CPC G01C 19/5726 (2013.01) [G01C 19/5762 (2013.01); G01P 3/14 (2013.01)] | 13 Claims |
1. An angular velocity sensor system configured to detect an angular velocity, the angular velocity sensor system comprising:
an angular velocity sensor; and
a controller configured to execute predetermined processing, wherein:
the angular velocity sensor includes
a movable part including
a drive spring,
a detection spring,
a mass part supported via the drive spring and the detection spring, configured to vibrate in a first direction by deformation of the drive spring, and configured to vibrate in a second direction orthogonal to the first direction by deformation of the detection spring due to a Coriolis force when an angular velocity is applied while vibrating in the first direction,
a movable part drive electrode,
a movable part detection electrode, and
a movable part detection excitation electrode, and
a fixed part including
a fixed part drive electrode facing the movable part drive electrode,
a fixed part detection electrode facing the movable part detection electrode, and
a fixed part detection excitation electrode facing the movable part detection excitation electrode,
the angular velocity sensor includes
a drive spring adjustment part configured to change a spring constant of the drive spring, and
a detection spring adjustment part configured to change a spring constant of the detection spring,
the controller is configured to
vibrate the movable part in the second direction by applying a predetermined voltage to the fixed part detection excitation electrode and simultaneously vibrate the movable part in the first direction by applying a predetermined voltage to the fixed part drive electrode,
acquire a first resonance frequency of the movable part, which is in a direction along the first direction, and a second resonance frequency of the movable part, which is in a direction along the second direction,
adjust the spring constant of the drive spring by controlling the drive spring adjustment part, such that the first resonance frequency is maintained at a constant value,
adjust the spring constant of the detection spring by controlling the detection spring adjustment part, such that the second resonance frequency is maintained at a constant value, and
detect the angular velocity on a basis of a result of synchronously detecting a signal from the fixed part detection electrode with the first resonance frequency,
the movable part has, as the second resonance frequency, a detection resonance frequency and a non-detection resonance frequency, which is different from the detection resonance frequency and the first resonance frequency, and
the controller is configured to
acquire, as the second resonance frequency, the non-detection resonance frequency, and
control the detection spring adjustment part to adjust the spring constant of the detection spring, such that the non-detection resonance frequency is maintained at a constant value.
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