Angular Velocity Sensor Unit And Angular Velocity Sensor Diagnosing Device

• US 20080110259A1
• Filed: 10/06/2005
• Published: 05/15/2008
• Est. Priority Date: 10/07/2004
• Status: Active Grant

• Current Assignee: MOSAID Technologies Inc. (f/k/a Conversant Intellectual Property Management)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Takeno, Shoichi
• Granted Patent: US 7,677,076 B2
• Time in Patent Office: Days
• US Class Current: 73/504.12
• CPC Class Codes: G01C 19/5607 using vibrating tuning forks double-ended tuning forks using planar vibrating masses suspended at opposite ends G01C19/5719

Abstract

An angular velocity sensor unit is provided which can judge failure in both of two angular velocity sensors. It has a first angular velocity sensor (12) and a second angular velocity sensor (13), each including an oscillator having a shaft portion and an oscillatory portion. Each of the angular velocity sensors (12, 13) is arranged such that its shaft portion is not in parallel with an XY-plane defined by an X-axis and a Y-axis of three orthogonal axes. The failure of the second angular velocity sensor is judged based on whether or not a detection value of an angular velocity about a Z-axis lies outside a tolerance range of a detection value of the angular velocity about the Z-axis by the other angular velocity sensor, and the failure of the first angular velocity sensor is judged by comparison with a pseudo-calculated angular velocity.

Claims

1. An angular velocity sensor unit including at least two angular velocity sensors each having an oscillator having a shaft portion and an oscillatory portion, wherein:

the two angular velocity sensors are arranged such that the shaft portions thereof are not in parallel with an XY-plane defined by an X-axis and a Y-axis of three orthogonal axes,

a failure of one of the two angular velocity sensors is judged based on whether or not a detection value of an angular velocity about a Z-axis lies outside a tolerance range of a detection value of an angular velocity about the Z-axis by the other angular velocity sensor, and

the failure of the other angular velocity sensor is judged by comparison with a pseudo-calculated angular velocity.

2. An angular velocity sensor unit according to claim 1, wherein the two angular velocity sensors are arranged such that the shaft portions lie in an XZ-plane defined by the X-axis and Z-axis.

3. An angular velocity sensor unit according to claim 2, wherein the two angular velocity sensors are arranged such that the extensions of the shaft portions are orthogonal to each other.

4. An angular velocity sensor unit according to claim 3, wherein the two angular velocity sensors are arranged such that the shaft portions are symmetrically inclined by 45°

with respect to the Z-axis.

5. An angular velocity sensor unit according to claim 1, wherein the Z-axis is a yaw axis of a movable body, the X-axis is a roll axis of the movable body, and the Y-axis is a pitch axis of the movable body.

6. An angular velocity sensor unit according to claim 5, wherein:

the two angular velocity sensors are respectively arranged in a plane defined by the yaw axis and the roll axis,

one of the two angular velocity sensors is arranged oblique to the roll axis, and

the other of the two angular velocity sensors is arranged in parallel with the yaw axis.

7. An angular velocity sensor unit according to claim 5 to be mounted in a vehicle.

8. An angular velocity sensor diagnosing device, comprising:

an angular velocity sensor unit including at least two angular velocity sensors each having an oscillator having a shaft portion and an oscillatory portion, the two angular velocity sensors being arranged such that the shaft portions thereof are not in parallel with an XY-plane defined by an X-axis and a Y-axis of three orthogonal axes,

a first failure judging circuit for judging a failure of one angular velocity sensor depending on whether or not a detection value of an angular velocity about a Z-axis by the one angular velocity sensor lies outside a tolerance range of a detection value of an angular velocity about the Z-axis by the other angular velocity sensor, and

a second failure judging circuit for judging a failure of the other angular velocity sensor by comparison with a pseudo-calculated angular velocity.