31results about How to "Suppression of low frequency vibration" patented technology

The invention discloses a platform and a method of main and passive vibration isolation in space six-degree of freedom based on electromagnetic negative stiffness. The platform comprises a load platform, a foundation platform and six electromagnetic negative stiffness vibration isolators, wherein the six electromagnetic negative stiffness vibration isolators are fixed between the load platform andthe foundation platform through a connecting piece; the two adjacent vibration isolators are perpendicular to each other in the axial direction, and the load platform has six-degree of freedom relative to the foundation platform; each electromagnetic negative stiffness vibration isolator comprises an actuating rod, an upper shell, a lower shell, a combined disc spring, a base, a bottom supportingrod and two sets of excitation devices, wherein the actuating rod is fixedly connected with the upper shell through a cross beam spring piece, a strain sensor is pasted on the cross beam spring piece, and is used for detecting the axial displacement of the actuating rod; each vibration isolator can realize active control of equivalent electromagnetic negative rigidity, so that the vibration isolation platform is of a positive and negative stiffness parallel structure in six-degrees of freedom, the vibration isolators have relatively low resonance frequency and a very wide vibration isolationfrequency band, so that micro-vibrations in the space six-degree of freedom direction can be effectively inhibited. According to the platform and the method, the platform and the method of the main and passive vibration isolation in the space six-degree of freedom based on the electromagnetic negative stiffness are suitable for equipment micro-vibration main and passive vibration isolation in thefield of spaceflight aviation, precise instruments and the like.

The invention provides a shear type damping tube having a vibration damping performance and a vibration damping adapter. The shear type damping tube comprises an aluminum alloy joint, a carbon fiber tube, a damping glue layer, an aluminum alloy bushing and a steel spring tube, wherein the upper section of the carbon fiber tube is in bonding connection with the aluminum alloy joint; the outer side of the lower section of the carbon fiber tube is connected with the inner side of the aluminum alloy bushing through the damping glue layer; the inner side of the lower section of the carbon fiber tube is in bonding connection with the outer side of the steel spring tube; and the aluminum alloy bushing is connected with the steel spring tube. Compared with the prior art, the vibration damping adapter, produced by the shear type damping tube having the vibration damping performance, has excellent vibration damping performance to restrain low-frequency vibration of satellite effective load of an active flight section of a carrying rocket, and has better rigidity to improve the mechanical environment of the satellite effective load at the active flight section of the rocket when being used for connecting the carrier rocket with a satellite.

The invention discloses an integral metal spring type active vibration reduction table. The integral metal spring type active vibration reduction table comprises a bottom plate (10) and an upper panel (60). Passive vibration isolation units and active vibration isolation units are arranged at the four corners of the bottom plate (10) correspondingly. The passive vibration isolation units are used for achieving high-frequency attenuation of the vibration reduction table and each comprise a metal spring assembly, vibration isolation rubber (50) and a structural damper. The active vibration isolation units are used for achieving active control over the vibration reduction table and each comprise a feedback speed sensor, a feedforward speed sensor, a Lorentz motor and a controller. According to the vibration reduction table, the vibration reduction technique combining passive vibration isolation with active vibration reduction is adopted, high-frequency vibration can be isolated comprehensively, low-frequency vibration can be effectively restrained, and the transmission rate of low-frequency vibration is ensured; and meanwhile, high attenuation rate of high-frequency vibration is achieved, full decoupling under six-degree of freedom control can be achieved, and application is flexible.

The invention discloses a vibration suppression method utilizing the rotation of the root of a flexible component, which can quickly suppress the vibration of the flexible component without greatly increasing the complexity of the system. First, according to the mass parameters of the satellite and the modal analysis results of the flexible part, a dynamic model of the satellite with flexible rotating parts is established. Next, the root of the flexible component suppresses the flexural vibration through the rotation angular acceleration, and feeds back the rotation angle and angular velocity of the component itself, so as to avoid excessive rotation angle and angular velocity of the flexible component root. Finally, in the attitude control of the satellite body, the disturbance generated by the root motion of the flexible component is compensated to ensure the high-precision control of the satellite body. The method proposed by the invention can quickly suppress the low-order vibration of the flexible component, and at the same time, the rotational motion of the root of the flexible component converges, avoiding the impact on the orientation of the component. In addition, the additional disturbance caused by the rotation of the root of the flexible component is compensated to reduce the influence on the control of the satellite body.