[0037] The specific embodiments of the present invention will be described in further detail below in conjunction with the drawings and embodiments. The following examples are used to illustrate the present invention, but not to limit the scope of the present invention.
[0038] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inner", "Outer", "Clockwise", "Counterclockwise", "Axial", The orientation or positional relationship indicated by "radial", "circumferential", "X-axis", "Y-axis", etc. are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, not It indicates or implies that the pointed device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.
[0039] In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.
[0040] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and other terms should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection , Or integrated; it can be mechanically connected, or it can be electrically connected or can communicate with each other; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal communication of two components or the interaction relationship between two components, Unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0041] figure 1 with figure 2 A preferred embodiment of a measurement system for the displacement and rotation angle of a micro-nano control platform according to the present invention is shown. Such as figure 1 As shown, the micro-nano manipulation platform includes a platform base 5 and a displacement platform 4 located on the platform base 5. The measurement system includes: a first laser interferometer 1 and a second laser interferometer located on a first axis (ie, Y axis) In the instrument 2, the central axis of the emission hole of the first laser interferometer 1 and the central axis of the emission hole of the second laser interferometer 2 are collinear. The measurement system also includes a third laser interferometer 3 located on a second axis (that is, the X axis) perpendicular to the first axis, the third laser interferometer 3 and the first laser interferometer 1 and the second laser interferometer 2 is located in the same horizontal plane, and the central axis of the emission hole of the third laser interferometer 3 is perpendicular to the central axis of the emission hole of the first laser interferometer 1. The measurement system also includes an optical assembly 6 configured in a cross shape on the displacement platform 4. The optical assembly 6 includes a first right-angle lens portion corresponding to the first laser interferometer 1, and the first right-angle lens portion includes a first right angle. A mirror surface and a second right-angle mirror surface, and the incident light emitted by the first laser interferometer 1 is parallel to the incident light rays reflected by the first right-angle mirror surface and the second right-angle mirror surface of the first right-angle mirror portion. In this embodiment, the initial incident angle of the incident light emitted by the first laser interferometer 1 to the first right-angle mirror surface of the first right-angle mirror portion is 45°. The optical assembly also includes a second right-angle lens portion corresponding to the second laser interferometer 2. The second right-angle lens portion includes a first right-angle mirror surface and a second right-angle mirror surface, and the incident light emitted by the second laser interferometer 2 corresponds to the incident light. The light rays reflected by the first right-angle mirror surface and the second right-angle mirror surface of the second right-angle lens part are parallel. In this embodiment, the incident light rays emitted by the second laser interferometer 2 are incident on the first right angle of the second right-angle lens part. The initial incident angle of the mirror is 45°. The optical assembly also includes a third right-angle lens portion corresponding to the third laser interferometer 3. The third right-angle lens portion includes a first right-angle mirror surface and a second right-angle mirror surface, and the incident light emitted by the third laser interferometer 3 is consistent with the incident light. The light rays reflected by the first right-angle mirror surface and the second right-angle mirror surface of the third right-angle lens part are parallel. In this embodiment, the initial incident angle of the incident light emitted by the second laser interferometer 3 to the first right-angle mirror surface of the third right-angle lens part is 45°.
[0042] The measurement system for the displacement and rotation angle of the micro-nano control platform provided by the present invention can realize the displacement measurement in the Y direction through two laser interferometers on the Y axis, and can indirectly calculate the rotation angle of the micro-nano control platform (specific calculation method It will be described below), the displacement measurement in the X direction is realized through the third laser interferometer on the X axis, so that the measurement system can realize the displacement and angle measurement with multiple degrees of freedom in space, which well overcomes the problems of the existing detection devices. Limitations, to meet the real-time measurement feedback of linear displacement and angular displacement with multiple degrees of freedom in space. In addition, the measurement system has a simple structure and high measurement accuracy.
[0043] Specifically, such as image 3 As shown, the optical assembly 6 includes an optical assembly base 601 arranged on the displacement platform 1, four clamping slots configured in a cross shape are arranged on the optical assembly base 601, and a glass sheet 602 is arranged in each clamping slot. , Wherein the two glass sheets 602 close to the third laser interferometer 3 are coated with reflective films on both sides, and the glass sheet 602 far away from the third laser interferometer 3 and close to the first laser interferometer 1 faces the first laser interferometer One side of 1 is coated with a reflective film, and the glass sheet 602 away from the third laser interferometer 3 and close to the second laser interferometer 2 is coated with a reflective film on the side facing the second laser interferometer 2. Among them, the two glass sheets close to the first laser interferometer 1 are constructed as the first right-angle lens part, the two glass sheets close to the second laser interferometer 2 are constructed as the second right-angle lens part, and the third laser interferometer 13 The two glass sheets are configured as a third right-angle lens portion.
[0044] Preferably, the optical assembly further includes two fixed brackets 603 on the optical assembly base 601 and two movable brackets 604 that can move in the X direction, one of the fixed brackets 603 is attached to the two adjacent to the first laser interferometer 1, respectively. On two glass sheets, the other fixed bracket 603 is attached to the two glass sheets close to the second laser interferometer 2, and one of the movable brackets 604 abuts on the two glass sheets close to the third laser interferometer 3, and the other The movable bracket 604 abuts on the two glass sheets away from the third laser interferometer 3, and the cross sections of the fixed bracket 603 and the movable bracket 604 are both isosceles right-angled shapes. A bolt 605 is provided at the outer end of the movable bracket 604, and a threaded hole matched with the bolt 605 is provided on the optical assembly base 601. When the bolt head is screwed, the bolt rod abuts on the movable bracket 604 to make the movable bracket 604 slides along the X direction, thereby fixing the corresponding glass sheet between the corresponding movable support 603 and the fixed support 604.
[0045] The invention also discloses a method for measuring the displacement and rotation angle of the micro-nano control platform, which includes the following steps:
[0046] S1: Control the movement of the micro-nano platform (such as Figure 5 (Shown) is decomposed into the translational movement of the displacement platform 4 along the X axis (such as Image 6 Shown), translational movement along the Y axis (such as Figure 7 Shown) and the rotational movement around the center point of the platform (such as Figure 8 As shown), let the translation distance of the displacement platform 4 along the X axis be a 1 , The translation distance along the Y axis is a 2 And the rotation angle around the center of the platform is θ;
[0047] S2: The first optical path difference Y of the Y axis measured by the first laser interferometer 1 11; The second optical path difference Y of the Y axis measured by the second laser interferometer 2 22; The optical path difference X of the X axis measured by the third laser interferometer 3 11;
[0048] S3: The optical path difference Y received by the first laser interferometer 1 due to the translational movement of the displacement platform 4 along the first axis is calculated by the following formula 1 , The optical path difference Y received by the first laser interferometer 1 due to the rotation of the displacement platform around the center point of the platform 2 And the translation distance a along the Y axis 2 (Such as Figure 8 Shown);
[0049] Y 11 =Y 1 +Y 2 ,
[0050] Y 22 =-Y 1 +Y 2 ,
[0051] Y 1 = 2a 2;
[0052] S4: Set in the rotation around the center point of the platform, such as Figure 8 As shown, the distance between the first reflection point B of the first right-angle lens portion before the rotation of the displacement platform 4 and the first reflection point E of the first right-angle lens portion after the rotation of the displacement platform 4 is m, The distance between the second reflection point C of the right-angle lens part and the second reflection point F of the first right-angle lens part after the displacement platform 4 rotates is n, then α=m/n, and L is known 0 Is the distance between the incident light AB and the outgoing light CD of the first right-angle lens part before the displacement platform 4 moves (e.g. Figure 7 Shown), the rotation angle θ of the displacement platform 4 is calculated by the following formula:
[0053]
[0054]
[0055] in Figure 7 Medium, L 0 Is the distance between the incident light AB and the outgoing light CD of the first right-angle lens part when the displacement platform 4 is not moving; L 1 Is the distance between the incident light AE and the outgoing light FG of the first right-angle lens part after the displacement platform 4 moves in translation along the X axis; a 1 Is the translation distance of the displacement platform 4 along the X axis, L 1 -L 0 =DG=2×a 1 Therefore, the displacement of the micro-nano control platform along the X axis can be obtained by measuring the movement distance of the emitted light.
[0056] When the displacement platform 4 moves along the Y axis, the change in the optical path difference in the X direction is zero, that is, when moving along the Y axis, the output of the first laser interferometer 1 and the second laser interferometer 2 does not change.
[0057] When the displacement platform 4a moves along the Y axis, the first laser interferometer 1 receives the optical path difference Y due to the translational movement of the displacement platform 4a along the Y axis. 1 , The optical path difference Y received by the first laser interferometer 1 due to the rotation of the displacement platform around the center point of the platform 2 And the translation distance a along the Y axis 2 (Such as Figure 8 Shown), then Y 1 , Y 2 And a 2 Meet the following formula;
[0058] Y 11 =Y 1 +Y 2 ,
[0059] Y 22 =-Y 1 +Y 2 ,
[0060] Y 1 = 2a 2;
[0061] Before and after the rotation of the displacement platform 4b around the center point of the platform, when the direction and position of the incident light ray AB remain unchanged, the direction and position of the outgoing light CD does not change either.
[0062] in Figure 8 In the middle, the horizontal line KN is made through K point, the extension line of GF is made through F and the horizontal line through K point intersects at point N.
[0063] (1) Suppose the rotation angle of the displacement platform 4 is θ. When the rotation angle θ is 0°, the incident light is AB, the outgoing light is CD, the incident angle of the incident light is 45°, and the exit angle of the outgoing light CD is also 45 °, therefore EB//CG.
[0064] (2) When the rotation angle θ is not 0°, the incident light is AE, the outgoing light is FG, and the incident angle of the incident light is 45°+θ, at this time ∠KEF=45°-θ, in the right angle ΔEKF, ∠ KEF=45°-θ, ∠EKF=90°, we can get ∠EFK=45°+θ.
[0065] Figure 8 Among them, ∠FKN=45°-θ, ∠GHM=∠EFK=45°+θ, ∠KFN=∠GFM=45°+θ. So ∠KNF=180°-∠FKN-∠KFN=90°. GF's extension line FN//EB is parallel, so GF//EB.
[0066] The distance from AB to CD is BC=L1. The distance from FG to EB is EG, ∠GEF=90°-∠BEK-∠KEF=2θ, and EG and GF are perpendicular, so EG=EF×cos2θ, where
[0067] EF=EK/cos(45°-θ),
[0068]
[0069] BK=BC×cos45°,
[0070] Available EG=L 1.
[0071] So CD and FG are parallel and the distance from CD to AB is equal to the distance from FG to AB, so the straight line CD and the straight line FG coincide.
[0072] The optical path difference of the displacement platform 4 after rotating is: Y 2 =EF+FC-EB-BC. From the geometric knowledge, △EOB≈△COF (that is, the two shaded triangles in the figure are similar), and the similarity ratio is
[0073]
[0074] ∠GEF=2×θ;
[0075] From the above conditions, the following equation can be obtained:
[0076]
[0077] In ΔFJK, ∠BEK=45°-θ, ∠EKB=θ, known from the law of sines:
[0078]
[0079] Equations (1) and (2) are jointly solved to obtain the rotation angle θ of the micro-nano control platform.
[0080] Preferably, the measurement method further includes the steps:
[0081] S5: Calculate the translational movement distance a of the displacement platform along the second axis through the following formula 1 :
[0082] X 11 =X 1 +X 2 ,
[0083] X 1 = 2a 1 ,
[0084] Where X 1 Is the optical path difference received by the third laser interferometer 3 due to the translational movement of the displacement platform along the second axis; X 2 Is the optical path difference received by the third laser interferometer 3 due to the rotation of the displacement platform around the center point of the platform, X 2 =Y 2.
[0085] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention within.
