A two-dimensional pointing mechanism with both load-bearing and vibration isolation capabilities

Abstract

A two-dimensional pointing mechanism with both load-bearing and vibration isolation capabilities, comprising upper and lower platforms, voice coil motors, and a high-static low-motion actuator; the voice coil motors are distributed at 90-degree intervals, the voice coil motor movers are connected to the upper platform through connectors and flexible hinges, and there is no connection contact between the stators, movers, and excitation coils, finally forming a two-dimensional pointing decoupled structure form. By driving the diagonal voice coil motors with currents in opposite directions, the two-dimensional pointing function is realized; the high-static low-motion actuator is installed at the center of the upper and lower platforms through flexible hinges; at static, the high-static low-motion actuator has a large static stiffness, which can realize the static load-bearing of the two-dimensional pointing mechanism; when there is an external disturbance acting on the lower platform, in the dynamic load transfer, the high-static low-motion actuator realizes the quasi-zero stiffness function, isolates the high-frequency part of the dynamic load transmitted from the lower tabletop, and realizes the dynamic vibration isolation function. The present invention can realize that the two-dimensional pointing mechanism has both load-bearing capacity and vibration isolation function at the same time.

Description

Technical Field

[0001] The present invention relates to the field of high-precision pointing control of space optical payloads, and specifically relates to a two-dimensional pointing mechanism with both bearing and vibration isolation capabilities. Background Art

[0002] With the continuous development of the space application field, future space optical payload technologies (such as reconnaissance photographic satellites, astronomical telescopes, etc.) will develop towards higher pointing accuracies. Existing two-dimensional pointing mechanisms either do not have vibration isolation capabilities. To ensure that the micro-vibrations generated on the satellite body are not transmitted to the optical payload, a vibration isolation platform must be installed between the two-dimensional pointing mechanism and the satellite body, which increases the complexity of the system; or they do not have bearing capabilities. In the launch phase, the upper and lower platforms of the two-dimensional pointing mechanism must be locked with a locking mechanism and then unlocked in space, which also increases the structural weight and complexity. Summary of the Invention

[0003] To solve the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a two-dimensional pointing mechanism with both bearing and vibration isolation capabilities. This structure has static bearing capacity and dynamic vibration isolation capacity, thus ensuring that it does not need to be locked during the launch phase and can isolate vibrations in space, reducing the impact of satellite body micro-vibrations on the optical payload, and thereby improving the two-dimensional pointing accuracy of the optical payload.

[0004] To achieve the above object, the present invention adopts the following technical solution:

[0005] A two-dimensional pointing mechanism with both bearing and vibration isolation capabilities, comprising an upper platform 1 and a lower platform 2, a voice coil motor 3 and a high-static low-actuation actuator 4 arranged between the upper platform 1 and the lower platform 2, wherein the high-static low-actuation actuator 4 is arranged in the middle, and the voice coil motor 3 is symmetrically arranged around the high-static low-actuation actuator 4;

[0006] The voice coil motor 3 includes a stator 8, a mover 9 and an excitation coil 10; the excitation coil 10 is wound around the mover 9;

[0007] The high-static low-actuation actuator 4 includes an adjustable bottom cover 11, a housing 12, an upper cover 13, screws 14, a spring 15, a crimping sleeve 16, an outer permanent magnet 17, a sleeve 18, an inner permanent magnet 19, a gland 20, and a screw rod 21. The adjustable bottom cover 11 is connected to the housing 12 in a threaded form, and the spring 15 is adjusted according to the weight of the upper platform 1. The outer permanent magnet 17 is embedded in the housing 12 and is connected to the housing 12 by the upper cover 13 through the screws 14, while also pressing the outer permanent magnet 17. The inner permanent magnet 19 is placed in the sleeve 18, pressed by the gland 20, then sleeved on the screw rod 21, and then the crimping sleeve 16 is threadedly connected to the screw rod 21, while pressing the gland 20. The spring 15 is sleeved on the screw rod 21 and is pressed and adjusted by the crimping sleeve 16 and the adjustable bottom cover 11. The screw rod 21 has a clearance fit with the upper cover 13.

[0008] By driving two voice coil motors 3 at opposite corners in opposite directions of current, a two-dimensional pointing function is achieved. When static, the high-static low-actuation actuator 4 has the ability to carry a large mass due to the positive stiffness of the spring 15. When there is an external disturbance acting on the lower platform 2, in the dynamic load transfer, the high-static low-actuation actuator 4 will produce a quasi-zero stiffness effect under the combined action of the positive stiffness of the spring 15 and the negative stiffness formed by the outer permanent magnet 17 and the inner permanent magnet 19, thereby isolating the high-frequency part of the dynamic load transmitted from the lower platform 2 and achieving the dynamic vibration isolation function.

[0009] The voice coil motors 3 are distributed at an angular interval of 90 degrees, forming a two-dimensional pointing decoupling structure. Except for the inner permanent magnet 19 and the outer permanent magnet 17, other components of the two-dimensional pointing mechanism are made of non-magnetic materials.

[0010] Both the inner permanent magnet 19 and the outer permanent magnet 17 are radially magnetized, and the magnetization directions are opposite.

[0011] There is no connection contact between the stator 8, the mover 9, and the excitation coil 10, so that the force transfer path between the upper and lower platforms of the entire two-dimensional pointing mechanism can only be transmitted through the high-static low-actuation actuator 4.

[0012] The voice coil motor 3 is connected to the upper platform 1 through a connecting piece 5 and a first flexible hinge 6, and the high-static low-actuation actuator 4 is connected to the upper platform 1 through a second flexible hinge 7.

[0013] Compared with the prior art, the present invention has the following advantages:

[0014] 1) In the present invention, the high-static low-actuation actuator is used to connect the central parts of the upper and lower platforms, enabling the two-dimensional pointing mechanism to have both the load-bearing capacity when static and the vibration isolation ability when the lower platform is disturbed.

[0015] 2) In the present invention, the bottom cover of the high-static low-actuation actuator is connected to the outer shell in a threaded form. According to the mass of the upper platform, by adjusting the relative position between the bottom cover and the outer shell, it can adapt to the change in the relative position between the inner permanent magnet and the outer permanent magnet caused by the change in the mass of the upper platform, and adjust the middle cross-section of the inner permanent magnet and the outer permanent magnet to coincide. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 FIG. is a schematic structural diagram of a two-dimensional pointing mechanism of the present invention with both load-bearing and pointing capabilities.

[0017] Figure 2 FIG. is a side view of a two-dimensional pointing mechanism of the present invention with both load-bearing and pointing capabilities.

[0018] Figure 3 FIG. is a cross-sectional view of the internal structure of a voice coil motor.

[0019] Figure 4 FIG. is a cross-sectional view of the internal structure of a high-static low-actuation actuator. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] As Figure 1 and 2 shown, a two-dimensional pointing mechanism of the present invention with both load-bearing and vibration isolation capabilities includes an upper platform 1, a lower platform 2, a voice coil motor 3, a high-static low-actuation actuator 4, a connecting member 5, and a first flexible hinge 6 and a second flexible hinge 7. Among them, the voice coil motor 3 and the high-static low-actuation actuator 4 are arranged between the upper platform 1 and the lower platform 2. The high-static low-actuation actuator 4 is arranged in the middle, and the voice coil motor 3 is symmetrically arranged around the high-static low-actuation actuator 4. The voice coil motor 3 is connected to the upper platform 1 through the connecting member 5 and the first flexible hinge 6, and the high-static low-actuation actuator 4 is connected to the upper platform 1 through the second flexible hinge 7.

[0022] As Figure 3 shown, the voice coil motor 3 includes a stator 8, a mover 9, and an excitation coil 10; the excitation coil 10 is wound around the mover 9.

[0023] As Figure 4As shown, the high-static low-actuation actuator 4 includes an adjustable bottom cover 11, an outer shell 12, an upper cover 13, screws 14, a spring 15, a crimping sleeve 16, an outer permanent magnet 17, a sleeve 18, an inner permanent magnet 19, a gland 20, and a screw rod 21; the adjustable bottom cover 11 is connected to the outer shell 12 in a threaded form, and the spring 15 is adjusted according to the weight of the upper platform 1; the outer permanent magnet 17 is embedded in the outer shell 12 and is connected to the outer shell 12 by the upper cover 13 through the screws 14, while realizing the pressing of the outer permanent magnet 17; the inner permanent magnet 19 is placed in the sleeve 18, pressed by the gland 20, then sleeved on the screw rod 21, and then the crimping sleeve 16 is threadedly connected to the screw rod 21, while pressing the gland 21, the spring 15 is sleeved on the screw rod 21, and the pressing adjustment is carried out by the crimping sleeve 16 and the adjustable bottom cover 11; the screw rod 21 is in small-clearance fit with the upper cover 13.

[0024] As a preferred embodiment of the present invention, there is no connection contact between the stator 8, the rotor 9, and the exciting coil 10, so that the force transmission path between the upper and lower platforms of the entire two-dimensional pointing mechanism can only pass through the high-static low-actuation actuator 4.

[0025] As a preferred embodiment of the present invention, the voice coil motor 3 is connected to the upper table 1 through the connecting piece 5 and the first flexible hinge 6, and the high-static low-actuation actuator 4 is connected to the upper table 1 through the second flexible hinge 7; the flexible hinge can eliminate the dead zone and mechanical friction during the two-dimensional pointing process, so as to obtain ultra-high-precision displacement resolution.

[0026] As a preferred embodiment of the present invention, except for the inner permanent magnet 19 and the outer permanent magnet 17, other components of the high-static low-actuation actuator are made of non-magnetic conductive materials; this can reduce the loss of magnetic flux between the inner permanent magnet 19 and the outer permanent magnet 17.

[0027] As a preferred embodiment of the present invention, both the inner permanent magnet 19 and the outer permanent magnet 17 are radially magnetized, and the magnetization directions are opposite; this forms an attractive interaction, which is beneficial to the formation of magnetic negative stiffness between the inner permanent magnet 19 and the outer permanent magnet 17.

[0028] The working principle of the present invention is as follows: The voice coil motors are distributed at an angular interval of 90 degrees, forming a two-dimensional pointing decoupled structure. By driving the diagonal voice coil motors with currents in opposite directions, the two-dimensional pointing function can be achieved. Since there is no connection or contact between the stator 8, the mover 9 and the excitation coil 10, the force transmission path between the upper and lower platforms of the entire two-dimensional pointing mechanism can only pass through the high-static low-actuation actuator 4. When the two-dimensional pointing mechanism is in a static equilibrium state, the voice coil motor part does not have a load-bearing capacity, and the mid-sections of the inner permanent magnet 19 and the outer permanent magnet 17 coincide, and the axial magnetic force of the outer permanent magnet 17 on the inner permanent magnet 19 is zero, so it will not affect the static load-bearing capacity of the spring 15, thus realizing the load-bearing function of two-dimensional pointing. When there is an external disturbance acting on the lower platform 2, similarly, the voice coil motor 3 does not have the ability to transmit dynamic forces, and the dynamic forces can only be transmitted through the high-static low-actuation actuator 4. The magnetic spring formed by the inner permanent magnet 19 and the outer permanent magnet 17 generates a large negative stiffness. After paralleling with the positive stiffness of the spring 15, the stiffness at the load balance position of the system is very small, close to zero, resulting in a very low natural frequency of the system, which plays a role in high-frequency isolation for the dynamic loads transmitted from the lower platform 2, realizing the dynamic vibration isolation function of this two-dimensional pointing mechanism.

Claims

1. A two-dimensional pointing mechanism with both load-bearing and vibration isolation capabilities, characterized in that: It includes an upper platform (1) and a lower platform (2), a voice coil motor (3) and a high-static low-actuation actuator (4) arranged between the upper platform (1) and the lower platform (2), wherein the high-static low-actuation actuator (4) is arranged in the middle, and the voice coil motors (3) are symmetrically arranged around the high-static low-actuation actuator (4); The voice coil motor (3) includes a stator (8), a mover (9) and an excitation coil (10); the excitation coil (10) is wound around the mover (9); The high-static low-actuation actuator (4) includes an adjustable bottom cover (11), a housing (12), an upper cover (13), screws (14), a spring (15), a crimping sleeve (16), an outer permanent magnet (17), a sleeve (18), an inner permanent magnet (19), a gland (20) and a screw rod (21); the adjustable bottom cover (11) is connected to the housing (12) in a threaded form to adjust the spring (15) according to the weight of the upper platform (1); the outer permanent magnet (17) is embedded in the housing (12) and is connected to the housing (12) by the upper cover (13) through the screws (14), and at the same time, the outer permanent magnet (17) is pressed tightly; the inner permanent magnet (19) is placed in the sleeve (18), pressed tightly by the gland (20), then sleeved on the screw rod (21), and then the crimping sleeve (16) is threadedly connected to the screw rod (21) to press the gland (20) tightly at the same time; the spring (15) is sleeved on the screw rod (21) and is pressed and adjusted by the crimping sleeve (16) and the adjustable bottom cover (11); the screw rod (21) has a clearance fit with the upper cover (13); There is no connection and contact between the stator (8), the mover (9) and the excitation coil (10), so that the force transmission path between the upper and lower platforms of the entire two-dimensional pointing mechanism can only be transmitted through the high-static low-actuation actuator (4); The voice coil motor (3) is connected to the upper platform (1) through a connecting piece (5) and a first flexible hinge (6), and the high-static low-actuation actuator (4) is connected to the upper platform (1) through a second flexible hinge (7); By driving two diagonal voice coil motors (3) with currents in opposite directions, the two-dimensional pointing function is realized; at static, the high-static low-actuation actuator (4) has the ability to carry large masses due to the positive stiffness of the spring (15); when there is an external disturbance acting on the lower platform (2), in the dynamic load transmission, the high-static low-actuation actuator (4) will produce a quasi-zero stiffness effect under the combined action of the positive stiffness of the spring (15) and the negative stiffness formed by the outer permanent magnet (17) and the inner permanent magnet (19), so as to isolate the high-frequency part of the dynamic load transmitted from the lower platform (2) and realize the dynamic vibration isolation function.

2. The two-dimensional pointing mechanism with both load-bearing and vibration isolation capabilities according to claim 1, characterized in that: The voice coil motors (3) are distributed at an angular interval of 90 degrees to form a two-dimensional pointing decoupling structure form.

3. The two-dimensional pointing mechanism with both load-bearing and vibration isolation capabilities according to claim 1, characterized in that: Except for the inner permanent magnet (19) and the outer permanent magnet (17), other components of the two-dimensional pointing mechanism are made of non-magnetic materials.

4. The two-dimensional pointing mechanism with both load-bearing and vibration isolation capabilities according to claim 1, characterized in that: Both the inner permanent magnet (19) and the outer permanent magnet (17) are radially magnetized, and the magnetization directions are opposite.

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