CN1598597A

CN1598597A - Single mass plate triaxial micro-mechanical accelerometer

Info

Publication number: CN1598597A
Application number: CN 200410026336
Authority: CN
Inventors: 苑伟政; 常洪龙
Original assignee: Northwestern Polytechnical University
Current assignee: Northwestern Polytechnical University
Priority date: 2004-07-19
Filing date: 2004-07-19
Publication date: 2005-03-23
Anticipated expiration: 2024-07-19
Also published as: CN1332205C

Abstract

The invention discloses a simple mass flat triaxiality tiny machine accelerometer, the mass flat is supported on the fundus by four groups of inner girder and four groups of outer girder, and four groups of comb is protruded on four directions, which cross to four groups of terminal comb on the fundusby to produce four couples of comb capacitor---capacitor C40a, capacitor C40b, capacitor C42a, and capacitor C42b, capacitor C42b and the capacitor C42b is equal to capacitor Cx which is along X direction, the capacitor C40a and the capacitor C40b are equal to capacitor Cy which is along to direction Y, its character is: it also includes a junior board which is under the mass flat, and composes a clinograph capacitor Cz with the mass flat, and the Cz, the Cx and the Cy compose the triaxiality accelerometer. The four groups of comb on the mass flat and the four groups of comb on the funduusby and the junior board are machining on one chip. The excellence of the invention is a mass flat can get linear acceleration on three directions X, Y, Z, and its size is tiny, its weight is light.

Description

Dull and stereotyped three micro-mechanical accelerometers of simple substance amount

Technical field

The present invention proposes dull and stereotyped three micro-mechanical accelerometers of a kind of simple substance amount, belongs to little inertia device technical field.

Background technology

With reference to Fig. 5.The Said Emre Alper of Turkey's Middle East Technical University has proposed a kind of symmetrical expression in Transducer 2001 meetings structure is used for measuring around Z-direction, i.e. the angular velocity of importing perpendicular to the direction of quality flat board.In this structure, the inertial mass flat board is supported by four groups of inner beams and four groups of outer beams.Stretch out four groups of broach around the quality flat board, respectively with four fixed electordes on every side on the broach that stretches out intersect and constituted four pairs of broach capacitors.Its principle of work is: the quality flat board is subjected to acting in the XY plane of electrostatic force, and promptly simple harmonic oscillation is done along directions X in plane, the dull and stereotyped place of quality.This moment is if the Z direction of winding perpendicular to the quality flat board has angular velocity input, then because coriolis effect, the quality flat board will have a motion in the Y direction perpendicular to the XZ plane, thereby change the size of formed broach electric capacity between quality flat board and the respective fixation electrode.This capacitance variations has comprised the angular velocity information of input, can try to achieve the angular velocity of importing around the Z axle by it being detected with demodulation.

The proposition of this structure is what to be used for measuring around the angular velocity of Z axle.But in this structure, four pairs of broach capacitors that the dull and stereotyped and corresponding fixed electorde of quality is constituted are to the motion sensitive of quality flat board on X, Y direction, and its structure can be used as the twin-axis accelerometer of responsive X, Y both direction linear acceleration simultaneously.But this structure can not responsive Z direction linear acceleration.

Summary of the invention

The object of the present invention is to provide dull and stereotyped three micro-mechanical accelerometers of a kind of simple substance amount, by below its quality flat board, increasing the linear acceleration that a battery lead plate comes enough responsive Z directions, responsive X, Y, three directional ray acceleration of Z simultaneously.

The technical solution adopted for the present invention to solve the technical problems is: dull and stereotyped three micro-mechanical accelerometers of a kind of simple substance amount, the quality flat board is supported in the substrate by four groups of inner beams and four groups of outer beams, four groups of broach that the quality flat board stretches out to four direction, respectively be fixed on the broach that stretches out on suprabasil four electrodes and intersect and constituted four pairs of broach capacitors---capacitor C40a, capacitor C40b, capacitor C42a and capacitor C42b, capacitor C42a and capacitor C42b equivalence are the capacitor Cx along directions X, capacitor C40a and capacitor C40b equivalence are the capacitor Cy along the Y direction, it is characterized in that: also comprise a bottom crown that is positioned at below the quality flat board, quality is dull and stereotyped to constitute plane-parallel capacitor Cz, capacitor Cz and capacitor Cx with bottom crown, capacitor Cy constitutes three axis accelerometer together.

Four groups of broach that described quality flat board stretches out to four direction be fixed on suprabasil four pairs of broach and bottom crown, by microfabrication on a chip.

The invention has the beneficial effects as follows, can be by a quality dull and stereotyped responsive X, Y, three directional ray acceleration of Z simultaneously, and the three axis accelerometer of simple substance amount flat board just can be realized three accelerometer on a chip by Micrometer-Nanometer Processing Technology, aligning between each guarantees by structural design, avoided assembly problem, and can reduce volume and weight, can dwindle area of chip.

Description of drawings

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

Fig. 2 is the A-A ' cut-open view of Fig. 1

Fig. 3 is the equivalent electrical model of simple substance amount flat board in the XY plane

Fig. 4 is the equivalent electrical model of simple substance amount flat board

Fig. 5 is the Z axle gyro structural representation of Said, is prior art figure

Among the figure: 18. substrates, 40a. fixed electorde I, 40b. fixed electorde II, 42a. fixed electorde III, 42b. fixed electorde IV, 41a. comb electrodes I, 41b. comb electrodes II, 41c. comb electrodes III, 41d. comb electrodes IV, 44.y the outer beam I of direction, the outer beam I of 45.x direction, the outer beam II of 46.x direction, 47.y the outer beam II of direction, the outer beam III of 48.y direction, the outer beam III of 49.x direction, 50.x the outer beam IV of direction, the outer beam IV of 51.y direction, 52.x direction inner beam I, 53.y direction inner beam I, 54.y direction inner beam II, 55.x direction inner beam II, 56.x direction inner beam III, 57.y direction inner beam III, 58.y direction inner beam IV, 59.x direction inner beam IV, 60. the quality flat board, 61. bottom crowns.

Embodiment

With reference to Fig. 1～4.The present invention adopts symmetrical structure, and quality dull and stereotyped 60 is passed through by the outer beam I44 of y direction, the outer beam I45 of x direction, the outer beam II46 of x direction, the outer beam II47 of y direction, the outer beam III of 48.y direction, 49.x the outer beam III of direction, the outer beam IV of 50.x direction, the outer beam IV of 51.y direction, 52.x direction inner beam I, y direction inner beam I53, y direction inner beam II54, x direction inner beam II55, x direction inner beam III56, y direction inner beam III57, y direction inner beam IV58, the brace summer that x direction inner beam IV59 is formed suspends and is affixed in the substrate 18.Stretch out four groups of broach: comb electrodes I41a around the quality flat board 60 respectively, comb electrodes II41b, comb electrodes III41c, comb electrodes IV41d is respectively with fixed electorde I42a, fixed electorde II40a, fixed electorde III42b, the broach that stretches out on fixed electorde IV40b intersection has constituted four couples of broach capacitor C40a as shown in Figure 3, C40b, C42a, C42b.While quality dull and stereotyped 60 and bottom crown 61 formation plane-parallel capacitor Cz as shown in Figure 4.

The inertial force that is subjected to directions X when quality flat board 60 is done the time spent, and the outer beam I44 of y direction, the outer beam II47 of y direction, the outer beam III48 of y direction, the outer beam IV51 of y direction and y direction inner beam I53, y direction inner beam II54, y direction inner beam III57, y direction inner beam IV58 bend in the XY plane.And the outer beam I45 of x direction, the outer beam II46 of x direction, outer beam III49 of x direction and the outer beam IV50 of x direction are for broach capacitor C40a, and C40b is a compression rod in the change of directions X, and rigidity is very big, thereby has limited broach capacitor C40a, and C40b is in the change of directions X.Simultaneously because quality flat board 60 is not subjected to the component of Y direction. so broach capacitor C40a, C40b does not have displacement in the Y direction yet.And beam I44, the outer beam II47 of y direction, the outer beam III48 of y direction, the outer beam IV51 of y direction are for broach capacitor C42a outside the y direction, and the change of C42b on the Y direction is depression bar, and rigidity is very big.Thereby broach capacitor C42a is only arranged, and C42b has displacement at directions X.By responsive broach capacitor C42a, the variation of C42b on directions X can be tried to achieve the component of acceleration of directions X.

In like manner, when quality flat board 60 is subjected to the inertial force of Y direction, the outer beam I45 of x direction, the outer beam II46 of x direction, outer beam III49 of x direction and the outer beam IV50 of x direction, and four inner beam x direction inner beam I52, x direction inner beam II55, x direction inner beam III56, x direction inner beam IV59 bend in the XY plane.And beam I44, the outer beam II47 of y direction, the outer beam III48 of y direction, the outer beam IV51 of y direction have limited broach capacitor C42a outside the y direction, and C42b is in the displacement of Y direction.The outer beam I45 of x direction, the outer beam II46 of x direction, outer beam III49 of x direction and the outer beam N50 of x direction have limited broach capacitor C40a, and C40b is in the displacement of directions X, thus feasible only have broach capacitor C40a, and C40b changes on the Y direction.Can obtain the component of acceleration of Y direction by this variation of sensitivity.

When quality flat board 60 was subjected to the inertial force of Z direction, all outer beams and inner beam were in the direction bending perpendicular to the XY plane.And inner beam and outer beam are because pressurized has limited the degree of freedom of quality flat board at in-plane.Thereby only there is broach capacitor Cz on the Z direction, to change.By responsive this changes in capacitance, can try to achieve the component of acceleration of Z direction.

Claims

1, dull and stereotyped three micro-mechanical accelerometers of a kind of simple substance amount, the quality flat board is supported in the substrate by four groups of inner beams and four groups of outer beams, four groups of broach that the quality flat board stretches out to four direction, respectively be fixed on the broach that stretches out on suprabasil four electrodes and intersect and constituted four pairs of broach capacitors---capacitor C40a, capacitor C40b, capacitor C42a and capacitor C42b, capacitor C42a and capacitor C42b equivalence are the capacitor Cx along directions X, capacitor C40a and capacitor C40b equivalence are the capacitor Cy along the Y direction, it is characterized in that: also comprise a bottom crown that is positioned at below the quality flat board, quality is dull and stereotyped to constitute plane-parallel capacitor Cz, capacitor Cz and capacitor Cx with bottom crown, capacitor Cy constitutes three axis accelerometer together.

2, single mass three-shaft micro-mechanical accelerometer according to claim 1, it is characterized in that: four groups of broach that described quality flat board stretches out to four direction be fixed on suprabasil four pairs of broach and bottom crown, by microfabrication on a chip.