• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 A
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• pp.175-178
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• 2003

This paper describes a active audition system for robot-human interface in real environment. We propose a strategy for a robust sound localization and for -talking speech recognition(60-300cm) based on 2-dimensional microphone array. We consider spatial features, the relation of position and interaural time differences, and realize speaker tracking system using fuzzy inference profess based on inference rules generated by its spatial features.

• 전기학회논문지
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• 제59권1호
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• pp.197-203
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• 2010

The problem of location awareness in wireless sensor networks where nodes use GPS (Global Positioning System), remains challenging problem, when considering the required large energy consumption during the localization phase. In this paper we designed hardware for GPS based localization and propose a framework, called ELS, to consume low cost energy. In the ELS framework, sensor nodes are equipped with GPS. Because GPS spends large energy for position awareness, conventional localization algorithms cannot use GPS-device. We try to find a solution for efficient energy expenditure of GPS. Finally, we derive optimal transmission power of GPS data and a scheme of localization through experiment and simulation.

• 시스템엔지니어링학술지
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• 제16권1호
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• pp.78-83
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• 2020

Recently, the use of domestic products securing domestic technology is encouraged, because of export restrictions of the countries or DMSMS(diminishing manufacturing sources and shortages). Domestic weapon systems are actively focused on the parts localization process of R&D projects based on Systems Engineering. However, it is the only way to do technical review for Systems Engineering process up to now. There is a case of application in Localization with Systems Engineering process, but the SE activity is not enough. This study is how to apply Systems Engineering process to Localization effectively based on real cases.

• 로봇학회논문지
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• 제7권4호
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• pp.276-283
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• 2012

Due to the low localization accuracy and the requirement of special infrastructure, current LBS(Localization Based Service) is limited to show P.O.I.(Point of Interest) nearby. Improvement of IMU(Inertial Measurement Unit) based deadreckoning is presented in this paper. Additional sensors such as the magnetic compass and magnetic flux sensors are used as well as the accelerometer and the gyro for getting more information of movement. Based on the pedestrian movement, appropriate sensor information is selected and the complementary filter is used in order to enhance the accuracy of the localization.

• Journal of information and communication convergence engineering
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• 제9권2호
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• pp.155-160
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• 2011

In distributed source localization where sensors transmit measurements to a fusion node, we address the sensor selection problem where the goal is to find the best set of sensors that maximizes localization accuracy when quantization of sensor measurements is taken into account. Since sensor selection depends heavily upon rate assigned to each sensor, joint optimization of rate allocation and sensor selection is required to achieve the best solution. We show that this task could be accomplished by solving the problem of allocating rates to each sensor so as to minimize the error in estimating the position of a source. Then we solve this rate allocation problem by using the generalized BFOS algorithm. Our experiments demonstrate that the best set of sensors obtained from the proposed sensor selection algorithm leads to significant improvements in localization performance with respect to the set of sensors determined from a sensor selection process based on unquantized measurements.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2301-2306
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• 2005

Even if there are lots of researches on localization using 2D range finder in static environment, very few researches have been reported for robust real-time localization of mobile robot in uncertain and dynamic environment. In this paper, we present a new localization method based on ICP(Iterative Closest Point) algorithm for navigation of mobile robot under dynamic or uncertain environment. The ICP method is widely used for geometric alignment of three-dimensional models when an initial estimate of the relative pose is known. We use the method to align global map with 2D scanned data from range finder. The proposed algorithm accelerates the processing time by uniformly sampling the line fitted data from world map of mobile robot. A data filtering method is also used for threshold of occluded data from the range finder sensor. The effectiveness of the proposed method has been demonstrated through computer simulation and experiment in an office environment.

• 항공우주기술
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• 제10권2호
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• pp.11-19
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• 2011

스마트무인기 로터 블레이드의 국산화 개발이 수행되었다. 국산화 개발은 원소재와 물성치가 가장 유사한 국내 생산 복합소재의 선정, 새로운 소재의 물성치 데이터 구축을 위한 쿠폰시험, 블레이드 단면 물성치의 재계산, 공진, 정적/피로 강도, 공탄성 안정성의 구조동역학 설계요구조건에 대한 검증 등을 포함하며, 그 결과에 대하여 기술하였다. 또한 본 논문에서는 스마트무인기 국산화 블레이드 개발과정에서 개선된 공정에 대하여 간략히 기술하였다.

• 인터넷정보학회논문지
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• 제11권1호
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• pp.27-33
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• 2010

본 논문은 실내 위치 인식을 위하여 ZigBee 이동 장치의 위치를 측정하였으며 Bayesian Markov 위치 추론 기법을 적용하였다. 정확도 분석을 위해 기존의 지도 기반의 위치 인식 기법과 비교하였는데 이 기법은 이미 지정된 위치에서의 RSSI 데이터를 데이터베이스화하여 참조하도록 하는 반면 Bayesian Markov 추론 방법은 시간, 방향, 거리의 변화에 영향을 받았다. 이 두가지 방법에 따른 측정은 지그비 모듈을 사용하여 RSSI를 측정한 결과를 토대로 이루어졌으며 그 결과 실내에서의 RSSI와 거리와의 관계로 접근하는 것이 바람직하며 Bayesian Markov에 의한 분석결과 기존의 지도 기반 위치 인식 기법에 비하여 높은 정확도를 보여주었다. 결과적으로 기존의 지도 기반 위치 인식 기법은 사전에 환경 요인에 대한 설정을 해주어야 하고, 보다 낮은 정확도를 가지고 있으므로 환경 변화가 잦은 실내에서는 부적합하다고 생각된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1934-1935
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• 2011

In order for a service robot to perform several tasks, basically autonomous navigation technique such as localization, mapping, and path planning is required. The localization (estimation robot's pose) is fundamental ability for service robot to navigate autonomously. In this paper, we propose a new system for point pattern matching based visual global localization using spot lightings in ceiling. The proposed algorithm us suitable for system that demands high accuracy and fast update rate such a guide robot in the exhibition. A single camera looking upward direction (called ceiling vision system) is mounted on the head of the mobile robot and image features such as lightings are detected and tracked through the image sequence. For detecting more spot lightings, we choose wide FOV lens, and inevitably there is serious image distortion. But by applying correction calculation only for the position of spot lightings not whole image pixels, we can decrease the processing time. And then using point pattern matching and least square estimation, finally we can get the precise position and orientation of the mobile robot. Experimental results demonstrate the accuracy and update rate of the proposed algorithm in real environments.

• 로봇학회논문지
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• 제15권4호
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• pp.357-364
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• 2020

Indoor localization using an artificial marker plays a key role for a robot to be used in a service environment. A number of researchers have predefined the positions of markers and attached them to the positions in order to reduce the error of the localization method. However, it is practically impossible to attach a marker to the predetermined position accurately. In order to visualize the position of an object in the environment based on the marker attached to them, it is necessary to consider a change of marker's position or the addition of a marker because of moving the existed object or adding a new object. In this paper, we studied the method to estimate the artificial marker's global position for the visualization of environment. The system calculates the relative distance from a reference marker to others repeatedly to estimate the marker's position. When the marker's position is changed or new markers are added, our system can recognize the changed situation of the markers. To verify the proposed system, we attached 12 markers at regular intervals on the ceiling and compared the estimation result of the proposed method and the actual distance. In addition, we compared the estimation result when changing the position of an existing marker or adding a new marker.