Two-dimensional air-floating workpiece table with vibration reduction function

Abstract

The invention relates to a two-dimensional air-floating workpiece table with a vibration reduction function, and belongs to the technical field of ultra-precision motion control. Comprising a base, a cross beam assembly and a micro-motion assembly, and in the cross beam assembly, flexible hinges are installed on the two sides of a cross beam; the Y-axis air floating bottom plate is preloaded on the base; the Y-axis air floating plate is mounted on the flexible hinge and is loaded on the Y-axis air floating bottom plate; the X-axis linear dampers are distributed at the joint of the flexible hinge and the cross beam; in the micro-motion assembly, a Y-axis air floating guide rail is mounted on a base; the voice coil motor mounting block is fixedly mounted on the Y-axis air floating guide rail; and the voice coil motor is mounted on the voice coil motor mounting block. The technical problems that in the prior art, due to the fact that the load mass of a voice coil motor is large, when the voice coil motor is subjected to vibration reduction, the needed vibration reduction stroke is increased, and the voice coil motor has deviation in vibration reduction of a platform in a motion state are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of ultra-precision motion control, and in particular relates to a two-dimensional air-floating workpiece table with a vibration reduction function. Background Art

[0002] At present, air-floating motion platforms are widely used in wafer inspection because of their high motion accuracy, cleanliness and pollution-free characteristics. Existing air-floating motion platforms often use air-floating guide rails to achieve smooth movement without friction and vibration.

[0003] The air-floating motion platform needs to be used with a high-precision marble workbench. During the motion of the motion platform, due to the relationship between the action force and the reaction force, the movement of the air-floating platform will cause the marble workbench to vibrate (especially in situations with large motion inertia, large acceleration and deceleration, and high dynamic response). Due to the vibration of the marble workbench, the dynamic and static performance of the system is reduced. In a set of equipment, the motion platform usually needs to work with other systems (such as optical detection systems, optical processing systems, etc.).

[0004] Usually, in ultra-precision motion control applications, in order to reduce the vibration of the system, it is necessary to configure a relatively expensive active vibration isolation table to achieve the vibration reduction effect.

[0005] The patent with announcement number: CN116146654A discloses a vibration reduction platform, a workpiece table with a vibration reduction platform and a vibration reduction platform control method, including a lower bottom plate, an upper top plate, multiple air bearings, a sensor assembly and multiple voice coil motors; the upper top plate supports the load; the air bearing is arranged between the lower bottom plate and the upper top plate, floatingly supporting the upper top plate; the sensor assembly is arranged between the lower bottom plate and the upper top plate, and the sensor assembly detects the speed value or 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 communicatively connected to the sensor assembly, and the mover end of the voice coil motor can apply a force or a torque to the upper top plate to keep the upper top plate stationary.

[0006] The prior art has at least the following problems during use:

[0007] The active vibration isolation platform in the prior art is difficult to control, and each moving structure in the moving assembly needs to ensure structural rigidity, and deformation caused by thermal expansion and contraction will affect the control accuracy. Summary of the invention

[0008] The present invention provides a two-dimensional air-floating workpiece table with a vibration reduction function, which is used to solve the technical problems in the prior art that due to the large load mass of the voice coil motor, the vibration reduction stroke required for the voice coil motor becomes larger during vibration reduction, and there is a deviation in the vibration reduction of the platform in a moving state by the voice coil motor.

[0009] In order to achieve the above object, the present invention is implemented by the following technical solutions:

[0010] A two-dimensional air-floating workpiece table with a vibration reduction function includes: a base, a crossbeam assembly, and a micro-motion assembly. The crossbeam assembly is installed on the base, and the micro-motion assembly is located on both sides of the crossbeam assembly. The crossbeam assembly includes: a crossbeam, a flexible hinge, a Y-axis air-floating bottom plate, a Y-axis air-floating plate, and an X-axis linear damper. The flexible hinges are installed on both sides of the crossbeam; the Y-axis air-floating bottom plate is suspended on the base in a vacuum preloaded manner; the Y-axis air-floating plate is installed on the flexible hinges on both sides and is suspended on the Y-axis air-floating bottom plate in a vacuum preloaded manner; the X-axis linear damper is distributed at the connection between the flexible hinge and the crossbeam; the micro-motion assembly includes: a Y-axis air-floating guide rail, a voice coil motor mounting block, and a voice coil motor. The Y-axis air-floating guide rail is installed on the base, located on both sides of the Y-axis air-floating bottom plate, and is used to limit the sliding direction of the Y-axis air-floating plate; the voice coil motor mounting block is fixedly installed on the Y-axis air-floating guide rail; and the voice coil motor is installed on the voice coil motor mounting block.

[0011] Furthermore, the crossbeam assembly also includes: an X-axis air-floating bottom plate, an X-axis air-floating side plate, an X-axis linear motor, and an X-axis top plate. The X-axis air-floating bottom plate is suspended on the base through vacuum preloading; the X-axis air-floating side plates are suspended on both sides of the crossbeam through the air film gap, sliding with the crossbeam as a guide rail to assist movement in the X-axis direction; the X-axis linear motor has a stator and a mover, the stator is fixed on the crossbeam, and the mover is fixed on the X-axis top plate; the X-axis top plate is installed on the X-axis linear motor.

[0012] Furthermore, the crossbeam assembly further includes: an X-axis reading head bracket, an X-axis reading head, an X-axis grating ruler bracket, and an X-axis grating ruler. The X-axis reading head bracket is mounted on the crossbeam; the X-axis reading head is mounted on the X-axis reading head bracket; the X-axis grating ruler bracket is mounted on the crossbeam; the X-axis grating ruler is mounted on the X-axis grating ruler bracket and cooperates with the X-axis reading head to realize position feedback.

[0013] Furthermore, the flexible hinge has a main side flexible hinge and an auxiliary flexible hinge, the auxiliary flexible hinge is hingedly mounted with the main side flexible hinge, the main side flexible hinge is mounted on both sides of the crossbeam, the crossbeam is appropriately flexible in the X direction and in the direction of rotation around the Z axis, and together with the X-axis linear damper constitutes passive vibration reduction in the X direction.

[0014] Furthermore, the micro-motion assembly also includes: a cross roller guide, a micro-motion slide, a Y-axis linear motor, a Y-axis linear damper, and a Y-axis feedback assembly. The cross roller guide is mounted on the base; the micro-motion slide is slidably mounted on the cross roller guide; the Y-axis linear motor is mounted on the micro-motion slide; one end of the Y-axis linear damper is fixed on the Y-axis air-floating guide, and the other end is fixed on the micro-motion slide, and is used to provide passive vibration reduction for the movement of the beam in the Y direction; the Y-axis feedback assembly is used to feedback the Y-axis position information.

[0015] Furthermore, the micro-motion assembly further includes: a micro-motion unit reading head, a micro-motion unit grating ruler, and a motor connecting plate. The micro-motion unit reading head is mounted on the base plate; the micro-motion unit grating ruler is mounted on the micro-motion slide plate and cooperates with the micro-motion unit reading head to realize position feedback; and the motor connecting plate connects the Y-axis linear motor and the crossbeam.

[0016] Furthermore, the Y-axis feedback component has a Y-axis reading head and a Y-axis grating ruler. The Y-axis reading head is installed on the motor connecting plate and forms a feedback system with the Y-axis grating ruler to provide real-time feedback on the actual position of the system in the Y direction; the Y-axis grating ruler is installed on the Y-axis air-floating guide rail and cooperates with the Y-axis reading head to realize Y-direction position feedback.

[0017] The present invention provides a two-dimensional air-floating workpiece table with a vibration reduction function, which has the following beneficial effects:

[0018] The flexible hinge is designed to be appropriately flexible in the X direction and the rotation direction around the Z axis, and rigid in the Y direction. While ensuring the rigidity of the beam in the direction of movement, its flexible design can absorb the deformation of the beam caused by thermal expansion and contraction. X-axis linear dampers are designed on both sides of the flexible hinge of the beam to control the vibration in the X direction and improve the control bandwidth of the high X axis. In terms of double Y vibration suppression, a micro-motion system is designed while adding an X-axis linear damper, and a voice coil motor is used to drive the micro-motion system to achieve the effect of active vibration suppression. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 A front view of a two-dimensional air-floating workpiece table with a vibration reduction function provided by an embodiment of the present invention;

[0021] Figure 2A top view of a two-dimensional air-floating workpiece table with a vibration reduction function provided by an embodiment of the present invention;

[0022] Figure 3 A cross-sectional view of the installation structure of the beam assembly provided by an embodiment of the present invention;

[0023] Figure 4 A side view of a two-dimensional air-floating workpiece table with a vibration reduction function provided by an embodiment of the present invention;

[0024] Figure 5 A cross-sectional view of the installation structure of the micro-motion assembly provided by an embodiment of the present invention;

[0025] Figure 6 A schematic diagram of the structure of a Y-axis feedback component provided in an embodiment of the present invention;

[0026] Figure 7 A flow chart of the control system provided by an embodiment of the present invention.

[0027] In the figure: 1-base; 2-beam assembly; 201-beam; 202-X-axis air-floating bottom plate; 203-X-axis air-floating side plate; 204-X-axis top plate; 205-X-axis linear motor; 206-X-axis reading head bracket; 207-X-axis reading head; 208-X-axis grating ruler; 209-X-axis grating ruler bracket; 210-Y-axis side air-floating plate; 211-main side flexible hinge; 212-Y-axis air-floating bottom plate; 213-X-axis linear damper; 214-auxiliary flexible Hinge; 3-micro-motion assembly; 31-Y-axis air-floating guide; 32-micro-motion slide plate; 33-Y-axis linear motor; 331-Y-axis linear motor mover; 332-Y-axis linear motor stator; 34-Y-axis linear damper; 35-voice coil motor; 36-voice coil motor mounting block; 37-cross roller guide; 38-micro-motion unit reading head; 39-micro-motion unit grating ruler; 4-motor connecting plate; 5-Y-axis feedback assembly; 51-Y-axis reading head; 52-Y-axis grating ruler. DETAILED DESCRIPTION

[0028] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0029] In the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0030] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0031] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be welding, bolt connection, or riveting; it can be fixed connection, detachable connection, or integral connection; it can be mechanical connection or electrical connection; it can be directly connected or indirectly connected through an intermediate medium, or it can be internal communication between two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0032] Example:

[0033] like Figures 1 to 6 As shown, the design is mainly composed of a base 1, a beam assembly 2, a micro-motion assembly 3, motor connecting plates 4 on both sides, and Y-axis feedback assemblies 5 on both sides. The crossbeam assembly 2 is composed of a crossbeam 201, an X-axis air-floating bottom plate 202, X-axis air-floating side plates 203 on both sides, an X-axis top plate 204, an X-axis linear motor 205, an X-axis reading head bracket 206, an X-axis reading head 207, an X-axis grating scale 208, an X-axis grating scale bracket 209, Y-axis side air-floating plates 210 on both sides of the crossbeam 201, a main side flexible hinge 211, a Y-axis air-floating bottom plate 212, 4 X-axis linear dampers 213 installed on the diagonal sides of the crossbeam, and an auxiliary flexible hinge 214; the micro-motion assembly 3 is composed of a Y-axis air-floating guide rail 31, a micro-motion slide plate 32, a Y-axis linear motor 33, a Y-axis linear damper 34, voice coil motors 35 on both sides, a voice coil motor mounting block 36, a cross roller guide rail 37, a micro-motion unit reading head 38, and a micro-motion unit grating scale 39. The Y-axis linear motor 33 is composed of a Y-axis linear motor mover 331 and a Y-axis linear motor stator 332. The Y-axis feedback component 5 is composed of a Y-axis reading head 51 and a Y-axis grating ruler 52.

[0034] like Figure 1 , Figure 2 and Figure 3As shown, the X-axis air-floating bottom plate 202, the X-axis air-floating side plates 203 on both sides and the X-axis top plate 204 in the beam assembly 2 are surrounded on the beam 201 in a U-shape, wherein the X-axis air-floating bottom plate 202 is suspended on the base 1 in the form of vacuum preloading, and the X-axis air-floating side plates 203 are suspended on both sides of the beam 201 through the air film gap, and slide with the beam 201 as a guide rail, and an X-axis linear motor 205 is installed on the upper surface of the beam 201, the stator of the X-axis linear motor is fixedly installed on the beam 201, and the mover of the X-axis linear motor is fixedly installed on the X-axis top plate 204, which is used to provide power for the movement of the device in the X-axis direction. The X-axis grating ruler 208 is installed on the crossbeam 201 through the X-axis grating ruler bracket 209, and the X-axis reading head 207 is installed on the X-axis top plate through the X-axis reading head bracket 206. When the X-axis top plate moves, the feedback system composed of the X-axis reading 207 and the X-axis grating ruler 208 feeds back the position information of the X-axis top plate in the X direction in real time. The main side flexible hinge 211 and the auxiliary flexible hinge 214 are fixedly installed on both sides of the crossbeam 201. The Y-axis side air-floating plate 210 is installed on the other side of the flexible hinge. The Y-axis side air-floating plate 210 is suspended on the inner side of the Y-axis air-floating guide rail 31 in the micro-motion component 3 in a vacuum preloaded manner, and moves in the Y direction guided by the Y-axis air-floating guide rail 31. Two Y-axis air-floating bottom plates 212 are fixedly installed on the bottom surface of both sides of the crossbeam 201, and the Y-axis air-floating bottom plates 212 are suspended on the base 1 in a vacuum preloaded manner. The X-axis linear dampers 213 are arranged in pairs, with one end fixed on the crossbeam 201 and the other end fixed on the main side flexible hinge 211 and the auxiliary flexible hinge 214 respectively, to reduce the vibration in the X direction caused by the operation of the X-axis linear motor 205.

[0035] like Figure 5 As shown, the fine motion slide plate 32 in the fine motion assembly 3 is installed on the Y-axis air-floating guide rail 31 through a cross roller guide rail 37, and can generate relative motion with the Y-axis air-floating guide rail 31 along the Y direction. The fine motion unit reading head 38 installed on the Y-axis air-floating guide rail 31 and the fine motion unit grating ruler 39 installed on the fine motion slide plate 32 form the feedback system of the fine motion assembly 3, and the actual position of the fine motion slide plate 32 is fed back in real time. The stator 332 of the Y-axis linear motor is fixedly connected to the fine motion slide plate 32, and the mover of the Y-axis linear motor is connected to the crossbeam assembly 2 through the motor connecting plate 4, providing power for the Y-direction movement of the system. Voice coil motors 35 are respectively installed on both sides of the fine motion slide plate 32, and the stator of the voice coil motor 35 is fixed on the Y-axis air-floating guide rail 31 through the voice coil motor mounting block 36, and the mover of the voice coil motor 35 is fixedly connected to the fine motion slide plate 32, providing power for active vibration reduction in the Y direction of the system. Y-axis linear dampers 34 are installed on both sides of the micro-motion slide 32. One end of the Y-axis linear damper is fixed on the Y-axis air-floating guide rail 31, and the other end is fixed on the micro-motion slide 32, providing passive vibration reduction for the system in the Y direction.

[0036] The Y-axis reading head 51 mounted on the motor connecting plate 4 and the Y-axis grating ruler 51 mounted on the Y-axis air-floating guide rail 31 form a Y-axis feedback assembly 5, which provides real-time feedback of the actual position of the system in the Y direction. The micro-motion assembly 3, the motor connecting plate 4 and the Y-axis feedback assembly 5 are symmetrically mounted on both sides of the base 1, and after being connected with the crossbeam assembly, they form an H-shaped two-dimensional air-floating motion platform.

[0037] Control system such as Figure 7 As shown, when working, a PC generates a motion trajectory and outputs it to the motion system controller. The controller outputs a motion command to the constant motion system driver (the motion command contains command information such as displacement, speed, acceleration, etc. of the motion axis). The driver then drives the X-axis linear motor 205 and the Y-axis linear motor 33, thereby driving the X-axis top plate 204 to move. The X-axis reading head 207 fixed on the X-axis top plate 204 feeds back the actual position information of the X-axis top plate 204, and the Y-axis reading head 51 fixed on the motor connecting plate 4 feeds back the actual position information of the system in the Y direction, and outputs the feedback signal to the controller, thereby realizing full closed-loop control of the motion system.

[0038] When the linear motor is in action, due to the mutuality of force, the stator of the linear motor will be subjected to a reverse force, which will cause the stator of the linear motor to move in the opposite direction. In ultra-precision motion control, the manifestation of this motion is vibration.

[0039] In this solution, the reaction force of the X-axis linear motor 205 drives the crossbeam 201 to move, and the main side flexible hinges 211 and the auxiliary flexible hinges 214 installed on both sides of the crossbeam will produce elastic deformation. At the same time, the movement of the X-axis linear dampers 213 installed on both sides of the crossbeam will produce linear damping. The elasticity of the flexible hinges and the linear damping of the linear dampers together constitute the passive vibration reduction of the system in the X direction. At the same time, the elastic deformation of the main side flexible hinges 211 and the auxiliary flexible hinges 214 will absorb the thermal deformation of the crossbeam caused by temperature changes, so the crossbeam material can be selected from materials with lower manufacturing costs (such as aviation aluminum).

[0040] In this solution, the Y-axis linear motor stator 332 is installed on the movable micro-motion slide 32. The reaction force generated by the Y-axis linear motor 33 will drive the micro-motion slide 32 to move along the cross roller guide 37. When it moves, it will drive the Y-axis linear damper 34 installed on both sides of the micro-motion slide 32 to move, thereby generating linear damping and achieving the effect of passive vibration reduction.

[0041] At the same time, the micro-motion unit reading head 38 feeds back the displacement of the micro-motion slide 32 by reading the displacement of the micro-motion unit grating scale 39, and outputs the feedback information to the controller. The controller forms a vibration prediction through the acceleration feedforward of the constant motion axis and the feedback information (displacement, velocity, acceleration) of the micro-motion axis, and outputs a vibration suppression instruction to the micro-motion system driver. The micro-motion system driver drives the voice coil motor 35 to achieve the effect of active vibration reduction.

[0042] In summary, when using a two-dimensional air-floating workpiece table with a vibration reduction function, redundant devices outside the motion platform can be reduced, the control bandwidth of the motion platform can be improved, and the performance of the vibration reduction system can be improved by using a combination of active and passive vibration reduction.

[0043] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A two-dimensional air-floating workpiece table with a vibration reduction function, comprising: A base (1), a crossbeam assembly (2), and a micro-motion assembly (3), wherein the crossbeam assembly (2) is mounted on the base (1), and the micro-motion assembly (3) is located on both sides of the crossbeam assembly (2); The crossbeam assembly (2) comprises: beam (201); Flexible hinges, mounted on both sides of the crossbeam (201); A Y-axis air-floating bottom plate (212) is suspended on the base (1) in a vacuum pre-loaded manner; A Y-axis air-floating plate, mounted on the flexible hinges on both sides, suspended on the Y-axis air-floating bottom plate (212) in a vacuum pre-loaded manner; An X-axis linear damper (213) is distributed at the connection between the flexible hinge and the crossbeam (201); The micro-motion component (3) comprises: Y-axis air-floating guide rails (31), mounted on the base (1), located on both sides of the Y-axis air-floating bottom plate (212), and used to limit the sliding direction of the Y-axis air-floating plate; A voice coil motor mounting block (36) fixedly mounted on the Y-axis air-floating guide rail (31); A voice coil motor (35) is mounted on the voice coil motor mounting block (36).

2. The two-dimensional air-floating workpiece table with vibration reduction function according to claim 1, characterized in that: The crossbeam assembly (2) further comprises: An X-axis air-floating bottom plate (202) is suspended on the base (1) by vacuum preloading; The X-axis air-floating side plates (203) are suspended on both sides of the crossbeam (201) through the air film gap, and slide using the crossbeam (201) as a guide rail to assist movement in the X-axis direction; An X-axis linear motor (205), the X-axis linear motor (205) comprising a stator and a mover, the stator being fixed on the crossbeam (201), and the mover being fixed on the X-axis top plate (204); The X-axis top plate (204) is mounted on the X-axis linear motor (205).

3. The two-dimensional air-floating workpiece table with vibration reduction function according to claim 2, characterized in that: The crossbeam assembly (2) further comprises: An X-axis reading head bracket (206) mounted on the crossbeam (201); An X-axis reading head (207) mounted on the X-axis reading head bracket (206); An X-axis grating scale bracket (209) mounted on the crossbeam (201); The X-axis grating ruler (208) is mounted on the X-axis grating ruler bracket (209) and cooperates with the X-axis reading head (207) to realize position feedback.

4. The two-dimensional air-floating workpiece table with vibration reduction function according to claim 3, characterized in that: The flexible hinge comprises a main side flexible hinge (211) and an auxiliary flexible hinge (214); the auxiliary flexible hinge (214) is hingedly mounted on the main side flexible hinge (211); the main side flexible hinge (211) is mounted on both sides of the crossbeam (201); the crossbeam (201) is appropriately flexible in the X direction and in the direction of rotation around the Z axis, and together with the X-axis linear damper (213) forms passive vibration reduction in the X direction.

5. The two-dimensional air-floating workpiece table with vibration reduction function according to claim 3, characterized in that: The micro-motion component (3) further comprises: A cross roller guide rail (37) mounted on the base (1); A micro-motion slide plate (32) slidably mounted on the cross roller guide rail (37); A Y-axis linear motor (33) mounted on the micro-motion slide plate (32); A Y-axis linear damper (34), one end of which is fixed on the Y-axis air-floating guide rail (31) and the other end of which is fixed on the micro-motion slide plate (32), and is used to provide a passive vibration reduction effect for the movement of the crossbeam (201) in the Y direction; The Y-axis feedback component (5) is used to feedback the Y-axis position information.

6. The two-dimensional air-floating workpiece table with vibration reduction function according to claim 3, characterized in that: The micro-motion component (3) further comprises: A micro-motion unit reading head (38) mounted on the base plate; A micro-motion unit grating ruler (39) is mounted on the micro-motion slide plate (32) and cooperates with the micro-motion unit reading head (38) to achieve position feedback; A motor connecting plate (4) connects the Y-axis linear motor (33) and the crossbeam (201).

7. The two-dimensional air-floating workpiece table with vibration reduction function according to claim 3, characterized in that: The Y-axis feedback component (5) comprises a Y-axis reading head (51) and a Y-axis grating ruler (52); the Y-axis reading head (51) is mounted on the motor connecting plate (4) and forms a feedback system with the Y-axis grating ruler (52) to provide real-time feedback of the actual position of the system in the Y direction; the Y-axis grating ruler (52) is mounted on the Y-axis air-floating guide rail (31) and cooperates with the Y-axis reading head (51) to achieve Y-direction position feedback.

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