KR100363784B1 - Microgyrocrope - Google Patents

Abstract

The present invention relates to a micro gyroscope capable of minimizing a distortion phenomenon appearing when tuning a frequency by separately configuring an excitation vibration frame and a sensing vibration frame. The technical configuration of the present invention is a beam inside the outer frame 120. An inner frame 110 is installed through the elastic body 130, and an elastic body 230 having an excitation direction (X-axis direction) is installed at each corner of the outer frame 120, and the outer frame 120 is installed. The electrode 260 is provided to detect the excitation state from the difference in capacitance generated between the excitation drivers 250 and 250 ′ disposed between the combs 220.

Description

Micro Gyroscope {Microgyrocrope}

The present invention relates to a micro gyroscope that minimizes the distortion phenomenon that occurs when tuning the frequency by separately configuring the vibration frame and the sensing vibration frame in the gyroscope (Microgyrocrope) consisting of a microstructure, in particular, The inner frame is installed inside the outer frame via the sensing direction beam elastic body, and the outer frame installed through the sensing direction beam elastic body outside the inner frame is installed with an excitation elastic body to separate the vibration of the excitation and sensing mode. Accordingly, the present invention relates to a micro gyroscope that minimizes the phenomena generated during frequency tuning of the excitation direction and the sensing direction, and maximizes the performance of the microgyro.

In general, the angular velocity sensor device for detecting the angular velocity of an inertial body has been used as a key component for navigation devices in ships and aircrafts for a long time, and is currently used to detect hand shake of a car navigation device or a high magnification video camera. It is used in devices that compensate for this.

However, the conventional angular velocity sensing gyroscope used for military or aircraft can obtain precise performance because many complicated parts are manufactured through precision processing and assembly process, but the manufacturing cost is high, and the volume is enlarged to general industrial use. However, the situation is not applicable to consumer electronics.

Recently, a small gyroscope having a piezoelectric element attached to a triangular prism-shaped beam has been developed and used as a sensor for detecting hand shake of a small video camera. In addition, there has been developed a small gyroscope having an improved cylindrical beam structure to overcome the difficulties caused by the manufacturing of the gyroscope attached to the piezoelectric element as described above.

However, since both types of small gyroscopes are made of small parts that require precision machining, they are difficult to manufacture and costly. In particular, such gyroscopes have many Since it consists of mechanical parts, there is a problem that it is difficult to apply the integrated circuit.

On the other hand, the principle of such a gyroscope is that when the oscillating body is constantly vibrating in the first axial direction, or the rotating inertial body receives an input of the angular velocity by the rotation in the second axial direction perpendicular to the first axial direction, The rotational angular velocity is detected by detecting the Coriolis force occurring in the third axial direction orthogonal to the two axes.

At this time, balancing the force applied to the inertial body increases the accuracy of the angular velocity detection. In particular, in order to increase the linearity and bandwidth of a signal, a structure using a force balancing method is preferable.

In the configuration of a conventional micro gyroscope related to such a technique, as shown in FIG. 1, a plurality of combs 20 are arranged in the sensing direction (Y-axis direction) in a state in which the combs 20 are stowed inside the frame 10. A sensing direction (Y-axis direction) sensing electrode 40 fixed to and supported by the + and − electrode supports 30 and 30 ′ between each comb 20 is mutually constant between the combs 20. Is spaced apart from each other, the frame 10 intersects with the vibration structure 60 extending in the width direction through the sensing direction elastic body 50 that is spoken to the four places on both sides of the upper and lower sides, the vibration structure 60 Silver causes the excitation to operate by the application of the voltage of the excitation driver (70), wherein each corner portion of the vibration structure is made of a configuration in which the excitation elastic body 80 is coalesced.

The conventional gyroscope is a direction perpendicular to the plane of the gyroscope when the vibration structure 60 vibrates in the excitation mode (X-axis direction) by the application of an alternating voltage of the excitation driver 70 ( When the angular velocity input is entered in the Y-axis direction, a Coriolis force is generated in the sensing direction to move the internal structure of the frame 10 in the sensing direction, and this movement changes the capacitance of the sensing beam. In addition, the amount of angular velocity is measured by measuring the changed capacitance.

However, in such a case, the sensing and the vibration of vibration caused by separating the sensing directional elastic body 50 and the directional elastic body 80 respectively installed on the frame 10 of the gyroscope can be reduced, while the excitation and sensing Since the directional elastic bodies 80 and 50 are integrally installed in one frame 10, there is a disadvantage in that a phenomena occur in the two-way frequency tuning of excitation and sensing as shown in FIG.

In addition, in the micro gyroscope as described above, the excitation and sensing direction vibration transmitted to one frame 10 causes a negative effect on the sensitivity of the gyroscope, as well as poor linearity according to the angular velocity. As a result, there have been many problems such as a decrease in the resolution of the gyroscope and a shortening of the life of the gyroscope.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object thereof is that an inner frame is installed in a gyroscope outer frame via a sensing direction beam elastic body, and a sensing direction outside the inner frame. In the outer frame installed through the beam elastic body, the excitation direction elastic body is installed to separate the vibration of the excitation and sensing mode, thereby minimizing the phenomena generated during the frequency tuning of the excitation direction and the sensing direction. It is to provide a micro gyroscope that can further extend the life of the gyroscope while maximizing the resolution and sensitivity performance of the micro gyroscope.

1 is a plan view of a conventional micro gyroscope.

Figure 2 is a graph of the excitation and detection mode occurring during conventional frequency tuning.

3 is a schematic plan view of a micro gyroscope according to the present invention;

Figure 4 is an enlarged structural view of the main portion of the stopper provided on both sides of the inner frame of the present invention.

5 is a graph showing the excitation and detection mode generated during the frequency tuning of the present invention.

Figure 6 is a plan view of a micro gyroscope according to another embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

Gyroscope unit 110 Internal frame

120 ... outer frame 130 ... beam elastomer

140,160 electrode support 150 comb

170 sensing electrode 180 stopper

220 ... comb 230,270 ... with elastomer

250,250 '... Vibration driver 260 ... Electrode

The present invention as a technical configuration for achieving the above object, the inner frame is installed so as to have an inner side of the outer frame;

A comb that is installed on both sides of the inner frame and installed in a sensing direction (Y-axis direction);

A sensing direction sensing electrode disposed to be spaced apart from each other by the combs to be fixed to the upper and lower electrode supporting parts;

A beam elastic body installed between the inner frame and the outer frame to have a sensing direction;

An excitation elastic body installed in the corner portion of the outer frame so as to have an excitation direction (X-axis direction);

Combs installed on both sides of the outer frame; And

By providing a micro gyroscope, characterized in that it comprises a drive for the excitation actuated by the application of voltage.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 3 is a schematic plan view of the micro gyroscope according to the present invention, Figure 4 is an enlarged structural diagram of the main portion of the stopper installed on both sides of the inner frame of the present invention, the vibration structure in the gyroscope device 100 of the present invention is a Coriolis An inner frame 110 having a sensing unit, an outer frame 120 and an excitation driver 250 and 250 ′ installed on both sides of the outer frame 120.

The inner frame 110, which is an inner mass part of the gyroscope apparatus 100, detects the beam elastic body 130 integrally with the outer frame 120 at four inner, front, rear, and left and right sides of the outer frame 120. Axial direction) and as far as possible in parallel, wherein the inner frame 110, a plurality of combs 150 are installed in the Y-axis direction while the combs 150 on both sides therein, while each of the combs 150 ) Is fixed to the upper and lower electrode support parts 140 and 160 composed of + and − electrodes, and the sensing electrodes 170 are spaced at predetermined intervals so as to support the sensing direction (Y-axis direction). do.

The beam elastic body 130 installed at four positions between the outer and inner frames 120 and 110 which are the vibration structures has + and − electrode support parts 140 and 160 installed at both sides of the inner frame 110. When the voltage is applied, the inner frame is formed by the electrostatic force generated between the vertical sensing electrode 170 installed in the shape of the comb in the electrode support unit 140 and 160 and the combs 150 of the frame which is a vibration structure. When the 110 is excited, it is possible to minimize the ductility of the sensing direction, wherein the comb 150 of the inner frame 110 and the sensing direction sensing electrode of the + and − electrode supports 140 and 160 ( 170, the outer frame 120, which is communicated via the inner frame 110 and the beam elastic body 130, which is a vibration structure, can be detected from the difference in capacitance generated between the coriolis. Movement in the sensing direction (vertical direction) It acts as a deterrent.

Meanwhile, stoppers 180 as shown in FIGS. 3 and 4 are installed at the centers of both sides of the inner frame 110, and the combs 150 and the + and − electrode support parts 140 of the inner frame 110 are installed. The contact between the comb 150 and the sensing electrode 170 is prevented by the vibration generated between the sensing direction sensing electrodes 170 of the 160. In this case, the interval t of the stopper 180 is an internal frame. The distance between the comb 150 of the 110 and the sensing electrode 170 of the electrode support 140 and 160 is set to be equal to or less than a distance.

Subsequently, the outer frame 120 installed outside the inner frame 110 via the sensing direction beam elastic body 130 has an excitation direction (X-axis direction) through the elastic members 230 having respective corner portions. In such a state that it is possible to have a snow, a plurality of comb 220 is installed on both sides of the outer frame 120.

The comb 220 installed in the outer frame 120 fills a gap between the electrodes 260 formed in the excitation driver 250 or 250 ′ which is operated by the application of a voltage. The outer frame 120 is excited by an electrostatic force generated between the comb 220 of the outer frame 120 and the comb 260 formed on the excitation driver 250, 250 ′, or The excitation state can be detected from the difference in capacitance generated between the comb 220 of the outer frame and the electrodes 260 of the excitation drivers 250 and 250 ′.

At this time, the excitation driver 250, 250 'to have the outer frame 120 in the left and right, horizontal direction (X-axis direction) is disposed in parallel with the width direction of the outer frame 120, the excitation The plurality of electrodes 260 formed in the dragon drivers 250 and 250 ′ are disposed between the combs 220 of the outer frame 120.

On the other hand, Figure 5 is a graph of the excitation and detection mode generated during the frequency tuning of the present invention, the excitation elastic body 230 is composed of a plate elastic body, the excitation actuators 250, 250 'of the outer frame 120 When excited in the excitation mode by the application of + and − voltages, the ductility in the excitation mode is absorbed by the excitation elastic body 230, and thus the frequency tuning of the excitation direction and the detection direction can be almost eliminated. It is possible to minimize the phenomenon of Peering (Veering) generated at the time.

On the other hand, Figure 6 is a plan view of a micro gyroscope according to another embodiment of the present invention, it is integral with the rear of the excitation elastic body 230 which is installed in each corner of the outer frame 120 which is an oscillation frame Each of the separate excitation elastic body 270 is installed so as to minimize the amount of displacement in the excitation direction in the sensing end.

In such a case, after the vibration in the excitation direction is first absorbed by the elastic body 230, the vibration is absorbed again by the excitation elastic body 270 integrally installed at the rear thereof, so that the amount of displacement in the excitation direction can be minimized. Accordingly, by connecting the excitation elastic body 230, 270 consisting of a leaf spring in parallel with each other, it is easy to control the stiffness of the excitation elastic body.

Hereinafter, the operation of the micro gyroscope according to the present invention will be described.

As shown in Fig. 5, the inner frame 110, which is a vibration structure having a mass M, and the outer frame 120, which has two outer mass parts, which are vibration structures having a mass M / 2 on both sides thereof, have an excitation direction ( The elastic body 230 in the X-axis direction) and the beam elastic body 130 are separated in the sensing direction (Y-axis direction), respectively. In the vibration system as described above, the external force f for exciting the vibration structure in the X-axis direction can be expressed by the following equation.

At this time, the displacement (X) and the speed (V) of the X-axis motion of the vibration structure can be expressed as follows.

In the above formula Is the displacement in the X axis direction, Is the velocity of the vibrating structure in the X axis direction.

The displacement generated in the Y-axis direction by the Coriolis force generated in proportion to the input angular velocity,

Is calculated.

Where

And For the X-axis and Y-axis directions Constant Is the input angular velocity.

therefore, The displacement angular velocity of the inertial body can be measured by detecting the displacement

In the gyroscope device 100 of the present invention, the mass M corresponds to M and M / 2, which are the mass of the vibration structure, respectively, and when an AC voltage corresponding to the natural frequency is applied to the excitation drivers 250 and 250 ′, The electrostatic force between the combs causes vibration in the X-axis direction.

The constant power of the excitation drivers 250 and 250 ′ by the constant power may be expressed by the following equation.

In the above formula Is the driving force, ε is the dielectric constant of air, Is the thickness of the comb, Is the number of pairs of combs, Is the driving voltage, Is the distance between the combs.

The vibration structure receiving the driving force as described above is to vibrate according to the natural frequency, in order to maintain the vibration of the natural frequency by generating a voltage that satisfies the unstable oscillation control condition based on the detected motion 250 To operate 250 '.

When the rotational angular velocity is input to the oscillating oscillation structure, the oscillation structure vibrates in the X-axis direction and is simultaneously displaced in the Y-axis direction. This displacement causes a change in capacitance formed between the sensing electrodes 170 of the + and − electrode supports 140 and 160 and the combs 150 of the inner frame 110, which are vibration structures.

The sensing electrode 170 is composed of a positive electrode and a negative electrode through the electrode support portions 140 and 160 as shown in FIG. 3, and the change in the capacitance of the positive electrode and the negative electrode occurs opposite to each other. The displacement of the vibrating structure in the Y-axis direction can be detected by calculating the difference in capacitance generated from the cathode sensing electrode.

The difference in capacitance between the two electrodes Is calculated by the following equation.

Where Is the number of pairs of sensing electrodes 170, Is the dielectric constant of air, Is the length of the sensing electrode, t is the thickness of the comb 150 of the inner frame 110 and the sensing electrode 170 of the electrode support 140, 160 that is a vibrating structure facing each other, Is the gap between the sensing electrode and the vibrating structure.

When a general circuit for detecting a change in capacitance is used, it is possible to detect a voltage signal proportional to the change in capacitance, and as a result, an angular velocity signal can be detected.

On the other hand, as a common important factor in determining the performance of the gyroscope, it is necessary to match the natural frequency in the X-axis direction and the Y-axis direction in order to maximize the displacement in the Y-axis direction by the Coriolis force.

In the present invention, since the stiffness in the Y-axis direction is affected by the electrostatic force generated by the sensing electrode 170, it is possible to adjust the natural frequency by using the electrostatic force, the natural frequency in the Y-axis direction is It is expressed by the formula

Where Is the constant of the beam elastomer, Is the elastic constant generated by the electrostatic force between the sensing electrode and the comb which is the vibration structure.

Can be expressed as

In the above formula Is a bias voltage applied to the sensing electrode.

The drift voltage may be adjusted to match the natural frequency in the Y-axis direction with the natural frequency in the X-axis direction.

In this case, if the drift voltage of the sensing electrode is changed in the same manner as above, the output of the gyroscope is changed. Therefore, the drift voltage of the sensing electrode is fixed by another method, and an accurate adjustment can be performed by using a separate natural frequency adjusting electrode. It can be.

Thus, when excited in the excitation mode by the application of the + and − voltages of the excitation drivers 250 and 250 ', the ductility in the excitation mode by the excitation elastic body 230 is absorbed and the excitation elastic body 270 behind it. ), The ductility caused by the vibration is absorbed again, and thus the ductility of the sensing direction becomes non-combustible so that the displacement can be almost eliminated, thus minimizing the phenomena generated during the frequency tuning of the excitation direction and the sensing direction. It is.

According to the micro gyroscope according to the present invention as described above, the inner frame is installed inside the gyroscope outer frame via the sensing direction beam elastic body, the outer frame is installed on the outer side of the inner frame, the excitation direction elastic body By separating the vibration of the excitation and sensing mode, it is possible to minimize the phenomena generated during the frequency tuning of the excitation direction and the detection direction, and to maximize the resolution and sensitivity performance of the micro gyroscope, the gyroscope There is an excellent effect that can further extend the life of.

While the invention has been shown and described with respect to specific embodiments thereof, it will be appreciated that various changes and modifications can be made in the art without departing from the spirit or scope of the invention as set forth in the following claims. Those of ordinary skill will want to know easily.

Claims (6)

delete An inner frame 110 installed to be integrally provided inside the outer frame 120; A comb 150 which is installed on both sides of the inner frame 110 and installed in a sensing direction; A sensing direction sensing electrode 170 disposed between the combs 150 at predetermined intervals and fixedly supported by the upper and lower electrode support parts 140 and 160; A beam elastic body 130 installed between the inner frame 110 and the outer frame 120 to have a sensing direction; A first exciting elastic body 230 installed in the outer frame 120 so as to have an exciting direction (X-axis direction); A comb 220 installed on both sides of the outer frame; And Excitation drivers 250 and 250 ′ actuated by application of a voltage, A stopper 180 is installed in the inner frame 110 to prevent the comb 150 of the inner frame 110 and the sensing direction sensing electrode 170 of the electrode support 140 or 160 from contacting each other. Micro gyroscope, characterized in that. The distance t of the stopper 180 is equal to or less than a separation distance between the comb 150 of the inner frame 110 and the sensing electrode 170 of the electrode support 140 or 160. Micro gyroscope, characterized in that set. The gyroscope according to claim 2, wherein the elastic body (230) provided in the outer frame (120) is composed of a box-shaped leaf spring. According to claim 2, in the rear of the excitation elastic body 230 which is installed in the outer frame 120 so as to have the excitation direction (X-axis direction) is possible, a separate excitation elastic body 270 is speeched to the excitation elastic body ( Micro gyroscope, characterized in that it is installed to absorb the vibration of 230 again. 6. The gyroscope according to claim 5, wherein the other excitation elastic body (270) behind the excitation elastic body (230) which is installed in the outer frame (120) is composed of a box-shaped leaf spring.