CN212320730U

CN212320730U - Three-axis MEMS gyroscope

Info

Publication number: CN212320730U
Application number: CN202021361392.1U
Authority: CN
Inventors: 苏岩
Original assignee: Suzhou Gst Infomation Technology Co ltd
Current assignee: Suzhou Gst Infomation Technology Co ltd
Priority date: 2020-07-13
Filing date: 2020-07-13
Publication date: 2021-01-08
Anticipated expiration: 2030-07-13

Abstract

The utility model discloses a triaxial MEMS gyroscope, the structure includes basement and four quality pieces, four quality pieces suspend and set up on the basement in the central symmetry mode, still include the anchor point structure that is used for realizing being connected between basement and quality piece, the decoupling zero tie-beam structure that is used for making quality piece can vibrate along the orthogonal direction and the broach structure that is used for realizing angular velocity detection; every quality piece all hangs on the basement through the anchor point structure, connects through decoupling zero tie beam structure realization between the four quality pieces, and the broach structure arranges in the quality piece. The utility model discloses a four quality structures of symmetry formula, its vibration mode has combined tuning fork gyroscope's high sensitivity and the little frequency difference that symmetrical structure brought, has the high and big advantage of angle gain of detectivity concurrently.

Description

Three-axis MEMS gyroscope

Technical Field

The utility model relates to a gyroscope equipment especially relates to a triaxial MEMS gyroscope based on triaxial angular velocity input in torsional vibration mode detects, belongs to micro-electromechanical system technical field.

Background

MEMS (Micro-Electro-Mechanical Systems) gyroscopes are a common inertial element in Micro-electromechanical Systems for measuring angular velocity, and in general, the basic operating principle of such gyroscopes relies on the sinusoidal coriolis force generated by the vibration of a sensitive mass when angular velocity is input.

In a common MEMS gyroscope structure, a proof mass is suspended above a substrate by a system of flexible beams, leaving the proof mass free to oscillate in two orthogonal directions (drive and sense). The whole power system can be simplified into a mass spring damper system with multiple degrees of freedom, wherein the Coriolis force caused by the rotation angular velocity can transfer energy from a driving mode to a corresponding detection mode, and the energy is proportional to the input angular velocity.

For most micromechanical vibratory rate gyroscopes, the sensitive mass is driven into resonance in the driving direction by an external sinusoidal electrostatic or electromagnetic force, and as the gyroscope rotates, a sinusoidal coriolis force at the driving frequency is induced in a direction orthogonal to the driving vibration velocity and angular velocity axes, specifically expressed as the coriolis force

。

Although many MEMS gyroscopes in the prior art can achieve the function of mode detection, there are still problems in terms of complex structure, vulnerability, high production cost, poor sensitivity and precision, etc. when they are actually applied.

In summary, in view of the demand of the current market for the gyroscope in terms of functions and the common problems in some technical layers, how to provide a three-axis MEMS gyroscope with a simple and compact structure, low cost and high sensitivity so as to significantly improve the use effect of the gyroscope becomes a problem to be solved urgently by those skilled in the art.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, the present invention is directed to a three-axis MEMS gyroscope based on three-axis angular velocity input in torsional vibration mode detection, as follows.

A triaxial MEMS gyroscope comprises a substrate, four mass blocks, an anchor point structure, a decoupling connecting beam structure and a comb tooth structure, wherein the four mass blocks are arranged on the substrate in a suspended manner in a centrosymmetric manner, the anchor point structure is used for realizing connection between the substrate and the mass blocks, the decoupling connecting beam structure is used for enabling the mass blocks to vibrate along orthogonal directions, and the comb tooth structure is used for realizing angular velocity detection;

every the quality piece all through anchor point structure hangs in on the basement, four realize connecting through the decoupling zero tie-beam structure between the quality piece, the broach structure arrange in the quality piece.

Preferably, the substrate is square, a three-dimensional space coordinate system including an X axis, a Y axis and a Z axis is established by taking a central point of the substrate as an origin, the X axis and the Y axis are parallel to the end face of the substrate, and the Z axis is perpendicular to the end face of the substrate;

the four mass blocks are in a group in pairs, the two groups of mass blocks are respectively arranged symmetrically about the X axis and the Y axis, and the four mass blocks are integrally in central symmetry about the origin.

Preferably, four the shape of quality piece is unanimous, all is isosceles trapezoid, every the quality piece all contains two isometric hypotenuses, a minor face and a long limit, four the minor face of quality piece all is pressed close to the central point of base, four the long limit of quality piece all is kept away from the central point of base.

Preferably, the anchor point structure comprises four inner anchor points arranged at the inner center position of the substrate and eight outer anchor points arranged at the peripheral edge position of the substrate;

the four inner anchor points are integrally in central symmetry about the origin, and each inner anchor point and an adjacent inner anchor point are both symmetrical about the X axis or the Y axis;

the eight outer anchor points are centrosymmetric with respect to the origin, the eight outer anchor points are grouped in pairs, each group of the outer anchor points is arranged at the edge of one edge of the substrate, and the two outer anchor points in each group are symmetric with respect to the X axis or the Y axis.

Preferably, each internal anchor point is arranged between two adjacent mass blocks and is close to the short side of each mass block, each group of external anchor points is matched and corresponding to one mass block, and each group of external anchor points is close to the long side of one mass block respectively;

each mass block is supported and suspended above the substrate by two inner anchor points and a group of outer anchor points.

Preferably, the decoupling connecting beam structure includes a plurality of bidirectional U-shaped beams, four U-shaped folding beams, and four central flexible beams, and the four mass blocks are coupled through the central flexible beams in a combined connection state of the decoupling connecting beam structure.

Preferably, each of the inner anchors is connected to two adjacent masses through two of the bidirectional U-shaped beams, respectively, and each of the outer anchors is connected to one of the masses through one of the bidirectional U-shaped beams;

the U-shaped folding beams are arranged on one side of the short edge of the mass block, the four U-shaped folding beams are integrally centrosymmetric about the original point, the four U-shaped folding beams are grouped in pairs, each group of U-shaped folding beams are respectively arranged along the X axis or the Y axis, and each U-shaped folding beam is connected to two bidirectional U-shaped beams which are connected with the inner anchor point and the mass block and are arranged on the same side;

the center flexible beam is arranged at the center inside the substrate, the four center flexible beams are integrally in central symmetry relative to the original point, the four center flexible beams are in a group in pairs, each group of the center flexible beams are respectively arranged along the X axis or the Y axis, one ends of the four center flexible beams are connected above the central point of the substrate, the other ends of the four center flexible beams are respectively connected to the symmetrical center of one U-shaped folding beam, and each center flexible beam is connected with the two bidirectional U-shaped beams through one U-shaped folding beam.

Preferably, the comb tooth structure comprises a driving comb tooth, a driving detection comb tooth and a detection comb tooth; the comb tooth structures on a single mass block are symmetrical about the central axis of the mass block.

Preferably, two rows of the driving comb teeth are arranged at the edge position of each bevel edge on each mass block, four rows of the driving comb teeth are arranged in the same mass block, and a gap is reserved between the two rows of the driving comb teeth arranged at the edge position of the same bevel edge on the same mass block;

two rows of the driving detection comb teeth are respectively arranged at the position of the middle edge of the long edge of each mass block, and the two rows of the driving detection comb teeth are arranged side by side;

every the both sides edge position department on the long limit has arranged a set ofly respectively on the quality piece detect the broach, it is same two sets of on the quality piece detect the broach symmetry setting, every group all include a set of two-way broach and a set of one-way broach in the detection broach.

Compared with the prior art, the utility model discloses an advantage mainly embodies in following several aspects:

the utility model provides a MEMS gyroscope utilizes the flexible roof beam in center to realize X, Y, Z triaxial direction's angular velocity decoupling zero to make the gyroscope possess the function that triaxial angular velocity detected. And the utility model discloses a four mass structure of symmetry formula, its vibration mode has combined tuning fork gyroscope's high sensitivity and the little frequency difference that symmetrical structure brought, has the high and big advantage of angle gain of detectivity concurrently.

And simultaneously, the utility model discloses an among the hardware architecture, the drive broach with detect the broach equipartition and put at the within range of quality piece for the overall structure of gyroscope is retrencied more and is compacter, has satisfied the user demand of instrument miniaturization, high performance.

Furthermore, the utility model discloses also for other technical scheme in the same field provide the reference basis, can expand the extension on this basis, apply to in other technical scheme relevant with the MEMS gyroscope, specific very high use and spreading value.

The following detailed description is made of specific embodiments of the present invention with reference to the accompanying drawings, so as to make the technical solution of the present invention easier to understand and master.

Drawings

Fig. 1 is a schematic view of the overall structure of the present invention;

fig. 2 is one of the schematic partial enlarged structural views of the present invention;

fig. 3 is a second schematic view of the partial enlarged structure of the present invention;

fig. 4 is a third schematic view of the partially enlarged structure of the present invention;

FIG. 5 is a fourth schematic view of the enlarged partial structure of the present invention;

fig. 6 is a schematic view of the overall structure of the present invention in the working mode;

fig. 7 is a schematic view of the overall structure of the present invention in the Z-axis detection mode;

fig. 8 is a schematic view of the overall structure of the present invention in the X-axis detection mode;

fig. 9 is the overall structure diagram of the utility model in the Y-axis detection mode.

Wherein: 001. a bidirectional U-shaped beam; 002. a U-shaped folding beam; 003. a central flexible beam; 100. a mass block; 201. an internal anchor point; 202. an external anchor point; 301. Driving the comb teeth; 302. driving the detection comb teeth; 303. and detecting comb teeth.

Detailed Description

The utility model discloses a triaxial MEMS gyroscope based on triaxial angular velocity input among torsional vibration mode detection has realized the function that detects X, Y, Z triaxial angular velocity on the monolithic chip, has kept instrument overall structure's compactness, has realized the effect of high sensitivity and high gain simultaneously. The structure is as follows.

As shown in fig. 1 to 5, a three-axis MEMS gyroscope includes a substrate and four mass blocks 100, in this embodiment, the substrate is integrally processed by a silicon material, and the silicon material may be single crystal silicon or polysilicon or other doped silicon. In addition, other materials having equivalent effects may be used as the material of the substrate. The four mass blocks 100 are suspended on the substrate in a centrosymmetric manner, and further include anchor point structures for realizing connection between the substrate and the mass blocks 100, decoupling connecting beam structures for enabling the mass blocks 100 to vibrate in orthogonal directions, and comb tooth structures for realizing angular velocity detection.

Each mass block 100 is hung on the substrate through the anchor point structure, four mass blocks 100 are connected through the decoupling connecting beam structure, and the comb tooth structure is arranged in the mass block 100. In addition, it should be noted that, in the structure of the present invention, except the anchor point structure, the rest of the parts are suspended on the substrate and are integrally in central symmetry.

The substrate is square, a three-dimensional space coordinate system comprising an X axis, a Y axis and a Z axis is established by taking the central point of the substrate as an origin, the X axis and the Y axis are parallel to the end face of the substrate, and the Z axis is perpendicular to the end face of the substrate.

The four mass blocks 100 are grouped in pairs, the two mass blocks 100 are respectively arranged symmetrically about the X axis and the Y axis, and the four mass blocks 100 are centrosymmetrically about the origin.

Four the shape of quality piece 100 is unanimous, all is isosceles trapezoid, every quality piece 100 all contains two isometric hypotenuses, a minor face and a long limit, four the minor face of quality piece 100 all is pressed close to the central point of base, four the long limit of quality piece 100 all is kept away from the central point of base.

The anchor point structure comprises four inner anchor points 201 arranged at the inner center of the substrate and eight outer anchor points 202 arranged at the periphery of the substrate.

The four internal anchor points 201 are centrally symmetrical with respect to the origin, and each internal anchor point 201 and an adjacent internal anchor point 201 are symmetrical with respect to the X axis or the Y axis.

The eight outer anchor points 202 are centrosymmetric with respect to the origin, every two of the eight outer anchor points 202 form a group, each group of the outer anchor points 202 is respectively arranged at the edge position of one edge on the substrate, and the two outer anchor points 202 in each group are symmetric with respect to the X axis or the Y axis.

Every interior anchor point 201 all sets up adjacent two between the quality piece 100 and press close to the minor face of quality piece 100, every group outer anchor point 202 all with one the quality piece 100 matches and corresponds, every group outer anchor point 202 presses close to one respectively the long limit of quality piece 100.

Each of the proof-masses 100 is supported and suspended above the substrate by two of the inner anchors 201 and a set of the outer anchors 202.

The decoupling connecting beam structure comprises a plurality of bidirectional U-shaped beams 001, four U-shaped folding beams 002 and four decoupling beams 003, and the mass blocks 100 are coupled through the decoupling beams 003 in the combined connection state of the decoupling connecting beam structure.

Each of the inner anchors 201 is connected to two adjacent masses 100 through two of the bidirectional U-shaped beams 001, respectively, and each of the outer anchors 202 is connected to one of the masses 100 through one of the bidirectional U-shaped beams 001.

U type folding beam 002 set up in the minor face one side of quality piece 100, four U type folding beam 002 is whole about the initial point is central symmetry, four two liang of U type folding beam 002 are a set of, every group U type folding beam 002 follows respectively the X axle or the Y axle sets up, every U type folding beam 002 all is connected to two of homonymy and is connected with interior anchor point 201 reaches quality piece 100 two-way U type beam 001.

Decoupling zero roof beam 003 set up in the inside central point of basement puts the utility model discloses an in-service application process, decoupling zero roof beam 003 only transmits axial motion, does not transmit the axial and rotates to two direction angular velocity's in plane independent detection has been realized. Four decoupling beam 003 is whole about the initial point is central symmetry, four two liang of decoupling beam 003 is a set of, every group decoupling beam 003 follows respectively the X axle or the Y axle sets up, four the one end homogeneous phase of decoupling beam 003 connect in central point top, four of basement the other end of decoupling beam 003 is connected to one respectively the center of symmetry of U type folding beam 002, every decoupling beam 003 all is through one U type folding beam 002 and two-way U type roof beam 001 is connected.

The comb structure comprises a driving comb 301, a driving detection comb 302 and a detection comb 303. The comb structures on a single mass 100 are symmetrical about the central axis of the mass 100. In this embodiment, the driving manner for the mass 100 includes, but is not limited to, electrostatic force driving.

Two rows of driving comb teeth 301 are arranged at the edge position of each oblique edge of each mass block 100, a total of four rows of driving comb teeth 301 are arranged in the same mass block 100, a gap is reserved between the two rows of driving comb teeth 301 arranged at the edge position of the same oblique edge of the same mass block 100, and different voltages can be applied when electrostatic force driving is performed.

Two rows of the driving detection comb teeth 302 are respectively arranged at the middle edge position of the long edge of each mass block 100, and the two rows of the driving detection comb teeth 302 are arranged side by side.

The detection comb teeth 303 are arranged at the edge positions of two sides of the long edge of each mass block 100, the detection comb teeth 303 are mainly used for detecting angular velocity input in the Z-axis direction, specifically, the coriolis force caused by the angular velocity in the Z-axis direction is detected to enable the displacement of the mass block 100 to be generated, and the detection mode includes but is not limited to variable-pitch capacitance detection. It is same two sets of on the quality piece 100 detect the broach 303 symmetry setting, every group all include a set of two-way broach and a set of one-way broach in the detection broach 303.

In the hardware structure of the present invention, each of the mass blocks 100 is driven by the corresponding driving comb 301, i.e., the mass block 100 vibrates in a simple harmonic manner.

As shown in fig. 6 to 9, the above-mentioned schemes are functionally described below with reference to descriptions of various operation modes of the present invention in practical application.

When the utility model discloses a triaxial MEMS gyroscope is in during operation mode, drive detection broach 302 is through variable area capacitance proof mass piece displacement in the drive direction, provides the controller with the signal, and the required drive closed loop of operation mode is accomplished to the controller.

At this time, when an angular velocity of the Z-axis (vertical resonator plane) is input, the mass 100 transfers energy from the operating mode to the Z-axis detection mode under the action of coriolis force. The Z-axis detection mode is a telescopic mode, i.e. all the masses 100 exhibit the same direction of movement away from or close to the center. Specifically, in the working mode, the mass block 100 moves in a tangential direction, and the coriolis force applied to the mass block 100 is in a radial direction under the action of the Z-axis angular velocity. Because the masses 100 move in the same direction in the working mode, all the masses 100 are subjected to the same direction of coriolis force, and show periodic movement away from or close to the center of the gyroscope, and the Z-axis detection mode shows a telescopic mode under the coupling of the decoupling beams 003.

In the Z-axis detection mode, the detection comb 303 detects the displacement of the mass block 100 in the Z-axis input sensitive direction (radial direction) through the variable-pitch capacitor, and provides a signal to the processor, and the processor obtains the magnitude of the Z-axis angular velocity input through calculation.

In the working mode, when an angular velocity of the X axis (parallel to the plane of the resonator) is input, the mass block 100 transfers energy from the working mode to the X axis detection mode under the action of coriolis force. The X-axis detection mode is a dual-mass oscillation mode, that is, both the masses 100 in the X-axis direction oscillate away from or close to the resonator plane in opposite directions, wherein the displacement of the short side of the mass 100 is the largest, and the displacement of the long side of the mass 100 is the smallest.

Under X axle detection mode, be located triaxial MEMS gyroscope below detection electrode detect out through variable-spacing electric capacity the displacement of quality piece 100 on X axle input sensitive direction (Z axle) to with signal supply treater, the treater obtains the size of X axle angular velocity input through calculating.

In the working mode, when an angular velocity of the Y axis (parallel to the plane of the resonator) is input, the mass block 100 transfers energy from the working mode to the Y axis detection mode under the action of coriolis force. The Y-axis detection mode is a dual-mass oscillation mode, that is, both the masses 100 in the Y-axis direction oscillate away from or close to the resonator plane in opposite directions, wherein the displacement of the short side of the mass 100 is the largest, and the displacement of the long side of the mass 100 is the smallest.

Under Y axle detection mode, be located the detection electrode of triaxial MEMS gyroscope below detect out through variable-spacing electric capacity the displacement of quality piece 100 in Y axle input sensitive direction (Z axle) to with signal supply treater, the treater obtains the size of Y axle angular velocity input through calculating.

In the working mode, the common center of the four decoupling beams 003 is also twisted, and the U-beam structure of each decoupling beam 003 releases the displacement caused by the twisting of the mass 100, so that the twisting motions do not interfere with each other.

In the Z-axis detection mode, the common center of the four decoupling beams 003 is balanced in force, and each decoupling beam 003 releases the radial displacement of the mass block 100, and converts part of kinetic energy into elastic potential energy, which acts as a force effect in the beam direction.

In the detection mode of the X/Y axis, the common center of the four decoupling beams 003 is balanced in force, and each decoupling beam 003 releases the movement displacement of the mass block 100 and converts part of kinetic energy into elastic potential energy, thereby playing a role in transferring the force in the beam direction.

As can be seen from the above description, the decoupling beam 003 specifically functions to release the torsional displacement in the working mode and transmit the force in the beam direction in each detection mode.

To sum up, the utility model provides a MEMS gyroscope utilizes the angular velocity decoupling zero of flexible roof beam realization X, Y, Z triaxial direction in center to make the gyroscope possess the function that triaxial angular velocity detected. And the utility model discloses a four mass structure of symmetry formula, its vibration mode has combined tuning fork gyroscope's high sensitivity and the little frequency difference that symmetrical structure brought, has the high and big advantage of angle gain of detectivity concurrently.

It is obvious to a person skilled in the art that the invention is not restricted to details of the above-described exemplary embodiments, but that it can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein, and any reference signs in the claims are not intended to be construed as limiting the claim concerned.

Finally, it should be understood that although the present description refers to embodiments, not every embodiment contains only a single technical solution, and such description is for clarity only, and those skilled in the art should integrate the description, and the technical solutions in the embodiments can be appropriately combined to form other embodiments understood by those skilled in the art.

Claims

1. A three-axis MEMS gyroscope, comprising: the vibration sensor comprises a substrate and four mass blocks (100), wherein the four mass blocks (100) are arranged on the substrate in a suspended manner in a centrosymmetric manner, and further comprises an anchor point structure for realizing connection between the substrate and the mass blocks (100), a decoupling connecting beam structure for enabling the mass blocks (100) to vibrate along the orthogonal direction and a comb tooth structure for realizing angular velocity detection;

each mass block (100) is hung on the substrate through the anchor point structure, the four mass blocks (100) are connected through the decoupling connecting beam structure, and the comb tooth structure is arranged in the mass block (100).

2. The three-axis MEMS gyroscope of claim 1, wherein: the substrate is square, a three-dimensional space coordinate system comprising an X axis, a Y axis and a Z axis is established by taking the central point of the substrate as an origin, the X axis and the Y axis are parallel to the end face of the substrate, and the Z axis is vertical to the end face of the substrate;

the four mass blocks (100) are divided into a group in pairs, the two groups of mass blocks (100) are respectively arranged symmetrically about the X axis and the Y axis, and the four mass blocks (100) are integrally centrosymmetric about the origin.

3. The three-axis MEMS gyroscope of claim 2, wherein: four the shape of quality piece (100) is unanimous, all is isosceles trapezoid, every quality piece (100) all contains two isometric hypotenuses, a minor face and a long limit, four the minor face of quality piece (100) is all pressed close to the central point of base, four the long limit of quality piece (100) is all kept away from the central point of base.

4. The three-axis MEMS gyroscope of claim 3, wherein: the anchor point structure comprises four inner anchor points (201) arranged at the inner center position of the substrate and eight outer anchor points (202) arranged at the peripheral edge position of the substrate;

the four internal anchor points (201) are centrally symmetrical about the origin in whole, and each internal anchor point (201) and an adjacent internal anchor point (201) are symmetrical about the X axis or the Y axis;

the eight outer anchor points (202) are centrosymmetric with respect to the origin, the eight outer anchor points (202) form a group in pairs, each group of outer anchor points (202) is arranged at the edge position of one edge on the substrate, and the two outer anchor points (202) in each group are symmetric with respect to the X axis or the Y axis.

5. The tri-axial MEMS gyroscope of claim 4, wherein: each internal anchor point (201) is arranged between two adjacent mass blocks (100) and is close to the short side of each mass block (100), each group of external anchor points (202) is matched and corresponding to one mass block (100), and each group of external anchor points (202) is close to the long side of one mass block (100) respectively;

each mass block (100) is supported and suspended above the substrate by two inner anchor points (201) and a group of outer anchor points (202).

6. The tri-axial MEMS gyroscope of claim 5, wherein: decoupling zero tie beam structure includes a plurality of two-way U type roof beam (001), four U type folding beam (002) and four decoupling zero roof beam (003) under the built-up connection state of decoupling zero tie beam structure, four quality piece (100) pass through decoupling zero roof beam (003) are coupled mutually.

7. The tri-axial MEMS gyroscope of claim 6, wherein: each of the internal anchor points (201) is connected to two adjacent masses (100) by two of the bidirectional U-shaped beams (001), and each of the external anchor points (202) is connected to one of the masses (100) by one of the bidirectional U-shaped beams (001);

the U-shaped folding beams (002) are arranged on one side of the short edge of the mass block (100), the four U-shaped folding beams (002) are integrally in central symmetry about the original point, every two of the four U-shaped folding beams (002) form a group, each group of U-shaped folding beams (002) are respectively arranged along the X axis or the Y axis, and each U-shaped folding beam (002) is connected to two bidirectional U-shaped beams (001) which are connected with the inner anchor point (201) and the mass block (100) and are arranged on the same side;

decoupling zero roof beam (003) set up in the inside central point of basement puts, four decoupling zero roof beam (003) whole about the origin is central symmetry, four decoupling zero roof beam (003) two liang are a set of, every group decoupling zero roof beam (003) are followed respectively the X axle or the Y axle sets up, four the one end homogeneous phase of decoupling zero roof beam (003) connect in the central point top of basement, four the other end of decoupling zero roof beam (003) is connected to one respectively the center of symmetry of U type folding beam (002), every decoupling zero roof beam (003) all through one U type folding beam (002) and two-way U type roof beam (001) is connected.

8. The three-axis MEMS gyroscope of claim 1, wherein: the comb tooth structure comprises a driving comb tooth (301), a driving detection comb tooth (302) and a detection comb tooth (303); the comb tooth structures on a single mass (100) are symmetrical about a central axis of the mass (100).

9. The three-axis MEMS gyroscope of claim 8, wherein: two rows of driving comb teeth (301) are arranged at the edge position of each bevel edge on each mass block (100), four rows of driving comb teeth (301) are arranged in the same mass block (100), and a gap is reserved between the two rows of driving comb teeth (301) arranged at the edge position of the same bevel edge on the same mass block (100);

two rows of driving detection comb teeth (302) are respectively arranged at the middle edge position of the long edge of each mass block (100), and the two rows of driving detection comb teeth (302) are arranged side by side;

every the both sides edge position department on the long limit on the quality piece (100) has arranged a set ofly respectively detect broach (303), it is same two sets of on the quality piece (100) detect broach (303) symmetry setting, every group all include a set of two-way broach and a set of one-way broach in detecting broach (303).