CN-122016156-A - Photoelectric stabilized platform centroid calibration device and method using air bearing

CN122016156ACN 122016156 ACN122016156 ACN 122016156ACN-122016156-A

Abstract

The invention relates to a photoelectric stabilized platform centroid calibrating device and method using an air bearing, and belongs to the technical field of precision test and measurement. The calibrating device comprises a base, a pair of air bearing symmetrically installed, a butt joint tool connected between air bearing rotors, an inner ring assembly of a photoelectric stabilization platform fixed on the butt joint tool, a photoelectric code disc and a gyroscope, wherein during testing, the free swinging of the inner ring assembly around a pitching axis or an azimuth axis is realized by adjusting the connection mode of the butt joint tool and the air bearing. Based on potential energy conversion relation, the invention calculates the vertical distance from the mass center to the rotating shaft by using a least square method fitting by measuring the balance position of free swing of the inner ring assembly and the maximum angular velocity released from different initial angles and utilizing a plurality of groups of angle-angular velocity data, and finally determines the three-dimensional mass center offset. The invention effectively solves the problem of overlong measuring period on the air bearing by the traditional periodic method, and realizes the high-precision and rapid calibration of the mass center of the inner ring assembly.

Inventors

Dang Zijie
XU QINGQING
XIE HONGWEI
DONG DIAN
MENG LIZHUANG
WANG KAIDI
WU YUJING
LEI FEILIN

Assignees

西安应用光学研究所

Dates

Publication Date: 20260512
Application Date: 20260210

Claims (10)

1. The utility model provides an use air bearing's optoelectronic stabilization platform barycenter calibrating device, its characterized in that includes base (1), install a pair of air bearing (2) on base (1) symmetry, a pair of be connected with butt joint frock (3) between the rotor of air bearing (2), fixedly mounted has optoelectronic stabilization platform inner ring subassembly (4) on butt joint frock (3), through adjusting butt joint frock (3) and air bearing (2) connected mode, make optoelectronic stabilization platform inner ring subassembly (4) can freely swing around pitch axis or azimuth axis; the photoelectric encoder (5) is used for detecting the swinging angle of the butt joint tool (3), and the gyroscope (6) is arranged on the photoelectric stabilized platform inner ring assembly (4) and used for detecting the angular speed of the photoelectric stabilized platform inner ring assembly; The system further comprises a data acquisition module (7) and a data processing module (8), wherein the signal output ends of the photoelectric encoder (5) and the gyroscope (6) are connected to the data acquisition module (7), the data acquisition module (7) is in communication connection with the data processing module (8), and the data processing module (8) is used for executing calculation of mass center offset based on angle data detected by the photoelectric encoder (5) and angular speed data detected by the gyroscope (6).
2. The photoelectric stabilized platform centroid calibrating device using the air bearing according to claim 1, wherein the photoelectric coded disc (5) is installed at the joint of the butt joint tool (3) and the air bearing (2).
3. The photoelectric stabilization platform centroid calibrating device using an air bearing according to claim 1, wherein the gyroscope (6) is a fiber optic gyroscope or a laser gyroscope.
4. The photoelectric stabilization platform centroid calibrating device using an air bearing according to claim 1, wherein the data acquisition module (7) is a data acquisition board.
5. A method of calibrating the centroid of an optoelectronic stabilization platform using the device of any one of claims 1 to 4, comprising the steps of: step1, measuring centroid offset component about first rotation axis Step 1.1, connecting the inner ring component (4) of the photoelectric stabilization platform with an air bearing (2) through a butt joint tool (3) so that the inner ring component (4) of the photoelectric stabilization platform swings freely around a first rotating shaft; Step 1.2, enabling the inner ring assembly (4) of the photoelectric stabilized platform to swing freely around a first rotating shaft under the action of unbalanced moment, measuring the swing angle of the inner ring assembly through the photoelectric coded disc (5), and determining the balance position according to the swing angle; Step 1.3, releasing the photoelectric stabilized platform inner ring assembly (4) after deflecting a preset angle from a balance position, and measuring the maximum angular velocity of the photoelectric stabilized platform inner ring assembly in the free swinging process through the gyroscope (6); step 1.4, changing the preset angle, repeating the step 1.3 for a plurality of times, and obtaining a plurality of groups of measurement data of different preset angles and corresponding maximum angular speeds; step 1.5, based on potential energy conversion relation, utilizing the plurality of groups of measurement data obtained in the step 1.4, and adopting a least square method to fit and calculate the vertical distance from the mass center of the inner ring component (4) of the photoelectric stabilization platform to the first rotating shaft; Step 1.6, calculating an offset component of the centroid in a plane perpendicular to the first rotation axis according to the vertical distance calculated in step 1.5 and the equilibrium position angle determined in step 1.2; step 2, measuring centroid offset component around the second rotation axis Changing the connection mode of the butt joint tool (3) and the air bearing (2) to enable the photoelectric stabilization platform inner ring assembly (4) to swing freely around the second rotating shaft; Repeatedly performing steps 1.2 to 1.6, and calculating an offset component of the centroid in a plane perpendicular to the second rotation axis; Step 3, centroid calibration And (3) determining the barycenter position of the inner ring assembly (4) of the photoelectric stabilized platform in a three-dimensional space based on the offset components calculated in the step (1) and the step (2) for barycenter calibration.
6. The method for calibrating the center of mass of the photoelectric stabilized platform according to claim 5, wherein in step 1.2, the equilibrium position is determined by measuring an angle difference between a peak value angle and a valley value angle of the inner ring assembly (4) of the photoelectric stabilized platform during free swinging through the photoelectric encoder (5), and one half of the angle difference is the equilibrium position angle.
7. The method for calibrating a centroid of a stabilized photoelectric platform according to claim 5, wherein in step 1.5, the specific expression of the potential energy conversion relationship is: wherein J is the rotational inertia of the photoelectric stabilized platform inner ring assembly (4) and the butt joint tool (3) which are integrally wound around a first rotation axis, omega m is the maximum angular velocity, m is the integral mass of the photoelectric stabilized platform inner ring assembly (4) and the butt joint tool (3), g is the gravity acceleration, R is the vertical distance from the mass center to the first rotation axis, and alpha is a preset angle.
8. The method for calibrating the mass center of the optoelectronic stabilized platform according to claim 7, wherein the specific process of calculating the vertical distance R by least square fitting is as follows: Transforming the specific expression of the potential energy conversion relation into a linear equation: Wherein, the , Fitting function ; Based on the sets of data obtained in step 1.4 And And obtaining the value of the fitting coefficient k by least square fitting, namely the vertical distance R.
9. The method according to claim 5, wherein the first rotation axis is a pitch axis, and the offset of the centroid in the roll axis direction is in step 1.6 And the offset of the azimuth axis direction Calculated by the following formula: Wherein, the As the vertical distance of the centroid to the pitch axis, Is the equilibrium position angle of oscillation about the pitch axis.
10. The method according to claim 5, wherein the second rotation axis is an azimuth axis, and in step 2, the centroid is offset in the pitch axis direction Calculated by the following formula: Wherein, the As the perpendicular distance of the centroid to the azimuth axis, Is the equilibrium position angle of oscillation about the azimuth axis.

Description

Photoelectric stabilized platform centroid calibration device and method using air bearing Technical Field The invention belongs to the technical field of precision test and measurement, and particularly relates to a photoelectric stabilized platform centroid calibrating device and method using an air bearing. Background At present, an airborne photoelectric stabilized platform generally adopts a process balancing scheme to adjust the mass center position of an inner ring assembly in the assembly process so as to ensure the stability and the pointing precision of the airborne photoelectric stabilized platform in the operation process. The traditional balancing method is mainly based on a three-point weighing method, namely, projection coordinates of the barycenter of the measured piece in a fulcrum plane are calculated by measuring unbalanced moments of three fulcrum positions, and although the method is suitable for loads with larger mass, the measurement precision of the barycenter in the radial direction of precision equipment such as an inner ring component of a photoelectric stable platform is often insufficient, and the strict requirement of the high-precision stable platform on barycenter calibration is difficult to meet. In order to improve measurement accuracy, a periodic compound pendulum method is introduced into centroid measurement, and the method can effectively measure unbalanced moment of an inner ring assembly of the photoelectric stabilized platform in all directions. However, the measurement accuracy of the conventional compound pendulum method is limited to a great extent by the friction moment of the support bearing, and in order to overcome this limitation, an air bearing is used as a support member, and its negligible low friction characteristic can significantly improve the measurement accuracy. However, the improvement brings new problems that the whole measuring process usually takes a long time and has very low efficiency due to very long swinging period when the traditional compound pendulum periodic method is adopted for measurement in a low friction environment. In the prior art, the air bearing is mainly used for large triaxial air bearing platforms such as satellite simulators, and the mass center balancing method mainly comprises a compound pendulum periodic method and a flywheel moment control method. For example, the invention patent with the application number 201510655822.8, named as a three-axis air bearing table centroid balancing method and device, adopts a mode of combining pre-leveling based on a swinging period and fine leveling based on flywheel wheel control rotating speed. Although the method can realize certain-precision leveling, the method not only depends on a special gesture control mechanism, but also involves multiple measurement and calculation in a staged leveling process, so that the calculation period is longer, and quick high-precision calculation of the centroid position is difficult to realize. The invention patent with the application number 201610131236.8 is similar to a dual-motor automatic balancing method of a triaxial satellite simulator, firstly, an air bearing table kinematic model is established to estimate interference moment, the distance that a mass block in an actuating mechanism needs to move is determined, then the swinging period of the air bearing table is calculated by a vector of a simulator mass center containing the mass block of the stepping motor in a table top coordinate system of the air bearing table, the interference moment is estimated by the swinging period, the mass center offset is determined, and finally, the stepping motor or the ultrasonic motor is driven by a comparison result of mass center offset precision and 0.01 mm. In order to achieve high-precision balancing, the method relies on the mutual matching of two motors, the steps are complicated, the calculation period is long due to repeated iteration and model operation, and the requirement of fast and high-precision centroid deviation calculation cannot be met. In addition, the invention patent with the application number 202110156207.8, named as a method and a system for balancing the mass center of the triaxial air bearing table, carries out flywheel wheel control by respectively putting the triaxial air bearing table in a horizontal state and a bias state, and carries out balancing in the horizontal direction and the vertical direction according to the gesture measured by the gesture measuring instrument. However, the method needs very high gesture measurement precision, increases high-precision data acquisition and processing time under the scene of limited measurement resources such as a small-sized photoelectric platform, and is difficult to finish high-precision centroid deviation calculation in a short time. In summary, the air bearing centroid calibration method in the prior art generally has the problems of long measurement period, complicated steps