Electromagnetic direct drive six-degree-of-freedom decoupled flexible nano-positioning platform

Abstract

The application relates to an electromagnetic direct-drive six-freedom-degree decoupling flexible nano-positioning platform, which comprises a bottom plate (1), a moving platform (2) located above the bottom plate (1), and a plurality of horizontal motion branches and a plurality of vertical motion branches located between the bottom plate (1) and the moving platform (2). Compared with the prior art, the application has eight motion branches in parallel, four horizontal distributed motion branches drive the moving platform to generate front-back, left-right movement and rotation on a horizontal plane, and four vertical motion branches drive the moving platform to generate vertical movement, pitching rotation and left-right swing. In addition, flexible spherical hinges are added at the ends of the motion branches as decoupling devices to reduce the coupling in the input-output and each freedom direction.

Description

Technical Field

[0001] This invention relates to the field of micro-nano positioning technology, specifically to an electromagnetically driven six-degree-of-freedom decoupled flexible nano-positioning platform. Background Technology

[0002] Six-degree-of-freedom (DOF) nanopositioning platforms are widely used in many fields such as optics, biomedicine, microscopy, and chip manufacturing. Examples include template substrate alignment and leveling devices for nanoimprint lithography and six-degree-of-freedom micromanipulation robots for fiber optic docking. Existing six-degree-of-freedom nanopositioning platforms include two types of structures: macro-motion and micro-motion. Macro-scale vibration and motion positioning platforms generally use rigid series or parallel mechanisms driven by motors or hydraulics, but often suffer from low resolution due to friction issues. Submicron-scale vibration and motion positioning platforms use flexible hinges and piezoelectric actuators, but the output displacement of piezoelectric ceramic actuators is small, often between 0.01 mm and 0.1 mm, which cannot meet the requirements for large stroke displacements.

[0003] Chinese patent CN113125094 A discloses a six-degree-of-freedom micro-vibration device based on a flexible mechanism, which achieves six-degree-of-freedom movement through micro-vibration. Chinese patent CN109502542A relates to a multi-degree-of-freedom nano-positioning platform based on a compliant parallel mechanism. This platform employs redundant drive with nanometer precision, but its structure is overly complex, and the use of piezoelectric ceramic actuators results in a relatively small platform stroke. Summary of the Invention

[0004] The purpose of this invention is to overcome at least one of the defects in the prior art by providing an electromagnetically driven six-degree-of-freedom decoupled flexible nanopositioning platform. This positioning platform has eight parallel motion chains: four horizontally distributed motion chains drive the platform to move forward and backward, left and right, and rotate in the horizontal plane; four vertical motion chains drive the platform to move vertically, pitch and rotate, and swing left and right. Furthermore, this invention incorporates flexible ball joints at the ends of the motion chains as decoupling devices to reduce input / output coupling and coupling in each degree of freedom direction.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] Based on this, the designers proposed an electromagnetically driven six-degree-of-freedom decoupled flexible nanopositioning platform. This nanopositioning platform has a simple and symmetrical structure and is directly driven by a voice coil motor driver. It can achieve complete decoupling in each degree of freedom direction, making its positioning accuracy higher and its control more convenient.

[0007] An electromagnetically driven six-degree-of-freedom decoupled flexible nanopositioning platform is provided. The positioning platform includes a base plate and a moving platform located on the base plate, as well as multiple horizontal motion branches and multiple vertical motion branches located between the base plate and the moving platform.

[0008] The horizontal motion chain includes a horizontal chain mounting bracket, a horizontal chain connecting plate, a decoupling mechanism, and a transmission assembly;

[0009] One end of the horizontal branch mounting bracket is fixed to the base plate, and the other end is fixedly connected to the transmission component; one end of the decoupling mechanism is fixedly connected to the end of the transmission component away from the horizontal branch mounting bracket, and the other end is fixedly connected to the horizontal branch connecting plate; the end of the horizontal branch connecting plate away from the decoupling mechanism is fixedly connected to the moving platform.

[0010] The vertical motion chain includes a vertical chain mounting bracket, a decoupling mechanism, and a transmission assembly;

[0011] One end of the vertical branch mounting bracket is fixed to the base plate, and the other end is fixedly connected to the transmission component; one end of the decoupling mechanism is fixedly connected to the transmission component away from the vertical branch mounting bracket, and the other end is fixedly connected to the moving platform.

[0012] More specifically, the base plate is connected to the moving platform through multiple horizontal and vertical motion chains to ensure that there are no gaps between the various components of the positioning platform and to achieve high-precision movement of the moving platform.

[0013] Furthermore, the transmission assembly includes a rigid rectangular frame, a motor mounting base, a motor mounting block, and a voice coil motor; the rectangular frame has a motor mounting base at one end and a motor mounting block at the opposite end; the voice coil motor is located between the motor mounting base and the motor mounting block. More specifically, the voice coil motor has a magnet assembly and a coil assembly; the magnet assembly at one end of the voice coil motor is connected to the motor mounting base, and the voice coil motor coil assembly is connected to the motor mounting block.

[0014] Furthermore, there are four horizontal motion branches and four vertical motion branches.

[0015] Furthermore, the horizontal motion branches are rotationally symmetrical about the center of the moving platform; they are located at the four corners of the base plate 1. The area of ​​the figure formed by the intersection of the axes of the horizontal motion branches is greater than 0.

[0016] Furthermore, the vertical motion branches are rotationally symmetrical about the center of the moving platform; the center point of each vertical motion branch is located at the same height.

[0017] More specifically, the voice coil motors, which work in conjunction with the horizontal motion chains, drive the horizontal motion chains to move the platform horizontally (forward / backward, left / right) or vertically (rotate). The voice coil motors, which work in conjunction with the vertical motion chains, drive the vertical motion chains to move the platform vertically (pitch / rotate) or oscillate. Based on this design, the voice coil motors, through four horizontal and four vertical motion chains, drive the end effector to achieve six degrees of freedom of motion in space. The multiple horizontal and vertical motion chains are rotationally symmetrical around the center of the platform, resulting in a symmetrical overall structure that improves symmetry, flexibility, and accuracy of the motion.

[0018] Furthermore, the horizontal motion branch and the vertical motion branch operate in parallel.

[0019] Furthermore, the horizontal branch mounting bracket is an L-shaped rigid connecting plate, and both the horizontal branch connecting plate and the motor mounting base are rigid connecting plates.

[0020] Furthermore, the vertical branch mounting bracket is a W-shaped rigid connecting plate with an included angle of 90°.

[0021] Furthermore, the decoupling mechanism is a flexible ball joint.

[0022] Furthermore, the flexible ball joint is a long-stroke flexible ball joint.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] (1) The present invention designs a novel flexible nano-positioning platform driven by eight parallel motion branches. The platform uses eight parallel motion branches to achieve planar three-degree-of-freedom and spatial three-degree-of-freedom motion through four sets of horizontal branches and four sets of vertical branches respectively.

[0025] (2) The present invention adopts a large-stroke spherical hinge based on a flexible beam and an overall symmetrical structure to reduce the coupling between the input and output of the driver and in each degree of freedom, thereby improving the travel range and decoupling performance of the platform.

[0026] (3) The present invention uses electromagnetic actuators such as voice coil motors to directly drive parallel flexible mechanisms to achieve six-degree-of-freedom nano-positioning, which has the advantages of simple structure, large stroke, easy processing and assembly and low cost. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the positioning platform in Example 1;

[0028] Figure 2 This is a schematic diagram of the horizontal motion branch of the positioning platform in Example 1;

[0029] Figure 3This is a schematic diagram of the vertical motion branch of the positioning platform in Example 1;

[0030] Figure 4 This is a schematic diagram of the decoupling mechanism of the positioning platform in Example 1;

[0031] The numbers in the diagram indicate: 1-base plate; 2-moving platform; 3-vertical branch mounting bracket; 4-horizontal branch mounting bracket; 5-horizontal branch connecting plate; 6-rectangular frame; 7-motor mounting base block; 8-motor mounting block; 9-voice coil motor; 10-decoupling mechanism. Detailed Implementation

[0032] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0033] Example 1

[0034] like Figure 1-4 As shown, an electromagnetic direct-drive six-degree-of-freedom decoupled flexible nanopositioning platform includes a base plate 1, a moving platform 2, four vertical branch mounting brackets 3, four horizontal branch mounting brackets 4, four horizontal branch connecting plates 5, eight rectangular frames 6, eight motor mounting base blocks 7, eight motor mounting blocks, eight decoupling mechanisms 10, and eight voice coil motors 9, wherein the four vertical motion branches and the four horizontal motion branches are composed of the above-mentioned mechanisms.

[0035] Referring to the attached drawings, the vertical branch mounting bracket 3 and the horizontal branch mounting bracket 4 are disposed between the base plate 1 and the moving platform 2. The number of multiple moving branch mounting brackets is equal to the number of corresponding moving branches, and they correspond one-to-one. This embodiment includes four horizontal moving branches and four vertical moving branches, for a total of eight moving branches. Each horizontal moving branch includes a horizontal branch mounting bracket 4, a rectangular frame 6, a motor mounting base block 7, a motor mounting block 8, a voice coil motor 9, and a decoupling mechanism 10. One end of the horizontal moving branch is connected and fixed to the rectangular frame 6 and the horizontal branch mounting bracket 4. The other end of the horizontal moving branch is connected to the horizontal branch connecting plate 5 via the decoupling mechanism 10. The other end of the horizontal branch connecting plate 5 is connected and fixed to the moving platform 2. The voice coil motor 9 in the horizontal moving branch has a magnet assembly and a coil assembly. The magnet assembly at one end of the voice coil motor 9 is connected to the motor mounting base block 7, and the voice coil motor coil assembly is connected to the motor mounting block 8. The motor mounting block 8 is connected to the rectangular frame 6. The rectangular frame 6 is externally connected to the decoupling mechanism 10. The other end of the decoupling mechanism 10 is connected to the horizontal branch connecting plate 5, which is connected to the moving platform 2. The entire horizontal motion branch is connected and fixed in the horizontal plane through the horizontal branch mounting bracket 4 and the horizontal branch connecting plate 5. It is horizontally distributed. Each horizontal motion branch contains the same structure and is rotationally symmetrical about the center of the moving base plate in the same horizontal plane, located at the four corners of the base plate 1. The four vertical motion branches include the vertical branch mounting bracket 3, the rectangular frame 6, the motor mounting base block 7, the motor mounting block 8, the voice coil motor 9, and the decoupling mechanism 10. One end of the vertical motion branch is connected and fixed to the vertical branch mounting bracket 3 through its rectangular frame 6, and the other end of the vertical motion branch is connected and fixed to the moving platform 2 through the decoupling mechanism 10. The voice coil motor 9 in the vertical motion chain has a magnet assembly and a coil assembly. One end of the magnet assembly of the voice coil motor 9 is connected to the motor mounting base block 7, and the voice coil motor coil assembly is connected to the motor mounting block 8. The motor mounting base block 7 is connected to the rectangular frame 6, and the motor mounting block 8 is also connected to the rectangular frame 6. The rectangular frame 6 is externally connected to the decoupling mechanism 10, and the other end of the decoupling mechanism 10 is connected to the moving platform 2. The four vertical motion chains are vertically arranged and rotate symmetrically around the center of the moving base plate. The four vertical motion chains are vertically distributed on the base plate 1, with the center point of each vertical motion chain at the same height. The four vertical motion chains are located at the four corners. In this embodiment, the area of ​​the figure formed by the intersection of the axes of the four horizontal motion chains is greater than 0.

[0036] Referring to the attached diagram, the voice coil motor 9, which works in conjunction with the horizontal motion chain, drives the horizontal motion chain to cause the moving platform to move forward and backward, left and right, or rotate vertically. Specifically, when two diagonally opposite horizontal motion chains work simultaneously, the moving platform 2 can be displaced in the forward and backward or left and right directions; when only one horizontal motion chain is worked, the moving platform 2 can be rotated vertically. The desired motion can be generated by controlling the number and different positions of the horizontal motion chains. The voice coil motor 9, which works in conjunction with the vertical motion chain, drives the vertical motion chain to cause the moving platform to move vertically, pitch, rotate, or oscillate. Specifically, four vertical motion chains are controlled simultaneously so that they move together to produce vertical movement of the moving platform 2. When two diagonally opposite vertical motion chains work simultaneously, the moving platform 2 can be pitched, rotated, or oscillated.

[0037] Referring to the attached diagram, the four horizontal motion chains and the four vertical motion chains can work in parallel. By controlling the voice coil motors 9 in different motion chains, the movement of the corresponding motion chains can be achieved, thus achieving the desired working purpose.

[0038] Referring to the attached diagram, the decoupling mechanism 10 is a large-stroke flexible spherical hinge. The flexible spherical hinge consists of only one component. After being driven by the driving element, it can obtain the displacement of the end of the component relative to the reference coordinate system entirely by its own deformation.

[0039] Example 2

[0040] refer to Figure 1 An electromagnetically driven six-degree-of-freedom decoupled flexible nanopositioning platform is disclosed. The positioning platform includes a base plate 1 and a moving platform 2 located on the base plate 1, as well as multiple horizontal motion branches and multiple vertical motion branches located between the base plate 1 and the moving platform 2. The horizontal motion branches and vertical motion branches work in parallel.

[0041] refer to Figure 2 In this embodiment, there are four horizontal motion branches, which are rotationally symmetrical about the center of the moving platform 2; the area of ​​the figure formed by the intersection of the axes of the horizontal motion branches is greater than 0. Each horizontal motion branch includes a horizontal branch mounting bracket 4, a horizontal branch connecting plate 5, a decoupling mechanism 10, and a transmission assembly. One end of the horizontal branch mounting bracket 4 is fixed to the base plate 1, and the other end is fixedly connected to the transmission assembly. One end of the decoupling mechanism 10 is fixedly connected to the end of the transmission assembly away from the horizontal branch mounting bracket 4, and the other end is fixedly connected to the horizontal branch connecting plate 5. The end of the horizontal branch connecting plate 5 away from the decoupling mechanism 10 is fixedly connected to the moving platform 2. The horizontal branch mounting bracket 4 is an L-shaped rigid plate. The vertical branch mounting bracket 3 is a W-shaped rigid plate with an included angle of 90°.

[0042] refer to Figure 3There are four vertical motion chains; each vertical motion chain is rotationally symmetrical about the center of the moving platform 2; the center point of each vertical motion chain is located at the same height. Each vertical motion chain includes a vertical chain mounting bracket 3, a decoupling mechanism 10, and a transmission assembly; one end of the vertical chain mounting bracket 3 is fixed to the base plate 1, and the other end is fixedly connected to the transmission assembly; one end of the decoupling mechanism 10 is fixedly connected to the transmission assembly away from the vertical chain mounting bracket 3, and the other end is fixedly connected to the moving platform 2.

[0043] refer to Figure 2 , Figure 3 The transmission assembly includes a rectangular frame 6, a motor mounting base 7, a motor mounting block 8, and a voice coil motor 9; the rectangular frame 6 has a motor mounting base 7 at one end and a motor mounting block 8 at the opposite end; the voice coil motor 9 is located between the motor mounting base 7 and the motor mounting block 8.

[0044] refer to Figure 4 The decoupling mechanism 10 is a large-stroke flexible spherical hinge. The flexible spherical hinge consists of only one component. After being driven by the driving element, it can obtain the displacement of the end of the component relative to the reference coordinate system by relying entirely on its own deformation.

[0045] Working principle:

[0046] In this embodiment, the voice coil motor 9, which works in conjunction with the horizontal motion chain, drives the horizontal motion chain to move the platform 2 horizontally (forward / backward, left / right translation or vertical rotation); the voice coil motor 9, which works in conjunction with the vertical motion chain, drives the vertical motion chain to move the platform 2 vertically (pitch, rotate or oscillate). Based on the above design, the voice coil motor 9 drives the end effector to generate six degrees of freedom of motion in space through four horizontal motion chains and four vertical motion chains; the multiple horizontal motion chains and multiple vertical motion chains are rotationally symmetrical around the center of the platform 2, making the overall structure symmetrical, improving symmetry, and enhancing the flexibility and accuracy of the motion.

[0047] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. An electromagnetically driven six-degree-of-freedom decoupled flexible nanopositioning platform, characterized in that, The positioning platform includes a base plate (1) and a moving platform (2) located on the base plate (1), as well as multiple horizontal motion branches and multiple vertical motion branches located between the base plate (1) and the moving platform (2); The horizontal motion chain includes a horizontal chain mounting bracket (4), a horizontal chain connecting plate (5), a decoupling mechanism (10), and a transmission assembly; One end of the horizontal branch mounting bracket (4) is fixed on the base plate (1), and the other end is fixedly connected to the transmission assembly; one end of the decoupling mechanism (10) is fixedly connected to the end of the transmission assembly away from the horizontal branch mounting bracket (4), and the other end is fixedly connected to the horizontal branch connecting plate (5); the end of the horizontal branch connecting plate (5) away from the decoupling mechanism (10) is fixedly connected to the moving platform (2). The vertical motion chain includes a vertical chain mounting bracket (3), a decoupling mechanism (10), and a transmission assembly; One end of the vertical branch mounting bracket (3) is fixed on the base plate (1), and the other end is fixedly connected to the transmission assembly; one end of the decoupling mechanism (10) is fixedly connected to the transmission assembly away from the vertical branch mounting bracket (3), and the other end is fixedly connected to the moving platform (2); The transmission assembly includes a rectangular frame (6), a motor mounting base (7), a motor mounting block (8), and a voice coil motor (9); the rectangular frame (6) has a motor mounting base (7) at one end and a motor mounting block (8) at the opposite end; the voice coil motor (9) is located between the motor mounting base (7) and the motor mounting block (8); Multiple horizontal motion chains and multiple vertical motion chains work in parallel. By controlling the voice coil motors (9) in different motion chains, the movement of the corresponding motion chains can be achieved. The decoupling mechanism (10) is a large-stroke flexible spherical hinge. The flexible spherical hinge consists of only one component. After being driven by the driving element, it can obtain the displacement of the end of the component relative to the reference coordinate system by relying entirely on its own deformation.

2. The electromagnetic direct-drive six-degree-of-freedom decoupled flexible nanopositioning platform according to claim 1, characterized in that, There are four horizontal motion branches and four vertical motion branches.

3. The electromagnetic direct-drive six-degree-of-freedom decoupled flexible nanopositioning platform according to claim 2, characterized in that, The horizontal motion chain is rotationally symmetrical around the center of the moving platform (2); the area of ​​the figure formed by the intersection of the axes of the horizontal motion chain is greater than 0.

4. The electromagnetic direct-drive six-degree-of-freedom decoupled flexible nanopositioning platform according to claim 2, characterized in that, The vertical motion chain is rotationally symmetrical around the center of the platform (2); the center point of each vertical motion chain is located at the same height.

5. The electromagnetic direct-drive six-degree-of-freedom decoupled flexible nanopositioning platform according to claim 1, characterized in that, The horizontal motion branch and the vertical motion branch work in parallel.

6. The electromagnetic direct-drive six-degree-of-freedom decoupled flexible nanopositioning platform according to claim 1, characterized in that, The horizontal branch mounting bracket (4) is an L-shaped plate.

7. The electromagnetic direct-drive six-degree-of-freedom decoupled flexible nanopositioning platform according to claim 1, characterized in that, The vertical branch mounting bracket (3) is a W-shaped plate with an included angle of 90°.

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