• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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• pp.105-110
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• 1999

This paper presents a local obstacle avoidance method for indoor mobile robots using Lane method and velocity Space Command approach. The method locates local obstacles using the information form multi-sensors, such that ultrasonic sensor array and laser scanning sensor. The method uses lane method to determine optimum collision-free heading direction of a robot. Also, it deals with the robot motion dynamics problem to reduce some vibration and guarantee fast movement as well. It yields translational and rotational velocities required to avoid the detected obstacles and to keep the robot heading direction toward goal location as close as possible. For experimental verification of the method, a mobile robot driven by two AC servo motors, equipped with 24 ultrasonic sensor array and laser scanning sensor navigates using the method through a corridor cluttered with obstacle.

• 조명전기설비학회논문지
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• 제28권4호
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• pp.16-20
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• 2014

To prevent any accident in electric power utilities, many researches for inspection and diagnosis deteriorations occurring by corona discharges have been continuously studying. Inspection and diagnosis of electric power utility is very important to prevent an accident. This paper studies a measurement of ultra-violet(UV) ray of corona discharges on polymer insulators using an UV sensor array with an optic lens. The detection of an UV signal begins at 60kV, which is about 37.5% of the breakdown voltage of the polymer insulator and the stronger the high voltage increased to the polymer insulator was. It can be determined that the polymer insulator mounted on a live part must be examined when the discharge risk exceeds approximately 40%. In conclusion, the status of power utilities can be checked using an UV sensor.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.454-459
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• 2006

There are two main streams for pattern classification technology One is the method using PCA (Principal Component Analysis) and the other is the method using Neural network. Both of them have merits and demerits. In general, using PCA is so simple while using neural network can improve algorithm continually. Algorithm using neural network needs so many calculations rendering very slow response. In this work, an attempt is made to develop algorithms adopting both PCA and neural network merits for simpler, but faster and smarter.

• 한국군사과학기술학회지
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• 제22권4호
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• pp.484-491
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• 2019

General Hyperspectral Image Sensor acquires an image of line form such as a thin rectangle shape because of using 1D array Push Broom or Whisk Broom scanning method. A special mechanism is required for a Hyperspectral Image Sensor to operate for nadir and slant range. To design the mechanism, the characteristics of the flight motion and the overlap rate between consecutive frames were analyzed. Also, system requirements were proposed through modeling and simulation.

• 한국항공우주학회지
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• 제33권10호
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• pp.93-97
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• 2005

본 논문은 과학기술위성2호 핵심우주기술시험용 탑재체인 고 정밀 디지털 태양센서의 개발에 관한 것이다. 고 정밀 디지털 태양센서는 국내 최초의 디지털 태양센서로서 CMOS image sensor를 이용한다. FDSS는 광학부, FPGA(Field Programable Gate Array)부 및 MCU(Micro controller unit)부로 구성되어있다. 본 논문에서는 구경(Aperture)의 설계와 관련된 광학부의 광학특성 분석에 중점을 두어 기술하고자 한다. 또한 CMOS image sensor(CIS) 화소 면에 투사되는 태양광의 광학적 특성도 분석한다.

• International Journal of Precision Engineering and Manufacturing
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• 제6권4호
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• pp.67-72
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• 2005

In a park or street, we can see many people jogging or walking with their dogs that are chasing their masters. In this study, a pet robot that imitates dog's behavior is developed. The task of robot is to chase a person who is recognized as the master. The physical structure and the sensor system are designed for the task and environment. A three-wheel type locomotion system is designed as the robot's physical structure which can follow a person who is jogging in outdoor environment like a park. A sensor system, which can detect relative position of the master to the robot in highly dynamic and hazardous worlds, is developed. This sensor system consists of a signal transmitter which is held by the master and ultrasonic sensor array which are mounted on the robot. The transmitter emits RF (radio frequency) and ultrasonic signals simultaneously. The ultrasonic sensor array detects the signals and calculates direction and distance between the robot and the transmitter. The developed RF-ultrasonic sensor is evaluated through experiments. A purely reactive behavior-based control architecture is used for the robot. The behavior control performance of the robot is assessed in outdoor and indoor tests.

• Smart Structures and Systems
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• 제9권6호
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• pp.535-547
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• 2012

Controlling the balance of motion in a context involving a biped robot navigating a rugged surface or a step is a difficult task. In the present study, a $3{\times}5$ flexible piezoelectric tactile sensor array is developed to provide a foot pressure map and zero moment point for a biped robot. We introduce an innovative concept involving structural electrodes on a piezoelectric film in order to improve the sensitivity. The tactile sensor consists of a polymer piezoelectric film, PVDF, between two patterned flexible print circuit substrates (FPC). Additionally, a silicon rubber bump-like structure is attached to the FPC and covered by a polydimethylsiloxane (PDMS) layer. Experimental results show that the output signal of the sensor exhibits a linear behavior within 0.2 N ~ 9 N, while its sensitivity is approximately 42 mV/N. According to the characteristic of the tactile sensor, the readout module is designed for an in-situ display of the pressure magnitudes and distribution within $3{\times}5$ taxels. Furthermore, the trajectory of the zero moment point (ZMP) can also be calculated by this program. Consequently, our tactile sensor module can provide the pressure map and ZMP information to the in-situ feedback to control the balance of moment for a biped robot.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.707-708
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• 2012

• Journal of information and communication convergence engineering
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• 제12권3호
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• pp.140-144
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• 2014

A general linearly constrained adaptive array is examined in the weight vector space to illustrate the array performance with respect to the gain factor. A narrowband linear adaptive array is implemented in a coherent signal environment. It is shown that the gain factor in the general linearly constrained adaptive array has an effect on the linear constraint gain of the conventional linearly constrained adaptive array. It is observed that a variation of the gain factor of the general linearly constrained adaptive array results in a variation of the distance between the constraint plane and the origin in the translated weight vector space. Simulation results are shown to demonstrate the effect of the gain factor on the nulling performance.

• 항공우주기술
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• 제13권1호
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• pp.27-36
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• 2014

인공위성은 예측 가능한 데이터를 이용하여 자신의 상태를 스스로 파악하며, 자연적으로 발생할 수 있는 일시적인 문제가 아니거나 오류가 전이되어 더 큰 문제를 발생시킬 수 있다고 판단될 경우를 대비하여 지상국과의 접속이 없는 상태에서도 스스로 고장 관리를 수행할 수 있도록 설계되어 있다. 태양 센서를 이용한 정상상태에서의 자세 오류 감지도 이러한 고장관리 항목 중의 하나로 사용될 수 있다. 본 연구에서는 회전하는 태양전지판에 장착되어 있는 태양 센서 데이터를 이용한 오류 감지 방법을 제안하였다. 태양전지판의 운용 방법에 따라 정상적인 상태에서 발생할 수 있는 태양 센서의 오차를 예측하고 이 예측된 값으로부터 벗어나는 정도를 파악하여 오류를 감지하도록 하였다. 또한, 식구간 존재 시에는 태양센서가 그 출력을 내지 못하므로 오류 감지에 문제가 없도록 보정하였다. 마지막으로 궤도 상 데이터를 이용하여 제안된 방법의 타당성을 검증하였다.