Patent ID: 7823450
Filing Date: 2010-11-02
Classification: G01C

Abstract:
1. A method of setting temperature characteristics of an angular velocity sensor including a piezoelectric vibrator, a driving circuit arranged to drive the piezoelectric vibrator, the driving circuit and the piezoelectric vibrator defining an oscillation circuit, and a synchronous detection circuit arranged to perform synchronous detection of a voltage signal caused by vibrations of the piezoelectric vibrator arising from the Coriolis force using a detection signal having a predetermined phase angle based on an oscillation period of the oscillation circuit and output an angular velocity detection signal defined by a voltage signal based on the Coriolis force, the method comprising: acquiring temperature characteristics of a detuning frequency that is a frequency difference between an oscillation frequency of the oscillation circuit and a frequency of the voltage signal; acquiring sensitivity characteristics of the detuning frequency; acquiring temperature characteristics of a detection phase that is a phase difference between a Coriolis signal phase that corresponds to a phase angle of the voltage signal and an oscillation signal phase of the oscillation circuit; acquiring sensitivity characteristics of the detection phase; acquiring detuning frequency sensitivity change characteristics that indicate how the sensitivity to the detuning frequency changes in accordance with temperature using the temperature characteristics of the detuning frequency and the sensitivity characteristics of the detuning frequency; acquiring detection phase sensitivity change characteristics that indicate how the sensitivity to the detection phase changes in accordance with the temperature using the temperature characteristics of the detection phase and the sensitivity characteristics of the detection phase; and setting the detection phase so that the detuning frequency sensitivity change is controlled by the detection phase sensitivity change.