A novel three-degree-of-freedom translational actuator

Abstract

This invention relates to a novel three-degree-of-freedom translational actuator. The invention includes a support base; a drive base; an XY-axis drive mechanism, including an X-axis electromagnetic actuation unit and a Y-axis electromagnetic actuation unit respectively connected to the drive base; and a Z-axis drive mechanism, including a Z-axis electromagnetic actuation unit connected to the drive base. Both the X-axis and Y-axis electromagnetic actuation units include: a first mover assembly, including a first mover core and a first permanent magnet; and two first stator assemblies, including a first stator core and a first stator coil, which drive the controlled object to translate along the XY directions. The Z-axis electromagnetic actuation unit includes: a second mover assembly, including a second mover core and a second permanent magnet; and two second stator assemblies, including a second stator core and a second stator coil, which drive the controlled object to translate along the Z-direction. This invention enables stable movement and precise position control of the controlled object in the X, Y, and Z directions.

Description

Technical Field

[0001] This invention relates to the field of precision servo drive control technology, and in particular to a novel three-degree-of-freedom translational actuator. Background Technology

[0002] In micro-displacement motion control within the optical field, micro-scanning can improve system resolution. Based on the different driving elements used in the micro-scanning process, it can be categorized into motor-driven micro-scanning, piezoelectric ceramic actuator-driven micro-scanning, and electromagnetic actuator-driven micro-scanning. Motor-driven methods suffer from low control bandwidth; piezoelectric ceramic actuator-driven methods suffer from short stroke. Electromagnetic actuator-driven methods can simultaneously satisfy high control bandwidth and relatively large motion stroke, making them a more ideal choice for micro-displacement scanning control in large field-of-view situations. Advances in optical scanning technology have driven the advancement of multi-degree-of-freedom micro-displacement drive control technology. Three-degree-of-freedom micro-displacement drive control technology, compared to existing single-degree-of-freedom and two-degree-of-freedom micro-displacement drive control technologies, offers greater advantages in scanning positioning and focus adjustment.

[0003] Most existing micro-displacement actuation mechanisms achieve three-degree-of-freedom motion by orthogonally combining and superimposing three single-degree-of-freedom micro-displacement modules, which suffers from low system integration and large size. Moreover, in different optical applications, it is usually necessary to maintain the hollow structural feature of the micro-displacement actuation mechanism to ensure the passage of light, and there is a lack of mature three-degree-of-freedom micro-displacement actuation mechanism solutions. Summary of the Invention

[0004] Therefore, this invention provides a novel three-degree-of-freedom translational actuator, which can realize stable motion and precise position control of the controlled object in the X, Y, and Z directions, and has the characteristics of high integration, fast response speed, and large stroke.

[0005] To solve the above-mentioned technical problems, the present invention provides a novel three-degree-of-freedom translational actuator, comprising: Support base; A drive unit is movably connected to the support unit and is connected to a controlled object. The XY drive mechanism includes an X-axis electromagnetic actuation unit and a Y-axis electromagnetic actuation unit that are respectively connected to the drive base; Z-axis drive mechanism, including Z-axis electromagnetic actuation unit connected to the drive base; Both the X-axis electromagnetic actuation unit and the Y-axis electromagnetic actuation unit include: The first mover assembly includes a first mover core and a first permanent magnet connected to opposite sides of the first mover core. Two first stator assemblies are symmetrically arranged on opposite sides of the first moving core. Each first stator assembly includes a first stator core and a first stator coil bonded to the side of the first stator core opposite to the first moving core. The first stator coil is energized in the magnetic field generated by the first permanent magnet, causing the first moving assembly to be subjected to force. By changing the direction of the current in the first stator coil, the output force direction of the first moving assembly can be changed. The first moving assembly drives the drive base to drive the controlled object to translate along the XY direction. The Z-axis electromagnetic actuation unit includes: The second mover assembly includes a second mover core and a second permanent magnet connected to opposite sides of the second mover core; Two second stator assemblies are symmetrically arranged on opposite sides of the second mover core. Each second stator assembly includes a second stator core and a second stator coil bonded to the side of the second stator core opposite to the second mover core. The second stator coil is energized in the magnetic field generated by the second permanent magnet, causing the second mover assembly to be subjected to force. By changing the direction of the current in the second stator coil, the output force direction of the second mover assembly can be changed. The second mover assembly drives the drive base to drive the controlled object to translate along the Z direction.

[0006] In one embodiment of the present invention, the drive base includes a mover connector, an upper mounting plate, an upper elastic plate connected to the upper mounting plate, a lower elastic plate connected to the mover connector, a mover center seat whose upper and lower ends are respectively connected to the upper elastic plate and the second mover core, and a support column connected between the mover connector and the upper mounting plate. The second mover core is connected to the lower elastic plate, and the upper and lower ends of the support column are respectively connected to the upper mounting plate and the lower elastic plate.

[0007] In one embodiment of the present invention, the two opposing end edges of the mover connector are respectively connected to the first mover assembly of the X-direction electromagnetic actuation unit and the Y-direction electromagnetic actuation unit.

[0008] In one embodiment of the present invention, the two X-axis electromagnetic actuation units and the two Y-axis electromagnetic actuation units are orthogonally distributed.

[0009] In one embodiment of the present invention, the support base includes a base and an upper mounting base connected to the base. The upper end face of the upper mounting base is provided with an X-axis linear guide rail and an X-axis sliding plate slidably connected to the X-axis linear guide rail. The upper end face of the X-axis sliding plate is provided with a Y-axis linear guide rail, and the upper mounting plate is slidably connected to the Y-axis linear guide rail.

[0010] In one embodiment of the present invention, a receiving cavity is formed between the base and the upper mounting base to accommodate the X-axis electromagnetic actuation unit, the Y-axis electromagnetic actuation unit and the Z-axis electromagnetic actuation unit. The two first stator assemblies of each of the X-axis electromagnetic actuation unit and the Y-axis electromagnetic actuation unit are respectively connected to the base and the upper mounting base, and the two second stator assemblies of the Z-axis electromagnetic actuation unit are respectively connected to the base and the upper mounting base.

[0011] In one embodiment of the present invention, the first permanent magnet is a rectangular permanent magnet, the first moving core has a left-right symmetrical structure, and two first permanent magnets are symmetrically arranged on the top and bottom of the first moving core along the left-right symmetrical cross-section of the first moving core, but with opposite magnetic pole directions.

[0012] In one embodiment of the present invention, the second permanent magnet is a ring permanent magnet, and four second permanent magnets are symmetrically arranged along the center on the two opposite sides of the second moving core. The four second permanent magnets can generate four magnetic field loops that are symmetrical in the left and right directions, and these four magnetic field loops are symmetrical about the initial position of the second moving core.

[0013] In one embodiment of the present invention, the controlled object is a lens assembly, including a lens cover and a lens body mounted in the moving center seat via the lens cover.

[0014] In one embodiment of the present invention, both the upper elastic sheet and the lower elastic sheet are spring sheets.

[0015] The technical solution of the present invention has the following advantages over the prior art: The novel three-degree-of-freedom translational actuator described in this invention abandons the existing layered structure of X, Y, and Z three-degree-of-freedom modules, allowing the actuator mover components in the X, Y, and Z directions to directly drive the controlled object to move. It has good real-time response characteristics and can realize stable motion and precise position control of the controlled object in the X, Y, and Z directions. It has fewer transmission components, a smaller overall mover mass, and improves response speed and control bandwidth. The symmetrical design of the Z-direction iron core and upper and lower springs not only strengthens the Z-direction output but also improves the stability of the system. Attached Figure Description

[0016] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0017] Figure 1 This is a schematic diagram of the overall structure of the three-degree-of-freedom translational actuator of the present invention.

[0018] Figure 2 This is a schematic cross-sectional view of the overall structure of the three-degree-of-freedom translational actuator of the present invention.

[0019] Figure 3 This is a schematic diagram of the drive seat structure of the present invention.

[0020] Figure 4 This is a schematic diagram of the structure of the X-axis electromagnetic actuation unit and the Y-axis electromagnetic actuation unit of the present invention.

[0021] Figure 5 This is a schematic diagram of the support structure of the present invention.

[0022] Figure 6 This is a schematic diagram of the Z-axis electromagnetic actuation unit structure of the present invention.

[0023] Figure 7 This is a cross-sectional view of the Z-axis electromagnetic actuation unit of the present invention.

[0024] Figure 8 This is a cross-sectional view of the Z-axis drive mechanism of the present invention in the X direction.

[0025] Figure 9 This is a power output analysis diagram of the X-axis electromagnetic actuation unit and the Y-axis electromagnetic actuation unit of the present invention.

[0026] Figure 10 This is a force analysis diagram of the Z-axis electromagnetic actuation unit of the present invention.

[0027] Explanation of reference numerals on the accompanying drawings: 1. Support base; 11. Base; 12. Upper mounting base; 13. X-axis linear guide; 14. X-axis slide plate; 15. Y-axis linear guide; 2. Drive seat; 21. Mover connector; 22. Upper mounting plate; 23. Upper elastic plate; 24. Lower elastic plate; 25. Mover center seat; 26. Support column; 3A. X-axis electromagnetic actuation unit; 3B. Y-axis electromagnetic actuation unit; 31. First mover core; 32. First permanent magnet; 33. First stator core; 34. First stator coil; 35. Coil hub; 4. Z-axis electromagnetic actuation unit; 41. Second mover core; 42. Second permanent magnet; 42a. Inner annular permanent magnet; 42b. Outer annular permanent magnet; 43. Second stator core; 44. Second stator coil; 45. Core retaining ring; 46. Bolt; 47. Cross-head round screw; 51. Lens cap; 52. Lens body; 53. Cap fastening screws. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0029] In this invention, when directions (up, down, left, right, front, and back) are described, it is only for the convenience of describing the technical solution of this invention, and does not indicate or imply that the technical features referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0030] In this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," "exceeding," etc., are understood to exclude the stated number; "above," "below," "within," etc., are understood to include the stated number. In the description of this invention, the terms "first" and "second" are used only to distinguish technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0031] In this invention, unless otherwise explicitly defined, the terms "setting," "installing," and "connecting" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium; a fixed connection, a detachable connection, or an integrally formed connection; a mechanical connection, an electrical connection, or a connection capable of mutual communication; or the internal connection of two components or the interaction between two components. Those skilled in the art can reasonably determine the specific meaning of the above terms in this invention based on the specific content of the technical solution.

[0032] Reference Figures 1 to 10 As shown, a novel three-degree-of-freedom translational actuator of the present invention includes: Support 1; Drive seat 2 is movably connected to support seat 1 and is connected to the controlled object; The XY drive mechanism includes an X-axis electromagnetic actuation unit 3A and a Y-axis electromagnetic actuation unit 3B, which are respectively connected to the drive base 2. Z-axis drive mechanism, including Z-axis electromagnetic actuation unit 4 connected to the drive base 2; The X-axis electromagnetic actuation unit 3A and the Y-axis electromagnetic actuation unit 3B both include: The first mover assembly includes a first mover core 31 and a first permanent magnet 32 ​​connected to opposite sides of the first mover core 31. Two first stator assemblies are symmetrically arranged on opposite sides of the first moving core 31. Each first stator assembly includes a first stator core 33 and a first stator coil 34 bonded to the side of the first stator core 33 opposite to the first moving core 31. The first stator coil 34 is energized in the magnetic field generated by the first permanent magnet 32, causing the first moving assembly to be subjected to force. By changing the direction of the current in the first stator coil 34, the output force direction of the first moving assembly can be changed. The first moving assembly drives the drive base 2 to drive the controlled object to translate along the XY direction. The Z-axis electromagnetic actuation unit 4 includes: The second mover assembly includes a second mover core 41 and a second permanent magnet 42 connected to opposite sides of the second mover core 41. Two second stator assemblies are symmetrically arranged on opposite sides of the second mover core 41. Each second stator assembly includes a second stator core 43 and a second stator coil 44 bonded to one side of the second stator core 43 opposite to the second mover core 41. The magnetic field generated by the second permanent magnet 42 of the second stator coil 44 is energized, causing the second mover assembly to be subjected to force. By changing the direction of the current in the second stator coil 44, the output force direction of the second mover assembly can be changed. The second mover assembly drives the drive base 2 to drive the controlled object to translate along the Z direction.

[0033] Reference Figure 3 As shown, the drive base 2 includes a mover connector 21, an upper mounting plate 22, an upper elastic plate 23 connected to the upper mounting plate 22, a lower elastic plate 24 connected to the mover connector 21, a mover center seat 25 whose upper and lower ends are respectively connected to the upper elastic plate 23 and the second mover core 41, and a support column 26 connected between the mover connector 21 and the upper mounting plate 22. The second mover core 41 is connected to the lower elastic plate 24, and the upper and lower ends of the support column 26 are respectively connected to the upper mounting plate 22 and the lower elastic plate 24. With the above configuration, the second mover core 41 of the Z-axis electromagnetic actuation unit 4 generates Z-axis movement. Since the second mover core 41 is fixed on the lower elastic plate 24, the lower elastic plate 24 is subjected to force and generates a small deformation, thereby driving the mover center seat 25 to move in the Z-axis, and simultaneously driving the upper spring plate to move, ensuring the stability of the mover center seat 25 in the two-dimensional translational direction.

[0034] In some embodiments, both the upper elastic sheet 23 and the lower elastic sheet 24 are spring sheets.

[0035] Reference Figure 3As shown, the two sets of opposite end edges on the mover connector 21 are respectively connected to the first mover assembly of the X-direction electromagnetic actuation unit 3A and the Y-direction electromagnetic actuation unit 3B.

[0036] In this embodiment, the two X-axis electromagnetic actuation units 3A and the two Y-axis electromagnetic actuation units 3B are orthogonally distributed; the first stator assembly also includes a coil hub 35 connected to the side of the first stator core 33 opposite to the first mover core 31, and the first stator coil 34 is wound on the coil hub 35.

[0037] Reference Figure 5 As shown, the support base 1 includes a base 11 and an upper mounting base 12 connected to the base 11. The upper surface of the upper mounting base 12 is provided with an X-axis linear guide rail 13 and an X-axis sliding plate 14 slidably connected to the X-axis linear guide rail 13. The upper surface of the X-axis sliding plate 14 is provided with a Y-axis linear guide rail 15, and the upper mounting plate 22 is slidably connected to the Y-axis linear guide rail 15. The X-axis linear guide rail 13 and the Y-axis linear guide rail 15 are fixedly connected by the X-axis sliding plate 14 in a double-layer superposition manner. The linear guide rails mainly serve to guide in the X and Y directions and provide support in the Z direction.

[0038] Specifically, a cavity is formed between the base 11 and the upper mounting base 12 to accommodate the X-axis electromagnetic actuation unit 3A, the Y-axis electromagnetic actuation unit 3B, and the Z-axis electromagnetic actuation unit 4. The two first stator assemblies of each of the X-axis electromagnetic actuation unit 3A and the Y-axis electromagnetic actuation unit 3B are respectively connected to the base 11 and the upper mounting base 12, and the two second stator assemblies of the Z-axis electromagnetic actuation unit 4 are respectively connected to the base 11 and the upper mounting base 12.

[0039] Specifically, the first permanent magnet 32 ​​is a rectangular permanent magnet, and the first moving core 31 has a symmetrical structure. Two first permanent magnets 32 are symmetrically arranged above and below the first moving core 31 along the symmetrical cross-section of the first moving core 31, but with opposite magnetic pole directions. (Refer to...) Figure 9 As shown, under the action of the first permanent magnet 32 ​​and the energized first stator coil 34, the first permanent magnet generates a counterclockwise magnetic field; in the top-down view, the energized first stator coil 34 generates a counterclockwise current. According to the Ampere force principle, there is a rightward electromagnetic force F1 on the first stator coil 34, which generates an interaction force F2 on the first moving core 31, driving the first moving core 31 and the first permanent magnet 32 ​​to move. By changing the direction of the current, a force in the opposite direction can be obtained, realizing reciprocating translational motion in one dimension. The principle is the same in the other direction.

[0040] Specifically, the second permanent magnet 42 is a ring-shaped permanent magnet. Four second permanent magnets 42 are symmetrically arranged along the center on the two opposite sides of the second moving core 41. The four second permanent magnets 42 can generate four magnetic field loops that are symmetrical in the left and right directions. Furthermore, these four magnetic field loops are symmetrical about the initial position of the second moving core 41.

[0041] Reference Figure 10 The diagram shows a cross-sectional view of the Z-axis electromagnetic actuation unit 4 in the X-axis. The analysis focuses on the magnetic field loop on the left side. Four annular permanent magnets are symmetrically distributed, with two at the top and two at the bottom. For the bottom annular permanent magnets, the innermost magnet has its S pole at the bottom and its N pole at the top, while the outermost magnet has its N pole at the bottom and its S pole at the top, with the magnetic field lines rotating counterclockwise. For the top annular permanent magnets, the innermost magnet has its N pole at the bottom and its S pole at the top, while the outermost magnet has its S pole at the bottom and its N pole at the top, with the magnetic field lines rotating clockwise. This arrangement of permanent magnets creates two symmetrical magnetic field loops between the top and bottom pairs of annular permanent magnets. When the second stator coil 44 is not energized, the magnetic forces exerted on the second stator core 43 by the two pairs of annular permanent magnets are equal in magnitude and opposite in direction, effectively canceling each other out and keeping the second mover assembly stationary.

[0042] When the second stator coil 44 is energized with a counter-clockwise current in the view direction, taking the left-side iron core as an example, the current direction points out of the paper, generating a counter-clockwise magnetic field loop. This loop is in the same direction as the magnetic field loop of the lower annular permanent magnet. Therefore, the magnetic field strength formed by the lower annular permanent magnet is strengthened, while the magnetic field strength of the upper annular permanent magnet is partially canceled out, resulting in a weaker magnetic field. Consequently, the net magnetic force on the second mover iron core 41 is downward. The magnetic field loop on the right side is symmetrical to that on the left, ultimately still causing the second mover iron core 41 to experience a downward magnetic force. By analogy, it can be seen that in the entire annular Z-axis actuator, the second mover iron core 41 experiences a downward force, controlling the downward movement of the mover center seat 25. Changing the current direction of the second stator coil 44 can change the direction of the force on the second mover assembly. Considering that the excitation coil and the mover core form a negative stiffness system, annular permanent magnets are installed on both sides of the second mover core 41 and are symmetrically distributed. At the same time, upper and lower spring plates are installed on the upper and lower sides of the mover center seat 25. The overall structure reduces the negative stiffness of the system while increasing the stability of the second mover core 41.

[0043] In this embodiment, refer to Figure 8As shown, the controlled object is a lens assembly, including a lens cap 51 and a lens body 52 mounted within the mover center seat 25 via the lens cap 51. This invention enables the mover assembly of the actuator in the X, Y, and Z directions to directly drive the controlled object to move, exhibiting good real-time response characteristics and achieving stable movement and precise position control of the lens assembly in the X, Y, and Z directions.

[0044] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A three degree of freedom translational actuator, characterized by, include: Support base; A drive unit is movably connected to the support unit and is connected to a controlled object. The XY drive mechanism includes an X-axis electromagnetic actuation unit and a Y-axis electromagnetic actuation unit that are respectively connected to the drive base; Z-axis drive mechanism, including Z-axis electromagnetic actuation unit connected to the drive base; Both the X-axis electromagnetic actuation unit and the Y-axis electromagnetic actuation unit include: The first mover assembly includes a first mover core and a first permanent magnet connected to opposite sides of the first mover core. Two first stator assemblies are symmetrically arranged on opposite sides of the first moving core. Each first stator assembly includes a first stator core and a first stator coil bonded to the side of the first stator core opposite to the first moving core. The first stator coil is energized in the magnetic field generated by the first permanent magnet, causing the first moving assembly to be subjected to force. By changing the direction of the current in the first stator coil, the output force direction of the first moving assembly can be changed. The first moving assembly drives the drive base to drive the controlled object to translate along the XY direction. The Z-axis electromagnetic actuation unit includes: The second mover assembly includes a second mover core and a second permanent magnet connected to opposite sides of the second mover core; Two second stator assemblies are symmetrically arranged on opposite sides of the second moving core. Each second stator assembly includes a second stator core and a second stator coil bonded to the side of the second stator core opposite to the second moving core. The second stator coil is energized in the magnetic field generated by the second permanent magnet, causing the second moving core to be subjected to force. By changing the direction of the current in the second stator coil, the output force direction of the second moving core can be changed. The second moving core drives the drive base to drive the controlled object to translate along the Z direction. The second permanent magnet is a ring-shaped permanent magnet. Four second permanent magnets are symmetrically arranged along the center on the two opposite sides of the second moving core. The four second permanent magnets can generate four magnetic field loops that are symmetrical in the left and right directions. Furthermore, these four magnetic field loops are symmetrical about the initial position of the second moving core.

2. A three degree of freedom translational actuator according to claim 1, wherein, The drive base includes a mover connector, an upper mounting plate, an upper elastic plate connected to the upper mounting plate, a lower elastic plate connected to the mover connector, a mover center seat whose upper and lower ends are respectively connected to the upper elastic plate and the second mover core, and a support column connecting the mover connector and the upper mounting plate. The second mover core is connected to the lower elastic plate, and the upper and lower ends of the support column are respectively connected to the upper mounting plate and the lower elastic plate.

3. A three degree of freedom translational actuator according to claim 2, wherein, The two opposing end edges of the mover connector are respectively connected to the first mover assembly of the X-axis electromagnetic actuation unit and the Y-axis electromagnetic actuation unit.

4. A three degree of freedom translational actuator according to claim 3, wherein, The two X-axis electromagnetic actuation units and the two Y-axis electromagnetic actuation units are orthogonally distributed.

5. A three-degree-of-freedom translational actuator according to claim 2, characterized in that, The support base includes a base and an upper mounting base connected to the base. The upper end face of the upper mounting base is provided with an X-axis linear guide rail and an X-axis sliding plate slidably connected to the X-axis linear guide rail. The upper end face of the X-axis sliding plate is provided with a Y-axis linear guide rail, and the upper mounting plate is slidably connected to the Y-axis linear guide rail.

6. A three-degree-of-freedom translational actuator according to claim 5, characterized in that, A cavity is formed between the base and the upper mounting base to accommodate the X-axis electromagnetic actuation unit, the Y-axis electromagnetic actuation unit, and the Z-axis electromagnetic actuation unit. The two first stator assemblies of each of the X-axis electromagnetic actuation unit and the Y-axis electromagnetic actuation unit are respectively connected to the base and the upper mounting base, and the two second stator assemblies of the Z-axis electromagnetic actuation unit are respectively connected to the base and the upper mounting base.

7. A three-degree-of-freedom translational actuator according to claim 1, characterized in that, The first permanent magnet is a rectangular permanent magnet, and the first moving core has a left-right symmetrical structure. The two first permanent magnets are symmetrically arranged on the top and bottom of the first moving core along the left-right symmetrical cross-section of the first moving core, but the magnetic poles are opposite.

8. A three-degree-of-freedom translational actuator according to claim 2, characterized in that, The controlled object is a lens assembly, including a lens cover and a lens body installed in the moving part center seat via the lens cover.

9. A three-degree-of-freedom translational actuator according to claim 2, characterized in that, Both the upper and lower elastic sheets are springs.

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