Polar axis type rotary table system carrying optical mirror surface and method

Abstract

The invention discloses a polar axis type turntable system carrying an optical mirror surface and a method and belongs to the technical field of optical equipment. In the prior art, a laboratory light path is controlled by manual adjustment, human errors are easily introduced, and the stability is poor. In the polar axis type rotary table system carrying the optical mirror surface, a two-dimensional reflector assembly is fixed on the upper side of a connecting plate, an area light source generator is located on the upper portion of a laboratory, a light source receiver is arranged at a certain height of a test bed on the right side of the two-dimensional reflector assembly, and a ball screw driving device and a guide rail are located at the bottom of the connecting plate and can move in the laboratory in a one-dimensional mode. The two-dimensional reflecting mirror assembly forms a precise two-dimensional rotating platform, and a reflecting light path is automatically tracked according to a control method of the two-dimensional reflecting mirror assembly. The device has universality in application scenes, and due to the unique closed-loop feedback control mechanism and the method of combining the area light source generator with the lead screw sliding rail, a light path has higher stability and accuracy.

Description

Technical Field

[0001] The invention discloses a polar axis turntable system and method equipped with an optical mirror, and belongs to the technical field of optical equipment. Background Art

[0002] In the fields of scientific research and industrial testing, especially in application scenarios such as optical experiments, material analysis, and precision instrument calibration, precise control of the optical path is crucial. Traditional optical path control methods, such as manual adjustment of complex mechanical structures, not only limit the flexibility and accuracy of optical path adjustment, but are also inefficient and prone to human errors. Especially in optical experiments conducted in darkroom environments, there are extremely high requirements for the stability, directivity, and verticality of the light source to ensure the accuracy and repeatability of experimental data.

[0003] Therefore, an optical device that can automatically adjust the light path according to experimental requirements is a technical problem in this technical field.

[0004] Patent number CN118151364A provides a two-dimensional turntable design for large-aperture space telescopes, which is used for automatic capture, tracking, aiming and other tasks of space laser communications. It can be seen that its application scenario is not suitable for laboratories (dark rooms), and there are problems such as small degrees of freedom and small size of the mirror. It does not meet the experimental requirements of optical experiments, material analysis, precision instrument calibration and other experiments in laboratory (dark room) environments.

[0005] To this end, in order to overcome the limitations of existing technologies, achieve efficient and precise reflection and positioning of the optical path, ensure that the reflected light can accurately reach the light source receiver in the experimental area, and meet specific verticality requirements, there is an urgent need for optical equipment that can control the optical path stably, accurately, and with diverse paths. Summary of the invention

[0006] In order to solve the key problems of accuracy, stability, path diversity and efficient reflection positioning of light path control in a laboratory (darkroom) environment, the present invention proposes a "polar axis turntable system equipped with an optical mirror".

[0007] In the polar axis turntable system equipped with an optical mirror, the two-dimensional reflector assembly 2 is fixed on the upper side of the connecting plate 1, the surface light source generator 3 is located on the upper part of the laboratory, the light source receiver 4 is located at a certain height of the test bench on the right side of the two-dimensional reflector assembly 2, and the ball screw drive device 11 and the guide rail are located at the bottom of the connecting plate 1, so that the two-dimensional reflector assembly 2 can move in one dimension along the central axis of the laboratory, such as Figure 1 As shown;

[0008] like Figure 3 , Figure 4As shown, in the two-dimensional reflector assembly 2, the reflector 21 is connected to the open end of the U-shaped frame 22 through a bearing, and a pitch angle tracking motor 24 and an encoder are installed at the connection. The pitch angle tracking motor 24 drives the reflector 21 to perform pitch swing with the U-shaped end axis a of the U-shaped frame 22 as the axis. The extended end of the U-shaped frame 22 is connected to the frame 23 through a bearing, and an azimuth angle tracking motor 25 and an encoder are installed at the connection. The azimuth angle tracking motor 25 drives the U-shaped frame 22 to perform azimuth swing with the extended end axis b as the axis, and the reflector 21 and the U-shaped frame 22 swing synchronously;

[0009] like Figure 5 As shown, in the reflector 21, a support frame 211 with honeycomb topology weight reduction is used to support the reflector 21, and 6 support holes 2111 are provided inside the support frame 211, and Invar flexible joints 2112 are installed inside the support holes 2111. A support frame cover 212 is installed at one end of the support frame 211, and an optical mirror 215 is fixed to the support frame 211 at the other end by stacking a flexible gasket 213 and a rigid gasket 214, and the flexible gasket 213 is in contact with the optical mirror 215. A layer of Invar gasket 216 with hexagonal honeycomb weight reduction is added to the back of the optical mirror 215, and the Invar gasket 216 is rigidly connected to the Invar flexible joint 2112; the two-dimensional reflector assembly 2 can reflect the light generated by the surface light source generator 3 to the light source receiver 4 according to program control;

[0010] The light source receiver 4 includes a photosensitive element 41 and a feedback sensor; the input end of the light source receiver 4 is electrically connected to the photosensitive element 41, and the output end of the light source receiver 4 is electrically connected to the pitch angle tracking motor 24, the azimuth angle tracking motor 25, and the ball screw driving device 11 respectively; wherein the photosensitive surface of the photosensitive element 41 is perpendicular to the output optical axis, and the light source receiver 4 controls the pitch angle tracking motor 24, the azimuth angle tracking motor 25, and the ball screw driving device 11 according to the signal transmitted by the photosensitive element 41, as shown in FIG. Figure 2 As shown;

[0011] The control method of the polar axis turntable system equipped with an optical mirror is a combination of a program control mode and a feedback adjustment mode. First, a laboratory coordinate system is established with the initial position of the device as the origin. The light source generator 3 has a certain position relationship in the laboratory coordinate system. The two-dimensional reflector assembly 2 is slid to the calculated position through the ball screw drive device 11; the second step is to control the pitch angle tracking motor 24 and the azimuth angle tracking motor 25 through the tracking algorithm in the light source receiver 4 to adjust the pitch angle and azimuth angle of the two-dimensional reflector assembly 2, so that the mirror reflects the light source at a predetermined position; the third step is to enter the feedback closed-loop control mode for precise tracking, and the light is reflected to the photosensitive element 41 installed on the light source receiver 4. The photosensitive element 41 uses the optical principle of pinhole imaging to detect the current position, and controls the pitch angle tracking motor 24 and the azimuth angle tracking motor 25 to further improve the optical path, complete the closed-loop control, and realize the accuracy, stability and path diversity of the optical path control.

[0012] The technical effects of the present invention are as follows.

[0013] 1. The precise two-dimensional rotating platform cooperates with the lead screw to form a three-dimensional adjustable optical plane mirror structure, which can reflect the light of the surface light source emitter at a determined position in the laboratory, and the matching control tracking method and encoder make the directional tracking angle error less than 0.1°.

[0014] 2. The present invention adopts the method of adding Invar gasket support and Invar flexible joint support on the back of the mirror to enhance the overall rigidity of the mirror and ensure the surface accuracy of the optical mirror.

[0015] 3. The present invention adopts a polar axis structure, which can achieve smooth changes in two-axis angles when facing a fixed surface light source at the zenith or with a high pitch angle, and the tracking effect is better than that of a horizontal platform.

[0016] 4. The reflector of the present invention is made of low expansion rate high borosilicate material, and uses aluminum film + dielectric film as the main reflective film, and adds silicon dioxide film for protection to prevent the aluminum film from being oxidized for a long time and reducing the reflectivity. The average reflectivity after coating exceeds 92%, among which the average reflectivity in the 0.3-0.7 micron band is 88.69%, and the average reflectivity in the 0.7-2.5 micron band is 93.02%.

[0017] 5. The present invention can be used to conduct optical path adjustable experiments in conventional laboratories and has a certain degree of universality. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic front view of the polar axis turntable system equipped with an optical mirror in a laboratory room of the present invention.

[0019] Figure 2This is a schematic diagram of the working relationship of the various components of the polar axis turntable system equipped with an optical mirror of the present invention. This figure is also a schematic diagram of the method of the polar axis turntable system equipped with an optical mirror of the present invention, and this figure also serves as an abstract illustration.

[0020] Figure 3 It is a schematic front view of the tracking reflector assembly structure in the polar axis turntable system equipped with an optical mirror of the present invention.

[0021] Figure 4 It is a right side schematic diagram of the tracking reflector assembly structure in the polar axis turntable system equipped with an optical mirror of the present invention.

[0022] Figure 5 It is a schematic exploded perspective view of a tracking reflector in a polar axis turntable system equipped with an optical mirror according to the present invention. DETAILED DESCRIPTION

[0023] In the polar axis turntable system equipped with an optical mirror of the present invention, in the reflector 21, a support frame 211 is used to support the reflector 21, which needs to swing around the pitch axis. The support method is that the two ends are fixed and the middle is stressed. Under the premise of ensuring that the mirror surface does not deform, the mass is relatively large. Therefore, the support frame 211 is topologically lightened and structurally optimized. The size and wall thickness of the hexagonal lightweight hole are determined according to the results of direct optimization by ANSYS as a wall thickness of 6mm, and the diameter of the hexagonal inscribed circle is 50mm. The support cylinder structure is an inner circle and an outer square, and there is a circular thickening at the connection with the shaft to enhance rigidity. Six support holes 2111 are arranged inside the support frame 211, and an Invar flexible joint 2112 is installed inside the support hole 2111; a support frame cover 212 is installed at one end of the support frame 211, and an optical mirror 215 is fixed to the support frame 211 at the other end by stacking a flexible gasket 213 and a rigid gasket 214. The flexible gasket 213 is made of polytetrafluoroethylene material and has a certain impact resistance. The rigid gasket 214 is made of 304 stainless steel and can be connected to the flexible bottom film 213 by bolts. The flexible gasket 213 is in contact with the optical mirror 215. The optical mirror 215 is made of low expansion rate high borosilicate material. Aluminum film + dielectric film is selected as the main reflection film, and silicon dioxide film is added for protection to prevent the aluminum film from being oxidized for a long time and reducing the reflectivity. After coating, the average reflectivity exceeds 92%, wherein the average reflectivity is 88.69% in the 0.3-0.7 micron band and 93.02% in the 0.7-2.5 micron band. A layer of invar gasket 216 with hexagonal honeycomb weight reduction is added to the back of the optical mirror 215. The contact part with the mirror 215 needs to be precisely ground. Considering that the area of ​​the optical mirror 215 is relatively large, some contact points must be designed on the back of the mirror for the connection between the invar gasket and the optical mirror 215. The invar gasket 216 is rigidly connected to the invar flexible joint 2112, such as Figure 5 As shown;

[0024] The light source receiver 4 includes an embedded control system for receiving signals and issuing instructions, which communicates with the light source receiver 4 through a differential serial interface and is operated by the light source receiver 4; the light source receiver 4 also includes an indoor monitoring camera 43 to observe the system working conditions in the laboratory and feed the picture back to the light source receiver 4, and the light source receiver 4 is also connected to an audible and visual reminder 42 to give audible and visual warnings during movement to remind the operator to avoid scratches, such as Figure 2 shown.

[0025] The control method of the polar axis turntable system equipped with an optical mirror comprises the following steps: first, moving the two-dimensional reflector assembly 2 to a specified position through a ball screw drive device 11; second, coarse tracking using a program-controlled tracking mode, controlling the pitch angle tracking motor 24 and the azimuth angle tracking motor 25 to adjust the pitch angle and azimuth angle of the two-dimensional reflector assembly 2 through an embedded control system included in a light source receiver 4, so that the mirror reflects the light source at a predetermined position; third, fine tracking using an optical path position feedback closed-loop control mode, reflecting light to a photosensitive element 41 installed on the light source receiver 4, the photosensitive element 41 adopts the optical principle of pinhole imaging, the center of the aperture of the photosensitive element 41 is a small hole, facing the center of the detector surface to ensure the symmetry of the field of view, transmitting four-quadrant signals according to position feedback, controlling the pitch angle tracking motor 24 and the azimuth angle tracking motor 25 to further improve the optical path, complete closed-loop control, and achieve accuracy, stability, and path diversity of optical path control.

[0026] In summary, the present invention has a wide range of application scenarios, and its unique closed-loop feedback control mechanism and the method of combining a surface light source generator with a lead screw slide rail make the optical path more stable and accurate.

Claims

1. A polar axis turntable system equipped with an optical mirror, characterized in that: The two-dimensional reflector assembly (2) is fixed on the upper side of the connecting plate (1), the surface light source generator (3) is located at the upper part of the laboratory, the light source receiver (4) is arranged at a certain height of the test bench on the right side of the two-dimensional reflector assembly (2), and the ball screw drive device (11) and the guide rail are located at the bottom of the connecting plate (1), so that the two-dimensional reflector assembly (2) can move in one dimension along the central axis of the laboratory; In a two-dimensional reflector assembly (2), a reflector (21) is connected to an open end of a U-shaped frame (22) via a bearing, a pitch angle tracking motor (24) and an encoder are installed at the connection, the pitch angle tracking motor (24) drives the reflector (21) to perform pitch swing with the axis a of the U-shaped end of the U-shaped frame (22) as the axis, the extended end of the U-shaped frame (22) is connected to a frame (23) via a bearing, an azimuth angle tracking motor (25) and an encoder are installed at the connection, the azimuth angle tracking motor (25) drives the U-shaped frame (22) to perform azimuth swing with the axis b of the extended end as the axis, and the reflector (21) and the U-shaped frame (22) swing synchronously; In the reflector (21), a honeycomb topology weight-reducing support frame (211) is used to support the reflector (21), six support holes (2111) are provided inside the support frame (211), and an Invar flexible joint (2112) is installed inside the support hole (2111); a support frame cover (212) is installed at one end of the support frame (211), and an optical mirror surface (215) is fixed to the support frame (211) at the other end by stacking a flexible gasket (213) and a rigid gasket (214), the flexible gasket (213) is in contact with the optical mirror surface (215), and a layer of Invar gasket (216) with hexagonal honeycomb weight-reduction is added to the back of the optical mirror surface (215), and the Invar gasket (216) is rigidly connected to the Invar flexible joint (2112); the two-dimensional reflector assembly (2) can reflect light generated by a surface light source generator (3) to a light source receiver (4) according to program control; The light source receiver (4) comprises a photosensitive element (41) and a feedback sensor; the input end of the light source receiver (4) is electrically connected to the photosensitive element (41), and the output end of the light source receiver (4) is electrically connected to a pitch angle tracking motor (24), an azimuth angle tracking motor (24), and a ball screw driving device (11) respectively; wherein the photosensitive surface of the photosensitive element (41) is perpendicular to the output optical axis, and the light source receiver (4) controls the pitch angle tracking motor (24), the azimuth angle tracking motor (25), and the ball screw driving device (11) according to a signal transmitted by the photosensitive element (41).

2. The polar axis turntable system equipped with an optical mirror according to claim 1, characterized in that: The support frame (211) has a wall thickness of 6 mm, a hexagonal inscribed circle diameter of 50 mm, a support tube structure with an inner circle and an outer square, and a circular thickening at the connection with the shaft to enhance rigidity; the flexible gasket (213) is made of polytetrafluoroethylene material, which has a certain buffering effect on impact and will not damage the mirror surface; the rigid gasket (214) is made of 304 stainless steel.

3. The polar axis turntable system equipped with an optical mirror according to claim 1, characterized in that: The optical mirror (215) is made of a low expansion rate high borosilicate material, and uses an aluminum film + a dielectric film as the main reflection film, and a silicon dioxide film is added for protection to prevent the aluminum film from being oxidized over a long period of time and reducing the reflectivity.

4. The polar axis turntable system equipped with an optical mirror according to claim 1, characterized in that: The light source receiver (4) comprises an embedded control system for receiving signals and issuing instructions, which is electrically connected to the light source receiver (4) via a differential serial interface and is operated by the light source receiver (4); the light source receiver (4) is also connected to an indoor monitoring camera (43) for observing the working conditions of the system in the laboratory and feeding back the images to the light source receiver (4); the light source receiver (4) is also connected to an audible and visual reminder (42) for giving audible and visual warnings during movement to remind operators to avoid scratches.

5. A control method for a polar axis turntable system equipped with an optical mirror, characterized in that: The first step is to move the two-dimensional reflector assembly (2) to a specified position through a ball screw drive device (11); the second step is to use a program-controlled tracking mode for coarse tracking, and to control a pitch angle tracking motor (24) and an azimuth angle tracking motor (25) to adjust the pitch angle and azimuth angle of the two-dimensional reflector assembly (2) through an embedded control system included in a light source receiver (4), so that the mirror surface reflects the light source at a predetermined position; The third step is to use the optical path position feedback closed-loop control mode for precise tracking, and reflect the light to the photosensitive element (41) installed on the light source receiver (4). The photosensitive element (41) adopts the optical principle of pinhole imaging. The center of the aperture of the photosensitive element (41) is a small hole, which is directly opposite to the center of the detector surface to ensure the symmetry of the field of view. According to the position feedback, the four-quadrant signal is transmitted to control the pitch angle tracking motor (24) and the azimuth angle tracking motor (25) to further improve the optical path, complete the closed-loop control, and realize the accuracy, stability and path diversity of the optical path control.

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