CN116146654A

CN116146654A - Vibration damping platform, workpiece table with vibration damping platform and vibration damping platform control method

Info

Publication number: CN116146654A
Application number: CN202310008471.6A
Authority: CN
Inventors: 高建祥
Original assignee: Hefei Yuwei Semiconductor Technology Co ltd
Current assignee: Hefei Yuwei Semiconductor Technology Co ltd
Priority date: 2023-01-04
Filing date: 2023-01-04
Publication date: 2023-05-23

Abstract

The invention belongs to the technical field of vibration isolation devices, and discloses a vibration reduction platform, a workpiece table with the vibration reduction platform and a vibration reduction platform control method, wherein the vibration reduction platform comprises a lower bottom plate, an upper top plate, a plurality of air bearing, a sensor assembly and a plurality of voice coil motors; the upper top plate supports a load; the air bearing is arranged between the lower bottom plate and the upper top plate and is used for floatingly supporting the upper top plate; the sensor assembly is arranged between the lower bottom plate and the upper top plate, and detects the speed value or the displacement value of the lower bottom plate and/or the upper top plate; the voice coil motor is arranged between the lower bottom plate and the upper top plate, the voice coil motor is in communication connection with the sensor assembly, and the rotor end of the voice coil motor can apply acting force or acting torque to the upper top plate so as to keep the upper top plate stationary. The vibration damping platform can effectively inhibit motion impact and better vibration isolation, keep balance and stability in the interior world, and the workpiece platform with the vibration damping platform has better motion precision control on a load, and the vibration damping platform control method can realize vibration isolation control and motion self-balancing control.

Description

Vibration damping platform, workpiece table with vibration damping platform and vibration damping platform control method

Technical Field

The invention relates to the technical field of vibration isolation devices, in particular to a vibration reduction platform, a workpiece table with the vibration reduction platform and a vibration reduction platform control method.

Background

With the development of semiconductor manufacturing processes, the precision of the semiconductor manufacturing equipment is higher and the vibration reduction requirement of the semiconductor manufacturing equipment is higher, because the electromechanical system and the optical system of the semiconductor manufacturing equipment need to realize the motion precision control of nanometer level, the internal world of the semiconductor manufacturing equipment needs to be in an absolute static state, and all interference factors such as vibration from the external environment need to be effectively isolated. Meanwhile, along with the improvement of the productivity of the semiconductor manufacturing process, the movement speed and the acceleration of the semiconductor manufacturing equipment are also accelerated extremely, the acceleration of the workpiece table can reach 20m/s2-100m/s2, and a motor for driving the workpiece table can generate huge movement counter force to act on the inside world. Without an efficient vibration damping balancing device, the inside world of the semiconductor manufacturing equipment would be under severe jolts and the electromechanical and optical systems would not be able to accurately position the work.

Most of the existing semiconductor manufacturing equipment uses viscoelastic vibration isolation elements, such as rubber materials, springs, hydraulic oil and the like, to reduce the rigidity of the system so as to improve damping for vibration isolation. However, these viscoelastic vibration insulating members are mainly used to insulate external environmental vibrations, and cannot effectively suppress motion shocks from inside the semiconductor manufacturing apparatus.

Disclosure of Invention

A first object of the present invention is to provide a vibration damping platform capable of effectively suppressing a motion impact from inside a semiconductor manufacturing apparatus, maintaining balance stability of the inside world, and achieving vibration isolation with higher accuracy.

To achieve the purpose, the invention adopts the following technical scheme:

there is provided a vibration damping platform comprising:

a lower base plate connectable to a support structure;

an upper top plate for supporting a load;

the air bearing is arranged between the lower bottom plate and the upper top plate and is used for floatingly supporting the upper top plate;

the sensor assembly is arranged between the lower bottom plate and the upper top plate and is used for detecting a speed value or a displacement value of the lower bottom plate and/or the upper top plate;

the voice coil motors are arranged between the lower bottom plate and the upper top plate, the voice coil motors are in communication connection with the sensor assembly, and the rotor ends of the voice coil motors can apply acting force or acting moment to the upper top plate so as to enable the upper top plate to keep static.

As a preferred structure of the present invention, the sensor assembly includes:

The absolute speed sensor is fixedly connected to the upper top plate and is used for detecting the absolute speed value of the upper top plate;

the foundation speed sensor is fixedly connected to the lower base plate and is used for detecting the speed value of the lower base plate;

the displacement sensor is fixedly connected to the lower bottom plate and is used for detecting a displacement value of the upper top plate relative to the lower bottom plate.

As a preferable structure of the present invention, the voice coil motor includes at least one X-direction voice coil motor for driving the upper top plate to move in the X-direction, at least one Y-direction voice coil motor for driving the upper top plate to move in the Y-direction, and at least one Z-direction voice coil motor for driving the upper top plate to move in the Z-direction.

As a preferable configuration of the present invention, the air bearing includes:

the base is fixedly connected to the lower bottom plate;

the upper floating plate is fixedly connected to the upper top plate;

The air supporting piece, the air supporting piece connect in on the base, be provided with a plurality of orifices on the air supporting piece, the one end intercommunication outside air supply of orifice, the other end orientation go up the kickboard, the air supporting piece with have the floating clearance between the kickboard, outside air supply is used for providing the malleation gas so that the air supporting piece floating support go up the kickboard.

As a preferable structure of the invention, the vibration reduction platform further comprises a limiting assembly, the limiting assembly comprises a plurality of limiting pieces, the limiting pieces comprise limiting rods and limiting seats, the limiting seats are fixedly connected to the lower bottom plate, the limiting rods are fixedly connected to the upper top plate, the limiting rods are slidably arranged in the limiting seats, and the limiting pieces are used for limiting the distance between the upper top plate and the lower bottom plate.

The second object of the invention is to provide a workpiece table with a vibration reduction platform, which can realize effective isolation between the outside world and the inside world, has good vibration isolation effect and better control on the motion precision of a load.

To achieve the purpose, the invention adopts the following technical scheme:

there is provided a work piece table with a vibration reduction platform, including the vibration reduction platform as described above, the work piece table with a vibration reduction platform further comprising:

The support frame is used for supporting the lower bottom plate, and the lower bottom plate is detachably connected to the support frame;

the load platform is detachably connected to the upper top plate and is arranged on one side, far away from the lower bottom plate, of the upper top plate;

the motion assembly is arranged on the load platform and used for driving a load to move, the motion assembly comprises a motion controller, the motion controller is used for controlling the motion speed of the motion assembly, and the motion controller is in communication connection with the voice coil motor.

As a preferable structure of the present invention, the moving assembly includes an X-axis moving structure fixedly connected to the load platform, and a Y-axis moving structure slidably connected to the X-axis moving structure, and the load is slidably connected to the Y-axis moving structure.

A third object of the present invention is to provide a vibration damping platform control method capable of performing vibration damping control and motion self-balancing control on a vibration damping platform of a work table, so that the inside world is always kept still to improve motion accuracy control of the work table.

To achieve the purpose, the invention adopts the following technical scheme:

the vibration reduction platform control method is used for controlling the workpiece platform with the vibration reduction platform, and comprises the following steps of:

the sensor assembly detects and obtains a speed value and/or a displacement value of the lower bottom plate and/or the upper top plate, and converts the speed value and the displacement value into a first force value;

the motion controller detects a motion counter force and/or a motion counter force moment applied to the upper top plate by the motion assembly and converts the motion counter force and/or the motion counter force moment into a second force value;

and weighting and distributing the first force value and the second force value to a plurality of voice coil motors, and controlling the rotor ends of the voice coil motors to drive the upper top plate respectively so as to keep the upper top plate stationary.

As a preferable configuration of the present invention, the sensor assembly detects and obtains a velocity value and/or a displacement value of the lower plate and/or the upper plate, specifically including: an absolute speed sensor detects speed values of 6 degrees of freedom of the upper top plate, a foundation speed sensor detects speed values of 3 degrees of freedom of the lower bottom plate, and a displacement sensor detects displacement values of 3 degrees of freedom of the upper top plate relative to the lower bottom plate.

As a preferable configuration of the present invention, the motion controller detects a motion reaction force and/or a motion reaction force moment applied to the upper top plate by the motion assembly, and specifically includes: and calculating X-direction movement counter force and/or Y-direction movement counter force and/or Z-direction movement counter force and/or Rx-direction movement counter force moment and/or Ry-direction movement counter force moment and/or Rz-direction movement counter force moment applied to the upper top plate by the movement assembly according to the acceleration curve and the position curve output by the movement controller.

The invention has the beneficial effects that:

the vibration reduction platform provided by the invention adopts the air bearing to support the upper top plate, and the air bearing generates viscous damping through air flow, so that the damping force of the system can be improved, and the vibration isolation effect is improved; the air bearing has no rigidity in the horizontal direction, low-frequency interference is not introduced, and the low-frequency vibration isolation effect in the horizontal direction can be remarkably improved; the upper top plate (the inner world) and the lower bottom plate (the outer world) are connected by one or more air bearing instead of the traditional spring or the air bag to serve as a supporting device, so that vertical support and vibration isolation are carried out, and the inner world and the outer world are isolated. The air bearing has no rigidity in the horizontal direction, the air bearing can reduce the position accuracy of an upper top plate supported by the air bearing in the horizontal direction as a vibration reduction device, and more accurate control on the horizontal direction of the upper top plate needs to be added, so that the relative displacement of the upper top plate and a lower bottom plate needs to be accurately measured, and the measurement result is fed back to a control module of the vibration reduction platform.

The vibration reduction platform detects the speed value or the acceleration value or the displacement value of the lower bottom plate and/or the upper top plate in real time through the sensor assembly, controls the output of the voice coil motors in real time through self-balancing control, can form a ceiling damping mechanism to inhibit the vibration of the upper top plate (the inside world), and can balance the acceleration impact, the gravity center deviation and the like applied to the upper top plate in the high-speed motion process of a load (the inside of the semiconductor manufacturing equipment) through self-balancing control so as to keep the balance and the stability of the upper top plate (the inside world); and, the displacement closed-loop control of the upper top plate through the voice coil motor keeps the position of the upper top plate (the inside world) stable. The air bearing has compact size, can obviously reduce vertical height, has small volume and ensures that the corresponding performance of the vibration reduction platform is faster.

The workpiece table with the vibration reduction platform comprises the vibration reduction platform, when a motion assembly drives a load to move at a high speed, the vibration reduction platform adopts motion self-balancing control, and the motion acceleration of the load platform and the gravity center variation in motion coordinates are obtained in real time through data communication, so that a plurality of voice coil motors are controlled to synchronously apply acting force or acting moment to an upper top plate; meanwhile, vibration isolation control is adopted by the vibration reduction platform, and the speed value or the displacement value of the lower bottom plate and/or the upper top plate is measured in real time through the sensor assembly, so that the plurality of voice coil motors are controlled to synchronously apply acting force to the upper top plate, a canopy damping mechanism and a motion feedforward self-balancing mechanism are formed, the stability of the inside world is further guaranteed, the vibration isolation effect is good, and the motion accuracy of a load is better controlled.

The vibration damping platform control method provided by the invention is used for controlling the workpiece platform with the vibration damping platform, and converting the detection value of the sensor assembly and the acceleration curve and the position curve output by the motion controller into the first force value and the second force value to control the mover ends of the voice coil motors to respectively drive the upper top plate so as to keep the upper top plate stationary, thereby realizing vibration damping control and motion self-balancing control on the workpiece platform, and ensuring that the inside world is kept stationary all the time so as to improve the motion precision control of the workpiece platform on the load.

Drawings

FIG. 1 is a schematic view of a vibration damping platform according to an embodiment of the present invention;

FIG. 2 is a schematic view of a portion of a vibration damping platform according to a first embodiment of the present invention;

FIG. 3 is a schematic diagram of a portion of a vibration damping platform according to a first embodiment of the present invention;

fig. 4 is a schematic structural diagram of an air bearing according to a first embodiment of the present invention;

FIG. 5 is a schematic view of a workpiece stage with a vibration reduction platform according to a second embodiment of the present invention;

fig. 6 is a schematic diagram of a vibration damping platform control method according to a third embodiment of the present invention.

In the figure:

1. a lower base plate; 2. an upper top plate; 3. an air bearing; 31. a base; 32. an upper floating plate; 33. an air floatation block; 331. an orifice; 34. an air floatation gap; 4. a sensor assembly; 41. an absolute speed sensor; 42. a foundation speed sensor; 43. a displacement sensor; 50. a mover end; 51. an X-direction voice coil motor; 52. a Y-direction voice coil motor; 53. a Z-direction voice coil motor; 6. a limit component; 61. a limiting piece; 611. a limit rod; 612. a limit seat; 7. a control module;

100. A support frame; 200. a load platform; 300. a motion assembly; 301. an X-axis motion structure; 302. a Y-axis motion structure; 400. and (3) loading.

Detailed Description

The invention is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting thereof. It should be further noted that, for convenience of description, only some, but not all of the structures related to the present invention are shown in the drawings.

In the description of the present invention, unless explicitly stated and limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

In the present invention, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "left", "right", and the like are orientation or positional relationships based on those shown in the drawings, merely for convenience of description and simplicity of operation, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the invention. Furthermore, the terms "first," "second," and the like, are used merely for distinguishing between descriptions and not for distinguishing between them.

Most of the existing semiconductor manufacturing equipment uses viscoelastic vibration isolation elements, such as rubber materials, springs, hydraulic oil and the like, to reduce the rigidity of the system so as to improve damping for vibration isolation. However, these viscoelastic vibration insulating members are mainly used to insulate external environmental vibrations, and cannot effectively suppress motion shocks from inside the semiconductor manufacturing apparatus. In order to solve the problems, the embodiment of the invention provides a vibration reduction platform, a workpiece platform with the vibration reduction platform and a vibration reduction platform control method.

Example 1

As shown in fig. 1 to 5, an embodiment of the present invention provides a vibration damping platform, which includes a lower base plate 1, an upper top plate 2, a plurality of air bearing bearings 3, a sensor assembly 4, and a plurality of voice coil motors. The vibration reduction platform is provided with a control module 7, and the control module 7 can be arranged on the lower bottom plate 1 or independently arranged outside the vibration reduction platform. The lower plate 1 can be connected to a support structure; the upper top plate 2 is used for supporting a load 400; the air bearing 3 is arranged between the bottom plate 1 and the upper top plate 2, and the air bearing 3 is used for floatingly supporting the upper top plate 2; the air bearing 3 generates viscous damping through gas flow, so that the damping force of the system can be improved, and the vibration isolation effect is improved. The air bearing 3 has no rigidity in the horizontal direction, low-frequency interference is not introduced, and the low-frequency vibration isolation effect in the horizontal direction can be obviously improved. The vibration reduction platform provided by the embodiment of the invention is provided with 4 air bearing bearings 3 which are respectively arranged at four corners of the lower bottom plate 1, so that the upper top plate 2 can be stably supported.

The sensor assembly 4 is arranged between the lower bottom plate 1 and the upper top plate 2, and the sensor assembly 4 is used for detecting a speed value or an acceleration value or a displacement value of the lower bottom plate 1 and/or the upper top plate 2; specifically, the selection may be made according to the processing requirements of the load 400. The voice coil motor sets up between lower plate 1 and upper plate 2, and voice coil motor passes through control module 7 communication connection sensor assembly 4, and voice coil motor's active cell end 50 can apply effort or action moment to upper plate 2 so that upper plate 2 remains stationary. The voice coil motor drives the rotor end 50 arranged on the upper top plate 2 in real time according to the measured value of the sensor assembly 4, so that closed-loop control of the upper top plate 2 is realized. The voice coil motor is also called as Lorentz force motor, and has high response speed and large force value. The data transmission between the control module 7 and the sensor assembly 4, and the control manner of the voice coil motor are known in the art, and the embodiments of the present invention are not described herein.

According to the vibration reduction platform provided by the embodiment of the invention, one or more air bearing(s) 3 are used for replacing a traditional spring or an air bag to serve as a supporting device, and are connected with the upper top plate 2 (the internal world) and the lower bottom plate 1 (the external world) to vertically support and isolate vibration, so that the isolation between the internal world and the external world is realized. The air bearing 3 has no rigidity in the horizontal direction, the air bearing 3 as a vibration damping device can reduce the position accuracy of the upper top plate 2 supported by the air bearing 3 in the horizontal direction, and more accurate control on the horizontal direction of the upper top plate 2 needs to be increased, so that accurate measurement on the relative displacement of the upper top plate 2 and the lower bottom plate 1 is needed, and the measurement result is fed back to a control module of the vibration damping platform.

The vibration reduction platform detects the speed value or the acceleration value or the displacement value of the lower bottom plate 1 and/or the upper top plate 2 in real time through the sensor component 4, controls the output of the voice coil motors in real time through self-balancing control, can form a ceiling damping mechanism to inhibit the vibration of the upper top plate 2 (the inside world), and balances the acceleration impact, the gravity center deviation and the like applied to the upper top plate 2 in the high-speed movement process of the load 400 (the inside of the semiconductor manufacturing equipment) so as to keep the balance and the stability of the upper top plate 2 (the inside world); and, the displacement closed-loop control of the upper top plate 2 by the voice coil motor keeps the upper top plate 2 (inside world) position stable. The air bearing 3 has compact size, can obviously reduce the vertical height, has small volume and ensures that the corresponding performance of the vibration reduction platform is faster.

Preferably, the sensor assembly 4 comprises at least one absolute speed sensor 41, at least one ground speed sensor 42 and at least one displacement sensor 43. The absolute speed sensor 41 is fixedly connected to the upper top plate 2, and the absolute speed sensor 41 is used for detecting the absolute speed value of the upper top plate 2; the foundation speed sensor 42 is fixedly connected to the lower base plate 1, and the foundation speed sensor 42 is used for detecting the speed value of the lower base plate 1; the displacement sensor 43 is fixedly connected to the lower base plate 1, and the displacement sensor 43 is used for detecting a displacement value of the upper top plate 2 relative to the lower base plate 1.

Optionally, the vibration damping platform of the embodiment of the present invention is provided with 3

absolute speed sensors

41,3 and 41, where each absolute speed sensor 41 has two detection capabilities in two directions, and the 3 absolute speed sensors 41 have 3 detection capabilities in Z, 2X, and 1Y directions in total. The vibration reduction platform of the embodiment of the invention is provided with 1 foundation speed sensor 42 with triaxial detection capability, wherein the foundation speed sensor 42 is a triaxial sensor, can measure the speed of the lower base plate 1 in the X direction, the Y direction and the Z direction in 3 orthogonal directions, and transmits the measured value to the control module 7 in real time; the ground speed sensor 42 measures the vibration of the external environment and feeds forward the controller to control the voice coil motor for higher accuracy vibration isolation. The vibration damping platform of the embodiment of the invention is provided with 3 displacement sensors 43, wherein the displacement sensors 43 consist of a sensor 431 and a sensor bracket 432; the sensor bracket 432 is fixed to the lower plate 1 by bolts, and the sensor member 431 is connected to the sensor bracket 432 by self-threads. A certain gap is kept between the sensing member 431 and the upper top plate 2, and displacement changes of the upper top plate 2 relative to the lower bottom plate 1 can be accurately detected in real time through 3 points.

Specifically, the absolute speed sensor 41 can measure the absolute speed of the upper top plate 2 in real time and synchronously feed back to the control module 7, forming a canopy damping mechanism to suppress the internal world vibration. The displacement sensor 43 can measure the position change of the upper top plate 2 relative to the lower bottom plate 1 in real time, synchronously feed back to the control module 7, and compensate through the corresponding voice coil motor to form a displacement ring feedback, so that the position of the inner world is kept stable. The ground speed sensor 42 mounted on the lower plate 1 or the ground can measure the vibration of the external environment and feed forward to the control module 7 to control the voice coil motor, achieving higher accuracy vibration isolation.

Preferably, the voice coil motor comprises at least one X-direction voice coil motor 51, at least one Y-direction voice coil motor 52 and at least one Z-direction voice coil motor 53, wherein the X-direction voice coil motor 51 is used for driving the X-direction motion of the upper top plate 2, the Y-direction voice coil motor 52 is used for driving the Y-direction motion of the upper top plate 2, and the Z-direction voice coil motor 53 is used for driving the Z-direction motion of the upper top plate 2.

Specifically, the vibration damping platform of the embodiment of the invention is provided with 2X-direction voice coil motors 51 in the X direction and 2Y-direction voice coil motors 52 in the Y direction, so that vibration of the upper top plate 2 in the X direction, the Y direction and the Rz direction can be respectively inhibited; the 4Z-direction voice coil motors 53 are arranged in the Z-direction and can be used to suppress vibrations of the upper top plate 2 in the Rx-direction, ry-direction, and Z-direction degrees of freedom. The stator end of the X-direction voice coil motor 51, the stator end of the Y-direction voice coil motor 52 and the stator end of the Z-direction voice coil motor 53 are fixed on the lower plate 1 by bolts, and the mover end 50 of the X-direction voice coil motor 51, the mover end 50 of the Y-direction voice coil motor 52 and the mover end 50 of the Z-direction voice coil motor 53 are fixed on the upper plate 2 by bolts. When the semiconductor manufacturing equipment such as the load 400 supported by the upper top plate 2 moves horizontally at a high speed, the vibration damping platform can perform self-balancing control according to the real-time movement acceleration of the load 400, and the 2X-direction voice coil motors 51 and 2Y-direction voice coil motors 52 horizontally synchronously generate acting forces with the same and opposite directions as the movement inertia force and the inertia moment of the load 400, so that the force balance and the moment balance of the internal world are realized, the movement impact is balanced, and the stability of the internal world is kept; meanwhile, according to the real-time motion coordinates of the load 400, the gravity center variation is converted into a force value through calculation, 4Z-direction voice coil motors 53 are driven in real time, so that moment balance in the vertical direction of the internal world is realized, and the internal world is kept stable.

Preferably, the air bearing 3 comprises a base 31, an upper floating plate 32 and an air floating block 33. The base 31 is fixedly connected to the lower base plate 1; the upper floating plate 32 is fixedly connected to the upper top plate 2; the air supporting piece 33 is connected to the base 31, a plurality of orifices 331 are arranged on the air supporting piece 33, the orifices 331 extend from the inside of the air supporting piece 33 to the upper surface of the air supporting piece 33, one end of each orifice 331 is communicated with an external air source, and the other end of each orifice 331 faces the upper floating plate 32. A floating gap 34 is provided between the air bearing 33 and the upper floating plate 32, and an external air source is used for providing positive pressure air to enable the air bearing 33 to floatingly support the upper floating plate 32. When the orifice 331 is filled with positive pressure gas, the positive pressure gas diffuses into the atmosphere through the air floating gap 34 between the upper floating plate 32 and the air floating block 33; the flowing positive pressure gas forms a pressure difference under the gas lubrication effect, thereby supporting the upper floating plate 32, and an air floating gap 34 of about several tens micrometers is formed between the upper floating plate 32 and the air floating block 33. The support structure with viscous damping generated by the gas flow can improve the damping force of the system, does not introduce low-frequency interference, and can remarkably improve the low-frequency vibration isolation effect in the horizontal direction.

As a preferred scheme, the vibration damping platform further comprises a limiting assembly 6, the limiting assembly 6 comprises a plurality of limiting pieces 61, the limiting pieces 61 comprise limiting rods 611 and limiting seats 612, the limiting seats 612 are fixedly connected to the lower base plate 1, the limiting rods 611 are fixedly connected to the upper top plate 2, the limiting rods 611 are slidably arranged in the limiting seats 612, and the limiting pieces 61 are used for limiting the distance between the upper top plate 2 and the lower base plate 1. A limiting groove is formed in the limiting seat 612, and the limiting rod 611 can freely move in the limiting groove; when the movement distance exceeds the set value, the limit rod 611 collides with the limit seat 612 and is restricted from moving, thereby restricting the movement distance of the upper plate 2 with respect to the lower plate 1. The vibration reduction platform is provided with 4 limiting assemblies 6 which are respectively arranged at four corners of the vibration reduction platform, and the limiting members 61 interact with each other, so that the distance between the upper top plate 2 and the lower bottom plate 1 can be limited in the X direction, the Y direction and the Z direction in 3 directions, the safety and the reliability of the vibration reduction platform are improved, and the damage of the air bearing 3 and the voice coil motor is prevented.

Example two

The second embodiment of the present invention provides a workpiece stage with a vibration reduction platform, where the workpiece stage with a vibration reduction platform includes the vibration reduction platform in the first embodiment, and the workpiece stage further includes a support frame 100, a load platform 200, and a motion assembly 300. The support frame 100 is used for supporting the lower base plate 1, and the lower base plate 1 is detachably connected to the support frame 100 through bolts; the load platform 200 is detachably connected to the upper top plate 2 and is arranged on one side of the upper top plate 2 away from the lower bottom plate 1; preferably, the loading platform 200 is a marble platform, which has advantages of high precision, rust resistance, acid and alkali resistance, non-magnetization, non-deformation, good wear resistance, etc., and can be kept stable under heavy load and general temperature to improve the movement precision of the movement assembly 300.

The motion assembly 300 is disposed on the load platform 200, the motion assembly 300 is used for driving the load 400 to move, the motion assembly 300 comprises a motion controller (not shown in the figure), the motion controller is used for controlling the motion speed of the motion assembly 300, and the motion controller is communicatively connected with a plurality of voice coil motors. The vibration reduction platform supports the load platform 200, the motion assembly 300 and the load 400 through the air bearing 3, so that the load platform 200, the motion assembly 300 and the load 400 are suspended at the upper part of the support frame 100; the vibration reduction platform, the load platform 200, the motion assembly 300 and the load 400 form an internal world, are isolated from the vibration environments of the support frame 100 and the external world, realize effective isolation of the internal world and the external world, have good vibration isolation effect, and have better motion precision control on the load 400.

When the motion assembly 300 drives the load 400 to move at a high speed, the workpiece platform with the vibration reduction platform adopts motion self-balancing control, and the motion acceleration of the load platform 200 and the gravity center variation in motion coordinates are obtained in real time through data communication with the sensor assembly 4, so that the voice coil motors are controlled to synchronously apply acting force or acting moment to the upper top plate 2; meanwhile, vibration isolation control is adopted in the vibration damping platform, and the speed value or the displacement value of the lower bottom plate 1 and/or the upper top plate 2 is measured in real time through the sensor assembly 4 so as to control the voice coil motors to synchronously apply acting force to the upper top plate 2. A canopy damping mechanism and a motion feedforward self-balancing mechanism are formed, so that the stability of the inside world is maintained.

Specifically, the motion assembly 300 includes an X-axis motion structure 301 and a Y-axis motion structure 302, the X-axis motion structure 301 being fixedly coupled to the load platform 200, the Y-axis motion structure 302 being slidably coupled to the X-axis motion structure 301, and the load 400 being slidably coupled to the Y-axis motion structure 302. The specific mechanisms and motion principles of the X-axis motion structure 301 and the Y-axis motion structure 302 are prior art in the art, and the second embodiment of the present invention is not limited herein.

The workpiece table with the vibration reduction platform provided by the second embodiment of the invention realizes two functions of vibration reduction and motion feedforward self-balancing of the load 400 through the vibration reduction platform, and the specific implementation process is as follows:

1. vibration damping function

The absolute speed sensor 41 of the vibration reduction platform mounted on the upper top plate 2 detects the absolute speed of the upper top plate 2 in real time, the control module 7 decouples the calculated measured data, weights the measured data and drives the voice coil motors in multiple directions to form a canopy damping to restrain the vibration of the inside world. Conventional damping materials such as rubber, air bags, etc. have damping coefficients proportional to the relative speeds of the upper plate 2 and the lower plate 1, and are called zenithal damping since the force of the voice coil motor (active damping) is proportional to the absolute speed of the upper plate 2 as if a damping with the sky was applied to the upper plate 2. And obtaining a damping coefficient Csky through calculation, wherein the damping coefficient Csky is used for weighting calculation of force values of the voice coil motors in multiple directions. The 8 voice coil motors are in decoupling control, so that vibration of the upper top plate 2 of the vibration reduction platform, the load platform 200, the motion assembly 300 and the load 400 in six degrees of freedom in X direction, Y direction, Z direction, rx direction, ry direction and Rz direction can be restrained and balanced.

The foundation speed sensor 42 of the vibration reduction platform mounted on the lower base plate 1 can measure the speed of the lower base plate 1 in the X direction, the Y direction and the Z direction, the foundation speed sensor 42 transmits the measured speed value to the control module 7, the control module 7 applies decoupling weighting to a plurality of voice coil motors respectively according to the measured speed value, and feedforward control of the foundation vibration speed is realized so as to inhibit vibration of the upper top plate 2 of the vibration reduction platform, namely the internal world.

The displacement sensor 43 of the vibration reduction platform mounted on the lower bottom plate 1 can measure the displacement change of the upper top plate 2 relative to the lower bottom plate 1, the displacement sensor 43 transmits the measured position value to the control module 7, and the control module 7 respectively applies the decoupling weighting to the voice coil motors by multiplying the coefficient according to the measured value fed back by the displacement sensor 43 so as to keep the horizontal position of the upper top plate 2 stable;

2. motion feedforward self-balancing function

The motion feedforward self-balancing function of the workpiece table comprises: acceleration is self-balancing and position is self-balancing. Acceleration self-balancing focuses on the force balance of the workpiece table in the horizontal direction, and position self-balancing focuses on the force balance of the workpiece table in the vertical direction.

When the moving assembly 300 of the inside world works in the X direction, the moving assembly 300 drives the load 400 to move at high acceleration in the X direction, and generates a reaction force in the X direction to the upper top plate 2, so that the inside world has a movement trend opposite to the acceleration direction of the load 400. The motion controller drives the load 400 to act through the motion assembly 300 and simultaneously sends an acceleration curve to the control module 7, and the control module 7 drives the X-direction voice coil motor 51 to synchronously generate an acting force with the same amplitude and the same direction as the acceleration direction of the load 400, and the acting force acts on the upper top plate 2 of the vibration reduction platform, namely the internal world, so that the internal world force is balanced; meanwhile, the control module 7 drives the two X-direction voice coil motors 51 to output acting forces with different magnitudes according to specific motion path decoupling calculation so as to realize moment balance of the internal world, and the internal world always keeps a static state in a state of force balance and moment balance.

When the motion assembly 300 of the inside world works in the Y direction, the motion assembly 300 drives the load 400 to perform high acceleration motion in the Y direction, and generates a reaction force in the Y direction to the upper top plate 2, so that the inside world has a motion trend opposite to the acceleration direction of the load 400. The motion controller drives the load 400 to act through the motion assembly 300 and simultaneously sends an acceleration curve to the control module 7, and the control module 7 drives the Y-direction voice coil motor 52 to synchronously generate an acting force with the same amplitude and the same direction as the acceleration direction of the load 400, and the acting force acts on the upper top plate 2 of the vibration reduction platform, namely the internal world, so that the internal world force is balanced; meanwhile, the control module 7 drives the two Y-direction voice coil motors 52 to output acting forces with different magnitudes according to specific motion path decoupling calculation so as to realize moment balance of the internal world, and the internal world always keeps a static state in a state of force balance and moment balance.

When the motion assembly 300 in the internal world works simultaneously along the X direction and the Y direction, the motion controller sends an acceleration curve to the control module 7 when the motion assembly 300 drives the load 400 to act, and the control module 7 drives the X-direction voice coil motor 51 and the Y-direction voice coil motor 52 of the vibration reduction platform to synchronously generate corresponding acting force to act on the internal world, so that the internal world force is balanced; meanwhile, the control module 7 drives the two X-direction voice coil motors 51 and the two Y-direction voice coil motors 52 to output different forces according to specific motion path decoupling calculation so as to realize force balance and moment balance of the internal world, and the internal world always keeps a static state in the force balance and moment balance states.

When the motion assembly 300 of the inside world works along the X-direction and the Y-direction, the inside world generates bending moments in the Rx-direction and the Ry-direction because the motor output height of the motion assembly 300 and the output heights of the voice coil motors of the vibration damping platform are not at the same height. The control module 7 synchronously generates corresponding moments by driving the 4Z-direction voice coil motors 53 of the vibration reduction platform according to specific motion path decoupling calculation, and acts on the internal world to balance the moments in the Rx direction and the Ry direction, and the internal world always keeps a static state in a moment balance state.

When the motion assembly 300 of the inside world is operated in the X-direction or the Y-direction, the motion assembly 300 and the load 400 move in the X-direction or the Y-direction, the center of gravity of the inside world will change in the X-direction or the Y-direction, the inside world has a motion tendency in the Z-direction, and a bending moment in the Rx-direction or the Ry-direction. The motion controller transmits the position change curve of the load platform 200 to the control module 7 while driving the load 400 to act through the motion assembly 300, and the control module 7 drives the 4Z-direction voice coil motors 53 of the vibration damping platform to synchronously generate a balance moment with the same amplitude and opposite direction as the change moment to act on the internal world, wherein the internal world always keeps a static state under the force balance and moment balance states.

The workpiece table with the vibration reduction platform has the vibration reduction function and the motion feedforward self-balancing function, and can be selected according to the motion of the load 400 in practical application, and the implementation is not particularly limited.

Example III

An embodiment III of the present invention provides a vibration damping platform control method for controlling the workpiece platform with the vibration damping platform according to the above embodiment II, as shown in FIG. 6, the vibration damping platform control method includes the following steps:

the sensor assembly 4 detects and obtains a speed value and/or a displacement value of the lower plate 1 and/or the upper plate 2, and converts the speed value and the displacement value into a first force value; specifically, the steps include: the absolute velocity sensor 41 detects velocity values of 6 degrees of freedom of the upper plate 2, the ground velocity sensor 42 detects velocity values of 3 degrees of freedom of the lower plate 1, and the displacement sensor 43 detects displacement values of 3 degrees of freedom of the upper plate 2 with respect to the lower plate 1.

The motion controller detects a motion reaction force and/or a motion reaction force moment applied to the upper top plate 2 by the motion assembly 300 and converts the motion reaction force and/or the motion reaction force moment into a second force value; specifically, the steps include: according to the acceleration curve and the position curve output by the motion controller, an X-direction motion counter force and/or a Y-direction motion counter force and/or a Z-direction motion counter force and/or an Rx-direction motion counter force moment and/or an Ry-direction motion counter force moment and/or an Rz-direction motion counter force moment applied to the upper top plate 2 by the motion assembly 300 are calculated.

Finally, the first force value and the second force value are weighted and distributed to the plurality of voice coil motors, and the mover ends 50 of the plurality of voice coil motors are controlled to drive the upper top plate 2 respectively so as to keep the upper top plate 2 stationary.

The vibration damping platform control method according to the third embodiment of the present invention is used for controlling the workpiece platform with the vibration damping platform according to the second embodiment, and converts the detection value of the sensor assembly 4 and the acceleration curve and the position curve output by the motion controller into the first force value and the second force value to control the mover ends 50 of the plurality of voice coil motors to respectively drive the upper top plate 2, so as to keep the upper top plate 2 stationary, thereby realizing vibration damping control and motion self-balancing control on the workpiece platform, and ensuring that the inside world always remains stationary so as to improve the motion accuracy control of the workpiece platform on the load.

The specific control strategy of the vibration reduction platform control method can be divided into a vibration reduction function and a motion self-balancing function. The vibration damping function may be used to distribute a first force and the motion self-balancing function may be used to distribute a second force. Specifically, the vibration reduction platform control method consists of a speed loop, a position loop, a foundation feedforward loop and 4 control loops of a motion feedforward loop, so as to realize closed-loop control of the vibration reduction platform, and the specific implementation process is as follows:

1. Speed ring: the absolute speed sensor 41 mounted to the upper top plate 2 of the vibration damping platform transmits the measured 6-directional speed signals to the control module 7. After decoupling, the control module 7 obtains velocity values of 6 degrees of freedom of the upper top plate 2 in the X direction, the Y direction, the Z direction, the Rx direction, the Ry direction and the Rz direction, multiplies a certain damping coefficient (Csky) to convert the velocity values into force values, takes the force values as a part of the first force values, and then distributes the force values to 4Z-direction voice coil motors 53, 2X-direction voice coil motors 51 and 2Y-direction voice coil motors 52 in a weighting manner, so that the ceiling damping is realized, and the vibration of the upper top plate 2 is inhibited.

2. Position ring: the displacement sensor 43 mounted on the lower plate 1 of the vibration damping platform transmits the measured position signals in 3 directions to the control module 7. After decoupling, the control module 7 obtains the position values of 3 degrees of freedom of the upper top plate 2 relative to the lower bottom plate 1 in the X direction, the Y direction and the Rz direction, multiplies the position values by a certain proportionality coefficient (P) to convert the position values into force values, and then as a part of the first force values, weights the force values to be distributed to 2X-direction voice coil motors 51 and 2Y-direction voice coil motors 52, so that the upper top plate 2 of the vibration reduction platform is kept at a certain position.

3. Foundation feed-forward ring: the ground speed sensor 42 mounted to the lower plate 1 (or ground) of the vibration damping platform transmits the measured speed signals of 3 directions to the control module 7. The control module 7 multiplies the velocity values of 3 degrees of freedom in the X direction, Y direction and Z direction of the lower plate 1 (or foundation) by a certain damping coefficient to convert the velocity values into force values, and as a part of the first force values, weights the force values to 4Z-direction voice coil motors 53, 2X-direction voice coil motors 51 and 2Y-direction voice coil motors 52 to suppress the vibration of the upper plate 2 of the vibration damping platform.

4. A motion feed-forward loop: the control module 7 calculates an X-direction motion reaction force, a Y-direction motion reaction force, a Z-direction motion reaction force, an Rx-direction motion reaction force moment, an Ry-direction motion reaction force moment and an Rz-direction motion reaction force moment which are applied to the upper top plate 2 by the upper portion of the vibration damping platform according to an acceleration curve and a position curve which are output by the motion controller, converts the X-direction motion reaction force, the Y-direction motion reaction force, the Z-direction motion reaction force moment and the Rz-direction motion reaction force moment into second force values, and distributes the second force values to the 4Z-direction voice coil motors 53, the 2X-direction voice coil motors 51 and the 2Y-direction voice coil motors 52 in a weighting mode, so that force balance and moment balance of the upper portion (the inside world) of the vibration damping platform are realized, and the upper portion of the vibration damping platform is kept stationary.

The control module 7 adds the first force value and the second force value calculated by the 4 loops, and respectively drives a plurality of voice coil motors to realize the force values, so that the upper top plate 2 of the vibration reduction platform and the load platform 200 are kept relatively static, and vibration reduction and motion self-balancing of the vibration reduction platform are realized.

It is to be understood that the above examples of the present invention are provided for clarity of illustration only and are not limiting of the embodiments of the present invention. Various obvious changes, rearrangements and substitutions can be made by those skilled in the art without departing from the scope of the invention. It is not necessary here nor is it exhaustive of all embodiments. Any modification, equivalent replacement, improvement, etc. which come within the spirit and principles of the invention are desired to be protected by the following claims.

Claims

1. Damping platform, its characterized in that includes:

-a lower base plate (1), said lower base plate (1) being connectable to a support structure;

an upper top plate (2), the upper top plate (2) being for supporting a load (400);

the air bearing (3) is arranged between the lower bottom plate (1) and the upper top plate (2), and the air bearing (3) is used for floatingly supporting the upper top plate (2);

a sensor assembly (4), wherein the sensor assembly (4) is arranged between the lower bottom plate (1) and the upper top plate (2), and the sensor assembly (4) is used for detecting a speed value or a displacement value of the lower bottom plate (1) and/or the upper top plate (2);

the voice coil motors are arranged between the lower bottom plate (1) and the upper top plate (2), the voice coil motors are in communication connection with the sensor assembly (4), and the rotor ends (50) of the voice coil motors can apply acting force or acting moment to the upper top plate (2) so as to enable the upper top plate (2) to keep static.

2. Damping platform according to claim 1, characterized in that the sensor assembly (4) comprises:

at least one absolute speed sensor (41), wherein the absolute speed sensor (41) is fixedly connected to the upper top plate (2), and the absolute speed sensor (41) is used for detecting the absolute speed value of the upper top plate (2);

At least one foundation speed sensor (42), wherein the foundation speed sensor (42) is fixedly connected to the lower base plate (1), and the foundation speed sensor (42) is used for detecting the speed value of the lower base plate (1);

and the displacement sensor (43) is fixedly connected to the lower bottom plate (1), and the displacement sensor (43) is used for detecting the displacement value of the upper top plate (2) relative to the lower bottom plate (1).

3. Vibration damping platform according to claim 2, characterized in that the voice coil motor comprises at least one X-direction voice coil motor (51), at least one Y-direction voice coil motor (52) and at least one Z-direction voice coil motor (53), the X-direction voice coil motor (51) being used for driving the X-direction movement of the upper top plate (2), the Y-direction voice coil motor (52) being used for driving the Y-direction movement of the upper top plate (2), the Z-direction voice coil motor (53) being used for driving the Z-direction movement of the upper top plate (2).

4. Damping platform according to claim 1, characterized in that the air bearing (3) comprises:

the base (31), the said base (31) is fixedly connected to the said lower floor (1);

an upper floating plate (32), wherein the upper floating plate (32) is fixedly connected to the upper top plate (2);

the air supporting piece (33), air supporting piece (33) connect in on base (31), be provided with a plurality of orifices (331) on air supporting piece (33), the one end intercommunication outside air supply of orifice (331), the other end orientation go up floating plate (32), air supporting piece (33) with it has floating clearance (34) to go up between floating plate (32), outside air supply is used for providing positive pressure gas so that air supporting piece (33) floating support go up floating plate (32).

5. The vibration reduction platform according to claim 1, further comprising a limit assembly (6), the limit assembly (6) comprising a plurality of limit pieces (61), the limit pieces (61) comprising a limit rod (611) and a limit seat (612), the limit seat (612) being fixedly connected to the lower plate (1), the limit rod (611) being fixedly connected to the upper plate (2), the limit rod (611) being slidably arranged in the limit seat (612), the limit pieces (61) being adapted to limit the distance between the upper plate (2) and the lower plate (1).

6. A workpiece stage with a vibration reduction platform, comprising a vibration reduction platform according to any one of claims 1-5, the workpiece stage with vibration reduction platform further comprising:

-a support frame (100), the support frame (100) being adapted to support the lower plate (1), the lower plate (1) being detachably connected to the support frame (100);

the load platform (200) is detachably connected to the upper top plate (2) and is arranged on one side, away from the lower bottom plate (1), of the upper top plate (2);

the motion assembly (300), motion assembly (300) set up in on load platform (200), motion assembly (300) are used for driving load (400) motion, motion assembly (300) include motion controller, motion controller is used for controlling motion speed of motion assembly (300), motion controller communication connection voice coil motor.

7. The workpiece stage with vibration reduction stage according to claim 6, wherein the motion assembly (300) comprises an X-axis motion structure (301) and a Y-axis motion structure (302), the X-axis motion structure (301) being fixedly connected to the load stage (200), the Y-axis motion structure (302) being slidably connected to the X-axis motion structure (301), the load (400) being slidably connected to the Y-axis motion structure (302).

8. A vibration damping platform control method for controlling a work table with a vibration damping platform according to claim 6, comprising the steps of:

the sensor assembly (4) detects and obtains a speed value and/or a displacement value of the lower bottom plate (1) and/or the upper top plate (2), and converts the speed value and the displacement value into a first force value;

a motion controller detects a motion reaction force and/or a motion reaction force moment applied to the upper top plate (2) by a motion assembly (300) and converts the motion reaction force and/or the motion reaction force moment into a second force value;

the first force value and the second force value are weighted and distributed to a plurality of voice coil motors, and rotor ends (50) of the voice coil motors are controlled to drive the upper top plate (2) respectively so as to keep the upper top plate (2) stationary.

9. The vibration damping platform control method according to claim 8, characterized in that the sensor assembly (4) detects and obtains a velocity value and/or a displacement value of the lower bottom plate (1) and/or the upper top plate (2), in particular comprising: an absolute velocity sensor (41) detects velocity values of 6 degrees of freedom of the upper plate (2), a ground velocity sensor (42) detects velocity values of 3 degrees of freedom of the lower plate (1), and a displacement sensor (43) detects position values of 3 degrees of freedom of the upper plate (2) with respect to the lower plate (1).

10. The vibration damping platform control method according to claim 8, characterized in that the motion controller detects a motion reaction force and/or a motion reaction force moment applied to the upper top plate (2) by the motion assembly (300), specifically comprising: and according to the acceleration curve and the position curve output by the motion controller, calculating an X-direction motion counter force and/or a Y-direction motion counter force and/or a Z-direction motion counter force and/or an Rx-direction motion counter force moment and/or an Ry-direction motion counter force moment and/or an Rz-direction motion counter force moment applied to the upper top plate (2) by the motion assembly (300).