A high-precision angle tracking mechanism control system based on magnetic bearing

Abstract

A kind of high-precision angle tracking mechanism control system based on magnetic bearing, adopts the composite rotating platform mode of two-dimensional mechanical turntable+magnetic bearing tracking mechanism combination, both can give full play to the characteristics of two-dimensional mechanical turntable large rotation range, fast rotation, and can utilize the characteristics of magnetic bearing tracking mechanism accurate angle control, realize the purpose of target wide range fast capture and accurate tracking control, corresponding angle control precision can reach or exceed ±0.1 angular second order of magnitude, can be used for space high-precision pointing tracking and control, and be applicable to the industrial equipment, aerospace, optical instrument and precision measurement system needing accurate pointing control, high-frequency vibration isolation and high stability.

Description

Technical Field

[0001] This invention relates to a high-precision angle tracking mechanism control system based on magnetic bearings, belonging to the field of precision motion control technology. Background Technology

[0002] With the development of tracking mechanism angle control precision technology, many optical payloads have increasingly higher requirements for angle control precision. Traditional mechanical bearings (such as ball bearings and sliding bearings) are difficult to meet the application requirements of high-precision pointing, high-speed tracking, and long lifespan due to friction, high-frequency jitter, mechanical wear, lubrication requirements, and lifespan limitations. Magnetic bearing technology achieves non-contact control of the float by the bearing stator through electromagnetic force, with advantages such as no friction, no wear, and long lifespan. Existing magnetic bearings have been widely used in high-speed rotating components, effectively improving the lifespan and reliability of moving parts. A single magnetic bearing, equipped with a precise displacement sensor, can achieve high-precision float displacement control. Based on this characteristic, multiple magnetic bearings can be designed to work collaboratively to achieve overall levitation of the float support gimbal and high-precision pointing control. Existing high-precision pointing and tracking is usually based on encoder angle measurement and bearing rotation. Due to the limitations of encoder angle measurement resolution and bearing control jitter, it is difficult to achieve pointing accuracy better than sub-arcsecond. Therefore, pointing control based on magnetic bearings is the future development direction for high-precision angle control. Summary of the Invention

[0003] The technical problem solved by this invention is: addressing the insufficient pointing control accuracy caused by factors such as the limit of encoder angle measurement resolution and bearing control jitter in the existing technology, a high-precision angle tracking mechanism control system based on magnetic bearings is proposed.

[0004] The present invention solves the above-mentioned technical problem through the following technical solution: A high-precision angle tracking mechanism control system based on magnetic bearings includes a two-dimensional mechanical turntable, a magnetic bearing tracking mechanism, and an information processing and control module, wherein: The magnetic bearing tracking mechanism includes a stator section, a float section, and magnetic bearing assemblies. The stator section is mechanically connected to the inner frame of a two-dimensional mechanical turntable and performs coarse directional control as the turntable rotates. The float section has magnetic bearing assemblies installed at intervals, and the buoyancy control is achieved through the magnetic force between the magnetic bearing assemblies and the stator section. The magnetic bearing tracking mechanism receives buoyancy commands from the information processing and control module and adjusts the position of each magnetic bearing in the magnetic bearing assembly to perform buoyancy control. The two-dimensional mechanical turntable receives control commands from the information processing and control module to perform mechanical pointing control; it adjusts the mechanical pointing with magnetic force according to the start-up and levitation control amplitude of the magnetic bearing tracking mechanism to accurately point to the tracking target; The information processing and control module generates control commands based on the inner frame of the two-dimensional mechanical turntable and the orientation of the tracking target, and sends them to the two-dimensional mechanical turntable to adjust its mechanical orientation. After the mechanical orientation of the two-dimensional turntable is adjusted, the module samples the suspension gap between the float and the magnetic bearing assembly, calculates the control electromagnetic force, and uses the control electromagnetic force to generate a buoyancy start command, which is sent to the magnetic bearing tracking mechanism to adjust the magnetic bearing suspension position of the magnetic bearing assembly relative to the float.

[0005] The omnidirectional rotation range of the two-dimensional mechanical turntable is 360° omnidirectional in the turntable orientation and -90° to 90° in the pitch direction; the magnetic bearing assembly consists of individual magnetic bearings, with four magnetic bearings installed on the float part, evenly distributed in a circumferential pattern at 90° intervals. During the buoyancy control phase, each magnetic bearing generates a magnetic force with the stator part to achieve the angle adjustment of the float part relative to the target being tracked. Each magnetic bearing is provided with two degrees of freedom for control, and the two-dimensional angle control of each magnetic bearing is achieved through the magnetic force.

[0006] Each magnetic bearing in the magnetic bearing assembly is equipped with an eddy current sensor to monitor the change in the suspension gap between the electromagnet stator and the float of each magnetic bearing. The suspension gap is used to reflect the voltage analog quantity reflecting the change in the position of the float part in the X-axis and Z-axis directions of the magnetic bearing coordinate system.

[0007] The information processing and control module generates a buoyancy start command containing control electromagnetic forces (x1, z1, x2, z2, x3, z3, x4, z4) based on the collected suspension gap and sends it to the four magnetic bearings of the magnetic bearing tracking mechanism. The magnetic bearings generate control current and corresponding control electromagnetic forces according to the corresponding control electromagnetic forces, and adjust the suspension position of the magnetic bearing group relative to the float part and the angle towards the tracking target to complete the buoyancy start control closed loop.

[0008] During the buoyancy control process, any three of the four magnetic bearings in the float section can be selected to perform joint actions based on the specific orientation of the tracking target to determine the pose of the float platform. PID control is used to achieve three-point positioning to adjust the pose of the magnetic bearings relative to the float platform. The fourth magnetic bearing is kept at zero position through PD control.

[0009] The translational displacement of the float portion of the magnetic bearing tracking mechanism occurs after the buoyancy control begins. The calculation method for the translational displacement is as follows:

[0010] In the formula, ( i =1,2,3,4) is the first i The displacement of a magnetic bearing in the X direction of its body coordinate axis; ( i =1,2,3,4) is the first i A magnetic bearing on its body coordinate axisZ Displacement in the direction; x This represents the displacement of the magnetic bearing float along its coordinate axis X. y This represents the displacement of the magnetic bearing float along its Y-axis. z This represents the displacement of the magnetic bearing float along its coordinate axis Z. The three-point positioning of the float platform is based on the control parameters ( , , ) to achieve, control parameters ( , , The calculation method for ) is as follows:

[0011]

[0012]

[0013] In the formula, The selected system cutoff angular frequency; For the selected system Damping ratio; These are parameters related to the current stiffness coefficient of magnetic bearings; This is a parameter related to the displacement stiffness coefficient of the magnetic bearing; it is used as a coefficient to adjust the deviation integration capability. When the value is 0, the control mode changes from PID control to PD control.

[0014] After the buoyancy control is initiated, the float section initiates buoyancy and isolates the vibration of the two-dimensional mechanical turntable. By calculating the rotation angle of the float platform, the suspension zero-position correction amount of each magnetic bearing is calculated using the rotation angle of the float platform and the relative installation relationship of each magnetic bearing. Based on the suspension zero-position correction amount, buoyancy control is implemented to change the position of each magnetic bearing relative to the float platform. After the precise pointing control, the magnetic bearing tracking mechanism and the two-dimensional mechanical turntable assembly complete the tracking process of the target.

[0015] The method for calculating the rotation angle of the float platform is as follows:

[0016] In the formula, L Install the span for the two diagonally opposite magnetic bearings. , The pitch angle of the float platform is selected as a reference control value based on the installation relationship between the magnetic bearing position and the measurement coordinate system when the float part moves according to the pitch angle. This is the azimuth angle of the float platform.

[0017] The information processing and control module includes a high-speed measurement and acquisition unit, a high-performance control and processing unit, a position sensor module, a power amplifier module, and a communication interface, wherein: The high-speed measurement and acquisition unit is used to acquire the omnidirectional rotation range of the two-dimensional mechanical turntable, the two-dimensional angle of each magnetic bearing, the suspension gap between the electromagnet stator and the float of each magnetic bearing, the magnetic bearing suspension position of the magnetic bearing group relative to the float part and the angle towards the tracking target, and send it to the high-performance control and processing unit for information processing. The high-performance control processing unit receives the omnidirectional rotation range of the two-dimensional mechanical turntable and the two-dimensional angles of each magnetic bearing from the high-speed measurement and acquisition unit to determine the position and orientation of the two-dimensional mechanical turntable and the magnetic bearing tracking mechanism assembly. It calculates the control electromagnetic force corresponding to the buoyancy start command based on the suspension gap between the electromagnet stator and the float of each magnetic bearing, and uses it to send the buoyancy start command to the magnetic bearing tracking mechanism. The position sensor module collects the magnetic bearing suspension position of the magnetic bearing assembly relative to the float part and the angle towards the tracking target for subsequent precise pointing control; The power amplifier module amplifies and filters the start-up command output by the high-performance control processing unit. The communication interface is used for signal format conversion between modules.

[0018] The displacement variation range of the magnetic bearing is less than 1 mm. The magnetic bearing assembly adopts an integrated custom processing design. The mechanical assembly error of the float part is less than 50 micrometers to ensure the coordinated operation of each magnetic bearing. The accuracy of the eddy current sensor exceeds ±0.1 arcseconds.

[0019] The advantages of this invention compared to the prior art are: (1) The present invention provides a high-precision angle tracking mechanism control system based on magnetic bearings. It uses a composite rotating platform combining a two-dimensional mechanical turntable and a magnetic bearing tracking mechanism. This can take advantage of the large rotation range and high speed of the two-dimensional mechanical turntable, and utilize the precise angle control characteristics of the magnetic bearing tracking mechanism to achieve the purpose of large-range rapid acquisition and precise tracking control of the target. (2) This invention uses a high-precision eddy current sensor, which can achieve position change measurement with micron-level precision. By measuring the displacement of multiple floats, high-precision angle pointing information is obtained. At the same time, by comprehensively utilizing the spacecraft kinematic information and its own angle sensor information, a control method combining PID stable control and angle feedforward compensation is used to achieve pointing control with sub-arcsecond or even higher precision. (3) By designing multiple magnetic bearings to work together, the present invention can achieve overall suspension and high-precision pointing control of the float support gimbal. With the non-contact characteristics of the magnetic bearings, the high-frequency vibration of the installation platform can be isolated, thereby effectively ensuring the stability of the float support gimbal. At the same time, by selecting a suitable eddy current sensor, optimizing the control parameters and the angle tracking strategy with real-time zero-position correction, the magnetic bearing position control accuracy at the micron level can be achieved. The corresponding angle control accuracy can reach or exceed ±0.1 arcseconds, which significantly improves the tracking and pointing accuracy of the effective load and can be applied to precision equipment and tracking and pointing application scenarios with higher precision or stability requirements. Attached Figure Description

[0020] Figure 1 A control system block diagram of the precise angle control tracking mechanism provided by the present invention; Figure 2 The diagram showing the configuration and coordinate relationship of the single-magnetic-bearing electromagnet provided by this invention; Figure 3 The diagram illustrates the configuration and working principle of the magnetic bearing tracking mechanism provided by this invention. Detailed Implementation

[0021] A high-precision angle tracking mechanism control system based on magnetic bearings adopts a composite rotary platform combining a two-dimensional mechanical turntable and a magnetic bearing tracking mechanism. This system can fully utilize the large rotation range and high speed of the two-dimensional mechanical turntable, while also leveraging the precise angle control characteristics of the magnetic bearing tracking mechanism. This enables the system to achieve rapid acquisition and precise tracking control of targets over a wide range. The corresponding angle control accuracy can reach or exceed the ±0.1 arcsecond level. It can be used for high-precision pointing tracking and control in aerospace, and is also suitable for industrial equipment, aerospace, optical instruments, and precision measurement systems that require precise pointing control, high-frequency vibration isolation, and high stability.

[0022] The high-precision angle tracking mechanism control system based on magnetic bearings comprises the following components: The system comprises a two-dimensional mechanical turntable, a magnetic bearing tracking mechanism, and an information processing and control module, wherein: The magnetic bearing tracking mechanism includes a stator section, a float section, and magnetic bearing assemblies. The stator section is mechanically connected to the inner frame of a two-dimensional mechanical turntable and performs coarse directional control as the turntable rotates. The float section has magnetic bearing assemblies installed at intervals, and the buoyancy control is achieved through the magnetic force between the magnetic bearing assemblies and the stator section. The magnetic bearing tracking mechanism receives buoyancy commands from the information processing and control module and adjusts the position of each magnetic bearing in the magnetic bearing assembly to perform buoyancy control. The two-dimensional mechanical turntable receives control commands from the information processing and control module to perform mechanical pointing control; it adjusts the mechanical pointing with magnetic force according to the start-up and levitation control amplitude of the magnetic bearing tracking mechanism to accurately point to the tracking target; The information processing and control module generates control commands based on the inner frame of the two-dimensional mechanical turntable and the orientation of the tracking target, and sends them to the two-dimensional mechanical turntable to adjust its mechanical orientation. After the mechanical orientation of the two-dimensional turntable is adjusted, the module samples the suspension gap between the float and the magnetic bearing assembly, calculates the control electromagnetic force, and uses the control electromagnetic force to generate a buoyancy start command, which is sent to the magnetic bearing tracking mechanism to adjust the magnetic bearing suspension position of the magnetic bearing assembly relative to the float.

[0023] The omnidirectional rotation range of the two-dimensional mechanical turntable is 360° in the turntable plane and -90° to 90° in the pitch direction. The magnetic bearing assembly consists of individual magnetic bearings. Four magnetic bearings are set on the float part, which are evenly distributed in a circumferential direction at 90° intervals. During the buoyancy control stage, each magnetic bearing generates a magnetic force with the stator part to realize the angle adjustment of the float part relative to the target. Each magnetic bearing is set with two degrees of freedom, and the two-dimensional angle control of each magnetic bearing is achieved through the magnetic force.

[0024] Each magnetic bearing in the magnetic bearing assembly is equipped with an eddy current sensor to monitor the change in the suspension gap between the electromagnet stator and the float of each magnetic bearing. The suspension gap is used to reflect the voltage analog quantity reflecting the change in the position of the float part in the X and Z axes of the magnetic bearing coordinate system.

[0025] The information processing and control module generates a buoyancy start command containing control electromagnetic forces (x1, z1, x2, z2, x3, z3, x4, z4) based on the collected suspension gap and sends it to the four magnetic bearings of the magnetic bearing tracking mechanism. The magnetic bearings generate control current and corresponding control electromagnetic forces according to the corresponding control electromagnetic forces, and adjust the suspension position of the magnetic bearing group relative to the float part and the angle towards the tracking target to complete the buoyancy start control closed loop.

[0026] During the buoyancy control process, any three of the four magnetic bearings in the float section can be selected to perform joint actions based on the specific orientation of the tracking target to determine the pose of the float platform. Three-point positioning is achieved through PID control to adjust the pose of the magnetic bearings relative to the float platform. The fourth magnetic bearing is kept at zero position through PD control.

[0027] The translational displacement of the float section of the magnetic bearing tracking mechanism occurs after the buoyancy control begins. The calculation method for the translational displacement is as follows:

[0028] In the formula, ( i =1,2,3,4) is the first i The displacement of a magnetic bearing in the X direction of its body coordinate axis; ( i =1,2,3,4) is the first iA magnetic bearing on its body coordinate axis Z Displacement in the direction; x This represents the displacement of the magnetic bearing float along its coordinate axis X. y This represents the displacement of the magnetic bearing float along its Y-axis. z This represents the displacement of the magnetic bearing float along its coordinate axis Z. The three-point positioning of the float platform is based on the control parameters ( , , ) to achieve, control parameters ( , , The calculation method for ) is as follows:

[0029]

[0030]

[0031] In the formula, The selected system cutoff angular frequency; For the selected system Damping ratio; These are parameters related to the current stiffness coefficient of magnetic bearings; This is a parameter related to the displacement stiffness coefficient of the magnetic bearing; it is used as a coefficient to adjust the deviation integration capability. When the value is 0, the control mode changes from PID control to PD control.

[0032] After the buoyancy control is initiated, the float section initiates buoyancy and isolates the vibration of the two-dimensional mechanical turntable. By calculating the rotation angle of the float platform, the suspension zero-position correction of each magnetic bearing is calculated using the rotation angle of the float platform and the relative installation relationship of each magnetic bearing. Based on the suspension zero-position correction, buoyancy control is implemented to change the position of each magnetic bearing relative to the float platform. After the precise pointing control, the magnetic bearing tracking mechanism and the two-dimensional mechanical turntable assembly complete the tracking process of the target.

[0033] The method for calculating the rotation angle of the float platform is as follows:

[0034] In the formula, L Install the span for the two diagonally opposite magnetic bearings. , The pitch angle of the float platform is selected as a reference control value based on the installation relationship between the magnetic bearing position and the measurement coordinate system when the float part moves according to the pitch angle. This is the azimuth angle of the float platform.

[0035] The information processing and control module includes a high-speed measurement and acquisition unit, a high-performance control and processing unit, a position sensor module, a power amplifier module, and a communication interface, wherein: The high-speed measurement and acquisition unit is used to acquire the omnidirectional rotation range of the two-dimensional mechanical turntable, the two-dimensional angle of each magnetic bearing, the suspension gap between the electromagnet stator and the float of each magnetic bearing, the magnetic bearing suspension position of the magnetic bearing group relative to the float part and the angle towards the tracking target, and send it to the high-performance control and processing unit for information processing. The high-performance control processing unit receives the omnidirectional rotation range of the two-dimensional mechanical turntable and the two-dimensional angles of each magnetic bearing from the high-speed measurement and acquisition unit to determine the position and orientation of the two-dimensional mechanical turntable and the magnetic bearing tracking mechanism assembly. It calculates the control electromagnetic force corresponding to the buoyancy start command based on the suspension gap between the electromagnet stator and the float of each magnetic bearing, and uses it to send the buoyancy start command to the magnetic bearing tracking mechanism. The position sensor module collects the magnetic bearing suspension position of the magnetic bearing assembly relative to the float part and the angle towards the tracking target for subsequent precise pointing control; The power amplifier module amplifies and filters the start-up command output by the high-performance control processing unit. The communication interface is used for signal format conversion between modules.

[0036] The displacement variation range of the magnetic bearing is less than 1 mm. The magnetic bearing assembly adopts an integrated custom machining design. The mechanical assembly error of the float part is less than 50 micrometers to ensure the coordinated operation of each magnetic bearing. The accuracy of the eddy current sensor exceeds ±0.1 arcseconds.

[0037] The following description, in conjunction with the accompanying drawings and preferred embodiments, provides further details: In the current embodiment, a control system based on a high-precision angle tracking mechanism using magnetic bearings is proposed for precise tracking control of space targets. The system employs a composite rotating platform combining a two-dimensional mechanical turntable and a magnetic bearing tracking mechanism, such as... Figure 1 The diagram shown is a closed-loop control block diagram of the control system. This system can fully utilize the large rotation range and high speed of the two-dimensional mechanical turntable, and also leverage the precise angle control characteristics of the magnetic bearing tracking mechanism to achieve the goal of rapid acquisition and precise tracking control of the target over a wide range.

[0038] The precise angle tracking control method specifically includes the following steps: S1: The control method and system for a high-precision angle tracking mechanism based on magnetic bearings need to include: a two-dimensional mechanical turntable, a magnetic bearing tracking mechanism, and a corresponding information processing and control module. The two-dimensional mechanical turntable can rotate omnidirectionally, i.e., azimuth range of 0°~360° and pitch range of -90°~90°. The stator of the magnetic bearing tracking mechanism is mechanically connected to the inner frame of the turntable, enabling coarse pointing control by following the turntable's movement. The float of the magnetic bearing tracking mechanism interacts with the stator through four magnetic bearings (named magnetic bearing 1 to magnetic bearing 4) installed at 90° intervals, achieving angle control of the gimbal mounted above the float. Each magnetic bearing has two degrees of freedom, and the two-dimensional angle control of the magnetic bearing tracking mechanism is achieved through electromagnetic force combinations. The electromagnet configuration and coordinate relationship of each magnetic bearing are as follows... Figure 2 As shown, in the coordinate system of the magnetic bearing body, an E-type electromagnet is used, with two magnetic poles on each side (up, down, left, and right).

[0039] S2: Before performing precise pointing control, the magnetic bearing tracking mechanism needs to be adjusted to be near the target direction using a two-dimensional turntable. Due to the influence of turntable angle measurement accuracy, motor control accuracy, and mechanical bearing vibration, as well as the current state of mechanical turntable control accuracy, a pointing deviation of less than 0.02°, approximately 72″, is achievable. This enables coarse alignment control of the target.

[0040] S3: After the magnetic bearing tracking mechanism is powered on, the eddy current sensor installed on each magnetic bearing detects the change in the suspension gap between the electromagnet stator and the float. For example... Figure 3 As shown, these gap values ​​represent analog voltage quantities reflecting the positional changes of the magnetic bearing float in the X and Z axes of the magnetic bearing coordinate system. After rapid sampling, these values ​​are provided to the magnetic bearing drive controller (x1, z1, x2, z2, x3, z3, x4, z4). Based on these values, the magnetic bearing controller calculates the translational displacement of the float and the levitation control algorithm, outputs the corresponding control current, and generates the corresponding control electromagnetic force, thereby achieving closed-loop control of the magnetic bearing's levitation position.

[0041] The calculation method for the translational displacement of the float platform of the magnetic bearing mechanism is as follows:

[0042] The position and attitude of the float platform can be uniquely determined by the combined action of any three magnetic bearing assemblies. The primary magnetic bearing assembly for three-point positioning uses a PID controller, while the zero-position holding function of the fourth magnetic bearing uses a PD controller. Based on the system parameter relationships determined by the following formula, the control parameters are designed ( , , The possible values ​​of ) are:

[0043]

[0044]

[0045] in: The selected system cutoff angular frequency; For the selected system Damping ratio; These are parameters related to the current stiffness coefficient of magnetic bearings; These are parameters related to the displacement stiffness coefficient of the magnetic bearing; It is used to adjust the system deviation integral capability; when it is 0, it is PD control.

[0046] S4: After adjusting the control parameters of the four bearings, the float platform began to float, effectively isolating the high-frequency vibrations of the mechanical turntable and achieving stable pointing control. However, the pointing accuracy still needs fine-tuning, i.e., precisely adjusting the levitation zero position of the float platform. The specific adjustment method involves calculating the levitation zero position correction amount for each magnetic bearing based on the installation relationship of the four magnetic bearings. The calculation method for the rotation angle of the float platform using the magnetic bearing mechanism is as follows:

[0047] Where: L is the installation span between two diagonally opposite magnetic bearings. , This is the pitch angle of the float platform. In actual use, a reference control value can be selected based on the installation relationship between the magnetic bearing position and the measurement coordinate system. This is the azimuth angle of the float platform.

[0048] S5: The control system adopts a distributed magnetic bearing assembly architecture and also needs to include a high-speed measurement and acquisition unit, a high-performance control processing unit, a position sensor module, a power amplifier module, and a communication interface to achieve efficient control of the magnetic bearing tracking mechanism. Since the displacement range of the magnetic bearing is generally less than 1mm, in order to accurately control the direction of the float platform when multiple magnetic bearings are combined, the customized magnetic bearing modules need to be machined as a single unit, and the float assembly needs to be precisely assembled and adjusted to ensure that the overall mechanical assembly error is on the order of 50 micrometers, thereby ensuring the coordinated operation of the four magnetic bearings.

[0049] This embodiment discloses a control method and system for a magnetic bearing-type precision angle tracking mechanism. The proposed device and method have a clear principle and well-defined process, fully utilizing the large rotation range and high speed of a two-dimensional mechanical turntable, while also leveraging the precise angle control characteristics of the magnetic bearing tracking mechanism. The system architecture is clear and possesses good engineering feasibility, effectively solving the problems of poor dynamic response and insufficient precision in traditional bearing control. By selecting a suitable eddy current sensor and optimizing control parameters and a real-time zero-position correction angle tracking strategy, micron-level magnetic bearing position control accuracy can be achieved, with the corresponding angle control accuracy reaching or exceeding ±0.1 arcseconds, significantly improving the tracking and pointing accuracy of the payload. This method and system are suitable for high-precision, high-stability precision equipment and tracking and pointing applications.

[0050] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

[0051] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A high-precision angle tracking mechanism control system based on magnetic bearings, characterized in that: It includes a two-dimensional mechanical turntable, a magnetic bearing tracking mechanism, and an information processing and control module, wherein: The magnetic bearing tracking mechanism includes a stator section, a float section, and magnetic bearing assemblies. The stator section is mechanically connected to the inner frame of a two-dimensional mechanical turntable and performs coarse directional control as the turntable rotates. The float section has magnetic bearing assemblies installed at intervals, and the buoyancy control is achieved through the magnetic force between the magnetic bearing assemblies and the stator section. The magnetic bearing tracking mechanism receives buoyancy commands from the information processing and control module and adjusts the position of each magnetic bearing in the magnetic bearing assembly to perform buoyancy control. The two-dimensional mechanical turntable receives control commands from the information processing and control module to perform mechanical pointing control; it adjusts the mechanical pointing with magnetic force according to the start-up and levitation control amplitude of the magnetic bearing tracking mechanism to accurately point to the tracking target; The information processing and control module generates control commands based on the inner frame of the two-dimensional mechanical turntable and the orientation of the tracking target, and sends them to the two-dimensional mechanical turntable to adjust its mechanical orientation. After the mechanical orientation of the two-dimensional turntable is adjusted, the module samples the suspension gap between the float and the magnetic bearing assembly, calculates the control electromagnetic force, and uses the control electromagnetic force to generate a buoyancy start command, which is sent to the magnetic bearing tracking mechanism to adjust the magnetic bearing suspension position of the magnetic bearing assembly relative to the float.

2. The high-precision angle tracking mechanism control system based on magnetic bearings according to claim 1, characterized in that: The omnidirectional rotation range of the two-dimensional mechanical turntable is 360° omnidirectional in the turntable orientation and -90° to 90° in the pitch direction; the magnetic bearing assembly consists of individual magnetic bearings, with four magnetic bearings installed on the float part, evenly distributed in a circumferential pattern at 90° intervals. During the buoyancy control phase, each magnetic bearing generates a magnetic force with the stator part to achieve the angle adjustment of the float part relative to the target being tracked. Each magnetic bearing is provided with two degrees of freedom for control, and the two-dimensional angle control of each magnetic bearing is achieved through the magnetic force.

3. The high-precision angle tracking mechanism control system based on magnetic bearings according to claim 1, characterized in that: Each magnetic bearing in the magnetic bearing assembly is equipped with an eddy current sensor to monitor the change in the suspension gap between the electromagnet stator and the float of each magnetic bearing. The suspension gap is used to reflect the voltage analog quantity reflecting the change in the position of the float part in the X-axis and Z-axis directions of the magnetic bearing coordinate system.

4. The high-precision angle tracking mechanism control system based on magnetic bearings according to claim 3, characterized in that: The information processing and control module generates a buoyancy command containing control electromagnetic force parameters based on the collected suspension gap and sends it to the four magnetic bearings of the magnetic bearing tracking mechanism. The magnetic bearings generate control current and corresponding control electromagnetic force according to the corresponding control electromagnetic force, and adjust the suspension position of the magnetic bearing group relative to the float part and the angle towards the tracking target to complete the buoyancy control closed loop.

5. The high-precision angle tracking mechanism control system based on magnetic bearings according to claim 4, characterized in that: During the buoyancy control process, any three of the four magnetic bearings in the float section can be selected to perform joint actions based on the specific orientation of the tracking target to determine the pose of the float platform. PID control is used to achieve three-point positioning to adjust the pose of the magnetic bearings relative to the float platform. The fourth magnetic bearing is kept at zero position through PD control.

6. The high-precision angle tracking mechanism control system based on magnetic bearings according to claim 5, characterized in that: The translational displacement of the float portion of the magnetic bearing tracking mechanism occurs after the buoyancy control begins. The calculation method for the translational displacement is as follows: In the formula, , for the first i The displacement of a magnetic bearing in the X-axis direction of its body coordinate system. i =1,2,3,4; For the first i A magnetic bearing on its body coordinate axis Z Displacement in the direction, i =1,2,3,4; x This represents the displacement of the magnetic bearing float along its coordinate axis X. y This represents the displacement of the magnetic bearing float along its Y-axis. z This represents the displacement of the magnetic bearing float along its coordinate axis Z. The three-point positioning of the float platform is based on control parameters. , , Implementation, control parameters , , The calculation method is as follows: In the formula, The selected system cutoff angular frequency; For the selected system Damping ratio; These are parameters related to the current stiffness coefficient of magnetic bearings; These are parameters related to the displacement stiffness coefficient of the magnetic bearing; When used to adjust the coefficient of the deviation integral capability When the value is 0, the control mode changes from PID control to PD control.

7. A high-precision angle tracking mechanism control system based on magnetic bearings according to claim 6, characterized in that: After the buoyancy control is initiated, the float section initiates buoyancy and isolates the vibration of the two-dimensional mechanical turntable. By calculating the rotation angle of the float platform, the suspension zero-position correction amount of each magnetic bearing is calculated using the rotation angle of the float platform and the relative installation relationship of each magnetic bearing. Based on the suspension zero-position correction amount, buoyancy control is implemented to change the position of each magnetic bearing relative to the float platform. After the precise pointing control, the magnetic bearing tracking mechanism and the two-dimensional mechanical turntable assembly complete the tracking process of the target.

8. The high-precision angle tracking mechanism control system based on magnetic bearings according to claim 7, characterized in that: The method for calculating the rotation angle of the float platform is as follows: In the formula, L Install the span for the two diagonally opposite magnetic bearings. , The pitch angle of the float platform is selected as a reference control value based on the installation relationship between the magnetic bearing position and the measurement coordinate system when the float part moves according to the pitch angle. This is the azimuth angle of the float platform.

9. A high-precision angle tracking mechanism control system based on magnetic bearings according to claim 7, characterized in that: The information processing and control module includes a high-speed measurement and acquisition unit, a high-performance control and processing unit, a position sensor module, a power amplifier module, and a communication interface, wherein: The high-speed measurement and acquisition unit is used to acquire the omnidirectional rotation range of the two-dimensional mechanical turntable, the two-dimensional angle of each magnetic bearing, the suspension gap between the electromagnet stator and the float of each magnetic bearing, the magnetic bearing suspension position of the magnetic bearing group relative to the float part and the angle towards the tracking target, and send it to the high-performance control and processing unit for information processing. The high-performance control processing unit receives the omnidirectional rotation range of the two-dimensional mechanical turntable and the two-dimensional angles of each magnetic bearing from the high-speed measurement and acquisition unit to determine the position and orientation of the two-dimensional mechanical turntable and the magnetic bearing tracking mechanism assembly. It calculates the control electromagnetic force corresponding to the buoyancy start command based on the suspension gap between the electromagnet stator and the float of each magnetic bearing, and uses it to send the buoyancy start command to the magnetic bearing tracking mechanism. The position sensor module collects the magnetic bearing suspension position of the magnetic bearing assembly relative to the float part and the angle towards the tracking target for subsequent precise pointing control; The power amplifier module amplifies and filters the start-up command output by the high-performance control processing unit. The communication interface is used for signal format conversion between modules.

10. A high-precision angle tracking mechanism control system based on magnetic bearings according to claim 9, characterized in that: The displacement variation range of the magnetic bearing is less than 1 mm. The magnetic bearing assembly adopts an integrated custom processing design. The mechanical assembly error of the float part is less than 50 micrometers to ensure the coordinated operation of each magnetic bearing. The accuracy of the eddy current sensor exceeds ±0.1 arcseconds.

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