Single-degree-of-freedom composite driving adjustable stiffness micro-motion platform

Abstract

This invention discloses a single-degree-of-freedom composite-driven adjustable stiffness micro-motion platform, relating to the field of precision motion platform technology. It can achieve real-time stiffness adjustment while ensuring precise micro-motion. The specific solution is as follows: A single-degree-of-freedom composite-driven adjustable stiffness micro-motion platform includes a flexible micro-motion platform with a stage at its center. A composite parallel guide flexible component is provided on the first opposite side of the stage. A piezoelectric ceramic actuator is installed on one side of the second opposite side of the stage. A normal stress electromagnetic adjustable stiffness actuator is installed on the second opposite side of the stage and is positioned opposite to the piezoelectric ceramic actuator. It includes a T-shaped stator core, with an excitation coil on the winding square column in the middle of the T-shaped stator core. L-shaped stator cores are provided on both sides of the excitation coil. The first end of the L-shaped stator core is connected to the T-shaped stator core, and an air gap is provided between the second end and the armature. The normal stress electromagnetic adjustable stiffness actuator is connected to the flexible micro-motion platform through the armature. External leads are connected to the excitation coil to adjust the stiffness.

Description

Technical Field

[0001] This invention relates to the field of precision motion platform technology, and in particular to a single-degree-of-freedom composite-driven adjustable stiffness micro-motion platform. Background Technology

[0002] Micro-motion platforms are key components in micro- and nano-scale manufacturing processes, with significant applications in chip manufacturing, ultra-precision machining, and high-energy beam control. Current technologies for composite-driven micro-motion platforms primarily focus on increasing degrees of freedom through serial drives or extending stroke through macro- and micro-drives, failing to achieve real-time online stiffness adjustment while maintaining precise motion through composite drives. The inability to adjust the frequency significantly limits the application range of micro-motion platforms.

[0003] For special applications such as high aspect ratio nanoimprinting and ion etching, a micro-motion platform needs to switch back and forth between large-stroke motion and high-precision micro-motion. Traditional micro-motion platforms with non-adjustable stiffness cannot meet this requirement at the same time, and replacing them with different types of micro-motion platforms will greatly increase equipment costs and debugging time. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide a single-degree-of-freedom composite-driven adjustable stiffness micro-motion platform, which can achieve real-time online adjustment of stiffness while ensuring precise micro-motion.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0006] A single-degree-of-freedom composite-driven adjustable stiffness micro-motion platform includes:

[0007] The flexible micro-motion platform has a stage at its center, a composite parallel guide flexible component on the first opposite side of the stage, and a piezoelectric ceramic actuator installed on one side of the second opposite side of the stage. The piezoelectric ceramic actuator is connected to the stage through a differential lever amplification flexible component.

[0008] The normal stress electromagnetic adjustable stiffness actuator is installed on the second opposite side of the stage and is positioned opposite to the piezoelectric ceramic actuator. It includes a T-shaped stator core, an excitation coil is provided on the winding post in the middle of the T-shaped stator core, and L-shaped stator cores are provided on both sides of the excitation coil. The first end of the L-shaped stator core is connected to the T-shaped stator core, and an air gap is provided between the second end and the armature. The normal stress electromagnetic adjustable stiffness actuator is connected to the flexible micro-motion platform through the armature, and the excitation coil is connected to an external lead to adjust the stiffness.

[0009] As a further implementation, the normal stress electromagnetic adjustable stiffness actuator also includes an upper shell and a lower shell arranged opposite to each other. A wire groove is provided at the middle position of the top of the upper shell and the lower shell, and an armature groove is provided at the bottom to connect the upper and lower ends of the armature. Flexible guide hinges connecting the armature groove are also provided on the upper shell and the lower shell.

[0010] As a further implementation, the upper and lower outer shells are also provided with stator core mounting slots to accommodate L-shaped and T-shaped stator cores, and the normal stress electromagnetic adjustable stiffness actuator has an axisymmetric structure.

[0011] As a further implementation, set screw holes are provided at the stator core mounting slots of the upper and lower outer shells, and set screws are used to tighten the L-shaped stator core.

[0012] As a further implementation, a piezoelectric ceramic actuator mounting groove is provided on one side of the second opposite side of the stage, and a differential lever amplification flexible component is provided on the first opposite side of the stage, employing a three-stage lever differential amplification.

[0013] As a further implementation, a piezoelectric ceramic actuator set screw mounting slot is provided on one side of the flexible micro-motion platform.

[0014] As a further implementation, a normal stress electromagnetic adjustable stiffness actuator mounting slot is provided at the middle position of the other side of the second opposite side of the stage. The flexible micro-motion platform is also provided with an armature mounting slot on one side of the normal stress electromagnetic adjustable stiffness actuator mounting slot for mounting an armature. The front and side of the armature mounting frame are slotted to form a magnetic flux loop.

[0015] As a further implementation, a guide beam is provided between the output end of the piezoelectric ceramic actuator and the input end of the differential lever amplification flexible component.

[0016] As a further implementation, an upper cover plate is also included, which is located on top of the flexible micro-motion platform. An opening is provided at the center of the upper cover plate to accommodate the platform. The bottom edge of the upper cover plate is provided with a wire-holding groove and a wire-running groove.

[0017] As a further implementation, a lower base plate is also included, which is located at the bottom of the flexible micro-motion platform. The lower base plate is U-shaped and its maximum width does not cover the flexible components.

[0018] The beneficial effects of the present invention are as follows:

[0019] 1. This invention establishes an adjustable stiffness micro-motion platform with a single-degree-of-freedom composite drive, comprising a normal stress electromagnetic adjustable stiffness actuator, a flexible micro-motion platform, and a piezoelectric ceramic actuator. The normal stress electromagnetic adjustable stiffness actuator is connected to the flexible micro-motion platform via an armature. An excitation coil is mounted on the winding square column in the middle of the T-shaped stator core. External leads are connected to the excitation coil to adjust the stiffness, enabling the micro-motion platform to achieve both high-precision micro-motion and real-time online stiffness adjustment.

[0020] 2. This invention uses a combination of piezoelectric ceramic actuator and flexible micro-motion platform to provide direct-drive, large-stroke, high-precision motion output. At the same time, by changing the stiffness through normal stress electromagnetic adjustable stiffness actuator, different force outputs can be achieved at the same position, which greatly expands the adaptability and motion range of the micro-motion platform.

[0021] 3. The micro-motion platform of the present invention adopts a symmetrical structural layout, with the normal stress electromagnetic adjustable stiffness actuator and the piezoelectric ceramic actuator distributed vertically, and the composite parallel guide mechanism distributed horizontally, resulting in a compact structure.

[0022] 4. The armature mounting frame of this invention can ensure the accurate relative position of the normal stress electromagnetic adjustable stiffness actuator and the flexible micro-motion platform. Attached Figure Description

[0023] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0024] Figure 1 This is a schematic diagram of a single-degree-of-freedom composite-driven adjustable stiffness micro-motion platform in an embodiment of the present invention.

[0025] Figure 2 This is an exploded view of a portion of the single-degree-of-freedom composite-driven adjustable stiffness micro-motion platform in an embodiment of the present invention.

[0026] Figure 3 This is a front view of the main structure of the adjustable stiffness micro-motion platform with single-degree-of-freedom composite drive in an embodiment of the present invention.

[0027] Figure 4 This is a partial view of the normal stress electromagnetic adjustable stiffness actuator in an embodiment of the present invention.

[0028] Figure 5 This is an exploded view of the components of the normal stress electromagnetic adjustable stiffness actuator in an embodiment of the present invention.

[0029] Figure 6 This is a schematic diagram of the upper and lower housings of the normal stress electromagnetic adjustable stiffness actuator in an embodiment of the present invention.

[0030] Figure 7This is a schematic diagram of the flexible micro-motion platform in an embodiment of the present invention.

[0031] Figure 8 This is a side view of the micro-motion platform in an embodiment of the present invention.

[0032] Figure 9 yes Figure 8 Cross-sectional view of the medium-flexible micro-motion platform (AA section).

[0033] Figure 10 This is a schematic diagram of the structure of the upper cover plate in an embodiment of the present invention.

[0034] The diagram exaggerates the spacing or dimensions between parts to show their positions; the diagram is for illustrative purposes only.

[0035] The components include: 1. Top cover plate; 2. Normal stress electromagnetic adjustable stiffness actuator; 3. Flexible micro-motion platform; 4. Bottom plate; 5. Piezoelectric ceramic actuator; 6. Upper housing; 7. Lower housing; 8. Armature; 9. L-shaped stator core; 10. T-shaped stator core; 11. Excitation coil; 12. Set screw; 13. Housing fixing screw; 14. Piezoelectric ceramic actuator set screw; 15. Wiring groove; 16. Platform fixing screw; 101. Wire clamping groove; 102. Wiring groove; 301. Differential lever amplification flexible component; 302. Composite parallel guide flexible component. Components: 303. Stage; 304. Armature mounting frame; 305. Mounting slot for normal stress electromagnetic adjustable stiffness actuator; 306. Mounting slot for piezoelectric ceramic actuator; 307. Mounting slot for piezoelectric ceramic actuator set screw; 601. Flexible guide hinge for upper housing; 602. Armature slot for upper housing; 603. Stator core mounting slot for upper housing; 604. Wire slot for upper housing; 701. Flexible guide hinge for lower housing; 702. Armature slot for lower housing; 703. Stator core mounting slot for lower housing; 704. Wire slot for lower housing; 705. Set screw hole. Detailed Implementation

[0036] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0037] Example 1

[0038] In a typical embodiment of the present invention, reference is made to Figures 1-10As shown, a single-degree-of-freedom composite-driven adjustable stiffness micro-motion platform includes a flexible micro-motion platform 3, a normal stress electromagnetic adjustable stiffness actuator 2, an upper cover plate 1, and a lower base plate 4. The normal stress electromagnetic adjustable stiffness actuator 2 is mounted on the flexible micro-motion platform 3, with the two in an intermediate layer. The upper cover plate 1 and the lower base plate 4 are located at the top and bottom layers, respectively. The upper cover plate 1 serves to prevent dust accumulation and provide protection, while the lower base plate 4 supports the instrument body, preventing friction between the flexible micro-motion platform and the base plate.

[0039] See 3 and Figure 7 The diagram shows the structure of a flexible micro-motion platform. A stage 303 is located at the center of the platform. A composite parallel guide flexible component 302 is located on the first opposite side of the stage 303. A piezoelectric ceramic actuator 5 is installed on one side of the second opposite side of the stage 303. The piezoelectric ceramic actuator 5 is connected to the stage 303 through a differential lever amplification flexible component 301.

[0040] Specifically, see attached Figure 3 Taking the view direction as an example and combining it with the appendix Figure 7 To explain, on the flexible micro-motion platform 3, composite parallel guide flexible components 302 are symmetrically arranged on the left and right sides of the stage 303. These components are composed of flexible leaf springs and are used to maintain the direction of motion and suppress parasitic displacement.

[0041] A mounting slot 305 for a normal stress electromagnetic adjustable stiffness actuator 2 is provided on the upper side of the stage 303. An armature mounting frame 304 is located on the upper side of the stage, at the bottom center of the mounting slot 305. The normal stress electromagnetic adjustable stiffness actuator 2 is connected to the flexible micro-motion platform 3 via an armature 8 mounted on the armature mounting frame 304. The armature mounting frame 304 ensures accurate relative positioning between the normal stress electromagnetic adjustable stiffness actuator 2 and the flexible micro-motion platform 3. A piezoelectric ceramic actuator mounting slot 306 is provided on the lower side of the stage 303 for mounting a piezoelectric ceramic actuator 5. Threaded holes are provided on the stage 303 for easy connection of external equipment.

[0042] In this embodiment, the piezoelectric ceramic actuator 5 is used to generate high-precision linear driving force, the flexible micro-motion platform 3 is used to transmit driving energy and guide, and the normal stress electromagnetic adjustable stiffness actuator 2 is used to generate adjustable negative stiffness, so as to realize real-time online adjustment of stiffness while ensuring precise micro-motion.

[0043] A channel is set on the flexible micro-motion platform on the right side of the piezoelectric ceramic actuator mounting slot 306. A T-shaped end is set at the channel to connect the input end of the differential lever amplification flexible component 301 and the output end of the piezoelectric ceramic actuator 5. A guide beam is set between the input end and the end of the differential lever amplification flexible component 301. The guide beam has the function of keeping the output force of the piezoelectric ceramic actuator horizontal and avoiding it from bearing shear force.

[0044] A differential lever amplification flexible component 301 is disposed on one side of one of the composite parallel guide flexible components 302, and its output end is connected to the stage 303 for amplifying the stroke of the piezoelectric ceramic actuator. The differential lever amplification flexible component 301 adopts a three-stage lever differential amplification, and its displacement amplification factor is 17 times.

[0045] The flexible micro-motion platform 3 has a piezoelectric ceramic actuator set screw mounting slot 307 on its left side. The piezoelectric ceramic actuator set screw mounting slot 307 is perpendicular to the composite parallel guide flexible component 302. The piezoelectric ceramic actuator set screw mounting slot 307 can be pre-tightened by the piezoelectric ceramic actuator set screw 14. Alternatively, the piezoelectric ceramic actuator set screw mounting slot 307 can be designed with a micro-head for mounting, allowing for direct pre-tightening using the micro-head.

[0046] Reference Figure 5 and Figure 6 The figure shows an exploded view of the normal stress electromagnetic adjustable stiffness actuator and a structural diagram of the upper and lower shells. The normal stress electromagnetic adjustable stiffness actuator 2 is set opposite to the piezoelectric ceramic actuator 5 on the flexible micro-motion platform 3.

[0047] The normal stress electromagnetic adjustable stiffness actuator has an upper outer shell 6, a lower outer shell 7, and an intermediate layer comprising a stator and a mover. The stator includes a T-shaped stator core 10 and two L-shaped stator cores 9. The mover, also known as the armature 8, is located in the central equilibrium position. The excitation coil 11 has a coil frame, which is wound around the central square shaft of the T-shaped stator core 10, generating negative stiffness at the armature 8. Both the mover and stator are made of soft magnetic materials with high permeability.

[0048] like Figure 5 As shown, an excitation coil 11 is provided on the middle winding square column of the T-shaped stator core 10, and L-shaped stator cores 9 are provided on both sides of the excitation coil 11. The first end of the L-shaped stator core 9 is connected to the T-shaped stator core 10, and the second end is provided with an air gap between it and the armature 8. The width of the air gap is 0.5mm. The armature 8 is located on the side of the excitation coil 11 away from the T-shaped stator core 10. The two L-shaped stator cores 9 are arranged opposite to each other on both sides of the armature 8. The normal stress electromagnetic adjustable stiffness actuator 2 has an overall axisymmetric structure.

[0049] The normal stress electromagnetic adjustable stiffness actuator 2 is connected to the armature mounting frame 304 on the flexible micro-motion platform 3 via the armature 8. The front and side of the armature mounting frame 304 are slotted to form a magnetic flux loop. The external lead of the excitation coil 11 is connected to a DC current to generate an electromagnetic field. The external lead of the coil is connected to the external stiffness control circuit through the housing wiring groove 15 to facilitate real-time stiffness adjustment.

[0050] The normal stress electromagnetic adjustable stiffness actuator 2 also includes an upper housing 6 and a lower housing 7 arranged opposite to each other. Both the upper housing 6 and the lower housing 7 are made of aluminum alloy. Figure 6 As shown in the view direction, the upper outer casing 6 and the lower outer casing 7 are respectively provided at the middle of the top of the upper outer casing 6 and the lower outer casing 7, and the upper outer casing armature slot 602 and the lower outer casing armature slot 702 are respectively provided at the bottom to connect the upper and lower ends of the armature.

[0051] The upper outer shell 6 and the lower outer shell 7 are also respectively provided with an upper outer shell flexible guide hinge 601 and a lower outer shell flexible guide hinge 701 connecting their respective armature slots. The hinges adopt a semi-circular notch form, with one end of each flexible guide hinge connected to the armature slot and the other end connected to the outer shell body. The flexible guide hinges are used to restrict the movement of the armature and reduce parasitic displacement caused by leakage flux.

[0052] The upper and lower outer shells are respectively provided with an upper outer shell stator core mounting slot 603 and a lower outer shell stator core mounting slot 703 to accommodate L-shaped and T-shaped stator cores. A set screw hole 705 is provided on one side of the stator core mounting slot of the lower outer shell 7. A set screw 12 is used in conjunction with the set screw hole 705 to tighten the L-shaped stator core 9, ensuring a tight fit between the stator cores and preventing magnetic leakage. Of course, a set screw hole can also be provided at a corresponding position on the upper outer shell.

[0053] Screw holes are provided on both sides of the guide groove, and the normal stress electromagnetic adjustable stiffness actuator 2 is connected as a whole by the housing fixing screws 13. Figure 4 As shown, after the upper and lower outer shells are connected, the upper outer shell wire groove 604 and the lower outer shell wire groove 704 are combined to form a wiring groove 15, which is used for wiring the excitation coil 11.

[0054] like Figure 10 As shown, it also includes an upper cover plate 1, which is located on the top of the flexible micro-motion platform 3. An opening is provided at the center of the upper cover plate 1 to accommodate the stage 303. The upper cover plate is rectangular, and its bottom edge is provided with multiple wire-locking grooves 101 and a wire-running groove 102 for wire locking and wire running.

[0055] Reference Figure 1 and Figure 2 It also includes a lower base plate 4, which is U-shaped and located at the bottom of the flexible micro-motion platform. Its maximum width does not cover the flexible components.

[0056] The single-degree-of-freedom composite drive adjustable stiffness micro-motion platform should be placed on a pneumatic platform. The upper cover plate, flexible micro-motion platform, and lower base plate are connected in sequence by platform fixing screws 16 and fixed on the pneumatic platform to reduce vibration and interference.

[0057] Furthermore, the displacement measurement of the single-degree-of-freedom composite drive adjustable stiffness micro-motion platform adopts a laser ruler, and its stage is equipped with mounting holes for placing calibration objects.

[0058] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A single-degree-of-freedom composite-driven adjustable stiffness micro-motion platform, characterized in that, include: The flexible micro-motion platform has a stage at its center, a composite parallel guide flexible component on the first opposite side of the stage, and a piezoelectric ceramic actuator installed on one side of the second opposite side of the stage. The piezoelectric ceramic actuator is connected to the stage through a differential lever amplification flexible component. The normal stress electromagnetic adjustable stiffness actuator is installed on the second opposite side of the stage and is positioned opposite to the piezoelectric ceramic actuator. It includes a T-shaped stator core, an excitation coil is provided on the winding post in the middle of the T-shaped stator core, and L-shaped stator cores are provided on both sides of the excitation coil. The first end of the L-shaped stator core is connected to the T-shaped stator core, and an air gap is provided between the second end and the armature. The normal stress electromagnetic adjustable stiffness actuator is connected to the flexible micro-motion platform through the armature, and the excitation coil is connected to an external lead to adjust the stiffness. The normal stress electromagnetic adjustable stiffness actuator also includes an upper shell and a lower shell arranged opposite to each other. A wire groove is provided at the middle of the top of the upper shell and the lower shell, and an armature groove is provided at the bottom to connect the upper and lower ends of the armature. The upper shell and the lower shell are also provided with flexible guide hinges that connect the armature grooves. The flexible guide hinges adopt the form of a semi-circular notch hinge. One end of the two flexible guide hinges is connected to the armature groove, and the other end is connected to the shell body. A piezoelectric ceramic actuator mounting slot is provided on one side of the second opposite side of the stage, and a differential lever amplification flexible component is provided on the first opposite side of the stage, employing a three-stage lever differential amplification.

2. The single-degree-of-freedom composite-driven adjustable stiffness micro-motion platform according to claim 1, characterized in that, The upper and lower outer shells are also provided with stator core mounting slots to accommodate L-shaped and T-shaped stator cores. The normal stress electromagnetic adjustable stiffness actuator has an axisymmetric structure.

3. The single-degree-of-freedom composite-driven adjustable stiffness micro-motion platform according to claim 2, characterized in that, Set screw holes are provided at the stator core mounting slots of the upper and lower outer shells, and set screws are used to tighten the L-shaped stator core.

4. The single-degree-of-freedom composite-driven adjustable stiffness micro-motion platform according to claim 1, characterized in that, The flexible micro-motion platform is provided with a piezoelectric ceramic actuator set screw mounting slot on one side.

5. The single-degree-of-freedom composite-driven adjustable stiffness micro-motion platform according to claim 1, characterized in that, The second opposite side of the stage is provided with a normal stress electromagnetic adjustable stiffness actuator mounting slot in the middle position. The flexible micro-motion platform is also provided with an armature mounting slot on one side of the normal stress electromagnetic adjustable stiffness actuator mounting slot for mounting an armature. The front and side of the armature mounting frame are slotted to form a magnetic flux circuit.

6. The single-degree-of-freedom composite-driven adjustable stiffness micro-motion platform according to claim 1, characterized in that, A guide beam is provided between the output end of the piezoelectric ceramic actuator and the input end of the differential lever amplification flexible component.

7. The single-degree-of-freedom composite-driven adjustable stiffness micro-motion platform according to claim 1, characterized in that, It also includes an upper cover plate, which is located on the top of the flexible micro-motion platform. An opening is provided at the center of the upper cover plate to accommodate the platform. The bottom edge of the upper cover plate is provided with a wire-holding groove and a wire-running groove.

8. The single-degree-of-freedom composite-driven adjustable stiffness micro-motion platform according to claim 7, characterized in that, It also includes a bottom plate, which is located at the bottom of the flexible micro-motion platform. The bottom plate is U-shaped and its maximum width does not cover the flexible components.

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