Cantilever type active and passive integrated orthogonal vibration isolation device with six degrees of freedom

Abstract

The invention provides a cantilever type active and passive integrated orthogonal vibration isolation device with six degrees of freedom. The cantilever type active and passive integrated orthogonal vibration isolation device comprises an upper platform (1), three three-joint hinges (2) which may have zero rotational stiffness, six carbon fiber rods (3), six two-joint hinges (4) which may have zero rotational stiffness, and six active and passive integrated linear vibration isolation mechanisms (5); each active and passive integrated linear vibration isolation mechanism (5) is fixedly connected with an external spacecraft; the upper platform (1) is connected with an external load; low frequency can generate low-frequency and high-frequency micro-vibration when the external spacecraft movesin a six-degree-of-freedom direction; the low-frequency and high-frequency micro-vibration is converted into axial vibration along the active and passive integrated linear vibration isolation mechanism (5) in a decoupling mode by cooperation of the three three-joint hinges (2) which may have zero rotational stiffness, the six carbon fiber rods (3) and the six two-joint hinges (4) which may have zero rotational stiffness; and the active and passive integrated linear vibration isolation mechanism (5) isolates high-frequency micro-vibration and suppresses low-frequency micro-vibration, thereby reducing the influence of micro-vibration of the external spacecraft on the stability and pointing accuracy of an external load connected with the upper platform (1).

Description

technical field [0001] The invention relates to a cantilever beam type active and passive integrated orthogonal six-degree-of-freedom vibration isolation device, which belongs to the field of multi-degree-of-freedom micro-vibration control including aerospace high-resolution earth observation and space-borne precision optical instruments. Background technique [0002] With the mission of large-scale space-based astronomical observation spacecraft and extremely high-resolution earth observation satellites, the "three supers" of optical payloads, ultra-agile maneuvering search for laser payloads, ultra-high-precision pointing, and ultra-high stability control have been proposed. control needs. The on-orbit medium-high frequency micro-vibration environment induced by the flywheel of the spacecraft body, the control torque gyroscope, the refrigerator, and the driving mechanism, as well as the low-frequency vibration of the spacecraft body caused by the large flexibility and dens...

AI Technical Summary

Problems solved by technology

[0005] In view of the large optical load active vibration isolation requirements for large output of the actuator, the weight of the voice coil motor actuator is too heavy, and the voice coil motor has no guiding device, so it is necessary to configure a linear guide rail, which further increases the weight of the single-leg actuator. Large, which limits the practical application on spacecraft

[0006] 2. Actuator backup is difficult

[0007] The voice coil motor actuator is the core actuator of active control. Due to its large size and heavy weight, it is difficult to carry out backup design for it. There is a plan to realize the actuator by changing the six-rod type of the Stewart configuration into an eight-rod type. Backup, but this undoubtedly increases the weight and complexity of the control system

[0008] 3. The elastic hinge does not achieve zero rotational stiffness

[0009] Whether it is a six-rod vibration isolation device or an eight-rod vibration isolation device, the movement of the external load relative to the spacecraft is accompanied by the extension and rotation of the rod. The vibration transmission path includes the telescopic movement of the rod and three rotations and four routes. The telescopic movement is mainly controlled by the actuator. When the rotation stiffness of the elastic hinge is not zero, the two paths of expansion and rotation are coupled. Only when the rotation stiffness is zero can decoupling be realized. Although the hinges seen so far have been elastically designed to reduce the Rotational stiffness but there is still a large gap

[0010] 4. The distance between the rotation centers of the elastic hinges on the upper platform is large, making it difficult to achieve decoupling

[0011] According to the decoupling design of the six-bar vibration isolation platform in the Stewart configuration, the six bars are divided into three groups, and the two bars in each group are perpendicular to each other and are connected to the same point as the upper platform through elastic hinges. Asana, the two poles in each group can be perpendicular to each other, but the common point connection with the upper platform cannot be achieved alone, and the entire six-pole platform cannot be decoupled

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