A high dynamic response four-axis motion platform

Abstract

The invention relates to a high dynamic response four-axis motion platform. The T-axis rotation platform is embedded in the Y-axis mobile platform. The T-axis rotation platform is driven by a driving coil and a permanent magnet. A lower compensation component and an upper compensation component composed of a plurality of strain tiles distributed in a circumferential array are arranged on the rotating shaft. The strain tiles adopt a three-layer structure of a polyimide base layer, a first strain layer made of an electrostrictive material, and a second strain layer made of a piezoelectric material. A piezoelectric material induction ring with an embedded optical fiber Bragg sensor is arranged between the first and second bearings. The control method comprises real-time monitoring of stress changes, judging whether a deviation or vibration threshold is reached, determining an adjustment target, amplitude and direction, controlling deformation of the strain layer to compensate for balance and horizontal deviations, suppressing vibration, and realizing adaptive compensation control. The platform realizes high dynamic response, active vibration suppression, adaptive intelligent compensation control and highly integrated design, and improves motion accuracy, stability and reliability.

Description

Technical Field

[0001] The present invention relates to a high dynamic response four-axis motion platform, and in particular to a high dynamic response four-axis motion platform applied in the technical field of high-precision motion control. Background Art

[0002] With the rapid development of modern industry, high-speed and high-precision motion control technology has been widely used in many fields such as mechanical manufacturing, aerospace, biomedicine, etc. As a key device for realizing multi-degree-of-freedom motion control, the dynamic response performance and motion accuracy of the four-axis motion platform directly affect the technological progress in related fields.

[0003] Chinese invention patent CN117434708 discloses a microscopic laser system posture adjustment precision motion platform, which realizes precise positioning of the microscopic laser system through an XY motion platform, and uses air-floating components to absorb the vibration caused by the guide rail, providing a superior performance foundation for the microscopic laser system. Although the platform realizes precise positioning and posture adjustment, it lacks optimized design for dynamic response characteristics, which may affect its positioning accuracy and stability under high-speed motion conditions.

[0004] Chinese invention patent CN101804568 discloses a linear motor driven air suspension motion platform, which adopts linear motor drive and air suspension structure, and has the advantages of simple structure and high cost performance. However, the platform lacks a compensation mechanism for multi-axis coupled motion. When moving at high speed and large stroke, the posture deviations between the axes will gradually accumulate, affecting the motion accuracy. In addition, the platform structure has low rigidity and is prone to deformation under high load conditions, reducing positioning accuracy.

[0005] In the field of high-end manufacturing, such as aircraft engine blade processing and 3C precision electronic assembly, extremely high requirements are placed on the speed, accuracy and stability of the motion platform. Although the four-axis motion platform in the existing technology meets the motion control requirements to a certain extent, it still faces problems such as insufficient dynamic response, multi-axis coupling error accumulation, and high vibration noise under extreme working conditions such as high speed, high acceleration, and high load, which limits the performance improvement and application expansion of the product. Summary of the invention

[0006] In view of the above-mentioned prior art, the technical problem to be solved by the present invention is how to reduce the height of the multi-axis motion platform and maintain high dynamic response characteristics, realize multi-axis high-precision motion compensation, and have the ability to actively suppress vibration.

[0007] To solve the above problems, the present invention provides a high dynamic response four-axis motion platform, including an X-axis mobile platform, a Y-axis mobile platform is slidably connected to the top of the X-axis mobile platform, a T-axis rotating platform is rotatably connected inside the Y-axis mobile platform, a Z-axis lifting platform is fixedly connected to the top of the T-axis rotating platform, the top of the T-axis rotating platform is flush with the top of the Y-axis mobile platform, the T-axis rotating platform includes a rotating shaft fixedly connected to the Y-axis mobile platform, the T-axis rotating platform includes a Z-axis fixing ring, a plurality of permanent magnets are fixedly connected to the outer end of the Z-axis fixing ring, a driving coil is fixedly connected to the Y-axis mobile platform and the permanent magnet at the corresponding position, and the permanent magnet is electrically connected to a controller.

[0008] As a further improvement of the present application, a lower compensation component and an upper compensation component are fixedly connected to the outer end of the rotating shaft, and the lower compensation component and the upper compensation component both include a strain ring, and the top and bottom ends of the strain ring are electrically connected to a control ring, and the strain ring is composed of a plurality of strain tiles distributed in a circular array.

[0009] As a further improvement of the present application, the strain shoe includes a base layer, an outer end of the base layer is fixedly connected to a first strain layer, and an inner end of the base layer is fixedly connected to a second strain layer, multiple control rings are electrically connected to the controller, the outer ends of the lower compensation component and the upper compensation component are respectively fixedly connected to a first bearing and a second bearing, and an induction ring is fixedly connected between the first bearing and the second bearing.

[0010] As a further improvement of the present application, the outer ends of the first bearing and the second bearing are fixedly connected to the Z-axis fixing ring, the top of the Z-axis fixing ring is fixedly connected to the Z-axis fixing plate, and the top of the Z-axis fixing plate is fixedly connected to the bottom end of the Z-axis lifting platform.

[0011] As another improvement of the present application, multiple multi-core wires are fixedly connected in each control ring, and the number of multi-core wires is equal to the number of strain tiles connected to the control ring, and the multiple multi-core wires are electrically connected to the base layer, the first strain layer and the second strain layer.

[0012] As another improved supplement of the present application, the base layer is made of polyimide, and the base layer has good mechanical strength, elastic modulus and heat resistance, and the dielectric constant of the base layer is similar to that of the first strain layer and the second strain layer.

[0013] As another improved supplement of the present application, the first strain layer is made of an electrostrictive material, and the deformation of the first strain layer can reach more than 10%, and the second strain layer is made of a piezoelectric material.

[0014] As another improvement of the present application, the induction ring is made of piezoelectric material, and a fiber optic Bragg sensor is embedded in the induction ring, and the fiber optic Bragg sensor is arranged in a ring shape around the axis of the rotating shaft.

[0015] In summary, this application has the following beneficial effects:

[0016] 1. Reduce the height and volume of the four-axis motion platform; by embedding the T-axis rotating platform into the Y-axis moving platform, the rotation function can be achieved while reducing the height of the four-axis motion platform, so that the four-axis motion platform can be better used in high-precision high-end manufacturing fields. At the same time, the driving coil is used to directly drive the T-axis rotating platform to rotate, further reducing the volume of the four-axis motion platform.

[0017] 2. The dynamic response performance of the four-axis motion platform is improved; by setting a lower compensation component and an upper compensation component composed of strain pads on the rotating shaft, the deformation of the strain pads is used to compensate in real time for the balance and horizontal deviations of the platform during high-speed movement, thereby ensuring the movement accuracy of the platform under high dynamic conditions and improving the response speed and sensitivity.

[0018] 3. The active vibration suppression of the four-axis motion platform is realized; the piezoelectric material used in the strain pad has a piezoelectric effect, which can convert the mechanical vibration energy generated during the platform movement into electrical energy, thereby actively weakening the vibration. At the same time, the controller monitors the vibration state in real time and controls the deformation of the strain pad, which can actively suppress the vibration and improve the stability and reliability of the platform.

[0019] 4. Adaptive intelligent compensation control is realized; the platform stress state is monitored in real time through the first bearing and the second strain layer, and the monitoring data is transmitted to the controller. The controller automatically determines whether compensation adjustment is required based on the set deviation threshold and vibration threshold, and controls the corresponding strain pad to deform. The whole process has a high degree of automation, and can realize adaptive compensation control of balance, horizontal deviation and vibration.

[0020] 5. The adjustment accuracy and range of the motion platform are improved; the first strain layer uses electrostrictive material, the deformation can reach more than 10%, and a large adjustment can be achieved; the second strain layer uses piezoelectric material, the deformation is relatively small, and fine adjustment can be achieved. The combination of the two materials expands the compensation adjustment range of the platform while taking into account the adjustment accuracy.

[0021] 6. A highly integrated design has been achieved; the T-axis rotating platform is embedded in the Y-axis moving platform, realizing the embedded superposition of the two axes, reducing the overall height and occupied space, and making the platform structure more compact. At the same time, multiple strain tiles are distributed in a circular array, and the sensor and controller are integrated to achieve the integration of sensing, control and execution, and improve the integration of the system.

[0022] 7. Improve the service life of the motion platform; through adaptive compensation control of deviation and vibration, the impact of long-term operation on the accuracy and stability of the platform is reduced, and the service life of the platform is extended. The polyimide base layer used in the strain gauge has excellent mechanical strength and heat resistance, which enables the strain gauge to work stably for a long time under harsh working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a structural diagram of the T-axis rotating platform of this application;

[0024] Figure 2 This is a front view of the T-axis rotating platform of the present application;

[0025] Figure 3 For this application Figure 2 Middle AA section view;

[0026] Figure 4 It is the overall front view of this application;

[0027] Figure 5 For this application Figure 4 Middle BB section view;

[0028] Figure 6 A partial structural diagram of this application;

[0029] Figure 7 This is the appearance structure diagram of the T-axis rotating platform of this application;

[0030] Figure 8 This is an exploded view of the T-axis rotating platform of this application;

[0031] Fig. 9 Partial explosion of the T-axis rotating platform for this application Figure 2 ;

[0032] Fig.10 Partial explosion of the T-axis rotating platform for this application Figure 3 ;

[0033] Fig.11 Partial explosion of the T-axis rotating platform for this application Figure 4 ;

[0034] Fig.12 This is the overall appearance structure diagram of this application.

[0035] Description of the numbers in the figure:

[0036] 1. X-axis moving platform; 2. Y-axis moving platform; 3. Z-axis lifting platform; 4. T-axis rotating platform; 5. Rotating shaft; 6. Lower compensation component; 7. Upper compensation component; 8. Strain ring; 9. Control ring; 10. Strain tile; 11. Base layer; 12. First strain layer; 13. Second strain layer; 14. First bearing; 15. Second bearing; 16. Induction ring; 17. Z-axis fixing ring; 18. Z-axis fixing plate; 19. Permanent magnet; 20. Driving coil. DETAILED DESCRIPTION

[0037] Four implementation modes of the present application are described in detail below with reference to the accompanying drawings.

[0038] The first implementation method:

[0039] Figure 1-Figure 12 Shown.

[0040] A high dynamic response four-axis motion platform comprises an X-axis moving platform 1, the top of the X-axis moving platform 1 is slidably connected to a Y-axis moving platform 2, the Y-axis moving platform 2 is rotatably connected to a T-axis rotating platform 4, the top of the T-axis rotating platform 4 is fixedly connected to a Z-axis lifting platform 3, the top of the T-axis rotating platform 4 is flush with the top of the Y-axis moving platform 2, the T-axis rotating platform 4 comprises a rotating shaft 5 fixedly connected to the Y-axis moving platform 2, the T-axis rotating platform 4 comprises a Z-axis fixing ring 17, the outer end of the Z-axis fixing ring 17 is fixedly connected to a plurality of permanent magnets 19, the Y-axis moving platform 2 is fixedly connected to a driving coil 20 at positions corresponding to the permanent magnets 19, and the permanent magnets 19 are electrically connected to a controller.

[0041] The X-axis moving platform 1 is made of high-hardness material with high rigidity and high thermal stability. A linear motor and a grating ruler are installed on the X-axis moving platform 1 to achieve high-precision linear motion in the X-axis direction. The linear motor adopts an iron-coreless design to reduce the motion inertia and improve the dynamic response speed. The resolution of the grating ruler can reach nanometer level, ensuring high-precision positioning of the X-axis motion.

[0042] The Y-axis mobile platform 2 is slidably connected to the X-axis mobile platform 1 through a cross roller bearing to achieve movement in the Y-axis direction. A linear motor and a grating ruler are also installed on the Y-axis mobile platform 2 to achieve high-precision linear motion of the Y-axis. The X-axis and Y-axis are arranged orthogonally and connected by a precision coupling to ensure high-precision positioning in the XY plane.

[0043] The Z-axis lifting platform 3 is connected to the Y-axis moving platform 2 through a linear motor to achieve lifting movement in the Z-axis direction. Multiple air floating cushions are arranged on the Z-axis lifting platform 3 to achieve frictionless support by utilizing the restoring force of the air film, thereby improving the stability of the Z-axis movement.

[0044] The T-axis rotating platform 4 is embedded and fixed between the Y-axis moving platform 2 and the Z-axis lifting platform 3 to realize the rotational movement around the Z-axis. The core component of the T-axis rotating platform 4 is the rotating shaft 5, which is made of high-strength and high-rigidity titanium alloy material to ensure the rotation accuracy and stability.

[0045] The embedded design of the T-axis rotating platform 4 reduces the system height, lowers the center of gravity, and improves the rigidity and stability of the whole machine. The rotating shaft 5 is made of high-strength and high-rigidity materials to ensure the rotation accuracy and stability.

[0046] When in use, the controller controls the driving coil 20 to generate a magnetic field, thereby driving the plurality of permanent magnets 19 to drive the Z-axis fixing ring 17 to rotate, thereby realizing the rotation of the T-axis rotating platform 4 .

[0047] The second implementation method:

[0048] Figure 1-Figure 12 Shown.

[0049] The outer end of the rotating shaft 5 is fixedly connected with a lower compensation component 6 and an upper compensation component 7. The lower compensation component 6 and the upper compensation component 7 both include a strain ring 8. The top and bottom ends of the strain ring 8 are electrically connected to a control ring 9. The strain ring 8 is composed of a plurality of strain tiles 10 distributed in a circular array.

[0050] The strain shoe 10 includes a base layer 11, the outer end of the base layer 11 is fixedly connected to a first strain layer 12 and the inner end is fixedly connected to a second strain layer 13, multiple control rings 9 are electrically connected to the controller, the outer ends of the lower compensation component 6 and the upper compensation component 7 are respectively fixedly connected to a first bearing 14 and a second bearing 15, and an induction ring 16 is fixedly connected between the first bearing 14 and the second bearing 15.

[0051] The outer ends of the first bearing 14 and the second bearing 15 are fixedly connected to the Z-axis fixing ring 17 , the top of the Z-axis fixing ring 17 is fixedly connected to the Z-axis fixing plate 18 , and the top of the Z-axis fixing plate 18 is fixedly connected to the bottom end of the Z-axis lifting platform 3 .

[0052] Each control ring 9 is fixedly connected with a plurality of multi-core wires, and the number of the multi-core wires is equal to the number of strain tiles 10 connected to the control ring 9 . The plurality of multi-core wires are electrically connected to the base layer 11 , the first strain layer 12 and the second strain layer 13 .

[0053] The base layer 11 is made of polyimide and has good mechanical strength, elastic modulus and heat resistance. The dielectric constant of the base layer 11 is similar to that of the first strain layer 12 and the second strain layer 13 .

[0054] The first strain layer 12 is made of an electrostrictive material, and the deformation of the first strain layer 12 can reach more than 10%. The second strain layer 13 is made of a piezoelectric material.

[0055] The induction ring 16 is made of piezoelectric material, and a fiber Bragg sensor is embedded in the induction ring 16 . The fiber Bragg sensor is arranged in a ring shape around the axis of the rotating shaft 5 .

[0056] A lower compensation component 6 and an upper compensation component 7 are provided on the rotating shaft 5 to compensate for the axial and radial errors during the rotation process. The core of the compensation component is a strain ring 8, which is composed of a plurality of strain tiles 10 distributed in a circumferential array. Each strain tile 10 is composed of a three-layer structure of a base layer 11, a first strain layer 12 and a second strain layer 13. The first strain layer 12 is made of electrostrictive material, which will produce a large deformation under the action of voltage; the second strain layer 13 is made of piezoelectric material, and the deformation is relatively small, which can achieve fine control. By independently controlling the deformation of each strain tile 10, multi-degree-of-freedom precision compensation of the rotating shaft 5 can be achieved.

[0057] The top and bottom of the strain ring 8 are connected to a control ring 9, which has a built-in high-precision strain sensor to monitor the deformation state of the strain ring 8 in real time. At the same time, the control ring 9 is connected to an external control system through a flexible printed circuit, and the driving voltage of each strain tile 10 is accurately controlled according to the real-time feedback signal to achieve closed-loop compensation control.

[0058] In specific operation, when the T-axis rotating platform 4 rotates at high speed, the axial and radial errors of the rotating shaft 5 are detected by the strain sensor and fed back to the control system. The control system calculates the driving voltage of each strain shoe 10 according to the error signal, controls its deformation, and makes the lower compensation component 6 and the upper compensation component 7 produce a compensation displacement opposite to the error, thereby compensating the rotation error in real time and ensuring the high precision and stability of the T-axis rotation.

[0059] In addition, by introducing piezoelectric material into the strain tile 10 and utilizing the reverse piezoelectric effect of the piezoelectric material, the vibration energy during the rotation process can be converted into electrical energy, thereby achieving active suppression of vibration and improving the dynamic characteristics of the system.

[0060] The strain pads 10 are designed with a composite of electrostrictive materials and piezoelectric materials, achieving a combination of large-range compensation and fine control, thereby improving compensation accuracy. The strain pads 10 distributed in a circular array achieve multi-degree-of-freedom compensation and can effectively correct the axial and radial errors of the rotating shaft 5. The control ring 9 with integrated strain sensors achieves closed-loop control of the compensation process, thereby improving the real-time and reliability of compensation. The reverse piezoelectric effect of piezoelectric materials is utilized to achieve active suppression of vibration and improve the dynamic characteristics of the system.

[0061] A first bearing 14 and a second bearing 15 are respectively provided at the upper and lower ends of the rotating shaft 5 to support the rotational movement of the rotating shaft 5. The first bearing 14 is fixedly connected to the outer end of the lower compensation component 6, and the second bearing 15 is fixedly connected to the outer end of the upper compensation component 7. The two bearings are high-precision ceramic ball bearings, which have the advantages of high rigidity, low friction and long life, and ensure the accuracy and stability of the rotation of the rotating shaft 5.

[0062] An induction ring 16 is fixedly connected between the first bearing 14 and the second bearing 15, and is used to monitor the rotation state of the shaft 5 in real time. The induction ring 16 is made of piezoelectric material and is embedded with a fiber Bragg sensor. The fiber Bragg sensor is arranged in a ring shape around the axis of the shaft 5. When the shaft 5 produces axial or radial displacement, the induction ring 16 will produce corresponding strain, causing the change of the reflection wavelength of the fiber Bragg sensor. The displacement and speed of the shaft 5 can be accurately calculated through the demodulation algorithm.

[0063] A Z-axis fixing ring 17 is fixedly connected to the outer ends of the first bearing 14 and the second bearing 15, and a Z-axis fixing plate 18 is fixedly connected to the top of the Z-axis fixing ring 17. The top of the Z-axis fixing plate 18 is fixedly connected to the bottom of the Z-axis lifting platform 3, realizing the rigid connection between the T-axis rotating platform 4 and the Z-axis lifting platform 3. Through this connection structure, the T-axis rotating motion and the Z-axis lifting motion can be performed synchronously, expanding the degree of freedom of the motion platform.

[0064] A plurality of multi-core wires are fixedly connected in each control ring 9, and the number of wires is equal to the number of strain tiles 10 connected to the control ring 9. Each multi-core wire is electrically connected to the base layer 11, the first strain layer 12 and the second strain layer 13 of the strain tile 10, respectively, so as to realize independent control of each strain tile 10. The multi-core wire is made of a material with high flexibility and good shielding performance, which reduces the influence of the wire on the dynamic performance of the motion platform.

[0065] The base layer 11 of the strain tile 10 is made of polyimide material, which has excellent mechanical strength, elastic modulus and heat resistance, ensuring the stability of the strain tile 10 under high-frequency vibration and high-temperature environments. At the same time, the dielectric constant of the polyimide material is similar to the dielectric constant of the first strain layer 12 and the second strain layer 13, which reduces the electric field distortion caused by the dielectric constant mismatch and improves the control accuracy of the strain tile 10.

[0066] The first strain layer 12 of the strain tile 10 is made of electrostrictive material, which can produce more than 10% deformation under the action of the electric field, realizing a wide range of displacement compensation. The second strain layer 13 is made of piezoelectric material, with relatively small deformation, and is mainly used for fine control and vibration suppression. The combination of the two materials expands the control range and accuracy of the strain tile 10.

[0067] The outer end of the Z-axis fixed ring 17 is also fixedly connected with a T-axis power assembly, which is used to drive the T-axis rotating platform 4 to rotate around the Z-axis. The T-axis power assembly can be a torque motor or a servo motor, which transmits power to the Z-axis fixed ring 17 through a harmonic reducer to achieve T-axis rotation. The T-axis power assembly is fixedly connected to the Y-axis mobile platform 2 to ensure the reliability of power transmission.

[0068] The use of high-precision ceramic ball bearings improves the accuracy and stability of the rotation of the shaft 5 and extends the service life of the system. The induction ring 16 integrates a fiber optic Bragg sensor to achieve high-precision measurement of the displacement and speed of the shaft 5 and provide an accurate feedback signal for closed-loop control. The design of the Z-axis fixing ring 17 and the Z-axis fixing plate 18 realizes the synchronous movement of the T-axis rotating platform 4 and the Z-axis lifting platform 3, expanding the freedom and flexibility of the motion platform. The layered connection of the multi-core wire and the strain tile 10 realizes independent control of each strain tile 10 and improves the compensation accuracy and response speed. The use of the polyimide base layer 11 improves the mechanical and thermal stability of the strain tile 10 and ensures the reliability of the system under harsh working conditions. The composite use of electrostrictive materials and piezoelectric materials expands the compensation range and control accuracy of the strain tile 10. The fixed connection between the T-axis power assembly and the Y-axis moving platform 2 ensures the reliability of power transmission and improves the integration of the system.

[0069] This embodiment can be further expanded. For example, multiple types of sensors, such as temperature sensors, vibration sensors, etc., are integrated on the induction ring 16 to achieve comprehensive monitoring of the system status; a flexible coupling is set between the Z-axis fixing ring 17 and the Z-axis fixing plate 18 to reduce the impact of vibration on the Z-axis lifting motion; a high-precision encoder is integrated in the T-axis power assembly to achieve precise control of the T-axis rotation angle; high-speed optical fiber communication is used between the control ring 9 and the external control system to improve the speed and reliability of data transmission. These extended designs can further improve the performance and intelligence level of the motion platform and meet the needs of different application scenarios. Shape memory alloy materials are introduced into the strain pad 10, and temperature-driven adaptive compensation is achieved by using its superelasticity and bidirectional shape memory effect; a hollow cavity is set inside the rotating shaft 5 and filled with magnetorheological fluid. The liquid viscosity is controlled by adjusting the magnetic field strength to achieve controllable adjustment of the rotation damping; magnetic suspension bearings are integrated on the motion axes of the three linear platforms X, Y, and Z to achieve non-contact support for the entire system and further improve motion accuracy and stability. These extended designs can be flexibly selected and combined according to specific application requirements to obtain better system performance.

[0070] The third implementation method:

[0071] Figure 1-Figure 12 Shown.

[0072] A control method for a high dynamic response four-axis motion platform comprises the following steps:

[0073] S1, using the driving coil 20 through the controller to drive the permanent magnet 19 to drive the Z-axis fixed plate 18 and the Z-axis lifting platform 3 to rotate, monitoring the stress change in real time through the induction ring 16 and the multiple second strain layers 13, and transmitting the monitoring data to the controller;

[0074] S2, the controller determines whether the stress reaches the set deviation threshold or vibration threshold based on the monitoring data;

[0075] S3, when the stress reaches the deviation threshold, the controller calculates the angle deviation between the Z-axis fixing ring 17 and the axis of the rotating shaft 5, and determines the target first strain layer 12 and the second strain layer 13 that need to be adjusted and their adjustment amplitude and direction;

[0076] S4, the controller sends a control signal to the target first strain layer 12 and the second strain layer 13 to adjust their radial volumes, so that the Z-axis fixing ring 17 and the axis of the rotating shaft 5 rotate in the direction of coincidence until the deviation is less than the set threshold;

[0077] S5. When the stress reaches the vibration threshold, the controller determines the vibration amplitude and frequency, and controls the deformation of the plurality of first strain layers 12 and the second strain layers 13 accordingly to suppress or weaken the vibration;

[0078] S6. Repeat steps S1 to S5 to achieve real-time adaptive compensation control of the platform.

[0079] When the high dynamic response four-axis motion platform is working, the stress state of the T-axis rotating platform 4 is monitored in real time through the first bearing 14 and multiple second strain layers 13. The induction ring 16 integrated force sensor can accurately measure the axial and radial loads of the rotating shaft 5. The second strain layer 13 is made of piezoelectric material, which will generate electric charge when subjected to stress. The stress of the strain layer can be calculated by measuring the amount of charge. The monitoring data of the first bearing 14 and the second strain layer 13 are transmitted to the controller for analysis and processing.

[0080] The controller determines whether the T-axis rotating platform 4 is in an abnormal state according to the preset deviation threshold and vibration threshold. When the monitored stress exceeds the deviation threshold, it means that the balance or horizontality of the T-axis rotating platform 4 is deviated and compensation adjustment is required. The controller determines the target first strain layer 12 and the second strain layer 13 that need to be adjusted, as well as their adjustment amplitude and direction by calculating the angle deviation between the Z-axis fixing ring 17 and the axis of the rotating shaft 5.

[0081] The controller sends a control signal to the target strain layer, and uses the electrostrictive effect of the first strain layer 12 and the inverse piezoelectric effect of the second strain layer 13 to adjust their radial volumes. When the angle between the Z-axis fixing ring 17 and the axis of the rotating shaft 5 increases, the controller increases the radial volume of the first strain layer 12 and the second strain layer 13 in the direction of increasing the angle, and reduces the radial volume of the strain layer in the direction of decreasing the angle, so that the Z-axis fixing ring 17 produces a compensation displacement opposite to the deviation, and finally makes it coincide with the axis of the rotating shaft 5, completing the deviation compensation. The compensation process continues according to the real-time monitoring data until the deviation is less than the set threshold.

[0082] When the monitored stress exceeds the vibration threshold, it means that the T-axis rotating platform 4 has generated significant vibration and needs to be suppressed. The controller determines the main mode of vibration by analyzing the amplitude and frequency characteristics of the vibration signal. Then, the controller controls the deformation of the multiple first strain layers 12 and the second strain layers 13 accordingly, and uses the damping characteristics of the piezoelectric material to suppress the target vibration mode. By dynamically adjusting the deformation of the strain layer, the vibration of the T-axis rotating platform 4 can be effectively weakened or suppressed.

[0083] During the entire operation of the motion platform, the controller continuously performs the above-mentioned monitoring, judgment, compensation and suppression steps to achieve real-time adaptive control of the T-axis rotation platform 4. Through the closed-loop feedback mechanism, the motion platform can maintain high precision and stability under complex working conditions. In addition, when the motion platform needs to be adjusted with high precision on a micro scale, it can also be achieved by accurately controlling the deformation of the first strain layer 12 and the second strain layer 13.

[0084] The use of high-precision bearings and piezoelectric strain layers with integrated force sensors realizes real-time and high-precision monitoring of the stress state of the T-axis rotating platform 4, providing reliable feedback data for adaptive control. By calculating and compensating for the angle deviation between the Z-axis fixing ring 17 and the axis of the rotating shaft 5, automatic adjustment of the balance and horizontality deviations is realized, ensuring the rotation accuracy. The electrostrictive effect of the first strain layer 12 is used for large-scale adjustment, and the inverse piezoelectric effect of the second strain layer 13 is used for fine adjustment, expanding the compensation range and accuracy of the motion platform. Through the analysis of vibration signals and the dynamic control of the strain layer deformation, active vibration suppression is achieved, and the dynamic stability of the system is improved. The application of real-time closed-loop control strategy ensures the adaptability and reliability of the motion platform under complex working conditions.

[0085] This embodiment can be further expanded, for example, by introducing a self-learning algorithm in the controller to optimize the compensation and suppression control strategy based on historical working condition data; integrating other types of sensors such as temperature sensors and acceleration sensors in addition to the first bearing 14 and the second strain layer 13 to achieve comprehensive monitoring of the system status; connecting the motion platform to the cloud platform to achieve remote monitoring and predictive maintenance; and developing a human-computer interaction interface to facilitate users to set and adjust the parameters of the motion platform. These extended designs can further enhance the intelligence level and ease of use of the motion platform and expand its application areas.

[0086] The fourth implementation method:

[0087] Figure 1-Figure 12 Shown.

[0088] A controller for a high dynamic response four-axis motion platform, the controller is used to receive monitoring data from a force sensor and a second strain layer 13, determine whether the stress reaches a set deviation threshold or vibration threshold, and send a control signal to a target first strain layer 12 and a second strain layer 13 according to the determination result, adjust their radial volumes, and achieve deviation compensation and vibration suppression for the high dynamic response four-axis motion platform;

[0089] The controller includes a data acquisition module, a threshold judgment module, a compensation control module and a vibration suppression module, wherein the data acquisition module is used to collect and pre-process the monitoring data of the force sensor and the second strain layer 13, and has data filtering and feature extraction functions; the threshold judgment module is used to judge whether the high dynamic response four-axis motion platform is in a balance or horizontal deviation state, and whether it is in a vibration state according to the preset deviation threshold and vibration threshold, and has a self-learning function, and can dynamically adjust the deviation threshold and vibration threshold according to historical working condition data; the compensation control module is used to calculate the angle deviation between the Z-axis fixing ring 17 and the axis of the rotating shaft 5 in the deviation state, determine the target first strain layer 12 and the second strain layer 13 and their adjustment amplitude and direction, and generate a corresponding compensation control signal, using a PID control algorithm; the vibration suppression module is used to determine the main mode of vibration in the vibration state, and generate a corresponding suppression control signal, using an adaptive filtering control algorithm;

[0090] The controller uses a closed-loop control algorithm to continuously update the control signal based on real-time monitoring data until the high dynamic response four-axis motion platform restores balance or levelness, or the vibration amplitude is reduced to an acceptable range;

[0091] The controller is also used to adjust the posture of the high dynamic response four-axis motion platform with high precision on a micro scale by precisely controlling the deformation of the first strain layer 12 and the second strain layer 13;

[0092] The controller communicates with the force sensor and strain gauge layer via the CAN bus or EtherCAT bus.

[0093] During specific operation, the data acquisition module communicates with the built-in force sensor of the induction ring 16 and the multiple second strain layers 13 distributed on the strain tile 10 through the CAN bus or EtherCAT bus to collect force and strain data at a fixed frequency. The collected raw data is pre-processed by a filtering algorithm to remove high-frequency noise and random interference, extract effective characteristic signals, and convert them into physical quantities such as stress and strain.

[0094] The threshold judgment module receives the processed data and judges whether the motion platform is currently in a state of balance or horizontal deviation, and whether it is in a vibrating state, according to the preset deviation threshold and vibration threshold. The deviation threshold is used to evaluate the force balance of the motion platform. When the unbalanced torque exceeds the threshold, it is considered that the platform has a significant deviation; the vibration threshold is used to evaluate the vibration level of the motion platform. When the vibration amplitude exceeds the threshold, it is considered that the platform is in a vibrating state. The above two types of thresholds can be pre-set or obtained by self-learning by the threshold judgment module. By analyzing historical working condition data, the threshold judgment module can autonomously adjust the threshold size to adapt it to the current working condition.

[0095] When the balance or horizontality deviation is detected, the compensation control module starts to work. It first calculates the angle deviation between the Z-axis fixing ring 17 and the axis of the rotating shaft 5, that is, the degree of deviation between the actual position of the axis and the ideal position. Based on the deviation angle, the compensation control module determines the target first strain layer 12 and the second strain layer 13 that need to be adjusted, as well as the adjustment amplitude and direction of each strain layer. The adjustment principle is that for the strain layer in the deviation direction, the offset torque is generated by increasing its radial volume to make the Z-axis fixing ring 17 return to the ideal position; for the strain layer in the opposite direction of deviation, the deformation energy is released by reducing its radial volume to assist the platform to return to its position. The adjustment amplitude of each strain layer is determined by the PID control algorithm to achieve a smooth and fast compensation process.

[0096] When the vibration state is detected, the vibration suppression module starts to work. It identifies the main vibration mode, that is, the vibration component with the largest energy, by performing spectrum analysis on the vibration signal. For this component, the vibration suppression module calculates the corresponding suppression control signal, drives the strain layer to generate a force opposite to the vibration displacement and in the same direction as the vibration velocity, and actively suppresses the vibration. The magnitude of the suppression force is determined by the adaptive filtering control algorithm and can be adjusted in real time according to the change of the vibration state to achieve the best control effect.

[0097] During the entire control process, the controller uses a closed-loop control method to continuously obtain sensor feedback, compare it with the target value, and continuously update the control signal until the deviation or vibration is reduced to the allowable range. This real-time closed-loop control gives the motion platform adaptability, enabling it to maintain high precision and high stability under complex working conditions.

[0098] In addition, the controller also has a high-precision adjustment function. By accurately controlling the first strain layer 12 and the second strain layer 13, the position and posture of the motion platform can be adjusted at the micron level to meet the needs of ultra-precision motion control.

[0099] The controller can also be connected to sensors and actuators via wireless communication to meet the requirements of different application scenarios.

[0100] In view of current practical needs, the above-mentioned implementation mode adopted in this application is not limited to the scope of protection. Various changes made within the knowledge scope of technical personnel in this field without departing from the concept of this application still fall within the scope of protection of the present invention.

Claims

1. A four-axis motion platform, characterized in that: The invention comprises an X-axis moving platform (1), wherein the top of the X-axis moving platform (1) is slidably connected to a Y-axis moving platform (2), the Y-axis moving platform (2) is rotatably connected to a T-axis rotating platform (4), the top of the T-axis rotating platform (4) is fixedly connected to a Z-axis lifting platform (3), the top of the T-axis rotating platform (4) is flush with the top of the Y-axis moving platform (2), the T-axis rotating platform (4) comprises a rotating shaft (5) fixedly connected to the Y-axis moving platform (2), the T-axis rotating platform (4) comprises a Z-axis fixing ring (17), the outer end of the Z-axis fixing ring (17) is fixedly connected to a plurality of permanent magnets (19), the Y-axis moving platform (2) is fixedly connected to a driving coil (20) at positions corresponding to the permanent magnets (19), and the driving coil (20) is electrically connected to a controller; The outer end of the rotating shaft (5) is fixedly connected to a lower compensation component (6) and an upper compensation component (7), the lower compensation component (6) and the upper compensation component (7) both comprise a strain ring (8), the top and bottom ends of the strain ring (8) are electrically connected to a control ring (9), and the strain ring (8) is composed of a plurality of strain tiles (10) distributed in a circumferential array; The strain tile (10) comprises a base layer (11), the outer end of the base layer (11) is fixedly connected to a first strain layer (12), and the inner end is fixedly connected to a second strain layer (13); the plurality of control rings (9) are electrically connected to a controller; the outer ends of the lower compensation component (6) and the upper compensation component (7) are respectively fixedly connected to a first bearing (14) and a second bearing (15); an induction ring (16) is fixedly connected between the first bearing (14) and the second bearing (15); a plurality of multi-core wires are fixedly connected in each of the control rings (9), and the number of the multi-core wires is equal to the number of strain tiles (10) connected to the control ring (9); the plurality of multi-core wires are electrically connected to the base layer (11), the first strain layer (12), and the second strain layer (13); the first strain layer (12) is made of an electrostrictive material, and the deformation of the first strain layer (12) reaches more than 10%; and the second strain layer (13) is made of a piezoelectric material.

2. A four-axis motion platform according to claim 1, characterized in that: The outer ends of the first bearing (14) and the second bearing (15) are fixedly connected to a Z-axis fixing ring (17); a top end of the Z-axis fixing ring (17) is fixedly connected to a Z-axis fixing plate (18); and a top end of the Z-axis fixing plate (18) is fixedly connected to a bottom end of the Z-axis lifting platform (3).

3. A four-axis motion platform according to claim 1, characterized in that: The base layer (11) is made of polyimide, and the dielectric constant of the base layer (11) is similar to that of the first strain layer (12) and the second strain layer (13).

4. A four-axis motion platform according to claim 1, characterized in that: The induction ring (16) is made of piezoelectric material, and a fiber optic Bragg sensor is embedded in the induction ring (16), wherein the fiber optic Bragg sensor is arranged in a ring shape around the axis of the rotating shaft (5).

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