Vibrating-type gyroscope element and angular velocity sensor including same

Patent metadata

Field	Value
Publication number	US-2023358539-A1
Application number	US-202118002961-A
Country	US
Kind code	A1
Filing date	Jun 24, 2021
Priority date	Jul 3, 2020
Publication date	Nov 9, 2023
Grant date	—

Abstract

A vibrating-type gyroscope element includes a fixed part, a resonator having a vibration mode of cos Nθ (N is a natural number of two or more), support parts-30, and electrodes. The electrodes are arranged in 4N orientations arranged in an outer circumferential direction of the resonator. The electrodes include at least one primary driving electrode-PD and at least one secondary pickoff electrode. A relationship U ≥ 1 or (S1 + S2) - 2 ≥ |S1 - S2| is satisfied, where S1 is the number of cases where a secondary pickoff electrode is clockwise adjacent to a primary driving electrode, S2 is the number of cases where a secondary pickoff electrode is anticlockwise adjacent to a primary driving electrode, and U is the number of the secondary pickoff electrodes being neither clockwise nor anticlockwise adjacent to a primary driving electrode.

First claim

1 . A vibrating-type gyroscope element, comprising at least:
a fixed part, a resonator, a plurality of support parts connecting the resonator to the fixed part and vibratably supporting the resonator, a plurality of electrodes formed in a plane of the resonator, and a magnetic field applier that applies a magnetic field to the electrodes in a direction crossing a front surface of the resonator, the resonator having a cos Nθ (N is a natural number of two or more) mode of vibration, the plurality of electrodes being arranged in such 4N orientations that the axes of the electrodes are arranged at equiangular intervals in an outer circumferential direction of the resonator, the plurality of electrodes including at least one primary driving electrode that excites first order vibration of the resonator in the cos Nθ mode and at least one secondary pickoff electrode that detects second order vibration of the resonator, and a relationship of
U ≥ 1 ­­­(1)
or
S1+   S2 -   2 ≥ S1-   S2 ­­­(2)
is satisfied,
where S1 is the number of cases where a primary driving electrode is arranged in an orientation adjacent to a clockwise side of a secondary pickoff electrode, S2 is the number of cases where a primary driving electrode is arranged in an orientation adjacent to a counterclockwise side of a secondary pickoff electrode, and U is the number of secondary pickoff electrodes that a primary driving electrode is not arranged in an orientation adjacent to either the clockwise or counterclockwise side thereof.

2 . The vibrating-type gyroscope element of claim 1 , wherein a relationship of S1 = S2 is satisfied.

3 . The vibrating-type gyroscope element of claim 1 , wherein the electrodes include:
a primary pickoff electrode that detects the first order vibration; and a secondary driving electrode that drives the resonator such that the second order vibration is canceled, the primary pickoff electrode is arranged in an orientation identical to that of the primary driving electrode, and the secondary driving electrode is arranged in an orientation identical to that of the secondary pickoff electrode.

4 . An angular velocity sensor, comprising at least:
the vibrating-type gyroscope element of claim 1 ; a primary AC power supply that applies an AC current with a predetermined frequency to the primary driving electrode; a secondary detector that detects a voltage signal generated at the secondary pickoff electrode, and a computing unit that calculates an angular velocity based on an output signal from the secondary detector.

5 . An angular velocity sensor, comprising at least:
the vibrating-type gyroscope element of claim 3 ; a primary AC power supply that applies an AC current with a predetermined frequency to the primary driving electrode; a primary detector that detects a voltage signal generated at the primary pickoff electrode, a secondary AC power supply that applies an AC current to the secondary driving electrode; a secondary detector that detects a voltage signal generated at the secondary pickoff electrode, and a computing unit that calculates an angular velocity based on an output signal from the secondary AC power supply.

6 . The angular velocity sensor of claim 5 , wherein
an output signal from the primary detector is fed back to the primary AC power supply, so as to stabilize the first order vibration generated at the resonator, based on an output signal from the secondary detector, an output of the secondary AC power supply is controlled such that the second order vibration generated at the resonator is canceled, and the computing unit calculates the angular velocity based on the output signal from the secondary AC power supply.

7 . The vibrating-type gyroscope element of claim 2 , wherein the electrodes include:
a primary pickoff electrode that detects the first order vibration; and a secondary driving electrode that drives the resonator such that the second order vibration is canceled, the primary pickoff electrode is arranged in an orientation identical to that of the primary driving electrode, and the secondary driving electrode is arranged in an orientation identical to that of the secondary pickoff electrode.

8 . An angular velocity sensor, comprising at least:
the vibrating-type gyroscope element of claim 2 ; a primary AC power supply that applies an AC current with a predetermined frequency to the primary driving electrode; a secondary detector that detects a voltage signal generated at the secondary pickoff electrode, and a computing unit that calculates an angular velocity based on an output signal from the secondary detector.

Assignees

• Sumitomo Precision Prod Co

Inventors

• Uchino Ryohei
• Moriguchi Takafumi
• OKIMOTO Naoki

Classifications

• G01C19/5719

  using planar vibrating masses driven in a translation vibration along an axis · CPC title

• B81B2203/04

  Electrodes · CPC title

• B81B2201/0242

  Gyroscopes · CPC title

• B81B3/0086

  Electrical characteristics, e.g. reducing driving voltage, improving resistance to peak voltage · CPC title

• H10N30/302

  Sensors · CPC title