A linear displacement guide for a michelson interferometer

Abstract

This invention relates to Michelson interferometers, specifically to a linear displacement guiding device for Michelson interferometers, addressing the problem of poor load-bearing capacity in existing flexible support mechanisms for mirror displacement guiding devices. The invention includes a support frame, with a voice coil motor mounted on the vertical plate of the support frame. The rotor shaft of the voice coil motor coincides with the geometric center of the end face of the main motion platform in the flexible support mechanism. The main motion platform is connected to secondary motion platforms symmetrically arranged on both sides of the main motion platform via outer leaf springs at both ends. The mirror is located on the main motion platform, and its center of gravity lies in the vertical plane where the horizontal centerline of the main motion platform is located. Rigid constraint plates with gaps between them and the side walls are symmetrically arranged on both sides of the main motion platform. The rigid constraint plates are connected to the inner walls of the secondary motion platforms via inner leaf springs at both ends, and a fixed rigid body is provided at the bottom of the rigid constraint plates for connection with the horizontal plate of the support frame.

Description

Technical Field

[0001] This invention relates to Michelson interferometers, and more specifically to a linear displacement guiding device for Michelson interferometers. Background Technology

[0002] Time-modulated interferometric spectral imaging technology utilizes the amplitude-division interferometry principle. An interferometer generates a time-series of interference fringes around a target light source, and a Fourier transform is performed on the resulting interferogram to obtain the target's spectral information. It has wide applications in astronomy, medicine, climate monitoring, atmospheric science, and agricultural production.

[0003] As the core component of a time-modulated interferometric spectrometer, the most critical part of the Michelson interferometer is its precision mirror motion system. The travel distance of the mirrors in this system determines the spectral resolution of the entire interferometer, and the guiding accuracy of the mirrors determines the imaging quality of the interferograms. If the mirrors tilt or shift laterally along a non-motion direction during motion, the interferometry efficiency will be severely affected, or even no interferometry may occur. The uniformity of the mirror motion speed directly affects the signal-to-noise ratio and accuracy of the interferograms and the reconstructed spectra. Therefore, a high-precision displacement guiding device is essential for the Michelson interferometer.

[0004] In displacement guiding devices, the support mechanism for supporting the reflector has the greatest impact on displacement accuracy. Traditional reflector support mechanisms include linear bearing type, magnetic levitation type, air-bearing guide rail type, and flexible support type. Linear bearing type is a contact support and is rarely used in high-precision space instruments. Its main disadvantages are high wear and difficulty in maintaining lubrication. The sliding bearing used in the reflector drive system has very high machining precision requirements, which are generally difficult to achieve. Even if the machining precision is barely met, the precision of the sliding bearing will gradually decrease with increased wear. Magnetic levitation type refers to the motor shaft and reflector assembly being suspended in a state under the attraction of a set of electromagnets. It has the advantages of no friction and no wear, but it has disadvantages such as complex technology, high cost, large weight, and high power loss. Air-bearing guide rail type uses high-pressure gas to levitate and support the motor shaft and reflector assembly. Because it requires gas filling and storage equipment, which is large and complex, and has extremely high sealing requirements, it is rarely used. Current reflector displacement guide devices mostly adopt flexible support types, which have fewer components, simpler structure, and lower cost; they do not require additional intermediate transmission mechanisms, are frictionless during use, and therefore do not require lubrication; they can store elastic potential energy during movement, giving them a self-rebound reaction force, effectively resisting external vibration and impact, and are easy to match with other non-mechanical forces; when combined with laser position measurement modules and motion control execution modules, they can ensure the accuracy and uniformity of structural movement, overcoming the shortcomings of linear bearing, magnetic levitation, and air-bearing guide rail types mentioned above. However, most flexible support mechanisms still have the problem of poor load-bearing capacity, requiring a trade-off between motion stroke and structural stiffness during design. Summary of the Invention

[0005] The purpose of this invention is to solve the technical problem that the flexible support mechanism in the existing reflector displacement guide device has poor load-bearing capacity, so a trade-off must be made between motion stroke and structural stiffness in the design. The invention provides a linear displacement guide device for Michelson interferometers.

[0006] To address the technical problems existing in the prior art, the present invention provides the following technical solutions:

[0007] A linear displacement guide device for a Michelson interferometer includes a reflector and a bracket, and is characterized in that it also includes a flexible support mechanism and a drive mechanism.

[0008] The support includes a vertical plate and a horizontal plate disposed on one side of the bottom of the vertical plate;

[0009] The drive mechanism includes a voice coil motor, one end of which is fixed to a vertical plate, and the moving part of the voice coil motor is connected to a flexible support mechanism.

[0010] The flexible support mechanism includes a main motion platform and two secondary motion platforms symmetrically arranged on both sides of the main motion platform. The main motion platform and the two secondary motion platforms are connected by two outer leaf springs at both ends of the main motion platform to form a cuboid structure. The reflector is installed on the upper surface of the main motion platform. One end of the main motion platform is connected to the mover of the voice coil motor, and the axis of the mover coincides with the geometric center of the end face of the main motion platform. The center of gravity of the reflector is located in the vertical plane where the center line of the main motion platform along the horizontal direction is located. A constraint structure is provided between the main motion platform and each secondary motion platform. The constraint structure includes rigid constraint plates symmetrically arranged on both sides of the main motion platform. There is a gap between the rigid constraint plates and the side wall of the main motion platform. The rigid constraint plates are connected to the inner wall of the secondary motion platform by inner leaf springs at both ends. A fixed rigid body for connecting with the horizontal plate is provided at the bottom of the rigid constraint plate.

[0011] Furthermore, a transition platform is provided between the reflector and the main motion platform. The cross-section of the transition platform is a T-shaped structure with an outward convexity at the bottom. The width of the outward convexity is not greater than the width of the main motion platform. The outward convexity is connected to the main motion platform. The reflector is installed at the center of the upper surface of the transition platform. The center line of the transition platform in the horizontal direction is parallel to the center line of the main motion platform in the horizontal direction and is located in the same vertical plane.

[0012] Furthermore, the gap size is 1 mm.

[0013] Furthermore, the flexible support mechanism is an integral structure made of aluminum alloy. The inner and outer leaf springs are processed by electrical discharge machining or wire cutting, and the main motion platform, secondary motion platform, rigid constraint plate, and fixed rigid body are machined by mechanical milling.

[0014] Furthermore, the outer leaf spring has rounded corners at the right-angle connection points with the main motion platform and the secondary motion platform, and the inner spring plate also has rounded corners at the right-angle connection points with the secondary motion platform and the rigid constraint plate.

[0015] Furthermore, L-shaped support plates are provided on both sides of the horizontal plate. The vertical section of the support plate is connected to the side of the horizontal plate. A docking hole is provided on the fixed rigid body. The horizontal section of the support plate extends away from the horizontal plate and has a connecting hole for connecting with the docking hole.

[0016] Furthermore, the main motion platform has a diamond-shaped weight-reducing cavity at its center, and the transfer platform has a rectangular weight-reducing cavity at its center.

[0017] Furthermore, the voice coil motor is a cylindrical moving magnet voice coil motor.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] (1) The present invention provides a linear displacement guiding device for a Michelson interferometer, comprising a reflector, a bracket, a flexible support mechanism, and a driving mechanism; the flexible support mechanism comprises a main motion platform and secondary motion platforms symmetrically arranged on both sides thereof, the reflector being disposed on the upper surface of the main motion platform, the main and secondary motion platforms being connected by outer leaf springs, and constraint structures being provided on both sides of the main motion platform, including rigid constraint plates symmetrically arranged on both sides of the main motion platform, the rigid constraint plates having gaps with the side walls of the main motion platform to avoid affecting the movement of the main motion platform, the rigid constraint plates being fixed to the inner walls of the secondary motion platforms by inner leaf springs disposed at both ends thereof, and a fixed rigid body connected to the bracket being provided at the bottom of the rigid constraint platform, the voice coil motor of the driving mechanism being connected to one end of the main motion platform to provide driving force for it, thus, displacement transmission is achieved by the deformation of the leaf springs distributed in series, which has the advantages of frictionless, wear-free, and high precision, and the deformation direction of the leaf springs is horizontal, the load of the device only exerts a vertical downward pressure on the flexible support mechanism by the weight of the load itself, the downward pressure does not act on the deformation direction of the leaf springs, this arrangement maximizes the load-bearing capacity and movement stroke of the device.

[0020] (2) In the linear displacement guide device for Michelson interferometer provided by the present invention, the reflector is mounted on the main motion platform through the adapter. In this way, when facing reflectors with different mounting hole specifications, different adapters can be used instead of replacing the overall flexible support mechanism. The operation is simple and the cost is low.

[0021] (3) The flexible support mechanism in the linear displacement guide device for Michelson interferometer provided by the present invention is an integral structure and is made of aluminum alloy. Compared with the spliced ​​structure, the integral structure has a smaller overall error and higher structural strength, which is beneficial to improving the overall load-bearing capacity of the device.

[0022] (4) In the linear displacement guide device for Michelson interferometer provided by the present invention, the outer leaf spring is provided with rounded corners at the right-angle connection between the main motion platform and the secondary motion platform, and the inner spring is also provided with rounded corners at the right-angle connection between the secondary motion platform and the rigid constraint plate. This can effectively reduce stress concentration at the right-angle connection and extend the service life of the device.

[0023] (5) The linear displacement guiding device for Michelson interferometer provided by the present invention has a weight reduction cavity at the center of the main motion platform and the adapter plate. Without affecting the normal function, the weight of the device is reduced, which is beneficial to improving the load-bearing capacity of the device.

[0024] (6) In the linear displacement guide device for Michelson interferometer provided by the present invention, the gap between the rigid constraint plate and the side wall of the main motion platform is 1mm. This design can ensure that the rigid constraint plate will not interfere with the main motion platform during movement, and can also effectively increase the length of the inner plate spring to achieve the largest possible displacement. Attached Figure Description

[0025] Figure 1 This is a three-dimensional structural schematic diagram of an embodiment of the linear displacement guiding device for a Michelson interferometer according to the present invention.

[0026] Figure 2 This is a three-dimensional structural diagram of the flexible support mechanism in an embodiment of the linear displacement guiding device for a Michelson interferometer according to the present invention;

[0027] Figure 3 This is a top view of the flexible support mechanism in an embodiment of the linear displacement guide device for a Michelson interferometer according to the present invention;

[0028] Figure 4 This is a schematic diagram of the transition platform in an embodiment of the linear displacement guiding device for a Michelson interferometer according to the present invention;

[0029] Figure 5 This is a schematic diagram of the support structure in an embodiment of the linear displacement guiding device for a Michelson interferometer according to the present invention;

[0030] Figure 6 This is a simplified schematic diagram of the flexible support mechanism in motion in an embodiment of the linear displacement guide device for a Michelson interferometer according to the present invention.

[0031] Figure 7 This is a schematic diagram of the voice coil motor in an embodiment of the linear displacement guiding device for a Michelson interferometer according to the present invention.

[0032] The annotations in the attached figures are explained as follows:

[0033] 1-Bracket, 11-Vertical plate, 12-Horizontal plate, 121-Support plate; 2-Voice coil motor, 21-Stator, 22-Motor; 3-Reflector, 4-Transfer platform, 41-Rectangular weight reduction cavity; 5-Flexible support mechanism, 51-Main motion platform, 511-Rhomboid weight reduction cavity, 52-Outer leaf spring, 53-Inner leaf spring, 54-Rigid constraint plate, 55-Secondary motion platform, 56-Fixed rigid body. Detailed Implementation

[0034] The present invention will be further described below with reference to the accompanying drawings and exemplary embodiments.

[0035] Reference Figures 1-7The linear displacement guiding device for a Michelson interferometer of the present invention includes a bracket 1, a reflector 3, a flexible support mechanism 5, and a voice coil motor 2 for driving the flexible support mechanism 5 to perform reciprocating linear motion. The bracket 1 includes a vertical plate 11 and a horizontal plate 12 disposed on one side of the bottom of the vertical plate 11. The vertical plate 11 and the horizontal plate 12 form a right angle structure. L-shaped support plates 121 are also disposed on both sides of the horizontal plate 11. The vertical section of the support plate 121 is connected to the side of the horizontal plate 12, and the horizontal section extends in a direction away from the horizontal plate 12 and has a connecting hole thereon for connecting with the flexible support mechanism 5.

[0036] like Figure 7 As shown, the voice coil motor 2 includes a stator 21 and a mover 22. One end of the stator 21 is fixed to the vertical plate 11, and the mover 22 is connected to the flexible support mechanism 5, thus driving the flexible support mechanism 5 to perform reciprocating linear motion. The voice coil motor 2 adopts a cylindrical moving magnet type, avoiding the problems of repeated bending of the coil leads and poor heat dissipation during operation of ordinary moving coil motors, effectively extending the life of the device.

[0037] The structure of the flexible support mechanism 5 is as follows: Figure 2 , Figure 3As shown, the system includes a main motion platform 51 located at the center. One end of the main motion platform 51 is connected to the mover 22 of the voice coil motor 2, and the axis of the mover 22 coincides with the geometric center of the end face of the main motion platform 51. Secondary motion platforms 55 are arranged on both sides of the main motion platform 51. The two secondary motion platforms 55 are connected to the main motion platform 51 through two outer leaf springs 52 at both ends of the main motion platform 51. Thus, the main motion platform 51, the two secondary motion platforms 55 and the outer leaf springs 52 form a cuboid structure. A cavity exists between the main motion platform 51 and each secondary motion platform 55. Constraint structures are installed within these cavities to compensate for coupled displacement in non-motion directions. The constraint structures include rigid constraint plates 54 symmetrically arranged on both sides of the main motion platform 51. The rigid constraint plates 54 are connected to the inner walls of the secondary motion platforms 55 via inner leaf springs 53 at both ends. To avoid affecting the movement of the main motion platform 51, a 1mm gap exists between the rigid constraint plates 54 and the side walls of the main motion platform 51. This prevents friction between the main motion platform 51 and the rigid constraint plates 54 during horizontal reciprocating motion. Furthermore, the 1mm gap allows for an effective increase in the length of the inner leaf springs 53 without affecting the normal movement of the main motion platform 51, thereby maximizing displacement and improving spectral resolution. The outer leaf spring 52 and the inner leaf spring 53 have different lengths: the outer leaf spring 52 is 63mm long, and the inner leaf spring 53 is 59mm long. Both the inner and outer leaf springs are 30mm wide and 1mm thick. A fixed rigid body 56 is provided at the bottom of the rigid constraint plate 54, and a mating hole is provided on it for bolt connection with the connecting hole on the support plate 121. After the connection is made, the two support plates 121 raise the entire flexible support mechanism 5, so that the bottom of the main motion platform 51 is away from the horizontal plate 12, preventing friction during the movement and affecting the accuracy.

[0038] To reduce stress concentration at right-angle connections of the flexible support mechanism 5, a 0.5mm radius fillet is provided at the right-angle connections between the outer leaf spring 52 and the main motion platform 51 and the secondary motion platform 55, and a 0.5mm radius fillet is also provided at the right-angle connections between the inner spring 53 and the secondary motion platform 55 and the rigid constraint plate 54. To further improve the load-bearing capacity of the flexible support mechanism 5, the entire flexible support mechanism 5 adopts a one-piece structure and is made of aluminum alloy. Flexible components, namely the inner leaf spring 53 and the outer leaf spring 52, are machined using electrical discharge machining (EDM) or wire cutting. Rigid components, namely the main motion platform 51, the secondary motion platform 55, the rigid constraint plate 54, and the fixed rigid body 56, are machined using milling. After machining, processing stress is removed, thus avoiding assembly errors, improving accuracy, and resulting in a stronger load-bearing capacity for the one-piece structure.

[0039] The reflector 3 is connected to the main motion platform 51 via a transition platform 4. The transition platform 4 has a T-shaped cross-section with an outward convex bottom. The convex part connects to the main motion platform 51. By replacing different transition platforms 4, different reflectors 3 can be accommodated, improving the applicability of the device. The T-shaped structure also separates the portion of the transition platform 4 used for mounting the reflector 3 from the inner and outer leaf springs, preventing mutual friction during movement. The reflector 3 is mounted at the center of the upper surface of the transition platform 4, so that the center of gravity of the reflector 3 is located at the center of the transition platform 4. Furthermore, the horizontal centerline of the transition platform 4 is parallel to the horizontal centerline of the main motion platform 51 and lies in the same vertical plane. Thus, the vertical projections of the center of gravity of the reflector 3, the center of the transition platform 4, and the center of the main motion platform 51 will be on the same horizontal axis, preventing additional torque in the vertical direction during movement and thus ensuring displacement accuracy. The width of the convex part is no greater than the width of the main motion platform 51 to prevent friction with the inner and outer leaf springs and the rigid constraint plate 54. The entire flexible support mechanism 5 is arranged horizontally. The gravity of the reflector 3 and the adapter 4 is distributed along the width direction of each inner and outer leaf spring, that is, the non-leaf spring deformation direction. The thrust of the voice coil motor 2 is along the thickness direction of each inner and outer leaf spring, that is, the leaf spring deformation direction. In this way, the gravity of the reflector 3 and the adapter 4 is perpendicular to the deformation direction, so it will not affect the linear displacement and maximize the load-bearing capacity and movement stroke of the flexible support mechanism 5.

[0040] To further reduce the weight of the device and improve its load-bearing capacity, a rectangular weight-reducing cavity 41 is provided in the center of the transfer platform 4, and a rhomboid weight-reducing cavity 511 is provided in the center of the main motion platform 51. The weight is reduced without affecting the function, and the device can support a heavier reflector 3, thereby improving its load-bearing capacity.

[0041] In use, the reflector 3 is installed onto the main motion platform 51 via the adapter 4. Then, the voice coil motor 2 is started. The outer leaf spring 52 and the inner leaf spring 53 will undergo elastic deformation under the push of the voice coil motor 2. The main motion platform 51 will also produce a strict linear motion under the constraint of the inner and outer leaf springs. Because the adjacent outer leaf spring 52 and inner leaf spring 53 are connected in series, that is, the inner leaf spring 53 is not connected to the main motion platform 51 and the rigid constraint plate 54 is fixed to the bracket 1, when the main motion platform 51 moves linearly, the following will occur: Figure 6In the deformation scenario shown, the inner leaf spring 53 and the outer leaf spring 52 undergo elastic deformation simultaneously and in opposite directions. In this case, the displacement of the main motion platform 51 will be equal to the deformation of the inner leaf spring 53 plus the deformation of the outer leaf spring 52. If the inner leaf spring 53 is connected to the main motion platform 51 and the secondary motion platform 55 is fixed on the support 1 to form a parallel distribution, the deformation directions of the inner and outer leaf springs are the same, and the deformation amounts of the inner and outer leaf springs are the same. The displacement of the main motion platform 51 is equal to the deformation amount of either the inner leaf spring 53 or the outer leaf spring 52. Compared to the parallel distribution, the series distribution of the inner and outer leaf springs of the flexible support mechanism 5 in this embodiment can make the displacement distance of the main motion platform 51 larger.

[0042] The embodiments described above are merely illustrative of specific implementations of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A linear displacement guiding device for a Michelson interferometer, comprising a reflector (3) and a support (1), characterized in that: It also includes a flexible support mechanism (5) and a drive mechanism; The bracket (1) includes a vertical plate (11) and a horizontal plate (12) disposed on one side of the bottom of the vertical plate (11); The driving mechanism includes a voice coil motor (2), one end of which is fixed on a vertical plate (11), and the moving part (22) of the voice coil motor (2) is connected to a flexible support mechanism (5). The flexible support mechanism (5) includes a main motion platform (51) and two secondary motion platforms (55) symmetrically arranged on both sides of the main motion platform (51). The main motion platform (51) and the two secondary motion platforms (55) are connected by two outer leaf springs (52) at both ends of the main motion platform (51) to form a cuboid structure. The reflector (3) is installed on the upper surface of the main motion platform (51). One end of the main motion platform (51) is connected to the mover (22) of the voice coil motor (2), and the axis of the mover (22) coincides with the geometric center of the end face of the main motion platform (51). The reflector (3) The center of gravity of the main motion platform (51) is located in the vertical plane where the center line of the main motion platform (51) is located in the horizontal direction. There is a constraint structure between the main motion platform (51) and each secondary motion platform (55). The constraint structure includes rigid constraint plates (54) symmetrically arranged on both sides of the main motion platform (51). There is a gap between the rigid constraint plate (54) and the side wall of the main motion platform (51). The rigid constraint plate (54) is connected to the inner wall of the secondary motion platform (55) by inner leaf springs (53) arranged at both ends. The bottom of the rigid constraint plate (54) is provided with a fixed rigid body (56) for connecting with the horizontal plate (12).

2. The linear displacement guiding device for a Michelson interferometer according to claim 1, characterized in that: A transition platform (4) is provided between the reflector (3) and the main motion platform (51). The cross-section of the transition platform (4) is a T-shaped structure with an outward convex bottom. The width of the outward convexity is not greater than the width of the main motion platform (51). The outward convexity is connected to the main motion platform (51). The reflector (3) is installed at the center of the upper surface of the transition platform (4). The center line of the transition platform (4) along the horizontal direction is parallel to the center line of the main motion platform (51) along the horizontal direction and is located in the same vertical plane.

3. The linear displacement guiding device for a Michelson interferometer according to claim 2, characterized in that: The gap size is 1 mm.

4. The linear displacement guiding device for a Michelson interferometer according to claim 3, characterized in that: The flexible support mechanism (5) is an integral structure made of aluminum alloy. The inner leaf spring (53) and the outer leaf spring (52) are processed by electrical discharge machining or wire cutting. The main motion platform (51), the secondary motion platform (55), the rigid constraint plate (54) and the fixed rigid body (56) are processed by mechanical milling.

5. The linear displacement guiding device for a Michelson interferometer according to claim 4, characterized in that: The outer leaf spring (52) is provided with rounded corners at the right-angle connection with the main motion platform (51) and the secondary motion platform (55), and the inner spring plate (53) is also provided with rounded corners at the right-angle connection with the secondary motion platform (55) and the rigid constraint plate (54).

6. The linear displacement guiding device for a Michelson interferometer according to any one of claims 1-5, characterized in that: The horizontal plate is provided with L-shaped support plates (121) on both sides. The vertical section of the support plate (121) is connected to the side of the horizontal plate (12). The fixed rigid body (56) is provided with a docking hole. The horizontal section of the support plate (121) extends away from the horizontal plate (12) and is provided with a connecting hole for connecting with the docking hole.

7. The linear displacement guiding device for a Michelson interferometer according to claim 2, characterized in that: The main motion platform (51) has a diamond-shaped weight reduction cavity (511) at its center, and the transfer platform (4) has a rectangular weight reduction cavity (41) at its center.

8. The linear displacement guiding device for a Michelson interferometer according to claim 1, characterized in that: The voice coil motor (2) is a cylindrical moving magnet voice coil motor.

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