Multi-axial angular velocity sensor

• US 7,363,814 B2
• Filed: 04/05/2006
• Issued: 04/29/2008
• Est. Priority Date: 03/30/1993
• Status: Expired due to Fees

• Current Assignee: Wacoh Company
• Original Assignee: Kazuhiro Okada
• Inventors: Okada, Kazuhiro
• Primary Examiner(s): Kwok; Helen C.
• Application Number:
  US11/398,380
• Publication Number:
  US 20060179941A1
• Time in Patent Office: 755 Days
• Field of Search: 7350412-50416, 735/040.2, 735/040.3, 735/040.4, 735/143.2, 735/143.4, 738/620.42, 738/620.43
• US Class Current: 73/504.04
• CPC Class Codes: G01C 19/56 Turn-sensitive devices using vibrating masses, e.g. vibratory angular rate sensors based on Coriolis forces
• CPC Class Codes: G01P 15/0907 of the compression mode type
• CPC Class Codes: G01P 15/0922 of the bending or flexing mode type
• CPC Class Codes: G01P 15/11 by inductive pick-up
• CPC Class Codes: G01P 15/123 by piezo-resistive elements, e.g. semiconductor strain gauges
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 15/18 in two or more dimensions
• CPC Class Codes: G01P 2015/084 the mass being suspended at more than one of its sides, e.g. membrane-type suspension, so as to permit multi-axis movement of the mass

Abstract

An angular velocity sensor for detecting angular velocity about a Z-axis in an XYZ coordinate system has a substrate oscillator, a flexible member for connecting the oscillator to a casing, a device for oscillating the oscillator in an X-axis direction, and a detection device detecting deviation of oscillation of the oscillator in a Y-axis direction for indicating the angular velocity about the Z-axis.

Claims

1. An angular velocity sensor for detecting an angular velocity component about a Z-axis in an XYZ three-dimensional coordinate system, said sensor comprising:

an oscillator made of a substrate with an enough thickness to obtain a mass sufficient to provide the sensor with a required sensitivity;

a sensor casing for accommodating the oscillator therewithin;

a flexible member for connecting the oscillator to the sensor casing so that the oscillator can be moved with respect to the sensor casing;

a driving device for oscillating the oscillator in an X-axis direction in said coordinate system; and

a detection device for detecting a deviation of the oscillator in a Y-axis direction in said coordinate system;

wherein a detection value of said detection device is output as a value indicating an angular velocity component about the Z-axis.

2. The angular velocity sensor according to claim 1, wherein the driving device oscillates the oscillator using Coulomb force.

3. The angular velocity sensor according to claim 2, wherein the driving device includes a first electrode provided on the oscillator, a second electrode provided on a fixed member fixed to the sensor casing and an excitation element applying a voltage between said first electrode and said second electrode.

4. The angular velocity sensor according to claim 1, wherein the detection device detects a deviation by measuring a capacitance value.

5. The angular velocity sensor according to claim 4, wherein the detection device includes a capacitance element including a pair of electrodes, a distance between said pair of electrodes being changed based on a deviation of the oscillator caused by Coriolis force.

6. The angular velocity sensor according to claim 1, wherein the driving device oscillates the oscillator using Coulomb force and the detection device detects a deviation by measuring a capacitance value.

7. The angular velocity sensor according to claim 6,

wherein the driving device includes a first electrode provided on the oscillator, a second electrode provided on a fixed member fixed to the sensor casing and an excitation element applying a voltage between said first electrode and said second electrode, and

wherein the detection device includes a capacitance element including a pair of electrodes, a distance between said pair of electrodes being changed based on a deviation of the oscillator caused by Coriolis force.