A dual-channel quadrature phase-shift demodulation filtering mems gyroscope interference suppression method

Abstract

The invention relates to a dual-path quadrature phase-shifting demodulation filter MEMS gyroscope interference suppression method, which belongs to the technical field of MEMS gyroscopes and anti-interference. The method includes: the displacement sensing signal is amplified by an amplifier, multiplied by the demodulated signals of the I-way and the Q-way respectively, and then low-pass filtered; judging whether the signal after the low-pass filtering of the Q-way contains an AC component, if not, then Output the signal after the low-pass filtering of the I channel as the angular velocity signal, otherwise the alarm prompts and perform Hilbert transformation on the signal after the low-pass filtering of the Q channel; the signal after the low-pass filtering of the I channel and the Hilbert transform of the Q channel The signals are added and subtracted respectively, and a section of the signal with the same time axis in the added and subtracted signals is intercepted, the energy of the two sections of the signal is calculated, and the section of the signal with the smaller energy is selected as the angular velocity signal. The method can filter out the displacement interference signal acting on the sensing direction and the frequency is not equal to the driving frequency, simplifies the structure and volume of the gyroscope, and also reduces the manufacturing cost.

Description

technical field [0001] The invention specifically relates to a MEMS gyroscope interference suppression method for dual-channel quadrature phase-shifting demodulation filtering, and belongs to the technical field of MEMS gyroscopes and anti-interference. Background technique [0002] MEMS gyroscopes for measuring angular velocity and angular acceleration have developed rapidly in recent years due to their advantages of small size, light weight, low power consumption, low cost, and easy integration, and are widely used in aerospace, automotive industry, smart Electronic equipment and other fields. However, the MEMS gyroscope adopts a spring-mass block-damping structure, which is easily disturbed by sound waves and vibrations near the resonance frequency, causing the gyroscope to output wrong angular velocity signals. The control system that calls the gyroscope data generally does not verify the accuracy of the sensing data, which will make the control system equipped with the...

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Problems solved by technology

[0006] The purpose of the present invention is to overcome the technical defects that the protection effect of the existing MEMS gyroscope acoustic protection method cannot cover the entire sound wave frequency band, the protection effect to common mode noise is relatively ideal, and the protection effect to non-common mode interference is relatively poor. An interference suppression method for dual-channel quadrature phase-shifting demodulation filtering. The displacement sensing signal relied on by the method is divided into I and Q two-channel signals after passing through an amplifier. Compared with the single-channel demodulation and filtering method, the Q channel is increased. Demodulation and phase-shifting circuit, that is, adding a Q-channel demodulation filter on the basis of the original single-channel demodulation and filtering method of the MEMS gyroscope, which can filter out displacement interference signals with different frequencies in the sensing direction and driving frequencies

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