Visual measuring device for vibration of piezoelectric flexible board structure and control method

Abstract

The invention discloses a visual measuring and control device for vibration of a piezoelectric flexible board structure. In order to detect the bending and twisting vibration of a flexible board, a charge coupled device (CCD) camera is arranged in front of the free end of the flexible board, an optical axis of the camera is ensured to be vertical to the free end surface in the static state, and in addition, a region of interest (ROI) of the free end edge is always in the camera view field range during the vibration. The CCD camera measures each frame of image of the edge vibration, a computer processes the detected image sequence, the free end surface edge is extracted, and the suggested algorithm is adopted for obtaining parameters for reflecting low-frequency bending and twisting vibration of the flexible board structure. Piezoelectric chips are symmetrically arranged at both sides of the flexible board to be used as drivers capable of obtaining the bending and twisting vibration of the flexible board in a mode of reasonably combining the piezoelectric sheets and exerting the voltage. The bending and twisting vibration signals measured in a visual are respectively fed back for controlling the vibration of the flexible board after being processed.

Description

technical field [0001] The invention relates to the measurement and active control of bending vibration and torsion angle of a large flexible cantilever structure, in particular to a visual measurement device and a control method for the vibration of a piezoelectric flexible plate structure. Background technique [0002] The solar panels of aerospace vehicles usually exist in the space environment in the form of large cantilever beam structures, and have the characteristics of low stiffness, small damping, low natural frequency and dense low-order modes. Due to the harsh space environment, the influence of cosmic wind and particle flow, and the maneuvering of the spacecraft itself, it is very easy to cause the continuous vibration of the solar panel structure of the spacecraft. If effective suppression measures are not adopted, its large-scale vibration will last for a long time, which will not only affect the working performance of the flexible structure itself, but also af...

AI Technical Summary

Problems solved by technology

However, the application of piezoelectric materials and shape memory alloys is limited due to factors such as their own strength, fatigue life, and temperature resistance; the signal measured by the acceleration sensor is relatively noisy, and the signal needs to be filtered

The above-mentioned sensors all adopt the contact measurement method. Since the sensor needs to be in direct contact with the flexible structure, some physical effects (such as changing the frequency and amplitude of the vibrating object, etc.) will be added to the flexible structure, which will affect the accuracy and objectivity of the measurement results.

[0005] Chinese patent application CN200810218738 discloses a vision-based space sailboard bending and torsion low-frequency mode detection method and device. The device installs an LED light-emitting tube on the longitudinal centerline of the free end of the flexible cantilever board, and installs it on the longitudinal centerline of the flexible cantilever board. Install another LED light-emitting tube on one side of the device, but it is difficult for this device to determine the appropriate threshold according to the specific conditions of the target image

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