ANGULAR VELOCITY DETECTION CIRCUIT, ANGULAR VELOCITY DETECTION APPARATUS, AND FAILURE DETERMINATION SYSTEM

• US 20100011834A1
• Filed: 07/16/2009
• Published: 01/21/2010
• Est. Priority Date: 07/17/2008
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Epson Toyocom Corporation (Seiko Group)
• Inventors: SATO, Kenji
• Granted Patent: US 8,327,704 B2
• Time in Patent Office: Days
• US Class Current: 73/1.370
• 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 detection circuit is connected to a resonator for making excited vibration on the basis of a drive signal and detects an angular velocity. The angular velocity detection circuit includes: a self-vibration component extraction unit that receives, from the resonator, a detection signal including an angular velocity component based on a Coriolis force and a self-vibration component based on the excited vibration and extracts the self-vibration component from the detection signal; a direct-current conversion unit including an integration unit that integrates an output signal of the self-vibration component extraction unit; and a temperature characteristic compensation unit that compensates for a variation due to a temperature in an output signal of the direct-current conversion unit.

Claims

1. An angular velocity detection circuit that is connected to a resonator for making excited vibration on the basis of a drive signal and detects an angular velocity, the circuit comprising:

a self-vibration component extraction unit that receives, from the resonator, a detection signal including an angular velocity component based on a Coriolis force and a self-vibration component based on the excited vibration and extracts the self-vibration component from the detection signal;

a direct-current conversion unit including an integration unit that integrates an output signal of the self-vibration component extraction unit; and

a temperature characteristic compensation unit that compensates for a variation due to a temperature in an output signal of the direct-current conversion unit.

2. The angular velocity detection circuit according to claim 1, wherein the temperature characteristic compensation unit makes the compensation on the basis of a first-order term of a temperature characteristic of the output signal of the direct-current conversion unit.

3. The angular velocity detection circuit according to claim 2, further comprising

a storage unit storing the first-order term of the temperature characteristic, wherein

the temperature characteristic compensation unit makes the compensation on the basis of the first-order term of the temperature characteristic stored in the storage unit.

4. The angular velocity detection circuit according to claim 1, further comprising

an own failure determination unit that determines whether there is a failure in an angular velocity detection apparatus, on the basis of an output signal of the temperature characteristic compensation unit.

5. The angular velocity detection circuit according to claim 1, wherein

the direct-current conversion unit includes an amplification unit that amplifies a signal, the amplification unit being provided before or after the integration unit.

6. The angular velocity detection circuit according to claim 1, further comprising

an offset addition unit that adds an offset value to a signal, the offset addition unit being provided before or after the temperature characteristic compensation unit.

7. An angular velocity detection apparatus comprising:

a resonator, wherein the resonator makes excited vibration on the basis of a drive signal, obtains a Coriolis force caused by a rotation movement and the excited vibration, and outputs a detection signal including an angular velocity component based on the Coriolis force and a self-vibration component based on the excited vibration; and

an angular velocity detection circuit that is connected to the resonator and detects an angular velocity, the angular velocity detection circuit including;

a self-vibration component extraction unit that receives the detection signal and extracts the self-vibration component from the detection signal;

a direct-current conversion unit including an integration unit that integrates an output signal of the self-vibration component extraction unit; and

a temperature characteristic compensation unit that compensates for a variation due to a temperature in an output signal of the direct -current conversion unit.

8. A failure determination system, comprising:

the angular velocity detection apparatus according to claim 7; and

an external failure determination unit that receives an output signal of the temperature characteristic compensation unit to determine whether there is a failure in the angular velocity detection apparatus.