• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3227-3229
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• 1999

수신된 초음파 파형이 표준 파형과 정합되는 시간을 수신 시점으로 사용함으로써 정확한 거리측정을 가능하게 하는 초음파 센서 거리계의 성능 개선을 제안하였다. 근거리 측정용으로 많이 사용되는 초음파센서는 다른 거리측정 시스템에 비해 하드웨어 구현이 용이하고 가격이 저렴한 장점이 있으나 센서 수신부측 Limit 회로의 threshold level의 선택 문제에 따른 거리 측정의 오차와 소음에 의한 거리 측정 오차가 매우 큰 문제가 되고 있다. 본 논문에서는 수신된 초음파 파형에 표준 파형을 정합하여 최대의 정합값을 가지는 시점을 수신 시간으로 간주하여, 소음환경비서도 거리 측정이 가능한 파형 정합 방법을 제한하였다. 본 논문의 실험을 통하여, 잡음이 심한 소음환경에서도 제안한 파형 정합 방법이 Threshold 방법 보다 초음파센서 거리 측정 성능이 개선됨을 확인할 수 있었다.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.1
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• pp.95-100
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• 2011

The test was done on cars travelling at speeds of 20km/h, 60km/h and 100km/h, the performance testing mode for chassis dynamometer. In this test, the secondary waveform were measured, including those using faulty MAP sensors, oxygen sensors and spark plugs. The results from these measurements and their analysis of secondary waveform can be summarized as follows: 1) The secondary waveform measured from the faulty oxygen sensor showed a lot of noise around peak voltage and in the rising and falling sections during spark line which means that the air fuel mixture was non-homogeneous. 2) The secondary waveform from the faulty MAP sensor showed the worst shape compared to other sensors, including variation of spark line, state of air-fuel mixture and velocity of flame front. 3) The spark line time of secondary waveform using a faulty spark plug displayed the shortest and smallest energy spark line, which means that a misfire occurred.

• Journal of IKEEE
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• v.26 no.1
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• pp.43-49
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• 2022

This paper compares the sensorless control performance according to the applied voltage waveform by injecting sinusoidal, triangular, and square waveform in the harmonic injection sensorless control method. By injecting various voltage shape waveform with a frequency of 1kHz, the error amount of the estimated angle for each waveform is compared and analyzed. For the experiment, the HILS(hardware in the loop simulation) system was used. The hardware is the control board, and the inverter and motor models implemented in Simulik are located in the real-time simulator. The control algorithm is implemented by the FPGA control board, which includes a PWM interrupt service routine with a frequency of 10 kHz, harmonic injection and position detection sensorless algorithm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.1
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• pp.83-90
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• 2020

A commercial flow measurement radar sensor estimates a quantity of flowed water using surface flow rate. In this way, the amount of water flowing per unit time cannot be measured accurately because of using an estimation result and it can't response environmental changes. For more accurate flow measurements we need width of waterway, water level and distance that water moved per unit time. Commonly two sensors are used to measure water level and flow rate. In this paper, we propose a method to simultaneously measure the water level and surface flow velocity using a single FMCW radar sensor and design the transmission waveform. In order to verify the waveform design, received signal is modelled based on transmission waveform. In addition, we consider phenomenons and problems that may occur in signal processing.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.5
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• pp.151-156
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• 2013

The experiment was done on cars travelling at the speeds of 20km/h, 60km/h and 100km/h using the performance testing mode for chassis dynamometer. In this experiment, the relativity between the secondary waveform coming from ignition coil and exhaust emissions were measured in case of cars with failures, in oxygen sensor, spark plugs. The following results obtained by analysis of the relativity between the secondary waveform and exhaust emissions. 1) When the oxygen sensor is failure, the average value of CO emission measured was 6.8 times higher than the standard CO emission value and the average value of HC emission measured was 2.3 times higher than the standard emission level. 2) When engine parts are in failure, more fuel enters the cylinder due to longer opening duration of injector, and it tended to make CO and HC emission values increase. 3) Combustion duration, the shape of flame propagation during spark line, and the size of the discharge-induced energy were the three main elements that directly cause variations in CO and HC emission values.

• Journal of the Korean Magnetics Society
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• v.22 no.1
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• pp.27-31
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• 2012

Two radially arterial pulses of both hands using the prototype of a clamping clip pulsimeter equipped with permanent magnet and Hall device are compared and analyzed. The phase difference of two pulse wave signals is dominantly presented from the simultaneous measuring clinical pulse wave signals for twenty two male participants at their 20's. It is possible to analyze that the fast and slow pulse wave for right hand and left hand depend on the muscle property of arms rather than the total length of blood vessel due to cardiovascular circulatory system.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2007.06a
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• pp.259-262
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• 2007

현재의 전자제어 차량 정비에 있어서 각종 센서 및 엑츄에이터의 전압파형을 측정, 분석하여 원인을 진단하는 사례가 일반화 되어 가고 있다. 이러한 추세에 맞추어, 자동차 정비 실습 교육시 전압 파형 측정을 위하여 학생들이 직접 각 센서 및 엑츄에이터 커넥터에 탐침을 연결, 측정하고 있으며 이 과정에서 커넥터의 전선피복이 손상되는 사례가 빈번히 일어나고 있다. 본 논문에서는 트리즈의 6단계 창의성 기법을 적용하여 전선피복이 손상되는 원인을 찾아내고 혁신적인 해결책을 제시하였다.

• Journal of the Korean Magnetics Society
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• v.22 no.5
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• pp.178-182
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• 2012

This research suggested that the extraction of respiratory rate could be made possible by using frequency analysis in the data process for clip-type pulsimeter equipped with permanent magnet and Hall sensor. The pulse analysis included of cardiac motion information depending on variation of pulse waveforms is investigated by means of Fast Fourier Transformation (FFT). The peaks of FFT spectrums measured at 15, 20, 30, 40, and 50 tempos are coincided to each respiratory rate having 0.125 Hz, 0.16 Hz, 0.25 Hz, 0.33 Hz, and 0.41 Hz, respectively. The FFT spectrum using algorithm for the extraction of respiratory rate showed the best pulse waves measured during 300 s. Based upon these results, the clip-type pulsimeter could extract the effective respiratory rate reflecting physical effects.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05c
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• pp.242-246
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• 2002

인체의 손가락 끝에서 발생하는 맥의 파형과 온도, 피부저항을 측정할 수 있는 복합센서를 설계 제작하였다. 인체신호를 계측하는 여러 가지 방법 중에서 손가락 끝의 맥 파형을 계측하고자 광센서를 활용하여 계측시스템을 구현하였고 특성을 평가하였다. 그 결과 체온측정은 대략 $0.01^{\circ}C$의 분해능을 구현 할 수 있었고, 피부저항 측정은 최대 $5M{\Omega}$까지 측정 가능하고 최소분동은 $5k{\Omega}$ 정도이며, 맥박측정은 새롭게 포토센서를 적용하여 미소진동을 측정할 수 있었다.

• Journal of IKEEE
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• v.24 no.1
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• pp.67-71
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• 2020

In this study, a simulation model of the harmonic injection sensorless control technique is proposed. This model is suitable for the sensorless technique of low-speed area operation of motors. The motor of this model is permanent magnet motor. For sensorless control, 1kHz square wave is injected. The change in motor constant according to rotor position is realized by having different d-q inductance values. Sensorless techniques is implemented through functions of Simulink and models provided by Simulink libraries. It is shown that the harmonic component contained in the current is extracted using a filter, and the angle of the permanent magnet of the motor is detected using the extracted waveform. The validity of the simulation model is demonstrated through the estimated motor angle waveform and the related waveforms of the motor control applied to the 1kW permanent magnet motor.