Physical quantity detection apparatus, method of controlling physical quantity detection apparatus, abnormality diagnosis system, and abnormality diagnosis method

• US 8,375,790 B2
• Filed: 06/09/2010
• Issued: 02/19/2013
• Est. Priority Date: 06/12/2009
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group), Seiko NPC Corporation (Seiko Group)
• Original Assignee: Epson Toyocom Corporation (Seiko Group), Seiko Epson Corporation (Seiko Group), Seiko NPC Corporation (Seiko Group)
• Inventors: Sato, Kenji, Takada, Yutaka, Naruse, Hideto, Takahashi, Masayuki
• Primary Examiner(s): Kwok, Helen C.
• Application Number:
  US12/797,113
• Publication Number:
  US 20100326189A1
• Time in Patent Office: 986 Days
• Field of Search: 735/041.2, 735/041.6, 735/040.4, 735/041.5, 735/041.4, 73/13.7, 73/13.8, 73/17.7
• US Class Current: 73/504.12
• CPC Class Codes: G01C 19/56 Turn-sensitive devices using vibrating masses, e.g. vibratory angular rate sensors based on Coriolis forces

Abstract

An angular velocity detection apparatus (i.e., physical quantity detection apparatus) includes a gyro sensor element (i.e., physical quantity detection element) that allows an angular velocity detection signal that corresponds to the magnitude of an angular velocity (i.e., physical quantity) and a leakage signal of vibrations based on a drive signal (square-wave voltage signal) to flow through a detection electrode, a driver circuit that generates the drive signal, a synchronous detection circuit that performs a synchronous detection process on a detection target signal that includes the angular velocity detection signal and the leakage signal based on a detection signal that is synchronized with the drive signal, and a phase change circuit that changes a relative timing of at least one of a rising edge and a falling edge of the detection signal with respect to the detection target signal based on a control signal so that at least part of the leakage signal is output by the synchronous detection process.

Claims

1. A physical quantity detection apparatus that detects a given physical quantity, the physical quantity detection apparatus comprising:

a physical quantity detection element that includes a drive electrode and a detection electrode, and vibrates based on a drive signal supplied to the drive electrode so that a physical quantity detection signal that corresponds to thea magnitude of the physical quantity and a leakage signal of vibrations based on the drive signal flow through the detection electrode;

a driver section that generates the drive signal;

a synchronous detection section that performs a synchronous detection process on a detection target signal that includes the physical quantity detection signal and the leakage signal based on a detection signal that is synchronized with the drive signal; and

a timing change section that changes a relative timing of at least one of a rising edge and a falling edge of the detection signal with respect to the detection target signal based on a control signal so that at least part of the leakage signal is output by the synchronous detection process.

2. The physical quantity detection apparatus as defined in claim 1,

the timing change section changing a phase difference between the detection signal and the detection target signal based on the control signal.

3. The physical quantity detection apparatus as defined in claim 1,

the timing change section changing a duty ratio of the detection signal based on the control signal.

4. The physical quantity detection apparatus as defined in claim 1,

a change amount of the relative timing being adjustable by the timing change section.

5. The physical quantity detection apparatus as defined in claim 1, further comprising:

an abnormality determination section that determines presence or absence of an abnormality of the physical quantity detection apparatus based on a signal output from the synchronous detection section.

6. The physical quantity detection apparatus as defined in claim 1,

the physical quantity being an angular velocity.

7. An abnormality diagnosis system for a physical quantity detection apparatus, the abnormality diagnosis system comprising:

the physical quantity detection apparatus as defined in claim 1; and

an abnormality diagnosis apparatus that supplies the control signal to the physical quantity detection apparatus, receives a signal that is generated by the physical quantity detection apparatus based on a signal output from the synchronous detection section, and diagnoses an abnormality of the physical quantity detection apparatus based on the received signal.

10. The physical quantity detection apparatus as defined in claim 1,

the timing change section changing the relative timing based on whether a detection mode is set or an abnormality diagnosis mode is set, so that at least part of the leakage signal is output by the synchronous detection process in the abnormality diagnosis mode.

8. A method of controlling a physical quantity detection apparatus that includes a physical quantity detection element that includes a drive electrode and a detection electrode, and vibrates based on a drive signal supplied to the drive electrode so that a physical quantity detection signal that corresponds to a magnitude of a given physical quantity and a leakage signal of vibrations based on the drive signal flow through the detection electrode, a driver section that generates the drive signal, and a synchronous detection section that performs a synchronous detection process on a detection target signal that includes the physical quantity detection signal and the leakage signal based on a detection signal that is synchronized with the drive signal, the method comprising:

causing the physical quantity detection apparatus to change a relative timing of at least one of a rising edge and a falling edge of the detection signal with respect to the detection target signal and to perform the synchronous detection process so that at least part of the leakage signal is output from the synchronous detection section; and

causing the physical quantity detection apparatus to generate a signal that corresponds to the leakage signal based on a signal output from the synchronous detection section.

11. The method as defined in claim 8,

the causing of the physical quantity detection apparatus to change the relative timing based on whether a detection mode is set or an abnormality diagnosis mode is set, so that at least part of the leakage signal is output in the abnormality diagnosis mode.

9. A method of controlling a physical quantity detection apparatus that includes a physical quantity detection element that includes a drive electrode and a detection electrode, and vibrates based on a drive signal supplied to the drive electrode so that a physical quantity detection signal that corresponds to a magnitude of a given physical quantity and a leakage signal of vibrations based on the drive signal flow through the detection electrode, a driver section that generates the drive signal, and a synchronous detection section that performs a synchronous detection process on a detection target signal that includes the physical quantity detection signal and the leakage signal based on a detection signal that is synchronized with the drive signal, the method comprising:

causing the physical quantity detection apparatus to change a relative timing of at least one of a rising edge and a falling edge of the detection signal with respect to the detection target signal and to perform the synchronous detection process so that at least part of the leakage signal is output from the synchronous detection section; and

causing the physical quantity detection apparatus to determine presence or absence of an abnormality of the physical quantity detection apparatus based on a signal output from the synchronous detection section.

12. The method as defined in claim 9,

the causing of the physical quantity detection apparatus to change the relative timing based on whether a detection mode is set or an abnormality diagnosis mode is set, so that at least part of the leakage signal is output in the abnormality diagnosis mode.