표면적 변화에 기반한 입체적 웨어러블 호흡수 센서의 가능성 탐색

이승표,반현성,이주현 한국감성과학회 2018 감성과학 Vol.21 No.1

This study suggests the sensing method of the Three-dimensional respiration rate sensor based on surface area changes, and exploring the design direction of the three-dimensional breathing sensor and the design orientation of the garment. To achieve this, two types of three-dimensional respiration rate sensor were produced, and the study of the dummy and the subjects studied. The studyⅠ investigated the possibility of measurement of the threedimensional respiration sensor by the study variables of the sensor type and speed of respiration. The studyⅡ proposes a suitable type of sensor for each of the three measuring positions in addition to the study variables in the studyⅠ. To evaluate accuracy, reproducibility, and reliability of the three-dimensional respiration rate sensor, the BIOPAC was used to measure the respiration rate simultaneously with the three-dimensional respiration rate sensor. Through all these results of the experiment, it explored the possibility of measurement of the three-dimensional respiration sensor for the dummy. It also proposed a suitable type of sensor by measuring the respiration rate for the human body. 본 연구에서는 센서의 표면적 변화에 따른 입체적 호흡수 센서의 센싱 방식을 제안하고, 직물 기반의 입체적 호흡수센서의 성능 평가 및 의복에 적용할 수 있는 디자인 방향성을 탐색하고자 한다. 이를 위해 입체적 구조의 차이에따라 2가지 유형의 입체적 호흡수 센서를 제작하고 더미와 인체 대상으로 연구를 실시하였다. 연구Ⅰ은 더미 대상실험으로 센서의 유형 및 호흡 속도의 연구변인에 의해 입체적 호흡수 센서의 측정 가능성을 탐색하였다. 연구Ⅱ는7명의 20대 남성을 대상 실험으로 연구Ⅰ의 연구변인 이외에 3개의 측정 위치별 적합한 유형의 센서를 제안하였다. 입체적 호흡수 센서의 정확도, 재현성, 신뢰도를 평가하기 위해, 의료기기 분야의 대표적 웨어러블 호흡수 센서인 BIOPAC을 사용하여 입체적 호흡수 센서와 동시에 호흡수를 측정하였다. 이상의 연구 결과를 통해 더미 대상으로입체적 호흡수 센서의 측정 가능성을 탐색하였으며, 인체 대상으로 호흡수를 측정하여 측정 위치별 적합한 유형의 센서를 제안하였다.

힘센서를 이용한 기상 연료의 과도적 분사율 계측에 관한 연구

이재현,배규한,기영민,문석수 한국분무공학회 2022 한국액체미립화학회지 Vol.27 No.4

For carbon neutrality, direct-injection hydrogen engines are attracting attention as a future power source. It is essential to estimate the transient injection rate of hydrogen for the optimization of hydrogen injection in direct injection engines. However, conventional injection rate measurement techniques for liquid fuels based on the injection-induced fuel pressure change in a test section are difficult to be applied to gaseous fuels due to the compressibility of the gas and the sealing issue of the components. In this study, a momentum flux measurement technique is introduced to obtain the transient injection rate of gaseous fuels using a force sensor. The injection rate calculation models associated with the momentum flux measurement technique are presented first. Then, the volumetric injection rates are estimated based on the momentum flux data and the calculation models and compared with those measured by a volumetric flow rate meter. The results showed that the momentum flux measurement can detect the injection start and end timings and the transient and steady regimes of the fuel injection. However, the estimated volumetric injection rates showed a large difference from the measured injection rates. An alternative method is suggested that corrects the estimated injection rate results based on the measured mean volumetric flow rates.

지진가속도 계측 센서의 출력전압 선형비 검정기준 개선

조성철(Sung-cheoul Cho),김민준(Min-jun Kim),윤석원(Seok-won Yoon),원정훈(Jeong-hun Won) 한국방재학회 2023 한국방재학회논문집 Vol.23 No.3

In this study, the seismic acceleration sensor inspection standard, which estimates the error rate of the sensor’s output voltage to test its linear ratio, was analyzed and an improved standard was proposed. Seismic acceleration sensors should be sensitive to small angular changes under seismic excitation; however, the existing inspection standard only calculates the error rates at 3 0°, 45°, 60°, and 90° angles. Thus, we proposed an improved inspection standard that measures error ratios in 5° increments from 0° to 90°. Since the linear ratio is determined by estimating the error rate between theoretical and measured output voltages, the error rates in the X, Y, and Z directions were analyzed at changing angles. The results indicate that the error rate increased at small installation angles, and that the error rate decreased gradually at smaller angular increments. The current inspection standard underestimated the actual error rate, as it represented only 40~50% of the average error rate measured by the 5° interval measurements. Therefore, the current inspection standard for estimating the linear ratios of seismic acceleration sensors should be improved to reflect the influence of variations in the error rate according to the angular increment.

Development of a Six-Axis Force/Moment Sensor with Rectangular Taper Beams for an Intelligent Robot

Gab-Soon Kim 대한전기학회 2007 International Journal of Control, Automation, and Vol.5 No.4

This paper describes the development of a six-axis force/moment sensor with rectangular taper beams for an intelligent robot's wrist and ankle. In order to accurately push and pull an object with an intelligent robot's hand, and in order to safely walk with an intelligent robot's foot, the robot's wrist and ankle should measure three forces Fx, Fy, and Fz, and three moments Mx, My, and Mz simultaneously from the mounted six-axis force/moment sensor to the intelligent robot's wrist and ankle. Unfortunately, the developed six-axis force/moment sensor utilized in other industrial fields is not proper for an intelligent robot's wrist and ankle in the size and the rated output of the six-axis force/moment sensor. In this paper, the structure of a six-axis force/moment sensor with rectangular taper beams was newly modeled for an intelligent robot's wrist and ankle, and the sensing elements were designed by using the derived equations, following which the six-axis force/moment sensor was fabricated by attaching strain-gages on the sensing elements. Moreover, the characteristic test of the developed sensor was carried out by using the six-component force/moment sensor testing machine. The rated outputs from the derived equations agree well with those from the experiments. The interference error of the sensor is less than 2.87%.

다중센서 기반 차선정보 시공간 융합기법

이수목(Soomok Lee),박기광(Gikwang Park),서승우(Seung-woo Seo) 대한전자공학회 2015 전자공학회논문지 Vol.52 No.12

다리 환자를 위한 보행보조로봇의 종아리 링크 3축 힘센서 개발

김한솔 ( Han-sol Kim ),김갑순 ( Gab-soon Kim ) 한국센서학회 2017 센서학회지 Vol.26 No.2

This paper describes the design and fabrication of a three-axis force sensor with parallel plate beams (PPSs) for measuring the calf force while a patient with a walking assist robot is walking. Current walking assist robots can`t measure the weight of the patient`s leg and the robot`s leg which required for robot control. So, the three-axis force sensor in the calf link is designed and manufactured, it is composed of a Fx force sensor, a Fy force sensor and a Fz force sensor. The three-axis force sensor was designed using by FEM(Finite Element Method), and fabricated using strain-gages. The characteristics experiment of the three-axis force sensor was carried out respectively. The test results indicated that the repeatability error and the non-linearity error of three-axis force sensor was less than 0.04% respectively. Therefore, the fabricated three-axis force sensor in the calf link can be used to measure the patient`s calf force in the walking assist robot.

상지재활로봇의 팔힘측정용 2축 힘센서 설계

김갑순 ( Gab Soon Kim ) 한국센서학회 2015 센서학회지 Vol.24 No.2

This paper describes the design of a two-axis force sensor with two step plate beams for measuring forces in an upper-limb rehabilitation robot. The two-axis force sensor is composed of a Fz force sensor and a Ty torque sensor. The Fz force sensor measures the force applied to a patient’s arm pushed by a rehabilitation robot and the force of patient``s arm. The Ty torque sensor measures the torque generated by a patient’s arm motion in an emergency. The structure of sensor is composed of a force transmitting block, two step plate beams and two fixture blocks. The two-axis force sensor was designed using FEM (Finite Element Method), and manufactured using strain-gages. The characteristics test of the two-axis force sensor was carried out. as a test results, the interference error of the two-axis force sensor was less than 1.24%, the repeatability error of each sensor was less than 0.03%, and the non-linearity was less than 0.02%.

A disposable microfluidic flow sensor with a reusable sensing substrate

Kim, Jinho,Cho, Hyungseok,Han, Song-I,Han, Arum,Han, Ki-Ho Elsevier 2019 Sensors and actuators. B, Chemical Vol.288 No.-

<P><B>Abstract</B></P> <P>In many biological, medical and pharmaceutical applications, disposable flow sensors are highly desired to prevent biological contamination. However, due to their high cost, conventional microfluidic flow sensors are difficult to be used as disposable. This paper introduces a disposable microfluidic flow sensor (disposable-μFSensor) consisting of a disposable microchannel superstrate and reusable sensing substrate, which can be assembled and disassembled simply by vacuum pressure. Because the disposable microchannel superstrate is fabricated easily and cheaply using a silicone-coated release polymer thin film, it can be replaced after a single use, while the sensing substrate can be reused continuously. Experimental results show that the sensitivity, reproducibility, response time, long-term stability, resolution, and accuracy of the disposable-μFSensor are comparable to those of commercial microfluidic flow sensors. One of the key advantages of the disposable-μFSensor is that the measurable flow rate range can be adjusted very broadly, from 10 to 650 μL/min, by simply replacing only the disposable microchannel that has different bypass channel design, without having to change the sensing substrate. To demonstrate the usefulness of the disposable-μFSensor for biological, medical and pharmaceutical applications, the developed sensor was used to control the flow rates of a droplet generator, with the generated droplets having variations in diameter and volume of less than 1.25% and 4%, respectively. In summary, we report that the disposable-μFSensor is reproducible and accurate for various applications at low cost as well as resistant to biological contamination, in contrast to conventional flow sensors.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A disposable microfluidic flow sensor for preventing biological contamination. </LI> <LI> Hybrid flow sensor using a disposable microchannel and a reusable sensing substrate. </LI> <LI> Disposable microchannel made of a PET thin film; simple fabrication and low cost. </LI> <LI> Performance comparable to that of commercial flow sensors. </LI> <LI> Adjustable full-scale flow rate by replacing disposable microchannel without changing substrate. </LI> </UL> </P>

차량용 레인센서에서 생성된 센서시그널을 이용한 강우량 측정

김영곤(Kim, Young Gon),이석호(Lee, Suk Ho),김병식(Kim, Byung Sik) 대한토목학회 2018 대한토목학회논문집 Vol.38 No.2

본 연구에서는 차량용 레인센서를 이용하여 고해상도의 강우관측을 위한 관계식을 개발하였다. 차량용 레인센서는 8개의 채널로 이루어져 있으며, 각 채널은 강우발생시 차량의 전면유리창에 내리는 우적량을 감지하여 센서시그널을 생성하는데, 강우량이 높을수록 센서시그널은 낮은 값으로 형성된다. 레인센서에서 생성되는 센서시그널의 이러한 특징을 이용하여 관계식을 개발하였다. 특정강우를 발생시키기 위하여 인공강우 발생장치를 제작하였으며, 인공강우발생장치에서 분사되는 강우량의 변화에 따른 센서시그널의 변화 값을 분석하였다. 이 중 민감도 분석을 통해 다양한 강우량을 잘 반영하는 최적의 센서 채널을 선정하였다. 선정된 채널을 이용하여 5분 단위 센서시그널를 생성하였고 생성된 5분 단위센서시그널의 대표 값을 평균, 25분위, 50분위, 75분위로 설정하여 관계식을 구축하였다. 구축된 관계식을 이용하여 실강우 데이터에 적용하여 강우량 값을 환산하였고, 환산된 강우량은 지상강우관측소에서 관측된 강우량 값과의 비교를 통해 관계식의 신뢰도를 검증하였다. 검증결과 데이터의 이상치가 발견되어 관계식의 신뢰도는 다소 떨어졌지만, 해당 잔차 범위의 실험 데이터가 부족한 것으로 판단되었다. 개발된 관계식을 실강우에 적용시켜 강우량 값을 환산한 하였고, 신뢰도 검증을 위해 동시간에 관측된 지상강우 관측 장비에서 생성된 강우량 값과 비교를 하였고 관측 결과 레인센서는 0.5mm 이하의 미세한 강우량까지 측정하였고 평균 관측 오차는 0.36mm로 나타났다. In this study, we developed a relational formula for observing high - resolution rainfall using vehicle rain sensor. The vehicle rain sensor consists of eight channels. Each channel generates a sensor signal by detecting the amount of rainfall on the windshield of the vehicle when rainfall occurs. The higher the rainfall, the lower the sensor signal is. Using these characteristics of the sensor signal generated by the rain sensor, we developed a relational expression. In order to generate specific rainfall, an artificial rainfall generator was constructed and the change of the sensor signal according to the variation of the rainfall amount in the artificial rainfall generator was analyzed. Among them, the optimal sensor channel which reflects various rainfall amounts through the sensitivity analysis was selected. The sensor signal was generated in 5 minutes using the selected channel and the representative values of the generated 5 - minute sensor signals were set as the average, 25th, 50th, and 75th quartiles. The calculated rainfall values were applied to the actual rainfall data using the constructed relational equation and the calculated rainfall amount was compared with the rainfall values observed at the rainfall station. Although the reliability of the relational expression was somewhat lower than that of the data of the verification result data, it was judged that the experimental data of the residual range was insufficient. The rainfall value was calculated by applying the developed relation to the actual rainfall, and compared with the rainfall value generated by the ground rainfall observation instrument observed at the same time to verify the reliability. As a result, the rain sensor showed a fine rainfall of less than 0.5 mm And the average observation error was 0.36mm.

Asynchronous Sensor Fusion using Multi-rate Kalman Filter

Young Seop Son(손영섭),Wonhee Kim(김원희),Seung-Hi Lee(이승희),Chung Choo Chung(정정주) 대한전기학회 2014 전기학회논문지 Vol.63 No.11

We propose a multi-rate sensor fusion of vision and radar using Kalman filter to solve problems of asynchronized and multi-rate sampling periods in object vehicle tracking. A model based prediction of object vehicles is performed with a decentralized multi-rate Kalman filter for each sensor (vision and radar sensors.) To obtain the improvement in the performance of position prediction, different weighting is applied to each sensor’s predicted object position from the multi-rate Kalman filter. The proposed method can provide estimated position of the object vehicles at every sampling time of ECU. The Mahalanobis distance is used to make correspondence among the measured and predicted objects. Through the experimental results, we validate that the post-processed fusion data give us improved tracking performance. The proposed method obtained two times improvement in the object tracking performance compared to single sensor method (camera or radar sensor) in the view point of roots mean square error.