• 국제초고층학회논문집
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• 제6권3호
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• pp.207-216
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• 2017

Installing accelerometers in a building is an effective way to know how the building shakes when an earthquake happens. In this paper, we will introduce an example of an analysis that captures the acceleration reduction effect of the vibration damping device using data observed by the accelerometer at Roppongi Hills Mori Tower in Minato-ku, Tokyo, during the Great East Japan Earthquake on March 11, 2011. Moreover, as the latest effort, from the standpoint of a developer who builds and operates a number of high-rise buildings in Japan, where frequent earthquakes are experienced, a system for real-time processing of accelerometer data was developed to instantly diagnose the degree of damage to high-rise buildings, and the actual system of earthquake damage health monitoring is discussed. This system is currently in operation in twelve high-rise buildings including Roppongi Hills Mori Tower.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1998년도 춘계학술대회논문집; 용평리조트 타워콘도, 21-22 May 1998
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• pp.173-178
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• 1998

An automatic Q. C. tester for a production line of electric grinder is developed using vibration signals. The methods of measuring and analyzing the vibration signals are found through several experiments at laboratory and production line. The experiments show that checking a vibration signal at running condition only, without any sound signal, is enough to judge whether the product is good or not. The Q. C. tester is made of accelerometer and PC. Measured vibration signal using accelerometer is transmitted to PC through A/D board. Vibration level are calculated using FFT algorithm in PC for already selected five frequency bands, which can specify the cause of fault. The Judging criteria of vibration levels of each bands are decided through a lot of experiment with the comparison of manual judgement.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.1047-1051
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• 2004

Charge amplifier systems benefit from the very wide dynamic range of PE accelerometers by offering flexibility in adjusting the electrical output characteristics such as sensitivity and range. They are well suited for operation at high temperatures. Modern charge systems feature improved low noise operation, simplified digital controls, and dual mode operation for operation with charge or IEPE voltage mode sensors. high impedance circuitry is not well suited for operation in adverse field or factory environments. The resolution of a PE accelerometer may not be specified or known since noise is a system consideration determined by cable length and amplifier gain. IEPE accelerometrs operate from a constant current power source, provide a high-voltage, low-impedance, fixed mV/g output. They operate through long, ordinary, coaxial cable in adverse environments without degradation of signal quality. They have limited high temperature range. IEPE sensors are simple to operate. Both resolution and operating range are defined specifications. Cost perchannel is lower compared to PE systems since low-noise cable and charge amplifiers are not required.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.28-31
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• 2014

This paper is concerned with the active vibration control of washing machine. To this end, a new control algorithm utilizing an acceleration signal as a sensor signal is newly developed based on the principle of a dynamic absorber. The resulting control algorithm was implemented digitally on the DSP board. The accelerometer and the active linear actuator were used as sensor and actuator for the active vibration control of washing machine. Experimental results show that the proposed control algorithm can be effectively used for a controller which uses an accelerometer.

• 대한안전경영과학회지
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• 제14권1호
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• pp.87-93
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• 2012

The purpose of this study suggests a personalized algorithm of physical activity energy expenditure prediction through comparison and analysis of individual physical activity. The research for a 3-axial accelerometer sensor has increased the role of physical activity in promoting health and preventing chronic disease has long been established. Estimating algorithm of physical activity energy expenditure was implemented by using a tri-axial accelerometer motion detector of the SVM(Signal Vector Magnitude) of 3-axis(x, y, z). A total of 10 participants(5 males and 5 females aged between 20 and 30 years). The activities protocol consisted of three types on treadmill; participants performed three treadmill activity at three speeds(3, 5, 8 km/h). These activities were repeated four weeks.

• 반도체디스플레이기술학회지
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• 제9권2호
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• pp.41-47
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• 2010

In this paper we suggest an improvement upon the previous method of estimating a body's attitude. This paper presents a method that overcomes the shortcomings of previous studies. Applying the method of separating the acceleration of gravity component from the accelerometer's output improves the performance of the attitude estimation and extends the scope. In order to apply the method of the attitude estimation in an actively moving body, a new acceleration value containing the acceleration of gravity is calculated. This paper also proposes the method which minimizes the estimation error in estimating the moving body's attitude which is changing rapidly. Finally, this paper suggests a method that detects the gyroscope's drift and compensates for this drift using accelerometer. Applying the method improves the performance of the attitude estimation.

• 한국자동차공학회논문집
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• 제11권1호
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• pp.128-136
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• 2003

In today's design trend of vehicle structure, crush zone is fiequently reinforced by adding a box-shaped sub-frame in order to avoid an excessive deformation against a high-speed offset barrier such as EU Directive 96/97 EC, IIHS offset test. That kind of vehicle structure design results in a relatively monotonic crash pulse for airbag ECU(Electronic Control Unit) located at non-crush zone. As for an angular crash event, the measured crash signal using a single-axis accelerometer in a longitudinal direction is usually weaker than that of frontal barrier crash. Therefore, it is not so easy task to achieve a satisfactory crash discrimination performance for offset and angular crash events. In this paper, we introduce a new crash discrimination algorithm using an electronic X-Y 2-axis accelerometer in order to improve crash discrimination performance especially for those crash events. The proposed method uses a crash signal in lateral direction(Y-axis) as well as in longitudinal direction(X-axis). A crash severity measure obtained from Y-axis acceleration is used to improve the discrimination between fire and no-fire events. The result obtained by the proposed measure is logically ORed with an existing algorithm block using X-axis crash signal. Simulation and pulse injection test have been conducted to verify the performance of proposed algorithm by using real crash data of a 2,000cc passenger vehicle.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2008년도 춘계종합학술대회 A
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• pp.229-232
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• 2008

A Neural network classification of human activity data is presented. The data acquisition system involves a tri-axial accelerometer in wireless sensor network environment. The wireless ad-hoc system has the advantage of small size, convenience for wearability and cost effectiveness. The system can further improve the range of user mobility with the inclusion of ad-hoc environment. The classification is based on the frequencies of the involved activities. The most significant Fast Fourier coefficients, of the acceleration of the body movement, are used for classification of the daily activities like, Rest walk and Run. A supervised learning approach is used. The work presents classification accuracy with the available fast batch training algorithms i.e. Levenberg-Marquardt and Resilient back propagation scheme is used for training and calculation of accuracy.

• 제어로봇시스템학회논문지
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• 제11권12호
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• pp.1045-1050
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• 2005

This paper describes a design experience of a low-cost 6 DOF spatial tracker system where relative low accuracy and relatively long ranges, wireless communication will be achieved by means of low cost accelerometers and gyros with contemporary microprocessor. However, there are two key problems; one is the bias drift problem and the other is that single or double integration of acceleration signal suffers not only from noise but also from nonlinear effects caused by gravity. To be specific, beginning and stopping of hand motions needs to be accurately detected to initiate and terminate integration process to get position and pose of the hand from accelerometer and gyro signals, since errors due to noise and/or hand-shaking motions accumulated by integration processes. Several experimental results are shown to validate our proposed algorithms.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.130.4-130
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• 2001

In this paper, a measurement system of moving distance is developed. The error compensation method is also proposed using the characteristics of walking motion. As personal navigation systems and multimedia systems are emerging into the commericial market, men´s moving distance is considered as one of the important information. GPS offers the information easily but GPS can be used only when the satellites are visible. INS can calculate the moving distance anywhere but error is increased with time due to the sensor bias. In this paper, to detect the human walking distance a measurement system of moving distance only using low-cost accelerometer is developed. The sensor bias is estimated and compensated using the walking motion characteristics. The performanced of the proposed system is verified by experiment.