• Title/Summary/Keyword: ultrasonic system

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APPLICATION OF DIGITAL ULTRASONIC IMAGE CONSTRUCTION SYSTEM FOR THE DETECTION OF CRACKS IN WATER DISTRIBUTION SYSTEM

  • Lee, Hyun-Dong;Kwak, Phill-Jae;Shin, Hyeon-Jae;Jang, You-Hyun
    • Environmental Engineering Research
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    • v.11 no.2
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    • pp.99-105
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    • 2006
  • A digital ultrasonic image construction system was developed for the nondestructive detection of cracks in water distribution pipes. The system consists of PC based ultrasonic testing system and a scanning device. The PC based ultrasonic system has an ultrasonic pulse/receive board for the generation and reception of ultrasonic signals, an analogue to digital conversion board for the digitization of the received ultrasonic signals, and transducers for the ultrasonic sensors. Using this system, the digitized ultrasonic signals were properly constructed in accordance with the position information obtained by scanning device that moves an ultrasonic transducer along the outer surface of pipes. In the construction of the ultrasonic signals, signal processing concepts, such as spatial average and array concept, were considered to enhance the resolution of ultrasonic images of pipe wall. Using the developed system, crack detection experiments were performed in both laboratory and field, which shows promise for crack detection in the water distribution system.

USAT(Ultrasonic Satellite System) for the Autonomous Mobile Robots Localization (무인 이동 로봇 위치추정을 위한 초음파 위성 시스템)

  • Lee, Dong-Hwal;Kim, Su-Yong;Yoon, Kang-Sup;Lee, Man-Hyung
    • Journal of Institute of Control, Robotics and Systems
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    • v.13 no.10
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    • pp.956-961
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    • 2007
  • We propose a new distance measurement method and local positioning system for the autonomous mobile robots localization. The distance measurement method is able to measure long-range distances with a high accuracy by using ultrasonic sensors. The time of flight of the ultrasonic waves include various noises is calculated accurately by the proposed period detecting method. The proposed local positioning system is composed of four ultrasonic transmitters and one ultrasonic receiver. The ultrasonic transmitter and receiver are separated but they are synchronized by RF (Radio frequency) signal. The proposed system using ultrasonic waves is represented as USAT(Ultrasonic Satellite System). USAT is able to estimate the position using the least square estimation. The experimental results show that the proposed local positioning system enables to estimate the absolute position precisely.

Self-localization of a Mobile Robot Using Global Ultrasonic Sensor System (전역 초음파 센서 시스템을 이용한 이동 로봇의 자기 위치 추정)

  • 이수영;진재호
    • Journal of Institute of Control, Robotics and Systems
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    • v.9 no.2
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    • pp.145-151
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    • 2003
  • A global ultrasonic sensor system for self-localization of a mobile robot is proposed in this paper. The global ultrasonic sensor system consists of three or more ultrasonic transmitters fixed at some positions in the world coordinate and receivers in the moving coordinate of a mobile robot. In this global sensor system it is easy to get state vector of the mobile robot in the world coordinate from the distance information between each ultrasonic transmitter and receiver. An extended kalman filter algorithm is used to process the noisy ultrasonic signal and to estimate the state vector. In case of using several independent ultrasonic transmitters, it is necessary to avoid the cross talk among the ultrasonic waves and to synchronize between each ultrasonic transmitter and receiver. The small sized radio frequency modules are adopted to solve the cross talk and the synchronization problem Computer simulation and experiments are carried out to verify the effectiveness of the proposed ultrasonic sensor system.

Study on the Development of Multi-Path Ultrasonic Gas Flowmeter (전달 시간차 방식 다회선 초음파 가스 유량계 개발)

  • 황원호;박상국;이치환;장경영
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1046-1050
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    • 2003
  • In this paper, we describe study on the development or multi-path ultrasonic gas flowmeter using a transit time method. This system includes 5 pairs of ultrasonic transducers. ultrasonic signal processing unit using switch matrix method, computation algorithm of gas flow rate, spool piece type multi-path pipe unit. We have developed enhanced type of main ultrasonic signal processing unit using switch matrix method fer multi-path ultrasonic gas flowmeter. Also, we have developed the new transmitting & receiving method of ultrasonic waves and the new signal processing algorithm for the computation of ultrasonic transit time from received ultrasonic waves. In this study, we have designed more compact signal processing unit compared with the conventional hardware system of multi-path ultrasonic gas flowmeter. We have confirmed its reliability for multi-path ultrasonic gas flowmeter through the laboratory test using calibration system. In the future. we will perform the field test for the developed system in the POSCO gas line.

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A Study on the Performance of Diesel Automobile Engine with Ultrasonic Fule Supply System(III) (On the case of Turbo-charging Diesel Engine) (초음파 연료공급장치용 디젤자동차의 성능 향상에 관한 연구(III) (과급 디젤기관에 대하여))

  • 최두석;이흥영;류정인
    • Transactions of the Korean Society of Automotive Engineers
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    • v.3 no.4
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    • pp.12-18
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    • 1995
  • To improve the performance of diesel automobile engine, we designed new fuel supply system named ultrasonic fuel supply system. The performance test of diesel automobile engine carried out to examine possibility of practical use of ultrasonic fuel supply system to test engine. This paper deals with the comparative results of performance test of diesel automobile engine in terms of smoke, HC, SFC, PS, thermal, efficiency, torque. Following are obtained result. 1) In naturally aspirated diesel engine, when we use ultrasonic fuel supply system output, fuel consumptions are improved and exhaust gas reduced significantly. 2) In turbo-charging diesel engine both using of ultrasonic fuel supply system and using of conventional injector, engine performance and exhaust gas temperature are almost constant. 3) In turbo-charging diesel engine, when we use ultrasonic fuel supply system, NOx are emitted approximately 3.5% higher than total average. 4) In turbo-charging diesel engine, when we use ultrasonic fuel supply system, smoke and CO are 17% and 11.8% improved respectively.

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A Study on the Ultrasonic Measurement for Damage Evaluation of Power Plant Bearing (발전용 베어링 손상평가를 위한 초음파 측정 연구)

  • Lee, Sang-Guk
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.1727-1732
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    • 2004
  • For the purpose of monitoring by ultrasonic test of the ball bearing conditions in rotating machinery, a system for their diagnosis was developed. ultrasonic technique is used to detect abnormal conditions in the bearing system. And various data such as frequency spectrum, energy and amplitude of ultrasonic signals, and ultrasonic parameters were acquired during experiments with the simulated ball bearing system. Based on the above results and practical application for power plant, algorithms and judgement criteria for diagnosis system was established.

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Assessment of Bearing Damage by Ultrasonic Measurement (초음파 측정에 의한 베어링손상 평가)

  • LEE SANG-GUK;LEE In-CHEOL
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2004.05a
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    • pp.395-400
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    • 2004
  • For the purpose of monitoring by ultrasonic test of the ball bearing conditions in rotating machinery, a system for their diagnosis was developed. ultrasonic technique is used to detect abnormal conditions in the bearing system. And various data such as frequency spectrum, energy and amplitude of ultrasonic signals, and ultrasonic parameters were acquired during experiments with the simulated ball bearing system. Based on the above results and practical application for power plant, algorithms and judgement criteria for diagnosis system was established. Bearing diagnosis system is composed of four parts as follows : sensing part for ultrasonic sensor and preamplifier, signal processing part for measuring frequency spectrum, energy and amplitude, interface part for connecting ultrasonic signal to PC using A/D converter, graphic display and software part for display of bearing condition and for managing of diagnosis program.

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A Study on the Wet Type Ultrasonic Flow-meter System Development (습식방식의 초음파 유량계 시스템 개발에 관한 연구)

  • Lee Eung-Suk;Kwon Oh-Hoon;Rho Myung-Hwan;Lee Hyung-Suk
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.12 s.243
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    • pp.1638-1644
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    • 2005
  • This paper suggests fur the study on a fluid velocity measuring system using ultrasonic transducer. In general, the time difference method to measure the distance between transducers has been known. In this paper, the practical technology for manufacturing ultrasonic flow meter system is studied using the time difference method. The ultrasonic transducer was designed and manufactured. The transmission and receiving algorithm for ultrasonic signal was studied. The ultrasonic flow measuring system was experimented in laboratory using a water reservoir for verifying the distance measuring accuracy. Finally, it was tested in flow calibration laboratory for the velocity measuring performance. The system, designed in this study, showed 0.3 mm resolution in distance measurement. For precise flow measurement, a high speed triggering algorithm is required for ultrasonic signal receiving.

A Study on the Performance of Diesel Automobile of Ultrasonic Fuel Supply System(I) -About the Droplet Size Distribution of Ultrasonic Fuel Supply System - (초음파(超音波) 연료공급장치용(燃料供給裝置用) 디젤자동차(自動車)의 성능(性能) 향상(向上) 관한 연구(I) -초음파 연료공급장치를 통과한 연료의 분무특성에 대하여-)

  • Choi, D.S.;Seol, J.H.;Ryu, J.I.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.2 no.1
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    • pp.1-8
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    • 1994
  • This study carried out to investigate the spray characteristics of diesel oil through out ultrasonic fuel supply system in comparison with conventional. Size of the droplets comprising diesel spray was measured by immersed liquid method at different positions along the spray axis. Droplets distribution diagram was ploted and Sauter Mean Diameter(SMD) was also calculated. The effects of the ultrasonic vibration and injection pressure on the droplet size distribution and SMD were investigated. As the ultrasonic vibration supply SMD decreases on the same injection pressure conditions with conventional injector's. But the effect of ultrasonic vibration decreases with injection pressure increasing.

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Global Ultrasonic Sensor System for Self-localization of an Indoor Mobile Robot (실내용 이동 로봇의 자기 위치 추정을 위한 전역 초음파 센서 시스템)

  • Jin, Jae-Ho;Yi, Soo-Yeong
    • Proceedings of the KIEE Conference
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    • 2002.07d
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    • pp.2421-2423
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    • 2002
  • A global ultrasonic sensor system for self-localization of an indoor mobile robot is proposed in this paper. By the global ultrasonic sensor system, it is meant several ultrasonic transmitters fixed at some positions in the world coordinate and the receiver in the moving coordinate of a mobile robot. In order to achieve the synchronization between an ultrasonic transmitter and receiver and to avoid the crosstalk among the ultrasonic transmitters, simple radio frequency transmitters and receivers are adopted. Experiments are carried out to verify the effectiveness of the proposed ultrasonic sensor system.

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