Signal processing method capable of eliminating quadrature errors of micro-machined gyroscope

Abstract

The invention provides a signal processing method capable of eliminating quadrature errors of a micro-machined gyroscope. One path of a gyroscope driving signal becomes a first demodulation reference signal after passing through a phase shifter, the other path of the gyroscope driving signal becomes a second demodulation reference signal orthogonal with the first demodulation reference signal after passing through the same phase shifter and a 90-DEG phase shifter, the two demodulation reference signals respectively carry out secondary phase-sensitive demodulation on an input signal, and an obtained signal undergoes addition and subtraction after low pass filtering; an addition value signal is input into a differentiating circuit for feedback control of the phase value of the first demodulation reference signal, the phase of the first demodulation reference signal Vref1(t) lags behind an input angular velocity signal by 45 DEG when a control signal is zero, a pure quadrature error signal is output in addition value output, and quadrature errors are completely eliminated in subtraction value output. The method can effectively reduce influence of quadrature errors on useful angular velocity and substantially improve measurement accuracy of an electrostatically actuated capacitive micro-machined gyroscope.

Description

technical field [0001] The invention relates to a signal processing method capable of eliminating the quadrature error of a micro-mechanical gyroscope, in particular to an electrostatically driven capacitive micro-mechanical gyroscope. Background technique [0002] At present, there are still many deficiencies in the suppression of quadrature error of micromachined gyroscopes. A gyroscope is a sensor that can detect the attitude and state changes of a moving object even without an external reference signal. Its function is to sense the angular velocity of the moving object. In the early 1990s, with the rapid development of micro-machining technology, the third-generation micro-mechanical gyroscope based on MEMS technology was born. This gyroscope has the advantages of small size, light weight, wide bandwidth, low power consumption, and high impact resistance. , are widely used in military and civilian fields. The sensitive structure of the micromachined gyroscope is proces...

AI Technical Summary

Problems solved by technology

[0004] 1. When synchronous demodulation technology is used to eliminate quadrature error, it is difficult to realize that the phases of the reference signal and the signal to be demodulated are completely equal, and the actual signal will inevitably have a phase error due to transmission delay during processing. Therefore, the above two It is very difficult to realize that the signal phases are completely equal, which also leads to the fact that in practical applications, the quadrature error signal cannot be completely eliminated by the synchronous demodulation method. For the problem that the quadrature error caused by this situation cannot be completely eliminated, there is currently no corresponding s solution

[0005] 2. If electrostatic force feedback is used to form a closed-loop system to suppress quadrature error, the extraction of quadrature error is based on the fact that the phase difference between the reference signal and the signal to be demodulated is exactly 90°, and it is very difficult to meet this condition. How to extract the pure quadrature error signal or eliminate the phase error as much as possible is a technical difficulty, and there is no corresponding solution at present

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