Two-stage suspension two-dimensional pointing precise adjustable large-mass optical load gravity unloading device

Abstract

The invention discloses a two-stage suspension two-dimensional pointing precision adjustable large-mass optical load gravity unloading device, and belongs to the technical field of optical engineering and precision machine.The two-stage suspension two-dimensional pointing precision adjustable large-mass optical load gravity unloading device comprises a fixing base, a first fixing frame is arranged on the fixing base, a two-dimensional precision rotating mechanism is arranged on the first fixing frame, and a second fixing frame is arranged on the second fixing frame; the two-dimensional precise rotating mechanism comprises two-dimensional rotating shafts, the two-dimensional rotating shafts are symmetrically arranged in the first fixing frame, a large-mass optical load is fixedly arranged between the two two-dimensional rotating shafts, and a second-stage torsion balance mechanism is arranged on the first fixing frame. By the adoption of the two-stage suspension two-dimensional pointing precise adjustable large-mass optical load gravity unloading device, the gravity unloading state can be kept, and meanwhile the precise pointing adjusting performance of the large-mass optical load in the two-dimensional direction is not affected at all.

Description

Technical Field

[0001] The invention relates to the fields of optical engineering and precision mechanical technology, and in particular to a two-level suspended two-dimensional pointing precision adjustable large-mass optical load gravity unloading device. Background Art

[0002] In some typical space application tasks such as space gravitational wave detection and precision optical remote sensing, precision drivers are needed to drive large-mass optical payloads to perform angular deflection around one-dimensional or two-dimensional precision rotation axes, so as to achieve precise adjustment of the spatial pointing direction of the large-mass optical payload in one-dimensional or two-dimensional directions.

[0003] For example, in a typical space gravitational wave detection mission, it is necessary to form an intersatellite laser ranging interferometer between multiple satellites to accurately measure the distance change between long-distance satellites and then solve the gravitational wave data; among them, the intersatellite laser ranging interferometer measurement optical path on each satellite is fixedly connected to form a large-mass optical payload of about 80kg, and the pointing direction of the large-mass payload needs to be precisely adjusted in two dimensions to realize the scanning and capture function of the intersatellite laser beam and the precise adjustment of the pointing direction of the intersatellite laser beam during scientific measurement. The adjustment range of the two-dimensional pointing reaches ±5mrad, and the adjustment sensitivity is better than 10nrad. In a typical precision optical remote sensing space application mission, it is necessary to adjust the pointing direction of a large-mass optical remote sensing camera weighing tens of kilograms, accurately align it with the target area and keep tracking, and the pointing alignment and tracking accuracy are required to reach the micro-arc level.

[0004] In the above-mentioned space missions, these large-mass optical payloads work in a microgravity environment after entering orbit with the spacecraft. Therefore, when a precision driver is used to drive the large-mass optical payload to deflect around a one-dimensional or two-dimensional precision axis, the precision axis is only affected by the driving force or torque generated by the driver, and is not affected by the gravity of the large-mass optical payload itself. However, the assembly and testing of such large-mass optical payloads are all carried out in a ground gravity environment. In order to test its high-precision pointing adjustment performance at the micro-radian to nano-radian level around the precision axis, it is necessary to unload the gravity of the large-mass optical payload in the ground gravity environment to avoid the gravity acting on the precision axis, and it is necessary to avoid the gravity unloading device or mechanism from affecting the pointing adjustment performance, so as to ensure that the high-precision pointing adjustment performance of the large-mass optical payload in the space microgravity environment can be accurately and reliably tested in the ground environment.

[0005] The current gravity unloading methods are divided into two categories: active gravity compensation and passive gravity compensation. Active gravity compensation uses sensors and actuators to monitor and adjust the telescope structure in real time to compensate for changes caused by gravity. The compensation accuracy is high, but the structure is complex and easy to damage, which is not suitable for space exploration missions. Passive gravity compensation uses springs, pneumatic devices, suspension wires, etc. to partially offset the impact of gravity on the detector. It can be subdivided into drop tower method, parabola method, water flotation method, air flotation method, suspension method, etc. The drop tower method and parabola method are to make the experimental device do free fall or horizontal projection to achieve a microgravity environment. The construction cost is high, and the duration of the microgravity environment is too short. The water flotation method uses the buoyancy of water to offset the gravity of the spacecraft, which can achieve a microgravity environment for any time. The disadvantage is that the experimental equipment needs to be specially waterproofed. The air flotation method uses gas to lift the experimental equipment, which requires precise control of the flow rate of the ejected airflow, and the equipment processing, installation and debugging are more troublesome. The suspension method is to use suspension wires to suspend the experimental equipment and use the tension of the suspension wires to balance gravity. It is a common way to simulate microgravity. The suspension method uses the tension of the suspension wires to balance the gravity on the detector. By accurately calculating the position of the suspension wires, the suspension method can provide accurate gravity unloading to ensure that the optical components and structures of the optical load are not deformed by gravity. The more suspension wires there are, the smaller the stress deformation near the connection point of a single suspension wire, but the more complex the suspension system. The commonly used suspension wire system currently has less than 10 suspension wires. The suspension wire method is a passive support system that does not involve active mechanical components, reduces possible mechanical vibration and interference, has a simple structure, high reliability, and low maintenance costs.

[0006] However, in space gravitational wave detection, precision optical remote sensing and other tasks, it is required that when gravity unloading is performed on a large mass optical payload, the gravity unloading device or mechanism needs to minimize the impact on the high-precision pointing adjustment performance of the large mass optical payload at the micro-radian to nano-radian level. In the above existing gravity unloading methods, when considering gravity unloading, the impact of the gravity unloading device or mechanism on the high-precision pointing adjustment performance is not considered, and it cannot meet the application requirements of ground testing of the two-dimensional precision pointing adjustment performance of large mass optical payloads in space gravitational wave detection, precision optical remote sensing and other tasks. Summary of the invention

[0007] The purpose of the present invention is to provide a two-stage suspended two-dimensional pointing precision adjustable large-mass optical load gravity unloading device to solve the problems mentioned in the background technology.

[0008] To achieve the above object, the present invention provides a gravity unloading device for a large-mass optical payload with two-stage suspension and two-dimensional pointing precision adjustment, including a fixed base, on which a first fixed frame is provided, on which a two-dimensional precision rotation mechanism is provided, the two-dimensional precision rotation mechanism includes a two-dimensional rotating shaft, the two-dimensional rotating shafts are symmetrically arranged inside the first fixed frame, and a large-mass optical payload is fixedly arranged between the two two-dimensional rotating shafts, and a two-stage torsion balance mechanism is provided on the first fixed frame.

[0009] Preferably, a connecting frame is provided on one side of the first fixed frame, a precision driver is provided on the connecting frame, and the precision driver is connected to the large-mass optical payload.

[0010] Preferably, the connecting frame is arranged in a "C" shape.

[0011] Preferably, the two-stage torsion balance mechanism includes a second fixed frame, a first torsion wire and a first suspension beam, the second fixed frame is arranged above the first fixed frame, the top end of the first torsion wire is fixedly arranged on the second fixed frame, and the bottom end of the first torsion wire is fixedly connected to the middle part of the first suspension beam.

[0012] Preferably, the arrangement direction of the first suspension beam is parallel to the pointing direction of the large-mass optical payload.

[0013] Preferably, the two-stage torsion balance mechanism further includes a first second-stage torsion wire and a second second-stage torsion wire, the top end of the first second-stage torsion wire is connected to one end of the first suspension beam, the bottom end of the first second-stage torsion wire is connected to the large-mass optical payload, and the top end of the second second-stage torsion wire is fixedly connected to the other end of the first suspension beam.

[0014] Preferably, the first second-stage torsion wire is located on the vertical line where the center of mass of the large-mass optical payload is located.

[0015] Preferably, a counterweight is connected to the bottom end of the second second-stage torsion wire.

[0016] Preferably, the mass of the counterweight is equal to the mass of the large-mass optical payload.

[0017] Therefore, the present invention adopts the above-mentioned gravity unloading device for a large-mass optical payload with two-stage suspension and two-dimensional pointing precision adjustment, and has the following beneficial effects: the two-stage torsion balance is arranged in a specific way, while realizing the gravity unloading of the large-mass optical payload, it has no impact on the precision pointing adjustment performance of the large-mass optical payload in the two-dimensional direction, so as to achieve the purpose of simulating the precision pointing adjustment performance of the large-mass optical payload in tasks such as space gravitational wave detection and precision optical remote sensing on the ground.

[0018] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of an embodiment of the present invention; Figure 2 A top view of an embodiment of the present invention; Figure 3 A side view of an embodiment of the present invention; Figure 4 This is a structural diagram of an embodiment of the present invention in which an angle deflection occurs in the horizontal direction; Figure 5 A structural diagram of an embodiment of the present invention in which an angle deflection occurs in the vertical direction; Reference numerals 1. Fixed base; 2. Fixed frame one; 3. Two-dimensional precision rotation mechanism; 4. Large mass optical load; 5. Secondary torsion balance mechanism; 51. Fixed frame two; 52. Primary torsion wire; 53. Primary cantilever beam; 54. Secondary torsion wire one; 55. Secondary torsion wire two; 6. Connecting frame; 7. Precision driver; 8. Counterweight; T1. Tension of secondary torsion wire one on large mass optical load; G. Gravity of large mass optical load; m. Mass of large mass optical load; g. Acceleration of gravity; α. Deflection angle of gravity unloading device in horizontal direction; β. Deflection angle of gravity unloading device in vertical direction. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0021] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0022] Example like Figure 1-5As shown in the figure, the present invention provides a gravity unloading device for a large-mass optical payload with two-stage suspension and two-dimensional pointing precision adjustment, which includes a fixed base 1. A fixed frame one 2 is arranged on the fixed base 1. A two-dimensional precision rotation mechanism 3 is arranged on the fixed frame one 2. The two-dimensional precision rotation mechanism 3 includes a two-dimensional rotating shaft, and the two-dimensional rotating shafts are symmetrically arranged inside the fixed frame one 2. A large-mass optical payload 4 is fixedly arranged between the two two-dimensional rotating shafts. A two-stage torsion balance mechanism 5 is arranged on the fixed frame one 2.

[0023] A connecting frame 6 is arranged on one side of the fixed frame one 2. The connecting frame 6 is arranged in a "C" shape structure, and a precision driver 7 is arranged on the connecting frame 6. The precision driver 7 is connected to the large-mass optical payload 4. The driving point of the precision driver 7 acts on the large-mass optical payload 4. The precision driver 7 generates a driving force to drive the large-mass optical payload 4, so that the pointing direction of the large-mass optical payload 4 deflects by a high-precision two-dimensional angle around the two-dimensional rotating shaft of the two-dimensional precision rotation mechanism 3.

[0024] The two-stage torsion balance mechanism 5 includes a fixed frame two 51, a first-stage torsion wire 52 and a first-stage suspension beam 53. The fixed frame two 51 is arranged above the fixed frame one 2. The top end of the first-stage torsion wire 52 is fixedly arranged on the fixed frame two 51, and the bottom end of the first-stage torsion wire 52 is fixedly connected to the middle part of the first-stage suspension beam 53. The first-stage torsion wire 52 is arranged coplanar with the plane of the two-dimensional rotating shaft of the two-dimensional precision rotation mechanism 3. When the pointing direction of the large-mass optical payload 4 deflects by a high-precision two-dimensional angle around the two-dimensional rotating shaft of the two-dimensional precision rotation mechanism 3, the direction of the first-stage suspension beam 53 changes synchronously with the two-dimensional pointing direction of the large-mass optical payload 4, so that the pulling force direction of the second-stage torsion wire one 54 on the large-mass optical payload 4 always remains in the plumb line direction passing through the centroid of the large-mass optical payload 4. Thus, while maintaining the gravity unloading state, it has no influence on the precision pointing adjustment performance of the large-mass optical payload 4 in the two-dimensional direction. The arrangement direction of the first-stage suspension beam 53 is parallel to the pointing direction of the large-mass optical payload 4.

[0025] The two-stage torsion balance mechanism 5 further includes a second-stage torsion wire one 54 and a second-stage torsion wire two 55. The top end of the second-stage torsion wire one 54 is connected to one end of the first-stage suspension beam 53, and the bottom end of the second-stage torsion wire one 54 is connected to the large-mass optical payload 4. The top end of the second-stage torsion wire two 55 is fixedly connected to the other end of the first-stage suspension beam 53. The second-stage torsion wire one 54 is located on the plumb line where the centroid of the large-mass optical payload 4 is located.

[0026] A counterweight 8 is connected to the bottom end of the second-stage torsion wire two 55. The mass of the counterweight 8 is equal to the mass of the large-mass optical payload 4, so that the gravity of the large-mass optical payload 4 is balanced with the gravity of the counterweight 8, realizing the gravity unloading of the large-mass optical payload 4.

[0027] Therefore, the present invention adopts the above-mentioned two-stage suspended two-dimensional pointing precisely adjustable large-mass optical load gravity unloading device, which has no effect on the precise pointing adjustment performance of the large-mass optical load in the two-dimensional direction while maintaining the gravity unloading state.

[0028] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A two-stage suspended two-dimensional pointing precision adjustable large mass optical load gravity unloading device, characterized by: It includes a fixed base, on which a first fixed frame is provided. A two-dimensional precision rotation mechanism is provided on the first fixed frame. The two-dimensional precision rotation mechanism includes a two-dimensional rotating shaft, which is symmetrically arranged inside the first fixed frame. A large-mass optical payload is fixedly arranged between the two two-dimensional rotating shafts. A secondary torsion balance mechanism is provided on the first fixed frame.

2. The two-stage suspended two-dimensional pointing precision adjustable large mass optical load gravity unloading device according to claim 1 is characterized by: A connecting frame is provided on one side of the first fixed frame. A precision driver is provided on the connecting frame, and the precision driver is connected to the large-mass optical payload.

3. The two-stage suspended two-dimensional pointing precision adjustable large mass optical load gravity unloading device according to claim 2 is characterized by: The connecting frame is arranged in a "C" shape structure.

4. The two-stage suspended two-dimensional pointing precision adjustable large mass optical load gravity unloading device according to claim 1 is characterized by: The secondary torsion balance mechanism includes a second fixed frame, a first torsion wire and a first suspension beam. The second fixed frame is arranged above the first fixed frame. The top end of the first torsion wire is fixedly arranged on the second fixed frame, and the bottom end of the first torsion wire is fixedly connected to the middle part of the first suspension beam.

5. The two-stage suspended two-dimensional pointing precision adjustable large mass optical load gravity unloading device according to claim 4 is characterized by: The arrangement direction of the first suspension beam is parallel to the pointing direction of the large-mass optical payload.

6. The two-stage suspended two-dimensional pointing precision adjustable large mass optical load gravity unloading device according to claim 5 is characterized by: The secondary torsion balance mechanism further includes a first secondary torsion wire and a second secondary torsion wire. The top end of the first secondary torsion wire is connected to one end of the first suspension beam, the bottom end of the first secondary torsion wire is connected to the large-mass optical payload, and the top end of the second secondary torsion wire is fixedly connected to the other end of the first suspension beam.

7. The two-stage suspended two-dimensional pointing precision adjustable large mass optical load gravity unloading device according to claim 6 is characterized by: The first secondary torsion wire is located on the vertical line where the center of mass of the large-mass optical payload is located.

8. The two-stage suspended two-dimensional pointing precision adjustable large mass optical load gravity unloading device according to claim 7 is characterized by: A counterweight is connected to the bottom end of the second secondary torsion wire.

9. The two-stage suspended two-dimensional pointing precision adjustable large mass optical load gravity unloading device according to claim 8 is characterized by: The mass of the counterweight is equal to the mass of the large-mass optical payload.

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