CN106871887B

CN106871887B - Vibration module and gyroscope

Info

Publication number: CN106871887B
Application number: CN201510915890.3A
Authority: CN
Inventors: 裘进; 郭慧芳
Original assignee: Qst Corp [cn/cn]
Current assignee: Shanghai Sirui Technology Co.,Ltd.
Priority date: 2015-12-10
Filing date: 2015-12-10
Publication date: 2020-02-18
Anticipated expiration: 2035-12-10
Also published as: CN106871887A

Abstract

A vibration module is arranged in an XY plane and comprises a resonance component, wherein the resonance component is arranged at the tail end of a cantilever beam, the vibration module also comprises an elastic limiting component, and the resonance component is connected with an external fixed component through the elastic limiting component and the cantilever beam; the resonance part is in the vibration state along the Z direction, the cantilever beam is the first restriction power that the resonance part provided, elasticity spacing part is for the resonance part provides the second restriction power, the effect position of the resultant of first restriction power and second restriction power with the coincidence of the barycenter of resonance part, the vibration direction of resonance part is unanimous.

Description

Vibration module and gyroscope

Technical Field

The invention relates to the technical field of micromachines, in particular to a vibration module and a gyroscope.

Background

A MEMS (Micro Electro Mechanical System) gyroscope utilizes the Coriolis force phenomenon. Coriolis forces are a description of the offset of particles that move linearly in a rotating system relative to the linear motion produced by the rotating system due to inertia. The coriolis force is derived from the inertia of the motion of the object, and the particles moving linearly in the rotating system tend to continue moving along the original direction of motion due to the inertia, but since the system itself is rotating, after a period of motion, the positions of the particles in the system change, and the direction of the original motion tendency deviates to some extent if viewed from the perspective of the rotating system. The MEMS gyroscope has a small volume, low cost, and good integration, and has been widely used in mobile terminals, camera anti-shake, game pads, toy airplanes, and navigation products.

The MEMS gyroscope comprises a driving part and a detecting part, and the measurement of the angular velocity of the movement is realized through the coupling effect of the driving and detecting movements. When the gyroscope is in a driving motion mode and an angular velocity is input in a second direction perpendicular to the axial direction of the driving mode motion, the gyroscope generates a detection mode motion in a detection axial direction due to the Cogowski effect, and the rotation angular velocity of the object is instantly determined by measuring the displacement of the detection mode motion. The measuring of the displacement of the detection modal motion may be performed by measuring a change in capacitance, for example, by determining a change in capacitance resulting from the motion of the moving electrode under resonance conditions, which may be performed by interdigitated electrodes or flat electrodes.

Therefore, a spinning top usually includes at least one set of vibration modules for generating and detecting the change of vibration mode. Since it is necessary to detect the position change of the resonant member in the vibration module, the resonant member is usually rotated around a certain rotation axis, so that the position change of the resonant member is not easily detected accurately. Therefore, it is an urgent problem to be solved in the prior art to detect the position change of the resonance component more accurately.

Disclosure of Invention

The present invention is directed to a vibration module capable of detecting a change in the position of a resonance member more accurately.

In order to solve the above problems, the present invention provides a vibration module, which is disposed in an XY plane, and includes a resonance component disposed at a distal end of a cantilever beam, and an elastic limiting component, wherein the resonance component is connected to an external fixing component through the elastic limiting component and the cantilever beam; the resonance part is in under the vibration state, the cantilever beam is the first restriction power that the resonance part provided, elasticity stop part is for the resonance part provides the second restriction power, the position of action of the resultant of first restriction power and second restriction power with the barycenter coincidence of resonance part, and the direction of action with the vibration direction of resonance part is unanimous.

Optionally, the resonance component includes an electrode, and is driven by an external driving electric field through the electrode, the driving electric field applies a third limiting force to the resonance component, and the acting position of the resultant of the first limiting force, the second limiting force, and the third limiting force coincides with the centroid of the resonance component, and the acting direction is perpendicular to the XY plane.

Optionally, the elastic limiting component comprises at least one spring, one end of the spring is connected with the resonance component, and the other end of the spring is connected with the fixing component.

Optionally, the elastic limiting component comprises two springs arranged in the same plane, the axial direction of each spring is perpendicular to the vibration direction of the resonance component, and the axial directions of the two springs are arranged on the same straight line.

Optionally, the two springs arranged in the same plane have different elastic coefficients.

Alternatively, the vibration state of the resonance member includes out-of-plane vibration in the Z direction, and in-plane vibration in the XY plane.

The invention also provides a gyroscope which comprises a vibration module, a fixed part and a cantilever beam, wherein the vibration module is arranged in the XY plane and comprises a resonance part, one end of the cantilever beam is connected with the resonance part, the other end of the cantilever beam is connected with the fixed part, the vibration module also comprises an elastic limiting part, and the resonance part is connected with the fixed part through the elastic limiting part and the cantilever beam; the resonance part is in under the vibration state, the cantilever beam is the first restriction power that the resonance part provided, elasticity stop part is for the resonance part provides the second restriction power, the position of action of the resultant of first restriction power and second restriction power with the barycenter coincidence of resonance part, and the direction of action with the vibration direction of resonance part is unanimous.

Optionally, the resonance component includes a first electrode, the fixing component includes a second electrode, the two electrodes form a driving capacitor to apply a third limiting force to the resonance component, the acting positions of the resultant of the first limiting force, the second limiting force, and the third limiting force coincide with the centroid of the resonance component, and the acting direction is perpendicular to the XY plane.

The elastic limiting part is used for providing a limiting force for the resonance part to counteract the problem that the resonance part can be in a rotating state under the state that the pure cantilever beam drives the resonance part to move, so that the resonance part is in a translation state and is more easily and accurately detected.

Drawings

FIG. 1 is a schematic structural diagram of a vibration module according to an embodiment of the present invention

FIG. 2 is a schematic structural diagram of another embodiment of the vibration module of the present invention

FIG. 3 is a schematic structural diagram of another embodiment of the vibration module of the present invention

FIG. 4 is a schematic structural diagram of an embodiment of a gyroscope according to the present invention

Fig. 5, 6 and 7 are enlarged schematic views of the resonant member shown in fig. 4 in a vibrating state.

Fig. 8 is a schematic diagram of the connection between the resonator and the cross beam in the embodiment of the gyroscope according to the invention.

Detailed Description

The following describes in detail specific embodiments of the vibration module and the gyroscope according to the present invention with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of an embodiment of the vibration module according to the present invention, where the vibration module includes a resonance component 11, the resonance component 11 is disposed at a tail end of a cantilever beam 13, and the vibration module further includes an elastic limiting component, which is a spring 12a in the embodiment. The resonance part is connected to an external fixing part 10 through the elastic limiting part and the cantilever beam 13. In other embodiments, the elastic limiting component may be an elastic beam made of elastic material and capable of stretching. The resonant member 11, the cantilever beam 13, and the spring 12a of the vibration module are disposed in the same XY plane.

In a state where the resonance member 11 is vibrated in the Z direction (a direction perpendicular to the drawing), the cantilever beam 13 provides a first restriction force to the resonance member, and the spring 12a provides a second restriction force to the resonance member. If the resonant member 11 is rotated along the fixed end of the cantilever beam 13 under the driving of the cantilever beam 13 without applying a spring, the first limiting force can be decomposed into a pulling force of the cantilever beam 13 to the resonant member 11 and a twisting force of the cantilever beam 13 to the resonant member 11. A simple first limiting force will cause the resonator element 11 to turn and a second limiting force, created by the spring 12a pulling the resonator element 11, will counteract the turning effect. The vibration of the resonance component 11 is reciprocating vibration along the direction vertical to the drawing, the action position of the resultant of the first limiting force and the second limiting force coincides with the centroid of the resonance component 11, and the action direction is vertical to the XY plane, so that the vibration of the resonance component 11 can be ensured to be horizontal up and down.

For the situation that the vibration of the resonance component 11 is horizontally vibrated in the XY plane, the action position of the resultant force of the first limiting force and the second limiting force coincides with the centroid of the resonance component 11, and the action direction is parallel to the XY plane, so that the vibration of the resonance component 11 cannot rotate in the plane, the distance between the vibration and the driving electrode is changed, and a bad effect is generated on the driving.

The above effects can be obtained by adjusting the size and the spring constant of the cantilever beam and the spring constant of the position restricting part formed by the spring 12 a. For the resonant components 11 with different shapes, physical parameters such as the size and the elastic coefficient of a proper cantilever beam and the elastic coefficient of the limiting component formed by the spring 12a should be calculated according to a theoretical calculation or a computer simulation calculation mode.

In order to detect the movement of the resonator element, a first electrode 14a is typically provided on the resonator element and a second electrode 14b is provided on the outer, stationary element 10. In another embodiment, the first electrode 14a can also be used as a driving electrode. In this case, the position of action of the resultant of the first, second, and third limiting forces should be made coincident with the centroid of the resonance part 11, and the direction of action should be perpendicular to the XY plane. The first electrode 14a and the second electrode 14b are not limited to the comb-teeth electrodes shown in fig. 1, and may be a pair of plate electrodes (not shown) provided on the surface of the resonator 11 and the surface of the fixed member 10 so as to face each other, and the extending direction of the plate electrodes is in the XY plane. The comb-teeth electrodes are suitable for the drive electrodes, while the plate electrodes are suitable for the detection electrodes. The resonator element 11 is driven by a driving electric field provided by an external second electrode 14b via the first electrode 14a, the driving electric field applying a third confining force to the resonator element 11. The restraining force is actually an elastic force, which is balanced with the inertial force in the vibration mode. In the vibration mode of the resonator element 11, the parallel plates generate a negative stiffness, i.e. a negative spring force, and thus an additional restraining force. The electrostatic force of the comb teeth electrode is kept basically constant in the range of motion amplitude, so that no remarkable limiting force is generated, namely no remarkable effect is generated on the achievement of the translation condition.

As can be seen from the above description, the elastic limiting component is used to provide a limiting force for the resonant component 11 to counteract that the resonant component 11 is in a rotating state when the simple cantilever beam 13 drives the resonant component 11 to move, so that the vibration of the resonant component 11 is in a translational motion. The change in the position of the translatory resonator element 11 is more easily and accurately detected. In the embodiment with a spring as the elastic limiting member, at least one spring 12a is included, one end of which is connected to the resonance member 11 and the other end of which is connected to the fixing member 10.

Fig. 2 is a schematic structural diagram of another embodiment of the vibration module according to the present invention, which includes two

springs

22a and 22b disposed in the same plane, wherein the axial direction of each spring is perpendicular to the vibration direction of the resonant component 11, and the axial directions of the two springs are disposed on the same straight line. This arrangement can be accomplished the effect position of the resultant of first restriction power and second restriction power and the coincidence of the barycenter of resonance part 11, and the direction of action is unanimous with resonance part 11's vibration direction, can guarantee like this that resonance part 11's vibration is horizontal up-and-down or horizontal migration in the XY plane.

Fig. 3 is a schematic structural diagram of another embodiment of the vibration module according to the present invention, which includes 4

springs

32a, 32b, 32c and 32d, and is a preferred embodiment. The axial direction of each spring is perpendicular to the vibration direction of the resonance member 11, and the axial directions of the

springs

32a, 32b are arranged on the same straight line, and the axial directions of the

springs

32c, 32d are arranged on the same straight line. The arrangement mode can also ensure that the action position of the resultant force of the first limiting force and the second limiting force coincides with the mass center of the resonance component 11, and the action direction is consistent with the vibration direction of the resonance component 11, so that the vibration of the resonance component 11 can be ensured to move horizontally up and down or horizontally in the XY plane. And the second limiting force is exerted by four springs on the four corners of the resonator element 11, which is more stable and a preferred embodiment.

Next, specific embodiments of the gyroscope of the present invention will be given. Referring to fig. 4, a schematic structural diagram of an embodiment of the gyroscope of the present invention includes

resonant parts

411, 412, 413, and 414 disposed in the same plane, a fixing part 40, and an elastic limiting part formed by a spring. In the present embodiment, there are 4 movable members provided on a cross beam 43, and provided in two perpendicular directions of X and Y, respectively. The fixing member 40 is an outer frame of the spinning top.

The following explains the state of out-of-plane vibration in the Z-axis direction and the effect of the elastic stopper in the above-described configuration, taking the resonance member 411 as an example. Fig. 5 is an enlarged view of the resonance member 411 in a vibration state, and the

springs

52a, 52b, 52c, and 52d connect the resonance member 411 and the fixed member 40. The

springs

52a, 52b, 52c, and 52d provide a second restriction force to the resonance part 411. If the resonance member 411 is rotated along the fixed end of the cross beam 43 by the cross beam 43 without applying a spring. A simple first limiting force will cause the resonant member 411 to rotate, while a second limiting force, generated by the

springs

52a, 52b, 52c and 52d pulling the resonant member 411, will counteract the rotating effect. The vibration of the resonance part 411 is a reciprocating vibration along the Z direction, the action position of the resultant of the first and second limiting forces coincides with the centroid of the resonance part 411, and the action direction is perpendicular to the XY plane, so that the vibration of the resonance part 411 can be ensured to be horizontal up and down. This effect can be obtained by adjusting the size and spring constant of the cantilever beams, and the spring constant of the position restricting member constituted by the

springs

52a, 52b, 52c, and 52 d. For the resonant components 411 with different shapes, physical parameters such as the size and the elastic coefficient of the cantilever beam and the elastic coefficient of the limiting component formed by the

springs

52a, 52b, 52c and 52d should be calculated according to a theoretical calculation or a computer simulation calculation.

In order to show the vibration state of the resonator element more clearly, fig. 6 is an enlarged view of another resonator element 412 in the vibration state, and the springs 62a, 62b, 62c and 62d connect the movable element 411 and the fixed element 40. For the operation of the above structure, reference is made to the above description of the resonant part 411.

The following explains a state of the above-described structure in which in-plane vibration is performed in the directions in the XY plane and a stopper effect of the elastic stopper, by taking the resonance member 413 as an example. Fig. 7 is an enlarged schematic view of the resonator element 413 in an in-plane vibration state, wherein the

springs

72a, 72b, 72c and 72d connect the resonator element 413 to the fixing element 40. The

springs

72a, 72b, 72c, and 72d provide a second restriction force to the resonance part 413. If no spring is applied, the resonant member 411 is moved in the XY plane by the cross beam 43. The simple first restraining force is not stable enough, and a slight deviation causes the resonance member 413 to rotate, and the second restraining force generated by the

springs

72a, 72b, 72c, and 72d pulling the resonance member 413 makes the vibration member 413 more stable. If the resonant component 411 has a tendency to rotate, the four springs will generate opposite pulling forces, thereby limiting the rotation. The vibration of the resonance part 413 is in the XY plane, the position of action of the resultant of the first and second limiting forces coincides with the centroid of the resonance part 413, and the direction of action is parallel to the XY plane, so that the vibration of the resonance part 411 is ensured to be in the XY plane. This effect can be obtained by adjusting the size and spring constant of the cantilever beams, and the spring constant of the position restricting member constituted by the

springs

72a, 72b, 72c and 72 d. For the resonant component 413 with different shapes, physical parameters such as the size and the elastic coefficient of the cantilever beam and the elastic coefficient of the limiting component formed by the

springs

72a, 72b, 72c and 72d should be calculated according to a theoretical calculation or a computer simulation calculation.

The above structure shows the structure and distribution of 4 springs in a preferred embodiment, and for other embodiments, fewer or more springs may be included. Other embodiments of the spring arrangement can be found in fig. 1 and 2 and the corresponding embodiments.

And fig. 8 is a schematic view showing a connection manner of the resonance part and the cross beam in the present embodiment. Fig. 8 illustrates the vibration member 411, and the connection with the cross beam 43 is realized by two connecting beams 81C. The two connection beams 81C connect the resonance part 411 and the cross beam 43. The connecting beams 81C are also arranged in the Y direction, perpendicular to the axial direction X of the resonance member 411, and the two connecting beams 821C are symmetrical to each other along the center axis a-a of the cross beam 43. The symmetrically arranged connection beams can strongly limit the vibration of the resonant part 411 along the Y direction, and weakly limit the vibration of the resonant part 411 along other translational or rotational directions.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. A vibration module, disposed in an XY plane, comprising a resonant member disposed at a distal end of a cantilever beam, wherein: the vibration module also comprises an elastic limiting component, and the resonance component is connected with an external fixed component through the elastic limiting component and the cantilever beam; under resonance part is in the vibration state, the cantilever beam is the first restriction power that resonance part provided, elasticity stop part does resonance part provides the second restriction power, the position of action of the resultant of first restriction power and second restriction power with resonance part's barycenter coincidence, and the direction of action with resonance part's vibration direction is unanimous, through the adjustment cantilever beam's size and coefficient of elasticity, and elasticity stop part's coefficient of elasticity makes the position of action of the resultant of first restriction power and second restriction power with resonance part's barycenter coincidence, and the direction of action with resonance part's vibration direction is unanimous.

2. The vibration module according to claim 1, wherein the resonance member includes an electrode and is driven by an external driving electric field through the electrode, the driving electric field applies a third restriction force to the resonance member, and a resultant force of the first restriction force, the second restriction force, and the third restriction force acts at a position coinciding with a centroid of the resonance member and in a direction perpendicular to the XY plane.

3. A vibration module according to claim 1, wherein said elastic limiting member comprises at least one spring, one end of said spring is connected to said resonance member, and the other end of said spring is connected to said fixing member.

4. The vibration module according to claim 3, wherein the elastic limiting member comprises two springs disposed in the same plane, the axial direction of each spring is perpendicular to the vibration direction of the resonance member, and the axial directions of the two springs are disposed on the same straight line.

5. The vibration module according to claim 1, wherein the vibration state of the resonance member includes out-of-plane vibration in the Z-direction, and in-plane vibration in the XY-plane.

6. A gyroscope comprises a vibration module, a fixed component and a cantilever beam, wherein the vibration module is arranged in an XY plane and comprises a resonance component, one end of the cantilever beam is connected with the resonance component, and the other end of the cantilever beam is connected with the fixed component, and the gyroscope is characterized in that: the vibration module also comprises an elastic limiting component, and the resonance component is connected with the fixed component through the elastic limiting component and the cantilever beam; under resonance part is in the vibration state, the cantilever beam is the first restriction power that resonance part provided, elasticity stop part does resonance part provides the second restriction power, the position of action of the resultant of first restriction power and second restriction power with resonance part's barycenter coincidence, and the direction of action with resonance part's vibration direction is unanimous, through the adjustment cantilever beam's size and coefficient of elasticity, and elasticity stop part's coefficient of elasticity makes the position of action of the resultant of first restriction power and second restriction power with resonance part's barycenter coincidence, and the direction of action with resonance part's vibration direction is unanimous.

7. The gyroscope of claim 6, wherein the resonant section includes a first electrode, the fixed section includes a second electrode, the electrodes form a driving capacitance to apply a third confining force to the resonant section, and a resultant of the first confining force, the second confining force, and the third confining force acts at a position coinciding with a centroid of the resonant section and in a direction perpendicular to the XY-plane.

8. The gyroscope of claim 6, wherein the resilient limiting member comprises at least one spring having one end connected to the resonating member and the other end connected to the fixed member.

9. The gyroscope of claim 8, wherein the elastic limiting member comprises two springs disposed in the same plane, each spring has an axial direction perpendicular to a vibration direction of the resonance member, and the axial directions of the two springs are disposed on the same straight line.

10. The gyroscope of claim 6, wherein the vibration states of the resonant member include out-of-plane vibrations in the Z direction, and in-plane vibrations in the XY plane.