Sumitomo Precision Products Co., Ltd.

Atlantic Inertial Systems, Inc.

Takafumi Moriguchi

Ryuta Araki

Takashi Ikeda

Hiroshi Nishida

Yasuyuki Hirata

Osamu Torayashiki

Mitsuhiko Takemura

Tsuyoshi Fujimura

Nobutaka Teshima

Ryohei Uchino

Naoki Okimoto

Michael Terence Durston

Michael Durston

A vibrating-type gyroscope element includes a fixed part, a resonator having a vibration mode of cos Nθ (N is a natural number of two or more), support parts, and electrodes. The electrodes are arranged in 4N orientations arranged in an outer circumferential direction of the resonator. The electrodes include at least one primary driving electrode and at least one secondary pickoff electrode. A relationship U≥1 or (S1+S2)−2≥|S1−S2| is satisfied, where S1 is the number of cases where a secondary pickoff electrode is clockwise adjacent to a primary driving electrode, S2 is the number of cases where a secondary pickoff electrode is anticlockwise adjacent to a primary driving electrode, and U is the number of the secondary pickoff electrodes being neither clockwise nor anticlockwise adjacent to a primary driving electrode.

Vibrating-type gyroscope element and angular velocity sensor including same

The azimuth/attitude angle measuring device () includes a first angular velocity sensor (), a second angular velocity sensor (), a power supply unit (), and a control unit (). The control unit is configured so that, when an angular velocity, which is to be used in an operation before and after interchanging a function of a primary side control circuit () and a function of a secondary side control circuit (), is detected by one of the first angular velocity sensor and the second angular velocity sensor, the control unit does not perform control for interchanging the function of the primary side control circuit and the function of the secondary side control circuit in the other of the first angular velocity sensor and the second angular velocity sensor.

Azimuth/attitude angle measuring device

A vibrating-type gyroscope element includes a fixed part, a resonator having a cos Nθ (N is a natural number of two or more) mode of vibration, support parts, and electrodes. The electrodes are arranged in 4N orientations arranged in an outer circumferential direction of the resonator. The electrodes include a primary driving electrode, a primary pickoff electrode, a secondary pickoff electrode, and a secondary driving electrode. The primary pickoff electrode is arranged in the same orientation as that of the primary driving electrode, and the secondary driving electrode is arranged in the same orientation as that of the secondary pickoff electrode.

Vibrating-type gyroscope element and angular velocity sensor comprising same

A vibration-type angular velocity sensor () includes a primary side control circuit () and a secondary side control circuit () which are configured so that a function as the primary side control circuit () and a function as the secondary side control circuit () are interchangeable, in which an offset value after interchange and an offset value before interchange are symmetric values with respect to a predetermined reference value.

Vibration-type angular velocity sensor

An azimuth/attitude angle measuring device () includes an angular velocity sensor () and a control unit (). The angular velocity sensor includes a vibrator (), a primary side control circuit (), and a secondary side control circuit (). The control unit is configured to perform control for switching a state of the angular velocity sensor between a first state in which the angular velocity is detected by interchanging a function of the primary side control circuit and a function of the secondary side control circuit and a se cond state in which the angular velocity is detected without the function of the primary side control circuit and the function of the secondary side control circuit being interchanged.

A vibration-type angular velocity sensor () includes a first angular velocity sensor unit () and a second angular velocity sensor unit (). In a predetermined period, the second angular velocity sensor unit performs a process of detecting an angular velocity based on secondary vibration of a vibrator () by a secondary side control circuit () and a process of detecting the angular velocity based on the secondary vibration of the vibrator by the primary side control circuit () by interchanging functions. The first angular velocity sensor unit detects the angular velocity in the predetermined period. The bias component of the first angular velocity sensor unit is calculated based on a first detection result detected by the first angular velocity sensor unit in the predetermined period and a second detection result detected by the second angular velocity sensor unit in the predetermined period.

In a vibrating structure angular rate sensor, a signal generator generates a phase change suppressing signal in which a phase change according to an amplitude of a rectangular wave signal generated by at least one of a first modulator and a second modulator is suppressed.

Vibrating structure angular rate sensor

This vibration-type angular rate sensor corrects a sensor output from a secondary-side control circuit by adding, to a closed control loop of the secondary-side control circuit, an offset value based on the output of a closed control loop of a primary-side control circuit dependent on temperature.

Vibration-type angular rate sensor

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 direction detector that allows true north detection accuracy to be improved is provided. In a direction detector, an attitude changerrotates an angular velocity sensoraround a detection axis and controls an attitude of the angular velocity sensorso that the detection axis is directed in a predetermined measuring direction and an opposite direction to the predetermined measuring direction. A control devicecontrols the attitude changerso that the angular velocity sensorrotates in a first rotation direction around the detection axis before the angular velocity sensorstarts to detect an angular velocity around the predetermined measuring direction. The control devicecontrols the attitude changerso that the angular velocity sensorrotates in a second rotation direction opposite to the first rotation direction around the detection axis and, thereafter, the angular velocity sensorrotates in the first rotation direction around the detection axis before the angular velocity sensorstarts to detect an angular velocity around the opposite direction.

Direction detector

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;.

Growing community of inventors

Amagasaki, Japan

Takafumi Moriguchi