• Title/Summary/Keyword: 충격 감지

Search Result 73, Processing Time 0.029 seconds

Door-Lock System to Detect and Transmit in Real Time according to External Shock Sensitivity (외부 충격 감도에 따른 실시간으로 탐지하고 전송하는 Door-Lock 시스템)

  • Jeon, Byung-Jin;Han, Kun-Hee;Shin, Seung-Soo
    • Journal of the Korea Convergence Society
    • /
    • v.9 no.7
    • /
    • pp.9-16
    • /
    • 2018
  • The purpose of this study is to prevent the malicious user from breaking the door-lock due to physical impact. If it matches the analog displacement value set in the door-lock system, it protects the body and property by transmitting damage information in real time to the manager smart phone. The research suggests a system that transmits damage information in real time to registered users when door-lock is damaged by physical impact. Then compare the impact information sensed by the door lock with the data of the sensitivity control unit. In the web server of the proposed system, after impact information transmitted from Door-Lock is stored in the DB, if the impact information is larger than the shock detection transmission reference value stored in the DB, it is transmitted to the administrator in real time by SMS module so that illegal access information.

Fatigue Damage Detection and Vibration Sensing Using Intensity-Based Optical Fiber Sensors (광강도형 광섬유센서를 이용한 피로손상 및 진동감지)

  • 양유창;전호찬;한경섭
    • Composites Research
    • /
    • v.13 no.1
    • /
    • pp.89-97
    • /
    • 2000
  • Fatigue damage detection and vibration sensing for a laminated composites and impact location detection for a steel beam have been carried out using optical fiber sensor. Intensity based optical fiber sensor is constructed by placing two cleaved fiber end in a hollow glass tube, and multiple reflection within the cavity is considered. Fatigue signals are measured by embedded optical fiber, surface mounted optical fiber sensor and strain gage simultaneously. For vibration sensing, optical fiber sensor is mounted on the carbon fiber composite beam and its response to free vibration and forced vibration is investigated. In impact location detection, two optical fiber sensors are used and the information obtained from two sensors is arrival time delay of vibration caused by impact. Impact location can be calculated from this time delay. The obtained results show that the intensity based optical fiber sensor provide reliable data during long-term fatigue loading, unlike strain gage which deteriorate during the early part of the fatigue test. Optical fiber sensor signals coincide with gap sensor in vibration sensing. The precise locations of impact can be detected within 4.1% error limit.

  • PDF

Vibration Sensing and Impact Location Measurement Using Intensity-Based Optical Fiber Vibration Sensor (광강도형 광섬유 진동센서를 이용한 진동감지 및 충격위치 측정)

  • 양유창;황운봉;박현철;한경섭
    • Composites Research
    • /
    • v.13 no.5
    • /
    • pp.1-9
    • /
    • 2000
  • An intensity-based optical fiber vibration sensor is applied to monitor the structural vibration and detect impact locations on a plate. Optical fiber vibration sensor is constructed by placing two cleaved fiber end, one of which is cantilevered in a hollow glass tube. The movement of the cantilevered section lags behind the rest of the sensor in response to an applied vibration and the amount of light coupled between the two fibers is thereby modulated. For vibration sensing, optical fiber vibration sensor is mounted on the carbon fiber composite beam and its response is investigated to free and forced vibration. In impact location detection, four optical fiber vibration sensors whose location is predetermined are placed at chosen positions and the different arrival times of impact-generated vibration signal are recorded by an FFT analyzer. Impact location can be calculated from these time delays. Experimental results show that optical fiber vibration sensor signals coincide with gap sensor in vibration sensing. The precise location of impact can be detected on an acrylate plate.

  • PDF

A Study on Impact Monitoring Using a Piezoelectric Paint Sensor (압전 페인트 센서를 활용한 충격 모니터링 활용 방안)

  • Choi, Kyungwho;Kang, Donghoon;Park, Seung-Bok;Kang, Lae-Hyong
    • Journal of the Korean Society for Nondestructive Testing
    • /
    • v.35 no.5
    • /
    • pp.349-357
    • /
    • 2015
  • The piezoelectric paint sensor is a paint type sensor comprising of an epoxy and piezoelectric powder, which is the main component of a piezoelectric material. This sensor can be easily attached to any type of structure as compared to other sensors because it is viable to directly apply it on structures, as in the case with a typical paint. In this study, the capability of piezoelectric paint sensor for impact detection was evaluated. In Particular, the applications of the piezoelectric paint sensor for railroad vehicles were considered. There have been various cases reported about the damages caused by flying gravel to the under-cover of the railroad vehicle during operation. In order to prevent this, real-time monitoring of the large under-cover surface of the railroad vehicle is unavoidable. Under the assumption of vehicle application, sensor sensitivities were measured after multiple and prolonged exposure to thermal cycle environment $-20{\sim}60^{\circ}C$). Sensitivity evaluation of paint sensor under environmental conditions was conducted in an aluminum specimen. In results, despite the small variations in sensitivity, we could confirm the applicability of this paint sensor for impact detection even after a severe environmental exposure test.

Rain Sensor using Scattered Light Outside Waveguide (광도파관 외부산란광을 이용한 우적감지 센서)

  • Choi, Kyoo-Nam
    • Journal of the Institute of Electronics Engineers of Korea SC
    • /
    • v.48 no.2
    • /
    • pp.22-27
    • /
    • 2011
  • Rain sensor detecting the presence of rain outside windshield glass of automobile by receiving scattered light from rain drops is proposed. Rain sensor using windshield glass as light waveguide required precision optical apparatus to inject light signal into windshield glass, and it was susceptible to outside shock and vibration, resulting malfunction, which altered optical coupling ratio. Proposed rain sensor, which detected scattered light from rain drops outside optical waveguide, did not require optical components because it did not need to inject light signal into light waveguide. This was advantageous because the sensor was less effected by shock and vibration. Fabricated rain sensor using scattered light outside waveguide responded not only to rain drops but also mist particles under simulated rain conditions using spraying nozzle, thus it showed prospects as rain sensor for automobile application.

Detection of High-Velocity Impact Damage in Composite Laminates Using PVDF Sensor Signals (고분자 압전 필름 센서를 이용한 복합재 적층판의 고속 충격 손상 탐지)

  • Kim Jin-Won;Kim In-Gul
    • Composites Research
    • /
    • v.18 no.6
    • /
    • pp.26-33
    • /
    • 2005
  • The mechanical properties of composite materials may severely degrade in the presence of damage. Especially, the high-velocity impact such as bird strike, a hailstorm, and a small piece of tire or stone during high taxing, can cause considerable damage to the structures and sub-system in spite of a very small mass. However, it is not easy to detect the damage in composite plates using a single technique or any conventional methods. In this paper, the PVDF(polyvinylidene fluoride) film sensors were used for monitoring high-velocity impact damage initiation and propagation in composite laminates. The WT(wavelet transform) and STFT(short time Fourier transform) are used to decompose the sensor signals. A ultrasonic C-scan and a digital microscope are also used to examine the extent of the damage in each case. This research shows how various sensing techniques, PVDF sensor in particular, can be used to characterize high-velocity impact damage in advanced composite.

A Study of the Optical Fiber Sensor for sensing impact and pressure (광섬유를 이용한 충격 및 압력 센서에 관한 연구)

  • 양승국;조희제;이석정;전중성;오상기;김인수;오영환
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.7 no.1
    • /
    • pp.129-135
    • /
    • 2003
  • Optical fiber has many advantages, such as high reliability, long lifetime, immunity to the electromagnetic interference, high speed response and low cost. In this study, we proposed and developed an optical fiber impact and pressure sensor for prevention of accident which occurs in the automatic system or auto door. The principle of the sensor is to detect different optical intensity caused by variation of a speckle pattern due to the external perturbation. Speckle pattern appears at the end of a multimode fiber in which coherent beam propagates. The fabricated sensor in this study was tested. As a result of experiments, amplitude of the output signal isn't linear, but it has sufficient sensitivity for a sensor. Moreover, we can control sensitivity of the sensor by an amplifier at receiver. It has several advantages which are ability of detection at all point on the multimode fiber, large sensitive area, and many application areas for a sensing impact and pressure.

Monitoring of Low-velocity Impact Damage Initiation of Gr/Ep Panel 7sing Piezoeleetric Thin Film Sensor (압전필름센서를 이용한 복합재 평판의 저속충격 손상개시 모니터링)

  • 박찬익;김인걸;이영신
    • Composites Research
    • /
    • v.15 no.2
    • /
    • pp.11-17
    • /
    • 2002
  • The piezoelectric thin film sensor can be used to interpret variations in structural and material properties, e.g. for structural integrity monitoring and assessment. To illustrate one of this potential benefit, PVDF (polyvinylidene fluoride) film sensors are used for monitoring impact damage in Gr/Ep composite panels. Both PVDF film sensors and strain gages are attached to the surface of Gr/Ep specimens. A series of impact tests at various impact energy by changing impact mass the height are performed on the instrumented drop weight impact tester. The sensor responses are carefully examined to predict the onset of impact damage such as indentation, matrix cracking, and delamination, etc. Test results show that the particular waveforms of sensor signals implying the damage initiation and development are detected above the damage initiation impact energy. As expected, the PVDF film sensor is found to be more sensitive to impact damage initiation event than the strain gage.

Study on real time monitoring to detect third party damage using vibration signal (진동신호를 이용한 타공사 조기 감시 기술 연구( I ))

  • Cho S.H.;Jeon K.S.;Park K.W.;Cho Y.B.;Li S.Y.;Kyo Y.T.
    • Journal of the Korean Institute of Gas
    • /
    • v.4 no.1 s.9
    • /
    • pp.1-8
    • /
    • 2000
  • Third party damage is one of the causes intrimiting the safety of a buried pipelines and it is very important to detect third party damage on pipelines as soon as possible. The purpose of this study is whether third-party damage can be detected by accelerometer sensor and how far the third-party damage signal can propagate. And a pilot experiment was carried out in order to find third-party damage location. As a result, the detected signal's spectum is high frequency at short distances, as the distance is far, the signals in high frequency range are attenuated and those in low frequency range remain. It was also proved that third-party damage within 5.3km distance can be detected by monitoring vibration signals.

  • PDF

Kiosk for the Visually Impaired using Voice Recognition (음성인식 기능을 이용한 시각장애인용 키오스크)

  • Kim, Dae-Young;Lee, Ah-Hyun;Lee, Gun-Haeng;Kim, Se-Hyun;Lee, Boong-Joo
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.17 no.5
    • /
    • pp.873-882
    • /
    • 2022
  • In this paper, we studied the voice recognition system kiosk for convenience, thinking that the kiosk widely used in modern society should compensate for the inconvenience of using by the visually impaired. Using ultrasonic sensor and PIR(Passive Infrared), it recognizes the visually impaired within the range of 80cm-40cm, introduces the kiosk through the MP3 module and induces them to come closer. Also, when the visually impaired within 40cm is recognized, the product description and order are guided through the MP3 module. A recording-based data voice recognition system and a kiosk that outputs desired items through servo motors were studied. A kiosk for the convenience of the visually impaired was manufactured through operation and optimization experiments of PIR, ultrasonic, voice recognition, and shock sensor for the manufactured voice recognition kiosk. Finally, it was confirmed that security can be strengthened by using shock sensors and emergency bells to enhance security.