Large secondary mirror deployable device of space optical remote sensing camera

Abstract

The invention discloses a large-scale secondary mirror deployable device for a space optical remote sensing camera. The large-scale secondary mirror deployable device comprises a plurality of turnover mechanisms and a plurality of unfolding mechanisms, wherein the turnover mechanisms are sequentially stacked and placed, and every two adjacent turnover mechanisms are connected through the corresponding unfolding mechanism; the turnover mechanism comprises an upper turnover plate and a lower turnover plate; the lower end face of the unfolding mechanism is connected with the upper turnover plate of the lower turnover mechanism, and the upper end face of the unfolding mechanism is connected with the lower turnover plate of the upper turnover mechanism. When the turnover mechanism is unfolded, the upper turnover plate and the lower turnover plate are vertically arranged; during folding, the upper turnover plate and the lower turnover plate are arranged in parallel; the unfolding direction of the unfolding mechanism can rotate by 90 degrees. According to the invention, large aperture, long focal length, light weight and two-dimensional plane expansion of the space optical remote sensing camera can be realized so as to meet the spatial resolution requirements of remote sensing satellites in the field of space remote sensing.

Description

Technical Field

[0001] The invention relates to a large secondary mirror deployable device for a space optical remote sensing camera, belonging to the technical field of deep space exploration. Background Art

[0002] With the rapid development of aerospace technology, space optical remote sensing cameras have been successfully applied to many fields such as deep space exploration, earth observation, space science research, resource monitoring, etc., and their development direction is mainly high resolution, lightweight, high stability, etc. With the improvement of the resolution requirements for space optical remote sensors, long focal length, large aperture, and space direction change are the inevitable development directions, which are obviously difficult to achieve with integral primary and secondary mirrors.

[0003] This requires that when the large secondary mirror deployable device of the space optical remote sensing camera is launched, the secondary mirror and the supporting mechanism are folded and retracted, and then driven to deploy in sequence after entering orbit. The deployable mechanism is one of the important technical means. It can achieve high precision and high compression ratio, and increase the possibility of long focal length and large aperture for the in-orbit deployment of the space optical remote sensing camera. Considering the rocket carrying capacity, the deployable mechanism must also be lightweight.

[0004] In addition, in special work, the secondary mirror deployable mechanism may also be required to have a steering function. Conventional space optical remote sensing camera deployment mechanisms can only be deployed in one dimension, which cannot meet the multi-dimensional detection tasks of optical remote sensing cameras in deep space exploration. Summary of the invention

[0005] The technical problem solved by the present invention is: to overcome the deficiencies of the prior art, to provide a large secondary mirror deployable device for a space optical remote sensing camera, and to solve the problem that the space optical mechanism has a large size when working in orbit and a small volume when folded for launch.

[0006] The technical solution of the present invention is:

[0007] The invention discloses a deployable device for a large secondary mirror of a space optical remote sensing camera, comprising: a plurality of flipping mechanisms and a plurality of deploying mechanisms; wherein the plurality of flipping mechanisms are stacked and placed in sequence, and two adjacent flipping mechanisms are connected via the deploying mechanism; the flipping mechanism comprises a motor assembly, a transmission shaft, a crank, a connecting rod, an upper flipping plate and a lower flipping plate; the lower end surface of the deploying mechanism is connected to the upper flipping plate of the flipping mechanism below, and the upper end surface is connected to the lower flipping plate of the flipping mechanism above; when the flipping mechanism is deployed, the upper flipping plate and the lower flipping plate are arranged vertically; when the flipping mechanism is folded, the upper flipping plate and the lower flipping plate are arranged in parallel; the motor assembly provides a torque for the transmission shaft, drives the transmission shaft to move, and drives the upper flipping plate to flip by driving the crank and the connecting rod; when it is detected that the upper flipping plate has rotated into place, the motor assembly stops working.

[0008] Furthermore, in the above-mentioned mechanism, the unfolding mechanism includes an extension mechanism and a speed control motor assembly; wherein, the extension mechanism is composed of a plurality of unfolding units connected in series; the unfolding unit is a triangular prism structure; the speed control motor assembly includes a speed control motor and a speed control rope; one end of the speed control rope is connected to the speed control motor and installed at one end of the extension mechanism; the other end of the speed control rope is connected to the other end of the extension mechanism; the speed control motor controls the release length of the speed control rope to pull the extension mechanism to the unfolding height.

[0009] Furthermore, in the above-mentioned mechanism, the unfolding unit includes a connecting frame assembly, a folding rod assembly, a scroll spring assembly and a tension cable assembly; wherein the scroll spring assembly is installed in the middle of the folding rod assembly to provide a driving torque for the folding rod assembly; the two connecting frame assemblies are respectively the upper and lower surfaces of the triangular prism structure; the upper and lower surfaces of the triangular prism structure are connected by three folding rod assemblies to provide support; the two ends of the tension cable assembly are respectively connected to the diagonal corners of the quadrilateral on the side of the triangular prism, and are arranged crosswise.

[0010] Furthermore, in the above mechanism, the connecting frame assembly includes a root hinge seat and a first carbon fiber rod; wherein, there are three root hinge seats and three first carbon fiber rods, the first carbon fiber rods form a triangle, and both ends of each first carbon fiber rod are respectively fixed to a root hinge seat.

[0011] Furthermore, in the above-mentioned mechanism, the folding rod assembly includes a root hinge and two second carbon fiber tubes; wherein, the root hinge is bonded and fixedly connected to the ends of the two second carbon fiber tubes, and the two second carbon fiber tubes are in a parallel state when in the folded state; the root hinge is respectively connected to the root hinge seats in the upper and lower connecting frame assemblies through rotation.

[0012] Furthermore, in the above-mentioned mechanism, the scroll spring assembly includes an active flap hinge, a driven flap hinge, a hinge rotating shaft, a deep groove ball bearing, a scroll spring outer end fixed shaft, a scroll spring and a bearing cover; wherein, the hinge rotating shaft is connected to the active flap hinge through a key, and the two ends of the hinge rotating shaft are respectively connected to the inner ends of the two scroll springs; rotating holes are provided in both the active flap hinge and the driven flap hinge; after the hinge rotating shaft passes through the rotating holes of the active flap hinge and the driven flap hinge, two deep groove ball bearings are passed through the inside at the same time; the right side is pressed axially for positioning by the bearing cover, and the bearing cover is connected to the outer end of the driven flap hinge; the outer end of the scroll spring is fixed on the fixed shaft at the outer end of the scroll spring; the fixed shaft at the outer end of the scroll spring is connected to the driven flap hinge, and axial positioning is achieved by a set screw.

[0013] Furthermore, in the above-mentioned mechanism, the tension cable assembly includes a tension cable, a tension cable hinge, a rotating shaft and a tension cable joint; wherein, the two ends of the tension cable joint are respectively a thick rod and a thin rod; a through hole is set at one end of the thin rod; the thick rod is inserted into a groove set in the middle part of the tension cable hinge; the tension cable passes through the through hole of the tension cable joint, and the thin rod of the tension cable joint is pressed and deformed by pressure to clamp the tension cable; the thin end of the rotating shaft is threaded, and after passing through the rotating hole set in the tension cable hinge, it is screwed into the threaded hole set on the connecting frame assembly for fixation.

[0014] Furthermore, in the above-mentioned mechanism, the speed control motor assembly includes a speed control rope steering mechanism, a drum, a spline, a speed control rope, a motor and a mounting seat; wherein, the speed control rope steering mechanism is fixedly connected to the mounting seat and a pulley is arranged; the speed control rope is wound around the drum after passing around the pulley and changing direction; the motor is connected to the mounting seat; a spline hole is arranged on the inner side of one end of the drum, and a thread is arranged on the other end; one end of the spline is connected to the motor, and the other end is inserted into the spline hole of the drum; the threaded end of the drum cooperates with the threaded hole arranged on the mounting seat; when the motor drives the drum to rotate, the drum moves left and right along the mounting seat; the position of the speed control rope remains unchanged after passing through the speed control rope steering mechanism, and the movement of the drum causes the speed control rope to be wound around the drum in sequence to prevent the speed control rope from being entangled and knotted.

[0015] The beneficial effects of the present invention and the prior art are:

[0016] (1) The present invention can complete the long focal length expansion of the secondary mirror of a space optical remote sensing camera by relying only on a scroll spring assembly and a small number of micro motors without the need for large-scale control equipment.

[0017] (2) The overall mass of the present invention is greatly reduced compared to the secondary mirror deployable mechanism of a traditional large-scale space optical remote sensing camera.

[0018] (3) Compared with the one-dimensional deployable mechanism of the secondary mirror of the traditional large-scale space optical remote sensing camera, the present invention is a two-dimensional planar deployable mechanism, which greatly increases the environmental adaptability and utilization rate of the deployable mechanism of the secondary mirror of the space optical remote sensing camera.

[0019] (4) The present invention designs a multi-stage deployment mechanism and adopts an articulated deployment mechanism with a small folded volume and reliable deployment, thereby realizing the long-focal-length deployment of the optical mechanism and solving the problem that the space optical mechanism has a large size when working in orbit and a small folded launch volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a structural diagram of the folded state of the large secondary mirror deployable device of the space optical remote sensing camera of the present invention;

[0021] Figure 2 This is a structural diagram of the unfolded state of the large secondary mirror unfoldable device of the space optical remote sensing camera of the present invention;

[0022] Figure 3 It is a structural diagram of the first-level turning mechanism of the present invention;

[0023] Figure 4 It is a structural diagram of the connecting frame assembly of the extension mechanism of the present invention;

[0024] Figure 5 This is a structural diagram of the folding rod assembly of the present invention;

[0025] Figure 6 It is a structural diagram of the scroll spring assembly of the present invention;

[0026] Figure 7 is a cross-sectional view of a scroll spring assembly of the present invention;

[0027] Figure 8 This is a structural diagram of the tension cable assembly of the present invention;

[0028] Fig. 9 Tension cable connection structure diagram of the present invention

[0029] Fig.10 This is a structural diagram of the speed control motor assembly of the present invention. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0031] like Figure 1 As shown, the present invention discloses a deployable device for a large secondary mirror of a space optical remote sensing camera, comprising: a plurality of flipping mechanisms and a plurality of deploying mechanisms; wherein the plurality of flipping mechanisms are stacked in sequence, and two adjacent flipping mechanisms are connected via the deploying mechanism; the flipping mechanism comprises an upper flipping plate 6 and a lower flipping plate 1; the lower end surface of the deploying mechanism is connected to the upper flipping plate 6 of the flipping mechanism below, and the upper end surface is connected to the lower flipping plate 1 of the flipping mechanism above; when the flipping mechanism is deployed, the upper flipping plate 6 and the lower flipping plate 1 are arranged vertically; when folded, the upper flipping plate 6 and the lower flipping plate 1 are arranged in parallel.

[0032] Preferably, the flipping mechanism also includes a motor assembly 2, a transmission shaft 3, a crank 4 and a connecting rod 5; wherein the motor assembly 2 provides torque for the transmission shaft 3, drives the transmission shaft 3 to move, and drives the upper flip plate 6 to flip by driving the crank 4 and the connecting rod 5; when it is detected that the upper flip plate 6 has rotated into place, the motor assembly 2 stops working.

[0033] Preferably, the unfolding mechanism comprises an extension mechanism and a speed control motor assembly 11; wherein the extension mechanism is composed of a plurality of unfolding units connected in series; the unfolding unit is a triangular prism structure; the speed control motor assembly 11 comprises a speed control motor and a speed control rope; one end of the speed control rope is connected to the speed control motor and installed at one end of the extension mechanism; the other end of the speed control rope is connected to the other end of the extension mechanism; the speed control motor controls the release length of the speed control rope to pull the extension mechanism to the unfolding height.

[0034] Preferably, the unfolding unit includes a connecting frame assembly 7, a folding rod assembly 8, a scroll spring assembly 9 and a tension cable assembly 10; wherein the scroll spring assembly 9 is installed in the middle of the folding rod assembly 8 to provide a driving torque for the folding rod assembly 8; the two connecting frame assemblies 7 are respectively the upper and lower surfaces of the triangular prism structure; the upper and lower surfaces of the triangular prism structure are connected by three folding rod assemblies 8 to provide support; the two ends of the tension cable assembly 10 are respectively connected to the diagonal corners of the quadrilateral on the side of the triangular prism, and are arranged crosswise.

[0035] Preferably, the connecting frame assembly 7 includes a root hinge seat 12 and a first carbon fiber rod 13; wherein, there are three root hinge seats 12 and three first carbon fiber rods 13, the first carbon fiber rods 13 form a triangle, and both ends of each first carbon fiber rod 13 are fixedly connected to a root hinge seat 12 respectively.

[0036] Preferably, the folding rod assembly 8 includes a root hinge 14 and two second carbon fiber tubes 15; wherein the root hinge 14 is bonded and fixedly connected to the ends of the two second carbon fiber tubes 15, and the two second carbon fiber tubes 15 are in a parallel state when folded; the root hinge 14 is respectively connected to the root hinge seats 12 in the upper and lower connecting frame assemblies 7 by rotation.

[0037] Preferably, the scroll spring assembly 9 includes an active flap hinge 17, a driven flap hinge 16, a hinge rotating shaft 18, a deep groove ball bearing 19, a scroll spring outer end fixed shaft 20, a scroll spring 21 and a bearing cover 22; wherein, the hinge rotating shaft 18 is connected to the active flap hinge 17 through a key, and the two ends of the hinge rotating shaft 18 are respectively connected to the inner ends of the two scroll springs 21; rotating holes are provided in both the active flap hinge 17 and the driven flap hinge 16; after the hinge rotating shaft 18 passes through the rotating holes of the active flap hinge 17 and the driven flap hinge 16, two deep groove ball bearings 19 are passed through the interior at the same time; the right side is pressed axially for positioning by the bearing cover 22, and the bearing cover 22 is connected to the outer end of the driven flap hinge 16; the outer end of the scroll spring 21 is fixed on the scroll spring outer end fixed shaft 20; the scroll spring outer end fixed shaft 20 is connected to the driven flap hinge 16, and axial positioning is achieved by a set screw.

[0038] Preferably, the tension cable assembly 10 includes a tension cable 23, a tension cable hinge 24, a rotating shaft 25 and a tension cable joint 32; wherein, the two ends of the tension cable joint 32 are respectively a thick rod and a thin rod; a through hole is set at one end of the thin rod; the thick rod is inserted into the groove set in the middle of the tension cable hinge 24; the tension cable 23 passes through the through hole of the tension cable joint 32, and the thin rod of the tension cable joint 32 is pressed and deformed by pressure to clamp the tension cable 23; the thin end of the rotating shaft 25 is threaded, and after passing through the rotating hole set in the tension cable hinge 24, it is screwed into the threaded hole set on the connecting frame assembly 7 for fixation.

[0039] Preferably, the speed control motor assembly 11 includes a speed control rope steering mechanism 26, a drum 27, a spline 28, a speed control rope 29, a motor 30 and a mounting seat 31; wherein the speed control rope steering mechanism 26 is fixedly connected to the mounting seat 31 and a pulley is provided; the speed control rope 29 passes around the pulley and changes direction before being wound around the drum 27; the motor 30 is connected to the mounting seat 31; a spline hole is provided on the inner side of one end of the drum 27, and a thread is provided at the other end; one end of the spline 28 is connected to the motor 30, and the other end is inserted into the spline hole of the drum 27; the threaded end of the drum 27 cooperates with the threaded hole provided on the mounting seat 31; when the motor 30 drives the drum 27 to rotate, the drum 27 moves left and right along the mounting seat 31; the position of the speed control rope 29 remains unchanged after passing through the speed control rope steering mechanism 26, and the movement of the drum 27 causes the speed control rope 29 to be wound around the drum 27 in sequence to prevent the speed control rope 29 from being entangled and knotted.

[0040] Example

[0041] The large secondary mirror deployable device for a space optical remote sensing camera described in this embodiment has a large deployed size through a combination of a multi-stage flipping mechanism and an deploying mechanism, thereby completing the function of deploying the secondary mirror of the space optical remote sensing camera to a long focal length.

[0042] The large secondary mirror deployable device of the space optical remote sensing camera provided in this embodiment includes two major parts: a flip unit and an deployable unit.

[0043] like Figure 1 , Figure 2 As shown, the first-level flip mechanism, the first-level unfolding mechanism, the second-level flip mechanism, the second-level unfolding mechanism and the third-level flip mechanism are stacked and connected in sequence from top to bottom; the first-level flip mechanism, the second-level flip mechanism and the third-level flip mechanism have the same structure; the first-level unfolding mechanism and the second-level unfolding mechanism have the same structure. When the flip mechanism is folded, the upper and lower flip plates are arranged in parallel, and the unfolding mechanism is composed of a plurality of hinged triangular prism unfolding units. The three flip mechanisms are stacked upward in sequence, and the two adjacent flip mechanisms are connected through the unfolding mechanism, that is, the lower end surface of the unfolding mechanism is connected to the upper flip plate of the flip mechanism below, and the upper end surface is connected to the lower flip plate of the upper flip mechanism. When the flip mechanism is unfolded, the upper and lower flip plates are arranged vertically, which can change the unfolding direction of the unfolding mechanism and rotate 90 degrees.

[0044] In the flip unit, the primary flip mechanism is composed of a lower flip plate 1, a motor assembly 2, a transmission shaft 3, a crank 4, a connecting rod 5, and an upper flip plate 6. The motor assembly 2 provides torque for the primary flip mechanism, the transmission shaft 3, the crank 4, and the connecting rod 5 transmit force for the primary flip mechanism, and the upper flip plate 6 is the flip object.

[0045] The first-stage unfolding mechanism is composed of a connecting frame assembly 7, a folding rod assembly 8, a volute spring assembly 9, a tension cable assembly 10, and a speed control motor assembly 11.

[0046] like Figure 3 As shown, the flipping mechanism includes a lower flip plate 1, a motor assembly 2, a transmission shaft 3, a crank 4, a connecting rod 5 and an upper flip plate 6; wherein the motor assembly 2 provides torque to drive the transmission shaft 3 to move, and drives the upper flip plate 6 to flip by driving the crank 4 and the connecting rod 5; when it is detected that the upper flip plate 6 has rotated into place, the motor assembly 2 stops working.

[0047] like Figure 4 As shown, the connecting frame assembly 7 includes a root hinge seat 12 and a first carbon fiber rod 13. There are three root hinge seats 12 and three first carbon fiber rods 13, and the hinge seats are distributed at three points of the triangle. The first carbon fiber rod 13 is located at the edge, and the two ends are respectively fixed to the root hinge seat to provide a support for the extension mechanism.

[0048] like Figure 5 As shown, the folding rod assembly 8 includes a root hinge 14 and a second carbon fiber tube 15; the second carbon fiber tube 15 is bonded and fixedly connected to the root hinge 14, and the two second carbon fiber tubes 15 are placed in parallel up and down in the folded state, and the upper and lower root hinges 14 are respectively connected to the root hinge seats 12 in the upper and lower connecting frame assemblies 7 through a rotating pair, providing support for the extension mechanism.

[0049] like Figure 6 , Figure 7 As shown, the scroll spring assembly 9 includes an active flap hinge 17, a driven flap hinge 16, a hinge rotating shaft 18, a deep groove ball bearing 19, a scroll spring outer end fixed shaft 20, a scroll spring 21 and a bearing cover 22; the hinge rotating shaft 18 is connected to the active flap hinge 17 through a key, and its two end opening sections are connected to the inner end of the scroll spring and fixed by a clamping nut; after the hinge rotating shaft 18 passes through the rotating holes of the active flap hinge and the driven flap hinge, it passes through two deep groove ball bearings 19 at the same time, and the right side is clamped and axially positioned by the bearing cover 22, and the bearing cover is connected to the outer end of the driven flap hinge 16 by a screw; the outer end of the scroll spring is fixed to the scroll spring outer end fixed shaft 20 by a hexagon socket screw; the scroll spring outer end fixed shaft 20 is connected to the driven flap, and axial positioning is achieved by a set screw.

[0050] like Figure 8 , Fig. 9 As shown, the tension cable assembly 10 includes a tension cable 23, a tension cable hinge 24, a rotary shaft 25, and a tension cable joint 32; the tension cable joint 32 passes through the hole of the tension cable hinge 24, and since the diameter of the large end of the joint is larger than the diameter of the hole, it will not pass out, and the tension cable 23 passes through the hole of the tension cable joint 32, and the thin end of the tension cable joint 32 is compressed and deformed by pressure to clamp the tension cable 23, and the thin end of the rotary shaft 25 is threaded, and after passing through the rotary hole of the tension cable hinge 24, it is screwed into the threaded hole of the bottom frame and fixed. The tension cable 23 of the deployment mechanism plays an important role in eliminating joint clearance and improving rigidity.

[0051] like Fig.10 As shown, the speed control motor assembly 11 includes a speed control rope steering mechanism 26, a drum 27, a spline 28, a speed control rope 29, a motor 30 and a mounting seat 31. The speed control rope steering mechanism 26 is fixedly connected to the mounting seat, and the speed control rope 29 is wound around the pulley thereon and changes direction before being wound around the drum 27. The motor 30 is connected to the mounting seat 31 by screws, and the output end is connected to the spline 28. The other end of the spline 28 is inserted into the spline hole of the drum 27. The other end of the drum 27 has a thread that matches the threaded hole at the left end of the mounting seat 31. When the motor drives the drum to rotate, the drum can move left and right along the mounting seat 31. Because the position of the speed control rope 29 does not change after passing through the steering mechanism, the movement of the drum can make the speed control rope 29 be wound around the drum in sequence to avoid the rope from being entangled and knotted. The main function of the speed control motor assembly 11 is to control the deployment speed of the extension mechanism, so that the deployment process of the extension mechanism is smooth and impact-free.

[0052] The working process of the large secondary mirror deployable device of the space optical remote sensing camera is as follows:

[0053] When fired, the entire mechanism is in a folded position;

[0054] After entering the orbit, the motor assembly 2 of the first-level flipping mechanism is controlled by a signal, the motor works, drives the transmission shaft 3 to move, and then drives the crank 4, the connecting rod 5, and the upper flip plate 6 to flip;

[0055] After the upper flip plate 6 rotates to the right position, the motor assembly 2 of the first-stage flip mechanism stops working;

[0056] The motor unit of the first-stage unfolding mechanism is controlled by the signal, the motor 30 works, drives the spline 28 and the roller 27 to rotate, and the speed control rope 29 begins to be slowly released. At this time, the vortex spring 21 in the vortex spring assembly 9 releases its elastic potential energy; the first-stage unfolding mechanism begins to unfold slowly;

[0057] When the first-stage deployment mechanism is deployed in place, the first-stage deployment mechanism motor unit stops working. At this time, the tension cable 23 in the tension cable assembly 10 is tightened, which plays an important role in eliminating the joint gap and improving the rigidity.

[0058] The signal is used to control the motor unit of the secondary flipping mechanism, the motor works, drives the transmission shaft to move, and then drives the crank and connecting rod, and the upper flipping plate flips;

[0059] After the upper flip plate 6 rotates to the right position, the motor assembly of the secondary flip mechanism stops working;

[0060] The signal is used to control the motor unit of the secondary deployment mechanism, the motor works, drives the spline and the drum to rotate, and the speed control rope begins to be slowly released. At this time, the vortex spring in the vortex spring assembly releases its elastic potential energy, and the secondary deployment mechanism begins to slowly deploy;

[0061] When the secondary deployment mechanism is deployed in place, the secondary deployment mechanism motor unit stops working. At this time, the tension cable in the tension cable assembly is tightened, which plays an important role in eliminating the joint gap and improving the rigidity.

[0062] The three-stage flip mechanism motor unit is controlled by the signal, the motor works, drives the transmission shaft to move, and then drives the crank and connecting rod to flip the upper flip plate. After the upper flip plate rotates to the right position, the three-stage flip mechanism motor assembly stops working;

[0063] At this point, the entire space optical remote sensing camera secondary mirror deployable mechanism has been unfolded. This deployment mechanism has completed the two-dimensional plane deployment of the space optical remote sensing camera secondary mirror deployable mechanism through 3 flips and 2 unfoldings, and reached a specific position.

[0064] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

[0065] The contents not described in detail in the specification of the present invention belong to the common knowledge of the professionals in this field.

Claims

1. A large secondary mirror deployable device for a space optical remote sensing camera, characterized in that: include: A plurality of turning mechanisms and a plurality of unfolding mechanisms; wherein the plurality of turning mechanisms are stacked and arranged in sequence, and two adjacent turning mechanisms are connected via the unfolding mechanism; the turning mechanism comprises a motor assembly (2), a transmission shaft (3), a crank (4), a connecting rod (5), an upper turning plate (6) and a lower turning plate (1); the lower end surface of the unfolding mechanism is connected to the upper turning plate (6) of the turning mechanism below, and the upper end surface is connected to the lower turning plate (1) of the turning mechanism above; when the turning mechanism is unfolded, the upper turning plate (6) and the lower turning plate (1) are arranged vertically; when the turning mechanism is folded, the upper turning plate (6) and the lower turning plate (1) are arranged parallelly; the motor assembly (2) provides a torque for the transmission shaft (3), drives the transmission shaft (3) to move, and drives the upper turning plate (6) to turn by driving the crank (4) and the connecting rod (5); when it is detected that the upper turning plate (6) has rotated into place, the motor assembly (2) stops working.

2. The large secondary mirror deployable device for a space optical remote sensing camera according to claim 1, characterized in that: The unfolding mechanism comprises an extension mechanism and a speed control motor assembly (11); wherein the extension mechanism is composed of a plurality of extension units connected in series; the extension unit is a triangular prism structure; the speed control motor assembly (11) comprises a speed control motor and a speed control rope; one end of the speed control rope is connected to the speed control motor and installed at one end of the extension mechanism; the other end of the speed control rope is connected to the other end of the extension mechanism; the speed control motor controls the release length of the speed control rope to pull the extension mechanism to an unfolding height.

3. The large secondary mirror deployable device for a space optical remote sensing camera according to claim 2, characterized in that: The unfolding unit comprises a connecting frame assembly (7), a folding rod assembly (8), a scroll spring assembly (9) and a tension cable assembly (10); wherein the scroll spring assembly (9) is installed in the middle of the folding rod assembly (8) to provide a driving torque for the folding rod assembly (8); the two connecting frame assemblies (7) are respectively the upper and lower surfaces of the triangular prism structure; the upper and lower surfaces of the triangular prism structure are connected by three folding rod assemblies (8) to provide a supporting function; the two ends of the tension cable assembly (10) are respectively connected to the diagonally opposite corners of the quadrilateral on the side of the triangular prism, and are arranged crosswise.

4. The large secondary mirror deployable device for a space optical remote sensing camera according to claim 3, characterized in that: The connecting frame assembly (7) comprises a root hinge seat (12) and a first carbon fiber rod (13); wherein there are three root hinge seats (12) and three first carbon fiber rods (13), the first carbon fiber rods (13) form a triangle, and the two ends of each first carbon fiber rod (13) are respectively fixedly connected to a root hinge seat (12).

5. The large secondary mirror deployable device for a space optical remote sensing camera according to claim 4, characterized in that: The folding rod assembly (8) comprises a root hinge (14) and two second carbon fiber tubes (15); wherein the root hinge (14) is bonded and fixedly connected to the ends of the two second carbon fiber tubes (15), and the two second carbon fiber tubes (15) are in a parallel state when in a folded state; and the root hinge (14) is respectively connected to the root hinge seats (12) in the upper and lower connecting frame assemblies (7) by rotation.

6. The large secondary mirror deployable device for a space optical remote sensing camera according to claim 1, characterized in that: The scroll spring assembly (9) comprises an active flap hinge (17), a driven flap hinge (16), a hinge rotating shaft (18), a deep groove ball bearing (19), a scroll spring outer end fixed shaft (20), a scroll spring (21) and a bearing cover (22); wherein the hinge rotating shaft (18) is connected to the active flap hinge (17) via a key, and the two ends of the hinge rotating shaft (18) are respectively connected to the inner ends of the two scroll springs (21); and a rotating shaft (18) is provided inside the active flap hinge (17) and the driven flap hinge (16). The hinge pivot shaft (18) passes through the pivot holes of the active flap hinge (17) and the driven flap hinge (16), and then passes through two deep groove ball bearings (19) at the same time; the right side is pressed and axially positioned by a bearing cover (22), and the bearing cover (22) is connected to the outer end of the driven flap hinge (16); the outer end of the scroll spring (21) is fixed to the outer end fixing shaft (20) of the scroll spring; the outer end fixing shaft (20) of the scroll spring is connected to the driven flap hinge (16), and axial positioning is achieved by a set screw.

7. The large secondary mirror deployable device for a space optical remote sensing camera according to claim 3, characterized in that: The tension cable assembly (10) comprises a tension cable (23), a tension cable hinge (24), a rotating shaft (25) and a tension cable joint (32); wherein the two ends of the tension cable joint (32) are respectively a thick rod and a thin rod; a through hole is provided at one end of the thin rod; the thick rod is inserted into a groove provided in the middle of the tension cable hinge (24); the tension cable (23) passes through the through hole of the tension cable joint (32), and the thin rod of the tension cable joint (32) is compressed and deformed by pressure to clamp the tension cable (23); the thin end of the rotating shaft (25) is threaded, passes through the rotating hole provided in the tension cable hinge (24), and is screwed into the threaded hole provided on the connecting frame assembly (7) for fixation.

8. The large secondary mirror deployable device for a space optical remote sensing camera according to claim 1, characterized in that: The speed control motor assembly (11) comprises a speed control rope steering mechanism (26), a drum (27), a spline (28), a speed control rope (29), a motor (30) and a mounting seat (31); wherein the speed control rope steering mechanism (26) is fixedly connected to the mounting seat (31) and a pulley is arranged; the speed control rope (29) is wound around the pulley and then changed in direction and then wound around the drum (27); the motor (30) is connected to the mounting seat (31); a key hole is arranged on the inner side of one end of the drum (27) and a thread is arranged on the other end; the spline (28) is fixedly connected to the mounting seat (31) and a pulley is arranged on the inner side of the drum (27). ) is connected to a motor (30), and the other end is inserted into a spline hole of a drum (27); a threaded end of the drum (27) is matched with a threaded hole provided on a mounting seat (31); when the motor (30) drives the drum (27) to rotate, the drum (27) moves left and right along the mounting seat (31); the position of the speed control rope (29) remains unchanged after passing through the speed control rope steering mechanism (26), and the drum (27) moves so that the speed control rope (29) is sequentially wound around the drum (27), thereby preventing the speed control rope (29) from being entangled and knotted.

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