Null-point calibration method for roll-type optoelectronic payload and inertial navigation of high-speed aircraft

Abstract

This invention relates to a zero-position calibration method for roll-mounted optoelectronic payloads and inertial navigation systems of high-speed aircraft, belonging to the technical field of roll-mounted optoelectronic payloads and inertial navigation systems for high-speed aircraft. This method achieves precise zeroing of roll-mounted optoelectronic payloads and inertial navigation systems. Using simple equipment such as collimators, the roll and pitch of the roll-mounted optoelectronic payload and inertial navigation system are zeroed in a laboratory environment, with a zeroing error not exceeding 0.02°. This aims to improve the target positioning accuracy of the roll-mounted optoelectronic payload and reduce calibration errors.

Description

Technical Field

[0001] This invention belongs to the field of high-speed aircraft roll-type optoelectronic payload and inertial navigation application technology, specifically relating to a zero-position calibration method for high-speed aircraft roll-type optoelectronic payload and inertial navigation. Background Technology

[0002] Modern warfare demands that air-to-air missiles possess strong maneuverability, first-strike capability, and all-aspect attack capability. This necessitates a large off-axis angle and field of view for the seeker, as well as small size and light weight. The stabilization platform of the roll-elevation seeker employs a universal support structure with a roll outer frame and an elevation inner frame. Its field of view can cover the entire forward hemisphere, providing the necessary conditions for the missile to achieve a large off-axis angle launch. Therefore, it has become an ideal choice for the new generation of air-to-air loitering missiles.

[0003] The high-speed aircraft roll-pitch electro-optical payload target positioning method refers to the use of electro-optical equipment installed on the high-speed aircraft to calculate target point navigation information based on the target's roll, pitch angles, and distance measurements taken by the electro-optical payload, as well as the current geographical coordinates and altitude transmitted by inertial navigation. However, due to errors between the inertial navigation coordinate system and the electro-optical turret coordinate system, and the difficulty in mechanically ensuring accurate zero-position calibration, error propagation is amplified during target positioning. Traditional high-speed aircraft or carrier aircraft target positioning is dependent on the aircraft and high-speed aircraft, requiring calibration, data communication, and synchronization with the high-speed aircraft / carrier. This firstly hinders the expansion of the application range of the electro-optical platform; secondly, it has site requirements and is complex, requiring the installation of target scopes, leveling the high-speed aircraft or aircraft, observation, etc., a process that typically takes 5-8 hours. Finally, this process is costly, including instrument design and production costs, and generates significant calibration errors. Summary of the Invention

[0004] (a) Technical problems to be solved

[0005] The technical problem to be solved by this invention is: how to provide a zero-position calibration method for roll-type optoelectronic payloads and inertial navigation of high-speed aircraft to address the problem of inaccurate zero-point calibration between airborne or loitering type optoelectronic payloads and inertial navigation.

[0006] (II) Technical Solution

[0007] To address the aforementioned technical problems, this invention provides a zero-position calibration method for roll-type optoelectronic payloads and inertial navigation in high-speed aircraft, comprising the following steps:

[0008] S1: Install mechanical fixtures for placing the square tube front mirror.

[0009] Install a mechanical fixture on a horizontal turntable. This mechanical fixture has horizontal and vertical end faces. Place a level on the mechanical fixture and level both sides. Then, press the horizontal and vertical surfaces of the square tube front mirror tightly against the horizontal and vertical end faces of the mechanical fixture to ensure that the optical axis of the square tube front mirror is parallel to the ground.

[0010] S2: Set point target

[0011] A plumb line is suspended in front of the focal length of the collimator. A point target that can be moved up and down is placed on the plumb line to ensure that the point target is within the field of view of the front mirror of the square tube. The horizontal turntable is rotated so that the reticle cross of the front mirror of the square tube and the image of the point target on the plumb line in the collimator are completely superimposed.

[0012] S3: The high-speed aircraft's roll-type electro-optical payload and inertial navigation system are fixedly installed together;

[0013] S4: Calibrate the roll zero of the photoelectric payload and inertial navigation.

[0014] Power on the photoelectric payload and inertial navigation system. Lock the roll angle of the photoelectric payload to approximately -90° and the pitch angle to 0°. Move the mechanical fixture until the optical axis crosshair in the image observed by the photoelectric payload is nearly aligned with the image of the point target set in step S2 within the collimator. Fine-tune the roll and pitch angles of the photoelectric payload until the optical axis crosshair in the image is completely aligned with the image of the point target within the collimator. Record the roll angle of the photoelectric payload and the roll angle of the inertial navigation system at this point. The sum of the two angles is θ. Then, -90°-θ is the zero-position error of the photoelectric payload and inertial navigation system in the roll axis. Add -90°-θ to the output roll angle value of the photoelectric payload to complete the zero-position correction of the roll axis of the photoelectric payload and inertial navigation system. Power off the photoelectric payload and inertial navigation system.

[0015] S5: Calibrate the pitch null position of the photoelectric payload and inertial navigation.

[0016] Power on the photoelectric payload and inertial navigation system. Lock the roll angle of the photoelectric payload to approximately 0° and the pitch angle to 90°. Move the mechanical fixture until the optical axis crosshair in the image observed by the photoelectric payload is nearly aligned with the image of the point target set in step S2 within the collimator. Fine-tune the pitch angle of the photoelectric payload, and fine-tune the roll and pitch angles of the photoelectric payload until the optical axis crosshair in the image is completely aligned with the image of the point target within the collimator. Record the pitch angle of the photoelectric payload and the pitch angle of the inertial navigation system at this time. The sum of the two angles is φ. 90°-φ is the zero-position error of the photoelectric payload and inertial navigation system in the pitch axis. Add 90°-φ to the pitch angle value output by the photoelectric payload to complete the zero-position correction in the pitch axis. Power off the photoelectric payload and inertial navigation system.

[0017] Preferably, in step S3, the high-speed aircraft roll-type optoelectronic payload and inertial navigation are fixedly mounted on a mounting fixture.

[0018] Preferably, the two mounting surfaces of the mounting fixture have shape tolerance and position tolerance requirements, respectively.

[0019] Preferably, when the high-speed aircraft roll-type optoelectronic payload and inertial navigation are fixedly mounted on a mounting fixture, the mounting screws need to be coated with thread-locking adhesive.

[0020] Preferably, in steps S4 and S5, the vertical downward field of view is defined as the zero position of the photoelectric load.

[0021] The present invention also provides an optoelectronic payload and inertial navigation obtained by calibrating the zero position using the method described above.

[0022] The present invention also provides a method for conducting flight test verification of the aforementioned optoelectronic payload and inertial navigation.

[0023] Preferably, two target points are selected. First, the position information of the two target points is measured by GPS. Then, an octocopter UAV is used to carry the photoelectric payload after zero-position calibration and inertial navigation to conduct target positioning experiments to verify the position information of the two target points. The position information measured by GPS is compared with the position information obtained through the target positioning experiment.

[0024] Preferably, the location information includes longitude, latitude, and altitude information.

[0025] The present invention also provides a high-speed aircraft based on the calibration method described above.

[0026] (III) Beneficial Effects

[0027] The method for zero-position calibration of high-speed aircraft roll-type optoelectronics and navigation provided by the above technical solution has the following beneficial effects:

[0028] 1. The zero-position calibration method for high-speed aircraft roll-type optoelectronic payload and inertial navigation of the present invention expands the use of target positioning function and geographic guidance function under the inherent advantages of the large off-axis angle and field of view of the high-speed aircraft roll-type optoelectronic payload. It no longer requires calibration, data communication and synchronization with the high-speed aircraft or aircraft, thus expanding the application scope of optoelectronic platform.

[0029] 2. The zero-position calibration method for high-speed aircraft roll-type optoelectronic payload and inertial navigation of the present invention has simple and clear steps, and the entire zero-position calibration process can be completed in an indoor laboratory environment, solving the problems of high cost and high cost of instruments and production in traditional calibration methods;

[0030] 3. The zero-position calibration method for the high-speed aircraft roll-type optoelectronic payload and inertial navigation of the present invention has a small zero-position calibration error. After calibration, multiple static target positioning verifications of the latitude and longitude of multiple target points are performed in the field. Under the condition that the inertial navigation is accurately aligned and does not diverge while running in the vehicle, the target positioning error is controlled within 10m. Attached Figure Description

[0031] Figure 1 This is a flowchart of the method of the present invention;

[0032] Figure 2 This is a simulation diagram of the calibration zero position of the present invention;

[0033] Figure 3 This is a diagram showing the field positioning results achieved using the method of this invention. Detailed Implementation

[0034] To make the objectives, contents, and advantages of the present invention clearer, the specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples.

[0035] This invention addresses the problem of inaccurate zero-point calibration between airborne or loitering electro-optical payloads and inertial navigation systems by providing a zero-point calibration method for roll-type electro-optical payloads and inertial navigation systems in high-speed aircraft. This embodiment details the calibration method for the electro-optical payload and inertial navigation system mounted on mechanical fixtures, and analyzes the target positioning data from the calibrated electro-optical payload in the field to demonstrate the accuracy of the calibration method.

[0036] Reference Figures 1 to 3 As shown, the zero-position calibration method for roll-and-tilt photoelectric payload and inertial navigation in this embodiment includes the following steps:

[0037] S1: Install mechanical fixtures for placing the square tube front mirror.

[0038] Install a mechanical fixture on a horizontal turntable. This fixture has horizontal and vertical end faces. Place a level on the fixture and level both sides. Then, ensure the horizontal and vertical surfaces of the square tube front mirror are firmly attached to the horizontal and vertical end faces of the fixture, respectively, guaranteeing that the optical axis of the square tube front mirror is parallel to the ground. Figure 2 S1 is shown in the dashed box;

[0039] S2: Set point target

[0040] A plumb line is suspended in front of the focal length of the collimator. A point target that can be moved up and down is placed on the plumb line, ensuring that the point target is within the field of view of the front lens of the square tube. The horizontal turntable is rotated until the reticle crosshairs of the front lens of the square tube completely coincide with the image of the point target on the plumb line in the collimator. See [link to diagram]. Figure 2 As shown in the dashed box in S2;

[0041] S3: Install inertial navigation and optoelectronic payloads

[0042] The high-speed aircraft's roll-and-pitch electro-optical payload and inertial navigation system are fixedly mounted on a mounting fixture, forming a single unit. The two mounting surfaces of this fixture have specific form and position tolerance requirements, and the mounting screws must be coated with 242 thread-locking adhesive to prevent loosening after calibration. See [link / details]. Figure 2 S3 is shown in the dashed box;

[0043] S4: Calibrate the roll zero of the photoelectric payload and inertial navigation.

[0044] Power on the photoelectric payload and inertial navigation system. Lock the roll angle of the photoelectric payload to approximately -90° and the pitch angle to approximately 0° (the zero position of the photoelectric payload is when the field of view is vertically downward). Move the mechanical fixture so that the crosshair of the optical axis in the image observed by the photoelectric payload is nearly coincident with the image of the point target set in step S2 in the collimator. Fine-tune the roll and pitch angles of the photoelectric payload so that the crosshair of the optical axis in the image is completely coincident with the image of the point target in the collimator. Record the roll angle of the photoelectric payload and the roll angle of the inertial navigation system at this time. The sum of the two angles is θ. Then, -90°-θ is the zero position error of the photoelectric payload and inertial navigation system in the roll axis. The photoelectric payload should add -90°-θ to its original output angle value to complete the zero position correction of the roll axis of the photoelectric payload and inertial navigation system. Power off the photoelectric payload and inertial navigation system.

[0045] S5: Calibrate the pitch null position of the photoelectric payload and inertial navigation.

[0046] Power on the photoelectric payload and inertial navigation system. Lock the roll angle of the photoelectric payload to approximately 0° and the pitch angle to approximately 90° (the zero position of the photoelectric payload is when the field of view is vertically downward). Move the mechanical fixture until the optical axis crosshair in the image observed by the photoelectric payload is nearly coincident with the image of the point target set in step S2 in the collimator. Fine-tune the pitch angle of the photoelectric payload, and fine-tune the roll and pitch angles of the photoelectric payload until the optical axis crosshair in the image is completely coincident with the image of the point target in the collimator. Record the pitch angle of the photoelectric payload and the pitch angle of the inertial navigation system at this time. The sum of the two angles is φ. Then 90°-φ is the zero position error of the photoelectric payload and inertial navigation system in the pitch axis. The photoelectric payload should add 90°-φ to its original output angle value to complete the zero position correction in the pitch axis. Power off the photoelectric payload and inertial navigation system.

[0047] S6: Experimental Verification

[0048] The photoelectric payload and inertial navigation were tested and verified by a flight experiment after the zero-position calibration. Two target points were selected: point A5 and Lanyuege. The accurate position information of the two points was measured in advance using GPS inertial navigation. Finally, an octocopter UAV was used to carry the photoelectric payload and inertial navigation after the zero-position calibration to verify the target positioning experiment. The position information of the two points is shown in Table 1.

[0049] Table 1 Comparison of Target Location Results at Two Points

[0050]

[0051] The comparison results show that the longitude, latitude and altitude errors of the target points A5 and Lanyuege are all within the CEP10 range, indicating a significant improvement in photoelectric target positioning indicators and a clear calibration effect.

[0052] As can be seen, this invention achieves precise zeroing for roll-mounted photoelectric loads and inertial navigation systems. By using simple equipment such as collimators to zero the roll and pitch of roll-mounted loads and inertial navigation systems in a laboratory environment, the zeroing error does not exceed 0.02°, which can improve the target positioning accuracy of roll-mounted photoelectric loads and reduce calibration errors.

[0053] The above description is only a preferred embodiment of the present invention. 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 the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A zero-position calibration method for roll-type optoelectronic payloads and inertial navigation of high-speed aircraft, characterized in that, Includes the following steps: S1: Install mechanical fixtures for placing the square tube front mirror. Install a mechanical fixture on a horizontal turntable. This mechanical fixture has horizontal and vertical end faces. Place a level on the mechanical fixture and level both sides. Then, press the horizontal and vertical surfaces of the square tube front mirror tightly against the horizontal and vertical end faces of the mechanical fixture to ensure that the optical axis of the square tube front mirror is parallel to the ground. S2: Set point target A plumb line is suspended in front of the focal length of the collimator. A point target that can be moved up and down is placed on the plumb line to ensure that the point target is within the field of view of the front mirror of the square tube. The horizontal turntable is rotated so that the reticle cross of the front mirror of the square tube and the image of the point target on the plumb line in the collimator are completely superimposed. S3: The high-speed aircraft's roll-type electro-optical payload and inertial navigation system are fixedly installed together; S4: Calibrate the roll zero of the photoelectric payload and inertial navigation. Power on the photoelectric payload and inertial navigation system, lock the roll angle of the photoelectric payload to -90° and the pitch angle to 0°, move the mechanical fixture so that the optical axis crosshair in the image observed by the photoelectric payload is nearly coincident with the image of the point target set in step S2 in the collimator, fine-tune the roll and pitch angles of the photoelectric payload so that the optical axis crosshair in the image is completely coincident with the image of the point target in the collimator, record the roll angle of the photoelectric payload and the roll angle of the inertial navigation system at this time, the sum of the two angles is θ, then -90°-θ is the zero-position error of the photoelectric payload and inertial navigation system in the roll axis; add -90°-θ to the output roll angle value of the photoelectric payload to complete the zero-position correction of the roll axis of the photoelectric payload and inertial navigation system, and power off the photoelectric payload and inertial navigation system. S5: Calibrate the pitch null position of the photoelectric payload and inertial navigation. Power on the photoelectric payload and inertial navigation system, lock the roll angle of the photoelectric payload to 0° and the pitch angle to 90°, move the mechanical fixture so that the optical axis crosshair in the image observed by the photoelectric payload is nearly coincident with the image of the point target set in step S2 in the collimator, fine-tune the pitch angle of the photoelectric payload, and fine-tune the roll and pitch angles of the photoelectric payload so that the optical axis crosshair in the image is completely coincident with the image of the point target in the collimator, record the pitch angle of the photoelectric payload and the pitch angle of the inertial navigation system at this time, and the sum of the two angles is φ. Then 90°-φ is the zero-position error of the photoelectric payload and inertial navigation system in the pitch axis; add 90°-φ to the pitch angle value output by the photoelectric payload to complete the zero-position correction of the pitch axis, and power off the photoelectric payload and inertial navigation system.

2. The method as described in claim 1, characterized in that, In step S3, the high-speed aircraft's roll-type electro-optical payload and inertial navigation system are fixedly mounted on an installation fixture.

3. The method as described in claim 2, characterized in that, The two mounting surfaces of the mounting fixture have shape tolerance and position tolerance requirements, respectively.

4. The method as described in claim 2, characterized in that, When mounting a high-speed aircraft's roll-up electro-optical payload and inertial navigation system onto a single mounting fixture, the mounting screws must be coated with thread-locking adhesive.

5. The method as described in claim 1, characterized in that, In steps S4 and S5, the vertical downward field of view is defined as the zero position of the photoelectric load.

6. An optoelectronic payload and inertial navigation system obtained by calibrating the zero position using the method described in any one of claims 1 to 5.

7. A method for conducting flight test verification of the optoelectronic payload and inertial navigation system according to claim 6, characterized in that, Two target points were selected. First, the position information of the two target points was measured by GPS. Then, an octocopter UAV was used to carry the photoelectric payload after zero-position calibration and inertial navigation to conduct a target positioning experiment to verify the position information of the two target points. The position information measured by GPS was compared with the position information obtained through the target positioning experiment.

8. The method as described in claim 7, characterized in that, The location information includes longitude, latitude, and altitude.

9. A high-speed aircraft obtained based on the method of any one of claims 1 to 5.

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