JP2000304542A - Angular velocity sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance detection sensitivity by a simple constitution despite of a small vibrator by spreading the selection range of material of the vibrator. SOLUTION: This sensor 100 is provided with a vibrator 1 on which free end a permanent magnet 4 is installed. The vibrator 1 is excited by piezoelectric bodies 2 and 3. When rotational force is added to the excited vibrator 1, vibration due to Coriolis force in accordance with the angular velocity Ω of rotation newly is developed in a vibrator 1. By detecting the amplitude of the vibration of the vibrator 1 due to Coriolis force with a detection coil 5, the angular velocity Ω is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an angular velocity sensor, and more particularly, to the detection of a Coriolis force acting in a direction orthogonal to the direction of vibration of an oscillating object when an angular velocity is applied to the object. And an angular velocity detection sensor for detecting the magnitude of the angular velocity.

[0002]

2. Description of the Related Art An angular velocity sensor is widely used as an autonomous traveling sensor of a car navigation system and a camera shake prevention sensor of a video movie. Among them, a piezoelectric gyro using a piezoelectric body for driving a vibrator and detecting a Coriolis force is widely used as a small and inexpensive angular velocity sensor (for example, "Basics of Piezoelectric Gyro Sensor Technology" Electronics Ceramics, 1991 1
0 issue).

FIG. 7 is a conceptual diagram showing a configuration of a conventional angular velocity sensor 200 comprising a piezoelectric gyro.

Referring to FIG. 7, a conventional angular velocity sensor 20
No. 0 includes a vibrator 1 on each surface of which a piezoelectric body 20, 21, 22, 23 is attached. The vibrator 1 includes a driving piezoelectric body 2
Due to 0, bending vibration occurs in the x direction in the figure. In this figure z
When an angular velocity Ω rotating around an axis is applied, Coriolis force acts in a direction orthogonal to the vibration direction, and vibration in the y direction in the drawing is excited. Since the Coriolis force generated in this case is proportional to the angular velocity Ω, the magnitude of the angular velocity Ω can be detected by detecting the amplitude of the vibration in the y direction by the piezoelectric bodies 22 and 23.

The piezoelectric body 21 can also be used for feedback of a drive signal.
21 can also be driven. Further, the quality of the angular velocity can be obtained by using only one of the piezoelectric bodies 22 and 23. By taking the difference or the sum of the outputs of the piezoelectric bodies 22 and 23, the null voltage generated by the drive vibration can be eliminated. Is also possible.

That is, the conventional angular velocity sensor 200
In this method, the distortion generated in the piezoelectric body due to the action of the Coriolis force is electrically converted by a vibrating gyroscope that uses the piezoelectric body for driving a vibrator and for detecting Coriolis, and is detected as a voltage.

In general, in such a vibrating gyroscope, it is known that the amplitude of the vibration in the y direction due to the Coriolis force is inversely proportional to the driving frequency. On the other hand, the resonance frequency of the vibrator is inversely proportional to the square of the length of the vibrator. Therefore, when the size of the vibrator is reduced, the resonance frequency increases. Therefore, the conventional angular velocity sensor using the vibrating gyroscope has a disadvantage that when the vibrator is downsized, the detection sensitivity is reduced, and it has been difficult to achieve both the downsizing of the device and the detection sensitivity.

Further, since the angular velocity sensor 200 detects the strain generated in the vibrator by the piezoelectric body, there is a problem of a temperature drift of the piezoelectric body due to a large thermal expansion coefficient of piezoelectric ceramics used for the piezoelectric body, Due to the difficulty in securing the mounting position accuracy of the piezoelectric body, there is a high possibility that the required detection accuracy cannot be sufficiently secured.

In order to solve such a drawback, a method has been proposed in which vibration in the y-direction due to Coriolis force is detected by electromagnetic induction. In this method, the influence of the frequency on the amplitude of the vibration is reduced by measuring the Coriolis force not by the displacement of the vibrator but by the time change of the displacement.

For example, Japanese Patent No. 2742916 proposes a method for detecting vibration caused by Coriolis force by electromotive force generated by a time change of a gap between a magnetic pole portion having a detection coil and a vibrator made of a soft magnetic material. (Hereinafter referred to as conventional technology 1).

Further, Japanese Patent Publication No. 6-15974 discloses that
There is also a method of detecting a vibration component generated perpendicular to the driving plane by a coil, in which a pair of branches forming an oscillator is magnetized so as to have two separate magnetic systems including a north pole and a south pole. It has been proposed (hereinafter referred to as conventional technology 2).

[0012]

However, in the angular velocity sensor of the prior art 1, since the vibrator needs to have a characteristic of being attracted to the magnet, the vibrator cannot be made of a piezoelectric material. For example, there is a problem that a selection range of materials is narrowed.

In the angular velocity sensor according to the prior art 2,
Since the vibrator is made of a permanent magnet material, the prior art 1
As in the case of (1), there is a problem that the selection range of the material of the vibrator is narrowed, and since it is magnetized so as to include the N pole and the S pole therein, the means for magnetizing the vibrator becomes complicated, Therefore, it is difficult to provide an N pole and an S pole. This poses a further problem when miniaturization of the angular velocity sensor is considered.

Further, in the prior arts 1 and 2,
Since an electromagnetic driving method is used as the driving means of the vibrator, there is a problem that a magnetic field from the driving coil affects the detection coil as noise. If the drive unit and the detection unit are arranged close to each other with the miniaturization of the device, the influence on the noise detection accuracy will be further increased.

The present invention has been made to solve such problems, and an object of the present invention is to provide a vibrator with a wide selection range of materials under a simple configuration. An object of the present invention is to provide an angular velocity sensor capable of sufficiently securing detection sensitivity even with a downsized vibrator.

[0016]

According to a first aspect of the present invention, there is provided an angular velocity sensor comprising: a vibrator having one end fixed and a free end vibrating; a permanent magnet provided at a movable portion of the vibrator; Driving means for vibrating in a predetermined direction, a first detection coil for detecting a change in a magnetic line of force caused by displacement of the permanent magnet in a direction orthogonal to the predetermined direction, and an induction coil generated in the detection coil. Voltage measuring means for detecting a voltage.

The angular velocity sensor according to the second aspect is the first aspect.
The angular velocity sensor according to claim 1, wherein the permanent magnet is provided such that a magnetization direction is orthogonal to a predetermined direction, and the first detection coil is configured such that a direction of a coil axis is parallel to a magnetization direction of the permanent magnet. Provided.

According to a third aspect of the present invention, there is provided an angular velocity sensor.
The angular velocity sensor according to claim 1, wherein the permanent magnet is provided such that a magnetization direction is one of a predetermined direction and a longitudinal direction of the vibrator, and the first detection coil is provided near both poles of the permanent magnet. Including a pair of coils arranged, each of the pair of coils is provided such that the direction of the coil axis is orthogonal to a predetermined direction.

According to the fourth aspect of the present invention, there is provided an angular velocity sensor according to the first aspect.
The angular velocity sensor according to claim 1, wherein the permanent magnet is provided such that a magnetization direction is one of a predetermined direction and a longitudinal direction of the vibrator, and the first detection coil has a coil axis having a magnetization direction of the permanent magnet. It is provided so as to be parallel to the direction.

The angular velocity sensor according to the fifth aspect is the first aspect.
5. The angular velocity sensor according to any one of items 1 to 4, wherein the driving unit includes a piezoelectric element mounted on the vibrator.

According to a sixth aspect of the present invention, there is provided an angular velocity sensor according to the fifth aspect.
The angular velocity sensor according to claim 1, further comprising a second detection coil for detecting a change in a line of magnetic force caused by displacement of the permanent magnet in a predetermined direction, wherein the driving unit outputs an output of the second detection coil. The vibrator is excited by using it as a feedback signal.

According to a seventh aspect of the present invention, there is provided an angular velocity sensor according to the first aspect.
7. The angular velocity sensor according to any one of claims 1 to 6, wherein
Has a core.

The angular velocity sensor according to the eighth aspect is the sixth aspect.
The angular velocity sensor according to claim 1, wherein the second detection coil has a core.

[0024]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the drawings, the same reference numerals indicate the same or corresponding parts.

[Embodiment 1] FIG. 1 is a perspective view of an angular velocity sensor 100 according to Embodiment 1 of the present invention, and FIG. 2 is a plan view thereof.

Referring to FIGS. 1 and 2, the angular velocity sensor 100 includes a vibrator 1, a driving piezoelectric body 2 and a feedback piezoelectric body 3 attached to the vibrator 1, and a vicinity of a free end of the vibrator 1. , A detection coil 5 provided close to the permanent magnet 4, and a voltage measurement circuit (not shown) for measuring an induced voltage generated in the detection coil.

The vibrator 1 is excited by a driving piezoelectric body 2 and a feedback piezoelectric body 3. Therefore, the material of the vibrator 1 is not limited to a magnetic material. Desirably, a constant elastic metal (for example, Sumitomo Special Metals, EL-3) or the like can be suitably used so that the vibration characteristics do not change with a change in the ambient temperature.

PZT (Pb (Zr, Ti) O 3) or BaTiO 3 is used as the driving piezoelectric element 2 and the feedback piezoelectric element 3.
For example, a piezoelectric ceramic such as 3 can be suitably used.
When the material of the vibrator 1 is a piezoelectric body, the vibrator 1 can be excited by providing an electrode instead of the piezoelectric bodies 3 and 4.

As the permanent magnet 4, it is possible to use a rare earth magnet (for example, NEOMA MAX made by Sumitomo Special Metals), a SmCo magnet, or a permanent magnet other than the rare earth magnet.

The detection coil 5 may be formed by winding a conductor having a selected material and wire diameter in a predetermined shape and number of turns according to the required detection sensitivity and cost.

Although the center of the detection coil may be hollow, the sensitivity of the detection coil 5 can be improved by providing a core made of a high magnetic permeability material such as sendust or permalloy at the center. .

Further, in FIG. 5, the magnetic pole N-pole of the permanent magnet 4 and the detecting coil 5 face each other, but the magnetic pole facing the detecting coil 5 may be the S-pole. Also,
The distance between the detection coil 5 and the permanent magnet 4 may be determined according to the required detection sensitivity, the material of the permanent magnet and the detection coil, etc., but is generally about 0.05 to 3 mm. It is enough if it is in the range. In FIG. 1, the shape of the permanent magnet 4 is a quadratic prism, but it is of course possible to use another shape such as a columnar or polygonal column.

In the angular velocity sensor 100, the vibrator 1
Is excited in the x direction by the driving piezoelectric body 2. The feedback piezoelectric element 3 outputs a feedback signal for driving at the resonance frequency of the vibrator. When an angular velocity Ω rotating about the z-axis is applied to the vibrator 1 excited in the x direction, a Coriolis force proportional to Ω is generated in the y direction, and as a result, the vibrator 1 also vibrates in the Y direction.

Since the vibrator 1 is provided with the permanent magnet 4, the magnetic flux penetrating the detecting coil 5 changes, and the time change of the magnetic flux changes the electromotive force of electromagnetic induction according to the magnitude of the angular velocity Ω. The electromotive force generated in the detection coil 5 is detected as a voltage signal by a voltage measurement circuit. Thus, the angular velocity Ω is detected.

Here, the displacement Xd in the driving direction of the vibrator 1
Is represented by the following equation, where A is the amplitude, ω is the angular frequency of the vibration, and t is the time.

Xd = A · sin (ω · t) The vibration velocity Vx in the driving direction is given by Vx = A · ωcos (ω · t) by differentiating Xd, and the Coriolis force Fc is expressed by the following equation. .

Fc = −2 · m · Vx · Ω = M · α (m is the oscillating mass, α is the acceleration) By integrating the acceleration α twice, the displacement Yd due to the Coriolis force is obtained, Yd = 2A ( Ω / ω) cos (ω · t).

Assuming that the length of one side of the vibrator is a and the total length of the vibrator is L, if the cross section is polygonal, the resonance frequency ω
Is proportional to a and inversely proportional to the square of L. Further, assuming that the force from the piezoelectric body is P, the drive amplitude A of the vibrator is proportional to the third power of P and L and inversely proportional to the fourth power of a.
The force P from the piezoelectric body is proportional to the area of the piezoelectric body. Even if the size of the vibrator changes, assuming that the ratio between the size of the vibrator and the size of the piezoelectric body is equal, the Coriolis force P is a -It is proportional to L.

Therefore, the drive amplitude A is inversely proportional to the third power of a and is proportional to the fourth power of L. As described above, the displacement Yd due to the Coriolis force is proportional to the sixth power of Ω and L, and is inversely proportional to the fourth power of a.

On the other hand, the vibration velocity Vy excited by the Coriolis force is obtained by integrating α once, and Vy = −
2A · Ω · cos (ω · t).

Since the drive amplitude A is inversely proportional to the cube of a and is proportional to the fourth power of L, the vibration velocity Vy excited by the Coriolis force is inversely proportional to the cube of a and proportional to the fourth power of L. I do.

Based on the above results, the output of the angular velocity sensor 100 of the present invention for detecting the Coriolis force and the conventional angular velocity sensor 200 of the piezoelectric gyro for detecting the Coriolis force when the length of the vibrator is changed. The calculation result of the relative change of the will be described.

FIG. 3 is a diagram comparing the relationship between the change in the length of the vibrator and the change in the amplitude of the vibrator between the method for detecting the Coriolis force according to the present invention and the method using the piezoelectric gyro.

Referring to FIG. 3, the vertical axis relatively shows the change in the amplitude of vibration generated in the vibrator when the length of the vibrator changes under the action of a constant Coriolis force. Things. On the other hand, the horizontal axis represents the change in the length of the vibrator as a relative value.

The amplitude displacement Yd caused by the Coriolis force
Decreases sharply as the length of the vibrator decreases, but since the decrease in the vibration velocity excited by the Coriolis force is smaller than the decrease in the displacement itself, the present invention has a greater effect than the conventional piezoelectric gyro method. It can be understood that the method of detecting the Coriolis force by the method can suppress the lowering of the detection sensitivity.

In the angular velocity sensor 100, since the permanent magnet 4 is excited in the x direction, strictly speaking, the magnetic flux passing through the detection coil may change due to the vibration in the x direction. This change is negligible because it is very small compared to the displacement of the magnetic flux due to directional vibration.

Further, in the angular velocity sensor 100, a cantilever bar type bi-resonant vibrator is used as the vibrator.
As the shape of the vibrator, a tuning fork type, an H-type vibrator, or the like can be suitably used.

As described above, in the angular velocity sensor 100 according to the first embodiment of the present invention, since the vibrator is provided with the permanent magnet, it is not necessary to set magnetic restrictions on the material of the vibrator. The selection range can be widened. In addition, since the positional relationship between the permanent magnet and the coil can be easily adjusted, an angular velocity sensor having high detection sensitivity can be obtained. Further, as a driving means of the vibrator,
Since the piezoelectric body is used without using the electromagnetic driving method, it is possible to prevent an unnecessary magnetic field other than the permanent magnet provided on the vibrator from adversely affecting the detection coil. Thus, the Coriolis force can be detected with low noise, and an angular velocity sensor having high detection sensitivity can be obtained.

[Modification of First Embodiment] In the first embodiment, the configuration in which one block-shaped permanent magnet 4 is attached to the tip of the vibrator 1 has been described. It is also possible to adopt a configuration.

FIG. 4 is a perspective view of an angular velocity sensor 110 according to a modification of the first embodiment of the present invention.

Referring to FIG. 4, the angular velocity sensor 110
Compared to the angular velocity sensor 100 of the first embodiment, the thin plate-like permanent magnets 4 attached to both sides near the free end of the vibrator instead of the permanent magnets 4 attached to the tip of the vibrator
a and 4b.

As described above, even if the permanent magnet is arranged on the side surface of the vibrator, an angular velocity sensor capable of obtaining the same effect can be configured.

By providing the thin plate-like permanent magnets 4a and 4b symmetrically on both sides of the vibrator, the balance of the vibrator 1 can be improved.

In the angular velocity sensor 110, it is sufficient if the detection coil 5 is provided for either one of the permanent magnets 4a and 4b, and the Coriolis coil is formed by the same method as the angular velocity sensor 100 of the first embodiment. The angular velocity can be detected by detecting the amplitude of the vibration caused by the force.

[Second Embodiment] FIG. 5 is a perspective view of an angular velocity sensor 120 according to a second embodiment of the present invention.

Referring to FIG. 5, the angular velocity sensor 120
Compared to the angular velocity sensor 100 of the first embodiment, the point that the magnetization direction of the permanent magnet 4 is provided so as to coincide with the z direction, which is the longitudinal direction of the vibrator 1, Are provided with a pair of detection coils 5a and 5b provided opposite to two magnetic poles so as to coincide with the y direction. The other configurations are the same as those of angular velocity sensor 100, and therefore description thereof will not be repeated.

In the angular velocity sensor 120, as in the case of the angular velocity sensor 100, the vibrator 1 is driven by a piezoelectric body for driving.
The piezoelectric element for feedback 3 is excited in the direction, and outputs a feedback signal for driving the vibrator at the resonance frequency.

When the angular velocity Ω about the z-axis is added, the angular velocity Ω
Is generated in the y direction, and as a result, the vibrator 1 vibrates in the y direction. Since the permanent magnet 4 is provided at the upper end of the vibrator 1, the number of magnetic fluxes passing through the detection coils 5a and 5b changes, and the angular velocity Ω is detected by detecting the induced electromotive force.
Can be detected.

In the angular velocity sensor 120, since the directions of the magnetic flux passing through the detection coils 5a and 5b are opposite to each other, the detection coils 5a and 5b are connected so that the winding directions of the coils are opposite. By connecting, it is possible to increase the output. At this time, the electromagnetic noise from the outside generates an electromotive force having the same phase in the detection coils 5a and 5b. However, if the two coils are connected so that the winding directions are opposite, as described above, the external noise is generated. The effect of the electromotive force due to noise can be eliminated.

Therefore, the angular velocity sensor 120 can detect the Coriolis force with lower noise. In the angular velocity sensor 120, a pair of detection coils 5a and 5b are provided on one side of the permanent magnet. However, by additionally arranging a pair of detection coils on the other side of the permanent magnet, It is possible to further increase the output.

In FIG. 5, the permanent magnet 4 has a configuration in which the magnetization direction is provided in the z direction, which is the longitudinal direction of the vibrator, but the magnetization direction is changed to the x direction, which is the excitation direction of the vibrator 1. It is also possible to provide them so as to match.

In the angular velocity sensor 120 as well, a cantilever bar type bi-resonant vibrator was used as the vibrator, but a tuning fork type, an H-type vibrator or the like can be suitably used as the vibrator.

[Embodiment 3] FIG. 6 is a perspective view of an angular velocity sensor 130 according to Embodiment 3 of the present invention.

Referring to FIG. 6, the angular velocity sensor 130 of the third embodiment is different from angular velocity sensor 100 of the first embodiment in that the coil axis is replaced by vibrator 1 instead of detecting coil 5.
The point that the detection coils 5c and 5d provided so as to match the x direction which is the excitation direction is different from the point where the magnetization direction of the permanent magnet 4 is provided so as to match the x direction.

The detection coil 5c is arranged on the y direction side of the permanent magnet 4, and the other detection coil 5d is arranged on the x direction side of the permanent magnet 4. Other configurations are the same as those of angular velocity sensor 100, and thus detailed description will not be repeated.

In the angular velocity sensor 130, since the detection coil 5c can detect the vibration of the permanent magnet 4 in the x direction, the detection output can be used as a feedback signal for driving the piezoelectric body 2. This eliminates the need for the feedback piezoelectric body 3 that generates a feedback signal for driving the vibrator at the resonance frequency, and makes it possible to reduce the number of piezoelectric bodies attached to the vibrator.

Of course, also in the angular velocity sensor 130, the piezoelectric body 3 for feedback can be provided as a backup similarly to the angular velocity sensor 100 and the like.

As shown in FIG. 6, even if the detection coil 5d is arranged on the y-direction side of the permanent magnet 4 so that its coil axis coincides with the x-direction, the vibration due to the Coriolis force generated in the y-direction is similarly affected. It is possible to detect.

In addition to the circular shape shown in FIG. 6, the sectional shape of the detection coil 5d is rectangular or semi-circular so as to conform to the surface shape of the permanent magnet 4.
, And sensitivity can be expected to increase.

The same arrangement as that of the detection coil 5d of the angular velocity sensor 130 is used in the first and second embodiments.
It is also possible to apply to the angular velocity sensors 100, 110, and 120 in.

FIG. 6 shows an example in which the permanent magnet 4 is provided such that the magnetization direction coincides with the x direction which is the excitation direction of the vibrator, but the magnetization direction of the permanent magnet 4 is the longitudinal direction of the vibrator. It is also possible to provide the z direction.

Further, in the third embodiment, one detection coil 5d is arranged to detect vibration in the y direction. However, similar to the second embodiment, the other detection coil 5d is provided on the other side of the permanent magnet. Further, the output can be increased by additionally using a detection coil.

In the first to third embodiments, one permanent magnet 4 is provided for the vibrator 1. However, it is needless to say that a plurality of permanent magnets can be provided. It is also possible to provide a coil. Furthermore, a desired angular velocity sensor can be obtained by combining the configurations described in the first to third embodiments as needed.

[0074]

The angular velocity sensor according to the first, second, and fourth aspects detects the generation of the Coriolis force by a change in the line of magnetic force generated by the permanent magnet provided at the movable part of the vibrator. It is possible to obtain an angular velocity sensor that can be widely selected without being limited to the body and that has a small decrease in detection sensitivity even if the size is reduced.

In the angular velocity sensor according to the third aspect, the change in the magnetic field lines is detected by the detecting coils provided in the pair. Therefore, in addition to the effect of the angular velocity sensor according to the first aspect, the output can be increased or the external force can be increased. The effect of electromagnetic noise can be eliminated, and the detection sensitivity can be increased.

In the angular velocity sensor according to the fifth aspect, since the vibrator is excited by the piezoelectric element, an unnecessary magnetic field generated by means other than the permanent magnet is prevented from affecting the detection coil. In addition to the effects of the angular velocity sensor described above, an angular velocity sensor with low noise and high detection sensitivity can be obtained.

In the angular velocity sensor according to the sixth aspect, the vibration in a predetermined direction of the vibrator detected by the detecting coil is used as a feedback signal, so that in addition to the effect of the angular velocity sensor according to the fifth aspect, a piezoelectric element is provided. Can be reduced.

In the angular velocity sensor according to the seventh and eighth aspects, since the detection coil has a core, the detection sensitivity of the detection coil can be increased, and the effect of the angular velocity sensor according to the first to sixth aspects is improved. In addition, the detection sensitivity can be further improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of an angular velocity sensor 100 according to Embodiment 1 of the present invention.

FIG. 2 is a plan view of the angular velocity sensor 100 according to Embodiment 1 of the present invention.

FIG. 3 is a diagram comparing the relationship between the change in the length of the vibrator and the change in the amplitude of the vibrator between the method for detecting a Coriolis force according to the present invention and the method for detecting using a piezoelectric gyro.

FIG. 4 is a perspective view of an angular velocity sensor 110 according to a modification of the first embodiment of the present invention.

FIG. 5 is a perspective view of an angular velocity 120 according to the second embodiment of the present invention.

FIG. 6 is a perspective view of an angular velocity 130 according to the third embodiment of the present invention.

FIG. 7 is a conceptual diagram showing an overall configuration of a conventional angular velocity sensor 200.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vibrator 2 Driving piezoelectric body 3 Feedback piezoelectric body 4, 4a, 4b Permanent magnet 5, 5a, 5b, 5c, 5d Detection coil

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tomohisa Koda 22-22, Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Inside (72) Inventor Toru Kira 22-22, Nagaike-cho, Abeno-ku, Osaka-shi, Osaka F term (reference) 2F105 AA02 AA08 BB03 BB12 BB13 CC06 CD01 CD06

Claims (8)

[Claims] A vibrator having one end fixed and a free end vibrating; a permanent magnet provided at a movable portion of the vibrator; and a driving unit for vibrating the vibrator in a predetermined direction. A first detection coil for detecting a change in a line of magnetic force caused by a displacement of the permanent magnet in a direction orthogonal to the predetermined direction; and a voltage measurement for detecting an induced electromotive voltage generated in the detection coil. Angular velocity sensor comprising: 2. The permanent magnet is provided such that a magnetization direction is orthogonal to the predetermined direction. The first detection coil has a coil axis direction parallel to the magnetization direction of the permanent magnet. The angular velocity sensor according to claim 1, wherein 3. The permanent magnet is provided such that a magnetization direction is one of the predetermined direction and a longitudinal direction of the vibrator. The first detection coil is provided with two poles of the permanent magnet. The angular velocity sensor according to claim 1, further comprising a pair of coils disposed in the vicinity, wherein each of the pair of coils is provided such that a direction of a coil axis is orthogonal to the predetermined direction. 4. The permanent magnet is provided such that a magnetization direction is one of the predetermined direction and a longitudinal direction of the vibrator. The first detection coil has a coil axis of the permanent magnet. The angular velocity sensor according to claim 1, wherein the angular velocity sensor is provided so as to be parallel to the magnetization direction. 5. The angular velocity sensor according to claim 1, wherein the driving unit includes a piezoelectric element mounted on the vibrator. 6. The apparatus according to claim 6, further comprising a second detection coil for detecting a change in a magnetic line of force caused by the displacement of the permanent magnet in the predetermined direction, wherein the driving unit outputs an output of the second detection coil. To excite the vibrator by using as a feedback signal,
The angular velocity sensor according to claim 5. 7. The angular velocity sensor according to claim 1, wherein the first detection coil has a core. 8. The angular velocity sensor according to claim 6, wherein the second detection coil has a core.