• Title/Summary/Keyword: Sensor Technique

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Model-Free Hybrid Fault Detection and Isolation For UAV Inertial Measurement Sensors (무인기 관성측정 센서의 비모델 복합 고장진단기법)

  • Kim, Seung-Keun;Kim, You-Dan
    • Journal of Institute of Control, Robotics and Systems
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    • v.11 no.3
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    • pp.200-206
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    • 2005
  • In this paper, a redundancy management system for aircraft is studied, and FDI (Fault Detection and Isolation) algorithm of inertial sensor system is proposed. UAV system cannot allow triple or quadruple hardware redundancy due to the limitations on space and weight. In the UAV system with dual sensors, it is very difficult to identify the faulty sensor. Also, conventional FDI method cannot isolate multiple faults in a triple redundancy system. In this paper, hardware based FDI technique is proposed, which combines a parity equation approach with the wavelet based technique, which is a model-free FDI method. To verify the effectiveness of the proposed FDI method, numerical simulations are performed.

Application of FBG Sensors to the Monitoring of Railway Bridges (철도교량 모니터링을 위한 FBG 센서의 응용)

  • Chung Won-Seok;Kang Dong-Hoon;Choi Eun-Soo;Lee Jun-Sun
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2006.04a
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    • pp.10-14
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    • 2006
  • FBG sensors are able to measure the strain of structures more easily and durable than electronic resistance gages and thus many researches are on the way to apply the FBG sensor for response monitering of infrastructures. This study investigates the deflection estimation technique using FBG sensors. Several FBG sensors are multiplexed in single optical fiber and installed. in parallel pairs along the length of the structure. The measured strains at the top and bottom of a cross section can be transferred to the curvature of the section which can be used to calculate its displacement. It has been demonstrated that the estimated deflections using the FBG sensor are compared well with the readings from displacement transducers. The results show that the proposed instrumentation technique is capable of estimating the vertical deflection of the structures for various loading conditions including impact and dynamic loads, which is crucial in the structural health monitoring.

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Design and Implementation of Flexible Sensor to Measure Mechanical Stiffness of Soft Particles (Soft Particle의 강성 측정을 위한 단순한 구조의 유연 물질 센서의 개발)

  • Ihn, Yong Seok;Yang, Minho;Koo, Ja Choon
    • The Journal of Korea Robotics Society
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    • v.11 no.3
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    • pp.133-139
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    • 2016
  • Increasing interest of human health, building bio-database (Bio DB) has been become a hot issue in life science. Consequently, Single Cell Analysis (SCA) which can explain biodiversity of lives has been a significant factor for building Bio DB. In numerous studies from these analyses, they have been showed that mechanical properties of cells can serve explanation of biological heterogeneity and criterion of disease states. Therefore, measuring mechanical properties of cells have great potential to be used in bio-medical applications. However, traditionally, many researchers have undergone difficult and time consuming work because handling small sized cells usually requires high-skilled technique. Thus, this paper shows robotized stiffness measurement technique using fixed ended beam sensor, precision motorized stage and substrate which have wall structure.

Development of embedded Home Automation System using Multi-sensor (다기능센서를 이용한 임베디드 홈오토메이션 시스템 개발)

  • Kim, In-Keong;Ryu, Jeong-Tak
    • Journal of Korea Society of Industrial Information Systems
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    • v.11 no.5
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    • pp.11-17
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    • 2006
  • Recently, IT industry by digital technique is improved gradually. Therefore many electronic appliance became the digital, and this is magnified gradually. The development of embedded home automation system combined embedded and internet technique is taking many interest. Specially in the times of the ubiquitous, excellent economically home automation system is preferred even in general family. Therefore, in this paper, we escape from monotonic control of home automation and draw a plan intelligent home automation to be developed.

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Development of On-machine Measurement System utilizing a Capacitive-type Sensor (정전용량형 센서를 이용한 기상계측시스템의 개발)

  • 김건희;박순섭;박원규;원종호
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.10a
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    • pp.391-395
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    • 2002
  • This paper described about the ultra-precision profile measurement of aspheric surfaces using contact probing technique. A contact probe has been designed as a sensing device to obtain measuring resolutions in nanometer regime utilizing a leaf spring mechanism and a capacitive-type sensor. The contact probe is attached on the z-axis during measurement while aspheric objects are supported on the single point diamond turning machine(SPDTM). The machine xz-axis motions are monitored by a set of two orthogonal plane mirror type laser interferometers. Experimental results show that the contact probing technique developed of On-machine Measurement System in this investigation is capable of providing a repeatability of 20 nanometers with a $\pm$20 uncertainty of 300 nanometers.

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A Study on the Characteristics of Giant Magneto Resistance using Multi Layers (다층막을 이용한 거대자기저항(GMR)의 특성 연구)

  • Kim, Byeong-Woo;Lee, Young-Seok
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.5
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    • pp.113-118
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    • 2008
  • We have developed an integrated giant magneto resistance using not only circuit but also integrating technique with semiconductor for automobile application. It has four elements used for giant magneto resistance sensor. Ni-Fe/Cu multi layers were prepared on a glass substrate by magnetron sputtering. The dependence of magneto resistance on the thickness of the Ni-Fe and Cu layers was investigated. The MR ratio showed a saturated a peak at Cu layer $10{\AA}$, Ni-Fe layer $50{\AA}$, where the MR ratio is about 8.7% at room temperature. By means of Ni-Fe multi film and specific integrating technique, these new giant magneto resistance sensor showed excellent resistance characteristics.

A Study on Motion Analysis for Increasing the Effectiveness of Resistive Exercise (저항성 운동의 효과 증대를 위한 동작 분석에 관한 연구)

  • Won, Chulho
    • Journal of rehabilitation welfare engineering & assistive technology
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    • v.11 no.3
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    • pp.231-238
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    • 2017
  • In this paper, we propose a method of analyzing exercise behavior to increase health care and exercise effect in personal fitness. In this study, a user wears a band-shaped acceleration sensor, an angular velocity sensor, and a motion sensor equipped with a geomagnetic module. Using the technique presented in this paper, we analyzed the motion of three resistive exercises which is consistent with previous studies. We have acquired a technique for processing personalized exercise information from the data generated in the resistive exercise situation.

A Study on the Relative Localization Algorithm for Mobile Robots using a Structured Light Technique (Structured Light 기법을 이용한 이동 로봇의 상대 위치 추정 알고리즘 연구)

  • Noh Dong-Ki;Kim Gon-Woo;Lee Beom-Hee
    • Journal of Institute of Control, Robotics and Systems
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    • v.11 no.8
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    • pp.678-687
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    • 2005
  • This paper describes a relative localization algorithm using odometry data and consecutive local maps. The purpose of this paper is the odometry error correction using the area matching of two consecutive local maps. The local map is built up using a sensor module with dual laser beams and USB camera. The range data form the sensor module is measured using the structured lighting technique (active stereo method). The advantage in using the sensor module is to be able to get a local map at once within the camera view angle. With this advantage, we propose the AVS (Aligned View Sector) matching algorithm for. correction of the pose error (translational and rotational error). In order to evaluate the proposed algorithm, experiments are performed in real environment.

Analytic Model for Performance Evaluation of Asynchronous MAC Protocol in Wireless Sensor Networks (무선 센서네트워크에서 비동기식 MAC 프로토콜의 성능분석을 위한 분석적 모델)

  • Jung, Sung-Hwan;Kwon, Tae-Kyoung
    • Journal of Korean Institute of Industrial Engineers
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    • v.35 no.4
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    • pp.248-256
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    • 2009
  • In this paper, under saturated traffic condition in a single-hop wireless sensor network, we present an analytic model that evaluates the performance of asynchronous MAC protocol which uses a preamble technique. Our model considers the impact of several important factors such as sleep cycle, the backoff mechanism and the number of contending nodes. After obtaining the cumulative backoff time of a sending node and expected delay of a receiving node, an iterative algorithm is presented for calculating the performance measures such as expected energy consumption usage per packet and latency. Simulation results show that the proposed analytic model can accurately estimate the performance measures under saturated traffic conditions.

Learning the nonlinearity of a camera calibration model using GMDH algorithm (GMDH 알고리즘에 의한 카메라 보정 모델의 비선형성 학습)

  • Kim, Myoung-Hwan;Do, Yong-Tae
    • Journal of Sensor Science and Technology
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    • v.14 no.2
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    • pp.109-115
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    • 2005
  • Calibration is a prerequisite procedure for employing a camera as a 3D sensor in an automated machines like robots. As accurate sensing is possible only when the vision sensor is calibrated accurately, many different approaches and models have been proposed for increasing calibration accuracy. Particularly an important factor which greatly affects the calibration accuracy is the nonlinearity in the mapping between 3D world and corresponding 2D image. In this paper GMDH algorithm is used to learn the nonlinearity without physical modelling. The technique proposed can be effective in various situations where the levels of noises and characteristics of nonlinear distortion are different. In simulations and an experiment, the proposed technique showed good and reliable results.