• Title/Summary/Keyword: Displacement meter

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Driving Characteristics of Pneumatic Cylinder with Relief Valve Cushion Devices (릴리프밸브 쿠션기구 내장형 공기압 실린더의 구동 특성)

  • Kim, Do Tae
    • Journal of Drive and Control
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    • v.13 no.4
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    • pp.7-13
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    • 2016
  • This paper presents the meter-out and meter-in speed control characteristics of a pneumatic cylinder with relief valve type cushion device. The piston displacement and velocity are measured to investigate high speed driving performance with variation of the pressure setting in relief valve, air supply pressure, load mass, the supply and exhaust flow rate from the cylinder. Also, the internal pressures and temperatures driving pressure and cushion chamber are measured. The piston displacements and velocities of meter-out and meter-in control are compared experimentally determined data. A comparison experimental data meter-out and meter-in control show that a relief valve type cushion device is suitable for high speed pneumatic cylinders. The desired response characteristics of piston displacement and velocity are satisfactory adjust the pressure setting of a relief valve with varying system parameters such as air supply pressure, load mass and controlled flow rate.

Comparative study on displacement measurement sensors for high-speed railroad bridge

  • Cho, Soojin;Lee, Junhwa;Sim, Sung-Han
    • Smart Structures and Systems
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    • v.21 no.5
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    • pp.637-652
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    • 2018
  • This paper presents a comparative study of displacement measurement using four sensors that are being used in the field: they are a ring gauge, a laser Doppler vibrometer (LDV), a vision-based displacement measurement system (VDMS), and an optoelectronic displacement meter (ODM). The comparative study was carried out on a brand-new high-speed railroad bridge designed to produce displacements within a couple of millimeters under the loading of a high-speed train. The tests were carried out on a single-span steel plate girder bridge two times with different train loadings: KTX and HEMU. The measured displacement is compared as raw and further discussion was made on the measurement noise, peak displacement, and frequency response of four sensors. The comparisonsare summarized to show the pros and cons of the used sensors in measuring displacement at a typical high-speed railroad bridge.

Displacement Measurement of Cable Stayed Bridge using Digital Image Processing (디지털 영상처리를 이용한 사장교의 변위 측정)

  • Son, Byung Jik;Jeon, Seung Gon;Heo, Gwang Hee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.5
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    • pp.237-242
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    • 2016
  • This paper introduces a method of measuring the displacement of a cable-stayed bridge using digital image processing (DIP). The validity of the DIP technique was confirmed by comparing the results with those obtained using a displacement meter and ANSYS analysis. The normalized cross-correlation (NCC) coefficient was used. 100 kgf and 200 kgf loading experiments were carried out, which showed that when the displacement is large, the reliability of the DIP technique is increased. That is, when the load was increased from 100 kgf to 200kgf, it decreased from 31% to 14% compared to the ANSYS results and from 14% to 4% compared to the displacement meter results. Therefore, the image processing method is able to measure the displacement sufficiently accurately.

The Study on Variation Minimization Method of Reflection Signal Level for High Precision Laser Displacement (고정밀 레이저 변위를 위한 레이저 반사 신호 레벨의 변동 최소화 기법에 관한 연구)

  • Bae, Young-Chul;Park, Jong-Bae;Cho, Eui-Joo;Kang, Ki-Woong;Kang, Keon-Il;Kim, Hyeon-Woo;Kim, Eun-Ju
    • The Journal of the Korea institute of electronic communication sciences
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    • v.3 no.1
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    • pp.12-18
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    • 2008
  • In this research, we proposed a method for high precision measurement than laser displacement measurement. The proposed method finds the causes of error due to change in reflected laser signal level reflected from an object and compensation, and we designed this by applying laser displacement meter.

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A Study on Development of a Noncontact Precision Flow-meter Using MR Sensor and PIC (MR 센서와 PIC를 이용한 비접촉식 정밀 유량계 개발에 관한 연구)

  • 이승희;이민철;고석조;장용석;최문호
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1063-1066
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    • 2003
  • A flow-meter and its measurement controller was developed for a hydraulic system. This study, for development of positive displacement flow-meter, consist of PIC(Peripheral Interface Controller) controller with MR(Magneto-resistive) sensors. This flow-meter is used valve position indicator for valve control system by hydraulic. The MR sensors are used for the rotation of OVAL gear that detecting device. In the ship environments, consideration that necessary explosive proof. Thus electro device or electro flow-meter needs explosion design for electric circuit. We designed noncontact type flow-meter and evaluated the safety and measuring abilities.

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ANALYSIS OF THE FIT IN THE IMPLANT PROSTHESIS USING A LASER DISPLACEMENT METER AND THREE-DIMENSIONAL FINITE ELEMENT METHOD

  • Kwon Ho-Beom;Kim Yung-Soo;Kim Chang-Whe
    • The Journal of Korean Academy of Prosthodontics
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    • v.39 no.6
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    • pp.611-624
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    • 2001
  • A precise fit of the implant prosthesis is one of the most important factors in preventing mechanical complications. To analyze the degree of the misfit of implant prosthesis, a modal testing experiment was accomplished. And. to interpret the modal testing analysis mathematically, three-dimensional finite element models were established. In the experimental modal testing analysis, with a laser displacement meter, FFT analyzer, impact hammer, etc., natural frequencies of the models with various degree of prosthesis fit were determined after the frequency response function were calculated. In the finite element analysis, the natural frequencies and mode shapes of the models which simulated those of experimental modal testing were computed. The results were as follows: 1. Natural frequencies of the prosthesis-abutment were related to the contact state between components. 2. In the modal testing experiment, the natural frequencies increased from $50{\mu}m$ to $200{\mu}m$ gap and reached a plateau. 3. In the finite element analysis, the natural frequencies decreased gradually according to the in crease of the gap size. 4. In the finite element analysis, the mode shapes of model 1 with misfitting prosthesis showed different patterns from those without misfitting prosthesis. 5. The devices including a laser displacement meter used in this study were useful for measuring the natural frequencies of an implant prosthesis which had various degrees of fit.

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A Study on the Torsional Vibration Measurement of the Horizontal Shaft with Disks (단을 가진 수평축의 비틀림진동 측정에 관한 연구)

  • 박일수;안찬우;김중완
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.04a
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    • pp.3-8
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    • 1997
  • This parer was presented for the experimental results of torsional vibrations of the horizontal rotating shaft with three disks. The torsional vibrations meter used is a laser system for non-contact measurement of torsional angular vibration velocity and torsional angular vibration displacement. The distance between the disks war changed; the one that had 76mm of disk distance war called basic model, and another that had 106mm of disk distance wide model, and other that had 46mm of disk distance narrow model. In each model, outer diameter of disk was 40mm. And 45mm, or 50mm was also used to extend the effective range of frequencies. The angula vibration displacement and the angular vibration velocity in its torsional vibration were measured to obtain the stable and the unstable regions.

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A Study on the Meter-Out and Meter-In Speed Control Characteristics in Pneumatic Cushion Cylinders (공기압 쿠션 실린더의 미터아웃/미터인 속도제어 특성에 관한 연구)

  • Kim, Do-Tae
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.22 no.1
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    • pp.1-7
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    • 2013
  • Pneumatic cylinders are widely used to actuators in automatic equipments because they are relatively inexpensive, simple to install and maintain, offer robust design and operation, are available in a wide range of standard sizes and design alternatives. This paper presents a comparative study among the dynamic characteristics of meter-out and meter-in speed control of pneumatic cushion cylinders with a relief valve type cushion mechanism. Because of the nonlinear differential equations and a requirement for simultaneous iterative solution in a mathematical model of a double acting pneumatic cushion cylinder, a computer simulation is carried out to investigate pressure, temperature, mass flow rate in cushion chamber and displacement and velocity time histories of piston under various operating conditions. It is found that the piston velocity and pressure response in meter-in speed control are more oscillatory than with meter-out those when pneumatic cushion cylinders are driven at a high-speed. In meter-out speed control, the effective area of the flow control valve is larger than that of meter-in, and the supply pressure has to be much higher than the pressure required to move the load because it has also to overcome the back pressure in cushion chamber.

Design and Performance Analysis of Zoom-FFT Based FMCW Radar Level Meter (Zoom-FFT 기반 FMCW 레이더 레벨미터의 설계 및 성능분석)

  • Sanjeewa, Nuwan;Kim, Won-Ho
    • Journal of Satellite, Information and Communications
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    • v.9 no.2
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    • pp.38-44
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    • 2014
  • This paper presents design of a FMCW (Frequency Modulated Continuous Wave) level meter as well as simulation result of the designed system. The system is designed to measure maximum range of 20m since FMCW radar can be used for measuring short range distance. The distance is measured by analyzing the beat signal which is generated as result of mixing transmitting signal with the reflected received signal. The Fast Fourier Transform is applied to analyze the beat signal for calculating the displacement and Zoom FFT technique is used to minimize measurement error as well as increase the resolution of the measurement. The resolution of the measurement of the designed system in this paper is 2.2mm and bandwidth of 1.024GHz is used for simulation. Thus the simulation results are analyzed and compared in various conditions in order to get a comprehensive idea of frequency resolution and displacement resolution.

The Experimental and Basic Study on Torsional Vibration of Horizontal Rotating Shaft using a Laser Measuring Equipment (레이저 계측기를 이용한 축의 비틀림 진동에 관한 실험적 기초 연구)

  • Park, I.S.
    • Journal of Power System Engineering
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    • v.13 no.1
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    • pp.33-38
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    • 2009
  • In this study, the nose of cam in the automobile engine was modelled into circular disk to analyze the torsional vibration of the cam shaft. The distance between disks was fixed, but the diameter of disks was changed. The torsional vibration of the cam shaft was studied experimentally by the motion of the modelled disk with changing the disk diameter. And the sizes of the modelled disk were selected not to show the natural frequencies over all the experimental ranges. The torsional vibration meter used in this study has a laser system with non-contact measurement method, which can measure both torsional angular vibration velocity and torsional angular vibration displacement simultaneously. The Experimental analysis shows that the characteristics of the torsional vibration in the horizontal rotating shaft can be considerably affected by the arrangement of the modelled disks.

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