• 전자공학회논문지
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• 제49권9호
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• pp.335-343
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• 2012

본 논문은 근거리에서 접근하는 표적에 대한 레이더와 열영상의 관측데이터를 기반으로 정보융합을 수행하여 표적을 추적하는 알고리즘을 기술하고 있다. 일반적으로 칼만필터를 이용한 추적 융합 방법은 동기화된 레이더 및 열영상의 데이터를 근간으로 하고 있으며, 비동기적으로 동작하는 실제 시스템에 적용하기에는 많은 제한사항을 가지고 있다. 제안된 알고리즘에서의 중점사항은 동기화되어 있지 않은 서로 다른 두 센서인 레이더와 열영상의 관측데이터가 입력되었을 때 레이더의 거리정보와 추적상태벡터를 이용하여 관측값의 시간차이를 보상하여 관측치 융합 후 추적을 수행하는 것이다. 제안된 알고리즘의 성능평가를 위해 기존의 궤적기반 정보융합방법 및 측정치 융합기법과 성능을 비교하여 제시한다.

• 제어로봇시스템학회논문지
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• 제16권12호
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• pp.1159-1166
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• 2010

Today, detecting the location of moving object has been traced as various methods in our world. In this paper, we preset the system to improve the estimation accuracy utilizing detail localization using radar sensor based on WSN and situational awareness for a calibration (context aware) database, Rail concept. A variety of existing location tracking method has a problem with receiving of data and accuracy as tracking methodology, and since these located data are the only data to be collected for location tracing, the context aware or monitering as the surrounding environment is limited. So, in this paper, we enhanced the distance aware accuracy using radar sensor utilizing the Doppler effect among the distance measuring method, estimated the location using the Triangulation algorithm. Also, since we composed the environment data(temperature, illuminancem, humidity, noise) to entry of the database, it can be utilized in location-based service according to the later action information inference and positive context decision. In order to verify the validity of the suggested method, we give a few random situation and built test bed of designed node, and over the various test we proved the utilizing the context information through route tracking of moving and data processing.

• 한국멀티미디어학회논문지
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• 제21권3호
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• pp.382-390
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• 2018

A major accident occurring on the bed is falls that occur during at times when the care of nurses or protectors is inadequate, which is fatal to patients or the elderly. In particular, Enuresis or sleepiness caused by sleep apnea increases the risk of falls. Therefore, it is very important to detect falls and sleep apnea of patients without infringing privacy in the bed to patient's safety and accident prevention. In this paper, we reviewed the technologies developed for bed monitoring and implemented a non-intrusive monitoring system. The Occupancy Sensor allows the temperature of the bed and surrounding area to be extracted to enable track of the patient's motion. The Doppler Radar detects the patient's movements at normal times and the respiration state when patients have no movement during sleeping. It is specially designed for real-time monitoring of falling and respiration during sleeping through contactless multi-sensing while solving patient's privacy problems.

• 한국산학기술학회논문지
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• 제10권7호
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• pp.1532-1535
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• 2009

본 논문은 절전형 센서에 사용되는 24GHz대역의 CW 레이더 송수신기의 설계에 관한 것이다. K-대역의 송수신기 회로의 기본 구조와 전력분배기와 송수신 안테나가 디자인 되었고 발진기, 주파수혼합기, 고주파 증폭기는 상용 제품을 사용하였다. 제작된 분배기와 안테나의 성능이 측정되었고 송신 주파수와 출력전력레벨이 상용 제품에 적용될 수 있을 정도로 양호하였다. 제안된 송수신기의 크기는 35${\times}$35${\times}$10(mm)이며 여러 가지 제품에 사용될 수 있도록 설계되었다.

• 한국초전도ㆍ저온공학회논문지
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• 제24권1호
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• pp.29-33
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• 2022

Recently, development of a cryogenic fluids storage tank for storing or transporting liquid hydrogen is actively in progress. In cryogenic fluids storage tanks, hydrogen evaporates due to the extreme temperature difference inside and outside the tank. As the mass of the cryogenic fluids changes with continuous vaporization, the fluids level also changes. Therefore, there is need for a method of accurately measuring the level change in the storage tank. In the case of general cryogenic fluids, it is difficult to accurately measure the level because the dielectric constant is very low. As a method of measuring cryogenic fluids level with low dielectric constant, it can be used an Millimeter wave (MM wave) FMCW radar sensor. However, the signal sensitivity is very weak and the level accuracy is poor. In this paper, the signal sensitivity is improved by designing the horn lens antenna of the existing 80 GHz FMCW radar sensor. Horn lens antenna is fabricated by FDM/SLA type 3D printer according to horn and lens characteristics. The horn is used to increase the signal gain and the lens improves the signal straightness. This makes it possible to measure the level of cryogenic fluids with a low dielectric constant.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권4호
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• pp.1209-1223
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• 2022

Blood pressure is one of the key physiological parameters for determining human health, and can prove whether human cardiovascular function is healthy or not. In general, what we call blood pressure refers to arterial blood pressure. Blood pressure fluctuates greatly and, due to the influence of various factors, even varies with each heartbeat. Therefore, achievement of continuous blood pressure measurement is particularly important for more accurate diagnosis. It is difficult to achieve long-term continuous blood pressure monitoring with traditional measurement methods due to the continuous wear of measuring instruments. On the other hand, radar technology is not easily affected by environmental factors and is capable of strong penetration. In this study, by using machine learning, tried to develop a linear blood pressure prediction model using data from a public database. The radar sensor evaluates the measured object, obtains the pulse waveform data, calculates the pulse transmission time, and obtains the blood pressure data through linear model regression analysis. Confirm its availability to facilitate follow-up research, such as integrating other sensors, collecting temperature, heartbeat, respiratory pulse and other data, and seeking medical treatment in time in case of abnormalities.

• Smart Structures and Systems
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• 제16권3호
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• pp.521-535
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• 2015

Vibration-based monitoring is one approach used to perform structural condition assessment. By measuring structural response, such as displacement, dynamic characteristics of a structure may be estimated. Often, the primary dynamic responses in civil structures are below 5 Hz, making accurate low frequency measurement critical for successful dynamic characterization. In addition, static deflection measurements are useful for structural capacity and load rating assessments. This paper presents a DC coupled continuous wave radar to accurately detect both dynamic and static displacement. This low-cost radar sensor provides displacement measurements within a compact, wireless unit appropriate for a range of structural monitoring applications. The hardware components and operating mechanism of the radar are introduced and a series of laboratory experiments are presented to assess the performance characteristics of the radar. The laboratory and field experiments investigate the effect of factors such as target distance, motion amplitude, and motion frequency on the radar's measurement accuracy. The results demonstrate that the radar is capable of both static and dynamic displacement measurements with sub-millimeter accuracy, making it a promising technology for structural health monitoring.

• 인터넷정보학회논문지
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• 제25권2호
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• pp.21-28
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• 2024

레이다는 자율주행 차에 있어 필수적인 센서 부품으로, 레이다가 활용되는 시장은 점차 커지고 있으며 제품 종류도 다양해지고 있다. 본 연구에서는 평가 공정에서부터 레이다의 불량 여부를 예측해 자율주행의 안정성과 효율성을 높일 수 있도록 성능 예측 모델을 구축하고 평가하였다. 레이더 공정 과정의 39607개 입력 데이터로 모델을 학습하였으며, 결과적으로 17개 모델을 스태킹 앙상블했을 때 Meta Ridge 모델이 가장 높은 학습률을 나타내는 것을 확인하였다. 이러한 연구 결과가 제품의 불량을 공정 단계에서 우선 예측해 수율을 극대화하고 불량으로 인한 제품 폐기 비용을 감축하는 데 도움이 될 것으로 기대 한다.

• 센서학회지
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• 제26권6호
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• pp.386-390
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• 2017

A $5^{th}$-order low-pass filter (LPF) chip implemented in a six-layer low-temperature co-fired ceramic (LTCC) dielectric substrate has been presented. Lumped elements constituting the LPF are designed three-dimensionally in multilayers. In order to improve the parasitic and mutual coupling effects between them, the LPF is designed by sequentially integrating the three-dimensional (3D) lumped elements, by comparing it to the results of the schematic circuit and 3D electromagnetic (EM) analysis. The designed 3D LPF chip was fabricated in a six-layer LTCC substrate as small as $4.0{\times}3.22{\times}0.68mm^3$. The measured return and insertion losses are less than -11 dB and -0.61 dB, respectively, below 1.5 GHz.

• 한국자동차공학회논문집
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• 제9권2호
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• pp.137-142
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• 2001

A throttle/brake control law for the intelligent cruise control(ICC) systems has been proposed in this paper. The ICC system consists of a vehicle detection sensor, the control algorithm and a throttle/brake actuators. The control performance has been investigated through vehicle tests. The test vehicle is equipped with a MMW radar sensor, a solenoid-valve-controlled Electronic-Vacuum-Booster(EVB) and a step-motor controlled throttle actuator. The results indicate the proposed throttle/brake control laws can provide satisfactory vehicle-to-vehicle distance and velocity control performance.