustable reflector;

[0033] S5.3: Adjust the position of the photoelectric stabilization platform so that its optical axis recognition reference reflective surface is aligned with the fourth photoelectric autocollimating light tube;

[0034] S5.4: The deviation values ​​of the first axis reference optical reflector and the second axis reference optical reflector of the inertial measurement unit are directly observed through the third photoelectric autocollimator and the fifth photoelectric autocollimator, and fed back to the data processing subsystem to complete the deviation calibration of the inertial measurement unit.

[0035] Beneficial effects

[0036] The method provided by this invention performs the following steps: detection and adjustment of the intersection of the azimuth and pitch axes of the airborne platform; detection and calibration of the rotation accuracy and rotation axis of the two axes; detection and adjustment of the perpendicularity of the two axes; detection and adjustment of the orthogonality between the platform's optical axis and the axis system; and calibration of the coordinate system error of the inertial measurement unit. Through this series of optomechanical calibration steps, the precise adjustment of the airborne platform's axis system and the deviation calibration of the inertial measurement unit are simultaneously completed. This achieves the adjustment and positioning of the orthogonal coordinate system between the airborne optoelectronic platform's axis system and optical axis, tests the deviation value between the inertial measurement unit and this orthogonal coordinate system, and then feeds it back to the data processing subsystem to perform geometric spatial correlation calculations. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a diagram illustrating the composition of the airborne optoelectronic platform mentioned in this invention.

[0039] Figure 2 This is a schematic diagram of the inertial measurement unit structure mentioned in this invention;

[0040] Figure 3 This is a schematic diagram illustrating the principle of shaft system position intersection detection.

[0041] Appendix Figure 4 This is a schematic diagram of the shaft rotation accuracy detection principle.

[0042] Appendix Figure 5 This is a schematic diagram illustrating the principle of shaft perpendicularity detection.

[0043] Appendix Figure 6 Establish a schematic diagram for the calibration reference;

[0044] Appendix Figure 7 Schematic diagram for calibrating an inertial measurement unit.

[0045] Among them, 1: photoelectric stabilization platform; 2: azimuth axis system; 3: pitch axis system; 4: pitch frame; 5: first axis reference optical reflector; 6: second axis reference optical reflector; 7: marble platform; 8: altimeter; 9: multi-dimensional adjustable reflector; 10: adapter fixture; 11: first photoelectric autocollimator; 12: second photoelectric autocollimator; 13: pentaprism; 14: third photoelectric autocollimator; 15: fourth photoelectric autocollimator; 16: fifth photoelectric autocollimator; 17: large-aperture standard plane mirror; 18: inertial measurement unit. Detailed Implementation

[0046] The present application will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be noted that these embodiments are not intended to limit the present application. Equivalent transformations or substitutions in function, method, or structure made by those skilled in the art based on these embodiments are all within the protection scope of the present application.

[0047] In the description of the embodiments of this application, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the creation of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the creation of this application.

[0048] Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0049] The terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0050] like Figure 3-7 As shown, this embodiment of the invention provides a calibration method for an airborne optoelectronic platform inertial measurement unit, the method comprising:

[0051] S1: The intersection of the azimuth and pitch axes of the airborne platform is detected and adjusted. The center height of the axes is detected using an altimeter. The center height is detected again by fixing one side of the axis and rotating the other side of the axis. The intersection of the two axes is calculated by comparing the results before and after. The direction of axis adjustment is fed back through the detection results to complete the position intersection adjustment.

[0052] S2: Calibrate and test the accuracy of the rotation axis of the azimuth and pitch axis system of the airborne platform. Connect the azimuth and pitch axis system with the multi-dimensional adjustable reflector fixture, collimate the reflector with the photoelectric self-collimating tube, adjust the azimuth and pitch angle of the reflector, and test the rotation accuracy of the axis system.

[0053] S3: Detect and adjust the verticality of the azimuth and pitch axis system of the airborne platform. Once the two rotation axes are calibrated, the verticality of the axis system can be detected. Use two photoelectric autocollimating light tubes and a pentaprism to set up a spatial rectangular coordinate system reference. Use this rectangular coordinate system to detect the verticality of the two axis systems. The verticality adjustment is completed by feeding back the detection results.

[0054] S4: The orthogonality of the optical axis and axis system of the photoelectric platform is detected and adjusted. After the platform's azimuth, pitch axis system intersection and verticality are adjusted, the optical axis adjustment reference is also set up using the photoelectric autocollimating tube and pentaprism. Finally, the 0° field of view incident optical axis of the photoelectric platform and the two rotation axis systems form a pairwise orthogonal spatial reference coordinate system.

[0055] S5: Calibrate the coordinate system deviation of the inertial measurement unit. Since the orthogonal spatial coordinate system has been detected and adjusted, under this reference, the deviation of the inertial measurement unit can be directly detected and calibrated by using the working axis detection reference of the inertial measurement unit itself through the photoelectric autocollimating light tube.

[0056] In some embodiments, such as Figure 3 As shown, S1 includes:

[0057] S1.1: The airborne optoelectronic platform is mounted on the marble platform 7 using the adjustment support fixture, with the two sides of the azimuth axis system 2 placed horizontally;

[0058] S1.2: Use the height measuring instrument 8 to detect the center height of the half-axis rotation axis on both sides of the azimuth axis system 2, and adjust the attitude of the photoelectric stabilization platform 1 so that the center height of the half-axis on both sides is equal, that is, to ensure that the azimuth axis is parallel to the plane of the marble platform 7.

[0059] S1.3: Use the altimeter 8 to detect the center height of the rotation axis of the half-shaft on both sides of the pitch axis system 3. Adjust the height of the half-shaft on both sides of the pitch axis system 3 to be the same by rotating it up and down. Record the vertical height H1 from the center to the plane of the altimeter 8, which is the distance between the solid line in the attached figure and the altimeter 8.

[0060] S1.4: Rotate the pitch axis 3 half-axis counterclockwise by 180° around the azimuth axis 2. Repeat S1.3 to record the vertical height H2 from the center to the plane of the altimeter 8, which is the distance between the dotted line in the attached figure and the altimeter 8.

[0061] S1.5: Calculate the difference between the vertical height H1 from the center to the plane of the altimeter 8 and the adjusted vertical height H2 from the center to the plane of the altimeter 8. This difference H1-H2 is the degree of intersection of the axis positions.

[0062] In some embodiments, S1 further includes comparing the intersection degree of the axis system position with the intersection degree index of the azimuth and pitch axis system position of the airborne optoelectronic platform. If the index requirements are not met, the positions of the half-axis axis systems on both sides of the pitch axis system 3 are adjusted and S1.3-S1.5 are repeated.

[0063] In some embodiments, such as Figure 4 As shown, S2 includes:

[0064] S2.1: Assemble the adapter 10 onto the corresponding half-shafts of the azimuth axis system 2 and the pitch axis system 3, so that the azimuth axis system 2 and the pitch axis system 3 are connected and fastened.

[0065] S2.2: Connect the multidimensional adjustable reflector 9 to the adapter 10, and set the first photoelectric autocollimating tube 11 and the second photoelectric autocollimating tube 12 at the working distance in front of the multidimensional adjustable reflector 9. Perform coarse collimation through the laser collimating image finder of the multidimensional adjustable reflector 9, and adjust the first photoelectric autocollimating tube 11 and the second photoelectric autocollimating tube 12 so that the autocollimated image of the multidimensional adjustable reflector 9 enters the detection field of view.

[0066] S2.3: Fine-tune the first photoelectric autocollimator 11 and the second photoelectric autocollimator 12 from the collimated image to the center position, rotate the axis system at a constant speed, and collect image points in real time. Generally, 30 points are sampled in one revolution. Draw the fitting circle and read the 2ΔR value, which is the angular deflection accuracy.

[0067] S2.4: Adjust the azimuth and elevation angles of the multi-dimensional adjustable reflector 9 to move the image point towards the center. Repeat S2.3 until the angular deflection accuracy is minimized. At this point, the normal to the surface of the multi-dimensional adjustable reflector 9 is the axis of rotation. This completes the calibration and accuracy test of the azimuth and elevation axis system rotation axis. The position of the multi-dimensional adjustable reflector 9 and the adapter fixture 10 after adjustment is finalized.

[0068] In some embodiments, such as Figure 5 As shown, S3 includes: placing a pentaprism 13 at the intersection of the first photoelectric autocollimating tube 11 and the second photoelectric autocollimating tube 12. The incident surface of the pentaprism 13 is collimated with the first photoelectric autocollimating tube 11. After the light beam exits through the pentaprism 13, it is observed through the second photoelectric autocollimating tube 12. At this time, the autocollimation image deviation value is the axis perpendicularity deviation.

[0069] In some embodiments, S3 further includes adjusting the verticality deviation of the azimuth axis system 2 by adjusting the position of the azimuth axis system 2, and re-inspecting it by referring to the intersection detection route of the azimuth and pitch axis system positions. After the deviations of the two axis systems are adjusted, the axis system pins are fitted.

[0070] In some embodiments, after the platform's axis system is calibrated, the orthogonality of the azimuth and pitch axes meets the requirements. The next step is to adjust the platform's optical axis to be pairwise orthogonal to the azimuth and pitch axes, thus forming an orthogonal coordinate system. For example... Figure 6 As shown, S4 includes:

[0071] S4.1: Two reflecting surfaces are installed outside the 18-element inertial measurement unit to replace its working axis, such as... Figure 2 As shown, the two reflecting surfaces include a first axial reference optical reflecting surface 5 and a second axial reference optical reflecting surface 6.

[0072] S4.2: Place a pentaprism 13 in front of the first photoelectric autocollimating tube 11, and adjust the incident surface of the pentaprism 13 to collimate with the first photoelectric autocollimating tube 11 to ensure that the beam emitted from the pentaprism 13 and the incident beam are in the same horizontal plane. Set up a third photoelectric autocollimating tube 14 behind the emitted beam. The third photoelectric autocollimating tube 14 is installed in the envelope area of ​​the second axis reference optical reflection surface 6. Adjust the third photoelectric autocollimating tube 14 to make it orthogonally collimated with the first photoelectric autocollimating tube 11.

[0073] S4.3: Remove the pentaprism 13, set up the fourth photoelectric autocollimating tube 15 in front of the third photoelectric autocollimating tube 14, and adjust the azimuth and pitch angle of the fourth photoelectric autocollimating tube 15 so that it is collimated with the third photoelectric autocollimating tube 14.

[0074] S4.4: A large-aperture standard plane mirror 17 is set up in front of the first photoelectric autocollimating light tube 11. The large-aperture standard plane mirror 17 is collimated with the first photoelectric autocollimating light tube 11. A fifth photoelectric autocollimating light tube 16 is set up in the envelope area of ​​the first axis reference optical reflection surface 5. The fifth photoelectric autocollimating light tube 16 is adjusted to collimate with the large-aperture standard plane mirror 17. Then the orthogonality test and calibration of the optical axis and axis system of the photoelectric platform is completed.

[0075] In some embodiments, such as Figure 7 As shown, S5 includes:

[0076] S5.1: Install the inertial measurement unit 18 at the center of gravity of the photoelectric stabilization platform 1, and place it on the two-dimensional adjustment platform after assembly;

[0077] S5.2: Adjust the azimuth and pitch angle of the two-dimensional platform so that the first photoelectric autocollimating tube 11 and the second photoelectric autocollimating tube 12 are respectively collimated with the multi-dimensional adjustable reflector 9;

[0078] S5.3: Adjust the position of the photoelectric stabilization platform 1 so that its optical axis recognition reference reflective surface is collimated with the fourth photoelectric autocollimating tube 15;

[0079] S5.4: The deviation values ​​of the first axis reference optical reflector 5 and the second axis reference optical reflector 6 of the inertial measurement unit 18 are directly observed through the third photoelectric autocollimator 14 and the fifth photoelectric autocollimator 16, and fed back to the data processing subsystem to complete the deviation calibration of the inertial measurement unit.

[0080] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application. The above description is merely a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of this application, and these improvements and modifications should also be considered within the protection scope of this application.

Claims

1. An airborne optoelectronic platform inertial measurement unit calibration method, the airborne optoelectronic platform comprising an optoelectronic stabilized platform, an azimuth axis system, a pitch axis system and a pitch frame arranged on the optoelectronic stabilized platform, the azimuth axis system and the pitch axis system being respectively composed of two half shafts, each having a rotation axis, the rotation axes having an intersecting and perpendicular relationship in spatial position, characterized in that, The method comprises: S1: detecting and adjusting the intersection of the azimuth-elevation axis system position of the airborne platform; S2: calibrating and detecting the accuracy of the azimuth-elevation axis system rotation axis of the airborne platform; S3: detecting and adjusting the perpendicularity of the azimuth-elevation axis system of the airborne platform; S4: detecting and adjusting the orthogonality of the optical axis of the photoelectric platform and the axis system; S5: calibrating the coordinate system deviation of the inertial measurement unit, The S5 comprises: S5.1: installing the inertial measurement unit at the barycentric position of the photoelectric stable platform, and placing it on the two-dimensional adjustment platform after assembly; S5.2: adjusting the azimuth-elevation angles of the two-dimensional platform to make the first photoelectric autocollimator and the second photoelectric autocollimator collimate with the multi-dimensional adjustable mirror, respectively; S5.3: adjusting the position of the photoelectric stable platform to make the optical axis identification reference reflecting surface collimate with the fourth photoelectric autocollimator; S5.4: directly observing the deviation values of the first axis line reference optical reflecting surface and the second axis line reference optical reflecting surface of the inertial measurement unit through the third photoelectric autocollimator and the fifth photoelectric autocollimator, and feeding back to the data processing subsystem to complete the deviation calibration of the inertial measurement unit.

2. The airborne optoelectronic platform inertial measurement unit calibration method of claim 1, wherein, The S1 comprises: S1.1: erecting the airborne photoelectric platform on the marble platform through the adjustment support tool, and placing the azimuth axis system on both sides of the axis system horizontally; S1.2: detecting the center height of the half-axis rotation axis on both sides of the azimuth axis system using the height measuring instrument, and adjusting the attitude of the photoelectric stable platform to make the azimuth axis parallel to the plane of the marble platform; S1.3: Use the height gauge to detect the center height of the half shaft rotation shaft on both sides of the pitch axis system, adjust the height of the half shaft on both sides of the pitch axis system by up and down rotation, and record the vertical height from the center to the height gauge plane ; S1.4: Rotate the pitch-axis half of the axis system 180° about the azimuth-axis system axis, counterclockwise, and repeat S1.3 to record the vertical height adjustment of the center to the plane of the height finder ; S1.5: Calculate center to tacheometer plane perpendicular height The difference between the center to tacheometer plane adjusted perpendicular height and the difference is the shafting position intersection.

3. The airborne optoelectronic platform inertial measurement unit calibration method of claim 2, wherein, The S1 further comprises comparing the intersection of the axis system position and the intersection index of the azimuth-elevation axis system position of the airborne photoelectric platform, and if the index requirement is not met, adjusting the position of the two half-axes of the elevation axis system and repeating S1.3-S1.

5.

4. The airborne optoelectronic platform inertial measurement unit calibration method of claim 1, wherein, The S2 comprises: S2.1: assembling the adapter tool to the corresponding half-axes on one side of the azimuth axis system and the elevation axis system to connect and fasten the azimuth axis system and the elevation axis system; S2.2: corresponding the multi-dimensional adjustable mirror to the adapter tool, erecting the first photoelectric autocollimator and the second photoelectric autocollimator in front of the multi-dimensional adjustable mirror at a working distance, and adjusting the first photoelectric autocollimator and the second photoelectric autocollimator through the laser collimation finder of the multi-dimensional adjustable mirror to make the self-collimation image of the multi-dimensional adjustable mirror enter the detection field of view; S2.3: fine-adjusting the self-collimation image of the first photoelectric autocollimator and the second photoelectric autocollimator to the center position, rotating the axis system at a constant speed, collecting the image points in real time, drawing a fitting circle, and obtaining the angular deviation rotation accuracy; S2.4: adjusting the azimuth and elevation angles of the multi-dimensional adjustable mirror to make the image points move to the center position, and repeating S2.3 until the angular deviation rotation accuracy is minimum, at which time the face normal line of the multi-dimensional adjustable mirror is the rotation axis, and the calibration and accuracy detection of the azimuth-elevation axis system rotation axis are completed.

5. The airborne optoelectronic platform inertial measurement unit calibration method of claim 1, wherein, The S3 comprises: placing a five-prism at the intersection of the first photoelectric autocollimator and the second photoelectric autocollimator, making the incident surface of the five-prism collimate with the first photoelectric autocollimator, and observing the light beam passing through the exit of the five-prism through the second photoelectric autocollimator, at which time the self-collimation deviation value is the deviation of the axis system perpendicularity.

6. The airborne optoelectronic platform inertial measurement unit calibration method of claim 5, wherein, The S3 further comprises adjusting the position of the azimuth axis system to adjust the deviation of the axis system perpendicularity.

7. The airborne optoelectronic platform inertial measurement unit calibration method of claim 1, wherein, The S4 includes: S4.1: two reflective surfaces are arranged outside the inertial measurement unit instead of its working axis, including a measurement unit first axis reference optical reflective surface and a measurement unit second axis reference optical reflective surface; S4.2: a penta-prism is placed in front of the first photoelectric autocollimator, the incidence surface of the penta-prism is adjusted to be collimated with the first photoelectric autocollimator, the outgoing light beam of the penta-prism is ensured to be in the same horizontal plane with the incidence light beam, a third photoelectric autocollimator is erected behind the outgoing light beam, the third photoelectric autocollimator is installed in the envelope area of the measurement unit second axis reference optical reflective surface, and the third photoelectric autocollimator is adjusted to be orthogonal collimated with the first photoelectric autocollimator; S4.3: the penta-prism is removed, a fourth photoelectric autocollimator is erected in front of the third photoelectric autocollimator, and the azimuth and pitch angles of the fourth photoelectric autocollimator are adjusted to be collimated with the third photoelectric autocollimator; S4.4: a large-diameter standard plane mirror is erected in front of the first photoelectric autocollimator, the large-diameter standard plane mirror is collimated with the first photoelectric autocollimator, a fifth photoelectric autocollimator is erected in the envelope area of the measurement unit first axis reference optical reflective surface, and the fifth photoelectric autocollimator is adjusted to be collimated with the large-diameter standard plane mirror, so that the photoelectric platform optical axis and the shaft system orthogonality detection and adjustment are completed.

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