Photoelectric stabilized platform centroid calibration device and method applying air bearing

Abstract

The invention relates to a photoelectric stabilized platform centroid calibration device and method applying an air bearing, and belongs to the technical field of precision test and measurement. The calibration device comprises a base, a pair of symmetrically installed air bearings, a butt joint tool connected between rotors of the air bearings, a photoelectric stabilized platform inner ring assembly fixed to the butt joint tool, a photoelectric coded disc and a gyroscope. During testing, free swinging of the inner ring assembly around the pitch axis or the azimuth axis is realized by adjusting the connection mode of the butt joint tool and the air bearing. Based on the potential energy conversion relation, the balance position of free swing of the inner ring assembly and the maximum angular velocity after release from different initial angles are measured, the vertical distance from the mass center to the rotating shaft is calculated through least square fitting by means of multiple sets of angle-angular velocity data, and finally the three-dimensional mass center offset is determined. According to the invention, the problem that the measurement period of a traditional period method on the air bearing is too long is effectively solved, and high-precision rapid calibration of the mass center of the inner ring assembly is realized.

Description

Technical Field

[0001] This invention belongs to the field of precision testing and measurement technology, specifically relating to a centroid calibration device and method for an optoelectronic stabilization platform using an air bearing. Background Technology

[0002] Currently, airborne optoelectronic stabilization platforms commonly employ process balancing schemes during assembly to adjust the center of mass position of their inner ring components, ensuring stability and pointing accuracy during operation. Traditional balancing methods are primarily based on the three-point weighing method, which calculates the projected coordinates of the center of mass of the measured component in the fulcrum plane by measuring the unbalanced torque at three support points. While this method is suitable for large-mass loads, for precision equipment like the inner ring components of optoelectronic stabilization platforms, the radial accuracy of the center of mass measurement is often insufficient, making it difficult to meet the stringent requirements of high-precision stabilization platforms for center of mass calibration.

[0003] To improve measurement accuracy, the periodic pendulum method has been introduced into center-of-mass measurement. This method can effectively measure the unbalanced torque of the inner ring components of a photoelectric stabilization platform in various directions. However, the measurement accuracy of the traditional pendulum method is largely limited by the frictional torque of the support bearing. To overcome this limitation, air bearings are used as support elements, and their negligible low friction characteristics can significantly improve measurement accuracy. But this improvement also brings new problems: in low-friction environments, when using the traditional periodic pendulum method for measurement, the entire measurement process often takes several hours due to the very long oscillation period, resulting in very low efficiency.

[0004] In existing technologies, air bearings are mainly used in large three-axis air-bearing platforms such as satellite simulators. Their center-of-gravity balancing methods primarily include the compound pendulum period method and the flywheel torque control method. For example, the invention patent application number 201510655822.8, entitled "Method and Device for Balancing the Center of Gravity of a Three-Axis Air-Bearing Platform," combines pre-balancing based on the oscillation period with fine-tuning based on the flywheel's controlled rotational speed. While this method can achieve a certain level of balancing accuracy, it not only relies on a dedicated attitude control mechanism but also involves multiple measurements and calculations in a phased balancing process, resulting in a long calculation cycle and making it difficult to achieve rapid and high-precision calculation of the center-of-gravity position.

[0005] Similarly, patent application number 201610131236.8, entitled "Automatic Balancing Method for a Three-Axis Satellite Simulator Using Two Motors," first establishes a kinematic model of the air-bearing platform to estimate the disturbance torque; determines the distance the mass block in the actuator needs to move; then calculates the oscillation period of the air-bearing platform using the vector of the simulator's center of mass (including the stepper motor mass block) in the coordinate system of the air-bearing platform surface; estimates the disturbance torque and determines the center of mass offset using the oscillation period; finally, drives the stepper motor or ultrasonic motor based on the comparison result of the center of mass offset accuracy with 0.01 mm. To achieve high-precision balancing, this method relies on the cooperation of two motors, making the steps relatively cumbersome. Multiple iterations and model calculations result in a long calculation cycle, failing to meet the requirements for fast and high-precision center of mass deviation calculation.

[0006] Furthermore, the invention patent with application number 202110156207.8, entitled "Method and System for Balancing the Center of Gravity of a Three-Axis Air-Float Platform," involves controlling the flywheel of the three-axis air-float platform in both horizontal and offset states, and then balancing it horizontally and vertically based on the attitude measured by an attitude measuring instrument. However, this method requires very high attitude measurement accuracy, which increases the time required for high-precision data acquisition and processing in scenarios with limited measurement resources, such as small optoelectronic platforms, and also makes it difficult to complete high-precision center of gravity deviation calculations in a short time.

[0007] In summary, existing methods for calibrating the centroid of air bearings generally suffer from long measurement cycles, cumbersome procedures, and high dependence on auxiliary equipment, making them unsuitable for the rapid and high-precision centroid calibration requirements of photoelectric stabilization platforms.

[0008] In view of this, the present invention is hereby proposed. Summary of the Invention

[0009] The purpose of this invention is to overcome the shortcomings of the prior art and provide a centroid calibration device and method for an optoelectronic stabilization platform using air bearings. This invention is mainly used to solve the problems of excessively long measurement cycles and complex operation procedures caused by the use of air bearings to reduce friction in existing centroid measurement methods, as well as the insufficient accuracy of the traditional three-point weighing method for measuring the radial centroid of the inner ring component of the optoelectronic stabilization platform.

[0010] The objective of this invention is achieved through the following technical solution:

[0011] On one hand, the present invention provides a centroid calibration device for an optoelectronic stabilization platform using air bearings, including a base, on which a pair of air bearings are symmetrically mounted, and a docking fixture is connected between the rotors of the pair of air bearings. An inner ring assembly of the optoelectronic stabilization platform is fixedly mounted on the docking fixture. By adjusting the connection method between the docking fixture and the air bearings, the inner ring assembly of the optoelectronic stabilization platform can swing freely around the pitch axis or azimuth axis.

[0012] It also includes an optical encoder for detecting the swing angle of the docking fixture, and a gyroscope set on the inner ring assembly of the optical-stabilized platform for detecting its angular velocity;

[0013] It also includes a data acquisition module and a data processing module; the signal output terminals of the photoelectric encoder and the gyroscope are both connected to the data acquisition module, the data acquisition module is communicatively connected to the data processing module, and the data processing module performs the calculation of the centroid offset based on the angle data detected by the photoelectric encoder and the angular velocity data detected by the gyroscope.

[0014] Furthermore, the photoelectric encoder is installed at the connection between the docking fixture and the air bearing.

[0015] Furthermore, the gyroscope is a fiber optic gyroscope or a laser gyroscope.

[0016] Furthermore, the data acquisition module is a data acquisition board.

[0017] On the other hand, the present invention also provides a method for calibrating the centroid of a photoelectric stabilization platform, the calibration method using the above-mentioned apparatus, comprising the following steps:

[0018] Step 1: Measure the centroid offset component around the first rotation axis.

[0019] Step 1.1: Connect the inner ring assembly of the photoelectric stabilization platform to the air bearing through a docking fixture, so that the inner ring assembly of the photoelectric stabilization platform can swing freely around the first rotation axis;

[0020] Step 1.2: Allow the inner ring assembly of the photoelectric stabilization platform to swing freely around the first rotation axis under the action of unbalanced torque, measure its swing angle through the photoelectric code disk, and determine the equilibrium position based on the swing angle;

[0021] Step 1.3: After deflecting the inner ring component of the photoelectric stabilization platform from the equilibrium position by a predetermined angle, release it and measure its maximum angular velocity during the free swing process using the gyroscope;

[0022] Step 1.4: Change the predetermined angle and repeat step 1.3 multiple times to obtain multiple sets of measurement data of the predetermined angle and the corresponding maximum angular velocity;

[0023] Step 1.5: Based on the potential energy conversion relationship, using the multiple sets of measurement data obtained in Step 1.4, the least squares method is used to fit and calculate the vertical distance from the centroid of the inner ring component of the photoelectric stabilization platform to the first rotation axis.

[0024] Step 1.6: Based on the vertical distance calculated in Step 1.5 and the equilibrium position angle determined in Step 1.2, calculate the offset component of the center of mass in the plane perpendicular to the first rotation axis.

[0025] Step 2: Measure the centroid offset component around the second rotation axis.

[0026] By changing the connection method between the docking fixture and the air bearing, the inner ring assembly of the photoelectric stabilization platform can swing freely around the second rotation axis.

[0027] Repeat steps 1.2 to 1.6 to calculate the offset component of the centroid in the plane perpendicular to the second rotation axis;

[0028] Step 3, Centroid Calibration

[0029] Based on the offset components calculated in steps 1 and 2, the centroid position of the inner ring component of the photoelectric stabilization platform in three-dimensional space is determined for centroid calibration.

[0030] Further, in step 1.2, the equilibrium position is determined as follows: the angle difference between the peak angle and the valley angle of the inner ring component of the photoelectric stabilization platform when it swings freely is measured by the photoelectric encoder disk, and half of the angle difference is the equilibrium position angle.

[0031] Furthermore, in step 1.5, the specific expression for the potential energy conversion relationship is as follows:

[0032]

[0033] Where J is the moment of inertia of the inner ring assembly of the photoelectric stabilization platform and the docking fixture as a whole about the first rotation axis, and ω m denoted as the maximum angular velocity, m as the overall mass of the inner ring assembly of the photoelectric stabilization platform and the docking fixture, g as the gravitational acceleration, R as the vertical distance from the center of mass to the first rotation axis, and α as the predetermined angle.

[0034] Furthermore, the specific process of calculating the vertical distance R using the least squares fitting method is as follows:

[0035] The specific expression for the potential energy conversion relationship is transformed into a linear equation:

[0036]

[0037] in, , Fitting function ;

[0038] Based on the multiple sets of data obtained in step 1.4, the value of the fitting coefficient k is obtained by fitting using the least squares method, which is the vertical distance R.

[0039] Furthermore, the first rotation axis is the pitch axis, and in step 1.6, the offset of the center of mass in the roll axis direction... Offset in azimuth axis direction Calculated using the following formula:

[0040]

[0041] in, The vertical distance from the center of mass to the pitch axis. The equilibrium position angle is the oscillation around the pitch axis.

[0042] Furthermore, the second rotation axis is the azimuth axis, and in step 2, the offset of the center of mass in the pitch axis direction... Calculated using the following formula:

[0043]

[0044] in, The perpendicular distance from the center of mass to the azimuth axis. The equilibrium position angle is the oscillation around the azimuth axis.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] 1. This invention uses an air bearing as a rotating support component, eliminating the need to consider the influence of bearing clearance and friction torque on the oscillation. This provides a near-ideal low-friction environment for the centroid calibration of the inner ring component of the photoelectric stabilization platform, eliminating interference factors and thus improving measurement accuracy.

[0047] 2. This invention abandons the traditional time-consuming periodic method. First, it calculates and determines the equilibrium position angle by measuring the difference between the peak and trough angles during the measurement process. Then, it uses the energy balance method to obtain the vertical distance from the center of mass to the rotation axis. Finally, it calculates the center of mass offset to determine the center of mass position. Based on the angle data detected by the photoelectric encoder and the angular velocity data detected by the gyroscope during the above execution process, this method eliminates the need to wait for multiple complete oscillation cycles during testing. The single measurement time is extremely short. Combined with least squares fitting, it can quickly complete the acquisition and calculation of multiple sets of data, significantly shortening the testing time and thus improving testing efficiency.

[0048] 3. The calibration method of this invention does not rely on complex attitude control or trimming actuators such as flywheels and stepper motors. Furthermore, angular velocity detection can directly utilize the gyroscope inherent in the inner ring component of the photoelectric stabilization platform, eliminating the need for additional high-cost sensors and significantly reducing system complexity and calibration testing costs. Simultaneously, the adjustable docking fixture allows for rapid switching between pitch and azimuth axis measurement configurations, effectively solving the problem of insufficient accuracy in radial centroid measurement of the inner ring component of the photoelectric stabilization platform using traditional methods, thus achieving rapid and high-precision calibration. Attached Figure Description

[0049] The accompanying drawings are incorporated in and form part of this specification, and together with the description serve to explain the principles of the invention.

[0050] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0051] Figure 1 This is a schematic diagram of the overall structure of the photoelectric stabilization platform centroid calibration device using air bearings (without the inner ring assembly of the photoelectric stabilization platform installed).

[0052] Figure 2 This is a schematic diagram of the connection between the inner ring assembly of the photoelectric stabilization platform and the docking fixture and the air bearing of the present invention; (a) the inner ring assembly of the photoelectric stabilization platform is parallel to the axis of the air bearing with the pitch axis (oy axis), and (b) the inner ring assembly of the photoelectric stabilization platform is parallel to the axis of the air bearing with the azimuth axis (oz axis).

[0053] Figure 3 This is a schematic diagram of the electrical connection of the centroid calibration device for the inner ring component of the photoelectric stabilization platform using air bearings according to the present invention.

[0054] Figure 4 This is a schematic diagram of the equilibrium position of the inner ring component of the photoelectric stabilization platform of the present invention under free swing around the pitch axis or azimuth axis;

[0055] Figure 5 This is a flowchart of the centroid calibration method for the inner ring component of the photoelectric stabilization platform of the present invention.

[0056] in:

[0057] 1 is the base; 2 is the air bearing; 3 is the docking fixture; 4 is the inner ring assembly of the photoelectric stabilization platform; 5 is the photoelectric encoder; 6 is the gyroscope; 7 is the data acquisition module; 8 is the data processing module; 9 is the power supply. Detailed Implementation

[0058] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses consistent with some aspects of the invention as detailed in the appended claims.

[0059] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0060] Please see Figures 1-3 The present invention provides a centroid calibration device for a photoelectric stabilization platform using an air bearing, which mainly consists of a base 1, an air bearing 2, a docking fixture 3, an inner ring assembly of the photoelectric stabilization platform 4, a photoelectric encoder 5, and a gyroscope 6. The base 1 has two spaced and relatively vertically arranged support plates, each with an air bearing 2 mounted on it. The two air bearings 2 are symmetrically arranged and coaxial. The docking fixture 3 has a quadrilateral frame structure, with its two ends connected to the rotors of the two air bearings 2 respectively. The inner ring assembly 4 of the photoelectric stabilization platform is fixedly installed inside the docking fixture 3, and the two are fixed together as a whole by a locking mechanism to ensure that no relative displacement occurs during the calibration process. The specific form of the locking mechanism of this invention is not limited, and it can be a common mechanical fixing method such as pin, clamp or screw clamping. The photoelectric encoder 5 serves as an angle detection device and is installed at the connection between the docking fixture 3 and any air bearing 2 to accurately detect the swing angle of the docking fixture 3 around the axis of the air bearing. The gyroscope 6 serves as an angular velocity detection device and is installed on the inner ring assembly 4 of the photoelectric stabilization platform to directly detect its angular velocity around the pitch axis or azimuth axis.

[0061] Preferably, the photoelectric encoder 5 used in this invention is a high-precision photoelectric encoder; the gyroscope 6 used is a high-precision gyroscope, such as a fiber optic gyroscope or a laser gyroscope.

[0062] It should be noted that the four-sided frame structure of the docking fixture 3 of the present invention has a standardized installation position preset at the outer center of each side, forming a cross structure. This setting allows the docking fixture 3 to be connected to the air bearing 2 in both the vertical and horizontal directions. In other words, by adjusting the relative connection position between the docking fixture 3 and the air bearing 2, the pitch axis or azimuth axis of the inner ring component 4 of the photoelectric stabilization platform can be kept parallel to the axis of the air bearing 2, thereby achieving free swinging around different axes and providing a structural basis for measuring the offset component of the center of mass in three-dimensional space.

[0063] The calibration device of this invention also includes a data acquisition module 7, a data processing module 8, and a power supply 9. The power supply 9 is electrically connected to each electrical device (including but not limited to the photoelectric encoder 5, gyroscope 6, and data acquisition module 7), providing power to each device. The signal output terminals of the photoelectric encoder 5 and the gyroscope 6 are respectively connected to the data acquisition module 7. The data acquisition module 7 establishes a communication connection with the data processing module 8. The data processing module 8 calculates the centroid offset based on the angle data acquired by the photoelectric encoder 5 and the angular velocity data acquired by the gyroscope 6.

[0064] Preferably, the data acquisition module 7 can be a data acquisition board, and the data processing module 8 is dedicated analysis software running on a computer platform.

[0065] In addition, such as Figure 5 As shown, the present invention also provides a method for calibrating the centroid of a photoelectric stabilization platform. This calibration method uses the above-mentioned apparatus and specifically includes the following steps:

[0066] Step 1: Measure the centroid offset component around the pitch axis

[0067] Step 1.1: Fix the inner ring assembly 4 of the photoelectric stabilization platform into the docking fixture 3 using a locking mechanism, forming a single unit with no relative movement. Then connect it to the air bearing 2 through the docking fixture 3. Figure 2 As shown in (a), its center of rotation is defined as the origin. , The axis coincides with the azimuth axis. The axis coincides with the pitch axis. The axis coincides with the roll axis, at which point the inner ring component 4 of the photoelectric stabilization platform rotates around the pitch axis ( (Axis) free to swing;

[0068] Step 1.2: After connecting the sensor electrical equipment, allow the inner ring assembly 4 of the photoelectric stabilization platform to swing freely around the pitch axis under the action of unbalanced torque, i.e., from the horizontal attitude ( With the axis kept horizontal, the device is released to allow free swinging. The difference between the peak and valley angles of the inner ring assembly 4 of the photoelectric stabilization platform during the free swinging process around the pitch axis is measured via the photoelectric encoder 5. Since the platform rotation angle is 0° when the inner ring component 4 of the photoelectric stabilization platform is in a horizontal position, the equilibrium position angle is... ,like Figure 4 As shown;

[0069] Step 1.3: After deflecting the inner ring component 4 of the photoelectric stabilization platform from its equilibrium position by a predetermined angle α, release it and measure its maximum angular velocity during the free swing process using the gyroscope 6. ;

[0070] Step 1.4: Change the predetermined angle α. Repeat step 1.3 to perform multiple tests (for example, set a predetermined angle α of 10°, 20°, 30°, etc.) to obtain multiple sets of measurement data of different predetermined angles and corresponding maximum angular velocities;

[0071] Step 1.5: Based on the potential energy conversion relationship, using the multiple sets of measurement data obtained in Step 1.4, the vertical distance from the center of mass of the inner ring component 4 of the photoelectric stabilization platform to the pitch axis is calculated using the least squares method. ;

[0072] Specifically, the specific expression for the potential energy conversion relationship is as follows:

[0073]

[0074] in, The moment of inertia of the inner ring component 4 and the docking fixture 3 of the photoelectric stabilization platform rotating about the pitch axis can be obtained using structural simulation software. The maximum angular velocity about the pitch axis during the oscillation process. Let g be the overall mass of the inner ring component 4 of the photoelectric stabilization platform and the docking fixture 3, and g be the acceleration due to gravity. The vertical distance from the center of mass to the pitch axis is α, and α is a predetermined angle.

[0075] The relationship between kinetic energy and potential energy was measured multiple times as follows:

[0076]

[0077] Least squares method for fitting vertical distance calculation The specific process is as follows:

[0078] Transform the specific expression of the potential energy conversion relationship into a linear equation:

[0079]

[0080] in, , Fitting function ;

[0081] Based on the multiple sets of data obtained in step 1.4, the fitting coefficient k is obtained by fitting using the least squares method, which is the vertical distance from the centroid to the pitch axis. .

[0082] Step 1.6: Calculate the vertical distance based on Step 1.5. Angle relative to the equilibrium position determined in step 1.2 The offset component of the centroid in the plane perpendicular to the pitch axis is calculated using the following trigonometric function.

[0083]

[0084] in, The vertical distance from the center of mass to the pitch axis. The equilibrium position angle of the oscillation about the pitch axis. This represents the offset of the center of mass in the roll axis direction. This represents the offset of the centroid along the azimuth axis.

[0085] Step 2: Measure the centroid offset component around the azimuth axis

[0086] Step 2.1: Change the connection method between the docking fixture 3 and the air bearing 2, that is, rotate the docking fixture 3 together with the inner ring assembly 4 of the photoelectric stabilization platform 90° clockwise and then connect it with the air bearing 2, as shown below. Figure 2 As shown in (b), at this time, the inner ring component 4 of the photoelectric stabilization platform can rotate around the azimuth axis ( (Axis) free to swing;

[0087] Step 2.2: After connecting the sensor electrical equipment, allow the inner ring assembly 4 of the photoelectric stabilization platform to swing freely around the pitch axis under the action of unbalanced torque, i.e., from the horizontal attitude ( With the axis kept horizontal, the device is released to allow free swinging. The difference between the peak and valley angles of the inner ring assembly 4 of the photoelectric stabilization platform during its free swing around the azimuth axis is measured using the photoelectric encoder 5. Since the platform rotation angle is 0° when the inner ring component 4 of the photoelectric stabilization platform is in a horizontal position, the equilibrium position angle is... ,like Figure 4 As shown;

[0088] Step 2.3: Deflect the inner ring component 4 of the photoelectric stabilization platform from its equilibrium position by a predetermined angle. After release, its maximum angular velocity during free swing is measured using gyroscope 6. ;

[0089] Step 2.4: Change the predetermined angle , Repeat step 2.3 multiple times to obtain multiple sets of measurement data of different predetermined angles and corresponding maximum angular velocities;

[0090] Step 2.5: Based on the potential energy conversion relationship, using the multiple sets of measurement data obtained in Step 2.4, the vertical distance from the center of mass of the inner ring component 4 of the photoelectric stabilization platform to the azimuth axis is calculated using the least squares method. ;

[0091] Specifically, the specific expression for the potential energy conversion relationship is as follows:

[0092]

[0093] in, The moment of inertia of the inner ring component 4 and the docking fixture 3 of the photoelectric stabilization platform rotating about the azimuth axis can be obtained using structural simulation software. The maximum angular velocity about the pitch axis during the oscillation process. Let g be the overall mass of the inner ring component 4 of the photoelectric stabilization platform and the docking fixture 3, and g be the acceleration due to gravity. The perpendicular distance from the center of mass to the azimuth axis. For the predetermined angle;

[0094] The relationship between kinetic energy and potential energy was measured multiple times as follows:

[0095]

[0096] Least squares method for fitting vertical distance calculation The specific process is as follows:

[0097] Transform the specific expression of the potential energy conversion relationship into a linear equation:

[0098]

[0099] in, , Fitting function ;

[0100] Based on the multiple sets of data obtained in step 2.4, the fitting coefficient k is obtained by fitting using the least squares method, which is the vertical distance from the centroid to the azimuth axis. .

[0101] Step 2.6: Calculate the vertical distance based on Step 2.5. Angle relative to the equilibrium position determined in step 2.2 The offset component of the centroid in the plane perpendicular to the azimuth axis is calculated using the lower trigonometric function.

[0102]

[0103] in, The perpendicular distance from the center of mass to the azimuth axis. The equilibrium position angle of the oscillation about the azimuth axis. This represents the offset of the center of mass along the pitch axis.

[0104] Step 3, Centroid Calibration

[0105] The offset of the centroid in the roll axis direction calculated based on steps 1 and 2. The offset of the centroid in the azimuth axis direction The offset of the center of mass in the pitch axis direction The position of the centroid of the inner ring component 4 of the photoelectric stabilization platform in three-dimensional space is determined for subsequent centroid calibration.

[0106] It should be noted that when measuring the centroid offset component of the inner ring component 4 of the photoelectric stabilization platform, the order of measuring around the pitch axis and azimuth axis is not limited. That is, the centroid offset component around the azimuth axis can be measured first. In other words, there is no order requirement for steps 1 and 2 as a whole.

[0107] The above description is merely a specific embodiment of the present invention, intended to enable those skilled in the art to understand and implement the present invention. Various modifications to these embodiments without creative effort will be readily apparent to those skilled in the art; the basic principles defined herein can be applied to other embodiments without departing from the spirit and scope of the present invention.

[0108] It should be understood that this invention is not limited to the specific content described above, and various equivalent modifications or substitutions can be made without departing from its scope of protection. The scope of protection of this invention is defined only by the appended claims.

Claims

1. A centroid calibration device for a photoelectric stabilization platform using air bearings, characterized in that, Includes a base (1), on which a pair of air bearings (2) are symmetrically mounted, and a docking fixture (3) is connected between the rotors of the pair of air bearings (2). An inner ring assembly (4) of the photoelectric stabilization platform is fixedly mounted on the docking fixture (3). By adjusting the connection method between the docking fixture (3) and the air bearings (2), the inner ring assembly (4) of the photoelectric stabilization platform can swing freely around the pitch axis or azimuth axis. It also includes an optoelectronic encoder (5) for detecting the swing angle of the docking fixture (3), and a gyroscope (6) set on the inner ring assembly (4) of the optoelectronic stabilization platform for detecting its angular velocity. It also includes a data acquisition module (7) and a data processing module (8); the signal output terminals of the photoelectric encoder (5) and the gyroscope (6) are both connected to the data acquisition module (7), the data acquisition module (7) is communicatively connected to the data processing module (8), and the data processing module (8) performs the calculation of the centroid offset based on the angle data detected by the photoelectric encoder (5) and the angular velocity data detected by the gyroscope (6).

2. The centroid calibration device for a photoelectric stabilization platform using an air bearing as described in claim 1, characterized in that, The photoelectric encoder (5) is installed at the connection between the docking fixture (3) and the air bearing (2).

3. The centroid calibration device for a photoelectric stabilization platform using an air bearing as described in claim 1, characterized in that, The gyroscope (6) is a fiber optic gyroscope or a laser gyroscope.

4. The centroid calibration device for a photoelectric stabilization platform using an air bearing as described in claim 1, characterized in that, The data acquisition module (7) is a data acquisition board.

5. A method for calibrating the centroid of a photoelectric stabilization platform using the device described in any one of claims 1 to 4, characterized in that, Includes the following steps: Step 1: Measure the centroid offset component around the first rotation axis. Step 1.1: Connect the inner ring assembly (4) of the photoelectric stabilization platform to the air bearing (2) through the docking fixture (3) so that the inner ring assembly (4) of the photoelectric stabilization platform can swing freely around the first rotation axis; Step 1.2: Allow the inner ring assembly (4) of the photoelectric stabilization platform to swing freely around the first rotation axis under the action of unbalanced torque, measure its swing angle through the photoelectric code disk (5), and determine the balance position according to the swing angle; Step 1.3: After deflecting the inner ring component (4) of the photoelectric stabilization platform from the equilibrium position by a predetermined angle, release it and measure its maximum angular velocity during the free swing process using the gyroscope (6); Step 1.4: Change the predetermined angle and repeat step 1.3 multiple times to obtain multiple sets of measurement data of the predetermined angle and the corresponding maximum angular velocity; Step 1.5: Based on the potential energy conversion relationship, using the multiple sets of measurement data obtained in Step 1.4, the least squares method is used to fit and calculate the vertical distance from the center of mass of the inner ring component (4) of the photoelectric stabilization platform to the first rotation axis. Step 1.6: Based on the vertical distance calculated in Step 1.5 and the equilibrium position angle determined in Step 1.2, calculate the offset component of the center of mass in the plane perpendicular to the first rotation axis. Step 2: Measure the centroid offset component around the second rotation axis. Change the connection method between the docking fixture (3) and the air bearing (2) so that the inner ring assembly (4) of the photoelectric stabilization platform can swing freely around the second rotation axis; Repeat steps 1.2 to 1.6 to calculate the offset component of the centroid in the plane perpendicular to the second rotation axis; Step 3, Centroid Calibration Based on the offset components calculated in steps 1 and 2, the centroid position of the inner ring component (4) of the photoelectric stabilization platform in three-dimensional space is determined for centroid calibration.

6. The centroid calibration method for an optoelectronic stabilization platform according to claim 5, characterized in that, In step 1.2, the equilibrium position is determined as follows: the angle difference between the peak angle and the valley angle of the inner ring component (4) of the photoelectric stabilization platform when it swings freely is measured by the photoelectric encoder (5), and half of the angle difference is the equilibrium position angle.

7. The method for calibrating the centroid of a photoelectric stabilization platform according to claim 5, characterized in that, In step 1.5, the specific expression for the potential energy conversion relationship is as follows: Where J is the moment of inertia of the inner ring assembly (4) of the photoelectric stabilization platform and the docking fixture (3) as a whole about the first rotation axis, and ω m α is the maximum angular velocity, m is the overall mass of the inner ring component (4) of the photoelectric stabilization platform and the docking fixture (3), g is the gravitational acceleration, R is the vertical distance from the center of mass to the first rotation axis, and α is the predetermined angle.

8. The method for calibrating the centroid of a photoelectric stabilization platform according to claim 7, characterized in that, The specific process of calculating the vertical distance R using the least squares method is as follows: The specific expression for the potential energy conversion relationship is transformed into a linear equation: in, , Fitting function ; Based on the multiple sets of data obtained in step 1.4 and The value of the fitting coefficient k is obtained by fitting using the least squares method, which is the vertical distance R.

9. The centroid calibration method for an optoelectronic stabilization platform according to claim 5, characterized in that, The first rotation axis is the pitch axis. In step 1.6, the offset of the center of mass in the roll axis direction... Offset in azimuth axis direction Calculated using the following formula: in, The vertical distance from the center of mass to the pitch axis. The equilibrium position angle is the oscillation around the pitch axis.

10. The method for calibrating the centroid of a photoelectric stabilization platform according to claim 5, characterized in that, The second rotation axis is the azimuth axis. In step 2, the offset of the center of mass in the pitch axis direction... Calculated using the following formula: in, The perpendicular distance from the center of mass to the azimuth axis. The equilibrium position angle is the oscillation around the azimuth axis.

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