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CN-121978987-A - Magnetic suspension test system for satellite attitude verification and control method thereof

CN121978987ACN 121978987 ACN121978987 ACN 121978987ACN-121978987-A

Abstract

The invention discloses a magnetic suspension testing system for satellite attitude verification and a control method thereof, and relates to the technical field of equipment testing. The connecting rod passes through the through hole and is axially limited and protected by the first limiting part and the second limiting part, the bottom end of the connecting rod is connected with a satellite to be verified, the top end of the connecting rod is fixedly provided with a permanent magnet and is coaxially aligned with the electromagnet, and controllable magnetic attraction force is generated after the connecting rod is electrified so as to counteract the gravity of the subsystem, so that a non-contact suspension support is established. The laser displacement sensor is aligned with the second limiting part to measure distance information, judges the suspension state according to the distance change and feeds back and adjusts electromagnet current to realize suspension height closed-loop control. The system has compact structure and clear control logic, remarkably reduces the influence of mechanical friction and assembly errors, and is suitable for repeatable ground verification of micro-nano satellite attitude control in a vacuum environment.

Inventors

  • GUO YUNTAO
  • GAO TIANYU
  • WU ZHIWEN

Assignees

  • 北京理工大学

Dates

Publication Date
20260505
Application Date
20260203

Claims (10)

  1. 1. A magnetic levitation test system for satellite attitude verification, comprising: The frame body is provided with a plurality of frame bodies, The first electromagnet is fixedly connected with the top end of the frame body; the connecting body is fixedly connected with the first electromagnet, a through hole is formed in the bottom end of the connecting body, and the axis of the through hole is correspondingly arranged with the magnetic shaft of the first electromagnet; the connecting rod comprises a first limiting part and a second limiting part, the connecting rod penetrates through the through hole of the connecting body, the first limiting part and the second limiting part are respectively positioned at two ends of the through hole, and the bottom end of the connecting rod is connected with a satellite to be verified; the permanent magnet is fixedly connected to the top end of the connecting rod, and a magnetic shaft of the permanent magnet is arranged corresponding to the axis of the connecting rod; The laser displacement sensor is fixedly connected with the frame body and used for measuring distance information of the second limiting part.
  2. 2. The magnetic levitation testing system for satellite pose verification of claim 1, further comprising: The horizontal magnetic field compensation coil group is connected with the frame body and comprises at least two groups of horizontal magnetic field compensation coils, and the center line of each horizontal magnetic field compensation coil is positioned between the top ends of the first electromagnet and the permanent magnets.
  3. 3. The magnetic levitation testing system for satellite pose verification of claim 1, further comprising: the damping disc is connected to the connecting rod near the bottom end; The second electromagnet and the third electromagnet are connected to the frame body, and the second electromagnet and the third electromagnet are symmetrically arranged relative to the axis of the damping disc.
  4. 4. The magnetic levitation testing system for satellite pose verification of claim 1, further comprising: The high-speed camera is fixed on the frame body.
  5. 5. The magnetic levitation test system for satellite attitude verification according to claim 1, wherein the measuring component of the laser displacement sensor is disposed corresponding to the second limiting portion, and the second limiting portion is in a shape of a truncated cone.
  6. 6. A control method for the magnetic levitation test system for satellite attitude verification according to any one of claims 1 to 5, comprising: after the satellite to be verified completes testing preparation work, the first electromagnet is controlled to be electrified, and the distance information between the first electromagnet and the second limiting part, which is measured by the laser displacement sensor, is obtained; And controlling the energizing current information of the first electromagnet based on the distance information to control the attractive force between the first electromagnet and the permanent magnet, so that the distance information between the first electromagnet and the permanent magnet is within a preset distance range.
  7. 7. The control method according to claim 6, characterized in that the controlling of the energization current information of the first electromagnet based on the distance information includes: Acquiring the distance information and comparing the distance information with preset distance information corresponding to a preset target suspension distance to obtain a distance deviation value; constructing a suspension state error signal based on the distance deviation amount, and generating a corresponding current adjustment amount according to the error signal; And superposing the current adjustment quantity on the basis of the initial electrifying current of the first electromagnet to serve as electrifying current information of the first electromagnet so as to dynamically adjust the magnetic field intensity generated by the first electromagnet.
  8. 8. The control method according to claim 7, wherein in the case where the second limit portion is in a truncated cone shape, the current adjustment amount is calculated based on the following formula: wherein k is the current sampling time; The total output of the controller, namely the PWM value loaded on the electromagnet; the feedforward control quantity is used for balancing the gravity of the suspension; The current position error is the difference value between the actual measured value and the set value; The measured value is the measured value of the laser displacement sensor at the current moment; the measured value of the laser displacement sensor at the previous moment; The speed value is the speed value after the first-order low-pass filtering treatment at the current moment; The velocity value is the velocity value after the first-order low-pass filtering treatment at the previous moment; is a velocity filter coefficient; the proportional, integral and differential gain coefficients, respectively.
  9. 9. The control method according to claim 7, wherein in the case where the magnetic levitation test system for satellite attitude verification further includes a horizontal magnetic field compensation coil group, the control method further includes: After the first electromagnet and the permanent magnet form a magnetic suspension state, the horizontal magnetic field compensation coil group is controlled to be electrified so as to generate a compensation magnetic field in the horizontal direction, wherein the intensity of the compensation magnetic field generated in the horizontal direction is determined by the following formula: The central magnetic induction intensity generated by the coil; Is vacuum magnetic permeability; a single coil turn; The current is the magnitude of the current; is the radius of the coil; Is the distance between the two coils; Acquiring attitude oscillation characteristic information of the satellite to be verified in a suspension state, wherein the attitude oscillation characteristic information comprises oscillation period information; Adjusting the current proportion and the current amplitude of each compensation coil in the horizontal magnetic field compensation coil group based on the attitude oscillation characteristic information so as to change the direction and the intensity of the compensation magnetic field; and iteratively adjusting the direction and the intensity of the compensation magnetic field to enable the attitude oscillation characteristics of the satellite to be verified to meet the preset stability condition so as to reduce the influence of the magnetic field non-uniformity of the magnetic suspension system in the horizontal direction on the attitude verification.
  10. 10. The control method according to claim 7, wherein in the case where the magnetic levitation test system for satellite attitude verification further includes a damping plate, a second electromagnet, and a third electromagnet, the method further comprises: After finishing a posture verification test, acquiring rotation state information of the satellite to be verified in a magnetic suspension state; when the rotation state of the satellite to be verified is judged to be less than a preset reset condition, the second electromagnet and the third electromagnet are controlled to be electrified, so that a magnetic field is generated at the damping disc; And attenuating the rotation states of the connecting rod and the satellite to be verified by utilizing an electromagnetic damping effect generated by the motion of the damping disk in the magnetic field, wherein the calculation formula of the electromagnetic damping effect is as follows: Wherein F is a magnetic force, The remanence is the property of the material itself; Is the relative magnetic permeability of the material; the length of the air gap is l, the length of the magnet is l; Vacuum magnetic permeability is adopted, and A is the area of the magnet; When the rotation state of the satellite to be verified is judged to meet the preset reset condition, the second electromagnet and the third electromagnet are controlled to be powered off, so that electromagnetic damping action on the damping disc is relieved, and the magnetic suspension test system is enabled to enter the next posture verification test state.

Description

Magnetic suspension test system for satellite attitude verification and control method thereof Technical Field The specification relates to the technical field of equipment testing, in particular to a magnetic suspension testing system for satellite attitude verification and a control method thereof. Background In recent years, micro-nano satellites have been developed into important spacecraft types for bearing complex tasks such as remote sensing, communication, navigation and the like from early teaching and verification platforms due to the advantages of low development cost, short period, flexible deployment and the like. Along with the continuous improvement of the task complexity and precision requirements, the requirements of the micro-nano satellite on the gesture control precision and stability are obviously improved, and the gesture control performance is directly related to the task execution effect. However, compared with a large spacecraft, the micro-nano satellite has the characteristics of small mass and low moment of inertia, and the micro-moment generated by any moving part on the satellite can generate a remarkable dynamic coupling effect with the satellite body, so that the attitude disturbance amplification and even the system instability are caused. Therefore, the ground attitude control verification of high fidelity is carried out before the transmission, and the method has important significance for finding potential coupling problems, verifying the performance of a control algorithm and an executing mechanism. The ideal ground verification environment should reproduce as much as possible the free dynamics of the satellite in orbit under nearly frictionless, microgravity conditions, but under ground conditions any supporting or constraining structure inevitably introduces friction, damping or additional moments, thereby affecting the authenticity of the verification result. The existing satellite attitude control ground verification means mainly comprise digital simulation and physical simulation tests. Digital simulation relies on mathematical models and computer simulation, and it is difficult to fully reflect the real physical coupling process. The air bearing table and the magnetic bearing table system which are commonly used in physical simulation can reduce friction influence to a certain extent. The air bearing table depends on compressed gas to form an air film, so that the air bearing table is difficult to work in a vacuum environment, and the system is complex and has high cost. Although the magnetic levitation table can operate under the vacuum condition, the problems of residual mechanical contact, high requirements on machining and assembling precision, high cost, insufficient universality and repeatability and the like commonly exist in the existing scheme, and part of systems are difficult to support a tested satellite to realize closed-loop attitude control verification through an executing mechanism of the system. Therefore, there is a need for a microsatellite ground pose verification system that has a relatively simplified structure, no mechanical friction or low mechanical friction, can operate in a vacuum environment, and has good versatility and repeatability, so as to achieve high-fidelity ground verification of the microsatellite pose dynamics and control process. Disclosure of Invention In the summary, a series of concepts in a simplified form are introduced, which will be further described in detail in the detailed description. The summary of the application is not intended to define the key features and essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. In a first aspect, the present invention proposes a magnetic levitation test system for satellite attitude verification, comprising: The frame body is provided with a plurality of frame bodies, The first electromagnet is fixedly connected with the top end of the frame body; The connecting body is fixedly connected with the first electromagnet, a through hole is formed in the bottom end of the connecting body, and the axis of the through hole is correspondingly arranged with the magnetic shaft of the first electromagnet; The connecting rod comprises a first limiting part and a second limiting part, the connecting rod penetrates through the through hole of the connecting body, the first limiting part and the second limiting part are respectively positioned at two ends of the through hole, and the bottom end of the connecting rod is connected with a satellite to be verified; A permanent magnet fixedly connected to the top end of the connecting rod, wherein a magnetic axis of the permanent magnet is arranged corresponding to the axis of the connecting rod; And the laser displacement sensor is fixedly connected with the frame body and is used for measuring the distance information between the laser displacement sensor a