Miniaturized laser communication coarse pointing mechanism

Abstract

This invention discloses a miniaturized laser communication coarse pointing mechanism, belonging to the field of space laser communication technology. The invention includes an elevation axis system, a single-pendulum mirror assembly, an azimuth axis system, and a telescope assembly. The single-pendulum mirror assembly is mounted on a U-shaped frame of the elevation axis system, which is mounted on the main shaft of the azimuth axis system. A motor and reducer drive the single-pendulum mirror assembly to rotate. The azimuth axis system is mounted on an azimuth base, and a motor drives a backlash-free gear to rotate the axis system. The telescope assembly is installed inside the azimuth axis system. Signal light enters and exits the coarse pointing mechanism after being deflected by the single-pendulum mirror assembly and expanded and contracted by the telescope assembly. This invention provides a miniaturized laser communication coarse pointing mechanism with advantages such as small size, light weight, and simple assembly and adjustment. It effectively solves the problems of complex structure, large size and weight, and high transmission cost of traditional laser communication terminals, providing a solution for the miniaturization of laser communication terminals.

Description

Technical Field

[0001] This invention relates to the field of space laser communication technology, and in particular to a compact, small-sized, and lightweight laser communication coarse pointing mechanism, specifically a miniaturized laser communication coarse pointing mechanism. Background Technology

[0002] With the development of optical communication technology, laser communication technology has begun to be applied in the space field. Laser communication devices use lasers as information carriers to achieve high-speed and stable data transmission. In the future, as the technology matures, laser communication devices will play an important role in data transmission and communication between satellites and the ground, and between satellites.

[0003] Laser communication devices are the foundation for inter-satellite networking and constellation construction. With the application of on-orbit high-definition imaging and tracking systems, their demand will grow exponentially. Low-cost development and launch are inevitable requirements. Therefore, miniaturization and lightweight design are inevitable trends. Existing laser communication terminals have complex structures, are difficult to assemble and adjust, and are relatively heavy and bulky, making it difficult to meet the requirements of miniaturization and mass production. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a miniaturized laser communication coarse pointing mechanism to meet the miniaturization requirements of laser communication terminals.

[0005] The objective of this invention is achieved through the following technical solution: a miniaturized laser communication coarse pointing mechanism, comprising: an elevation axis system, a single pendulum mirror assembly, an azimuth axis system, and a telescope assembly;

[0006] The pitch axis system includes a U-shaped frame, with a fixed shaft and a movable shaft at each end, adopting a structure where one end is fixed and the other end is movable. The movable shaft is connected to the pitch motor through a reducer to drive the U-shaped frame to perform pitch movement. The cooperation with the reducer effectively reduces the impact of micro-jitter of the tilting mirror during optical communication, while making start-up, stopping, and locking more reliable and easier to pass ground-based vibration tests. A filter is provided at the bottom of the U-shaped frame.

[0007] The single pendulum mirror assembly is mounted on the U-shaped frame, and the U-shaped frame drives the single pendulum mirror assembly to perform pitch movement. The single pendulum mirror assembly is used to realize the deflection of signal light into and out of the laser communication machine.

[0008] The azimuth axis system includes an azimuth axis, an internal azimuth gear, an external azimuth gear, and an azimuth motor. The upper end of the azimuth axis is fixedly connected to the U-shaped frame, and the lower end is fixedly connected to the internal azimuth gear. The azimuth motor drives the internal azimuth gear to rotate through the external azimuth gear, thereby driving the azimuth axis to rotate, and driving the pendulum mirror assembly to rotate in azimuth through the U-shaped frame.

[0009] The telescope assembly is mounted on the base of the azimuth axis system, and the telescope assembly is used to expand and contract the signal light beam.

[0010] Furthermore, the fixed shaft and the movable shaft are respectively mounted on the U-shaped frame by a pair of angular contact ball bearings. The fixed shaft is fixed by an outer pressure ring, an inner pressure ring and a pitch encoder code disk holder, and an encoder reading head bracket is provided on the outer side. The pitch encoder code disk holder is provided with an encoder code disk, which is used in conjunction with the encoder reading head provided on the encoder reading head bracket. The outermost side of the fixed shaft is provided with a pitch housing to protect the encoder code disk and the encoder reading head.

[0011] Furthermore, the single pendulum mirror assembly includes a pendulum mirror, a pendulum mirror bushing, and a pendulum mirror back plate; the pendulum mirror is fixedly connected to the pendulum mirror back plate through the pendulum mirror bushing, and the pendulum mirror bushing has a flexible structure to prevent thermal stress caused by temperature changes from affecting the surface accuracy of the pendulum mirror; the pendulum mirror adopts an eccentric structure to reduce the height of the pitch axis system.

[0012] Furthermore, the azimuth axis system includes an azimuth bearing, an azimuth base, an azimuth encoder, a reference prism, and a reference prism mount; the azimuth axis is fixed to the azimuth base via the azimuth bearing; the azimuth encoder is mounted in a groove provided on the azimuth axis; and the reference prism is mounted to the azimuth base via the reference prism mount.

[0013] Furthermore, the telescope assembly includes a primary mirror, a secondary mirror, a secondary mirror bracket, an adjustment shim, a reflector, and a telescope base. The miniaturized configuration of the telescope assembly greatly reduces the volume and weight of the coarse pointing mechanism. The secondary mirror is mounted above the primary mirror via the secondary mirror bracket, and the focal length between the primary and secondary mirrors is adjusted via the adjustment shim. The reflector is mounted on the primary mirror, and the primary mirror, secondary mirror, and reflector are coaxially mounted on the telescope base, thereby refracting the signal light into and out of the telescope assembly.

[0014] Furthermore, the pitch motor is fixedly connected to the reducer via a motor mounting base, and the reducer is connected to the floating shaft via a flange. It can also fix the angular contact ball bearing to the floating pitch shaft. At the same time, the flange also controls the rotation angle of the pitch shaft system, playing the role of pitch rotation limit. The U-shaped frame is provided with limit posts to control the rotation range of the U-shaped frame.

[0015] Furthermore, the filter is fixed to the bottom of the U-shaped frame via a filter base, and the bottom of the U-shaped frame is also provided with an electrical wire cover plate.

[0016] Furthermore, the azimuth bearing is a four-point contact ball bearing. The inner ring of the four-point contact ball bearing is mounted on the azimuth shaft through the inner bearing pressure ring, and the outer ring is mounted on the azimuth base through the outer bearing pressure ring. This enables the azimuth shaft system to withstand radial and axial loads, effectively shortening the length of the azimuth shaft system. At the same time, the four-point contact ball bearing adopts a solid coating lubrication process to prevent the evaporation of grease lubricating gas from contaminating the mirror surface.

[0017] Furthermore, the external gear includes a driving gear, a torsion spring, and a driven gear. The driving gear is mounted on the main shaft of the orientation motor, and the driven gear is connected to the driving gear through the torsion spring. The tooth surfaces of the driving gear and the driven gear are offset by the preloaded torsion spring, so that the tooth surfaces of the driving gear and the driven gear respectively fit with the tooth surfaces of the internal gear, thereby eliminating gear transmission backlash.

[0018] Furthermore, the azimuth axis system also includes an azimuth cover plate, a cable management tray, a screed, and an adapter flange. The azimuth cover plate is fixed on the azimuth base to protect the azimuth encoder. The cable management tray is installed on the azimuth base to store the wires of the pitch axis system. The azimuth base is fixed to the adapter flange with screws, and the positions of the azimuth base and the adapter flange are adjusted by the screed.

[0019] Furthermore, the primary mirror adopts an integrated design of the mirror body and the mirror mount, and the mounting point is designed with flexible features to achieve stress-free installation, ensuring the surface accuracy of the primary mirror during installation and adjustment. At the same time, it can achieve adaptive compensation for thermal deformation when the temperature changes, solve the problem of concentrated stress, and improve the temperature adaptability of the system.

[0020] The beneficial effects of this invention are as follows: The miniaturized laser communication coarse pointing mechanism of this invention adopts an eccentric structure for the single pendulum mirror assembly, which effectively reduces the height of the pitch axis system. The innovative use of a four-point contact ball bearing in the azimuth axis system significantly reduces the height of the azimuth axis system. The telescope assembly is designed inside the azimuth axis system, which effectively saves internal redundant space. The structure is compact and reduces the difficulty of assembly and adjustment. The photoelectric encoder adopts a patch structure, which reduces the weight of auxiliary components. The design of torsion spring backlash-free gear transmission in the small-size gear transmission process makes the transmission more stable and reliable. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is the front view of the present invention;

[0023] Figure 2 This is a cross-sectional view of the pitch axis system of the present invention;

[0024] Figure 3 This is a cross-sectional view of the single pendulum mirror assembly of the present invention;

[0025] Figure 4 This is a left sectional view of the present invention;

[0026] Figure 5 This is a diagram of the backlash-free gear assembly of the present invention;

[0027] Figure 6 This is an axonometric view of the telescope assembly of the present invention.

[0028] Explanation of reference numerals in the attached figures:

[0029] 1-Pitch axis system; 2-Single pendulum mirror assembly; 3-Azimuth axis system; 4-Telescope assembly; 11-Fixed axis; 12-Roaming axis; 13-U-shaped bracket; 14-Angular contact ball bearing; 15-Outer pressure ring; 16-Inner pressure ring; 17-Pitch encoder code disk holder; 18-Encoder code disk; 19-Encoder read head bracket; 111-Pitch housing; 112-Pitch motor; 113-Reducer; 114-Motor mounting base; 115-Flange; 116-Limit post; 117-Wire cover plate; 118-Filter; 119-Filter base; 21-Pitch mirror; 22-Pitch mirror bushing; 23- Backplate of the azimuth mirror; 31-azimuth shaft; 32-azimuth bearing; 33-azimuth base; 34-inner bearing pressure ring; 35-outer bearing pressure ring; 36-inner azimuth gear; 37-outer azimuth gear; 38-azimuth motor; 39-azimuth encoder; 311-azimuth cover plate; 312-cable tray; 313-reference prism; 314-reference prism mount; 315-refinement shim; 316-adapter flange; 371-drive gear; 372-torsion spring; 373-driven gear; 41-primary mirror; 42-secondary mirror; 43-secondary mirror bracket; 44-adjustment shim; 45-reflector; 46-telescope base. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] It should be noted that, unless otherwise specified, the features in the following embodiments and implementation methods can be combined with each other.

[0032] like Figure 1As shown, this embodiment of the invention provides a miniaturized laser communication coarse pointing mechanism to achieve miniaturization of the laser communication coarse pointing mechanism, mainly including a pitch axis system 1, a single pendulum mirror assembly 2, an azimuth axis system 3, and a telescope assembly 4.

[0033] The single-pendulum mirror assembly 2 is mounted on the pitch axis system 1 and is driven to swing up and down by the power device of the pitch axis system 1. The pitch axis system 1 is vertically mounted above the azimuth axis system 3 and is driven to rotate by the gear transmission mechanism of the azimuth axis system 3, which in turn drives the pitch axis system 1 to rotate left and right. The telescope assembly 4 is fixedly mounted inside the azimuth axis system 3. The 45° reflector of the telescope assembly 4 is directly opposite the light-transmitting hole on the adapter flange of the azimuth axis system 3. The single-pendulum mirror assembly 2 is driven to move up and down and left and right in space by the power devices of the pitch axis system 1 and the azimuth axis system 3 to achieve the capture and tracking of the light path.

[0034] As a preferred embodiment, such as Figure 2 As shown, the pitch axis system 1 adopts a three-axis connection structure consisting of a fixed axis 11, a mirror assembly 2, and a sliding axis 12. The pitch axis system 1 includes a U-shaped frame 13. The fixed axis 11 and the sliding axis 12 are respectively located at both ends of the U-shaped frame 13. The sliding axis 12 is connected to the pitch motor 112 through a reducer 113 to drive the U-shaped frame 13 to perform pitch movement.

[0035] Preferably, both the fixed shaft 11 and the movable shaft 12 are mounted back-to-back on the U-shaped frame 13 by angular contact ball bearings 14. The fixed shaft 11 is fixed by an outer pressure ring 15 and an inner pressure ring 16 and screwed to a pitch encoder code disk holder 17. The pitch encoder code disk holder 17 is designed with a mounting groove, and the encoder code disk 18 is centered and bonded in the mounting groove for use with the encoder reading head. It can accurately detect the rotation angle of the single pendulum mirror assembly 2. The encoder reading head is bonded to the encoder reading head bracket 19. The reading head bracket 19 is designed with a ground boss, which can adjust the distance between the reading head and the encoder code disk 18, so that the encoder signal value is in the optimal range. To avoid interference from external light, the encoder is completely enclosed in the pitch housing 111.

[0036] The power unit is installed at the movable end of the U-shaped frame 13. The pitch motor 112 is fixedly connected to the reducer 113 through the motor mounting base 114. The two are connected to the movable shaft 12 through the flange 115. The flange 115 has an extension column, which can control the rotation range of the pitch axis system by cooperating with the limiting column 116 on the U-shaped frame 13. The filter 118 is installed below the mirror assembly 2 and is bonded to the filter base 119. The filter 118 is installed at a 2° angle to the horizontal plane.

[0037] The bottom end of the U-shaped frame 13 is also provided with a wire cover plate 117, which is used to coil the wires of the pitch axis system 1 inside the wire management tray 312 to prevent the wires from jumping out of the wire management tray 312 during rotation.

[0038] As a preferred embodiment, such as Figure 3 As shown, the single pendulum mirror assembly 2 includes a pendulum mirror 21, a pendulum mirror bushing 22, and a pendulum mirror back plate 23. The single pendulum mirror assembly 2 is eccentrically placed on the U-shaped frame 13 and is fixed to the fixed shaft 11 and the floating shaft 12 by screws. To ensure the coaxiality of the three, the pendulum mirror back plate 23 is designed with positioning holes with flexible joints. Since the coarse pointing mechanism works outside the cabin, in order to reduce the influence of temperature changes on the surface accuracy of the mirror, the pendulum mirror 21 adopts a design with a pendulum mirror bushing 22 with flexible joints on the back. The linear expansion coefficient of the material of the pendulum mirror bushing 22 is similar to that of the pendulum mirror 21. It is fixed to the pendulum mirror 21 by adhesive. The pendulum mirror bushing 22 is fixed to the pendulum mirror back plate 23 by screws. Flexible joints are designed at all fixed points of the single pendulum mirror assembly 2 to reduce the influence of stress on the surface of the pendulum mirror 21.

[0039] As a preferred embodiment, such as Figure 4 As shown, the azimuth axis system 3 is located below the pitch axis system 1 and is vertically installed to the pitch axis system 1 via an azimuth shaft 31. The azimuth shaft 31 is fixed to the azimuth base 33 via an azimuth bearing 32. An internal azimuth gear 36 is installed at the lower part of the azimuth shaft 31 and is connected to an azimuth motor 38 via an external azimuth gear 37. The azimuth motor 38 drives the azimuth axis system 3 to rotate. An azimuth encoder 39 mounting slot is designed on the azimuth shaft 31 to ensure that the azimuth encoder 39 is aligned and bonded to the azimuth shaft 31. A reference prism 313 is installed on the azimuth base 33 via a reference prism seat 314 and is used to locate the position of the coarse pointing mechanism. A cable management disc 312 is installed on the azimuth base 33 to wind the wires of the pitch axis system 1. At the same time, a stop is designed on the cable management disc 312 to limit the rotation range of the azimuth axis system 3.

[0040] Preferably, the azimuth bearing 32 is a four-point contact ball bearing. The inner ring of the four-point contact ball bearing is mounted on the azimuth shaft 31 through the inner bearing pressure ring 34, and the outer ring is mounted on the azimuth base 33 through the outer bearing pressure ring 35, so that the azimuth shaft system 3 can withstand radial loads and axial loads.

[0041] Preferred, such as Figure 5As shown, the azimuth external gear 37 includes a driving gear 371, a torsion spring 372, and a driven gear 373. The driving gear 371 is mounted on the main shaft of the azimuth motor 38, and the driven gear 373 is connected to the driving gear 371 through the torsion spring 372. Since the pitch circle diameter of the azimuth external gear 37 is small, a traditional tension spring structure cannot be used. Therefore, the tooth surfaces of the driving gear 371 and the driven gear 373 are misaligned by pre-compressing the torsion spring 372, so that the tooth surfaces of the driving gear 371 and the driven gear 373 respectively fit into the tooth surface of the internal gear 36, eliminating gear transmission backlash and ensuring smooth transmission.

[0042] Preferably, the azimuth axis system 3 further includes an azimuth cover plate 311, a screed 315, and a transition flange 316. The azimuth cover plate 311 is fixed to the azimuth base 33 by screws to protect the azimuth encoder 39. The screed 315 is used to adjust the position of the azimuth base 33 and the transition flange 316. The transition flange 316 serves as the main load-bearing structure of the entire device and plays a supporting role.

[0043] As a preferred embodiment, such as Figure 6 As shown, the telescope assembly 4 is fixed inside the azimuth axis system 3 by screws, including a primary mirror 41, a secondary mirror 42, a secondary mirror bracket 43, an adjustment shim 44, a reflector 45, and a telescope base 46. The secondary mirror 42 is fixed to the primary mirror 41 by the secondary mirror bracket 43. The focal length between the primary mirror 41 and the secondary mirror 42 can be finely adjusted by the adjustment shim 44. The primary mirror 41, together with the secondary mirror 42 and the reflector 45, is coaxially fixed to the telescope base 46. In order to reduce the impact of installation stress on the surface accuracy of the mirror, flexible features are designed around the screw fixing points to achieve stress-free installation. The reflector 45 refracts light into and out of the telescope assembly 4 through the light-passing hole on the adapter flange 316. At the same time, in the coarse pointing mechanism, the inner wall surface of the component through which the light passes is blackened to reduce the impact of stray light on the signal.

[0044] The various embodiments in this invention are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0045] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A miniaturized laser communication coarse pointing mechanism, characterized in that, include: Pitch axis (1), pendulum mirror assembly (2), azimuth axis (3) and telescope assembly (4); The pitch axis system (1) includes a U-shaped frame (13), with a fixed shaft (11) and a movable shaft (12) at both ends of the U-shaped frame (13). The movable shaft (12) is connected to the pitch motor (112) through a reducer (113) to drive the U-shaped frame (13) to perform pitch movement. A filter (118) is provided at the bottom of the U-shaped frame (13). The fixed shaft (11) and the movable shaft (12) are respectively mounted on the U-shaped frame (13) by a pair of angular contact ball bearings (14). The fixed shaft (11) is fixed by an outer pressure ring (15), an inner pressure ring (16) and a pitch encoder code disk holder (17), and an encoder reading head bracket (19) is provided on the outside. An encoder code disk (18) is provided on the pitch encoder code disk holder (17) and is used in conjunction with the encoder reading head provided on the encoder reading head bracket (19). The outermost part of the fixed shaft (11) is provided with a pitch housing (111) to protect the encoder code disk (18) and the encoder reading head. The single pendulum mirror assembly (2) is mounted on the U-shaped frame (13). The U-shaped frame (13) drives the single pendulum mirror assembly (2) to perform pitch motion. The single pendulum mirror assembly (2) is used to realize the folding and turning of signal light in and out. The single pendulum mirror assembly (2) includes a pendulum mirror (21), a pendulum mirror bushing (22), and a pendulum mirror back plate (23); the pendulum mirror (21) is fixedly connected to the pendulum mirror back plate (23) through the pendulum mirror bushing (22), the pendulum mirror bushing (22) has a flexible joint structure, and the pendulum mirror (21) adopts an eccentric structure; The azimuth axis system (3) includes an azimuth axis (31), an internal azimuth gear (36), an external azimuth gear (37), and an azimuth motor (38). The upper end of the azimuth axis (31) is fixedly connected to the U-shaped frame (13), and the lower end is fixedly connected to the internal azimuth gear (36). The azimuth motor (38) drives the internal azimuth gear (36) to rotate through the external azimuth gear (37), thereby driving the azimuth axis (31) to rotate, and driving the pendulum mirror assembly (2) to rotate in azimuth through the U-shaped frame (13). The telescope assembly (4) is installed inside the azimuth axis system (3), and the telescope assembly (4) is used to expand and shrink the signal light beam.

2. The miniaturized laser communication coarse pointing mechanism according to claim 1, characterized in that, The azimuth axis system (3) includes an azimuth bearing (32), an azimuth base (33), an azimuth encoder (39), a reference prism (313), and a reference prism seat (314); the azimuth axis (31) is fixed to the azimuth base (33) by the azimuth bearing (32); the azimuth encoder (39) is installed in a groove provided on the azimuth axis (31); the reference prism (313) is installed on the azimuth base (33) by the reference prism seat (314).

3. The miniaturized laser communication coarse pointing mechanism according to any one of claims 1-2, characterized in that, The telescope assembly (4) includes a primary mirror (41), a secondary mirror (42), a secondary mirror bracket (43), an adjustment shim (44), a reflector (45), and a telescope base (46). The secondary mirror (42) is mounted above the primary mirror (41) via the secondary mirror bracket (43), and the focal length between the primary mirror (41) and the secondary mirror (42) is adjusted via the adjustment shim (44). The reflector (45) is mounted on the primary mirror (41), and the primary mirror (41), the secondary mirror (42), and the reflector (45) are coaxially mounted on the telescope base (46).

4. The miniaturized laser communication coarse pointing mechanism according to claim 3, characterized in that, The pitch motor (112) is fixedly connected to the reducer (113) via the motor mounting base (114), and the reducer (113) is connected to the floating shaft (12) via the flange (115); the U-shaped frame (13) is provided with a limit post (116) to control the rotation range of the U-shaped frame (13).

5. The miniaturized laser communication coarse pointing mechanism according to claim 4, characterized in that, The filter (118) is fixed to the bottom of the U-shaped frame (13) by the filter base (119), and the bottom of the U-shaped frame (13) is also provided with an electrical wire cover plate (117).

6. The miniaturized laser communication coarse pointing mechanism according to claim 5, characterized in that, The azimuth bearing (32) is a four-point contact ball bearing. The inner ring of the four-point contact ball bearing is installed on the azimuth shaft (31) through the bearing inner pressure ring (34), and the outer ring is installed on the azimuth base (33) through the bearing outer pressure ring (35), so that the azimuth shaft system (3) can withstand radial load and axial load.

7. The miniaturized laser communication coarse pointing mechanism according to claim 6, characterized in that, The external azimuth gear (37) includes a driving gear (371), a torsion spring (372), and a driven gear (373). The driving gear (371) is mounted on the main shaft of the azimuth motor (38). The driven gear (373) is connected to the driving gear (371) through the torsion spring (372). The tooth surfaces of the driving gear (371) and the driven gear (373) are offset by the preloaded torsion spring (372), so that the tooth surfaces of the driving gear (371) and the driven gear (373) respectively fit with the tooth surfaces of the internal gear (36), thereby eliminating gear transmission backlash.

8. The miniaturized laser communication coarse pointing mechanism according to claim 7, characterized in that, The azimuth axis system (3) also includes an azimuth cover plate (311), a cable tray (312), a screed shim (315), and a transition flange (316); the azimuth cover plate (311) is fixed on the azimuth base (33) and is used to protect the azimuth encoder (39); the cable tray (312) is installed on the azimuth base (33) and is used to store the wires of the pitch axis system (1); the azimuth base (33) is fixed on the transition flange (316), and the positions of the two are adjusted by the screed shim (315).

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