• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1020-1023
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• 2009

A purpose of this study measure the acceleration of operating KTX high speed train to find out something wrong to obtain reliable the acceleration measurement data. The existing measurement system come about a difference between measurement data of running off the track with the acceleration measurement data of operating KTX high speed train. Therefore, the measurement system needs make up for the weak points in the current system. This study analyze existing measurement system and the acceleration measurement data to introduce the synchronization of the existing measurement system and the acceleration measurement and will be reasonable to this sampling through field test.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1853-1857
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• 2005

In most of motor-driven motion control systems, an encoder is used to measure a position of the motor and the velocity information is obtained by measuring the position increment over a sampling period. The quantization effect due to limited resolution of the encoder induces some measurement errors, and consequently causes deterioration of the motion performance especially in low velocity. In this paper, we propose a gain-scheduled acceleration estimator which works in wider velocity range than the original acceleration estimator. We investigate and analyze characteristics of the velocity measurement mechanism which takes into account the quantization effect of the encoder. Next, we introduce the acceleration estimator and propose a gain-scheduled acceleration estimator. The bandwidth of the gain-scheduled acceleration estimator is automatically adjusted by the velocity command. Finally, its performance is evaluated by simulation and experiment, and the results are compared with those of a conventional method and the original acceleration estimator.

• Journal of ILASS-Korea
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• v.18 no.3
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• pp.132-139
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• 2013

Smoke emissions from light duty diesel vehicles were measured using light extinction method with the free acceleration test mode. The smoke emissions for each measurement cycle of the free acceleration method showed large variations according to driver's pedal pushing pattern. The smoke values for each measurement cycle initially increased and reach a peak value. Integration of the smoke emissions with time for each measurement cycle was performed to get a representative smoke value which was obtained by averaging the integrated results. Two kinds of integration time range were used. One is range over the whole measurement cycle of the free acceleration method. The other is only the acceleration range in the measurement cycle. Overall, variation of the representative smoke values obtained by the integration method was reduced comparing to the traditional representative smoke value which was obtained from a peak smoke value over the measurement cycle. Ten vehicles of the same model with 2.5 liter diesel engines, and seven vehicles of the same model with 2.7 liter diesel engines, were tested using the free acceleration test method.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.94.5-94
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• 2001

Unrestricted measurement method of three-dimensional walking distance utilizing body acceleration and terrestrial magnetism is discussed. The three-dimensional walking distance is derived by the integration of the three dimensional acceleration of foot during swing phase. Since the sensor system attached on the foot rotates during swing phase, the acceleration data measured on the foot include acceleration of gravity which causes inaccurate calculation of the velocity and the distance. Three gyros are used to compensate the rotation of the sensor system. Moreover, one geomagnetic sensor is employed to derive the heading direction of the subject Healthy volunteers performed ...

• Journal of the Korean Society for Precision Engineering
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• v.11 no.6
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• pp.109-116
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• 1994

Quickness and precision are the two most important requirements for an industrial scale used in production lines. In this paper, a new approach, "Dynamic-Mass measurement control System of Acceleration and Displacement(DMS-AD) sensing", is presented to improve some of drowbacks in conventional scales. The system, consisted of acceleration and displace- ment sensors, spring scale and microcomputer, is based on full utilization of dynamic mass measurement of acceleration and displacement via microcomputer-assisted real time monitoring. The rsulting system, when combined with appropriate dynamic mass estimation algorithm software, has shown its effectiveness in terms of two desirable characteristics required. required.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.10a
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• pp.527-532
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• 2010

This paper is concerned with the measurement of static and dynamic displacement by image processing(IP) and study for prediction method of velocity and acceleration. To measure the displacement visually, the measurement system consists of a telephoto zoom camera, ccd image device and a computer. The specific target on the white board is used to calculate the displacement of the structure. The captured image is then converted into a pixel-based data and then analyzed numerically. The limitation of the system depends on the image capturing speed and the pixel-size of image. In this paper, we developed for the displacement measurement using the image processing method. The proposed method enables us to measure the vibration measurement, velocity and acceleration directly without any contact. The current resolution of the displacement measurement is limited to 1/100 millimeter scale.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1546-1551
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• 2004

The laser Doppler technique is well-established as a velocity measurement technique of high precision for flow velocity. Recently, the laser Doppler technique has also been used to measure acceleration of fluid particles. Acceleration is interesting from a fluid mechanics point of view, since the Navier Stokes equations, specifically the left-hand-side, are formulated in terms of fluid acceleration. Further, there are several avenues to estimating the dissipation rate using the acceleration. However such measurements place additional demands on the design of the optical system; in particular fringe non-uniformity must be held below about 0.0001 to avoid systematic errors. Relations expressing fringe divergence as a function of the optical parameters of the system have been given in the literature; however, direct use of these formulae to minimize fringe divergence lead either to very large measurement volumes or to extremely high intersection angles. This dilemma can be resolved by using an off-axis receiving arrangement, in which the measurement volume is truncated by a pinhole in front of the detection plane. In the present study an optical design study is performed for optimizing laser Doppler systems for fluid acceleration measurements. This is followed by laboratory validation using a round free jet and a stagnation flow, two flows in which either fluid acceleration has been previously measured or in which the acceleration is known analytically. A 90 degree off-axis receiving angle is used with a pinhole or a slit.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.2
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• pp.112-119
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• 2011

This paper is concerned with the measurement of static and dynamic displacement by image processing(IP) and study for prediction method of velocity and acceleration. To measure the displacement visually, the measurement system consists of a telephoto zoom camera, CCD(charge coupled device) image device and a computer. The specific target on the white board is used to calculate the displacement of the structure. The captured image is then converted into a pixel-based data and then analyzed numerically. The limitation of the system depends on the image capturing speed and the pixel-size of image. In this paper, we developed for the displacement measurement using the image processing method. The proposed method enables us to measure the vibration displacement, velocity and acceleration directly without any contact. The current resolution for the displacement measurement can be seen from the results.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.1043-1047
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• 2003

Most of the measurement and the evaluation of hand-transmitted vibration have been performed by using a small size single axis accelerometer between the handle and the hand palm or a three axis accelerometer attached on an adapter outside the hand(indirect measurement). It is most desirable for the correct evaluation of hand-transmitted vibration form the power tool handle to measure the acceleration between the handle surface and the hand palm in the three axis(direct measurement) as recommended in ISO 5349-1. In the study three axes acceleration measurement device was developed of which the thickness was less than 7mm so that it can be placed between the handle and the palm without any inconvenience during the measurement. To verify the performance of the developed device, measured acceleration by the two methods, direct and indirect, were compared in the study.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.5
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• pp.150-157
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• 2020

In this study, an algorithm was developed to validate the seismic acceleration measurement data of the seismic acceleration measurement system using measurement data from public buildings currently in operation. Through the results of the study, an algorithm was developed to detect errors and abnormalities in the measurement data itself and the process of generating real-time data (MMA/sec) and event measurement data (MiniSEED), which are the main data generated by the system, and the basic data for determining the direction of inspection through measurement data analysis. It is expected that this will be used as a guideline to determine whether or not the seismic acceleration measurement system, which was managed as receiving/not receiving, is inspected and abnormal types of conditions.