CN101303234A

CN101303234A - Self-decoupling high-sensitivity resonance silicon micro mechanical gyroscope

Info

Publication number: CN101303234A
Application number: CNA2008101122937A
Authority: CN
Inventors: 樊尚春; 王路达; 郭占社
Original assignee: Beihang University
Current assignee: Beihang University; Beijing University of Aeronautics and Astronautics
Priority date: 2008-05-22
Filing date: 2008-05-22
Publication date: 2008-11-12

Abstract

A self-decoupling high-sensitivity resonant silicon micromechanical gyroscope mainly comprises an outer mass block, an inner mass block, a cantilever beam, a lever amplification mechanism, a DETF(double-ended tuning fork), a driving electrode, a detecting electrode, wherein the lever amplification mechanism, the fork, the driving electrode and the detecting electrode are arranged in the inner mass block. The structure of the micromechanical gyroscope is axially symmetric, and the inner and outer mass blocks are in Chinese character 'hui' shape, which is capable of making the component implement larger mass block in limited volume. The outer mass block and the inner mass block are separated by a folding beam for reducing effectively the coupling; a resonant beam is in the form of DETF, and both ends of the resonant beam are connected with the periphery through a fine neck structure, thereby reducing effectively the energy coupling of the resonant beam and the peripheral structure; two forks are arranged symmetrically for implementing difference output of resonant frequency, thereby reducing effectively the common-mode interference. The structural form of the invention improves sensitivity and resolution of the accelerometer, and reduces the coupling of the driving direction vibration to the detecting direction by using framework structure.

Description

A kind of self-decoupling high-sensitivity resonance silicon micro mechanical gyroscope

Technical field

The invention belongs to micro-electromechanical system field, be a kind of novel micromechanical gyro.

Background technology

MEMS (micro electro mechanical system) (Microelectromechanical System, being called for short MEMS) the MEMS sensor that maturation makes that development cost is low, in light weight, volume is little and low in energy consumption that is tending towards gradually of the development of technology and process technology thereof becomes possibility, also becomes the trend of following sensor research simultaneously.

Gyro is the sensor that angular velocity is tested of field widespread uses such as a kind of Aeronautics and Astronautics.Especially Aero-Space etc. are to device quality and all very strict field of volume requirement in a lot of fields, and development MEMS angular-rate sensor has become inevitable.In the MEMS of numerous kinds gyro, the resonant micromechanical silicon angular-rate sensor is owing to having accurate numeral output, being subjected to that external interference is low, the measuring accuracy advantages of higher becomes domestic and international research focus.At present, external existing many scientific research institutions are carrying out correlative study, most typical exemplar is exactly the Seshia A A of University of California Berkeley of the U.S., Howe R T, Montague S.An Integrated Microelectromechanical Resonant Output Gyroscope[J] .15thIEEE Micro Electro Mechanical Systems Conference, 2002. (1): the DETF that utilizes static excitation, capacitor vibration pick-up of 20-24. development is at the silicon resonance type gyro of mass outside.Though above-mentioned this kind sensor has been realized input at present, the problem of its existence is exactly that precision is lower, and the technological requirement height, according to the present MEMS processing technology level of China, is difficult to process similar sensor.In addition, retrieves the related application name and be called " a kind of resonant-type micro-mechanical optic fiber gyroscope ", application number 200610012216.5, but the structure of application also is a lumped mass that excitation and pick-up are all in the mass outside, and be unfavorable to improving sensitivity.Structure of the present invention has adopted inside and outside double quality blocks structure, and the DETF pick-up partly is arranged on mass inside, helps improving from structure the measuring accuracy of sensor.

Summary of the invention

Purpose of the present invention: overcome the deficiencies in the prior art, provide a kind of decoupling zero, strong interference immunity, measuring accuracy high and resonant-type micro-mechanical optic fiber gyroscope cheaply.

Technical solution of the present invention: a kind of self-decoupling high-sensitivity resonance silicon micro mechanical gyroscope mainly comprises: the lever enlarger of outer mass, interior mass, semi-girder, two symmetries, the tuning fork DETF of two symmetries, drive electrode, detecting electrode; Total is the double quality blocks structure of zhou duicheng tuxing, and inside and outside mass is " returning " font, and both connect by the folded beam symmetry, but the implementation structure decoupling zero; Outer quality supports by semi-girder; The lever enlarger of two symmetries, tuning fork DETF, drive electrode and the detecting electrode of two symmetries are positioned in the mass, connect by middle anchor point between one end of two tuning forks, the other end of two tuning forks is connected with interior mass by the lever enlarger, and in each tuning fork both sides broach is arranged, constitute drive electrode and detecting electrode.

Have thin neck structure to be connected with anchor point in the described lever enlarger, described thin neck structure is 2 to 10 microns.

The two ends of described each tuning fork are connected with the lever enlarger by the anchor point of thin neck structure with the centre respectively, and described thin neck structure is 2 to 10 microns.

The tuning fork structure parameter of described two symmetries is identical.

The principle of the present invention and the course of work are: outer mass drives by broach, and is reciprocating at driving direction.When gyro was subjected to adding angular velocity, outer mass produced coriolis force simultaneously, and coriolis force imports interior mass into by folded beam, then by the leverage amplification in tuning fork DETF one end.By the differential output of two DETF, can make output quantity double a DETF.Therefore, by the sinusoidal output frequency of demodulation, can obtain the angular velocity of extraneous input.

The present invention's advantage compared with prior art is:

(1) the inside and outside mass block structure of utilization, and inside and outside quality separates with folded beam, effectively reduces coupling, thereby has realized structure decoupling.

(2) sound is placed in the interior mass, make it improve sensitivity effectively realizing long length in the area.

(3) structure is a zhou duicheng tuxing, and mass shows " returning " type, has increased quality in limited area, has improved sensitivity.

(4) there is thin neck structure (2 to 10 microns) to be connected in the lever enlarger, effectively reduced the anchor point energy consumption with anchor point.

(5) the DETF two ends are connected by thin neck structure (2 to 10 microns) and anchor point and lever, have reduced the coupling of DETF and peripheral structure ground energy effectively.

(6) utilize two DETF to realize variate, reduced common mode interference effectively, and realized the differential output of resonance frequency effectively.

(7) static driven of broach offset, capacitive detecting structure can be realized higher drive strength and detection sensitivity, have good processing compatibility simultaneously.

(8) the present invention since output be that frequency signal needn't just can be easily and computer interface through A/D conversion, so its measuring accuracy has also obtained improving greatly.

(9) because the present invention utilizes existing MEMS technology to make, make the mass production of device become possibility, also reduced its cost of manufacture simultaneously.

Version of the present invention improved sensitivity, the resolution of accelerometer, and the utilization framed structure reduced the driving direction vibration to the detection side to coupling.

Description of drawings

Fig. 1 is a structural representation of the present invention.

Embodiment

As shown in Figure 1, silicon micromechanical gyroscope of the present invention comprises: 15,16 outer interior masses; 2, the semi-girder of the outer quality of 8,22,28 symmetric support; 1,9,21,29 is the anchor point of semi-girder; 6,24 are the driving comb of outer quality (comprising movable comb and fixed fingers); 3,4,5,7,23,25,26,27 is the folded beam of the inside and outside quality of connection of symmetry; 37,10 is the lever structure for amplifying of symmetry; For reducing the energy consumption of anchor point, lever enlarger 37 is connected with anchor point 34 by thin neck structure (2 to 10 microns) 32,35, and while lever enlarger 10 passes through thin neck structure (2 to 10 microns) 12,14 and is connected with anchor point 13; DETF36 is connected with leverage 37 with anchor point 19 respectively by thin neck structure (2 to 10 microns) 30,31, be connected with leverage 10 with anchor point 19 respectively by thin neck structure (2 to 10 microns) 18,17 with the DETF11 of DETF 36 symmetries, this kind form can be eliminated tuning fork and extraneous vibration coupling effectively, and realizes the differential output of resonance frequency; And in DETF36,11 both sides driving and detection comb 20,33 (comprising movable comb and fixed fingers) are arranged, realized static driven, capacitance detecting.

The course of work of the present invention: outer mass 15 is done the to-and-fro movement of y direction under the driving of broach 24,6.When the input of z direction of principal axis angular velocity, the coriolis force that outer mass 15 produces along the x direction.Be passed to interior mass 16 by folded

beam

3,4,5,7,23,25,26,27 coriolis forces, coriolis force is applied to the axial of

tuning fork

36 and 11 through the amplification of

lever enlarger

37 and 10, makes

tuning fork

36 and 11 bear pulling force and pressure respectively.The tuning fork resonance frequency of tension increases, the tuning fork resonance frequency of pressurized reduces, the difference that detects two resonance frequencies utilizes the driving of

tuning fork

36 and 11 both sides and

detection comb

20,33 to realize static exciting and capacitor vibration pick-up as output, is changed to calculate measured angle speed by the resonance frequency that records.

In sum, the present invention proposes a kind of self-decoupling high-sensitivity resonance silicon micro mechanical gyroscope, but the application of this class angular-rate sensor in the high precision field opened up in little, the in light weight implementation structure decoupling zero of its volume, highly sensitive angular velocity measurement.

Claims

1, a kind of self-decoupling high-sensitivity resonance silicon micro mechanical gyroscope is characterized in that: mainly comprise: the lever enlarger of outer mass, interior mass, semi-girder, two symmetries, the tuning fork DETF of two symmetries, drive electrode, detecting electrode; Total is the double quality blocks structure of zhou duicheng tuxing, and inside and outside mass is " returning " font, and both connect by the folded beam symmetry, but the implementation structure decoupling zero; Outer quality supports by semi-girder; The lever enlarger of two symmetries, tuning fork DETF, drive electrode and the detecting electrode of two symmetries are positioned in the mass, connect by middle anchor point between one end of two tuning forks, the other end of two tuning forks is connected with interior mass by the lever enlarger, and in each tuning fork both sides broach is arranged, constitute drive electrode and detecting electrode.

2, a kind of self-decoupling high-sensitivity resonance silicon micro mechanical gyroscope according to claim 1 is characterized in that: have thin neck structure to be connected with anchor point in the described lever enlarger, described thin neck structure is 2 to 10 microns.

3, a kind of self-decoupling high-sensitivity resonance silicon micro mechanical gyroscope according to claim 1, it is characterized in that: the two ends of described each tuning fork are connected with the lever enlarger by the anchor point of thin neck structure with the centre respectively, and described thin neck structure is 2 to 10 microns.

4, a kind of self-decoupling high-sensitivity resonance silicon micro mechanical gyroscope according to claim 1 is characterized in that: the tuning fork structure parameter of described two symmetries is identical.