All-forward capacitance type micro-machined gyroscope

Abstract

The invention discloses an all-forward capacitance type micro-machined gyroscope comprising a glass substrate (1), metal electrodes A(2), B(14), C(16), and D(19), forward pectinated drivers A(6) and B(7), a mass block (8), a forward pectinated differential capacitor (12), a driving detection capacitor (15), fixed electrodes A(5), B(17) and C(18), a driving frame (4), anchor points A(10) and B(13), and elastic beams A(3), B(9) and C(11). In the invention, a forward driving, driving detection and the pectinated difference capacitor structure are adopted to solve the problem that the capacitance variation quantity is nonlinear to displacement variation quantity, thereby improving the signal to noise ratio of the micro-machined gyroscope. A U-shaped decoupling beam structure satisfies a bipolar decoupling function. A driving system is limited to move in a driving direction X, and a detection system is limited to move in a detection direction Y.

Description

technical field [0001] The invention relates to an all-forward capacitive micro-mechanical gyroscope, which belongs to the field of micro-electro-mechanical systems and the field of inertial measurement. Background technique [0002] Compared with traditional gyroscopes, silicon micromechanical gyroscopes manufactured by micromechanical technology have the advantages of small size, light weight, low cost, low power consumption, high reliability, mass production, and easy integration with CMOS interface circuits. It can be widely used in many fields such as aviation, aerospace, automobiles, weapons, medicine, consumer electronics, etc., and has huge market potential. Nowadays, silicon micromachined gyroscopes with various structures emerge in endlessly in the world, and their common feature is that they have two vibration directions perpendicular to each other, that is, the exciting vibration direction and the sensitive vibration direction caused by Coriolis force. [0003] ...

AI Technical Summary

Problems solved by technology

The detection method of the micro-mechanical gyroscope generally adopts the differential capacitance detection of the variable-gap offset comb tooth, and detects the Coriolis force through the change of the distance between the comb-tooth electrodes, that is, the change of capacitance, and then detects the angular velocity signal. The advantage is that the structure is simple, but There is a large nonlinear relationship between the capacitance change and the plate displacement, that is, there is a serious nonlinear relationship between the detection output and the detected Coriolis force

In order to improve the linearity of the variable-gap bias comb differential capacitance, the gap difference can be increased, but this will reduce the mass of the detection mass and affect the sensitivity of the gyroscope

There is a large pressure-film damping between the bias comb-tooth differential capacitors, which makes the quality factor very low, which limits the improvement of the sensitivity of the micro-machined gyroscope. Generally, it needs to work in a vacuum state, which increases the difficulty and cost of packaging.

Since the variable-gap offset comb-tooth differential capacitor uses a variable-gap method to detect capacitance changes, the action stroke of close-range forces such as capillary adhesion force and van der Waals force will change accordingly, which will affect the stability and reliability of the micromechanical gyroscope.

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