Electromagnetically-driven grating accelerometer and closed-loop detection method

Abstract

The invention discloses an electromagnetically-driven grating accelerometer and a closed-loop detection method. The method comprises the steps of achieving the photoelectric conversion of a diffraction interference signal outputted by an accelerometer sensitive structure through a photoelectric detector, enabling the diffraction interference signal to enter a digital detection circuit after beingamplified and filtered through a pre-amplification filter circuit, and carrying out the analog-to-digital conversion through an A/D converter, performing phase-sensitive demodulation on a demodulationsignal generated by an FPGA module in a phase-sensitive detection module, and filtering noise and background stray light interference through a digital low-pass filter to obtain a purified closed-loop error signal, sending the purified closed-loop error signal to a controller for PID control adjustment to obtain a feedback signal, on one hand, enabling the feedback signal to serve as output, on the other hand, enabling the feedback signal and a modulation signal generated by the FPGA module to be converted through a D/A converter, and after signal amplification is conducted through a linear amplification circuit, loading the feedback signal on a magnetic torquer of a sensitive structure; phase modulation of a cantilever beam is carried out by changing the adsorption effect of a mass blockand a magnet, and servo balance is achieved.

Description

technical field [0001] The invention relates to the fields of inertial navigation and optical accelerometers, in particular to an electromagnetically driven grating accelerometer and a closed-loop detection method. Background technique [0002] The accelerometer is one of the key components of the inertial navigation system and is widely used in various fields of national production and life. Traditional accelerometers are capacitive effects, piezoresistive effects or tunneling electron effects. This sensing method has some inherent disadvantages, such as being easily affected by ambient temperature and cross-sensitivity by electromagnetic interference. Compared with the traditional accelerometer, the micron grating accelerometer belonging to MOMES has strong anti-electromagnetic interference ability, small size and high precision, better sensitivity and linearity, and has better prospects and application value. The linearity and detection accuracy of the accelerometer are ...

AI Technical Summary

Problems solved by technology

Theoretical dynamic detection range is no longer limited, but because the actual input-output relationship between the electrostatic voltage and the plate spacing conforms to the second-order nonlinear function, when a large acceleration is input, a larger feedback voltage is required, which may cause the plate to be damaged. Adsorption and Breakdown Effects

And the introduction of the second-order nonlinear link does not substantially improve the linearity, but the detection accuracy decreases.

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