Vibratory gyroscope
AssigneeMurata Manufacturing Co., Ltd.
InventorAnssi Blomqvist
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Abstract
A sensing device comprising a micromechanical gyroscope, the gyroscope comprising an improved sensing device with a micromechanical gyroscope, where the resonance frequency of the first mechanical resonator and the resonance frequency of the second mechanical resonator are adjusted to essentially coincide. The device comprises a feed-back loop connected to the second mechanical resonator, the quality factor of the combination of the feed-back loop and the second mechanical resonator being less than 10. More accurate sensing is achieved without essentially adding complexity to the sensor device configuration.
Claims8
A sensing device comprising a 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 an angular velocity, wherein a resonance frequency of the first mechanical resonator and a resonance frequency of the second mechanical resonator are initially set to essentially coincide;
- and
- a damping feed-back loop connected to the second mechanical resonator for damping the sense mode vibration of the second mechanical resonator, the damping feed-back loop comprising a signal processing filter that has a resonant frequency characteristic that coincides with the resonance frequency of the second mechanical resonator, wherein a sign of the signal processing filter is selected such that a phase shift of the damping feed-back loop is either 0 or −π, and an electrical Q value, which is an electrical quality factor, of the signal processing filter is in a range between 3 to 10.
A method of manufacturing a sensing device comprising a micromechanical gyroscope, the gyroscope comprising 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 an angular velocity, the method comprising:
- initially setting a resonance frequency of the first mechanical resonator and a resonance frequency of the second mechanical resonator to essentially coincide;
- and
- connecting a damping feed-back loop to the second mechanical resonator, the damping feed-back loop comprising a signal processing filter that has a resonant frequency characteristic at the resonance frequency of the second mechanical resonator, wherein a sign of the signal processing filter is selected such that a phase shift of the damping feed-back loop is either 0 or −π, and an electrical Q value, which is an electrical quality factor, of the signal processing filter is in a range between 3 to 10.
Dependencies are inferred from the claim text.