CN201352121Y

CN201352121Y - Vibratory micromachined gyroscope

Info

Publication number: CN201352121Y
Application number: CNU2008201243848U
Authority: CN
Inventors: 高宏; 王庆; 齐晓红
Original assignee: UNIS CO Ltd
Current assignee: UNIS CO Ltd; Unisplendour Corp Ltd
Priority date: 2008-12-12
Filing date: 2008-12-12
Publication date: 2009-11-25
Anticipated expiration: 2018-12-12

Abstract

The utility model relates to a vibratory micromachined gyroscope, belonging to the technical field of an inertial sensor in a micro-electromechanical system. A driving mass block is fixed on the anchor point of the glass substrate of the micromachined gyroscope, and a detecting mass block and an isolation mass block are positioned in the driving mass block; the detecting mass block is fixed on the anchor point of the glass substrate of the micromachined gyroscope, and the isolation mass block as well as the driving mass block and the detecting mass block are oppositely fixed; detecting capacitance fixed electrodes and detecting capacitance movable electrodes are positioned in the detecting mass block, and the detecting capacitance fixed electrodes are fixed on the glass substrate of the micromachined gyroscope; the detecting capacitance movable electrodes and the detecting mass block are oppositely fixed, and driving capacitance movable electrodes and the driving mass block are oppositely fixed; and driving capacitance fixed electrodes are fixed on the glass substrate of the micromachined gyroscope. The micromachined gyroscope has the advantages of no mechanical coupling problems, complete elimination of the detection interference brought by mechanical coupling, improvement on the sensitivity of themechanical gyroscope, and easy mass production.

Description

A kind of vibrating micromechanical gyro

Technical field

The utility model relates to a kind of vibrating micromechanical gyro, belong to the inertial sensor technical field in the MEMS (micro electro mechanical system), be particularly related to a kind of oscillatory type decoupling micromechanical gyroscope, the motion state that can be widely used in automotive electronics, Aero-Space, weaponry is measured and control.

Background technology

The coriolis force that gyro mainly utilizes Coriolis effect to produce is measured the angular motion parameter in moving object relative inertness space, can be widely used in measurement and control to object moving state in the product for civilian use and defence product field.Traditional gyro is subjected to the restriction of factors such as volume, weight, power consumption and cost, is difficult to apply at civil area.With integrated circuit (IC) technology and precision optical machinery processing technology serves as that micromechanical gyro that the basis makes has that volume is little, in light weight, cost is low, the high outstanding advantage of reliability, thereby can be used for civil applications field widely such as motion state of automobile control system, camera stabilization system, movable machinery control, robot observing and controlling, geodetic surveying, medical apparatus.

The vibrating micromechanical gyro basic structure of acquisition widespread use at present as shown in Figure 1.The fixed electorde 7 of the driving mass 3 of whole micromechanical gyro, the fixed electorde 4 that detects mass 8, driving electric capacity and detection electric capacity etc. is to carry out etching to obtain on same silicon chip.Driving mass 3 is fixed on the anchor point 9 of glass substrate by driving elastic beam 1.Driving the fixed electorde 4 of electric capacity and the fixed electorde 7 of detection electric capacity also is fixed on the glass substrate.The x direction is the transverse drive shaft of micromechanical gyro, and the y direction is vertical sensitive axes.On the fixed electorde 4 that drives electric capacity, apply periodically variable voltage, can make micromechanical gyro drive mass 3 and on driving direction, produce periodically variable static driven power, make to drive mass 3 and detect the vibration that mass 8 produces the x direction.Fail man-hour when the z direction has sensitive angular, because the effect of coriolis force detects mass 8 and produces vibration along the y direction, the size of amplitude and static driven power and z deflection velocity magnitude are linear.Along with the vibration that detects mass 8, detecting the movable electrode of electric capacity and the spacing between the fixed electorde changes immediately, output differential capacitor amount is changed, can realize the detection of the size of Oscillation Amplitude can obtaining the z axis angular rate by post processing electric circuit by the variation that detects the differential capacitor amount.

Above-mentioned vibrating micromechanical gyro exists the mechanical couplings problem between serious driving mode and the detection mode when working, restricting the further raising of micromechanical gyro performance.Micromechanical gyro shown in Figure 1 is when being subjected to x direction electrostatic forcing, driving mass 3 drive detection masses 8 vibrates along the x direction of principal axis simultaneously, the relative area that detects electric capacity movable electrode and fixed electorde is changed, the differential capacitor amount that causes detecting electric capacity also changes thereupon, thereby bring serious disturbance for the detection of y direction vibration signal, reduce the performance of vibrating micromechanical gyro, be difficult for realizing high-precision angular velocity measurement.

Summary of the invention

The purpose of this utility model is to propose a kind of vibrating micromechanical gyro, with the mechanical couplings that overcomes existing vibrating micromechanical gyro (vibration of driving direction can cause the detection side to vibration) problem, make the driving mode of oscillation independent fully with the detection mode of oscillation, can eliminate the mechanical couplings problem that drives between mode and the detection mode, suppress the parasitic disturbances that the vibration of driving direction brings to detection signal effectively, improve the performance of vibrating micromechanical gyro.

The vibrating micromechanical gyro that the utility model proposes comprises driving mass, detect mass, isolate mass, drive the capacitor fixing electrode, drive the electric capacity movable electrode, detect the capacitor fixing electrode and detecting the electric capacity movable electrode; Described driving mass is fixed on the anchor point of micromechanical gyro glass substrate by driving elastic beam; Described detection mass and isolation mass are positioned at and drive mass, detecting mass is fixed on the anchor point of micromechanical gyro glass substrate by detecting elastic beam, described isolation mass is isolated elastic supporting beams and is driven the mass relative fixed by the y direction, and isolates elastic supporting beams and detect the mass relative fixed by the x direction; Detect the capacitor fixing electrode and be positioned at the detection mass with detection electric capacity movable electrode, the fixed electorde that detects electric capacity is fixed on the micromechanical gyro glass substrate, detects the movable electrode and the detection mass relative fixed of electric capacity; Described driving electric capacity movable electrode and driving mass relative fixed, the fixed electorde that drives electric capacity is fixed on the micromechanical gyro glass substrate.

The vibrating micromechanical gyro that the utility model proposes, its advantage is:

(1) the detection mass on the existing vibrating micromechanical gyro has the degree of freedom of x and y both direction, therefore just has the mechanical couplings problem on structural design.Detection mass of the present utility model has only the degree of freedom of a direction of y axle, and with the x direction quadrature that drives mass, therefore do not have the mechanical couplings problem in design.

(2) vibrating micromechanical gyro of the present utility model, increased isolation mass block structure with two-freedom, but the mechanical couplings between isolation drive mass and the detection mass, it is independent fully with the motion that detects mode of oscillation to guarantee to drive mode of oscillation, on structural design, eliminate the detection interference that mechanical couplings is brought fully, improved micromechanical gyro sensitivity.

(3) identical with the processing of traditional micromechanical gyro, do not increase technology difficulty and processing cost, be easy to produce in batches.

Description of drawings

Fig. 1 is existing conventional vibrating micromechanical gyro planar structure synoptic diagram.

Fig. 2 is the planar structure synoptic diagram of the utility model vibrating micromechanical gyro.

Among Fig. 1 and Fig. 2, the 1st, drive elastic beam, the 2nd, detect elastic beam, the 3rd, drive mass, the 4th, drive the capacitor fixing electrode, the 5th, the movable electrode of driving electric capacity, the 6th, the movable electrode of detection electric capacity, the 7th, detect the capacitor fixing electrode, the 8th, detect mass, the 9th, drive the elastic beam anchor point, the 10th, isolate mass, the 11st, detect the elastic beam anchor point, the 12nd, the x direction is isolated elastic supporting beams, and the 13rd, the y direction is isolated elastic supporting beams.

Embodiment

The vibrating micromechanical gyro that the utility model proposes, its plane structure chart comprises driving mass 3, detect mass 8, isolate mass 10, drive capacitor fixing electrode 4, drive electric capacity movable electrode 5, detect capacitor fixing electrode 6 and detecting electric capacity movable electrode 7 as shown in Figure 2.Driving mass 3 is fixed on the anchor point 9 of micromechanical gyro glass substrate by driving elastic beam 1.Detect mass 8 and be positioned at driving mass 3, detect mass 8 and be fixed on the anchor point 11 of micromechanical gyro glass substrate by detecting elastic beam 2 with isolation mass 10.Isolate mass 10 and isolate elastic supporting beams 13 and drive mass 3 relative fixed, and isolate elastic supporting beams 12 and detect mass 2 relative fixed by the x direction by the y direction.Detect capacitor fixing electrode 7 and be positioned at detection mass 8 with detection electric capacity movable electrode 6, the fixed electorde 7 that detects electric capacity is fixed on the micromechanical gyro glass substrate, detects the movable electrode 6 and detection mass 8 relative fixed of electric capacity.Drive electric capacity movable electrode 5 and drive mass 3 relative fixed, the fixed electorde 4 that drives electric capacity is fixed on the micromechanical gyro glass substrate.

Below in conjunction with accompanying drawing, introduce the principle of work of the utility model vibrating micromechanical gyro in detail:

When structural design, the elastic supporting beams that drives mass is very low along the axial equivalent stiffness of x, and the axial equivalent stiffness of y is very big, can only do the axial motion of x; The elastic supporting beams that detects mass is very low along the axial equivalent stiffness of y, and the axial equivalent stiffness of x is very big, is fixed on glass substrate owing to detect the mass elastic supporting beams, can only do the axial motion of y; It is all very low along the axial equivalent stiffness of x, y to isolate the mass elastic supporting beams, can participate in the motion of x and y both direction.

Isolate mass and vibrate simultaneously when driving mass when the x direction of principal axis vibrate, driving,, so detect mass and do not produce motion because it is very big along the axial equivalent stiffness of x to detect the elastic supporting beams of mass along the x axle.When the angular velocity input is arranged at the z direction of principal axis, isolate mass and be subjected to axial coriolis force effect along y, force and isolate mass drive detection mass along y direction of principal axis up-down vibration, its amplitude is directly proportional with the input angular velocity size.

Micromechanical gyro of the present utility model drives mass and only moves in x axle (driving) direction, detecting mass only moves in y axle (driving) direction, have only and isolate the motion that mass participates in x axle and y axle both direction, therefore it is independent fully with the detection mode of oscillation to drive mode of oscillation, has eliminated the motion of driving direction fully the detection side is disturbed to the mechanical couplings of motion.

With reference to Fig. 2, the utility model comprises that driving mass 3, isolation mass 10, detection mass 8, driving mass elastic supporting beams 1, detection mass elastic supporting beams 2, x and y direction isolates parts such as elastic supporting

beams

12,13, driving capacitor fixing electrode 4, driving electric capacity movable electrode 5, detection capacitor fixing electrode 7, detection electric capacity movable electrode 6, except that driving capacitor fixing electrode 4 and detecting the capacitor fixing moving electrode 7, all etched processing of remainder is on same silicon chip.Drive mass elastic supporting beams 1 and detect mass elastic supporting beams 2 and be bonded on respectively on the anchor point 9 and anchor point 11 of glass substrate, the whole silicon wafer plane is unsettled parallel with respect to the glass substrate plane, drives the fixed electorde 4 of electric capacity and the fixed electorde 7 of detection electric capacity and also is fixed on the glass substrate.

Drive mass 3 under the constraint that drives mass elastic supporting beams 1, can only carry out the motion of x direction, detect mass 8 under the constraint that detects mass elastic supporting beams 2, can only carry out the motion of y direction.When driving mass 3 carries out the motion of x direction under the effect of static driven power, drive isolation mass 10 and do identical motion, because the x direction isolation elastic supporting beams 12 of isolating on the mass 10 is very low in the equivalent stiffness of x direction, and it is very big in the equivalent stiffness of x direction to detect mass elastic supporting beams 2, therefore isolate the mass 10 relative masses 8 that detect and make elastic movement, the motion of x direction can't be delivered to and detect on the mass 8, detect mass 8 transfixions.

When the z direction of principal axis has the angular velocity input, isolate mass 10 and be subjected to axial coriolis force effect along y, force and isolate mass 10 along y direction of principal axis up-down vibration, because the x direction isolation elastic supporting beams 12 of isolating on the mass 10 is very big in the equivalent stiffness of y direction, and it is very little in the equivalent stiffness of y direction to detect mass elastic supporting beams 2, therefore isolates mass 10 drive detection masses 8 and makes elastic movement along the y direction.On the other hand, the y direction isolation elastic supporting beams 13 of isolating on the mass 10 is very low in the equivalent stiffness of y direction, and the y direction motion of isolating mass 10 also can't be delivered to and drive on the mass 3.By of the variation of detection fixed electorde 7, can realize the detection of z axis angular rate with the differential capacitor amount of movable electrode 6.

Claims

1, a kind of vibrating micromechanical gyro is characterized in that, this micromechanical gyro comprises driving mass, detection mass, isolation mass, driving capacitor fixing electrode, drives electric capacity movable electrode, detection capacitor fixing electrode and detection electric capacity movable electrode; Described driving mass is fixed on the anchor point of micromechanical gyro glass substrate by driving elastic beam; Described detection mass and isolation mass are positioned at and drive mass, detecting mass is fixed on the anchor point of micromechanical gyro glass substrate by detecting elastic beam, described isolation mass is isolated elastic supporting beams and is driven the mass relative fixed by the y direction, and isolates elastic supporting beams and detect the mass relative fixed by the x direction; Detect the capacitor fixing electrode and be positioned at the detection mass with detection electric capacity movable electrode, the fixed electorde that detects electric capacity is fixed on the micromechanical gyro glass substrate, detects the movable electrode and the detection mass relative fixed of electric capacity; Described driving electric capacity movable electrode and driving mass relative fixed, the fixed electorde that drives electric capacity is fixed on the micromechanical gyro glass substrate.