Vibratory gyroscope
AssigneeMurata Electronics Oy
InventorLasse AALTONEN
Life of this patent
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Abstract
An improved sensing device comprising micromechanical gyroscope and a feed-back loop with a controller for creating a damp control signal. A frequency generator generates a drive signal for drive mode vibration and a reference signal that is in quadrature-phase in relation to the drive mode vibration. The quadrature reference signal is summed with the damp control signal of the controller. The resulting transducer control signal is fed to the second mechanical resonator. Stable cancellation of the actual mechanical quadrature motion is achieved already at the sensing element level, before the detection of the Coriolis signal.
Claims12
A sensing device comprising micromechanical gyroscope, the gyroscope comprising:
- a first mechanical resonator for drive mode vibration;
- a second mechanical resonator coupled to the first mechanical resonator for sense mode vibration corresponding to rotation of the sensing device;
- and the sensing device further comprises
- a feed-back loop comprising a controller for creating a feed-back signal and an electromechanical transducer, the transducer being configured to oppose sense mode vibration of the second mechanical resonator according to an input control signal;
- a frequency generator for generating a drive signal for drive mode vibration and a reference signal that is in quadrature-phase in relation to the drive mode vibration;
- a summing element configured to sum the quadrature reference signal with a output signal of the controller to be fed as feedback signal to the second mechanical resonator.
A method for sensing rotation of a sensing device comprising a micromechanical gyroscope with a first mechanical resonator for drive mode vibration and a second mechanical resonator coupled to the first mechanical resonator for sense mode vibration corresponding to rotation of the sensor device;
- creating a feed-back signal in a feed-back loop comprising a controller and an electromechanical transducer, the transducer being configured to damp sense mode vibration of the second mechanical resonator according to an input signal;
- generating in a frequency generator a drive signal for drive mode vibration and a reference signal that is in quadrature-phase in relation to the drive mode vibration;
- summing the quadrature reference signal with an output signal of the controller to create an input signal for the second mechanical resonator.
Dependencies are inferred from the claim text.