Hitachi, Ltd.

Hitachi-ge Nuclear Energy, Ltd.

Mitsubishi Hitachi Power Systems, Ltd.

Masahiro Tooma

Tetsuya Matsui

Naoyuki Kono

Satoshi Okada

Masahiro Koike

Ryosuke Kobayashi

Yosuke Takatori

Yuji Matsui

Akira Nishimizu

Masatsugu Nishi

Atsushi Baba

Yoshinori Musha

Kouichi Kurosawa

Masahiro Miki

Katsuhiko Hirano

Fujio Yoshikubo

Hayato Mori

Mitsuru Odakura

Kojirou Kodaira

Yutaka Kometani

Toshiyuki Hiraoka

Makoto Senoo

Soushi Narishige

Kimio Yamada

Hirokazu Adachi

Takao Shimura

Manabu Ueno

An object of this invention is to sense a transient displacement of the blade position to thereby detect abnormalities early. The invention includes: one or more first sensors mounted so as to be removable from an outer surface of a casing opposed to blade tips; a second sensor for acquiring a signal from a fixed point on a rotor shaft of the blades; a section configured to extract data groups from an output signal of the first sensor on the basis of information acquired by the second sensor; a section configured to average the data groups; a section configured to determine thresholds from averaged data obtained under a healthy condition; and an assessing section configured to compare magnitude of the thresholds and sensor signals obtained during blade status monitoring. Since a transient displacement of blade position can be sensed, abnormalities can be detected early in this invention. This early detection, in turn, enables a rotation to be stopped during an initial phase of blade damage. The invention is therefore advantageous in minimizing impacts on other devices.

Method and device for monitoring status of turbine blades

A system for attitude control of an underwater vehicleof the present invention includes an underwater vehiclewith a thruster, an assist devicethat is coupled to the underwater vehiclewith a cableand has cable handling equipmentand a thruster, a cable attachment-to-attachment distance detection unitthat detects distance between a cable attachment of the underwater vehicleand a cable dispenser of the assist device, and a control unitthat previously stores the relationship between the attachment-to-attachment distance and cable length including a predetermined amount of slack and determines the amount of cable to be wound up or let out based on the cable length associated with the detected attachment-to-attachment distance.

System for attitude control of underwater vehicle and method for attitude control of underwater vehicle

The position detection system includes a pressure sensor that detects the vertical position of an underwater vehicle, a range sensor unit that detects the relative distances of the underwater vehicle from its surrounding structures; a measurement image acquisition unit that acquires a measurement image of the horizontal plane, an image storage unit that stores images, an image selector that selects one of the stored images that corresponds to the horizontal plane in which the relative distances have been detected, a corresponding-area identification unit that identifies the area in the selected image that corresponds to the measurement image by performing map matching, and a horizontal position calculator that identifies, the pixel that corresponds to the position at which the relative distances have been detected and calculates the horizontal position of the underwater vehicle.

System and method for detecting position of underwater vehicle

A high-pressure water jet is injected from a nozzle scanned and a shock wave generated due to the collapse of bubbles included in the water jet is impacted on a WJP execution object. Tensile residual stress close to the surface of the WJP execution object is improved to compressive residual stress. The shock wave is detected by a pressure sensor and a shock wave generation frequency is obtained. Whether the obtained shock wave generation frequency is larger than a set value or not is decided. When the shock wave generation frequency is larger than the set value, a high-pressure pump is stopped and the injection of the water jet from the nozzle is stopped. When the shock wave generation frequency is equal to or smaller than the set value, the operation condition of the high-pressure pump is changed. The pressure of the water jet injected from the nozzle is increased and the WJP is executed for a part of the WJP execution object where the shock wave generation frequency is equal to or smaller than the set value. Improvement effect of the residual stress of the WJP execution object can be confirmed more accurately.

Water jet peening method and apparatus thereof

In order to make it possible in ultrasonic flaw detection to generate ultrasonic waves containing a main beam only by use of an array probe and clearly identify a defect in a specimen by use of images, an element pitch P (the distance between centers of adjacent ultrasonic transducer elements in the array probe) is set longer than &#xbc; of the wavelength of longitudinal waves generated by the ultrasonic transducer elements and shorter than &#xbd; of the wavelength and reception signals up to time corresponding to the sum of wall thickness round-trip propagation time for longitudinal waves and wall thickness round-trip propagation time for shear waves in the specimen are displayed.

Ultrasonic flaw detecting method and ultrasonic flaw detector

An ultrasonic inspection instrument for detecting a crack and performing sizing in the depth direction of the crack. By a transmitter element array and a receiver element array included in a common sensor, focus points between focused acoustic fields are electronically scanned in a range including a location where half the sum of the transmitting angle of ultrasonic waves to an inspection-target material and the receiving angle of diffraction echoes from the inspection-target material is 30 degrees, so that a tip portion of the crack is detected from the received diffraction echoes. Thus, the detectability of the ultrasonic inspection instrument for detecting diffraction waves in a subject to be inspected and performing crack inspection is stabilized and kept high.

Ultrasonic array sensor, ultrasonic inspection instrument and ultrasonic inspection method

A laser plasma X-ray source has an improved X-ray conversion efficiency and a minimized occurrence of debris, and a semiconductor lithography apparatus using the same and a method therefor are provided. An X-ray generation unit has a vacuum chamber 5 which encases the target; target supply unit 110 which supplies a fine particle mixture gas target into the vacuum chamber 5; a laser irradiation unit 120 which irradiates a laser beam 2 on the particle mixture gas target 10; and a target recovery unit 130 which recovers unused particle mixture gas target from the vacuum chamber 5.

Laser plasma x-ray source, semiconductor lithography apparatus using the

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Tokyo, Japan

Masahiro Tooma