Angular Velocity Detecting Apparatus

• US 20110056291A1
• Filed: 07/02/2010
• Published: 03/10/2011
• Est. Priority Date: 09/08/2009
• Status: Abandoned Application

• Current Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.)
• Inventors: Asano, Satoshi, NAKAMURA, Toshiaki, Iwasawa, Hiroshi, Matsumoto, Masahiro
• Application Number:
  US12/830,115
• Publication Number:
  US 20110056291A1
• Time in Patent Office: Days
• US Class Current: 73/504.12
• CPC Class Codes: G01C 19/5719 using planar vibrating masses driven in a translation vibration along an axis

Abstract

An angular-velocity detecting apparatus including a synchronous-detection unit for performing the synchronous detection of a displacement signal from a vibrator, a unit for changing a voltage value so that the output of the synchronous-detection unit always becomes equal to its maximum value, the voltage value being applied to a resonant-frequency adjusting electrode, and a unit for feeding back the output of the voltage-value changing unit to the resonant-frequency adjusting electrode in a detection-axis direction.

Claims

1. An angular-velocity detecting apparatus, comprising:

a vibrator that is displaceable in a first direction and a second direction which are orthogonal to each other, wherein

said angular-velocity detecting apparatus detects amount of a displacement of said vibrator, said displacement occurring when said vibrator is displaced in said second direction by occurrence of an angular velocity in a state where said vibrator is vibrated in said first direction,

said angular-velocity detecting apparatus, further comprising;

means for detecting a displacement, said displacement occurring permanently in said second direction regardless of said occurrence of said angular velocity; and

means for adjusting resonant frequency in said second direction in correspondence with detection output of said displacement-detecting means.

2. The angular-velocity detecting apparatus according to claim 1, wherein

said displacement is a leakage vibration in said second direction,

said displacement occurring permanently in said second direction independently of said occurrence of said angular velocity, said leakage vibration occurring in said state where said vibrator is vibrated in said first direction.

3. The angular-velocity detecting apparatus according to claim 1, wherein

said means for adjusting said resonant frequency in said second direction adjusts a voltage so that said amount of said detected displacement is always maintained at its maximum value, said voltage being applied to said vibrator.

7. The angular-velocity detecting apparatus according to claim 1, wherein

said means for adjusting said resonant frequency in said second direction generates a signal to apply said signal to said vibrator,

said signal has a frequency equal to resonant frequency in said first direction, or a frequency having a constant frequency difference from said resonant frequency in said first direction.

4. An angular-velocity detecting apparatus, comprising:

a vibrator that is displaceable in a first direction and a second direction which are orthogonal to each other, wherein

said angular-velocity detecting apparatus comprises;

a servo function which functions for suppressing a displacement of said vibrator in said second direction, said displacement occurring by occurrence of an angular velocity in a state where said vibrator is vibrated in said first direction;

said angular-velocity detecting apparatus, further comprising;

servo electrodes provided on said vibrator for suppressing said displacement of said vibrator in said second direction;

means for applying a signal to said vibrator, said signal being designed for vibrating said vibrator in said second direction;

means for detecting said displacement of said vibrator occurring in said second direction; and

means for adjusting resonant frequency in said second direction in correspondence with detection output of said displacement-detecting means.

5. The angular-velocity detecting apparatus according to claim 4, wherein

said signal for vibrating said vibrator in said second direction has a frequency equal to said resonant frequency in said first direction, or a frequency having a constant frequency difference from said resonant frequency in said first direction.

6. The angular-velocity detecting apparatus according to claim 4, wherein

said means for adjusting said resonant frequency in said second direction adjusts a voltage so that said amount of said detected displacement is always maintained at its maximum value, said voltage being applied to said vibrator.