A large-angle high-precision macro-micro hybrid rotary table and a control method thereof

Abstract

The application belongs to the technical field of rotary tables, and specifically discloses a large-angle high-precision macro-micro composite rotary table and a control method thereof. The rotary table comprises a macro-rotation part, a micro-rotation part and an angle measurement part. The macro-rotation part comprises a base, a connecting plate, a load-bearing plate, a macro-rotation motor and a thrust bearing. The connecting plate is fixed to the base by screws. The micro-rotation part comprises a micro-rotation rotary table base, a micro-rotation driver, a ring-shaped grating ruler and a micro-rotation rotary table. The micro-rotation rotary table base is coaxially fixed to the load-bearing plate by screws. The angle measurement part comprises a high-precision angle sensor, a sensor fixing plate, an XY-axis manual displacement platform, a support a and a support b. The large-angle high-precision macro-micro composite rotary table and the control method thereof are adopted to realize large-angle rapid positioning and micro-nanoradian high-precision fine adjustment, and the rotary table has the advantages of simple structure, fast response, low cost and small eddy current loss.

Description

Technical Field

[0001] This invention relates to the field of rotary table technology, and in particular to a large-angle, high-precision macro-micro composite rotary table and its control method. Background Technology

[0002] High-precision rotary stages are core components for complex machining and high-precision measurement in aerospace, semiconductor manufacturing, medical equipment, and precision machining fields. Their angular positioning accuracy directly determines machining quality and measurement precision. Current traditional technologies struggle to meet the requirements for micro-radian and nanoradian-level angular positioning, making rotary stages with large angles, ultra-high precision, and rapid response a key research and development direction in advanced manufacturing. Existing rotary positioning devices generally suffer from difficulties in simultaneously handling large-angle rotation and ultra-high-precision positioning. Some are structurally complex, have high manufacturing costs, and suffer from significant eddy current losses, making it impossible to achieve both coarse positioning and fine adjustment, thus hindering the development of high-end precision manufacturing. Summary of the Invention

[0003] The purpose of this invention is to provide a large-angle, high-precision macro-micro composite rotary stage and its control method, which realizes large-angle rapid positioning and micro-nano-arc-level high-precision fine adjustment. It has a simple structure, fast response, low cost, and low eddy current loss.

[0004] To achieve the above objectives, the present invention provides a large-angle, high-precision macro-micro composite rotary stage, comprising a macro rotation part, a micro rotation part, and an angle measurement part. The macro rotation part includes a base, a connecting plate, a load-bearing plate, a macro rotation motor, and a thrust bearing. The connecting plate is fixed to the base with screws to ensure coaxiality. The thrust bearing race is interference-fitted into the stepped hole of the connecting plate, and the race is interference-fitted with the load-bearing plate. The macro rotation part drives the micro rotation part in a zero-backlash manner. The micro-rotation part includes a micro-rotation rotary table base, a micro-rotation driver, a circular grating ruler, and a micro-rotation rotary table; the micro-rotation rotary table base is coaxially fixed to the load-bearing plate with screws. The angle measurement section includes a high-precision angle sensor, a sensor mounting plate, an XY-axis manual displacement platform, bracket a, and bracket b; the XY-axis manual displacement platform is fixed to the connecting plate via bracket a and bracket b.

[0005] Preferably, the macro motor is bolted to the connecting plate, and the output end of the macro motor is connected to the load-bearing plate via a key to transmit torque, and is axially fixed by set screws.

[0006] Preferably, the micro-rotation driver is fixed to the micro-rotation table base with screws, and the inner ring of the circular grating ruler is fixed to the micro-rotation table.

[0007] Preferably, the high-precision angle sensor is fixed to a sensor mounting plate, and the sensor mounting plate is connected to the XY-axis manual displacement platform.

[0008] Preferably, the micro-rotation actuator includes a locking screw, a cooling copper tube, a strip magnetic yoke, a super magnetostrictive block, a wedge-shaped magnetic guide block, a bias coil, an excitation coil, and an arc-shaped magnetic guide block. The wedge-shaped magnetic guide block and the super magnetostrictive block are arranged circumferentially. The bias coil is wound coaxially around the outer side of the super magnetostrictive block with the excitation coil on the inside and the arc-shaped magnetic guide block on the outside. The arc-shaped magnetic guide block is arranged circumferentially around the excitation coil. The strip magnetic yoke is arranged at the end of the excitation coil. The cooling copper tube is arranged in the gap between the excitation coil and the arc-shaped magnetic guide block. The locking screw is installed at the end of the micro-rotation actuator to tighten the super magnetostrictive block and the wedge-shaped magnetic guide block.

[0009] Preferably, the super magnetostrictive block is made of super magnetostrictive material, is in the shape of a truncated pyramid, and is arranged in a bamboo-like manner with the wedge-shaped magnetic conductive block.

[0010] This invention also provides a control method for a large-angle, high-precision macro-micro composite rotary stage, comprising the following steps: S1: For the macro rotation part, based on the mathematical model of the macro rotation motor, establish the control model of the macro rotation part of the large-angle high-precision macro-micro composite rotary table; S2: For the micro-rotation part, a control model for the micro-rotation part of the large-angle high-precision macro-micro composite rotary table is established based on the Jiles-Atherton hysteresis model. S3: Based on the control models of the macro rotation part and the micro rotation part, and combined with the control requirements of the rotation angle, macro rotation and micro rotation control strategies are formed; S4: Based on the rotation control requirements, obtain the optimal control parameters through simulation software and generate the running code for the rotation control strategy; S5: Use the USART1 serial communication interface between the host computer and the microcontroller to establish communication via RS232 serial port. Use a downloader to establish communication with the JTAG / SWD module of the microcontroller through the compiler. Also, establish communication between the driver boards of the macro rotation part and the micro rotation part and the advanced timers TIM1 and TIM8 of the microcontroller respectively. Download the running code to the microcontroller to control the rotation of the large-angle high-precision macro-micro composite rotary table. S6: A high-precision angle sensor collects angle data in real time and provides feedback to control the PWM duty cycle of the macro rotation; using the angle difference as the target, the current of the micro rotation driver is adjusted to achieve ultra-high precision positioning.

[0011] The advantages and beneficial effects of the large-angle, high-precision macro-micro composite rotary stage and its control method described above are as follows: 1. This invention features a coaxial integrated design of a macro-rotation part with a macro-rotation motor as the main body and a micro-rotation part with a bamboo-joint drive group consisting of a super magnetostrictive block and a wedge-shaped magnetic guide block. The macro-rotation part drives the micro-rotation part in a zero-backlash manner, which has the characteristics of fast response, large-angle positioning and ultra-high precision. When the macro-micro composite rotary table with large-angle ultra-high precision positioning is working, the macro-rotation part first completes the large-angle rotation, and then the micro-rotation part performs micro-arc and nano-arc level angle adjustment, thereby improving processing accuracy and efficiency.

[0012] 2. The design of the super magnetostrictive block and wedge-shaped magnetic block bamboo joint drive group of the present invention has the following advantages: easy to process and reduce cost; reduced eddy current loss; stacked structure improves magnetic field strength.

[0013] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a large-angle, high-precision macro-micro composite rotary stage structure according to the present invention. Figure 2 This is a cross-sectional view of a large-angle, high-precision macro-micro composite rotary table according to the present invention. Figure 3 This is a cross-sectional view of a micro-rotation actuator in a large-angle, high-precision macro-micro composite rotary stage of the present invention. Figure 4 This is a schematic diagram of the base structure in a large-angle, high-precision macro-micro composite rotary stage of the present invention. Figure 5 This is a schematic diagram of the connecting plate structure in a large-angle, high-precision macro-micro composite rotary stage of the present invention. Figure 6 This is a schematic diagram of the load-bearing plate structure in a large-angle, high-precision macro-micro composite rotary table of the present invention. Figure 7 This is a schematic diagram of the circular grating ruler structure in a large-angle, high-precision macro-micro composite rotary stage of the present invention. Figure 8 This is a schematic diagram of the sensor fixing plate structure in a large-angle high-precision macro-micro composite rotary stage of the present invention; Figure 9 This is a schematic diagram of the support structure a in a large-angle, high-precision macro-micro composite rotary stage of the present invention; Figure 10 This is a schematic diagram of the support structure b in a large-angle, high-precision macro-micro composite rotary stage of the present invention. Figure 11 This is a schematic diagram of the strip magnetic yoke structure in a large-angle, high-precision macro-micro composite rotary stage of the present invention; Figure 12 This is a schematic diagram of the bamboo-joint arrangement of the super magnetostrictive block and the wedge-shaped magnetic conductive block in a large-angle high-precision macro-micro composite rotary stage of the present invention. Figure 13 This is a flowchart of a large-angle, high-precision macro-micro composite rotary stage and its control method according to the present invention. Figure 14 This is a block diagram of a feedforward-feedback control system for a large-angle, high-precision macro-micro composite rotary stage and its control method according to the present invention.

[0015] Figure Labels 1. Base; 2. Connecting plate; 3. Load-bearing plate; 4. Micro-rotation rotary table base; 5. Micro-rotation driver; 6. Circular grating ruler; 7. Micro-rotation rotary table; 8. Angle sensor; 9. Sensor fixing plate; 10. Manual displacement platform; 11. Bracket a; 12. Bracket b; 13. Macro-rotation motor; 14. Thrust bearing; 15. Anti-reverse screw; 16. Cooling copper pipe; 17. Strip magnetic yoke; 18. Magnetostrictive block; 19. Wedge-shaped magnetic guide block; 20. Bias coil; 21. Excitation coil; 22. Arc-shaped magnetic guide block. Detailed Implementation

[0016] The technical solution of the present invention will be further described below through embodiments.

[0017] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0018] The following examples are not intended to limit the invention, but are only for illustration. Unless otherwise specified, the experimental methods used in the following examples are generally performed under conventional conditions. Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0019] Example 1 like Figure 1As shown, a macro-micro composite rotary stage for large-angle ultra-high precision positioning includes a macro-rotation part, a micro-rotation part, and an angle measurement part. The macro-rotation part includes a base 1 (as shown in the image). Figure 4 (as shown), connecting plate 2, load-bearing plate 3 (as shown) Figure 6 (as shown), macro rotating motor (e.g., permanent magnet synchronous motor, etc.) 13, thrust bearing 14; wherein, the four countersunk holes on the upper end face of the connecting plate 2 and the four threaded holes on the upper end face of the base 1 are connected and fixed by screws to ensure coaxiality (e.g. Figure 5 As shown). Figure 2 As shown, the thrust bearing 14 seat ring is installed in the stepped hole of the connecting plate 2, and the connection is achieved by the interference fit between the hole and the shaft; the four through holes on the upper end face of the macro motor 13 are fastened to the four countersunk holes on the stepped hole of the connecting plate 2 by bolts and nuts to ensure coaxiality; the thrust bearing 14 shaft ring is connected to the load-bearing plate 3 by the interference fit between the hole and the shaft; the rotating shaft of the macro motor 13 is connected to the middle hole of the load-bearing plate 3 by the interference fit between the hole and the shaft, and the key on the rotating shaft of the macro motor 13 is connected to the keyway on the center hole of the load-bearing plate 3 to achieve the function of transmitting torque, and is installed in the set screw to the set thread hole of the load-bearing plate 3 to achieve the purpose of axial fixation of the rotating shaft of the macro motor 13. The macro rotating part is driven by the micro rotating part in a zero transmission backlash manner (e.g., direct drive).

[0020] The micro-rotation section includes a micro-rotation stage base 4, a micro-rotation actuator 5, and a circular grating ruler 6 (e.g., Figure 7 As shown), the micro-rotating rotary table 7. Figure 3 As shown, the micro-rotation actuator 5 includes a locking screw 15, a cooling copper pipe 16, a bar magnetic yoke 17, a super magnetostrictive block 18, a wedge-shaped magnetic guide block 19, a bias coil 20, an excitation coil 21, and an arc-shaped magnetic guide block 22. The four threaded holes below the micro-rotation actuator 5 are connected and fixed to the four countersunk holes at the center of the micro-rotation stage base 4 by screws. The inner ring of the circular grating ruler 6 is fixed at the center of the largest diameter circle on the micro-rotation stage 7. The ten threaded holes distributed circumferentially on the micro-rotation stage base 4 are connected to the load-bearing plate in the macro-rotation section. Ten countersunk holes distributed circumferentially on the upper part of the device are connected and fixed by screws to ensure coaxiality; the wedge-shaped magnetic guide block 19 and the super magnetostrictive block 18 are arranged circumferentially, with the bias coil 20 inside and the excitation coil 21 outside, coaxially wound on its outer side; the arc-shaped magnetic guide block 22 is arranged circumferentially along the excitation coil 21; the strip magnetic yoke 17 is arranged at the end of the excitation coil 21; the cooling copper tube 16 is arranged in the gap between the excitation coil 21 and the arc-shaped magnetic guide block 22; the anti-reverse screw 15 is installed at the end of the micro-rotation driver to tighten the super magnetostrictive block 18 and the wedge-shaped magnetic guide block 19. The super magnetostrictive block 18 is made of super magnetostrictive material and is in the shape of a truncated pyramid, arranged in a bamboo-like manner with the wedge-shaped magnetic guide block 19 (e.g., ...). Figure 12 (As shown).

[0021] The bar yoke 17 forms a closed magnetic circuit, constrains the direction of the magnetic field, reduces leakage magnetic field and eddy current loss, and improves magnetic energy utilization.

[0022] The super magnetostrictive block 18 generates micro-nano-level controllable linear deformation under the action of a magnetic field, providing high-precision driving force for micro-rotation.

[0023] The wedge-shaped magnetic guide block 19 and the super magnetostrictive block 18 work together to form a bamboo-joint amplification structure, which conducts deformation and drives the micro-rotation table to rotate; at the same time, it assists in magnetic conduction and enhances the uniformity of the magnetic field.

[0024] A DC current is applied to the bias coil 20 to generate a static bias magnetic field, which makes the super magnetostrictive block 18 work in the linear range and eliminates the influence of the hysteresis loop.

[0025] A controllable driving current is passed through the excitation coil 21 to generate a dynamically modulated magnetic field, which precisely controls the deformation size and speed of the supermagnetostrictive block 18.

[0026] A magnetic field along the arc length direction can be provided by using an excitation coil 21 and a bias coil 20, or by using an excitation coil 21 and a permanent magnet arranged along the arc direction.

[0027] Cooling water is introduced into the cooling copper tube 16 to remove the heat generated by the coil and magnetostrictive block during operation, suppress thermal deformation, and ensure long-term high-precision operation.

[0028] The micro-rotation actuator 5 is the core component for achieving high-precision rotary drive at the micro-nano level. It is mounted at the center of the micro-rotation stage base 4 and fixed to the base via threaded holes. Internally, it consists of anti-reverse screws 15, cooling copper pipes 16, and a strip magnetic yoke 17 (e.g., ...). Figure 11 As shown), the super magnetostrictive block 18, wedge-shaped magnetic guide block 19, bias coil 20, excitation coil 21, and arc-shaped magnetic guide block 22 are arranged in a coaxial circumference to form a closed-loop magnetic circuit and a precision drive structure.

[0029] The anti-reverse screw 15 provides a constant axial preload, ensuring that the super magnetostrictive block 18 and the wedge-shaped magnetic guide block 19 fit tightly, preventing impact and loosening, and ensuring stable drive accuracy.

[0030] The angle measurement section includes a high-precision angle sensor 8 and a sensor mounting plate 9 (such as...). Figure 8 (as shown), XY axis manual displacement platform 10, bracket a11 (as shown) Figure 9 As shown), bracket b12 (as shown) Figure 10(As shown); the two through holes of the high-precision angle sensor 8 are connected and fixed to the two threaded holes of the sensor mounting plate 9 by screws; the four countersunk holes of the sensor mounting plate 9 are connected and fixed to the four threaded holes above the XY-axis manual displacement platform 10 by screws; the four countersunk holes above the bracket a11 are connected and fixed to the four threaded holes below the XY-axis manual displacement platform 10 by screws; the two countersunk holes below the bracket a11 are fastened to the two countersunk holes above the bracket b12 by bolts and nuts; the two countersunk holes below the bracket b12 are connected and fixed to the two threaded holes at the keyway of the macro rotating part connecting plate 2 by screws.

[0031] First, install the macro-rotation part, ensuring the coaxiality of the base 1, connecting plate 2, load-bearing plate 3, macro-rotation motor 13, and thrust bearing 14; then install the micro-rotation part, fixing the micro-rotation turntable base 4 to the load-bearing plate 3; finally, install the angle measurement part, adjusting the XY-axis manual displacement platform 10 to align the high-precision angle sensor 8 with the detection position.

[0032] The working principle of the macro-micro composite rotary stage with large-angle ultra-high precision positioning is as follows: A target rotation value is set, the macro rotation motor 13 rotates, transmitting torque to the load-bearing plate 3 via a key connection, driving the micro rotation structure to rotate. The high-precision angle sensor 8 of the angle measurement section measures the actual macro rotation angle and calculates the difference between it and the target rotation angle; this difference is the target rotation angle value for the micro rotation section. The bias coil 20 and excitation coil 21 in the micro rotation driver are energized to generate a magnetic field. The magnetostrictive block 18 deforms under the magnetic field, causing the magnetostrictive block 18 and the wedge-shaped magnetic block 19 to deform in a bamboo-like manner, thus driving the micro rotation rotary stage to rotate. The high-precision angle sensor 8 measures the rotation angle in real time, compares it with the target angle value, and adjusts the current flowing through the bias coil 20 and excitation coil 21 to achieve the target rotation angle.

[0033] Example 2 A control method for a large-angle, high-precision macro-micro composite rotary stage, such as Figure 13 and Figure 14 As shown, it includes the following steps: S1: For the macro-rotation part, based on the mathematical model of the macro-rotation motor, a control model for the macro-micro composite rotary table with large-angle ultra-high precision positioning is established.

[0034] S2: For the micro-rotation part, based on the Jiles-Atherton hysteresis model, a control model for the micro-rotation of the macro-micro composite rotary table with large-angle ultra-high precision positioning is established.

[0035] The Jiles-Atherton hysteresis model, based on the domain wall theory of ferromagnetic materials, reflects the applied magnetic field. H and magnetization M The relationship between them is as follows: In the formula, H e The effective magnetic field of the magnetic material is represented by α; α represents the domain wall interaction coefficient. H σ Indicates prestress σ 0 The induced magnetic field formed; α'=α +9 λ s σ 0 / (2 u 0 M s 2 ) represents the equivalent parameter of the magnetic domain interaction within the GMM rod; M an Indicates hysteresis-free magnetization; M s The saturation magnetization; a The shape factor of the hysteresis-free magnetization; M irr It is the irreversible magnetization intensity; c The invertibility coefficient; M rev It is the reversible magnetization intensity; δ is a sign constant for the direction of the magnetic field; k This is the irreversible loss coefficient.

[0036] Under a constant magnetic field strength, the magnetostrictive strain of a circular arc-shaped supermagnetostrictive rod is related to the total magnetization. M and magnetostrictive displacement X The relationship is: In the formula, γ The magnetostriction coefficient is 1. l The arc length of the arc-shaped supermagnetostrictive rod.

[0037] Compensation angle α It can be represented as: ; In the formula, R The radius of rotation of the arc-shaped supermagnetostrictive rod is given.

[0038] S3: Based on the control models of the macro rotation and micro rotation, and combined with the control requirements of the rotation angle, macro rotation and micro rotation control strategies are formed.

[0039] S4: Based on the rotation control requirements, obtain the optimal control parameters through simulation software (such as Matlab / Simulink) and generate the running code for the rotation control strategy.

[0040] S5: Use the USART1 serial communication interface between the host computer and the microcontroller to establish communication via RS232 serial line. Use a downloader to establish communication with the microcontroller's JTAG / SWD module through the compiler. Also, establish communication between the driver boards of the macro rotation part and the micro rotation part and the microcontroller's advanced timers TIM1 and TIM8 respectively. Download the running code to the microcontroller to control the rotation of the macro-micro composite rotary table with large-angle ultra-high precision positioning.

[0041] S6: The actual rotation angle of the macro-rotation part is measured in real time by a high-precision angle sensor. The actual rotation angle is compared with the target rotation angle, and the rotation angle feedback signal is acquired by a high-precision data acquisition card. Communication is established with the microcontroller's serial communication interface USART2 via an RS485 serial port. The Modbus-RTU protocol is used to communicate with the microcontroller to control the PWM duty cycle input to the macro-rotation part, thereby realizing the rotation angle control of the macro-rotation part. After the macro-rotation ends, the actual rotation angle is compared with the target rotation angle, and the difference is used as the target value of the micro-rotation part. The magnitude of the current input to the micro-rotation driver is adjusted until the target angle value is reached, thereby realizing large-angle ultra-high precision macro-micro composite positioning.

[0042] USART1 / USART2: Universal Synchronous Asynchronous Receiver / Transmitter 1 / Universal Synchronous Asynchronous Receiver / Transmitter 2.

[0043] RS232: A physical interface standard for serial data communication (defining voltage signals, connector types, etc., for point-to-point asynchronous communication between a host computer and a microcontroller).

[0044] JTAG: International standard test protocol interface (used for chip internal debugging, boundary scan testing, and program downloading, connected to the microcontroller through a compiler and downloader).

[0045] SWD: Two-wire serial debug interface (introduced by ARM, it is a simplified alternative to JTAG and is also used for program downloading and online debugging).

[0046] TIM1 / TIM8: Advanced control timer modules inside the microcontroller.

[0047] RS485: A serial communication physical layer standard for differential signal transmission (supporting long-distance, multi-node communication, used for industrial fieldbus connection between high-precision data acquisition cards and microcontrollers).

[0048] Modbus-RTU protocol: an industrial serial communication protocol based on master-slave architecture (using a compact binary encoding format for data interaction between a microcontroller and a data acquisition card on the RS485 physical layer).

[0049] PWM: Pulse Width Modulation technology (by changing the high-level duration (duty cycle) of a square wave pulse, the average voltage or current input to the macro-rotation drive board is controlled, thereby adjusting the motor speed and angle).

[0050] Therefore, this invention adopts the above-mentioned large-angle high-precision macro-micro composite rotary stage and its control method, which integrates macro and micro coaxially, taking into account both large angle and ultra-high precision positioning; the bamboo-joint type super magnetostrictive drive structure is easy to process, low in cost, has low eddy current loss and high magnetic field strength; the feedforward-feedback control has fast response and stable positioning, improving the efficiency and quality of precision machining.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A large-angle, high-precision macro-micro composite rotary stage, characterized in that: It includes a macro-rotation section, a micro-rotation section, and an angle measurement section. The macro-rotation section includes a base, a connecting plate, a load-bearing plate, a macro-rotation motor, and a thrust bearing. The connecting plate is fixed to the base with screws to ensure coaxiality. The thrust bearing race is interference-fitted into the stepped hole of the connecting plate, and the race is interference-fitted with the load-bearing plate. The macro-rotation section is driven by a direct-drive motor to drive the micro-rotation section. The micro-rotation part includes a micro-rotation rotary table base, a micro-rotation driver, a circular grating ruler, and a micro-rotation rotary table; The micro-rotation rotary table base is fixed to the load-bearing plate with coaxial screws; The angle measurement section includes a high-precision angle sensor, a sensor mounting plate, an XY-axis manual displacement platform, bracket a, and bracket b; the XY-axis manual displacement platform is fixed to a connecting plate via bracket a and bracket b; the high-precision angle sensor is fixed to the sensor mounting plate, and the sensor mounting plate is connected to the XY-axis manual displacement platform. The micro-rotation actuator is fixed to the micro-rotation stage base with screws, and the inner ring of the circular grating ruler is fixed to the micro-rotation stage. The micro-rotation actuator includes a locking screw, a cooling copper tube, a strip magnetic yoke, a super magnetostrictive block, a wedge-shaped magnetic guide block, a bias coil, an excitation coil, and an arc-shaped magnetic guide block. The super magnetostrictive block is made of super magnetostrictive material and is in the shape of a truncated pyramid. Multiple wedge-shaped magnetic guide blocks and multiple super magnetostrictive blocks are arranged alternately along the circumference in a bamboo-like arrangement. The bias coil is coaxially wound on the outside of the super magnetostrictive block with the excitation coil on the inside. The arc-shaped magnetic guide block is arranged along the circumference of the excitation coil. The strip magnetic yoke is arranged at the end of the excitation coil, and the cooling copper tube is arranged in the gap between the excitation coil and the arc-shaped magnetic guide block. The locking screw is installed at the end of the micro-rotation actuator to tighten the super magnetostrictive block and the wedge-shaped magnetic guide block.

2. The large-angle high-precision macro-micro composite rotary stage according to claim 1, characterized in that: The macro motor is bolted to the connecting plate, and the output end of the macro motor is connected to the load-bearing plate via a key to transmit torque, and is axially fixed by set screws.

3. A control method for a large-angle, high-precision macro-micro composite rotary stage according to any one of claims 1-2, characterized in that, The steps include the following: S1: For the macro rotation part, based on the mathematical model of the macro rotation motor, establish the control model of the macro rotation part of the large-angle high-precision macro-micro composite rotary table; S2: For the micro-rotation part, based on the Jiles-Atherton hysteresis model, a control model for the micro-rotation part of the large-angle high-precision macro-micro composite rotary table is established. S3: Based on the control models of the macro rotation part and the micro rotation part, and combined with the control requirements of the rotation angle, macro rotation and micro rotation control strategies are formed; S4: Based on the rotation control requirements, obtain the optimal control parameters through simulation software and generate the running code for the rotation control strategy; S5: Use the USART1 serial communication interface between the host computer and the microcontroller to establish communication via RS232 serial port. Use a downloader to establish communication with the JTAG / SWD module of the microcontroller through the compiler. Also, establish communication between the driver boards of the macro rotation part and the micro rotation part and the advanced timers TIM1 and TIM8 of the microcontroller respectively. Download the running code to the microcontroller to control the rotation of the large-angle high-precision macro-micro composite rotary table. S6: A high-precision angle sensor collects angles in real time and provides feedback to control the macro rotation PWM duty cycle; By adjusting the current of the micro-rotation actuator with the angular difference as the target, ultra-high precision positioning can be achieved.

Images