JPH0868636A - Apparatus for detecting both acceleration and angular velocity - Google Patents

Abstract

PURPOSE: To obtain an apparatus by which both acceleration and angular velocity can be detected with sufficient responsivity. CONSTITUTION: Excitation means 141 to 143 which are used to vibrate a vibrator 130 having a mass (m) to respective axial directions and force detection means 15a to 153 which are used to detect forces, in the respective axial directions, acting on the vibrator 130 are installed. The detected forces in the respective axial directions are separated into forces (f) generated by an acceleration and into Coriolis' forces F generated by an angular velocity. Acceleration arithmetic means 171 to 173 output components αx, αy, αz in the respective axial directions of the acceleration by using an operation expression of f=m.α on the basis of the respective forces (f). Angular-velocity axial arithmetic means 181 to 183 output angular velocities ωx, ωy, ωz around respective axes by using an operation expression of F=2m.v.ω[where (v) represents an instantaneous speed regarding the vibration direction of the vibrator] on the basis of the respective separated Coriolis' forces F.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting both acceleration and angular velocity, and more particularly to a device for detecting acceleration and angular velocity based on a force acting on a vibrator.

[0002]

2. Description of the Related Art In the case of detecting a physical quantity such as acceleration or angular velocity, conventionally, an acceleration detecting device is generally used to detect acceleration, and an angular velocity detecting device is generally used to detect angular velocity. As far as the applicant of the present application is aware, a device capable of detecting both acceleration and angular velocity has not been put into practical use at this stage. Further, conventionally, a one-dimensional acceleration detection device that detects acceleration in a specific one-axis direction and a one-dimensional angular velocity detection device that detects an angular velocity around a specific one-axis are general, and two-dimensional or three-dimensional coordinate axes In the case of detecting these physical quantities for each component, it is common to arrange an independent detection device for each coordinate axis.

However, in recent years, there has been an increasing demand in the automobile industry, machine industry and the like for a detection device capable of accurately detecting a physical quantity such as acceleration or angular velocity. In particular, there is a demand for a small-sized detection device capable of detecting these physical quantities for each of the two-dimensional or three-dimensional coordinate axis components. In order to meet such demand, the same inventor of the present application uses a single detection device to determine acceleration in each coordinate axis direction in a three-dimensional coordinate system and angular velocity about an angular coordinate axis.
Techniques for detecting each independently have been proposed. That is, international application PCT / JP93 based on the Patent Cooperation Treaty
/ 00390 or patent application filed by the same applicant as the present application dated July 21, 1994 (reference number: A0606
The specification of 2) discloses a novel detection device capable of detecting acceleration and angular velocity for each coordinate axis component based on the force acting on the vibrator. The angular velocity detection principle in this device utilizes the Coriolis force. That is, when the oscillator is vibrated in the Y-axis direction while the angular velocity ωx about the X-axis is acting on the oscillator, the oscillator is excited by the principle that the Coriolis force acts in the Z-axis direction. The device detects the Coriolis force acting in the Z-axis direction while vibrating in the Y-axis direction by the means, and based on this Coriolis force, the angular velocity ω about the X-axis.
x is indirectly obtained.

[0004]

The above-described novel detection device is a relatively small device, but it has X-axis, Y-axis, and Z-axis.
It is a useful device that can detect six physical quantities, namely, acceleration in the axial direction and velocities around these axes. However, with this device, even for the detection of acceleration,
In order to detect the angular velocity, it is necessary to detect the force acting on the vibrator. That is, on the one hand, the acceleration applied from the outside is detected by detecting the force acting on the vibrator while the vibrator is kept stationary, and on the other hand,
The angular velocity given from the outside is detected by detecting the Coriolis force acting on the vibrator while the vibrator is vibrating in the predetermined direction. Therefore, when the acceleration is detected, the vibrator must be kept stationary, and when the angular velocity is detected, the vibrator must be kept in the vibrating state.

When such a detecting device is mounted on an automobile or an industrial machine for use, it is usually required to detect the acceleration and the angular velocity, which change moment by moment, in real time. In order to detect the acceleration and the angular velocity in real time by using the above-described detection device, the operation of performing the acceleration detection while keeping the vibrator in a stationary state and the operation of detecting the angular velocity while keeping the vibrator in the vibrating state are performed. It is necessary to alternately perform the operation to be performed and the operation to be performed. However,
There is a limit to the mechanical responsiveness of the vibrator, and it takes a certain amount of time to vibrate the vibrator in a stationary state or to stop the vibrator in a vibrating state. Therefore, when the operation of detecting the acceleration and the angular velocity in real time is performed, there arises a problem that sufficient responsiveness cannot be obtained.

Therefore, an object of the present invention is to provide a detection device capable of detecting both acceleration and angular velocity with sufficient responsiveness.

[0007]

[Means for Solving the Problems]

(1) A first aspect of the present invention is a device for detecting acceleration in the first axis direction and angular velocity about a second axis in a three-dimensional coordinate system, and a vibrator having a mass and the vibrator. , In the third axis direction in the three-dimensional coordinate system, excitation means for vibrating at a sufficiently high frequency that can be identified with respect to the frequencies of the acceleration and angular velocity to be detected, and in the first axis direction applied to the vibrator Force detection means for detecting the force of
Regarding the detection signal obtained by the force detection means, a signal separation means for separating a bias component and an amplitude component, an acceleration calculation means for obtaining acceleration in the first axial direction based on the bias component, and an amplitude component based on the amplitude component, And an angular velocity calculation means for obtaining an angular velocity about the second axis.

(2) A second aspect of the present invention is a device for detecting acceleration in each axial direction of a first axis, a second axis and a third axis and an angular velocity around each axis in a three-dimensional coordinate system. And a first excitation means for vibrating the oscillator in the first axial direction at a frequency sufficiently high to be discriminable from the frequencies of the acceleration and angular velocity to be detected. , A second excitation means for vibrating the oscillator in the second axis direction at a sufficiently high frequency that can be identified with respect to the frequencies of the acceleration and the angular velocity to be detected, and the oscillator for the third axis. Direction, a third excitation means for vibrating at a sufficiently high frequency that can be identified with respect to the frequency of the acceleration and angular velocity to be detected, and a first force detecting means for detecting a force applied to the vibrator in the first axial direction. Force detecting means and the second axial direction applied to the vibrator. A second force detecting means for detecting the force, and a third force detecting means for detecting the force applied to the vibrator in the third axial direction.
Of the force detection means, the first detection signal obtained by the first force detection means, the first signal separation means for separating the bias component and the amplitude component from each other, and the second signal detection means obtained by the second force detection means. The second signal separating unit that separates the bias component and the amplitude component from the detection signal No. 3 and the third signal that separates the bias component and the amplitude component from the third detection signal obtained by the third force detecting unit. A second acceleration calculation means for obtaining acceleration in the first axial direction based on the signal separation means, a bias component for the first detection signal, and a second acceleration calculation means for determining the acceleration in the second axial direction. Second acceleration calculating means for obtaining the acceleration in the axial direction of, and third acceleration calculating means for obtaining the third acceleration in the axial direction based on the bias component for the third detection signal, and second exciting means. A first angular velocity calculation means for driving the oscillator to vibrate in the second axial direction, and for obtaining the angular velocity about the third axis based on the amplitude component of the first detection signal obtained in this state; A second excitation means is driven to vibrate the vibrator in the third axis direction, and the angular velocity about the first axis is obtained based on the amplitude component of the second detection signal obtained in this state. Of the second axis around the second axis based on the amplitude component of the third detection signal obtained in this state by driving the angular velocity calculation means and the first excitation means to vibrate the vibrator in the first axis direction. And a third angular velocity calculating means for determining the angular velocity of.

(3) A third aspect of the present invention is a device for detecting acceleration in each axial direction of a first axis, a second axis and a third axis and an angular velocity around each axis in a three-dimensional coordinate system. And a first excitation means for vibrating the oscillator in the first axis direction at a frequency sufficiently high to be discriminable from the frequencies of the acceleration and angular velocity to be detected. , A second exciting means for vibrating the oscillator in the third axis direction at a sufficiently high frequency that can be discriminated from the frequencies of the acceleration and the angular velocity to be detected, and the first axis added to the oscillator. First force detecting means for detecting a force in a direction, second force detecting means for detecting a force in a second axial direction applied to the vibrator, and force in a third axial direction applied to the vibrator And a first force detection means obtained by the first force detection means. Regarding the output signal, the first signal separation means for separating the bias component and the amplitude component, and the second detection signal obtained by the second force detection means,
A second signal separating unit that separates the bias component and the amplitude component, and a third signal separating unit that separates the bias component and the amplitude component from the third detection signal obtained by the third force detecting unit.
Signal separation means, first acceleration calculation means for obtaining acceleration in the first axial direction based on the bias component for the first detection signal, and the first acceleration calculation means for determining the acceleration in the second axial direction based on the bias component for the second detection signal. Second acceleration calculating means for obtaining the second axial acceleration, third acceleration calculating means for obtaining the third axial acceleration based on the bias component for the third detection signal, and third excitation First angular velocity calculation means for driving the means to vibrate the vibrator in the third axis direction, and obtain the angular velocity about the second axis based on the amplitude component of the first detection signal obtained in this state. And the first
Driving the exciting means to vibrate the vibrator in the first axis direction, and based on the amplitude component of the second detection signal obtained in this state, the angular velocity about the third axis is obtained, and Drive the excitation means of the
Second angular velocity calculating means for obtaining an angular velocity around the first axis based on the amplitude component of the second detection signal obtained in the state of being vibrated in the axial direction.

(4) According to a fourth aspect of the present invention, the acceleration in the first axial direction and the angular velocity about the first axis in the three-dimensional coordinate system, and the acceleration in the second axial direction and the rotation about the second axis. In the device for detecting the angular velocity and the An exciting means for vibrating at a sufficiently high frequency, a first force detecting means for detecting a force in the first axial direction applied to the vibrator, and a force in a second axial direction applied to the vibrator. The second force detecting means, the first signal separating means for separating the bias component and the amplitude component of the first detection signal obtained by the first force detecting means, and the second force detecting means are obtained. Regarding the second detection signal, the bias component and Regarding the second signal separation means for separating the width component, the first acceleration calculation means for obtaining the acceleration in the first axial direction based on the bias component for the first detection signal, and the second detection signal Second acceleration calculating means for obtaining an acceleration in the second axial direction based on the bias component of the first angular velocity, and a first angular velocity for obtaining an angular velocity around the second axis based on the amplitude component of the first detection signal. The calculation means and the second angular velocity calculation means for obtaining the angular velocity around the first axis based on the amplitude component of the second detection signal are provided.

(5) A fifth aspect of the present invention relates to the above-mentioned first aspect.
In the apparatus according to the fourth to fourth aspects, the signal separating means extracts each inflection point of the detection signal and averages the signal values of the two inflection points at an intermediate position on the time axis of two adjacent inflection points. Then, a reference point having a signal value obtained by is obtained, and the signal obtained by connecting the obtained reference points is used as a bias component,
A signal corresponding to the difference between the detection signal and the bias component is used as the amplitude component.

(6) A sixth aspect of the present invention is based on the above first aspect.
In the device according to the fourth to fourth aspects, the acceleration calculation means applies the calculation formula f = m · α to calculate the acceleration α based on the detected bias component f of the force and the mass m of the vibrator. It's something I asked for.

(7) A seventh aspect of the present invention relates to the above-mentioned first aspect.
In the device according to the fourth to fourth aspects, the angular velocity calculation means is based on the detected amplitude component F of the force, the mass m of the vibrator, and the instantaneous speed v of the vibrator estimated from the operating state of the excitation means. Then, the angular velocity ω is obtained by applying the arithmetic expression F = 2m · v · ω.

[0014]

[Operation] In the detection device according to the present invention, the force acting on the vibrator is used for both the acceleration detection and the angular velocity detection. According to the basic principle of the detection operation in this detection device, in order to detect the acceleration, the vibrator is kept stationary,
The force acting on the vibrator at that time may be detected, and the angular velocity may be detected by keeping the vibrator in a vibrating state and detecting the force acting on the vibrator at that time. Based on such a basic principle, the inventor of the present application initially assumes that the acceleration detection with the oscillator in a stationary state and the angular velocity detection with the oscillator in a vibrating state are independently performed. Was there.

However, the inventor of the present application has found that it is possible to simultaneously detect acceleration and angular velocity. Now, for example, the acceleration in a certain axis direction,
It is assumed that the angular velocity about a certain axis is acting at the same time, and the acceleration and the angular velocity have a property of exerting a force in the same direction on a vibrator vibrating in a predetermined direction. In this case, the force acting on the oscillator is a combined force of the component caused by acceleration and the component caused by angular velocity. If this combined force can be separated into a component due to acceleration and a component due to angular velocity,
Simultaneous detection of acceleration and angular velocity is possible.

Such separation is possible when the vibration frequency of the vibrator is sufficiently high with respect to the frequencies of the acceleration and the angular velocity to be detected. That is, under such conditions, the component due to acceleration is combined as a bias component, and the component due to angular velocity is combined as an amplitude component. Therefore, by separating the obtained combined force into a bias component and an amplitude component, it is possible to independently obtain a component caused by acceleration and a component caused by angular velocity.

[0017]

Example §1. Basic Principle of Detecting Angular Velocity and Acceleration First, the basic principle of angular velocity detection in the detection device according to the present invention will be described. With the device according to the present invention, it is possible to detect angular velocities around two or three axes. Here, first, the principle of uniaxial angular velocity detection will be briefly described. Figure 1 shows the magazine "THE INVENTION", vo
It is a figure which shows the basic principle of the angular velocity detection apparatus currently disclosed by 60 pages of l.90, No.3 (1993). Now, prepare a prismatic vibrator 110, and set X,
Consider an XYZ three-dimensional coordinate system that defines Y and Z axes. In such a system, it is known that the following phenomenon occurs when the oscillator 110 makes a rotational motion at an angular velocity ω with the Z axis as the axis of rotation. That is, this oscillator 1
When a vibration U that reciprocates 10 in the X-axis direction is applied, a Coriolis force F is generated in the Y-axis direction. In other words,
When the vibrator 110 is vibrated along the X axis in the figure and the vibrator 110 is rotated about the Z axis, Y
Coriolis force F is generated in the axial direction. This phenomenon is a mechanical phenomenon that has long been known as a Foucault pendulum, and the generated Coriolis force F is represented by F = 2m · v · ω. Here, m is the mass of the vibrator 110, v is the instantaneous speed of the vibration of the vibrator 110, and ω is the vibrator 1
10 instantaneous angular velocities.

The uniaxial angular velocity detecting device disclosed in the above-mentioned magazine utilizes this phenomenon to detect the angular velocity ω. That is, as shown in FIG.
A first piezoelectric element 111 is provided on the first surface of
The second piezoelectric element 112 is provided on the second surface orthogonal to the surface of
Each can be attached. As the piezoelectric elements 111 and 112, plate-shaped elements made of piezo electric ceramic are used. The piezoelectric element 111 is used to apply the vibration U to the vibrator 110, and the piezoelectric element 112 is used to detect the generated Coriolis force F. That is, when an AC voltage is applied to the piezoelectric element 111, the piezoelectric element 111 repeatedly expands and contracts and vibrates in the X-axis direction. This vibration U is transmitted to the vibrator 110,
The vibrator 110 vibrates in the X-axis direction. As described above, in the state where the vibration U is applied to the vibrator 110, the vibrator 1
When 10 itself rotates about the Z axis at the angular velocity ω,
Due to the phenomenon described above, the Coriolis force F is generated in the Y-axis direction. Since this Coriolis force F acts in the thickness direction of the piezoelectric element 112, the Coriolis force F acts on both sides of the piezoelectric element 112.
A voltage V proportional to is generated. Therefore, by measuring this voltage V, the angular velocity ω can be detected.

The above-mentioned conventional angular velocity detecting device is for detecting the angular velocity around the Z-axis, and cannot detect the angular velocity around the X-axis or the Y-axis. In the detection device according to the present invention, as shown in FIG. 2, for a predetermined object 120, an angular velocity ωx about the X axis, an angular velocity ωy about the Y axis, and an angular velocity ωz about the Z axis in the XYZ three-dimensional coordinate system, respectively. Can be independently detected. The basic principle will be described with reference to FIGS. Now, it is assumed that the vibrator 130 is placed at the origin position of the XYZ three-dimensional coordinate system. In order to detect the angular velocity ωx of the vibrator 130 about the X axis, as shown in FIG. 3, when a vibration Uz in the Z axis direction is applied to the vibrator 130, the Coriolis force Fy generated in the Y axis direction is generated. Should be measured. The Coriolis force Fy has a value proportional to the angular velocity ωx. In addition, the angular velocity ωy about the Y axis of the vibrator 130
To detect the vibration, as shown in FIG.
When the vibration Ux in the X-axis direction is applied to, the Coriolis force Fz generated in the Z-axis direction may be measured. Coriolis force Fz
Is a value proportional to the angular velocity ωy. Furthermore, this oscillator 1
To detect the angular velocity ωz about the Z axis of 30, as shown in FIG. 5, when vibration Yy in the Y axis direction is applied to the vibrator 130, it is necessary to measure the Coriolis force Fx generated in the X axis direction. Good. The Coriolis force Fx has a value proportional to the angular velocity ωz.

After all, in order to detect the angular velocity ωx about the X axis, the angular velocity ωy about the Y axis, and the angular velocity ωz about the Z axis in the XYZ three-dimensional coordinate system, as shown in FIG. X that gives vibration Ux in the X-axis direction
Axial excitation means 141, Y which gives vibration Uy in the Y-axis direction
Axial direction excitation means 142, Z for giving vibration Uz in the Z-axis direction
Each of the axial excitation means 143, an X-axis direction force detection means 151 for detecting the X-axis direction Coriolis force Fx acting on the vibrator 130, and a Y-axis direction force detection means for detecting the Y-axis direction Coriolis force Fy. 152, Coriolis force F in the Z-axis direction
Each of Z-axis direction force detection means 153 for detecting z,
Will be prepared.

On the other hand, the principle of detecting the acceleration is simpler. That is, when an acceleration α in a predetermined direction acts on a vibrator in a stationary state (functioning as a weight having a simple mass m), a force f of f = m · α acts in the same direction as the acceleration α. It will be. Therefore, by detecting the forces fx, fy, and fz acting on the vibrator 130 in the stationary state in the respective axial directions, the accelerations αx, αy, and αz in the respective axial directions can be detected by the calculation using the mass m. .

After all, in order to detect the acceleration αx in the X-axis direction, the acceleration αy in the Y-axis direction, and the acceleration αz in the Z-axis direction in the XYZ three-dimensional coordinate system, as shown in FIG. X-axis direction force detecting means 151 for detecting the acting force fx in the X-axis direction, Y-axis direction detecting means 152 for detecting the force fy in the Y-axis direction, Z-axis direction force detecting for detecting the force fz in the Z-axis direction. It suffices to prepare each of the means 153.

FIG. 6 shows the components of the three-dimensional angular velocity detecting device as a block diagram and FIG. 7 shows the components of the three-dimensional acceleration detecting device as a block diagram. It can be seen that the former configuration includes the latter configuration. That is, in addition to the acceleration detecting device shown in FIG.
By adding 2, 143, the angular velocity detecting device shown in FIG. 6 can be obtained, and the angular velocity detecting device shown in FIG. 6 also functions as the acceleration detecting device shown in FIG. 7.

However, since both the angular velocity and the acceleration are detected in the form of a force acting in each axial direction, if both the angular velocity and the acceleration are detected by a single detecting device, the detected force is Both the angular velocity component and the acceleration component will be included. As described above, the force due to the angular velocity is a Coriolis force (having a magnitude of F = 2 m · v · ω) that is generated only when the vibrator is vibrated in a predetermined direction, and in the present specification, This will be indicated by a capital "F". In FIG. 6, each force detecting means 1
Fx, F which are the detection targets of 51, 152, 153
Both y and Fz are Coriolis forces generated due to the angular velocity. On the other hand, the force due to acceleration is a force (f = m · α) that is generated irrespective of the vibration of the vibrator, and will be indicated by a lower case “f” in this specification. In FIG. 7, fx, fy, and fz, which are the detection targets of the force detection units 151, 152, and 153, are forces generated due to acceleration. When both the angular velocity and the acceleration are acting on the oscillator 130, the Coriolis forces Fx, Fy, Fz caused by the angular velocity and the force fx caused by the acceleration are applied to the force detection means 151, 152, 153. , F
The combined force with y and fz will be detected. The problem to be solved by the present invention is how to separately detect the Coriolis force F caused by the angular velocity and the force f caused by the acceleration in such a situation.

§2. Specific tests suitable for practicing the present invention
Structure of Output Device The basic configuration of the detection device according to the present invention is as shown in the block diagram of FIG. 6, and the present invention is applicable to any detection device having such a configuration However, it is applicable. Regarding the specific structure of the detection device having the configuration shown in the block diagram of FIG. 6, the international application PCT / JP93 / 00390 specification based on the above-mentioned Patent Cooperation Treaty and the present application dated July 21, 1994 In the specification of the patent application (reference number: A06062) by the same applicant as
Various embodiments are disclosed. The present invention does not relate to a specific structure of such a detection device, but relates to signal processing of a detection signal obtained from such a detection device. Therefore, here, only an example of a specific structure of such a detection device will be described as a reference. Of course, the technical scope of the present invention is not limited to the specific structure described here.

FIG. 8 is a perspective view of this specific detecting device as seen obliquely from above, and FIG. 9 is a perspective view of this specific detecting device as seen from obliquely below. This detection device includes 12 upper electrodes A1 to A8 and E1 to E4 on the upper surface of a disk-shaped piezoelectric element 10.
And one lower electrode B is formed on the lower surface. Here, for convenience of description, the origin O of the XYZ three-dimensional coordinate system is defined at the center position of the upper surface of the disk-shaped piezoelectric element 10, and the X axis and the Y axis are defined in the direction along the upper surface of the piezoelectric element 10. , Z axis is defined as a direction that is vertically upward with respect to the upper surface. Therefore, the upper surface of the piezoelectric element 10 is included in the XY plane.

The structural characteristic of the piezoelectric element 10 is that an annular groove 15 is formed in the lower surface as shown in FIG. In this embodiment, the annular groove 15 is circular so as to surround the origin O. The lower electrode B is a single electrode layer and is formed on the entire lower surface of the piezoelectric element 10 including the inside of the annular groove 15. On the other hand, each of the twelve upper electrodes A1 to A8 and E1 to E4 has a strip shape along an arc centered on the origin O, as clearly shown in the top view of FIG. The shape is line-symmetric with respect to the axis or the Y-axis.

The structure of this detection device will become more apparent with reference to FIG. FIG. 11 shows this detection device as XZ.
It is the sectional side view cut by the plane. Piezoelectric element 10 annular groove 1
The portion where 5 is formed is thinner than other portions and has flexibility. Here, a portion of the piezoelectric element 10 located above the annular groove 15 is referred to as a flexible portion 12, and a central portion surrounded by the flexible portion 12 is referred to as a central portion 11 and the flexible portion 12 is referred to. The portion located on the outer periphery will be referred to as the peripheral portion 13. The relative positional relationship of these three parts is clearly shown in the bottom view of FIG. That is, the flexible portion 12 is formed in the portion where the annular groove 15 is formed around the central portion 11, and the peripheral portion 13 is formed around the flexible portion 12.

Here, for example, when only the peripheral portion 13 is fixed to the detecting device casing and the entire detecting device casing is shaken, a force due to the acceleration acts on the central portion 11 due to its mass,
This force causes the flexible portion 12 to bend. That is, the central portion 11 is in a state of being supported from the periphery by the flexible portion 12 having flexibility, and the X-axis, Y-axis
It is possible to cause some displacement in the axial and Z-axis directions. After all, the central portion 11 in this detection device functions as the vibrator 130 having the mass in the detection device shown in FIG. In the detection device shown in FIG.
30 in addition to the excitation means 141, 142, 14 in each axial direction
3 and force detection means 151, 152, 153 in each axial direction are required. In this specific detection device, the excitation means 14
1, 142, 143 are composed of the upper electrodes E1 to E4, the lower electrode B, and the piezoelectric element 10 sandwiched between them, and force detecting means 151, 152, 153.
Is composed of the upper electrodes A1 to A8, the lower electrode B, and the piezoelectric element 10 sandwiched therebetween.

First, in order to explain that the excitation means and the force detection means can be constituted by the upper and lower electrodes and the piezoelectric element 10 sandwiched between them, first, the piezoelectric element 10 will be described.
Check the basic properties of. Generally, a piezoelectric element causes a polarization phenomenon due to the action of mechanical stress. That is, when a stress is applied in a certain specific direction, one has a property that positive charge is generated and the other is negative charge. In the detection device of this embodiment, as the piezoelectric element 10, piezoelectric ceramics having a polarization characteristic as shown in FIG. 13 is used. That is, as shown in FIG. 13A, when a force extending in the XY plane is applied, positive charges are generated on the upper electrode A side and negative charges are generated on the lower electrode B side. On the contrary, as shown in FIG. 13 (b), when a force in the contracting direction along the XY plane acts, negative charge is applied to the upper electrode A side and positive charge is applied to the lower electrode B side. , And have polarization characteristics that occur respectively.
On the contrary, when a predetermined voltage is applied to the upper and lower electrodes, mechanical stress acts inside the piezoelectric element 10. That is, as shown in FIG. 13 (a), when a voltage is applied so that positive charge is applied to the upper electrode A side and negative charge is applied to the lower electrode B side, a force in a direction extending along the XY plane is obtained. As shown in FIG. 13 (b), when a voltage is applied to give a negative charge to the upper electrode A side and a positive charge to the lower electrode B side, the direction shrinks along the XY plane. The power of is generated.

The specific detecting device described here constitutes each exciting means and each force detecting means by utilizing such a property of the piezoelectric element. That is, each excitation means is configured by utilizing the property that stress can be generated inside the piezoelectric element by applying a voltage to the upper and lower electrodes, and when stress acts inside the piezoelectric element, electric charge is applied to the upper and lower electrodes. Each force detecting means is configured by utilizing the property of occurrence of. The configuration and operation of each of these means will be described below.

<X-axis direction excitation means> Of the constituent elements shown in FIG. 6, the X-axis direction excitation means 141 includes upper electrodes E1 and E.
2, a part of the lower electrode B facing this, a part of the piezoelectric element 10 sandwiched between them, and an alternating current supply means described later. Now, while maintaining the lower electrode B at the reference potential, a positive voltage is applied to the upper electrode E1,
Consider a case where a negative voltage is applied to the upper electrode E2. Then, as shown in the side cross-sectional view of FIG. 14, stress is generated in the piezoelectric element below the electrode E1 in a direction extending in the left and right directions in the drawing, and
A stress in the direction of contracting to the left and right in the figure is generated in the piezoelectric element below 2 (see the polarization characteristics in FIG. 13). Therefore, the piezoelectric element 1
As a whole, 0 will be deformed as shown in FIG. 14, and the center of gravity P of the central portion 11 will be displaced by Dx in the X-axis direction. Here, the polarities of the voltages applied to the upper electrodes E1 and E2 are reversed, and a negative voltage is applied to the upper electrode E1,
When a positive voltage is applied to the upper electrode E2, contrary to FIG. 14,
The piezoelectric element under the electrode E1 is stressed in a direction contracting to the left and right in the figure, and the piezoelectric element under the electrode E2 is stressed in a direction extending in the left and right in the figure, and as a result, the center of gravity P of the center portion 11 is generated. Is
It will be displaced by -Dx in the X-axis direction.

Therefore, the first AC voltage is applied between the lower electrode B and the upper electrode E1, and the phase opposite to the first AC voltage is applied between the lower electrode B and the upper electrode E2. If such a second AC voltage is applied, the center of gravity P will alternately cause a displacement of Dx and a displacement of −Dx along the X-axis direction, and the center portion 11 will be aligned with the X-axis. It will vibrate along. As already mentioned, the central part 1
1 corresponds to the vibrator 130 in the components shown in FIG. Therefore, it becomes possible to apply the vibration Ux in the X-axis direction to the vibrator 130 by applying the AC voltage described above. The frequency of this vibration Ux can be controlled by the frequency of the applied AC voltage.
The amplitude of x can be controlled by the amplitude value of the applied AC voltage. After all, the upper electrodes E1 and E2, the lower electrode B, the piezoelectric element 10, and a means for supplying an AC voltage (not shown) constitute the X-axis direction excitation means 141 shown in FIG.

<Y-axis direction excitation means> Of the components shown in FIG. 6, the Y-axis direction excitation means 142 is the upper electrodes E3, E.
4, a part of the lower electrode B facing this, a part of the piezoelectric element 10 sandwiched between them, and an AC supply means (not shown). The operating principle is exactly the same as the operating principle of the X-axis direction excitation means 141 described above. That is, as shown in the top view of FIG. 10, the upper electrodes E1 and E2 are arranged on the X axis, whereas the upper electrodes E3 and E4 are arranged on the Y axis.
Therefore, the upper electrodes E3 and E4 can be oscillated by the same principle that the central portion 11 (vibrator) can be vibrated in the X-axis direction by supplying the alternating voltages whose phases are inverted to each other to the upper electrodes E1 and E2. The central portion 11 (vibrator) can be vibrated in the Y-axis direction by supplying AC voltages whose phases are reversed to each other.

That is, by applying the above-mentioned AC voltage, it is possible to give the vibrator 130 a vibration Uy in the Y-axis direction. The frequency of this vibration Uy can be controlled by the frequency of the applied AC voltage.
The amplitude of can be controlled by the amplitude value of the applied AC voltage. After all, the upper electrodes E3, E4, the lower electrode B, the piezoelectric element 10, and a means for supplying an AC voltage (not shown) constitute the Y-axis direction excitation means 142 shown in FIG.

<Z-axis Excitation Means> Of the components shown in FIG. 6, the Z-axis excitation means 143 is the upper electrodes E1 to E.
4, a part of the lower electrode B facing this, a part of the piezoelectric element 10 sandwiched between them, and an AC supply means described later. Consider a case where a negative voltage is applied to the upper electrodes E1 and E2 and a positive voltage is applied to the upper electrodes E3 and E4 while the lower electrode B is kept at the reference potential. Then, as shown in the side sectional view of FIG.
In the piezoelectric elements under 1, E2, a stress is generated in the direction of contraction in the left-right direction of the figure (and the direction perpendicular to the paper surface), and the electrodes E3, E
A stress is generated in the piezoelectric element below 4 in a direction extending in a direction perpendicular to the plane of the drawing (and in the left-right direction in the drawing) (see polarization characteristics in FIG. 13). Here, as is apparent from the top view of FIG. 10, the upper electrodes E1 and E2 are located outside the flexible portion 12, and the upper electrodes E3 and E4 are located inside the flexible portion 12. Therefore, when the above-mentioned stresses are generated, the piezoelectric element 10 as a whole is deformed as shown in FIG. 15, and the center of gravity P of the central portion 11 is displaced by Dz in the Z-axis direction. Become. Here, when the polarities of the voltages applied to the upper electrodes E1 to E4 are reversed, a positive voltage is applied to the upper electrodes E1 and E2, and a negative voltage is applied to the upper electrodes E3 and E4, the electrodes are reversed, as opposed to FIG. A stress in the expanding direction is generated in the piezoelectric elements below E1 and E2, and a stress in the contracting direction is generated in the piezoelectric elements below the electrodes E3 and E4. As a result, the central portion 11
The center of gravity P of is displaced by -Dz in the Z-axis direction.

Therefore, the lower electrode B and the upper electrodes E1 and E2 are
And a second AC voltage having a phase opposite to that of the first AC voltage is applied between the lower electrode B and the upper electrodes E3 and E4. By doing so, the center of gravity P comes to alternately generate a displacement Dz and a displacement −Dz along the Z-axis direction, and the center portion 1
1 will oscillate along the Z axis. As described above, the central portion 11 is the vibrator 1 in the components shown in FIG.
It corresponds to 30. Therefore, it becomes possible to apply the vibration Uz in the Z-axis direction to the vibrator 130 by applying the AC voltage described above. The frequency of the vibration Uz can be controlled by the frequency of the applied AC voltage, and the amplitude of the vibration Uz can be controlled by the amplitude value of the applied AC voltage. After all, the upper electrodes E1 to E4, the lower electrode B, the piezoelectric element 10, and the means for supplying an alternating voltage (not shown) constitute the Z-axis direction excitation means 143 shown in FIG.

<X-axis direction force detecting means> Of the components shown in FIG. 6, the X-axis direction force detecting means 151 is the upper electrode A.
1, A2, a part of the lower electrode B facing the A1, A2, a part of the piezoelectric element 10 sandwiched therebetween, and a detection circuit described later. Now, with the peripheral portion 13 of this detection device fixed to the housing, the central portion 1
The phenomenon that occurs when a force fx based on the acceleration acts on the center of gravity P of 1 (vibrator 130) will be described.
First, consider a case where a force fx in the X-axis direction acts on the center of gravity P as shown in FIG. 16, as a result of the acceleration αx in the X-axis direction being applied to the center of gravity P. Due to the action of such a force fx, the flexible portion 12 is bent and deformed as shown in FIG. As a result, the upper electrodes A1 and A6 arranged along the X axis extend in the X axis direction, and the upper electrodes A5 and A2 also arranged along the X axis contract in the X axis direction. The piezoelectric element located below these upper electrodes is
Since it has the polarization characteristics as shown in FIG. 13, electric charges having the polarity as shown in FIG. 16 are generated in each upper electrode. At this time, since the lower electrode B is a single common electrode,
Even if the charges with the polarity of “+” or “−” are partially generated, they are canceled out, and the total charge is not generated.

Therefore, if the difference between the charge generated in the upper electrode A1 and the charge generated in the upper electrode A2 is obtained, the force fx acting in the X-axis direction can be obtained. Of course, the force fx acting in the X-axis direction can also be obtained by the difference between the charges generated in the upper electrode A5 and the charges generated in the upper electrode A6, but as will be described later, the upper electrodes A5, A
Since 6 is used for detecting the force fx acting in the Z-axis direction, it is not used for detecting the force fx in the X-axis direction. In addition,
In the above description, the case where the force fx acting due to the acceleration is detected is taken as an example, but the Coriolis force Fx acting due to the angular velocity can be detected in exactly the same manner. Actually, as the force acting on the center of gravity P in the X-axis direction, the force fx caused by acceleration is also the Coriolis force Fx caused by angular velocity.
Are also equivalent, and cannot be distinguished as the force detected instantaneously.

<Y-axis direction force detecting means> Of the components shown in FIG. 6, the Y-axis direction force detecting means 152 is the upper electrode A.
3, A4, a part of the lower electrode B facing the A3, A4, a part of the piezoelectric element 10 sandwiched therebetween, and a detection circuit described later. The detection principle is the same as the detection principle of the X-axis direction force detection means 151 described above. That is, what kind of phenomenon may occur when a force fy based on acceleration acts on the center of gravity P of the central portion 11 (vibrator 130) in a state where the peripheral portion 13 of this detection device is fixed to the housing. Good. As a result of the acceleration αy in the Y-axis direction being applied to the center of gravity P, when a force fy in the Y-axis direction acts, a negative charge is generated in the upper electrode A3, and the upper electrode A4.
Will generate a positive charge. Therefore, the upper electrode A
If the difference between the charge generated in 3 and the charge generated in the upper electrode A4 is obtained, the force fy acting in the Y-axis direction can be obtained. The detection of the Coriolis force Fy acting due to the angular velocity is exactly the same.

<Z-axis direction force detecting means> Of the components shown in FIG. 6, the Z-axis direction force detecting means 153 is the upper electrode A5.
.About.A8, a part of the lower electrode B facing the same, a part of the piezoelectric element 10 sandwiched between them, and a detection circuit described later. Now, with the peripheral portion 13 of this detection device fixed to the housing, the central portion 11
The phenomenon that occurs when the force fz based on the acceleration acts on the center of gravity P of the (vibrator 130) will be described. First, as a result of applying the acceleration αz in the Z-axis direction to the center of gravity P,
As shown in FIG. 17, the force fz in the Z-axis direction with respect to the center of gravity P
Consider the case when Due to the action of such a force fz, the flexible portion 12 is bent and deformed as shown in FIG. As a result, the upper electrodes A1, A8, A2, A7 arranged in the outer ring-shaped region contract, so that "-" charges are generated on the upper electrode side, and the upper electrodes A5, A4, A6 arranged in the inner ring-shaped region. , A3 is elongated, so that "+" charges are generated on the upper electrode side. At this time, since the lower electrode B serves as a single common electrode, even if charges of "+" or "-" are partially generated, they are canceled out, and no total charge is generated.

Therefore, the sum of the charges generated on the upper electrodes A5 and A6 and the sum of the charges generated on the upper electrodes A7 and A8,
The force fz acting in the Z-axis direction can be obtained by obtaining the difference between Of course, the Coriolis force Fz acting due to the angular velocity can be detected in exactly the same manner.

Here, when the forces fx, fy, and fz act, respectively, the polarities of the charges generated in the respective upper electrodes are summarized, and the table shown in FIG. 18 is obtained. In the table, "0" indicates that the piezoelectric element partially expands but partially contracts, so that positive and negative are canceled out and no electric charge is generated as a whole. As described above, since each upper electrode has a line-symmetrical shape with respect to the X axis or the Y axis, the upper electrode that generates charges by the action of the force fx is
Even if the force fy acts, no charge is generated, and conversely, no charge is generated even when the force fx acts on the upper electrode that generates a charge by the action of the force fy. Thus, in order to avoid the interference with the other axis, it is important to make the electrode shape line-symmetric. The table in FIG. 18 shows the polarities when the positive force + fx, + fy, + fz of each axis acts, but the negative force −fx, −fy, − of each axis is shown.
When fz acts, electric charges of opposite polarities to those in this table appear. The fact that such a table is obtained can be easily understood by referring to the deformed state shown in FIGS. 16 and 17 and the arrangement of the upper electrodes shown in FIG. Further, the magnitude of the applied force can be detected as the generated charge amount.

Based on this principle, the forces fx, fy,
In order to detect fz (or Coriolis force Fx, Fy, Fz), for example, a detection circuit as shown in FIG. 19 may be prepared. In this detection circuit, the Q / V conversion circuits 31 to 38 are circuits that convert the amount of charge generated in each of the upper electrodes A1 to A8 into a voltage value when the potential of the lower electrode B is used as a reference potential. From this circuit, for example, when "+" charges are generated on the upper electrode, a positive voltage (with respect to the reference potential) according to the amount of generated charges is output, and conversely, "+" charges are generated on the upper electrode. When a "-" charge is generated, a negative voltage (relative to the reference potential) corresponding to the generated charge amount is output. The voltages V1 to V8 thus output
Are given to the arithmetic units 41 to 43, and these arithmetic units 41 to 43 are
The output of 43 is obtained at terminals Tx, Ty, Tz. Here, the voltage value of the terminal Tx with respect to the reference potential becomes the detected value of the force fx (or Coriolis force Fx), and the voltage value of the terminal Ty with respect to the reference potential becomes the detected value of the force fy (or Coriolis force Fy). The voltage value with respect to the reference potential becomes the detection value of the force fz (or Coriolis force Fz).

It will be understood from the table of FIG. 18 that the voltage values obtained at the output terminals Tx, Ty, Tz become the detection values of the forces fx, fy, fz. For example, when the force fx acts, "+" charges are generated on the upper electrode A1 and "-" charges are generated on the upper electrode A2. Therefore,
V1 is a positive voltage and V2 is a negative voltage. Therefore, the arithmetic unit 41
Then, the sum of absolute values of the voltages V1 and V2 is obtained by performing the calculation of V1-V2, and this is output to the terminal Tx as the detected value of the force fx. Similarly, when the force fy acts, "-" charges are generated on the upper electrode A3, and "+" charges are generated on the upper electrode A4.
Therefore, V3 is a negative voltage and V4 is a positive voltage. Therefore, the arithmetic unit 42 calculates V4−V3 to obtain the sum of the absolute values of the voltages V3 and V4, which is output to the terminal Ty as the detected value of the force fy. When the force fz acts, the upper electrodes A5, A
A charge of "+" is generated at 6, and a charge of "-" is generated at the upper electrodes A7 and A8. Therefore, V5 and V6 are positive, and V7 and V8 are negative. Therefore, the calculator 43
By performing the calculation of V5 + V6-V7-V8, the sum of the absolute values of the voltages V5 to V8 is obtained, and this is output to the terminal Tz as the detected value of the force fz.

The point to be noted here is that each output terminal Tx,
This means that the detection values obtained for Ty and Tz do not include the other axis component. For example, as shown in the table of FIG. 18, when only the force fx acts, no charge is generated in the upper electrodes A3 and A4 for detecting the force fy, and no detection voltage is obtained at the terminal Ty. . At this time, electric charges (opposite polarities) are generated in the upper electrodes A5 and A6 for detecting the force fz, but the voltages V5 and V6 are added to each other in the calculator 43 and thus cancel each other out.
No detection voltage can be obtained at. Similarly, when only the force fy acts, no detection voltage can be obtained except at the terminal Ty. Similarly, when only the force fz acts, no detection voltage can be obtained except at the terminal Tz. In this way, the XYZ three-axis direction components can be detected independently.

Although a specific configuration example of the detection apparatus shown in FIG. 6 has been described above, various other configuration examples are possible. In short, what kind of structure is required if the excitation means that mechanically vibrates the vibrator 130 in the predetermined axis direction and the detection means that can detect the force acting on the vibrator 130 in each axial direction are realized. You can take it.

§3. Conventionally Proposed Detection Operation With a detection device as shown in FIG. 6, the acceleration α in each axial direction is
x, αy, αz and angular velocities ωx, ωy, ω around the angular axis
A conventional detection operation for detecting z and z is shown in the flowchart of FIG. 20 as a "basic detection operation". This detecting operation is performed by the international application PCT / J based on the above-mentioned Patent Cooperation Treaty.
The method disclosed in P93 / 00390.

First, in step S11, the vibrator 1
A state in which 30 is not vibrated (that is, each excitation means 14
1, 142, 143 are not driven), the detection values of the force detection means 151, 152, 153 are obtained. This is one in which the detection device shown in FIG. 6 is operated as the acceleration detection device shown in FIG. 7, and each force detection means 151, 152,
The detected value of 153 is the forces fx, fy, f due to acceleration.
z. Since the oscillator 130 is not vibrating, the Coriolis forces Fx, Fy, Fz due to the angular velocity are not detected. Since the force f due to acceleration and the acceleration α have a relationship of f = m · α based on the mass m of the vibrator 130, based on the obtained forces fx, fy, and fz,
It is possible to detect the accelerations αx, αy, αz in each axial direction.

Then, in step S12, the detection value Fy of the Y-axis direction force detecting means 152 is obtained with the vibration Uz applied to the vibrator 130 (that is, the state in which the Z-axis direction exciting means 143 is driven). And Fy = 2m · vz
The angular velocity ωx around the X axis is detected based on the formula ωx. Here, m is the mass of the oscillator 130, and vz
Is the instantaneous velocity of the vibrator 130 in the Z-axis direction. This detection method is based on the principle shown in FIG. In addition,
The instantaneous velocity vz can be estimated from the operating state of the Z-axis direction excitation means 143. For example, in the specific configuration example shown in §2 described above, the Z-axis direction excitation means 143 is driven by supplying a predetermined AC voltage to the upper electrodes E1 to E4. , Frequency, and phase at the moment, the instantaneous velocity vz
It is possible to estimate

In the next step S13, the vibrator 130
In the state where the vibration Ux is applied to the shaft (that is, the state where the X-axis direction excitation means 141 is driven), the Z-axis direction force detection means 153.
The detection value Fz of is obtained. And Fz = 2m · vx · ωy
The angular velocity ωy about the Y axis is detected based on the following equation. Here, vx is the instantaneous velocity of the vibrator 130 in the X-axis direction, and can be estimated from the operating state of the X-axis direction excitation means 141. This detection method is based on the principle shown in FIG.

In the next step S14, the vibrator 130
In a state where the vibration Uy is applied to the (i.e., the state where the Y-axis direction excitation means 142 is driven), the X-axis direction force detection means 151.
The detection value Fx of is obtained. And Fx = 2m · vy · ωz
The angular velocity ωz about the Z axis is detected based on the following equation. Here, vy is the instantaneous velocity of the vibrator 130 in the Y-axis direction, and can be estimated from the operating state of the Y-axis direction excitation means 142. This detection method is based on the principle shown in FIG.

Finally, as long as the detection operation is continued through step S15, the processing from step S11 is repeatedly executed. In this way, the step of detecting the accelerations αx, αy, αz in each axial direction without vibrating the vibrator 130 (step S11), and the speed around each axis with the vibrator 130 vibrating in the predetermined direction. By separately performing the steps of detecting ωx, ωy, and ωz (steps S12 to S14), both acceleration and angular velocity can be obtained. In an environment in which the acceleration and the angular velocity are constantly acting, in the angular velocity detection process of steps S12 to S14, the forces fx, fy, and fz caused by the acceleration are detected by being mixed with the Coriolis forces Fx, Fy, and Fz. Fx, f detected in step S11
Subtract using the values of y and fz to obtain Coriolis force Fx and Fx
It is necessary to extract only the y and Fz components.

The problem with this "basic detection operation" is that the responsiveness deteriorates when it is used in an application in which the values of acceleration and angular velocity are continuously measured. In automobiles, industrial machines, etc., it is often required to continuously obtain the values of acceleration and angular velocity that change from moment to moment in a constant time period. However, when performing the detection operation based on the flowchart shown in FIG. 20, the vibrator that has been stationary in step S11 is vibrated in the Z-axis direction in step S12, in the X-axis direction in step S13, and in step S14 Y Vibrate axially and repeat step S
Need to be stationary at 11. It is very difficult to change such mechanical vibration conditions for the oscillator at high speed, and in reality, in order to proceed to the next step in the detection operation of FIG. It takes some time to get Therefore, the responsiveness is inevitably deteriorated.

§4. Caused by force and angular velocity due to acceleration
Separation from Force Caused The feature of the detection operation according to the present invention is that acceleration detection and angular velocity detection are performed simultaneously. For that purpose, it is necessary to separate the force detected by each force detecting means 151, 152, 153 into a force caused by acceleration and a Coriolis force caused by angular velocity. Here, this separation method will be described with reference to a specific example.

Here, a specific example will be described taking the model shown in FIG. 3 as an example. FIG. 3 is a diagram for explaining the detection principle of the angular velocity ωx around the X axis. That is, when the Coriolis force Fy generated in the Y-axis direction is detected in the state where the vibration Uz in the Z-axis direction is applied to the vibrator 130, the angular velocity around the X-axis is calculated from the relational expression Fy = 2m · vz · ωx. ωx will be obtained. Therefore, the vibration U in the Z-axis direction as shown in FIG.
Consider a case where an angular velocity ωx around the X-axis as shown in FIG. 7B acts under the condition that z is given. In each case, the horizontal axis represents time t. The vibration Uz indicates a change in the physical position of the vibrator 130, and in this example, it means that a sine motion is performed in the vertical direction. Further, the angular velocity ωx that acts in this case is an angular velocity around the positive direction of the X axis (for example, clockwise), and gradually increases and gradually decreases with time. At this time, the Coriolis force Fy generated in the Y-axis direction is obtained by the relational expression Fy = 2m · vz · ωx. Here, the instantaneous velocity vz of the vibrator 130 in the Z-axis direction is the phase of the vibration Uz (π It will be shifted by / 2). This is because the instantaneous velocity of an object that is moving up and down in a sine becomes maximum at the moment of passing through the center position and becomes 0 at the highest point and the lowest point (here, FIG. 21 (a)). In the vibration shown in, the velocity in the downward direction is positive, and the velocity in the upward direction is negative). Since the mass m of the oscillator 130 is constant, the Coriolis force Fy
Is determined by the product of the instantaneous velocity vz and the angular velocity ωx,
It becomes something like FIG.21 (c). After all, in the model of FIG. 3, the angular velocity ω as shown in FIG. 21 (b) is obtained in the state where the vibration Uz as shown in FIG.
When x acts, Coriolis force Fy as shown in FIG. 21 (c) is generated.

On the other hand, what kind of force is generated in the Y-axis direction when the acceleration in the Y-axis direction acts on the vibrator 130? Since the force fy in the Y-axis direction generated by the acceleration αy in the Y-axis direction is given by the relational expression fy = m · αy, a force fy proportional to the given acceleration αy is generated. Therefore, if the linearly increasing acceleration αy is applied to the vibrator 130, a force fy in the Y-axis direction as shown in FIG. 21D is generated.

Then, in the model of FIG. 3, the vibrator Uz in the Z-axis direction as shown in FIG.
When the angular velocity ωx around the X-axis as shown in FIG. 21 (b) acts and the linearly increasing acceleration αy in the Y-axis direction acts in the state where Will such a force be observed? In this case, as a matter of course, the Coriolis force Fy as shown in FIG.
A synthetic force corresponding to the sum of acceleration-based forces fy as shown in (d) is observed. FIG. 22 shows such a combined force fy + Fy.

If the resultant force fy + Fy can be separated into the force fy and the Coriolis force Fy, the acceleration αy in the Y-axis direction can be obtained from the former and the angular velocity around the X-axis can be obtained from the latter. ωx can be obtained. That is, the acceleration and the angular velocity can be detected simultaneously. The inventors of the present application have found that this separation can be performed by paying attention to the following points. That is, if only the bias component of the combined force fy + Fy shown in FIG. 22 is extracted, only the force fy shown in FIG. 21 (d) can be taken out, and if only the amplitude component is extracted, it is shown in FIG. 21 (c). Only the Coriolis force Fy shown can be taken out. In the first place, Coriolis force F shown in Fig. 21 (c)
y is the vibration Uz shown in FIG.
The angular velocity ωx shown in 1 (b) is amplitude-modulated. Therefore, the information of the angular velocity ωx is included only as the amplitude component in the synthetic force. On the other hand, the force fy shown in FIG. 21 (d) does not include the frequency component of the vibration Uz.
It is included only as a bias component. From this point of view, it can be understood that the force fy can be extracted by extracting only the bias component of the combined force fy + Fy, and the Coriolis force Fy can be extracted by extracting only the amplitude component.

In order to separate the acceleration-based force f and the angular velocity-based Coriolis force F based on such a principle, the frequency of the vibration U is set to the frequency of the acceleration or angular velocity to be detected. The frequency must be sufficiently high to be discriminable. In other words, the detection device according to the present invention can detect only a frequency component that is sufficiently lower than the frequency of the vibration U in the acceleration and the angular velocity to be detected. However, such a restriction poses no problem in practical use as a detection device mounted on an automobile or an industrial machine. Specifically, when vibrating a vibrator using a piezoelectric element as described in §2, 20 kHz
It is most efficient to vibrate at a resonance frequency of the order of magnitude.
In this case, it is sufficiently possible to detect acceleration or angular velocity having a frequency component of several hundreds Hz or less, and such performance is required for a detection device mounted on a general automobile or industrial machine. Is fully satisfied.

Now, based on the above-mentioned principle, as a method of separating the combined force into a bias component and an amplitude component,
For example, a method using a frequency filter can be used. However, in recent years, with the spread of computers, it has become common to perform A / D conversion of the obtained electric signal and perform digital processing. The inventor of the present application has found out the following separation method utilizing such digital processing.

First, regarding the detection signal of the combined force fy + Fy as shown in FIG. 22, as shown in FIG.
Extract P9. Then, as shown in FIG. 24, the demarcation lines Q1 to Q indicating the positions of the respective inflection points P1 to P9 on the time axis t.
9 is defined, and reference lines Q12 to Q89 (shown by broken lines in FIG. 24) that pass through the intermediate positions of the adjacent partition lines are defined.
Then, on each reference line, the reference point m having the average value of the signal values of the inflection points on both sides thereof is plotted. FIG. 25 shows the reference points m1 to m8 thus plotted. For example, the reference point m1 is a reference line Q1 having an average value of the signal values of the inflection point P1 and the inflection point P2.
This is the point above 2. Thus, the reference points m1 to
When m8 is obtained, as shown in FIG. 26, a signal waveform obtained by sequentially connecting these is obtained. The signal waveform thus obtained corresponds to the bias component of the original combined force fy + Fy, and eventually corresponds to the force fy based on the acceleration αy. Once the bias component is obtained, the signal waveform corresponding to the amplitude component can be obtained by subtracting this from the original combined force, and as a result, the Coriolis force Fy is obtained.
It is possible to obtain a signal waveform corresponding to. The magnitude of the angular velocity ωx depends on the Coriolis force Fy, as shown in FIG.
It is obtained by extracting the envelope E of the signal waveform corresponding to. The direction of the angular velocity ωx can be obtained from the phase difference between the obtained Coriolis force Fy and the vibration Uz shown in FIG. 21 (a). For example, when a positive angular velocity ωx as shown in FIG. 21 (b) is applied, the obtained Coriolis force Fy is obtained for the waveform of the vibration Uz shown in FIG. 21 (a).
As shown in FIG. 21 (c), the waveform in FIG. 21 is obtained by shifting the phase to the right by (π / 2). However, when the negative angular velocity −ωx is added, the same waveform in FIG. The waveform of the vibration Uz shown in (a) is obtained by reversing the positive / negative of Fig. 21 (c), and the Coriolis force waveform is obtained. The phase of the waveform of the vibration Uz is (π / 2) It will be shifted to the left.

§5. First embodiment of the detection device according to the present invention
Example A detection device according to the present invention is based on the basic principle described in §4 above, and a force f (bias component) based on acceleration of a synthetic force is obtained.
The acceleration and the angular velocity can be detected at the same time by using a signal separating means for separating into a Coriolis force F (amplitude component) based on the angular velocity. FIG. 28 is a block diagram showing the basic configuration of the detection device according to the first embodiment of the present invention. This detecting device has an X-axis direction signal separating means 161, a Y-axis direction signal separating means 162, and a Z-axis direction signal separating means 163 added to each component of the detecting device shown in FIG. 171-173 and the angular velocity calculation means 181-183 are added.

Each of the signal separating means 161 to 163 is based on the basic principle described in §4, and each force detecting means 151.
˜153 resulting synthetic forces fx + Fx, fy + Fy,
fz + Fz are respectively fx and Fx, fy and Fy, fz
And Fz. Further, each of the acceleration calculation means 171 to 173 uses the mass m of the vibrator 130 to calculate f
= M · α, the acceleration αx in each axis direction,
This is a device for calculating and outputting αy and αz. Oscillator 13
Since the acceleration acting on 0 is detected as the force f irrespective of the vibration of the vibrator 130, each acceleration calculation means 171.
.About.173 output accelerations .alpha.x, .alpha.y, .alpha.z in the respective axial directions irrespective of the operations of the respective excitation means 141-143.

On the other hand, each angular velocity calculating means 181 to 183
Is an apparatus for calculating and outputting angular velocities ωx, ωy, ωz around each axis based on the principle shown in FIGS. 3 to 5. However, the detection of the angular velocities ωx, ωy, ωz is closely related to the vibration of the vibrator 130, as shown in the principle diagrams of FIGS. In other words, each angular velocity calculation means 181
183 to 183 cannot calculate the angular velocity unless the operating states of the respective excitation means 141 to 143 are taken into consideration. This will be explained for each individual case.

First, based on the principle shown in FIG. 3, in order to detect the angular velocity ωx about the X axis, the Z-axis direction excitation means 14 is used.
In a state in which the vibration Uz in the Z-axis direction is applied to the vibrator 130 by driving 3, the Y-axis direction Coriolis force Fy separated by the Y-axis direction signal separating means 162 is applied to the angular velocity calculating means 182. The angular velocity calculation means 182 is Fy = 2 m
The angular velocity ωx around the X axis is calculated based on the calculation formula vz · ωx, and this is output. At this time, the vibrator 13
The instantaneous velocity vz of 0 in the Z-axis direction is estimated based on the operation mode of the Z-axis direction excitation means 143. For example, §
In the detection device having the specific structure described in 2, a predetermined AC voltage is supplied to the upper electrodes E1 to E4 to give the vibration Uz, but the instantaneous speed of the vibrator 130 is supplied at that time. Can be determined based on the amplitude, frequency, and phase of the AC voltage to be generated (the theoretical calculation formula can be used to determine the relationship between the AC voltage to be supplied and the instantaneous speed of the vibrator, and It is also possible to prepare a table that measures the instantaneous speed of the oscillator for one cycle). Note that, in the output of the angular velocity calculation means 182 of FIG. 28, “FIG. 3: ωx (Uz)” is described as “under the condition that the vibration Uz is applied to the vibrator 130 based on the principle shown in FIG. The angular velocity ωx is output ”.

Next, based on the principle shown in FIG. 4, in order to detect the angular velocity ωy about the Y axis, the X-axis direction excitation means 14 is used.
In the state in which the oscillator 1 is driven to give the vibration Ux in the X-axis direction, the Coriolis force Fz in the Z-axis direction separated by the Z-axis direction signal separating means 163 is applied to the angular velocity calculating means 183. The angular velocity calculation means 183 has Fz = 2 m
The angular velocity ωy about the Y axis is calculated based on the calculation formula vx · ωy, and this is output. At this time, the vibrator 13
The instantaneous velocity vx of 0 in the X-axis direction is estimated based on the operation mode of the X-axis direction excitation means 141. Note that FIG.
The output of the angular velocity calculation means 183 of FIG.
“X)” indicates that “the angular velocity ωy is output under the condition that the vibration Ux is applied to the vibrator 130 based on the principle shown in FIG. 4”.

Further, in order to detect the angular velocity ωz about the Z axis based on the principle shown in FIG. 5, the Y axis direction excitation means 14 is used.
In a state in which the vibration Uy is applied to the vibrator 130 by driving 2 in the Y axis direction, the Coriolis force Fx in the X axis direction separated by the X axis direction signal separating means 161 is applied to the angular velocity calculating means 181. The angular velocity calculation means 181 has Fx = 2 m
The angular velocity ωz around the Z axis is calculated based on the calculation formula vy · ωz, and this is output. At this time, the vibrator 13
The instantaneous velocity vy of 0 in the Y-axis direction is estimated based on the operation mode of the Y-axis direction excitation means 142. Note that FIG.
The output of the angular velocity calculation means 181 of FIG.
"y)" indicates that "the angular velocity ωz is output under the condition that the vibration Uy is applied to the vibrator 130 based on the principle shown in FIG. 5".

Thus, according to the detecting device shown in FIG. 28, finally, the acceleration calculating means 171 outputs the acceleration αx in the X-axis direction, the acceleration calculating means 172 outputs the acceleration αy in the Y-axis direction, and the acceleration calculating means 173 outputs the acceleration αx. The acceleration αz in the Z-axis direction is output, and the angular velocity calculating means 182 outputs the angular velocity ωx about the X axis, the angular velocity calculating means 183 outputs the angular velocity ωy about the Y axis, and the angular velocity calculating means 181 to Z. The angular velocities ωz about the axes are output respectively. In addition, from each of the angular velocity calculating means 181 to 183 shown in FIG. 28, “FIG. 31: ωy (U
z) ”,“ FIG. 32: ωz (Ux) ”, and“ FIG. 30: ωx ”.
Although it is shown that the output "(Uy)" is also obtained, this will be described in §6.

With the detection device shown in FIG. 28, accelerations αx, αy, αz in the respective axis directions and angular velocities ω around the respective axes are obtained.
The detection operation for detecting x, ωy, ωz is shown in the flow chart of FIG. 29 as "detection operation according to the first embodiment".

First, in step S21, the vibrator 1
In a state where the vibration Uz is applied to 30 (that is, the Z-axis direction excitation means 143 is driven), the Y-axis direction force detection means 1
The combined force fy + Fy is taken out from 52 and separated into the force fy and the Coriolis force Fy by the Y-axis direction signal separating means 162. Then, in the acceleration calculation means 172, the force fy
The acceleration αy is calculated based on the above, and is output, and the angular velocity calculating means 182 calculates the angular velocity ωx based on the Coriolis force Fy and outputs it. Thus, in step S21, the acceleration αy and the angular velocity ωx can be detected.

Next, in step S22, the vibrator 1
When the vibration Ux is applied to 30 (that is, the X-axis direction excitation means 141 is driven), the Z-axis direction force detection means 1
The combined force fz + Fz is taken out from 53, and is separated into the force fz and the Coriolis force Fz by the Z-axis direction signal separating means 163. Then, in the acceleration calculation means 173, the force fz
The acceleration αz is calculated based on the above, and is output, and the angular velocity calculating means 183 calculates the angular velocity ωy based on the Coriolis force Fz and outputs it. Thus, in step S21, the acceleration αz and the angular velocity ωy can be detected.

Then, in step S23, the vibrator 1
When the vibration Uy is applied to 30 (that is, the Y-axis direction excitation means 142 is driven), the X-axis direction force detection means 1
The combined force fx + Fx is extracted from 51, and is separated into the force fx and the Coriolis force Fx by the X-axis direction signal separating means 161. Then, in the acceleration calculation means 171, the force fx
The acceleration αx is calculated based on the above, and is output, and the angular velocity calculating means 181 calculates the angular velocity ωz based on the Coriolis force Fx and outputs it. Thus, in step S21, the acceleration αx and the angular velocity ωz can be detected.

Finally, as long as the detection operation is continued through step S24, the processing from step S21 is repeatedly executed. In the "detection operation according to the first embodiment" shown in FIG. 29, one step is omitted as compared with the "basic detection operation" shown in FIG. That is, in the "basic detection operation", in order to detect the acceleration, in step S11, the detection is performed while keeping the vibrator in a stationary state. In the "detection operation", acceleration can be detected even when the vibrator is vibrated, so that the vibrator does not need to be stationary. Therefore, in the detection device shown in FIG. 28, the responsiveness is improved as compared with the conventionally proposed detection device.

§6. Second embodiment of the detection device according to the present invention
EXAMPLE Now, in §5, the detection device having the basic configuration shown in FIG. 28 and its operation have been described. According to the operation, regarding the angular velocity, the angular velocity ωx around the X axis is output from the angular velocity calculating means 182 based on the principle of FIG. 3, and the angular velocity ωy around the Y axis is based on the principle of FIG. The angular velocity ωz about the Z axis is output from the angular velocity calculation means 181 based on the principle of FIG.
However, in FIG. 28, “FIG. 30: ωy (Uz)” and “FIG. 31:
There is a description that other outputs such as “ωz (Ux)” and “FIG. 29: ωx (Uy)” can be obtained. This is based on the principle of detecting each angular velocity in addition to the combinations of FIGS.
This indicates that the combination of FIG. 32 also exists.
That is, the detection of the angular velocity using the Coriolis force is as follows: “When the Coriolis force generated in the second coordinate axis direction is detected when the vibration is applied in the first coordinate axis direction, the angular velocity around the third coordinate axis is obtained. It is based on the basic principle of "is possible". How are the first, second, and third coordinate axes in this basic principle to the X-axis, Y-axis, and Z-axis coordinate axes in the XYZ three-dimensional coordinate system? It does not matter if they correspond.

Even in the method of detecting the angular velocity ωx about the same X axis, in FIG. 3, the Coriolis force Fy generated in the Y axis direction when the vibration Uz in the Z axis direction is applied is detected. On the other hand, in FIG. 30, the Coriolis force Fz generated in the Z-axis direction when the vibration Uy in the Y-axis direction is applied is detected. Further, even in the method of detecting the same angular velocity ωy about the Y axis, in FIG. 4, the Coriolis force Fz generated in the Z axis direction when the vibration Ux in the X axis direction is applied is detected. In FIG. 31, the Coriolis force Fx generated in the X-axis direction when the vibration Uz in the Z-axis direction is applied is detected. Similarly, the angular velocity ω around the same Z axis
Even with the method of detecting z, in FIG. 5, the Coriolis force F generated in the X-axis direction when the vibration Uy in the Y-axis direction is applied.
While x is detected, in FIG. 32, the Coriolis force F generated in the Y-axis direction when the vibration Ux in the X-axis direction is applied.
It is detecting y.

Therefore, it is possible to operate the detection device shown in FIG. 28 based on the principle shown in FIGS. 30 to 32. This will be explained for each individual case.

First, in order to detect the angular velocity ωx about the X axis based on the principle shown in FIG. 30, the Y-axis direction excitation means 1 is used.
In a state where the vibrator 130 is driven by the vibration Uy in the Y-axis direction, the Coriolis force Fz in the Z-axis direction separated by the Z-axis direction signal separating means 163 is applied to the angular velocity calculating means 183. The angular velocity calculation means 183 uses Fz = 2
The angular velocity ωx around the X axis is calculated based on the arithmetic expression m · vy · ωx, and this is output. At this time, the oscillator 1
The instantaneous velocity vy of 30 in the Y-axis direction is estimated based on the operation mode of the Y-axis direction excitation means 142. The output of the angular velocity calculation means 183 is described as "FIG. 30: ωx (Uy)" because "the angular velocity ωx is output under the condition that the vibration Uy is applied to the vibrator 130 based on the principle shown in FIG. "."

Next, based on the principle shown in FIG. 31, in order to detect the angular velocity ωy about the Y-axis, the Z-axis direction excitation means 1 is used.
In a state where the vibration Uz is applied to the vibrator 130 by driving 43, the Coriolis force Fx in the X-axis direction separated by the X-axis direction signal separating means 161 is applied to the angular velocity calculating means 181. The angular velocity calculation means 181 uses Fx = 2
The angular velocity ωy around the Y axis is calculated based on the calculation formula m · vz · ωy, and this is output. At this time, the oscillator 1
The instantaneous velocity vz of 30 in the Z-axis direction is estimated based on the operation mode of the Z-axis direction excitation means 143. In the output of the angular velocity calculation means 181, the description "FIG. 31: ωy (Uz)" means that the angular velocity ωy is output under the condition that the vibration Uz is applied to the vibrator 130 based on the principle shown in FIG. "."

Further, in order to detect the angular velocity ωz around the Z axis based on the principle shown in FIG. 32, the X axis direction excitation means 1 is used.
In the state where 41 is driven to apply the vibration Ux in the X-axis direction to the vibrator 130, the Coriolis force Fy in the Y-axis direction separated by the Y-axis direction signal separating means 162 is applied to the angular velocity calculating means 182. The angular velocity calculation means 182 uses Fy = 2
The angular velocity ωz around the Z axis is calculated based on the arithmetic expression m · vx · ωz, and this is output. At this time, the oscillator 1
The instantaneous velocity vx of 30 in the X-axis direction is estimated based on the operation mode of the X-axis direction excitation means 141. In the output of the angular velocity calculation means 182, “FIG. 32: ωz (Ux)” means that the angular velocity ωz is output under the condition that the vibration 130 is applied to the vibrator 130 based on the principle shown in FIG. "."

As described above, the detection device shown in FIG.
A detection method based on the three principles of FIGS. 3 to 5, and FIG.
~ Any of the three detection methods based on the principle of Fig. 32 can be applied, but the inventor of the present application succeeds in selecting three principles out of the six principles in total. , And found that the detection operation and the device configuration can be simplified. The second embodiment described here is a further simplification of the first embodiment described in §5 based on such a basic idea.

Now, in the device according to the first embodiment shown in FIG. 28, as a principle of angular velocity detection, ωx according to FIG.
It is assumed that three principles, namely, detection of ω, detection of ωy according to FIG. 31, and detection of ωz according to FIG. 32 are selected. Then, the detection device according to the first embodiment shown in FIG. 28 is simplified to the detection device according to the second embodiment as shown in FIG.
The detection device of FIG. 33 is obtained by removing the Y-axis direction excitation means 142 and the angular velocity calculation means 183 from the detection device of FIG. As long as the selected three detection principles of FIG. 3, FIG. 31, and FIG. 32 are adopted, it is not necessary to give the vibration Uy in the Y-axis direction, and the angular velocity calculation using the Coriolis force Fz in the Z-axis direction is not necessary. is there.

With the detection device shown in FIG. 33, the accelerations αx, αy, αz in the respective axis directions and the angular velocities ω around the respective axes are obtained.
The detection operation for detecting x, ωy, and ωz is shown in the flowchart of FIG. 34 as "detection operation according to the second embodiment".

First, in step S31, the oscillator 1
In the state where the vibration Uz is applied to 30 (that is, the state in which the Z-axis direction excitation means 143 is driven), the following two types of detection are performed. As the first detection, the Y-axis direction force detecting means 152
The combined force fy + Fy is taken out from and is separated into the force fy and the Coriolis force Fy by the Y-axis direction signal separating means 162. Then, the acceleration calculation means 172 calculates the acceleration αy based on the force fy and outputs it, and the angular velocity calculation means 182 calculates the angular velocity ω based on the Coriolis force Fy.
It calculates x and outputs it. This is a detection based on the principle of FIG. At the same time, the following second detection is performed. That is, the combined force fx + Fx is taken out from the X-axis direction force detecting means 151, and is separated into the force fx and the Coriolis force Fx by the X-axis direction signal separating means 161. And
The acceleration calculating means 171 calculates the acceleration αx based on the force fx and outputs it, and the angular velocity calculating means 181 calculates the angular velocity ωy based on the Coriolis force Fx and outputs it. This is detection based on the principle of FIG. Thus, in step S31, the acceleration α
y, αy and angular velocities ωx, ωy can be detected.

Next, in step S32, the vibrator 1
In the state where the vibration Ux is applied to 30 (that is, the state where the X-axis direction excitation means 141 is driven), the following two types of detection are performed. The first detection is the Z-axis direction force detection means 153.
The combined force fz + Fz is taken out from and the force fz and the Coriolis force Fz are separated by the Z-axis direction signal separating means 163. Then, the acceleration calculating means 173 calculates the acceleration αz based on the force fz and outputs it. This first
In the detection of, only the acceleration needs to be detected. (If the principle of FIG. 4 is used, the angular velocity ωy is calculated based on the Coriolis force Fz.
However, the angular velocity ωy has already been obtained in step S31). At the same time, the second
Is detected. That is, the combined force fy + Fy is taken out from the Y-axis direction force detecting means 152, and separated by the Y-axis direction signal separating means 162 into the force fy and the Coriolis force Fy.
Then, in the angular velocity calculation means 182, the Coriolis force F
The angular velocity ωz is calculated based on y and is output. This is detection based on the principle of FIG. Thus
In step S32, the acceleration αz and the angular velocity ωz can be detected.

Finally, after step S33, the process from step S31 is repeatedly executed as long as the detection operation is continued. In the "detection operation according to the second embodiment" shown in FIG. 34, one step is omitted as compared with the "detection operation according to the first embodiment" shown in FIG.
That is, in the "detection operation according to the first embodiment", the detection is performed in the state where the vibrator is vibrated in the three axis directions of the X axis, the Y axis, and the Z axis. In the "detection operation according to the second embodiment", all the detection can be performed only in a state where the X-axis and the Z-axis are vibrated.
Therefore, in the detection device shown in FIG. 33, the responsiveness is further improved.

§7. Third embodiment of the detection device according to the present invention
Example Up to now, the acceleration αx in each of the X-axis, Y-axis, and Z-axis directions,
αy, αz and angular velocities ωx, ωy, ωz around each axis
The example of the three-dimensional acceleration / angular velocity detection device that detects the six components of However, depending on the application, X
There is a sufficient demand for a two-dimensional acceleration / angular velocity detection device that needs to obtain only the accelerations αx and αy in the biaxial directions of the Y-axis and the Y-axis and the angular velocities ωx and ωy around the two axes. The configuration of the third embodiment in which the present invention is applied to such a two-dimensional detection device is further simplified.

FIG. 35 is a block diagram showing the basic structure of the third embodiment. Compared to the second embodiment shown in FIG. 33, the X-axis direction excitation means 141, the Z-axis direction force detection means 153, and the acceleration calculation means 173 are further deleted. Even with such a configuration, the required acceleration and angular velocity can be detected without any trouble. That is, the acceleration αx is obtained by the acceleration calculation means 171, and the acceleration αy
Is obtained by the acceleration calculation means 172. Further, the angular velocity ωx is obtained by the angular velocity calculation means 182 (principle of FIG. 3) in the state where the vibration Uz is given by the Z-axis direction excitation means 143, and the angular velocity ωy is the Z-axis direction excitation means 14.
It is obtained by the angular velocity calculation means 181 in the state where the vibration Uz is given by 3 (the principle of FIG. 31).

With the detection apparatus shown in FIG. 35, biaxial accelerations αx and αy and biaxial angular velocities ωx and ω are obtained.
The detection operation for detecting y and y is step S31 in the "detection operation according to the second embodiment" shown in FIG.
Just enough. In other words, the “detection operation according to the third embodiment” is an operation that includes only step S31 in FIG. This means that if the vibrator 130 is always vibrated only in the Z-axis direction, all detected values can be obtained. As described above, since it is not necessary to change the vibration mode of the vibrator, a very efficient detection operation is possible, and the response becomes extremely good.

§8. Specific detection suitable for two-dimensional detection
Structure of output device As described in §7 above, the accelerations αx and αy in the biaxial directions of the X and Y axes and the angular velocities ωx and ωy about the biaxials.
In the two-dimensional detection device aiming to obtain only, as shown in the block diagram of FIG. 35, as the excitation means, only the Z-axis direction excitation means 143 may be provided.
As the force detecting means, only the X-axis direction force detecting means 151 and the Y-axis direction force detecting means 152 may be provided. Therefore, in such a two-dimensional detection device, the number of upper electrodes provided on the piezoelectric element can be reduced as compared with the three-dimensional detection device. For example, in the three-dimensional detection device shown in FIG. 10, on the piezoelectric element 10, four upper electrodes E1 to E4 functioning as excitation means, and eight upper electrodes A1 to A8 functioning as force detection means, Is provided to realize excitation and force detection in all three axes. However, a two-dimensional detection device can be realized with a structure having fewer upper electrodes.

FIG. 36 is a top view showing a structural example of a specific detection device suitable for two-dimensional detection, and FIG. 37 is a side sectional view taken along the XZ plane of this detection device. The correspondence between each upper electrode in this detection device and the block element shown in FIG. 35 is as follows. First, the upper electrode E10 functions as the Z-axis direction excitation means 143, and by applying a predetermined AC voltage between the upper electrode E10 and the lower electrode B, the central portion 11 can be vibrated in the Z-axis direction. it can. Further, the upper electrodes A11 and A12 function as the X-axis direction force detection means 151, and can detect the displacement of the central portion 11 in the X-axis direction based on the charges generated here. Further, the upper electrodes A13 and A14 are
It functions as the Y-axis direction force detection unit 152 and can detect the displacement of the central portion 11 in the Y-axis direction based on the electric charges generated here. After all, on the piezoelectric element 10,
Only by providing the five upper electrodes E10 and A11 to A14, the two-dimensional detection device shown in FIG. 35 can be realized.

FIG. 38 is a top view showing another structural example of a specific detecting device suitable for two-dimensional detection, and FIG.
[Fig. 3] is a side sectional view of the detection device taken along the XZ plane. The difference between the detection device shown in FIG. 38 and the detection device shown in FIG. 36 is that the positional relationship between the upper electrode for excitation and the upper electrode for force detection is reversed inside and outside. The correspondence between each upper electrode in this detection device and the block element shown in FIG. 35 is as follows. First, the upper electrode E20
Functions as the Z-axis direction excitation means 143, and the upper electrode E
By applying a predetermined AC voltage between the lower electrode 20 and the lower electrode B, the central portion 11 can be vibrated in the Z-axis direction. Further, the upper electrodes A21 and A22 function as the X-axis direction force detection means 151, and can detect the displacement of the central portion 11 in the X-axis direction based on the charges generated here. Further, the upper electrodes A23 and A24 function as the Y-axis direction force detecting means 152, and can detect the displacement of the central portion 11 in the Y-axis direction based on the charges generated here.

As described above, in the detection device which requires only two-dimensional detection, the overall manufacturing cost can be reduced by configuring the upper electrode with the minimum number.

§9. Of the capacitance type to which the present invention is applied
Detection Device As an example of the detection device to which the present invention is applied, in §2, a device using the piezoelectric element 10 has been described. As described above, the present invention can be applied to any detection device as long as it has a configuration as shown in the block diagram of FIG. 6, but here, for reference, ,
An example of the capacitive detection device to which the present invention is applied will be briefly described. This detecting device is disclosed in the international application PCT / JP93 / 00390 specification based on the Patent Cooperation Treaty.

FIG. 40 is a side sectional view of the capacitance type detection device 200. The main components of this detection device are the strain body 210, the vibrator 220, the pedestal 230, and the base substrate 2.
40 and a cover plate 250. FIG. 4 is a top view of the flexure element 210.
It is shown in FIG. As shown in FIG. 41, the flexure element 2
Reference numeral 10 is a square metal plate, and the lower surface of the metal plate is shown in FIG.
An annular groove as shown by the broken line is formed. FIG.
As clearly shown in the side sectional view of 0, the thickness of the flexure element 210 is small in the groove forming portion, and this portion has a flexible structure. Here, the flexure element 210 includes a central portion 211 existing inside the annular groove portion, a thin flexible portion 212 existing above the annular groove portion, and an outer side of the annular groove portion. The surrounding portion 213 and the existing peripheral portion 213 will be considered separately. The vibrator 220 is bonded to the bottom surface of the central portion 211. The vibrator 220 is a plate-shaped metal mass having a certain amount of mass, and acceleration and angular velocity are detected by a force based on acceleration acting on the vibrator 220 or a Coriolis force. On the other hand, on the bottom surface of the peripheral portion 213, a pedestal 230 is provided so as to surround the periphery of the vibrator 220.
Are joined together, and the bottom surface of this pedestal 230 is joined to the base substrate 240. After all, the vibrator 220 is suspended in the space surrounded by the pedestal 230. Further, a lid plate 250 is joined to the upper surface of the flexure element 210, and the lid plate 250 has a structure capable of securing a space inside as shown in the figure.

An upper electrode E0 and lower electrodes F1 to F5 are arranged in a space formed between the upper surface of the strain generating element 210 and the lower surface of the lid plate 250. Lower electrodes F1 to F5
41 is an electrode having a shape as shown in FIG. 41, which is fixed to the upper surface of the flexure element 210 at a position as shown. On the other hand, the upper electrode E0 is a disk-shaped electrode that can function as a common electrode facing all of the five lower electrodes F1 to F5, and is fixed to the lower surface of the lid plate 250. After all, five sets of capacitive elements are formed by the individual lower electrodes F1 to F5 and the common upper electrode E0.

As described above, the vibrator 220 has the pedestal 2
The flexible part 2 is suspended in the space surrounded by 30.
Since 12 is flexible, the vibrator 220 can move with some degree of freedom in the three XYZ directions shown in the figure. Therefore, if a predetermined AC voltage is applied between the electrodes, the vibrator 220 can be vibrated in a desired direction. For example, if electric charges of the same polarity are applied between the lower electrode F1 and the upper electrode E0, the repulsive force due to the Coulomb force acts and the distance between both electrodes widens. At this time, if charges of different polarities are simultaneously applied between the lower electrode F2 and the upper electrode E0, an attractive force due to the Coulomb force acts and the gap between both electrodes is narrowed. As a result, the oscillator 220
Causes a displacement in the positive direction of the X axis. If the relationship between the repulsive force and the attractive force is reversed, the vibrator 220 will be displaced in the negative direction of the X axis this time. Thus, if the positive and negative displacements are alternately performed along the X axis, the vibrator 220 vibrates along the X axis. Also,
By performing the same operation using the lower electrodes F3 and F4, it becomes possible to vibrate the vibrator 220 along the Y axis.
Further, if the lower electrode F5 is used, it is possible to vibrate along the Z-axis direction. That is, the lower electrode F5 and the upper electrode E0
If electric charges of the same polarity are given to and, the distance between both electrodes will widen due to the action of repulsive force. It will vibrate along the axial direction. As described above, this device includes the excitation means 141 to 143 in the respective axial directions shown in FIG.

On the other hand, this apparatus is also equipped with force detecting means 151 to 153 in the respective axial directions shown in FIG. Now, consider a case where a force based on acceleration or a Coriolis force acts on the vibrator 220. For example, when a force in the X-axis direction is applied, the vibrator 220 is displaced in the X-axis, so that the distance between the lower electrode F1 and the upper electrode E0, the distance between the lower electrode F2 and the upper electrode E0, Each will change. Further, when a force in the Y-axis direction is applied, the vibrator 220 is displaced in the Y-axis direction, so the distance between the lower electrode F3 and the upper electrode E0 and the distance between the lower electrode F4 and the upper electrode E0. , Will be changed respectively. Furthermore, when a force in the Z-axis direction is applied, the vibrator 220 is displaced in the Z-axis direction, so that the distance between the lower electrode F5 and the upper electrode E0 is changed. Such a change in the distance between the pair of electrodes facing each other changes the capacitance value of the capacitive element formed by the pair of electrodes. Therefore, if the change in the capacitance value of each capacitive element can be electrically detected, the displacement of the vibrator 220 can be detected,
As a result, the forces acting on the vibrator 220 in the respective axial directions can be detected.

As described above, this capacitive detection device 20
0 is the excitation means 141 to 143 in each axial direction shown in FIG.
Then, the present invention can be applied in the same way as the piezoelectric type detection device described in §2. In the illustrated capacitive detection device 200, the lower electrodes F1 to F5 serve as both the excitation means and the force detection means.
When the present invention is applied, it is preferable that the portion functioning as the excitation means and the portion functioning as the force detection means are physically separated as necessary.

Although the present invention has been described above based on several illustrated embodiments, the present invention is not limited to these embodiments and can be carried out in various modes other than this. In short, the basic idea of the present invention is to separate the synthetic force acting on the vibrator into the force f caused by the acceleration and the Coriolis force F caused by the angular velocity in the state where the vibrator is vibrated, and Is to be detected at the same time, and as long as it is included in the category of such a technical idea,
It may be carried out in any manner.

[0101]

As described above, according to the detection device of the present invention, the resultant force acting on the vibrating vibrator is separated into the force due to the acceleration and the Coriolis force due to the angular velocity, and the acceleration and the angular velocity are separated. Since both and can be detected at the same time, both acceleration and angular velocity can be detected with sufficient responsiveness.

[Brief description of drawings]

FIG. 1 is a perspective view showing a basic principle of a conventionally proposed one-dimensional angular velocity detecting device using Coriolis force.

FIG. 2 is an XYZ to be detected by the angular velocity detection device.
It is a figure which shows the angular velocity around each axis in a three-dimensional coordinate system.

FIG. 3 is a diagram illustrating a basic principle of detecting an angular velocity ωx about the X axis by using the detection device according to the present invention.

FIG. 4 is a diagram illustrating the basic principle of detecting the angular velocity ωy about the Y axis using the detection device according to the present invention.

FIG. 5 is a diagram illustrating the basic principle of detecting the angular velocity ωz about the Z axis using the detection device according to the present invention.

FIG. 6 is a block diagram showing components that perform angular velocity detection in the detection device according to the present invention.

FIG. 7 is a block diagram showing components that perform acceleration detection in the detection device according to the present invention.

FIG. 8 is a perspective view of a detection device according to a specific structural example of the present invention as seen obliquely from above.

9 is a perspective view of the detection device shown in FIG. 8 as viewed from diagonally below.

FIG. 10 is a top view of the detection device shown in FIG.

11 is a side sectional view of the detection device shown in FIG. 8 taken along the XZ plane.

FIG. 12 is a bottom view of the detection device shown in FIG.

13 is a diagram showing polarization characteristics of the piezoelectric element 10 in the detection device shown in FIG.

14 is a side sectional view showing a state in which a displacement Dx in the X-axis direction is induced with respect to the center of gravity P of the detection device shown in FIG.

15 is a side sectional view showing a state in which a displacement Dz in the Z-axis direction is induced with respect to the center of gravity P of the detection device shown in FIG.

16 is a side sectional view showing a state in which a force fx in the X-axis direction acts on the center of gravity P of the detection device shown in FIG.

17 is a side sectional view showing a state in which a force fz in the Z-axis direction acts on the center of gravity P of the detection device shown in FIG.

FIG. 18 is a table showing the polarities of charges generated in the upper electrodes A1 to A8 when the axial forces fx, fy, and fz based on acceleration act on the detection device shown in FIG.

19 is a circuit diagram showing an example of a detection circuit used in the detection device shown in FIG.

FIG. 20 is a flowchart showing the procedure of a general detection operation for a detection device to which the present invention is applied.

FIG. 21 shows a detection device to which the present invention is applied,
6 is a graph showing specific conditions of vibration applied to a vibrator, applied angular velocity, generated Coriolis force, and applied acceleration.

22 is a graph showing a synthetic force actually detected under the conditions shown in FIG.

23 is a graph showing a state where inflection points P1 to P9 are obtained in the graph of the combined force shown in FIG. 22.

24 is a graph showing a state where reference lines Q12 to Q89 are obtained based on the inflection points P1 to P9 obtained in FIG. 23.

25 is a reference line Q12 to Q89 obtained in FIG. 24;
It is a graph which shows the state which plotted the reference points m1-m8 on the top.

FIG. 26 is a graph showing a state in which a force f, which is a bias component of the resultant force, is extracted by connecting the reference points m1 to m8 obtained in FIG.

FIG. 27 is a graph showing a state of obtaining an angular velocity as an envelope E of the Coriolis force Fy.

FIG. 28 is a block diagram showing the basic configuration of the detection device according to the first example of the present invention.

29 is a flowchart showing a procedure of a detecting operation of the detecting apparatus according to the first example shown in FIG. 28. FIG.

FIG. 30 is a diagram illustrating another basic principle of detecting the angular velocity ωx about the X axis by using the detection device according to the present invention.

FIG. 31 is a diagram illustrating another basic principle of detecting the angular velocity ωy about the Y axis using the detection device according to the present invention.

FIG. 32 is a diagram illustrating another basic principle of detecting the angular velocity ωz about the Z axis using the detection device according to the present invention.

FIG. 33 is a block diagram showing a basic configuration of a detection device according to a second embodiment of the present invention.

34 is a flowchart showing a procedure of a detecting operation of the detecting apparatus according to the second embodiment shown in FIG.

FIG. 35 is a block diagram showing a basic configuration of a detection device according to a third embodiment of the present invention.

FIG. 36 is a top view showing the structure of a specific detection device suitable for two-dimensional detection.

37 is a side sectional view of the detection device shown in FIG. 36 taken along the XZ plane.

FIG. 38 is a top view showing the structure of another specific detection device suitable for two-dimensional detection.

39 is a side sectional view of the detection device shown in FIG. 38 taken along the XZ plane.

FIG. 40 is a side sectional view of a capacitive detection device 200 to which the present invention can be applied.

41 is a flexure element 210 in the detection device shown in FIG.
FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Piezoelectric element 11 ... Central part 12 ... Flexible part 13 ... Peripheral part 15 ... Annular groove 31-38 ... Q / V conversion circuit 41-43 ... Operation device 110 ... Transducer 111, 112 ... Piezoelectric element 120 ... Object 130 Vibrator 141 ... X-axis direction excitation means 142 ... Y-axis direction excitation means 143 ... Z-axis direction excitation means 151 ... X-axis direction force detection means 152 ... Y-axis direction force detection means 153 ... Z-axis direction force detection means 161 ... X-axis direction signal separating means 162 ... Y-axis direction signal separating means 163 ... Z-axis direction signal separating means 171 to 173 ... Acceleration calculating means 181 to 183 ... Angular velocity calculating means 200 ... Capacitive detecting device 210 ... Strain element 211 ... Central part 212 ... Flexible part 213 ... Peripheral part 220 ... Vibrator 230 ... Pedestal 240 ... Base substrate 250 ... Lid plate A, A1 to A8, A11 to A14, A21 to A24 ... Upper electrode B ... Lower electrode E ... Envelope E0, E1-E4, E10, E20 ... Upper electrode F1-F5 ... Lower electrode m1-m8 ... Reference point O ... Origin P ... Center of gravity P1-P9 ... Inflection point Q1-Q9 .. Compartment lines Q12 to Q89 ... Reference lines Tx, Ty, Tz ... Output terminals

Claims (7)

[Claims] 1. A device for detecting acceleration in a first axis direction and angular velocity about a second axis in a three-dimensional coordinate system, comprising: a vibrator having a mass; Excitation means for vibrating in the third axial direction of the system at a sufficiently high frequency that can be discriminated from the frequencies of the acceleration and the angular velocity to be detected, and the force in the first axial direction applied to the vibrator And a signal separating unit that separates a bias component and an amplitude component of the detection signal obtained by the force detecting unit, and the acceleration in the first axial direction is obtained based on the bias component. An apparatus for detecting both acceleration and angular velocity, comprising: an acceleration calculating device; and an angular velocity calculating device that obtains an angular velocity around the second axis based on the amplitude component. 2. A device for detecting acceleration in each axial direction of a first axis, a second axis, and a third axis in a three-dimensional coordinate system and an angular velocity around each axis, the vibrator having a mass. And a first exciting unit that vibrates the vibrator in the first axial direction at a sufficiently high frequency that can be identified with respect to frequencies of acceleration and angular velocity to be detected, and the vibrator, Second exciting means for vibrating in the second axial direction at a sufficiently high frequency identifiable with respect to the frequencies of the acceleration and the angular velocity to be detected; and the vibrator in the third axial direction. A third excitation means for vibrating at a sufficiently high frequency that can be identified with respect to the frequencies of the acceleration and the angular velocity to be detected, and a first detection means for detecting the force applied to the vibrator in the first axial direction. Force detection means, and added to the vibrator Second force detecting means for detecting the force in the second axial direction, third force detecting means for detecting the force in the third axial direction applied to the vibrator, and the first force Regarding the first detection signal obtained by the detection means, the first signal separation means for separating the bias component and the amplitude component, and the second detection signal obtained by the second force detection means, the bias component and the amplitude. A second signal separating means for separating a component, a third signal separating means for separating a bias component and an amplitude component of the third detection signal obtained by the third force detecting means, and the first A first acceleration calculating means for obtaining the acceleration in the first axial direction based on the bias component of the detection signal; and a second acceleration direction of the second axial direction based on the bias component of the second detection signal. Calculate acceleration 2 acceleration calculation means, a third acceleration calculation means for obtaining acceleration in the third axial direction based on a bias component for the third detection signal, and driving the second excitation means to drive the The vibrator is vibrated in the second axial direction, and the first
A first angular velocity calculation means for obtaining an angular velocity about the third axis based on the amplitude component of the detection signal of the above, and the vibrator is driven in the third axial direction by driving the third excitation means. Vibrating, the second obtained in this state
Second angular velocity calculation means for obtaining an angular velocity about the first axis based on the amplitude component of the detection signal of the above, and the first excitation means to drive the vibrator in the first axial direction. Vibrating, the third obtained in this state
An apparatus for detecting both acceleration and angular velocity, comprising: a third angular velocity calculating means for obtaining an angular velocity about the second axis based on an amplitude component of the detection signal. 3. A device for detecting acceleration in each axial direction of a first axis, a second axis, and a third axis in a three-dimensional coordinate system and an angular velocity around each axis, wherein the vibrator has a mass. And a first exciting unit that vibrates the vibrator in the first axial direction at a sufficiently high frequency that can be identified with respect to frequencies of acceleration and angular velocity to be detected, and the vibrator, Second excitation means for vibrating in the third axial direction at a sufficiently high frequency that can be identified with respect to the frequencies of the acceleration and angular velocity to be detected, and in the first axial direction applied to the vibrator Force detecting means for detecting force of the vibrator, second force detecting means for detecting force of the vibrator in the second axial direction, and force of the vibrator in the third axial direction. Third force detecting means for detecting the force of the hand, and the first force detecting hand A first signal separation means for separating a bias component and an amplitude component with respect to the first detection signal obtained by; and a bias component and an amplitude component with respect to the second detection signal obtained by the second force detection means. A second signal separating means for separating a bias component and an amplitude component with respect to a third detection signal obtained by the third force detecting means; A first acceleration calculating means for obtaining an acceleration in the first axial direction based on a bias component of a signal, and an acceleration in the second axial direction based on a bias component of the second detection signal. A second acceleration calculating means for obtaining; a third acceleration calculating means for obtaining acceleration in the third axial direction based on a bias component for the third detection signal; The first means obtained in this state by driving the excitation means to vibrate the vibrator in the third axial direction
A first angular velocity calculating means for obtaining an angular velocity about the second axis based on the amplitude component of the detection signal of the above, and the vibrator is driven in the first axial direction by driving the first exciting means. Vibrating, the second obtained in this state
The angular velocity about the third axis is obtained based on the amplitude component of the detection signal, and the third excitation means is driven to vibrate the vibrator in the third axis direction. And a second angular velocity calculating means for obtaining an angular velocity about the first axis based on the obtained amplitude component of the second detection signal. Both the acceleration and the angular velocity are detected. apparatus. 4. A device for detecting acceleration in a first axial direction and angular velocity about the first axis, and acceleration in a second axial direction and angular velocity about the second axis in a three-dimensional coordinate system. And a vibrator having a mass and a sufficiently high frequency capable of discriminating the vibrator in the third axis direction in the three-dimensional coordinate system from the frequencies of acceleration and angular velocity to be detected. An exciting means for vibrating the device, a first force detecting means for detecting a force applied to the vibrator in the first axial direction, and a first force detecting means for detecting a force applied to the vibrator in the second axial direction. 2 force detecting means, a first signal separating means for separating a bias component and an amplitude component of the first detection signal obtained by the first force detecting means, and a second force detecting means. The second detected signal that is Second signal separation means for separating a bias component and an amplitude component; first acceleration calculation means for obtaining the acceleration in the first axial direction based on the bias component for the first detection signal; Second acceleration calculating means for obtaining an acceleration in the second axial direction based on a bias component for the second detection signal, and the second axis based on an amplitude component for the first detection signal. A first angular velocity calculating unit for obtaining a peripheral angular velocity, and a second angular velocity calculating unit for obtaining an angular velocity about the first axis based on an amplitude component of the second detection signal. A device that detects both acceleration and angular velocity. 5. The apparatus according to any one of claims 1 to 4, wherein the signal separation means extracts each inflection point of the detection signal, and an intermediate position of two adjacent inflection points on the time axis, A reference point having a signal value obtained by averaging the signal values of the two inflection points is obtained, and a signal obtained by connecting the obtained reference points is used as a bias component, and a difference between the detection signal and the bias component is obtained. An apparatus for detecting both acceleration and angular velocity, characterized in that a corresponding signal is used as an amplitude component. 6. The apparatus according to claim 1, wherein the acceleration calculation means includes a bias component f of the detected force,
An apparatus for detecting both acceleration and angular velocity, characterized in that an acceleration α is obtained by applying an arithmetic expression f = m · α based on the mass m of the oscillator. 7. The apparatus according to any one of claims 1 to 4, wherein the angular velocity calculating means is estimated from the amplitude component F of the detected force, the mass m of the vibrator, and the operating state of the exciting means. A device for detecting both acceleration and angular velocity, characterized in that an angular velocity ω is obtained by applying an arithmetic expression F = 2 m · v · ω based on the instantaneous velocity v of the oscillator.