CN102798386A - Three-degree-of-freedom resonance silicon micromechanical gyroscope - Google Patents

Abstract

The invention discloses a three-degree-of-freedom resonance silicon micromechanical gyroscope. The gyroscope comprises a glass substrate, an outer framework, a first-stage induction vibration framework, a second-stage induction vibration mass block, elastic beams, fixed comb teeth, sensitive comb-type electrodes, folding beams and anchoring points, consists of an upper layer and a lower layer, and is characterized in that the outer framework is fixed on the anchoring points through the elastic beams; the anchoring points are arranged on the glass substrate on the lower layer; two groups of straight comb-type electrostatic resonators are arranged on two sides of the outer framework; the second-stage induction vibration mass block is connected with the first-stage induction vibration framework by the folding beams; the first-stage induction vibration framework is arranged on the outer framework through the elastic beams; and two groups of linear sensitive comb-type electrodes are arranged on two sides of each of the first-stage induction vibration framework and the second-stage induction vibration mass block. The three-degree-of-freedom resonance silicon micromechanical gyroscope has the advantages that by a single-degree-of-freedom driving mode and two-degree-of-freedom detection mode, the anti-interference capacity of the micromechanical gyroscope is improved; and the micromechanical gyroscope is high in tolerance capacity, simple in structure and easy to machine.

Description

Three Degree Of Freedom micro-mechanical gyroscope of resonance silicon appearance

Technical field

The present invention relates to microelectromechanical systems and micro-inertia measuring technology, particularly a kind of Three Degree Of Freedom micro-mechanical gyroscope of resonance silicon appearance.

Background technology

The micro-mechanical inertia instrument comprises micro-mechanical gyroscope (MMG) and micro-mechanical accelerometer.Utilize microelectronic processing technology to allow micro mechanical structure and required electronic circuit are completely integrated on the silicon chip, thereby reach the high unity of performance, price, volume, weight, reliability aspects.Thereby this type instrument has a series of advantage (, low price little, in light weight like volume, reliability high, can produce in enormous quantities etc.), is with a wide range of applications.Be mainly used in auto industry, industrial monitoring and consumer product and Robotics, like air bag, anti-lock braking system, yaw rate sensor, tumble rate sensor, image stabilization and toy or the like; In military domain, can be used for agile bomb, can only shell, the independent navigation guidance system of tactical missile, new concept weapon and miniplane.

1993, a kind of novel micromechanical gyro---tuning-fork type line oscillation gyro was passed through in glass surface covering silicon layer fabrication techniques in U.S. De Leipo laboratory.This gyroscope is made up of double quality blocks, brace summer and crossbeam, and gyroscope adopts the line vibratory drive, and angular oscillation is responsive to be detected, and can detect the axial input angle speed on gyroscope plane.This gyrostatic double quality blocks design can increase the output signal, but its driving and responsive motion coupling fully, and the linearity of angular oscillation is relatively poor, has limited the raising of its sensitivity.

Summary of the invention

The objective of the invention is provides a kind of Three Degree Of Freedom micro-mechanical gyroscope of resonance silicon appearance to the defective that exists in the prior art.Three Degree Of Freedom micro-mechanical gyroscope of resonance silicon appearance is the surveying instrument that is used for perpendicular to pedestal level; Gyroscope is driven by single-degree-of-freedom; Two structures that degree of freedom detects; The present invention includes: glass substrate, straight shape pectination static resonator, outside framework 3, one-level induction vibration framework 4, secondary induction vibration mass 5, elastic beam 2a, 2b, 2c, 2d, fixed fingers 6a, 6b, responsive comb electrode 7a, 7b, 8a, 8b, folded beam 9a, 9b, anchor point 1a, 1b, 1c, 1d; Gyroscope is by two-layer composition up and down; It is characterized in that outside framework 3 is fixed on anchor point 1a, 1b, 1c, the 1d through elastic beam 2a, 2b, 2c, 2d, anchor point 1a, 1b, 1c, 1d are installed on the glass substrate of lower floor, and upper strata physical construction part is unsettled on the glass substrate part of lower floor; The both sides of outside framework 3 are provided with two groups of straight shape pectination static resonators; Secondary induction vibration mass 5 links to each other with one-level induction vibration framework 4 through folded beam 9a, 9b, and one-level induction vibration framework 4 is installed on the outside framework 3 through elastic beam 10a, 10b, 10c, 10d, and the both sides of one-level induction vibration framework 4 and secondary induction vibration mass 5 respectively are provided with the responsive comb electrode of two groups of linears.

Principle of work of the present invention:

Referring to Fig. 2, on broach shape static resonator, apply the opposite alternating voltage of phase place that contains current offset voltage, because the electrostatic attraction effect of alternation is that whole gyroscope bascule is sternly done the line vibration along driving axial.If the line vibrational waveform is sinusoidal wave, amplitude is A ₀, angular frequency is ω _n, then the line vibration displacement is:

x＝A ₀sinω _nt

So the linear velocity of vibration is:

V＝x&＝A ₀ω _ncosω _nt

If gyroscope has the input angular velocity ω around Z-direction _xThe time, because coriolis effect, the induction mass can receive the effect perpendicular to the Coriolis acceleration of the line direction of vibration of beginning, its size is:

Wherein V is the line vibration velocity along driving axial, and

is dextrorotation angle between input angular velocity and the line vibration velocity.

If the quality of two induction masses is respectively m ₁And m ₂, the coriolis force that acts on two masses is respectively:

If Coriolis acceleration a ₀Amplitude be a _C0So,

F ₁＝m ₁a _c＝m ₁a _c0cosω _nt，

F ₂＝m ₂a _c＝m ₂a _c0cosω _nt

The vibrational system of two masses can be listed kinetics equation shown in (Fig. 2):

$M\stackrel{\·\·}{x}+\mathrm{Kx}=F\sin {\mathrm{\ω}}_{n}t$

Wherein

$M=\left(\begin{array}{cc}{m}_1& 0\\ 0& m_2\end{array}\right),$ $K=\left(\begin{array}{cc}{k}_1+k_2& -k_2\\ -k_2& k_2\end{array}\right),$ $x=\left(\begin{array}{c}{x}_1\\ x_2\end{array}\right),$ $F=\left(\begin{array}{c}{m}_1{a}_{c0}\\ {\mathrm{<figure-callout\; id="2a"\; label="m"\; filenames="HDA0000063599590000011.png"\; state="\{\{state\}\}">m</figure-callout>}}_2{a}_{c0}\end{array}\right)$

Make x=Xsin ω _nT, X=(X ₁X ₂) ^TSo, have

$(K-{\mathrm{\&omega;}}_n^{2}M)X=F$

Find the solution and to get the complex frequency response matrix

$H={(K-{\mathrm{\&omega;}}_n^{2}M)}^{-1}=\frac{1}{\mathrm{\&Delta;}\left({\mathrm{\&omega;}}_n^2\right)}\left(\begin{array}{cc}{k}_2-{\mathrm{\&omega;}}_n^2{m}_2& k_2\\ k_2& k_1+k_2-{\mathrm{\&omega;}}_n^2{m}_1\end{array}\right)$

Wherein

$\mathrm{\&Delta;}\left({\mathrm{\&omega;}}_n^2\right)=|K-{\mathrm{\&omega;}}_n^{2}M|$

Can obtain the amplitude of this vibrational system

It is thus clear that the amplitude of two oscillators all is directly proportional with input angular velocity.Like this, the gap between detection comb and fixed test broach is changed by certain simple harmonic oscillation rule.These changes cause the capacitance variations between broach, can obtain the size perpendicular to the input angular velocity of in-plane through processing of circuit.

Because this gyroscope adopts two oscillator detection architecture, the coriolis force that is produced by input angular velocity makes it produce resonance, thereby higher tolerance degree is arranged.Secondly, adopt the broach differential capacitor to detect, realized responsive output decoupling, improved frequency stability and precision.

Advantage of the present invention provides a kind of detection mode of utilizing single-degree-of-freedom to drive mode, two degree of freedom and improves the micro-mechanical gyroscope of antijamming capability, and this micro-mechanical gyroscope tolerance ability is strong, simple in structure, be easy to processing.

Description of drawings

Fig. 1 is a upper strata of the present invention physical construction synoptic diagram;

Fig. 2 is the resonance synoptic diagram of detection quality of the present invention.

Among the figure: 1a anchor point, 1b anchor point, 1c anchor point, 1d anchor point, elastic beam 2a elastic beam, 2b elastic beam, 2c elastic beam, 2d elastic beam, 3 outside frameworks, 4 one-level induction vibration frameworks, 5 secondary induction vibration masses, 6a fixed fingers, 6b fixed fingers, the responsive comb electrode of 7a, the responsive comb electrode of 7b, the responsive comb electrode of 8a, the responsive comb electrode of 8b, 9a folded beam, 9b folded beam, 10a elastic beam, 10b elastic beam, 10c elastic beam, 10d elastic beam.

Embodiment

Further specify embodiments of the invention below in conjunction with accompanying drawing.

Referring to Fig. 1, present embodiment is made up of two-layer up and down, and the upper strata is the gyroscope physical construction that is produced on the monocrystalline silicon piece, is made up of three parts:

First is an outside framework 3; Be fixed on anchor point 1a, 1b, 1c, the 1d through four elastic beam 2a, 2b, 2c, 2d; Anchor point 1a, 1b, 1c, 1d are installed on the glass substrate of lower floor; Thereby make upper strata physical construction part unsettled on the glass substrate part of lower floor, shown in Figure 1 is that this gyroscope is produced on the upper strata physical construction on the monocrystalline silicon piece.

Second portion is an one-level induction vibration framework 4, is installed on the outside framework 3 by four elastic beam 10a, 10b, 10c, 10d, because the vibration that coriolis effect can produce the y direction.

Third part is a secondary induction vibration mass 5, is linked to each other with one-level induction vibration framework 4 by folded beam 9a, 9b.

The symmetria bilateralis of outside framework 3 is provided with two groups of straight shape pectination static resonators, and each static resonator is made up of inserting structure the movable broach on fixed fingers 6a, 6b and the outside framework 3, and straight shape pectination static resonator produces the vibration of directions X.One-level induction vibration framework 4 symmetria bilateralis are provided with the responsive comb electrode 7a of two groups of linear patterns, 7b, and the responsive comb electrode of each linear pattern is made up of fixed fingers electrode and activity comb electrodes interdigitation, can detect the vibration of y direction.Secondary induction vibration mass 5 both sides also are arranged with the responsive comb electrode 8a of two groups of linear patterns, 8b, and the responsive comb electrode of each linear pattern is made up of fixed fingers electrode and activity comb electrodes interdigitation, is used to respond to the vibration detection of y direction.

Claims (2)

1. Three Degree Of Freedom micro-mechanical gyroscope of resonance silicon appearance; Comprise: glass substrate, straight shape pectination static resonator, outside framework (3), one-level induction vibration framework (4), secondary induction vibration mass (5), elastic beam (2a, 2b, 2c, 2d), fixed fingers (6a, 6b), responsive comb electrode (7a, 7b, 8a, 8b), folded beam (9a, 9b), anchor point (1a, 1b, 1c, 1d); Gyroscope is by two-layer composition up and down; It is characterized in that outside framework (3) is fixed on the anchor point (1a, 1b, 1c, 1d) through elastic beam (2a, 2b, 2c, 2d); Anchor point (1a, 1b, 1c, 1d) is installed on the glass substrate of lower floor; Upper strata physical construction part is unsettled on the glass substrate part of lower floor; The both sides of outside framework (3) are provided with two groups of straight shape pectination static resonators; Secondary induction vibration mass (5) links to each other with one-level induction vibration framework (4) through folded beam (9a, 9b), and one-level induction vibration framework (4) is installed on the outside framework (3) through elastic beam (10a, 10b, 10c, 10d), and the both sides of one-level induction vibration framework (4) and secondary induction vibration mass (5) respectively are provided with the responsive comb electrode of two groups of linears.

2. Three Degree Of Freedom micro-mechanical gyroscope of resonance silicon appearance according to claim 1; The both sides that it is characterized in that outside framework (3) are provided with two groups of straight shape pectination static resonators; Each static resonator be fixed fingers (6a, 6b) with outside framework (3) on movable broach to inserting structure; One-level induction vibration framework (4) both sides are provided with the responsive comb electrode (7a, 7b) of two groups of linear patterns; The responsive comb electrode of each linear pattern is made up of fixed fingers electrode and activity comb electrodes interdigitation; Secondary induction vibration mass (5) both sides also are provided with the responsive comb electrode (8a, 8b) of two groups of linear patterns, and the responsive comb electrode of each linear pattern is made up of fixed fingers electrode and activity comb electrodes interdigitation.

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