Sumitomo Precision Products Co., Ltd.

Atlantic Inertial Systems, Inc.

Sumitomo Precision Products

Ryuta Araki

Takafumi Moriguchi

Takashi Ikeda

Osamu Torayashiki

Hiroshi Nishida

Yasuyuki Hirata

Mitsuhiko Takemura

Tsuyoshi Fujimura

Nobutaka Teshima

Tsuyoshi Takemoto

Kevin Townsend

Christopher Paul Fell

Michael Terence Durston

Ian Michael Sturland

Koji Nakamura

Toru Kitamura

Hiroshi Kawasaki

Michael Durston

A vibratory gyroscope is provided comprising a plurality of secondary pickoff transducers which are each sensitive to the secondary response mode, wherein: at least two of the secondary pickoff transducers comprise skew transducers designed to be sensitive to the primary mode which produce an induced quadrature signal in response thereto. A method of using the gyroscope is provided comprising the steps of arranging electrical connections between the secondary pickoff transducers and a pickoff amplifier so that in use the induced quadrature signal is substantially rejected by the amplifier in the absence of a fault condition, and the amplifier outputs an induced quadrature signal when a fault condition disconnects one of the skew transducers from the amplifier, and a comparator compares the quadrature output from the pickoff amplifier with a predetermined threshold value and provides a fault indication when the predetermined threshold is exceeded.

Fault detection using skewed transducers

A vibratory gyro which is provided with a ring-shaped vibrating body, leg portions flexibly supporting the ring-shaped vibrating body, a plurality of electrodes formed by having a piezoelectric film sandwiched between an upper-layer metallic film and a lower-layer metallic film in the thickness direction, and a fixed potential electrode. The plurality of electrodes include a bank of driving electrodes for exciting primary vibration, detection electrodes for detecting secondary vibration, and suppression electrodes for suppressing the secondary vibration on the basis of a voltage signal from the detection electrodes. The driving electrodes, the detection electrodes and the suppression electrodes are disposed in the region from an outer peripheral edge of the ring-shaped vibrating body to a vicinity of the outer peripheral edge and/or a region from an inner peripheral edge thereof to a vicinity of the inner peripheral edge.

Vibrating gyroscope including piezoelectric film sandwiched between metallic film layers

A vibrating gyroscope according to this invention includes a ring-shaped vibrating bodyhaving a uniform plane, a leg portionflexibly supporting the ring-shaped vibrating body and having a fixed end, a fixed potential electrode, and a plurality of electrodesformed on the plane with a piezoelectric film sandwiched between an upper-layer metallic film and a lower-layer metallic film in a thickness direction thereof. In this case, in a representative example shown in FIG., when one of driving electrodesfor exciting a primary vibration of the ring-shaped vibrating bodyin a vibration mode of cos N&#x3b8; is set as a reference driving electrode, the plurality of remaining electrodesare disposed at specific positions. Such disposition allows this vibrating gyroscope to detect a uniaxial to triaxial angular velocity by adopting a secondary vibration detector inclusive of an out-of-plane vibration mode.

Vibratory gyroscope using piezoelectric film

A vibrating gyroscope comprises a ring-shaped vibrating body () a leg portion () flexibly supporting the body () and having a fixed end, a fixed potential electrode (), and a plurality of electrodes (-) with a piezoelectric film sandwiched between an upper and a lower-layer metallic film in a thickness direction thereof. When N is a natural number of 2 or more, the plurality of electrodes (-) include driving electrodes () for a primary vibration in a vibration mode of cosN&#x3b8;, which are each disposed (360/N)&#xb0; apart from each other in a circumferential direction, first detection electrodes () and second detection electrodes () for detecting a secondary vibration generated when an angular velocity is applied to the body (), which are each disposed in a certain region related to the driving electrode () Each of the electrodes is also disposed in a certain region of the body ().

Vibrating gyroscope using piezoelectric film and method for manufacturing same

A vibrating gyroscope according to this invention includes a ring-shaped vibrating bodyhaving a uniform plane, a leg portionflexibly supporting the ring-shaped vibrating body and having a fixed end, a fixed potential electrode, and a plurality of electrodesformed on the plane with a piezoelectric film sandwiched between an upper-layer metallic film and a lower-layer metallic film in a thickness direction thereof. In this case, in a representative example shown in FIG., when one of driving electrodesfor exciting a primary vibration of the ring-shaped vibrating bodyin a vibration mode of cos N&#x3b8; is set as a reference driving electrode, the plurality of remaining electrodesare disposed at specific positions. Such disposition allows this vibrating gyroscope to excite a primary vibration in an out-of-plane vibration mode of cos 2&#x3b8; as well as detect a uniaxial or biaxial angular velocity by adopting a secondary vibration detector in an in-plane vibration mode of cos 3&#x3b8;.

A MEMS device including a getter film formed inside a hermetic chamber provides stable performance of the MEMS device by electrically stabilizing the getter film. The MEMS device includes a movable portion and a fixed portion formed inside the hermetic chamber. The hermetic chamber is formed by a base material of the MEMS device and glass substrates and having a cavity and cavities made therein. A part of any continuous getter film formed inside the hermetic chamber connects to only one of any one or a plurality of predetermined electrical potentials of the fixed portion and a ground potential of the fixed portion through the base material of the MEMS device.

MEMS device formed inside hermetic chamber having getter film

A vibrator, which is formed in a silicon waferby means of MEMS technique, has eight beam portions (beams)supported at a central portionand extending in the radial direction while mutually keeping the same angle and has a ring portionconnected to the eight beam portions. Outside the ring portion, eight electrodestofor electrostatic actuation, capacitance detection, or the like are spaced uniformly with a gapcreated between the ring portionand the electrodesto. Inside the ring portion, sixteen electrodesfor frequency adjustment are spaced uniformly with a gapcreated between the ring portionand the electrodes

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Takarazuka, Japan

Ryuta Araki