Small active vibration control system based on piezoelectric ceramic and piezoelectric accelerometer

Abstract

The invention discloses a small active vibration control system based on piezoelectric ceramic and a piezoelectric accelerometer, and relates to the technical field of precision machineries and modern control. The system comprises a micro-vibration source (00), a sensor (10), an acceleration module (20), a displacement module (30), a speed module (40), a first summator (50), an amplifying and filtering module (60), a second summator (70), a driving module (80) and the piezoelectric ceramic. The small active vibration control system has the advantages of simple structure, small size and easiness in integration, and can obtain a wider control band width, wherein the control frequency can achieve 200 Hz or even higher; the electric damping is adopted to replace mechanical damping, so that the realization is simpler; and a displacement signal is adopted as low-frequency drift compensation instead of adopting a method of direct current feedback to execute direct current stability, so that enough low-frequency gain and phase margin are guaranteed, and the control band width and the suppression ratio are effectively improved.

Description

technical field [0001] The present invention relates to the field of precision machinery and modern control technology, in particular to a small active vibration control system based on piezoelectric ceramics and piezoelectric accelerometers; the system is a simple structure, small size, practical and expandable The one-dimensional active vibration isolation system can be widely used in vibration-sensitive systems such as atomic force microscopy (AFM), laser interferometry, and gravitational wave detection. Background technique [0002] With the wide application of precision measurement, high-resolution observation and laser technology, good vibration isolation technology and vibration isolation platform are urgently needed. In many precision measurement experiments such as high-precision optics, laser frequency stabilization, laser interference gravitational wave detection, etc., ground vibration or even micro-vibration caused by sound or airflow, even at 10 -5 Below g, it...

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Problems solved by technology

[0005] If piezoelectric ceramics are used for vibration control, there are also the following two difficulties: First, although piezoelectric ceramics have good high-frequency characteristics, their resonance and the resonance of the mechanical structure will produce a large phase shift, which seriously affects the stability of the system. Secondly, because the piezoelectric ceramic is a kind of displacement generating device, the acceleration generated by it decreases sharply with the decrease of the frequency (12dB / oct), resulting in a small low-frequency gain, which needs to be compensated by a large circuit gain, which directly The DC drift of the circuit part is serious or even saturated, and the system cannot work

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