JP2009115559A - Angular velocity sensor and electronic device equipped with angular velocity sensor - Google Patents

Abstract

An angular velocity sensor capable of detecting an angular velocity of a reversed posture, having a simple configuration, having a small weight and manufacturing cost, good maintainability, and the angular velocity sensor, as in the case where the posture of a gyro element is reversed. Providing equipped electronic equipment.
A planar element portion 3, a plurality of electrodes 4a to 4d arranged in a direction around the center of the element portion 3, and an alternating current that causes the element portion 3 to primarily vibrate by applying an alternating voltage to a predetermined electrode. Electric power source 11, detection means 13 for detecting an electric signal generated at a predetermined electrode, switching means 15 for switching the connection state of AC power supply 11 and detection means 13 to electrodes 4a to 4d, and electric signal detected by detection means 13 There is provided an angular velocity sensor provided with calculation means 16 for detecting an angular velocity based on a change in the magnitude of the angular velocity.
[Selection] Figure 1

Description

  The present invention relates to an angular velocity sensor and an electronic device including the angular velocity sensor.

The angular velocity detected by the angular velocity sensor includes a bias component. The bias component is called zero point output or offset, and is caused by various factors such as asymmetry of the gyro element provided in the angular velocity sensor, circuit characteristics, temperature influence, and the like. The angular velocity Y detected by the angular velocity sensor including such a bias component and the true angular velocity X (the angular velocity of the rotational motion itself that is the detection target of the angular velocity) have a relationship represented by the following equation (1) ′.
Y = AX + B (A: coefficient, B: bias component) (1) ′
B = B ₁ + B ₂ + B ₃ +... + B _n (B _{1 to} B _n : bias components of various factors)

  In order to calculate the true angular velocity X from the angular velocity Y detected by the angular velocity sensor, the following method may be used. In this method, the angular velocity Y1 detected when the gyro element 101 is in the non-inverted attitude (see FIG. 14A), the gyro element 101 is in the inverted attitude (see FIG. 14B), and the gyro element This is a method of calculating the true angular velocity using the angular velocity Y2 detected when the true angular velocity 101 is the same as that when the angular velocity Y1 is detected.

The relationship between the angular velocity Y1 and the true angular velocity X is expressed by the following equation (2) ′ and FIG.
Y1 = AX + B _P (2) ′ (B _P : Bias component when in non-inverted posture)
On the other hand, the relationship between the aforementioned angular velocity Y2 and the true angular velocity X is expressed by the following equation (3) ′ and FIG.
Y2 = −AX + B _N (3) ′ (B _N : bias component in the reversed posture)

Bias component, since it can be regarded as unchanged by physical inversion of the gyro element 101, B _N equals equation (2) 'B _P and equation (3)', from equation (2) '(3) Subtracting 'and solving for X yields the following equation (4)'.
X = (Y1-Y2) / 2A (4) ′

  However, in order to calculate the true angular velocity by the above-described method, the angular velocities in the non-inverted posture and the inverted posture are required. For example, a gyro element reversing mechanism described in Patent Document 1 is used. It is necessary to provide the angular velocity sensor. However, when such an inversion mechanism is provided in the angular velocity sensor, the angular velocity sensor has a complicated structure, a large weight and a high manufacturing cost, and low maintainability.

  On the other hand, Patent Document 2 discloses a gyro sensor that detects an angular velocity when the gyro element is in a reversed posture without using a gyro element reversing mechanism.

The gyro sensor disclosed in Patent Document 2 detects the angular velocity when the gyro element is in the inverted posture by inverting the detection polarity of the angular velocity when the gyro element is in the non-inverted posture. At the angular velocity with the detected polarity reversed, the bias component generated by the configuration of the electric circuit among the bias components included in the angular velocity is the same size as when the attitude of the gyro element is reversed. However, since the attitude of the gyro element is not reversed even if the detection polarity is reversed, the positional relationship between the components constituting the gyro element is not reversed. For this reason, since a part of the bias component included in the angular velocity with the detected polarity reversed is different from that when the posture of the gyro element is reversed, the bias included in the angular velocity Y2 in the reversed posture detected by the technique of Patent Document 2. The component is different from the bias component included in the angular velocity Y1 in the non-inverted posture. Thus, if the bias components included in the angular velocities Y1 and Y2 are different, the above equation (4) ′ cannot be calculated from the above equations (2) ′ and (3) ′. Therefore, the true angular velocity X cannot be calculated by the method described above using the technique of Patent Document 2.
JP 2006-177909 A JP 2006-64613 A

  The present invention has a simple configuration, a low weight and manufacturing cost, good maintainability, and an angular velocity sensor capable of detecting the angular velocity of the reversed posture, as well as the case where the posture of the gyro element is reversed, and the angular velocity sensor It is an object to provide an electronic device including

  As a first means, the present invention provides a planar element portion, and a primary electrode and a second electrode disposed on the element portion along the direction around the center of the element portion, or disposed opposite to the element portion. A secondary electrode, and the primary electrode is arranged at intervals of (360 ° / n (n is an integer of 2 or more)) in a direction around the center of the element portion, and the secondary electrode It is arranged at a position away from the electrode in the direction around the center of the element part (360 ° × 1 / 4n), and by the electrostatic force or electromagnetic force generated between the element part and the primary electrode or the secondary electrode, An angular velocity sensor for generating in-plane cosnθ mode primary vibration in the element unit, connected to one of the primary electrode and the secondary electrode, and applying an AC voltage to the connected electrode An AC power source that generates primary vibration in the cosnθ mode in the element unit, and a detection that detects the magnitude of an electrical signal that is connected to the other of the primary electrode and the secondary electrode and that is generated at the connected electrode And a connection state of the AC power supply and the detection means with respect to the primary electrode and the secondary electrode, wherein the AC power supply is connected to the primary electrode, and the detection means is connected to the secondary electrode. A switching means for switching between a state and a second state in which the AC power source is connected to the secondary electrode and the detection means is connected to the primary electrode; and a change in the magnitude of an electrical signal detected by the detection means Based on the above, an angular velocity sensor is provided, comprising an arithmetic means for calculating an angular velocity in the first state and the second state.

  The angular velocity sensor according to the first means detects angular velocities in the first state and the second state by the following calculation. The AC power source applies an AC voltage to the electrode to which the AC power source is connected, and generates primary vibration in the in-plane cosnθ mode in the element portion. When the element portion performs a rotational motion around the normal direction of the element portion while the element portion is performing a primary vibration, a secondary vibration having a magnitude corresponding to the angular velocity of the rotational motion is generated in the element portion. This secondary vibration is an in-plane cosnθ mode vibration in which the maximum stretching direction is different from the primary vibration (360 ° × 1 / 4n). In both the first state and the second state, the detecting means is an electrode arranged at a position (360 ° × 1 / 4n) away from the electrode to which the AC power source is connected in the direction around the center of the element portion. It is connected. Therefore, in both the first state and the second state, an electrical signal having a magnitude corresponding to the secondary vibration is generated at the electrode to which the detection means is connected. The angular velocity sensor according to the first means calculates the angular velocity based on the magnitude of the electrical signal detected by the detection means. Therefore, the angular velocity sensor according to the first means can detect the angular velocity in the first state and the second state.

  The angular velocity sensor according to the first means switches the connection state of the AC power source and the detection means with respect to the primary electrode and the secondary electrode from the first state to the second state or from the second state to the first state. The positional relationship between the electrodes connected to the power source and the detection means can be made the same as that when the posture of the element portion and the primary to secondary electrodes are physically reversed. Therefore, the angular velocity sensor according to the first means can detect the angular velocity of the reversed posture, even when the posture of the element unit and the primary and secondary electrodes are not physically reversed, as in the case of physically reversed. Can do. Thus, since the angular velocity sensor according to the first means can detect the angular velocity in the reversed posture without using the reversing mechanism, the angular velocity in the reversed posture is equivalent to that when physically reversed. Can be detected, the configuration is simple, the weight and manufacturing cost are small, and the maintenance is good.

  As a second means, the present invention provides a planar element portion, a primary electrode disposed on the element portion along a direction around the center of the element portion, or a second electrode disposed opposite to the element portion. A primary electrode, and the primary electrode is arranged at 1 to (n-1) positions among n positions located at 360 ° / n intervals in a direction around the center of the element portion, and The secondary electrode is disposed at a position (360 ° × 1 / 4n) away from each primary electrode in a direction around the center of the element portion, and between the element portion and the primary electrode or the secondary electrode. An angular velocity sensor for generating in-plane cosnθ mode primary vibration in the element portion by the generated electrostatic force or electromagnetic force, the electrode being connected to any one of the primary electrode and the secondary electrode An AC voltage is applied, and an AC power source is generated to cause the element portion to generate primary vibrations in the in-plane cosnθ mode at the natural frequency of the in-plane cosnθ mode, and connected to either one of the primary electrode and the secondary electrode. Detecting means for detecting the magnitude of an electric signal generated in the connected electrode; and the connection state of the AC power source and the detecting means with respect to the primary electrode and the secondary electrode. Switching between a first state in which the detection means is connected to the secondary electrode and a second state in which the AC power source is connected to the secondary electrode and the detection means is connected to the primary electrode. And an calculating means for calculating an angular velocity in the first state and the second state based on a change in the magnitude of the electric signal detected by the detecting means. To provide a degree sensor.

  In the angular velocity sensor according to the second means, the positions where the primary and secondary electrodes are arranged are fewer than n. The angular velocity sensor according to the second means applies an AC voltage to the primary electrode or the secondary electrode arranged at a position smaller than n, and vibrates the element portion at the natural frequency of the in-plane cosnθ mode, A primary vibration in the in-plane cosnθ mode is generated in the element portion. As described above, even in the angular velocity sensor according to the second means, the primary vibration in the in-plane cosnθ mode can be generated in the element portion. Therefore, the angular velocity sensor according to the second means is the angular velocity according to the first means. Similar to the sensor, the angular velocity can be detected. In addition, the angular velocity sensor according to the second means, like the angular velocity sensor according to the first means, switches the connection state of the AC power supply and the detection means to the primary electrode and the secondary electrode, thereby switching the AC power supply and the detection means. The positional relationship of the connected electrodes can be made the same as when the element portion and the primary and secondary electrodes are physically reversed. Therefore, the angular velocity sensor according to the second means can detect the angular velocity in the reversed posture without using the reversing mechanism, similarly to the angular velocity sensor according to the first means, so that the configuration is simple. , Weight and manufacturing cost are small and maintainability is good.

The present invention provides, as a third means, a planar element portion and a primary electrode disposed on the element portion or opposed to the element portion along a direction around the center of the element portion, A secondary electrode, a tertiary electrode, and a quaternary electrode, wherein the primary electrode is arranged at an interval of (360 ° / n (n is an integer of 2 or more)) in a direction around the center of the element portion, The secondary electrode is disposed at a position (360 ° × 1 / 4n) away from each primary electrode in a direction around the center of the element part, and the tertiary electrode is arranged around the center of the element part from each primary electrode. Are arranged at a position (360 ° × 2 / 4n) away from each other, and the fourth electrode is located at a position (360 ° × 3 / 4n) away from each primary electrode in a direction around the center of the element portion. Arranged and said element And an angular force sensor that generates a primary vibration in a cosnθ mode in a plane in the element portion by an electrostatic force or electromagnetic force generated between the first electrode and any one of the first to fourth electrodes. A first AC power source that generates an in-plane cosnθ mode primary vibration in the element portion by applying an AC voltage and a change in the magnitude of an electric signal generated in a connected electrode are detected, and the first AC current is detected. A first detecting means for controlling the magnitude of the voltage; a second detecting means for detecting a change in the magnitude of the electric signal generated at the connected electrode; and the magnitude of the electric signal detected by the second detecting means. A second AC power supply that applies a second AC voltage that cancels the change to the connected electrodes, the first AC power supply for the first to fourth electrodes, the first detection means, the second detection means, and the second 2 AC Switching means for switching the connection state of the source between the following first state and the following second state; and arithmetic means for calculating an angular velocity in the first state and the second state based on the second AC voltage. An angular velocity sensor is provided.
The first state is:
In one direction around the center of the element portion, an electrode connected to the first AC power supply, an electrode connected to the second AC power supply, an electrode connected to the first detection means, and the second detection means The connected electrodes are in this order.
The second state is:
In another direction around the center of the element portion, an electrode connected to the first AC power supply, an electrode connected to the second AC power supply, an electrode connected to the first detection means, and the second detection means The connected electrodes are in this order.

  The angular velocity sensor according to the third means includes a first AC power supply (corresponding to an AC power supply of the angular velocity sensor according to the first means and the second means), a first detection means, and a second detection means (first means). And a second AC power source). In the angular velocity sensor according to the third means, the second AC voltage that cancels the change in the magnitude of the electric signal detected by the second detection means is applied by the second AC power source. That is, the angular velocity sensor according to the third means cancels the generated secondary vibration by applying the second AC voltage corresponding to the magnitude of the secondary vibration. The second AC power source is arranged at a position (360 ° × 1 / 4n) away from the electrode to which the first AC power source is connected in the direction around the center of the element portion in both the first state and the second state. Connected to the connected electrode. As described above, the secondary vibration is an in-plane cosnθ mode vibration in which the maximum expansion and contraction direction is different from the primary vibration (360 ° × 1 / 4n). The distance of fluctuates according to the secondary vibration. Therefore, the generated secondary vibration can be canceled by applying the second AC voltage to the electrode to which the second AC power source is connected. Thus, by canceling the generated secondary vibration, the magnitude of the generated secondary vibration is made difficult to deviate from the magnitude corresponding to the angular velocity of the rotational motion around the normal direction of the element portion. Further, the first detection means of the angular velocity sensor according to the third means is configured to move in the direction around the center of the element portion from the electrode to which the first AC power source is connected (360) in both the first state and the second state. ° × 2 / 4n) is connected to an electrode arranged at a distance. As described above, since the primary vibration is in-plane cosnθ mode vibration, an electrical signal having a magnitude corresponding to the primary vibration is generated at the electrode connected to the first detection means. The first detection means controls the magnitude of the first AC voltage based on a change in the magnitude of the electrical signal generated at the connected electrode. Therefore, the angular velocity sensor according to the third means can feedback-control the primary vibration so that the vibration state of the primary vibration is kept constant. As described above, the angular velocity sensor according to the third means can cancel the change in the magnitude of the electric signal detected by the second detection means and can feedback-control the primary vibration, so that the angular velocity detection accuracy is high. Is expensive.

  Further, the angular velocity sensor according to the third means changes the connection state of the first AC power source, the first detection unit, the second detection unit, and the second AC power source with respect to the first to fourth electrodes from the first state to the second state or By switching from the second state to the first state, the positional relationship between the first AC power supply, the first detection means, the second detection means and the electrodes connected to the second AC power supply is changed between the element part and the primary to quaternary electrodes. It is possible to have the same relationship as when the posture is physically reversed. Therefore, the angular velocity sensor according to the third means can detect the angular velocity in the reversed posture without using the reversing mechanism, similarly to the angular velocity sensor according to the first means, so that the configuration is simple. , Weight and manufacturing cost are small and maintainability is good.

As a fourth means, the present invention provides a planar element portion, a primary electrode disposed on the element portion along the direction around the center of the element portion, or opposed to the element portion; A primary electrode, a tertiary electrode and a quaternary electrode, wherein the primary electrode is 1 to (n-1) of n positions located at 360 ° / n intervals in a direction around the center of the element portion. The secondary electrode is arranged at a position (360 ° × 1 / 4n) away from each primary electrode in a direction around the center of the element portion, and the tertiary electrode is arranged at each primary electrode. From the primary electrode to the direction around the center of the element portion (360 ° × 3/4). / 4n) Placed at a distance An angular velocity sensor for generating a primary vibration in a cosnθ mode in a plane in the element portion by an electrostatic force or electromagnetic force generated between the element portion and any one of the first to fourth electrodes. A first AC power source for applying a first AC voltage to the connected electrode and generating an in-plane cosnθ mode vibration at the element portion at a natural frequency of the in-plane cosnθ mode; and an electric signal generated at the connected electrode First detection means for detecting a change in magnitude and controlling the magnitude of the first AC voltage; second detection means for detecting a change in magnitude of an electrical signal generated in a connected electrode; and A second AC power source that applies a second AC voltage that cancels a change in the magnitude of the electrical signal detected by the second detection means to a connected electrode; and the first AC power source for the first to fourth electrodes, Based on the second AC voltage, the switching means for switching the connection state of the first detection means, the second detection means, and the second AC power source between the following first state and the following second state, There is provided an angular velocity sensor comprising a calculation means for calculating the angular velocity in the state and the second state.
The first state is:
In one direction around the center of the element portion, an electrode connected to the first AC power supply, an electrode connected to the second AC power supply, an electrode connected to the first detection means, and the second detection means The connected electrodes are in this order.
The second state is:
In another direction around the center of the element portion, an electrode connected to the first AC power supply, an electrode connected to the second AC power supply, an electrode connected to the first detection means, and the second detection means The connected electrodes are in this order.

  Similarly to the angular velocity sensor according to the second means, the angular velocity sensor according to the fourth means has fewer than n positions where the primary to quaternary electrodes are arranged. Similar to the angular velocity sensor according to the second means, the angular velocity sensor according to the fourth means applies the first alternating voltage to the electrode to which the first alternating current power source is connected, and at the natural frequency of the in-plane cosnθ mode. By vibrating the element portion, primary vibration in the in-plane cosnθ mode is generated in the element portion. The angular velocity sensor according to the fourth means applies the second AC voltage to the electrode to which the second AC power source is connected, and vibrates the element portion at the natural frequency of the in-plane cosnθ mode. Cancels the secondary vibration generated in Thus, since the angular velocity sensor according to the fourth means can generate the primary vibration and cancel the secondary vibration, the angular velocity can be detected similarly to the angular velocity sensor according to the third means. it can. Further, the angular velocity sensor according to the fourth means is connected to the first AC power source or the like by switching the connection state of the first AC power source or the like to the primary to quaternary electrodes, similarly to the angular velocity sensor according to the third means. The positional relationship of the formed electrodes can be made the same as the case where the postures of the element part and the primary to quaternary electrodes are physically reversed. Therefore, the angular velocity sensor according to the fourth means can detect the angular velocity in the reversed posture without using the reversing mechanism similarly to the angular velocity sensor according to the third means, so that the configuration is simple. , Weight and manufacturing cost are small and maintainability is good.

  The element part of the angular velocity sensor according to the first to fourth means can be formed in a ring shape, for example.

  As a fifth means, the present invention provides a planar element portion, a primary electrode disposed on the element portion along a direction around the center of the element portion, or a second electrode disposed opposite to the element portion. A primary electrode, and the primary electrode is disposed at at least one of two positions 180 degrees away from each other in the direction around the center of the element portion, and the secondary electrode extends from the primary electrode to the element portion. Is arranged at a position 90 ° apart in the direction around the center of the element, and the primary vibration of the cosnθ mode in a plane is generated by the electrostatic force or electromagnetic force generated between the element part and the primary electrode or the secondary electrode. An angular velocity sensor that is connected to any one of the primary electrode and the secondary electrode, and applies an AC voltage to the connected electrode, and the element portion An AC power source that primarily vibrates the element part in the direction of a line segment that connects the connected electrode and the center of the element part, and any one of the primary electrode and the secondary electrode in the included plane. Detection means for detecting the magnitude of an electrical signal generated at the connected electrode and the connected electrode, and a connection state of the AC power supply and the detection means with respect to the primary electrode and the secondary electrode. A first state in which the detection means is connected to the secondary electrode and a second state in which the AC power source is connected to the secondary electrode and the detection means is connected to the primary electrode. A switching means for switching, and a calculation means for calculating an angular velocity in the first state and the second state based on a change in the magnitude of an electric signal detected by the detection means, To provide a speed sensor.

  In the angular velocity sensor according to the fifth means, when the element portion performs a rotational motion around the normal direction of the element portion when the element portion is in primary vibration, a magnitude corresponding to the angular velocity of the rotational motion. Secondary vibration occurs in the element portion. The vibration direction of the secondary vibration is in a plane including the element portion, and the vibration direction is a vibration in a direction orthogonal to the primary vibration. The detection means is connected to an electrode disposed at a position 90 ° away from the electrode to which the AC power supply is connected in the direction around the center of the element portion in both the first state and the second state. Therefore, in both the first state and the second state, an electrical signal having a magnitude corresponding to the secondary vibration is generated at the electrode to which the detection means is connected. The angular velocity sensor according to the fifth means detects the angular velocity based on the magnitude of the electrical signal detected by the detecting means. Therefore, the angular velocity sensor according to the fifth means can detect the angular velocity in the first state and the second state. Further, the angular velocity sensor according to the fifth means switches the connection state of the AC power supply and the detection means with respect to the primary to secondary electrodes, thereby changing the positional relationship of the electrodes connected to the AC power supply and the detection means to the element portion and It is possible to have the same relationship as when the primary and secondary electrodes are physically reversed. Therefore, the angular velocity sensor according to the fifth means, like the angular velocity sensor according to the first means, can detect the angular velocity in the reversed posture without using the reversing mechanism, and thus has a simple configuration. , Weight and manufacturing cost are small and maintainability is good.

  Moreover, as one preferable configuration of the angular velocity sensor according to the first to fifth means, the calculation means calculates the angular velocity calculated in the first state and the second state based on the angular velocity in the first state and the second state. The structure which calculates the bias component contained in can be mentioned.

As a specific configuration for calculating a bias component, the said angular velocity calculating means is calculated in the first state y1, the angular velocity which the calculating means is calculated in the second state y2, when the bias component was b ₀ The calculation means can be configured to calculate the bias component b ₀ using the following equation (1).
b ₀ = (y1 + y2) / 2 (1)

  Further, as a preferred configuration, the calculation means may be configured to calculate an angular velocity correction value by correcting the calculated angular velocity using the bias component.

  According to such a preferable configuration, the angular velocity correction value is calculated based on the angular velocity from which the bias component has been removed. Therefore, the angular velocity correction value having a value close to the true angular velocity (the angular velocity of the rotational motion itself to be detected). Is calculated.

As another preferred configuration of the angular velocity sensor according to the first to fifth means, the angular velocity calculated by the calculating means in the first state is y1, and the angular velocity calculated by the calculating means in the second state is y2. When the angular velocity correction value is x, the calculation means can calculate the angular velocity correction value using the following equation (2).
x = (y1-y2) / 2a (2) (a: coefficient)

  According to the above equation (2), the angular velocity correction value that is not affected by the bias component is calculated. Therefore, according to such a preferable configuration, the angular velocity correction value having a value close to the true angular velocity can be calculated.

  Moreover, this invention provides the electronic device provided with the above-mentioned angular velocity sensor.

  The present invention has a simple configuration, a low weight and manufacturing cost, good maintainability, and an angular velocity sensor capable of detecting the angular velocity of the reversed posture, as well as the case where the posture of the gyro element is reversed, and the angular velocity sensor It is an object to provide an electronic device including

(Embodiment 1)
FIG. 1 is a schematic configuration diagram of an angular velocity sensor 1 according to the present embodiment. FIG. 1A is a plan view of a gyro element 2 included in the angular velocity sensor 1 and a functional block diagram of the angular velocity sensor 1. 1 (b) shows an AA end view of FIG. 1 (a). As shown in FIG. 1, the angular velocity sensor 1 includes a gyro element 2, a first AC power supply 11, a first detection means 12, a second detection means 13, a second AC power supply 14, a switching means 15, and a calculation means 16.

  The gyro element 2 includes an element part and primary to quaternary electrodes. As a specific configuration of the gyro element 2, for example, as shown in FIGS. 1A and 1B, an element portion 3, primary to quaternary electrodes 4a to 4d, a support portion 5 and a frame body 6 are provided. A configuration can be mentioned. The gyro element 2 having such a configuration can be formed, for example, by bonding an insulating substrate 2a such as a glass substrate and a semiconductor substrate 2b. As shown in FIG. 1A, an element portion 3, primary to quaternary electrodes 4a to 4d, a support portion 5 and a frame body 6 can be formed on a semiconductor substrate 2b. The element part 3, the primary to quaternary electrodes 4a to 4d, the support part 5 and the frame body 6 can be formed by processing the semiconductor substrate 2b using a MEMS technology (Micro Electro Mechanical System).

  As shown in FIG. 1A, the element portion 3 is formed in a ring shape at the center of the semiconductor substrate 2b. From the element portion 3, a support portion 5 extends in the radially outward direction. The support portion 5 connects the element portion 3 and the frame body 6 and supports the element portion 3 to the frame body 6. The frame body 6 is formed outside the element portion 3, and is placed on the insulating substrate 2a as shown in FIG. On the other hand, the primary to quaternary electrodes 4 a to 4 d are arranged along the direction around the center of the element portion 3 so as to face the element portion 3 in the radial direction of the element portion 3. The primary electrodes 4a can be arranged at intervals of 360 ° / n in the direction around the center of the element portion 3. In addition, the secondary electrode 4b extends from each primary electrode 4a to the direction around the center of the element part 3 (360 ° × 1 / 4n), and the tertiary electrode 4c extends from each primary electrode 4a to the direction around the center of the element part 3 The quaternary electrode 4d can be arranged at a position (360 ° × 3 / 4n) away from each primary electrode 4a in the direction around the center of the element part 3 (360 ° × 2 / 4n). The value of n is not limited as long as it is a positive integer, and is 2 in this embodiment. Therefore, in the present embodiment, the primary electrodes 4 a are arranged at intervals of 180 ° in the direction around the center of the element portion 3, and the secondary electrodes 4 b are 45 in the direction around the center of the element portion 3 from each primary electrode 4 a. The tertiary electrode 4c is 90 ° in the direction around the center of the element part 3 from each primary electrode 4a, and the quaternary electrode 4d is at a position 135 ° away from each primary electrode 4a in the direction around the center of the element part 3. Has been placed. As shown in FIG. 1B, the primary to quaternary electrodes 4a to 4d are placed on the insulating substrate 2a. In addition, as shown to Fig.1 (a), in this embodiment, although the 1st-4th electrodes 4a-4d are formed in the outer side of the element part 3, the 1st-4th electrodes 4a-4d are element parts. 3 may be formed inside.

  The first AC power supply 11, the first detection means 12, the second detection means 13, and the second AC power supply 14 are connected to any one of the primary to quaternary electrodes 4a to 4d, respectively.

  The switching means 15 changes the connection state of the first AC power supply 11, the first detection means 12, the second detection means 13, and the second AC power supply 14 with respect to the primary to quaternary electrodes 4a to 4d. Switch to state. FIG. 2A illustrates the first state, and FIG. 2B illustrates the second state. When viewing FIG. 2A from the front side, an electrode (primary electrode 4a) to which the first AC power source 11 is connected and an electrode to which the second AC power source 14 are connected are clockwise to the center of the element portion 3. The (secondary electrode 4b), the electrode to which the first detection means 12 is connected (tertiary electrode 4c), and the electrode to which the second detection means 13 is connected (quaternary electrode 4d) are positioned in this order. On the other hand, when FIG. 2B is viewed from the front side, an electrode (secondary electrode 4b) to which the first AC power source 11 is connected and a second AC power source 14 are connected to the left of the center of the element portion 3. The electrode (primary electrode 4a), the electrode connected to the first detection means 12 (quaternary electrode 4d), and the electrode connected to the second detection means 13 (tertiary electrode 4c) are positioned in this order.

  2A when viewed from the front side in the first state and when viewed from the back side in FIG. 2B in the second state, it is clockwise with respect to the center of the element portion 3. The electrode to which the first AC power supply 11 is connected, the electrode to which the second AC power supply 14 is connected, the electrode to which the first detection means 12 is connected, and the electrode to which the second detection means 13 are connected are positioned in this order. . Therefore, the positional relationship of the electrodes to which the first AC power supply 11, the second AC power supply 14, the first detection means 12, and the second detection means 13 are connected in the second state is the same as that of the element portion 3 and the first to third states. This is the same as the case where the postures of the fourth electrodes 4a to 4d are physically reversed. For this reason, the angular velocity sensor 1 can be made into the state which reversed the attitude | position of the element part 3 and the 1st-4th electrodes 4a-4d physically by switching a connection state. The inversion is a state in which the orientation of the element part 3 and the primary to quaternary electrodes 4a to 4d is changed by 180 ° so that the normal direction of the element part 3 is changed by 180 °.

  In this embodiment, the connection state is switched between the first to fourth electrodes 4a to 4d, the first AC power source 11, the first detection unit 12, the second detection unit 13, and the second AC power source 14. This is realized by connecting via the switch element S.

  Specifically, as shown in FIG. 1A, the primary electrode 4a and the secondary electrode 4b are connected to the first AC power supply 11 and the second AC power supply 14 through the switch element S, and the tertiary electrode 4c and the quaternary electrode 4d are connected to the first detection means 12 and the second detection means 13 via the switch element S. As shown in FIG. 1A, in the present embodiment, the primary to quaternary electrodes 4a to 4d are arranged at two positions, respectively, but in FIG. The connection state of the primary to quaternary electrodes 4a to 4d arranged at the position and the first AC power source 11, the first detection unit 12, the second detection unit 13 and the second AC power source 14 is shown. Omitted.

  Switching to the first state is performed by switching the switch element S to the state indicated by the solid line in FIG. 1A, and switching to the second state is performed by switching the switch element S to the state indicated by the broken line in FIG. It can be carried out.

  The switching unit 15 notifies the calculation unit 16 whether the current connection state is the first state or the second state. The connection state may be switched automatically according to a program or the like, or may be performed according to an instruction from the user of the angular velocity sensor 1.

  The calculating means 16 calculates the angular velocity based on the second AC voltage applied by the second AC power supply 14. The angular velocity calculated by the calculating means 16 is an angular velocity generated by a rotational movement around the normal direction of the element unit 3 (that is, a direction perpendicular to the paper surface of FIG. 1A). Next, the calculation of the angular velocity performed by the calculation means 16 will be described.

  The first AC power source 11 applies a first AC voltage to an electrode to which the first AC power source 11 is connected (hereinafter referred to as a reference electrode), and causes an electrostatic force to act between the reference electrode and the element portion 3, thereby causing an in-plane A primary vibration of the cos 2θ mode is generated in the element unit 3. As shown in FIGS. 2A and 2B, the first AC power supply 11 is positioned 180 degrees away from each other in the direction around the center of the element portion 3 in both the first state and the second state. It is configured to be able to apply an electrostatic force to the element portion 3 from a direction different by 180 °. For this reason, in this embodiment, the first AC voltage is applied to the reference electrode to which the first AC power supply 11 is connected, so that the center of the element portion 3 and the reference electrode are applied as shown in FIG. A primary vibration in the in-plane cos 2θ mode in which the direction of the straight line connecting to the primary electrode 4a (in FIG. 3A) and the direction orthogonal to the direction of the straight line is the maximum expansion / contraction direction is generated in the element portion 3.

  In the present embodiment, the primary vibration is feedback-controlled by the first detection means 12 so that the vibration state of the primary vibration is kept constant. As shown in FIGS. 2A and 2B, the first detection means 12 is separated from the reference electrode by 90 ° in the direction around the center of the element portion 3 in both the first state and the second state. Are connected to electrodes arranged at different positions. Therefore, the capacitance between the electrode to which the first detection means 12 is connected and the element portion 3 varies according to the primary vibration, and the electrode to which the first detection means 12 is connected corresponds to the primary vibration. A large electrical signal is generated. The first detection means 12 controls the magnitude of the first AC voltage based on the magnitude of the electric signal generated at the electrode to which the first detection means 12 is connected, so that the vibration state of the primary vibration is kept constant. In addition, the primary vibration is feedback-controlled.

  When the element unit 3 performs a rotational motion around the normal direction of the element unit 3 while the element unit 3 is performing primary vibration, a secondary vibration having a magnitude corresponding to the angular velocity of the rotational motion is generated. Occurs. As shown in FIG. 3B, this secondary vibration has a maximum expansion / contraction direction of (360 ° / 4n) from the primary vibration, that is, in this embodiment, n is 2, and therefore, in a plane different by 45 °. This is a vibration in cos 2θ mode. As shown in FIG. 2A, in the first state, the second detection means 13 is a quaternary arranged at a position 45 degrees counterclockwise with respect to the center of the element portion 3 with respect to the reference electrode. As shown in FIG. 2 (b), the second detection means 13 is connected to the electrode 4d, and in the second state, the second detection means 13 is positioned 45 ° clockwise relative to the center of the element part 3 with respect to the reference electrode. Are connected to the tertiary electrode 4c. Therefore, in any of the first state and the second state, the capacitance between the electrode to which the second detection means 13 is connected and the element portion 3 varies according to the secondary vibration, and the second detection. An electric signal having a magnitude corresponding to the secondary vibration is generated at the electrode to which the means 13 is connected, and the second detecting means 13 detects the magnitude of the electric signal generated at the electrode to which the means 13 is connected.

  A second AC voltage having a magnitude corresponding to a change in the magnitude of the electrical signal detected by the second detection means 13 is applied by the second AC power supply 14 to the electrode to which the second AC power supply 14 is connected. Thus, the generated secondary vibration is canceled by applying the second AC voltage. As shown in FIG. 2A, in the first state, the second AC power source 14 is a secondary battery disposed at a position 45 degrees clockwise relative to the center of the element portion 3 with respect to the reference electrode. As shown in FIG. 2 (b), in the second state, the primary electrode 4a is disposed at a position 45 degrees counterclockwise with respect to the center of the element portion 3 with respect to the reference electrode. It is connected to the. Therefore, in any of the first state and the second state, the distance between the electrode to which the second AC power supply 14 is connected and the element portion 3 varies according to the secondary vibration. When a second AC voltage is applied to the electrode to which the second AC power supply 14 is connected, an electrostatic force acts between the electrode to which the second AC power supply 14 is connected and the element portion 3, and secondary vibration is generated. Will be countered. Thus, by canceling the secondary vibration, the magnitude of the generated secondary vibration is made difficult to deviate from the magnitude corresponding to the angular velocity of the rotational movement around the normal direction of the element portion 3. The magnitude of the second AC voltage as described above is input from the second AC power supply 14 to the calculation means 16.

  The calculation means 16 determines the polarity of the angular velocity to be calculated based on the current connection state notified from the switching means 15, and calculates the angular velocity to be calculated based on the second AC voltage input from the second AC power supply 14. Determine the size. The reason for determining the polarity of the angular velocity in this way is that the polarity is reversed in the first state and the second state even if the element portion 3 performs the same rotational movement. This is because when the connection state is switched, the postures of the element unit 3 and the primary to quaternary electrodes 4a to 4d are physically reversed. The polarity of the angular velocity to be calculated is determined so that the current connection state notified from the switching unit 15 is reversed between the first state and the second state. As a specific method of determining the polarity, in the first state or the second state, the fact that the polarity of the second AC voltage input from the second AC power supply 14 is inverted is stored in the computing means 16. The computing means 16 inverts the polarity of the second AC voltage input from the second AC power supply 14 in the first state or the second state. In addition, the determination of the magnitude of the angular velocity based on the second AC voltage is performed, for example, the correspondence relationship between the second AC voltage and the angular velocity is stored in the computing means 16, and the computing means 16 is associated with the second AC voltage. This can be done by determining the magnitude of the angular velocity based on the relationship.

  As described above, in the first state and the second state, the positional relationship of the electrodes to which the first AC power source 11, the first detection unit 12, the second detection unit 13, and the second AC power source 14 are connected is the element portion. 3 and the primary to quaternary electrodes 4a to 4d are in a relationship when the posture is not reversed and when reversed. Therefore, the angular velocity in the first state corresponds to one of the angular velocity in the non-inverted posture or the inverted posture, and the angular velocity in the second state corresponds to either the angular velocity in the non-inverted posture or the inverted posture. To do. Accordingly, the angular velocity sensor 1 can be used in the same manner as when the posture of the element unit 3 and the primary to quaternary electrodes 4a to 4d is not reversed or reversed, even if there is no reversing mechanism for reversing the posture of the element unit 3 and the primary to quaternary electrodes 4a to 4d. The angular velocity at the time of the reverse posture or the reverse posture can be detected. Therefore, the angular velocity sensor 1 can detect the angular velocities in the non-inverted posture and the inverted posture, and has an advantage that the configuration is simple, the weight and manufacturing cost are small, and the maintainability is good.

  Furthermore, the calculation means 16 calculates the bias component included in the angular velocity calculated in the first state and the second state as described above based on the angular velocity in the first state and the second state calculated as described above. Hereinafter, calculation of the bias component will be described.

If the angular velocity calculated by the calculating means 16 in the first state is y1, the angular velocity y1 is expressed by the following equation (3).
y1 = ax + b1 (3) (b1: bias component included in angular velocity y1)
If the angular velocity calculated by the calculating means 16 in the second state is y2, the angular velocity y2 is expressed by the following equation (4).
y2 = −ax + b2 (4) (b2: bias component included in angular velocity y2)
The bias component b1 in the first state is the same when the element unit 3 and the primary to quaternary electrodes 4a to 4d are in the non-inverted posture and when the posture is physically reversed with respect to the non-inverted posture. And the bias component b2 in the second state are not the same. This is because when the first state is switched to the second state, the positional relationship of the electrodes to which the first AC power supply 11, the first detection means 12, the second detection means 13, and the second AC power supply 14 are connected is reversed. However, the postures of the element part 3 and the primary to quaternary electrodes 4a to 4d are not physically reversed.

The bias component includes an inversion component whose polarity is inverted when the element unit 3 and the primary to quaternary electrodes 4 a to 4 d are physically inverted, such as warping of the element unit 3. Therefore, it can be considered that the bias component is composed of an inversion component and a non-inversion component as shown in the following equation (5).
Bias component = non-inverted component + inverted component (5) (The non-inverted component is a component that is influenced by the positional relationship of the electrodes to which the first AC power supply 11 and the like are connected.)

When switching from the first state to the second state, the element portion 3 and the primary to quaternary electrodes 4a to 4d do not physically invert, so the angular velocity y1 detected in the first state and the second state The inversion components of the bias component included in the angular velocity y2 that is sometimes detected have opposite polarities. Therefore, the angular velocity y1 detected in the first state is expressed by the following equation (6), and the angular velocity y2 detected in the second state is expressed by the following equation (7).
_{y1 = ax t + b1 = ax} t + (b1 + b2) / 2 + (b1-b2) / 2 ... (6)
_{y2 = -ax t + b2 = -ax} t + (b1 + b2) / 2- (b1-b2) / 2 ... (7)
(A in equation (6) and (7): coefficient, x _t in equations (6) and (7): true angular velocity, (b1 + b2) / 2 in equations (6) and (7): non-inverted component, equation (B1-b2) / 2 in (6) and (7): Inversion component)
When the true angular velocity of the gyro element 2 at the time of detecting the angular velocity y1 and the angular velocity y2 is the same, adding (7) to the equation (6) and solving for the non-inverted component (b1 + b2) / 2, the non-inverted component is It is represented by equation (8).
(B1 + b2) / 2 = (y1 + y2) / 2 (8)

Therefore, when the true angular velocities of the gyro element 2 at the time of detecting the angular velocities y1 and y2 are the same, that is, when the gyro element 2 is in a constant velocity motion state or a stopped state, the non-included in both the angular velocities y1 and y2 The inversion component can be calculated from the angular velocities y1 and y2 detected in the first state and the second state. In this method, the non-inverted component that can be calculated in this way is calculated as the bias component b ₀ . That is, the arithmetic unit 16 calculates the same value as the non-inverting ingredient of the formula (1) as the bias component b _0.
b ₀ = (y1 + y2) / 2 (1)
Thus, if the gyro element having a small inversion component is used as the gyro element 2 in order to calculate the same value as the non-inversion component as the bias component b ₀ , the angular velocity sensor 1 can calculate the bias component with high accuracy. it can.

  Expression (8) is an expression derived on the assumption that the true angular velocities of the gyro element 2 at the time of detecting the angular velocities y1 and y2 are the same. Therefore, from the viewpoint of calculating the bias component with high accuracy, the difference between the true angular velocities of the gyro element 2 at the time of detecting the angular velocities y1 and y2 is preferably small, and the difference is most preferably zero.

  In addition, in order to calculate the angular velocity with high accuracy, the angular velocity to be substituted into y1 and y2 in the above equation (1) is detected by a sensor or the like, for example, that the gyro element 2 is in a stopped state and a constant velocity motion state. The angular velocities y1 and y2 that are sometimes detected may be used. Further, the angular velocity to be substituted into y1 in the above equation (1) may be an average value of a plurality of angular velocities detected in the first state. Similarly, the angular velocity to be substituted into y2 in the above equation (1) may be an average value of a plurality of angular velocities detected in the second state.

Further, the calculation means 16 corrects the angular velocity calculated using the bias component b ₀ calculated in this way, calculates an angular velocity correction value x, and outputs the angular velocity correction value to a predetermined device, monitor, or the like. The angular velocity correction value is performed using, for example, the following equation (9).
x = (y ₀ −b ₀ ) / a (9) (y ₀ : calculated angular velocity)
Since the angular velocity correction value is calculated based on the angular velocity from which the bias component b ₀ is removed in this manner, the angular velocity correction value has a value close to the true angular velocity. Therefore, an angular velocity correction value having a value close to the true angular velocity is output to a predetermined device or monitor.

The timing of the detection of the angular velocity y1 and y2 that are used to calculate the bias component b ₀ is not limited. As the timing of detection may be, for example, before the timing of the angular velocity y ₀ that is corrected using a bias component b ₀ it is detected. Calculating the timing of detection of the angular velocity y1 and y2 that are used to calculate the bias component b _0, if the before the timing the angular velocity y ₀ is detected, for example, the arithmetic unit 16, on the basis of the angular velocity y1 and y2 been by providing a function of storing bias component b _0, based on the bias component b ₀ calculated, it is possible to correct the angular velocity y _0.

Moreover, the calculating means 16 may calculate the angular velocity correction value x using the following equation (2). The following expression (2) is an expression derived in the same manner as the expression (4) ′ described in the background art section.
x = (y1-y2) / 2a (2)

  In the present embodiment, the connection state between the first AC power supply 11 and the like and the primary to quaternary electrodes 4a to 4d in the second state is not limited to the state shown in FIG. It may be in the state. In the first state, the first AC power supply 11 is the tertiary electrode 4c, the first detection means 12 is the primary electrode 4a, the second detection means 13 is the fourth electrode 4d, and the second AC power supply 14 is the secondary electrode. 4b is connected. An example of the configuration that can be switched to the second state is a configuration as shown in FIG. In addition, in FIG. 4, the connection state with the 1st alternating current power supply 11 grade | etc., About each one of the 1st-4th electrodes 4a-4d is shown, and the connection state about the other is abbreviate | omitted.

  The second state of the second state is that the first AC power supply 11 is the primary electrode 4a, the first detection means 12 is the tertiary electrode 4c, the second detection means 13 is the secondary electrode 4b, and the second AC In this state, the power source 14 is connected to the fourth electrode 4d. An example of a configuration that can be switched to the second state is a configuration as shown in FIG. In addition, in FIG. 5, the connection state with the 1st alternating current power supply 11 grade | etc., About each one of the 1st-4th electrodes 4a-4d is shown, and the connection state about the other is abbreviate | omitted.

  The angular velocity sensor 1 described above can be mounted on an electronic device such as a gyro compass for azimuth measurement. FIG. 6 is a schematic diagram showing a state in which the angular velocity sensor 1 is mounted on an electronic device. As shown in FIG. 6, three sensor modules 10 a to 10 c each including an angular velocity sensor 1 and a substrate 9 on which the angular velocity sensor 1 is mounted are mounted on the electronic device.

  The sensor module 10a is arranged so that the normal direction of the element portion 3 of the angular velocity sensor 1 is parallel to the X axis, and the sensor module 10b is parallel to the normal direction of the element portion 3 of the angular velocity sensor 1 to the Y axis. The sensor module 10c is arranged so that the normal direction of the element part 3 of the angular velocity sensor 1 is parallel to the Z axis. That is, the sensor module 10a is an angular velocity correction value around the X axis of the electronic device, the sensor module 10b is an angular velocity correction value around the Y axis of the electronic device, and the sensor module 10c is an angular velocity correction value around the Z axis of the electronic device. It is arranged so that the value can be calculated.

  Next, a method in which the processor 11 of the electronic device acquires the respective angular velocity correction values around the X axis, the Y axis, and the Z axis using the three angular velocity sensors 1 provided in the sensor modules 10a to 10c will be described. The processor 11 transmits the first switching command and the second switching command to each of the sensor modules 10a to 10c. The first switching command is a command to switch the connection state of the first AC power source 11 and the like to the first to fourth electrodes 4a to 4d of the angular velocity sensor 1 to the first state. The second switching command is a command for switching the connection state of the first AC power supply 11 and the like to the first to fourth electrodes 4a to 4d of the angular velocity sensor 1 to the second state.

  When the first switching command is transmitted from the processor 11 to each of the sensor modules 10a to 10c, the switching unit 15 provided in the angular velocity sensor 1 of each of the sensor modules 10a to 10c causes the primary to quaternary electrodes 4a to 4d. The connection state of the first AC power supply 11 or the like is switched to the first state. Similarly, the switching means 15 will switch the connection state of the 1st alternating current power supply 11 grade | etc., With respect to the 1st-4th electrodes 4a-4d, if a 2nd switching command is received to a 2nd state. Each switching means 15 is provided in the same angular velocity sensor 1 as that of itself when switching to the first state, switching to the first state, and switching to the second state when switching to the second state. The calculation means 16 is notified.

When notified that the switching to the first state is made, each calculating means 16 calculates the angular velocity and stores the calculated angular velocity as the angular velocity y1 in the above equation (1). Further, when notified that the switching to the second state is made, each calculating means 16 calculates the angular velocity and stores the calculated angular velocity as the angular velocity y2 in the above equation (1). Then, each calculation means 16 calculates and stores the bias component b ₀ based on the above equation (1) and the angular velocities y1 and y2. When the bias component b ₀ is stored, the calculating means 16 calculates the angular velocity as needed, calculates the angular velocity correction value x using the above equation (9), and the AD converter includes the angular velocity correction value x in the electronic device. 12 is output as an analog value.

  The AD converter 12 quantizes each angular velocity correction value x around the X axis, Y axis, and Z axis output from the arithmetic means 16 of each processor module 10a to 10c, and sends the quantized angular velocity correction value x to the processor 11. Output. In this way, the processor 11 can acquire angular velocity correction values around the X axis, the Y axis, and the Z axis. In the above description, the calculation and storage of the angular velocities y1 and y2 are performed by the calculation means 16 different from the processor 11, but the processor 11 has a function of calculating and storing the angular velocities y1 and y2. The processor 11 may calculate and store the angular velocities y1 and y2.

Note that the shape of the element portion 3 is not limited to a ring shape, and may be a positive 8n (n: positive integer) square or the like. The center of the element part 3 can be, for example, a point having the same distance from all points on the element part or the center of gravity of the element part 3.
(Embodiment 2)

  The angular velocity sensor 1 according to the first embodiment generates the primary vibration of the cosnθ mode by applying the first AC voltage and the second AC voltage to the electrodes arranged at n (n = 2) positions, and generates cosnθ. Cancel the secondary vibration of the mode. However, it is possible to generate the primary vibration of the cosnθ mode and cancel the secondary vibration of the cosnθ mode by applying the first AC voltage and the second AC voltage to the electrodes arranged at a position smaller than n. is there. In the present embodiment, an angular velocity sensor that applies a first AC voltage and a second AC voltage to electrodes arranged at positions smaller than n to generate a primary vibration of the cosnθ mode and cancels the secondary vibration of the cosnθ mode. Will be described.

  FIG. 7 shows a plan view of the gyro element 2 provided in the angular velocity sensor 1A according to the present embodiment, and a functional block diagram of the angular velocity sensor 1A. In the angular velocity sensor 1 </ b> A, the primary electrode 4 a is arranged in one direction among the two positions positioned in the direction around the center of the element portion 3 (360 ° / 2), that is, at an interval of 180 °. The secondary electrode 4b is arranged at a position (360 ° / 4 × 2), that is, 45 ° apart from the primary electrode 4a in the direction around the center of the element portion 3, and the tertiary electrode 4c is arranged at the primary electrode 4a. From the primary electrode 4a to the direction around the center of the element part 3 in the direction around the center of the element part 3 (360 ° × 2/4 × 2), ie, 90 ° apart. (360 ° × 3/4 × 2), that is, 135 ° apart.

  In the first state of the connection state of the first AC power source 11 and the like to the primary to quaternary electrodes 4a to 4d in the angular velocity sensor 1A, the first AC power source 11 is connected to the primary electrode 4a, and the first detecting means 12 is the tertiary electrode 4c. , The second detection means 13 is connected to the fourth electrode 4d, and the second AC power source 14 is connected to the secondary electrode 4b. On the other hand, in the second state, the first AC power supply 11 is connected to the fourth electrode 4d, the first detection means 12 is connected to the secondary electrode 4b, the second detection means 13 is connected to the primary electrode 4a, The AC power supply 14 is connected to the tertiary electrode 4c.

  Switching to the first state can be performed by switching the switch element S to the state indicated by the solid line in FIG. 7, and switching to the second state can be performed by setting the switch element S to the state indicated by the broken line in FIG.

  When FIG. 7 is viewed from the front side in the first state, an electrode (primary electrode 4a) to which the first AC power source 11 is connected and a second AC power source 14 are connected clockwise around the center of the element portion 3. The electrode (secondary electrode 4b), the electrode connected to the first detection means 12 (tertiary electrode 4c), and the electrode connected to the fourth detection means 13 (quaternary electrode 4d) are positioned in this order. On the other hand, when FIG. 7 is viewed from the back side in the second state, the electrode (quaternary electrode 4d) to which the first AC power supply 11 is connected and the second AC power supply 14 are clockwise to the center of the element portion 3. The connected electrode (tertiary electrode 4c), the electrode connected to the first detection means 12 (secondary electrode 4b), and the electrode connected to the second detection means 13 (primary electrode 4a) are positioned in this order. Therefore, the first AC power supply 11, the second AC power supply 14, and the first detection means 12 are obtained when the FIG. 7 is viewed from the front side in the first state and when the FIG. And the positional relationship of the electrode to which the 2nd detection means 13 was connected corresponds. Therefore, similarly to the angular velocity sensor 1 according to the first embodiment, the angular velocity sensor 1A switches the connection state to change the positional relationship of the electrodes to which the first AC power supply 11 and the like are connected to the element unit 3 and the first to fourth orders. It can be set as the state when the attitude | position of the electrodes 4a-4d is physically reversed.

  The first AC power supply 11 applies a first AC voltage to one connected electrode, vibrates the element portion 3 at the natural frequency of the in-plane cos 2θ mode, and generates the primary vibration of the in-plane cos 2θ mode as an element. Generated in part 3. As a method of vibrating the element unit 3 at the natural frequency of the in-plane cos 2θ mode, there is a method in which the period of the first AC voltage is the reciprocal of the natural frequency of the in-plane cos 2θ mode. Further, the second AC power supply 14 applies a second AC voltage to one connected electrode to vibrate the element portion 3 at the natural frequency of the in-plane cos 2θ mode, so that the secondary of the in-plane cos 2θ mode is obtained. Cancel the vibration. As a method of vibrating the element part 3 at the natural frequency of the in-plane cos 2θ mode, there is a method in which the period of the second AC voltage is the reciprocal of the natural frequency of the in-plane cos 2θ mode. As described above, by applying the first AC voltage and the second AC voltage to one electrode, primary vibration can be generated and secondary vibration can be canceled. The angular velocity of the rotational motion around the normal direction can be detected.

  As described above, the angular velocity sensor 1A can detect the angular velocity and switch the connection state to change the positional relationship of the electrodes to which the first AC power supply 11 and the like are connected to the element unit 3 and the first to fourth electrodes 4a. It can be in the state when the posture of ˜4d is physically reversed. Therefore, the angular velocity sensor 1A can detect the angular velocities of the non-inverted posture and the reversed posture even without the reversing mechanism. Further, since the angular velocity sensor 1A can detect the angular velocity of the reversed posture without using the reversing mechanism, the configuration is simple, the weight and the manufacturing cost are small, and the maintainability is good. The calculation means 16 of the angular velocity sensor 1A uses the angular velocities in the first state and the second state to calculate the bias component and the angular velocity correction value in the same manner as the calculation means 16 of the angular velocity sensor 1 according to the first embodiment. May be calculated.

  In the first state, the electrode to which the first AC power source 11 is connected, the electrode to which the second AC power source 14 is connected, in any one of the clockwise direction and the counterclockwise direction with respect to the center of the element portion 3, If the electrode connected to the first detection means 12 and the electrode connected to the second detection means 13 are positioned in this order, the first AC power supply 11, the second AC power supply 14, the first detection means 12, The 2 detection means 13 may be connected to any of the primary to quaternary electrodes 4a to 4d. For example, the first AC power supply 11 is connected to the secondary electrode 4b, the second AC power supply 14 is connected to the tertiary electrode 4c, the first detection means 12 is connected to the fourth electrode 4d, and the second detection means 13 is connected to the primary electrode 4a. Also good.

  Further, in the second state, the electrode to which the first AC power supply 11 is connected, the electrode to which the second AC power supply 14 is connected, in either the clockwise direction or the counterclockwise direction with respect to the center of the element portion 3, If the electrode connected to the first detection means 12 and the electrode connected to the second detection means 13 are positioned in this order, the first AC power supply 11, the second AC power supply 14, the first detection means 12, The 2 detection means 13 may be connected to any of the primary to quaternary electrodes 4a to 4d. For example, the first AC power supply 11 is connected to the secondary electrode 4b, the second AC power supply 14 is connected to the primary electrode 4a, the first detection means 12 is connected to the fourth electrode 4d, and the second detection means 13 is connected to the tertiary electrode 4c. May be.

(Embodiment 3)
FIG. 8 shows a plan view of the gyro element 2 included in the angular velocity sensor 1B according to the present embodiment, and a functional block diagram of the angular velocity sensor 1B. As shown in FIG. 8, the angular velocity sensor 1 </ b> B according to the present embodiment is that the third to fourth electrodes, the first detection unit, and the second AC power supply are not provided. And different. That is, the angular velocity sensor 1B according to the present embodiment does not perform feedback control of primary vibration and cancellation of secondary vibration. The arrangement positions of the primary to secondary electrodes 4a to 4b are the same as those in the first embodiment. In the present embodiment and the following fourth and fifth embodiments, the first AC power supply 11 is referred to as the AC power supply 11 and the second detection means 13 is referred to as the detection means 13.

  The AC power supply 11 is connected to any one of the primary to secondary electrodes 4a to 4b, and the detection means 13 is connected to any one of them. Specifically, when the AC power supply 11 and the detection means 13 are connected to the primary to secondary electrodes 4a to 4b in the first state, the AC power supply 11 is connected to the primary electrode 4a and the detection means 13 is connected to the secondary electrode 4b. Is done. In the second state, the AC power supply 11 is connected to the secondary electrode 4b, and the detection means 13 is connected to the primary electrode 4a. Switching between the first state and the second state is performed by the switching means 15. Switching to the first state can be performed by switching the switch element S to the state indicated by the solid line in FIG. 8, and switching to the second state can be performed by setting the switch element S to the state indicated by the broken line in FIG.

  In the first state, when FIG. 8 is viewed from the front side, the detection means is located at a 45 ° clockwise position with respect to the center of the element portion 3 with respect to the electrode (primary electrode 4a) to which the AC power supply 11 is connected. The electrode (secondary electrode 4b) to which 13 is connected is located. Further, in the second state, when FIG. 8 is viewed from the back side, the electrode (secondary electrode 4b) to which the AC power supply 11 is connected is positioned at a 45 ° clockwise position with respect to the center of the element portion 3. The electrode (primary electrode 4a) to which the detecting means 13 is connected is located. Therefore, similarly to the angular velocity sensor 1 according to the first embodiment, the angular velocity sensor 1B switches the connection state so that the positional relationship between the electrodes to which the AC power supply 11 and the like are connected is changed between the element unit 3 and the primary to secondary electrodes 4a. It can be set as the state when the attitude | position of -4b is physically reversed.

  In the angular velocity sensor 1 </ b> B according to the present embodiment, the calculation means 16 is based on the change in the magnitude of the electrical signal detected by the detection means 13 and the current connection state notified from the switching means 15. Is calculated. Whether the detection means 13 is in the first state or the second state, the electrode disposed at a position 45 ° away from the electrode to which the AC power source 11 is connected in the direction around the center of the element portion 3. It is connected to the. Therefore, the magnitude of the electrical signal detected by the detection means 13 is a magnitude corresponding to the secondary vibration regardless of whether it is in the first state or the second state. Therefore, the calculation means 16 can calculate the angular velocity in the first state and the second state, similarly to the calculation means 16 according to the first embodiment.

  As described above, the angular velocity sensor 1B can detect the angular velocity similarly to the angular velocity sensor 1 according to the first embodiment, and the positional relationship between the electrodes to which the AC power supply 11 and the detection unit 13 are connected by switching the connection state. Can be in a state where the postures of the element part 3 and the primary to secondary electrodes 4a to 4b are physically reversed. Therefore, the angular velocity sensor 1B can detect the angular velocity in the non-inverted posture and the reversed posture without the reverse mechanism, and can detect the angular velocity in the reverse posture without using the reverse mechanism. The structure is simple, the weight and manufacturing cost are small, and the maintainability is good. The calculation means 16 of the angular velocity sensor 1B according to the present embodiment uses the angular velocities in the first state and the second state in the same manner as the calculation means 16 of the angular velocity sensor 1 according to the first embodiment, The calculation and the angular velocity correction value may be calculated.

(Embodiment 4)
FIG. 9 shows a plan view of the gyro element 2 included in the angular velocity sensor 1C according to the present embodiment, and a functional block diagram of the angular velocity sensor 1C. As shown in FIG. 9, the angular velocity sensor 1C according to the present embodiment is different from the angular velocity sensor 1B according to the third embodiment in that the primary electrode 4a and the secondary electrode 4b are respectively disposed at one position. . In the present embodiment, the primary electrode 4 a and the secondary electrode 4 b are arranged at positions separated from each other by 45 ° in the direction around the center of the element portion 3.

  Similarly to the angular velocity sensor 1B according to the third embodiment, an AC power supply 11 is connected to one of the primary electrode 4a and the secondary electrode 4b, and the other of the primary electrode 4a and the secondary electrode 4b is connected to the other. The detection means 13 is connected. Specifically, in the first state, the AC power supply 11 is connected to the primary electrode 4a, and the detection means 13 is connected to the secondary electrode 4b. In the second state, the AC power supply 11 is connected to the secondary electrode 4b, and the detection means 13 is connected to the primary electrode 4a. Switching between the first state and the second state is performed by the switching means 15. Switching to the first state can be performed by switching the switch element S to a state indicated by a solid line in FIG. 9, and switching to the second state can be performed by setting the switch element S to a state indicated by a broken line in FIG.

  In the first state, when FIG. 9 is viewed from the front side, the detection means is located at a 45 ° clockwise position with respect to the center of the element portion 3 with respect to the electrode (primary electrode 4a) to which the AC power supply 11 is connected. The electrode (secondary electrode 4b) to which 13 is connected is located. Further, in the second state, when FIG. 9 is viewed from the back side, the electrode (secondary electrode 4b) to which the AC power supply 11 is connected is positioned at a 45 ° clockwise position with respect to the center of the element portion 3. The electrode (primary electrode 4a) to which the detecting means 13 is connected is located. Therefore, the angular velocity sensor 1C switches the connection state so that the positional relationship of the electrodes to which the AC power supply 11 and the like are connected is physically reversed when the posture of the element unit 3 and the primary to secondary electrodes 4a to 4b is reversed. State.

  Further, since the angular velocity sensor 1C has one electrode to which the AC power supply 11 is connected, similarly to the angular velocity sensor 1A according to the second embodiment, one position is provided in the same manner as the angular velocity sensor 1A according to the second embodiment. A first AC voltage is applied to the electrode arranged at, and the element unit 3 is vibrated in the in-plane cos 2θ mode. The calculating means 16 of the angular velocity sensor 1C calculates the angular speed based on the change in the magnitude of the electric signal detected by the detecting means 13 and the current connection state notified from the switching means 15. Similarly to the detection means 13 of the angular velocity sensor 1B according to the third embodiment, the detection means 13 is in the element portion 3 with respect to the electrode to which the AC power supply 11 is connected regardless of whether the detection means 13 is in the first state or the second state. Are connected to electrodes arranged at positions different by 45 ° in the direction around the center of the. Therefore, the calculation means 16 of the angular velocity sensor 1C can calculate the angular velocities in the first state and the second state, similarly to the angular velocity sensor 1B according to the third embodiment.

  As described above, the angular velocity sensor 1C can detect the angular velocities in the first state and the second state, and can switch the connection state to change the positional relationship between the electrodes to which the AC power supply 11 and the detection means 13 are connected. It can be set as the state when the attitude | position of the part 3 and the primary-secondary electrodes 4a-4b are reversed. Therefore, the angular velocity sensor 1C can detect the angular velocity of the non-inverted posture and the reversed posture without the reverse mechanism, and can detect the angular velocity of the reversed posture without using the reverse mechanism. The structure is simple, the weight and manufacturing cost are small, and the maintainability is good.

<Modification of Embodiments 1 to 4>
In the first to fourth embodiments, n in the mathematical expression defining the arrangement positions of the primary to quaternary electrodes 4a to 4d has been described as 2. However, n is not limited to 2, and may be 3 or more.

  For example, in the angular velocity sensor 1 of the first embodiment, the configuration when n is 3 is as follows. FIG. 10 is a diagram showing a connection state of the first AC power supply 11, the first detection means 12, the second detection means 13, and the second AC power supply 14 with respect to the primary to quaternary electrodes 4a to 4d. Shows the first state and FIG. 10B shows the second state. As shown in FIGS. 10A and 10B, the primary electrodes 4 a are arranged at intervals of 120 ° in the direction around the center of the element portion 3, and the secondary electrodes 4 b are arranged from each primary electrode 4 a to the element portion 3. The tertiary electrode 4c is arranged at a position away from each primary electrode 4a by 60 ° in the direction around the center of the element part 3 and the quaternary electrode 4d is arranged at each primary electrode. The electrode 4 a is disposed at a position 90 ° away from the electrode 4 a in the direction around the center of the element portion 3.

  When FIG. 10A is viewed from the front side, an electrode (primary electrode 4a) to which the first AC power source 11 is connected and an electrode (to which the second AC power source 14 is connected) are connected clockwise to the center of the element portion 3. The secondary electrode 4b), the electrode connected to the first detection means 12 (tertiary electrode 4c), and the electrode connected to the second detection means 13 (quaternary electrode 4d) are positioned in this order. 10B, the electrode (secondary electrode 4b) to which the first AC power source 11 is connected and the second AC power source 14 are connected clockwise from the center of the element portion 3. The electrode (primary electrode 4a), the electrode connected to the first detection means 12 (quaternary electrode 4d), and the electrode connected to the second detection means 13 (tertiary electrode 4c) are positioned in this order. Therefore, even if it is the structure corresponding to the case where n is 3, the angular velocity sensor is the electrode to which the 1st alternating current power supply 11 grade | etc., Was connected by switching a connection state similarly to the angular velocity sensor 1 which concerns on Embodiment 1. Can be set to a state when the postures of the element portion 3 and the primary to quaternary electrodes 4a to 4d are physically reversed.

  Further, in such a configuration, the first AC power supply 11 is connected to electrodes arranged at positions 120 degrees apart from each other in the direction around the center of the element portion 3 in both the first state and the second state. ing. For this reason, in such a configuration, the primary vibration is in the in-plane cos 3θ mode. Further, in the first state and the second state, the first detection means 12 is separated from the reference electrode by 60 ° (360 × 2 / (4 × 3)) in the direction around the center of the element portion 3. Are connected to electrodes arranged at different positions. Further, the second detection means 13 and the second AC power supply 14 are connected to an electrode arranged at a position 30 ° (360 × 1 / (4 × 3)) away from the reference electrode in the direction around the center of the element portion 3. Has been. Therefore, even in such a configuration, the angular velocities in the first state and the second state can be detected based on the second AC voltage.

  As described above, in the first state and the second state, the positional relationship of the electrodes to which the first AC power supply 11, the first detection means 12, the second detection means 13, and the second AC power supply 14 are connected is the element portion. 3 and the primary to quaternary electrodes 4a to 4d are in a relationship when the posture is not reversed and when reversed. Therefore, the angular velocity in the first state corresponds to one of the angular velocity in the non-inverted posture or the inverted posture, and the angular velocity in the second state corresponds to either the angular velocity in the non-inverted posture or the inverted posture. To do. Therefore, even in such a configuration, even if there is no reversing mechanism, the angular velocities of the non-reversing posture and the reversing posture can be detected as in the case of physically reversing.

(Embodiment 5)
FIG. 11 is a plan view of the gyro element 2 included in the angular velocity sensor according to the present embodiment. As shown in FIG. 11, the gyro element 2 of the angular velocity sensor according to the present embodiment includes a planar element portion 3, primary to secondary electrodes 4 a to 4 b, a support portion 5, and a frame body 6.

  For example, the element portion 3 can have a square shape in plan view and a disk shape in plan view as shown in FIG. The element portion 3 is supported by the frame body 6 by the support portion 5.

  The primary to secondary electrodes 4 a to 4 b are arranged to face the element portion 3 along the direction around the center of the element portion 3. The primary electrode 4 a is arranged at one of two positions that are 180 ° apart from each other in the direction around the center of the element portion 3. The secondary electrodes 4a to 4b are arranged at positions 90 ° apart from the primary electrode 4a in the direction around the center of the element portion 3.

  Furthermore, although not illustrated in FIG. 11, the angular velocity sensor according to the present embodiment is an AC power source 11 corresponding to the first AC power source 11 of the angular velocity sensor 1 according to the first embodiment, and the angular velocity sensor according to the first embodiment. The detection means 13 corresponding to the 1st 2nd detection means 13, the switching means 15, and the calculating means 16 are provided. The AC power supply 11 is connected to any one of the primary to secondary electrodes 4a to 4b, and the detection means 13 is connected to any one of them. Specifically, when the AC power supply 11 and the detection means 13 are connected to the primary to secondary electrodes 4a to 4b in the first state, the AC power supply 11 is connected to the primary electrode 4a and the detection means 13 is connected to the secondary electrode 4b. Is done. In the second state, the AC power supply 11 is connected to the secondary electrode 4b, and the detection means 13 is connected to the primary electrode 4a. Switching between the first state and the second state can be performed by switching the switch element connecting the primary to secondary electrodes 4 a to 4 b, the AC power supply 11, and the detection unit 13 by the switching unit 15. The switching unit 15 notifies the calculation unit 16 whether the current connection state is the first state or the second state.

  The AC power supply 11 is connected in a plane including the element part 3 by applying a first AC voltage to the connected electrode and causing an electrostatic force to act between the connected electrode and the element part 3. The element portion 3 is subjected to primary vibration in the direction of the line segment connecting the electrode and the center of the element portion 3 (in the first state, the vibration direction is the vibration in the direction of arrow P shown in FIG. 11). The detection means 13 detects the magnitude of an electrical signal generated at the connected electrode.

  The calculation means 16 detects the angular velocity based on the magnitude of the electrical signal detected by the detection means 13 and the current connection state notified from the switching means 15. Next, the calculation of the angular velocity performed by the calculation means 16 will be described.

  When the element unit 3 performs a rotational motion around the normal direction of the element unit 3 (that is, a direction perpendicular to the paper surface of FIG. 11) when the element unit 3 is primarily oscillating, it corresponds to the angular velocity of the rotational motion. A secondary vibration of a magnitude occurs. The vibration direction of the secondary vibration is in a plane including the element portion 3 and is perpendicular to the primary vibration (in the first state, the direction of the arrow Q shown in FIG. 11). For this reason, for example, in the first state, the electricity generated in the secondary electrode 4b disposed at a position 90 ° away from the primary electrode 4a to which the AC power supply 11 is connected in the direction around the center of the element portion 3. The magnitude of the signal varies according to the secondary vibration. The detecting means 13 is connected to an electrode arranged at a position 90 ° away from the electrode to which the first AC power supply 11 is connected in the direction around the center of the element portion 3 in both the first state and the second state. Has been. Therefore, the calculating means 16 can detect the angular velocity based on the magnitude of the electric signal detected by the detecting means 13.

  Moreover, the AC power supply 11 and the detection are performed by switching the connection state between the primary and secondary electrodes 4a to 4b, the AC power supply 11 and the detection means 13 from the first state to the second state or from the second state to the first state. The positional relationship of the electrodes connected to the means 13 can be made the same as that when the posture of the element unit 3 and the primary to secondary electrodes 4a to 4b are physically reversed. Therefore, the angular velocity sensor according to the present embodiment does not physically invert the posture of the element unit 3 and the primary to secondary electrodes 4a to 4b, but the angular velocity of the reversed posture is equivalent to that when physically reversed. Can be detected. As described above, the angular velocity sensor according to the present embodiment can detect the angular velocity in the reversed posture without using the reversing mechanism, so that the configuration is simple, the weight and the manufacturing cost are small, and the maintainability is low. good.

<Angular velocity sensor using electromagnetic force>
In the angular velocity sensors according to the first to fifth embodiments described above, the occurrence of primary vibration and the cancellation of the change in the magnitude of the electrical signal detected by the second detection means 13 (cancellation of the secondary vibration) are as follows: It is done using electrostatic force. However, the generation of the primary vibration and the cancellation of the secondary vibration may be performed using an electromagnetic force instead of the electrostatic force.

  When electromagnetic force is used, a magnetic field in the normal direction of the element unit 3 is generated in the element unit 3. For example, when the magnets are arranged on both sides in the normal direction of the element part 3 or when the element part 3 has a ring shape as shown in FIG. It can be formed by arranging the magnet 7 inside the element portion 3 so that one side of the direction is the S pole and the other side is the N pole.

  Fig.12 (a) is a top view of the element part 3 by which the primary-quaternary electrodes 4a-4d are arrange | positioned. As shown in FIG. 12A, when using electromagnetic force, the primary to quaternary electrodes 4 a to 4 d are arranged on the element portion 3 along the direction around the center of the element portion 3. The primary electrodes 4a can be arranged at intervals of 360 ° / n in the direction around the center of the element part 3, and the secondary electrodes 4b are arranged in the direction around the center of the element part 3 from each primary electrode 4a (360 °). × 1 / 4n), the tertiary electrode 4c is in the direction around the center of the element part 3 from each primary electrode 4a (360 ° × 2 / 4n), and the fourth electrode 4d is the center of the element part 3 from each primary electrode 4a. They can be arranged at positions separated in the surrounding direction (360 ° × 3 / 4n). In addition, in Fig.12 (a), it is a top view when n of the numerical formula which prescribes | regulates the arrangement position of the primary-quaternary electrodes 4a-4d is set to 2. In FIG. Furthermore, as shown in FIG. 12A, the primary to quaternary electrodes 4 a to 4 d are formed in an arc shape having the same length along the direction around the center of the element portion 3.

  The first AC power supply 11, the first detection means 12, the second detection means 13, and the second AC power supply 14 are connected to any one of the primary to quaternary electrodes 4a to 4d. As shown in FIG. 12 (b), the first AC power supply 11 is on the electrode 4 to be connected so that current flows in the longitudinal direction of the electrode 4 to be connected (direction of arrow L in FIG. 12 (b)). It is connected to two points (point A and point B in the example of FIG. 12B). Also in the 1st detection means 12, the 2nd detection means 13, and the 2nd AC power supply 14, it is connected to two points on the electrode to be connected for the same reason.

  Next, using the case where the connection state of the first AC power supply 11 and the like to the primary to quaternary electrodes 4a to 4d is the first state shown in FIG. 2A, primary vibration is generated by electromagnetic force. And it demonstrates that a secondary vibration is canceled. When the first AC voltage is applied to the primary electrode 4a to which the first AC power supply 11 is connected, a current flows in the longitudinal direction of the primary electrode 4a in the primary electrode 4a. When a current flows in the longitudinal direction of the primary electrode 4a, an electromagnetic force in the direction of the arrow R (radial direction) shown in FIG. 12A is applied to the primary electrode 4a by the current and the magnetic field in the normal direction of the element portion 3. appear. Due to this electromagnetic force, the portion where the primary electrode 4a of the element part 3 is disposed vibrates in the direction of the arrow R, and this vibration causes primary vibration in the cos 2θ mode. Further, when a second AC voltage is applied to the secondary electrode 4b to which the second AC power supply 14 is connected, a current flows in the longitudinal direction of the secondary electrode 4b in the secondary electrode 4b. When a current flows in the longitudinal direction of the secondary electrode 4b, the electromagnetic force in the arrow R ′ direction (radial direction) shown in FIG. 12A is secondary due to the current and the magnetic field in the normal direction of the element portion 3. It occurs on the electrode 4b. Due to this electromagnetic force, the portion of the element portion 3 where the secondary electrode 4b is disposed vibrates in the direction of the arrow R ′, and the secondary vibration of the element portion 3 is canceled by this vibration. On the other hand, when the portion where the tertiary electrode 4c of the element portion 3 is vibrated due to the primary vibration, the vibration and the magnetic field in the normal direction of the element portion 3 cause a current in the longitudinal direction of the tertiary electrode 4c in the tertiary electrode 4c. Flows. Therefore, an electrical signal having a magnitude corresponding to the primary vibration is generated at the tertiary electrode 4c to which the first detection means 12 is connected. Therefore, the 1st detection means 12 can perform feedback control of a primary vibration. Further, when the portion where the quaternary electrode 4d of the element portion 3 is vibrated due to the secondary vibration, the vibration and the magnetic field in the normal direction of the element portion 3 cause the quaternary electrode 4d to Current flows in the longitudinal direction. Therefore, an electric signal having a magnitude corresponding to the secondary vibration is generated in the quaternary electrode 4d to which the second detecting means 13 is connected, and the second AC voltage corresponding to the magnitude of the electric signal is as described above. The secondary vibration is canceled by being applied to.

  As described above, generation of primary vibration and cancellation of secondary vibration can be performed using electromagnetic force. The first to fourth electrodes 4a to 4d are connected to the support portion 5 (not shown) so that the first AC power source 11 and the like can be connected to the first to fourth electrodes 4a to 4d on the frame 6 (not shown). It may be extended to the frame body 6 via (not).

  Even in the case where electromagnetic force is used, the number of positions where the electrodes to which the first AC voltage and the second AC voltage are applied may be smaller than n as in the second embodiment. Further, as in the third and fourth embodiments, the angular velocity sensor does not include the third to fourth electrodes 4c to 4d, and does not need to perform feedback control of the primary vibration and cancel the secondary vibration. Further, as in the fifth embodiment, the primary electrode 4a is disposed at at least one of two positions that are 180 degrees apart in the direction around the center of the element portion 3, and the secondary electrode 4b is connected to each primary electrode 4a. The element is arranged at a position 90 ° away from the center of the element part 3, and the vibration direction of the primary vibration is within the plane including the element part 3 and the electrode connected to the AC power supply 11 and the center of the element part 3. The direction of the line segment that connects

  The present invention will be further described using the angular velocity sensors of Example 1 and Comparative Examples 1 and 2.

Example 1
The angular velocity sensor according to the first embodiment has the same configuration as the angular velocity sensor 1 according to the first embodiment. The angular velocity D calculated by the angular velocity sensor according to the first embodiment is an angular velocity obtained by removing the bias component from the angular velocity detected by the calculation unit. This bias component is calculated using the equation (1) shown in the first embodiment. The maximum angular velocity detected by the calculating means of the angular velocity sensor of the first embodiment is 4.5V, the minimum angular velocity is 0.5V, and the output range of the calculating means of the angular velocity sensor of the first embodiment is 4V (= 4 .5V-0.5V).

(Comparative Example 1)
The angular velocity sensor according to the comparative example 1 has the same configuration as the angular velocity sensor 1 according to the first embodiment except that the detected angular velocity D is different. The angular velocity D detected by the angular velocity sensor of Comparative Example 1 is the angular velocity before the bias component is removed, that is, the angular velocity itself detected by the computing unit based on the second AC voltage.

(Comparative Example 2)
The angular velocity sensor according to the comparative example 2 has the same configuration as the angular velocity sensor 1 according to the first embodiment, except that the bias component calculation method is different. The bias component in the angular velocity sensor of Comparative Example 2 is calculated by substituting the angular velocity when the element portion and the primary to quaternary electrodes are in the non-inverted posture into y1 in the expression (1) shown in the first embodiment. The angular velocity when the quaternary electrode is physically inverted is calculated by substituting for y2 in the formula (1) shown in the first embodiment.

The error of the angular velocity D calculated by the angular velocity sensors of Example 1 and Comparative Examples 1 and 2 described above is shown in the graph shown in FIG. 13 using the least square method. The horizontal axis in FIG. 13 is the true angular velocity. On the other hand, the vertical axis is an error value calculated by the following equation (9).
Error value = ((D−ax) / V) × 100 (D: angular velocity calculated by the angular velocity sensor of Example 1, Comparative Examples 1 and 2, a: coefficient, x: true angular velocity, V: output of angular velocity sensor (Range) ... (9)

  As shown in FIG. 13, the angular velocity D of the angular velocity sensors of Example 1 and Comparative Example 2 is substantially zero when the true angular velocity x is zero. That is, the angular velocity sensors of Example 1 and Comparative Example 2 have good origin passing characteristics. Further, the angular velocity D of the angular velocity sensors of Example 1 and Comparative Example 2 is based on 0 of the true angular velocity x, and the magnitude of an error when the true angular velocity is a positive value and a negative value (absolute Value) is almost the same. That is, the angular velocity sensors of Example 1 and Comparative Example 2 have a characteristic that variations in errors caused by the rotation direction are small.

  Thus, it has been found that by correcting the angular velocity with the bias component calculated by the equation (1) shown in the first embodiment, the origin passing property is good and the variation in error caused by the rotation direction is reduced.

  In addition, the angular velocity sensor of Comparative Example 2 has a good origin passing property as in Example 1, and the variation in error caused by the rotation direction is small, but in order to calculate the angular velocity D calculated by the angular velocity sensor of Comparative Example 2. Requires a reversing mechanism. For this reason, the angular velocity sensor of Comparative Example 2 includes a reversing mechanism, and thus has a complicated configuration, a large weight and manufacturing cost, and poor maintainability compared to the angular velocity sensor of Example 1.

FIG. 1 is a schematic configuration diagram of an angular velocity sensor according to the first embodiment. FIG. 1A shows a plan view of a gyro element included in the angular velocity sensor and a functional block diagram of the angular velocity sensor, and FIG. The AA end elevation of Drawing 1 (a) is shown. FIG. 2 is a diagram showing a connection state of the first AC power source, the first detection unit, the second detection unit, and the second AC power source with respect to the first to fourth electrodes, and FIG. 2 (a) shows the first state. (B) shows a 2nd state. 3A shows the primary vibration of the ring part, and FIG. 3B shows the secondary vibration of the ring part. In addition, the connection state of the 1st alternating current power supply etc. with respect to the 1st-quaternary electrode in Fig.3 (a) and (b) is a 1st state. FIG. 4 is a schematic configuration diagram of the angular velocity sensor according to the first embodiment. FIG. 5 is a schematic configuration diagram of the angular velocity sensor according to the first embodiment. FIG. 6 is an explanatory diagram for explaining how the angular velocity sensor is used. FIG. 7 shows a plan view of a gyro element included in the angular velocity sensor according to the second embodiment and a functional block diagram of the angular velocity sensor. FIG. 8 shows a plan view of a gyro element included in the angular velocity sensor according to the third embodiment and a functional block diagram of the angular velocity sensor. FIG. 9 is a plan view of a gyro element included in the angular velocity sensor according to the fourth embodiment, and a functional block diagram of the angular velocity sensor. FIG. 10 is a diagram illustrating a connection state of the first AC power source, the first detection unit, the second detection unit, and the second AC power source with respect to the first to fourth electrodes, and FIG. 10A illustrates the first state. (B) shows a 2nd state. FIG. 11 is a plan view of a gyro element included in the angular velocity sensor according to the fifth embodiment. FIG. 12 is a diagram for explaining an angular velocity sensor that generates primary vibration and cancels secondary vibration using electromagnetic force, and FIG. 12A is a plan view of an element portion on which primary to quaternary electrodes are arranged. FIG. 12B is a diagram showing a connection form of the first AC power source and the electrodes connected to the first AC power source. FIG. 13 shows the experimental results of measuring the error of the angular velocity calculated by the angular velocity sensors of Example 1 and Comparative Examples 1 and 2. FIG. 14 is an explanatory diagram for explaining the relationship between the angular velocity detected by the angular velocity sensor and the true angular velocity when the gyro element is in the non-inverted posture and in the reversed posture.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1A, 1B, 1C Angular velocity sensor 2 Gyro element 3 Element part 4a Primary electrode 4b Secondary electrode 4c Tertiary electrode 4d Fourth electrode

Claims (11)

A planar element part, and a primary electrode and a secondary electrode arranged on the element part along a direction around the center of the element part, or arranged opposite to the element part, and the primary electrode is , Arranged in the direction around the center of the element part at an interval of (360 ° / n (n is an integer of 2 or more)), and the secondary electrode extends from the primary electrode in the direction around the center of the element part. (360 ° × 1/4 n) away from each other, and the primary vibration of the cosnθ mode in the plane is generated by the electrostatic force or electromagnetic force generated between the element portion and the primary electrode or the secondary electrode. An angular velocity sensor to be generated in a part,
An AC power source connected to any one of the primary electrode and the secondary electrode, and applying an AC voltage to the connected electrode to generate in-plane cosnθ mode primary vibration in the element portion;
Detecting means connected to any one of the primary electrode and the secondary electrode and detecting the magnitude of an electric signal generated in the connected electrode;
A connection state of the AC power source and the detection unit with respect to the primary electrode and the secondary electrode, a first state in which the AC power source is connected to the primary electrode, and the detection unit is connected to the secondary electrode; Switching means for switching to a second state in which the AC power source is connected to the secondary electrode and the detection means is connected to the primary electrode;
An angular velocity sensor comprising: an arithmetic means for calculating an angular velocity in the first state and the second state based on a change in the magnitude of an electric signal detected by the detection means. A planar element part, and a primary electrode and a secondary electrode arranged on the element part along a direction around the center of the element part, or arranged opposite to the element part, and the primary electrode is , Arranged at 1 to (n-1) positions among n positions located at 360 ° / n intervals in the direction around the center of the element portion, and the secondary electrode is connected to each primary electrode. It is arranged at a position (360 ° × 1 / 4n) away from the center of the element part and is in a plane by electrostatic force or electromagnetic force generated between the element part and the primary electrode or the secondary electrode. An angular velocity sensor for generating a primary vibration of the cosnθ mode in the element part,
Connected to one of the primary electrode and the secondary electrode, an AC voltage is applied to the connected electrode, and the primary vibration in the in-plane cosnθ mode is applied to the element portion at the natural frequency of the in-plane cosnθ mode. AC power to be generated,
Detecting means connected to any one of the primary electrode and the secondary electrode and detecting the magnitude of an electric signal generated in the connected electrode;
A connection state of the AC power source and the detection unit with respect to the primary electrode and the secondary electrode, a first state in which the AC power source is connected to the primary electrode, and the detection unit is connected to the secondary electrode; Switching means for switching to a second state in which the AC power source is connected to the secondary electrode and the detection means is connected to the primary electrode;
An angular velocity sensor comprising: an arithmetic means for calculating an angular velocity in the first state and the second state based on a change in the magnitude of an electric signal detected by the detection means. A primary element, a secondary electrode, a tertiary electrode, and a quaternary electrode that are arranged on the element part or opposed to the element part along a direction around the center of the element part and the planar element part The primary electrodes are arranged at intervals of (360 ° / n (n is an integer of 2 or more)) in the direction around the center of the element portion, and the secondary electrodes are separated from the primary electrodes. It is arranged at a position (360 ° × 1 / 4n) away from the center of the element part, and the tertiary electrode extends from each primary electrode to the direction around the center of the element part (360 ° × 2 / 4n). ) The quaternary electrode is arranged at a position (360 ° × 3 / 4n) away from each primary electrode in a direction around the center of the element part, and the element part and the first to Any of the quaternary electrodes By an electrostatic force or an electromagnetic force generated between the bracts, a velocity sensor for generating a primary vibration of the plane cosnθ mode to the element portion,
A first AC power source that applies a first AC voltage to the connected electrodes to generate a primary vibration in a cosnθ mode in the plane in the element portion;
First detection means for detecting a change in the magnitude of an electric signal generated in a connected electrode and controlling the magnitude of the first AC voltage;
Second detection means for detecting a change in the magnitude of an electrical signal generated in the connected electrode;
A second AC power source for applying a second AC voltage that cancels a change in the magnitude of the electrical signal detected by the second detection means to the connected electrode;
Switching means for switching a connection state of the first AC power supply, the first detection means, the second detection means, and the second AC power supply to the primary to quaternary electrodes between the following first state and the following second state; ,
An angular velocity sensor comprising: an arithmetic means for calculating an angular velocity in the first state and the second state based on the second AC voltage.
The first state is:
In one direction around the center of the element portion, an electrode connected to the first AC power supply, an electrode connected to the second AC power supply, an electrode connected to the first detection means, and the second detection means The connected electrodes are in this order.
The second state is:
In another direction around the center of the element portion, an electrode connected to the first AC power supply, an electrode connected to the second AC power supply, an electrode connected to the first detection means, and the second detection means The connected electrodes are in this order. A planar element portion, and a primary electrode, a secondary electrode, a tertiary electrode, and a quaternary electrode that are disposed on the element portion along the direction around the center of the element portion, or are disposed to face the element portion; The primary electrode is disposed at 1 to (n-1) positions among n positions located at 360 ° / n intervals in a direction around the center of the element portion, and the secondary electrode Is arranged at a position (360 ° × 1 / 4n) away from each primary electrode in a direction around the center of the element part, and the tertiary electrode is arranged in a direction around the center of the element part from each primary electrode. (360 ° × 2 / 4n) apart, the quaternary electrode is arranged at a position (360 ° × 3 / 4n) away from each primary electrode in a direction around the center of the element part, The element portion and the By an electrostatic force or an electromagnetic force generated in any one between-quaternary electrode, a velocity sensor for generating a primary vibration of the plane cosnθ mode to the element portion,
Applying a first AC voltage to the connected electrodes, and generating an in-plane cosnθ mode vibration at the element portion at a natural frequency of the in-plane cosnθ mode;
First detection means for detecting a change in the magnitude of an electric signal generated in a connected electrode and controlling the magnitude of the first AC voltage;
Second detection means for detecting a change in the magnitude of an electrical signal generated in the connected electrode;
A second AC power source for applying a second AC voltage that cancels a change in the magnitude of the electrical signal detected by the second detection means to the connected electrode;
Switching means for switching a connection state of the first AC power supply, the first detection means, the second detection means, and the second AC power supply to the primary to quaternary electrodes between the following first state and the following second state; ,
An angular velocity sensor comprising: an arithmetic means for calculating an angular velocity in the first state and the second state based on the second AC voltage.
The first state is:
In one direction around the center of the element portion, an electrode connected to the first AC power supply, an electrode connected to the second AC power supply, an electrode connected to the first detection means, and the second detection means The connected electrodes are in this order.
The second state is:
In another direction around the center of the element portion, an electrode connected to the first AC power supply, an electrode connected to the second AC power supply, an electrode connected to the first detection means, and the second detection means The connected electrodes are in this order.   The angular velocity sensor according to claim 1, wherein the element part is formed in a ring shape. A planar element part, and a primary electrode and a secondary electrode arranged on the element part along a direction around the center of the element part, or arranged opposite to the element part;
The primary electrode is disposed in at least one of two positions that are 180 degrees apart in a direction around the center of the element part, and the secondary electrode extends from each primary electrode in a direction around the center of the element part. An angular velocity sensor that is disposed at a position 90 ° apart and generates primary vibrations in the in-plane cosnθ mode in the element portion by electrostatic force or electromagnetic force generated between the element portion and the primary electrode or the secondary electrode. There,
Connected to any one of the primary electrode and the secondary electrode, applies an AC voltage to the connected electrode, and in the plane including the element part, the connected electrode and the center of the element part An AC power source that primarily vibrates the element portion in the direction of the line segment connecting the
Detecting means connected to any one of the primary electrode and the secondary electrode and detecting the magnitude of an electric signal generated in the connected electrode;
A connection state of the AC power source and the detection unit with respect to the primary electrode and the secondary electrode, a first state in which the AC power source is connected to the primary electrode, and the detection unit is connected to the secondary electrode; Switching means for switching to a second state in which the AC power source is connected to the secondary electrode and the detection means is connected to the primary electrode;
An angular velocity sensor comprising: an arithmetic means for calculating an angular velocity in the first state and the second state based on a change in the magnitude of an electric signal detected by the detection means.   The said calculating means calculates the bias component contained in the angular velocity calculated in the 1st state and the 2nd state based on the angular velocity in the said 1st state and the said 2nd state. The angular velocity sensor according to any one of claims. Wherein the angular velocity calculating means is calculated in the first state y1, the said angular velocity calculating means is calculated in the second state y2, when the bias component and a b _0, the calculating means, the following equation (1) The angular velocity sensor according to claim 7, wherein the bias component b ₀ is calculated by using.
b ₀ = (y1 + y2) / 2 (1)   The angular velocity sensor according to claim 7 or 8, wherein the calculation means calculates an angular velocity correction value by correcting the calculated angular velocity using the bias component. When the angular velocity computed by the computing means in the first state is y1, the angular velocity computed by the computing means in the second state is y2, and the angular velocity correction value is x, the computing means is expressed by the following equation (2) The angular velocity sensor according to claim 1, wherein the angular velocity correction value is calculated using a sensor.
x = (y1-y2) / 2a (2) (a: coefficient)   The electronic device provided with the angular velocity sensor of any one of Claims 1-10.

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