A Closed-Loop Method of Angular Rate for Improving Mems Gyroscope's Static and Linear Index

Abstract

The invention discloses an angular rate closed-loop method for improving the static and linearity indexes of a MEMS gyro, belonging to the sensor control field. The invention optimizes the control mode of an angular rate closed loop MEMS gyro, and adopts a fourth-order sigma-Delta feedforward sum circuit detects that modal displacement error signal detect by gyro, uses comb electrode to feedback control angular rate error information, parallel plate electrode to correct mechanical non-orthogonal error signal, angle rate error channel adopts direct-I type control, mechanical non-orthogonal error signal adopts direct-I type control, and mechanical non-orthogonal error signal adopts direct-I type control. Type II controller, so that the sensing mode of the MEMS gyro is always under the condition of zero rotational speed input, Finally, the closed-loop control is formed by superposing the closed-loop control signals, the MEMS gyroscope always keeps the balance position in the detection mode, and the MEMS gyroscope controlled by the servo system always works at a specific working point, so the static performance and dynamic performance of the MEMS gyroscope are improved.

Description

technical field [0001] The invention discloses an angular rate closed-loop method for improving the static and linearity indexes of MEMS gyroscopes, belonging to the technical field of sensor control. Background technique [0002] MEMS gyroscope is a new type of angular rate sensor. Its basic principle is based on the Coriolis force effect of mechanical resonance, which is essentially a kind of mechanical resonance gyroscope. High-precision MEMS gyroscopes have been successfully used in many occasions and environments, but the contradiction between static high precision and bandwidth of MEMS gyroscopes The problem is difficult to deal with, although the static performance of the MEMS gyroscope has reached the rate level (10-1000( ○ ) / h), but in terms of dynamic range, it is difficult to meet the requirements of bandwidth >70Hz (rate level), because high-precision MEMS gyroscopes often need to reduce the difference Δf between the driving and detection mode natural frequen...

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Problems solved by technology

Its basic principle is based on the Coriolis effect of mechanical resonance, which is essentially a kind of mechanical resonance gyroscope. High-precision MEMS gyroscopes have been successfully used in many occasions and environments, but the contradiction between static high precision and bandwidth of MEMS gyroscopes The problem is difficult to deal with, although the static performance of the MEMS gyroscope has reached the rate level (10-1000( ○ ) / h), but in terms of dynamic range, it is difficult to meet the requirements of bandwidth >70Hz (rate level), because high-precision MEMS gyroscopes often need to reduce the difference Δf between the driving and detection mode natural frequencies to obtain a higher High mechanical gain, and the mechanical bandwidth of the MEMS gyro open-loop detection direction is about half of Δf. Therefore, in order to obtain high mechanical gain, the high-precision MEMS gyroscope needs to sacrifice the bandwidth index of the MEMS gyroscope. The angular rate closed-loop is used in the detection mode. The method can effectively solve the contradiction between the static accuracy and bandwidth of the MEMS gyroscope

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