Satoshi Nagai

Bio: Satoshi Nagai is an academic researcher from Toshiba. The author has contributed to research in topics: Ultrasonic sensor & Ultrasonic testing. The author has an hindex of 15, co-authored 113 publications receiving 891 citations.

Welding system and welding method

Abstract: A welding system has: a welding mechanism, a reception laser light source, a reception optical mechanism, an interferometer, a data recording/ analysis mechanism and a data recording/ analysis mechanism. The reception laser light source generates reception laser light so as to irradiate the object to be welded with the reception laser light for the purpose of detecting a reflected ultrasonic wave obtained as a result of reflection of a transmission ultrasonic wave. The reception optical mechanism transmits, during or after welding operation, the reception laser light generated from the reception laser light source to the surface of the object to be welded for irradiation while moving, together with the welding mechanism, relative to the object to be welded and collects laser light scattered reflected at the surface of the object to be welded.

Development of Under-sodium Three-dimensional Visual Inspection Technique Using Matrix-arrayed Ultrasonic Transducer

Abstract: We have developed an advanced under-sodium ultrasonic visual inspection technique in order to observe in-vessel structures in a Fast Breeder Reactor (FBR) whose reactor vessel is filled with opaque liquid sodium. The final goal of this work is achievement of resolution equivalent to that of an image obtained by optical fiber scope. The under-sodium ultrasonic visualizing system consists of a matrix-arrayed transducer and a signal- processing device. The matrix-arrayed transducer, in which 36x36 piezoelectric elements are arranged with 5 mm interval and sealed by a thin metal diaphragm, can realize a 3-dimensional image with high resolution. Regarding signal processing, the 3-dimensional image synthetic processing and the cross correlation processing for the purpose of improving S/N ratio of ultrasonic echoes are implemented on a high-speed parallel processor. Under-sodium imaging test was carried out, and it was confirmed that a 3-dimensional image of the blind target, which was prepared without informati...

Welding inspection method and apparatus thereof

Abstract: A welding inspection method has steps of: generating transmission laser light for generating an ultrasonic wave and transmitting the transmission laser light to an object to be inspected during or after welding operation for irradiation; generating reception laser light for detecting an ultrasonic wave and transmitting the reception laser light to the object to be inspected for irradiation; collecting laser light scattered and reflected at surface of the object to be inspected; performing interference measurement of the laser light and obtaining an ultrasonic signal; and analyzing the ultrasonic signal obtained by the interference measurement. At least one of the transmission laser light generated in the transmission laser light irradiation step and the reception laser light generated in the reception laser light irradiation step is irradiated onto a welded metal part or a groove side surface.

Ultrasonic diagnostic imaging system with universal access to diagnostic information and images

Abstract: A medical ultrasonic diagnostic imaging system is provided which is capable of being accessed over data communication networks such as the Internet, making the ultrasonic images, diagnostic reports, and ultrasound system diagnostics information and operation accessible to a conventional personal computer using commercially available software at virtually any remote location. In one embodiment, the ultrasound system can be remotely operated from the personal computer. The inventive apparatus and techniques make it possible for physicians to remotely access, control, and perform diagnoses using their ultrasound systems over a network such as the World Wide Web with no special hardware requirements.

Hvac system remote monitoring and diagnosis

Abstract: A monitoring system for a heating, ventilation, and air conditioning (HVAC) system of a building includes a monitoring device installed at the building, a monitoring server located remotely from the building, and a review server. The monitoring device measures an aggregate current supplied to components of the HVAC system and transmits current data based on the measured aggregate current. The monitoring server receives the transmitted current data and, based on the received current data, assesses whether failures have occurred in first and second components of the HVAC components. The monitoring server generates a first advisory in response to determining that the failure has occurred in the first component. The review server provides the first advisory to a technician for review and, in response to the technician verifying that the failure has occurred, transmits a first alert.

Residential solutions hvac monitoring and diagnosis

Abstract: A monitoring system for a heating, ventilation, and air conditioning (HVAC) system of a residence includes a monitoring device installed at the residence and a server located remotely from the residence. The monitoring device measures an aggregate current supplied to a plurality of components of the HVAC system and transmits current data based on the measured aggregate current. The server receives the transmitted current data and, based on the received current, assesses whether a failure has occurred in a first component of the plurality of components of the HVAC system and assesses whether a failure has occurred in a second component of the plurality of components of the HVAC system.

Defect detection using ultrasonic arrays: The multi-mode total focusing method

Abstract: Ultrasonic arrays allow a given scatterer to be illuminated from a wide range of angles and hence are capable of extracting significant information about the scatterer. In this paper a general imaging methodology, termed multi-mode total focusing method, is proposed in which any combination of modes and reflections can be used to produce an image of the test structure. Like the total focusing method, this approach is implemented by post-processing the full matrix of array data to achieve a synthetic focus at every pixel in the image. A hybrid model is used to predict the array data and demonstrate the performance of the multi-mode imaging concept. This hybrid model combines far field scattering coefficient matrices with a ray-based wave propagation model. This allows the inclusion of longitudinal waves, shear waves and wave mode conversions. It is shown that, with prior knowledge of likely scatterer location and orientation, the mode combination and array location can be optimised to maximise the performance of array inspections. A practically relevant weld inspection application is then described and its optimisation is discussed.