• 대한공간정보학회지
• /
• 제22권3호
• /
• pp.57-69
• /
• 2014

우리나라의 인구밀도는 2013년 기준, $1km^2$당 505명으로 도시국가를 제외하면 세계에서 3번째로 매우 높으며, 도심인구집중현상이 뚜렷하게 나타나고 있다. 이러한 수요를 충족시키기 위한 건축물의 대형화와 복합화 그리고 지하철 및 지하공간과의 연계화 경향이 심화되고 있으며, 이와 같은 현상으로 국민생활의 안전과 복지 증진을 위해 실내공간정보 DB와 더불어 정확한 실내측위DB 구축이 매우 필요한 상황이다. 본 연구에서는 사당역과 인천국제공항을 대상으로 모바일디바이스를 활용하여 실내 AP원시데이터를 수집하고 이를 통해 수집된 성과의 확인 보완 분석과정을 거쳐 Wi-Fi AP 위치 DB 및 RadioMap DB를 구축하였다. 또한 구축된 DB의 측위 성능 평가를 위해 인천공항 A동 지상 3층에서 10개 사당역 A동 지하 1층에서 9개의 지점을 선정하여 추정위치를 산출하여 추정위치 대비 참위치와의 거리, 즉 측위오차를 활용해 평가실험을 실시하였다. 그 결과, 전체 지점에 대한 평균과 표준편차가 인천공항은 평균 17.81m, 표준편차 17.79m, 사당역은 평균 22.64m, 표준편차 23.74m의 결과값을 얻을 수 있었다. 여기서 사당역의 경우 실외로 통하는 출입구에 인접한 지점은 가시 AP의 개수가 다른 지점 대비 크게 부족하여 측위성능이 떨어지는 것으로 해당지점을 제외한 데이터들을 종합적으로 검토하여보았을 때 구축된 DB를 활용한 측위 시 사용자의 위치가 근접한 지점으로 매핑되고 있는 것을 확인할 수 있었다. 이는 구축된 DB가 해당 지역의 Wi-Fi AP 위치 및 전파패턴 정보를 올바르게 담고 있다는 것을 의미하며 이를 토대로 한 실내공간정보 서비스가 가능할 것으로 판단된다.

• Journal of Positioning, Navigation, and Timing
• /
• 제11권1호
• /
• pp.35-44
• /
• 2022

In this paper, a dual foot (DF)-PDR system is proposed for the fusion of integration (IA)-based PDR systems independently applied on both shoes. The horizontal positions of the two shoes estimated from each PDR system are fused based on a particle filter. The proposed method bounds the position error even if the walking time increases without an additional sensor. The distribution of particles is a non-Gaussian distribution to express the lateral error due to systematic drift. Assuming that the shoe position is the pedestrian position, the multi-modal position distribution can be fused into one using the Gaussian sum. The fused pedestrian position is used as a measurement of each particle filter so that the position error is corrected. As a result, experimental results show that position of pedestrians can be effectively estimated by using only the inertial sensors attached to both shoes.

• 제어로봇시스템학회논문지
• /
• 제20권12호
• /
• pp.1204-1208
• /
• 2014

As required performance of UAV (Unmanned Aerial Vehicle) becomes more complex and complicated, required positioning accuracy is becoming more and more higher. GPS is a reliable world wide positioning providing system. Therefore, UAV generally acquires position information from GPS. But when GPS is not available such as too weak signal or too less GPS satellites environments, UAV needs alternative positioning system such as network positioning system. RSSI (Received Signal Strength Indicator) based positioning, which is one method of network positioning technologies, determines its position using RSSI measurements containing distance information from AP (Access Point)s. In that method, a selected AP's configuration has strong and tight relationship with its positioning errors. In this paper, for, we additionally account AP's configuration information by adopting DOP (Dilution of Precision) into AP selection procedures and provide more accurate RSSI based positioning results.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2002년도 ICCAS
• /
• pp.37.1-37
• /
• 2002

Localization is one of the most important functions for the mobile robot navigating in the unstructured environment. Most of previous localization schemes estimate current position and pose of mobile robot by applying various localization algorithms with the information obtained from sensors which are set on the mobile robot, or by recognizing an artificial landmark attached on the wall, or objects of the environment as natural landmark in the indoor environment. Several drawbacks about them have been brought up. To compensate the drawbacks, a new localization method that estimates the global position of the mobile robot by using a camera set on ceiling in the corridor is proposed. This sch...

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2007년도 춘계학술대회 논문집
• /
• pp.1330-1335
• /
• 2007

The HVAC and the air duct is to make optimal indoor environment. By the HVAC position, method and the air duct construction, the important elements can affect on cooling performance, passengers' convenience, and energy efficiency. According to this, there are features, such as the indoor temperature distribution, cooling performance, velocity distribution from diffuser, tend to be come out variously. Also, comparing and analysing temperature distribution, cooling performance, air velocity, noise based on the real practical vehicle tests, it shows features in detail. Besides, it can lead to make design the system of HVAC & air duct effectively.

• 제어로봇시스템학회논문지
• /
• 제14권9호
• /
• pp.925-930
• /
• 2008

Many sensor network applications require that each node's sensor data stream be annotated with its physical location in some coordinate system. Equipping GPS on every sensor node is often expensive and does not work in indoor deployments. Recently, cricket-based localization system is often used for indoor localization system. It is very important to know the exact position of beacons in cricket-based localization system for identifying moving sensor node's position. In this paper, a new method, Mobile Listener Detect Algorithm (MLD) which can automatically calculate the unknown newly installed beacons is proposed. For the verification of the feasibility of the proposed scheme, we have conducted several experiments.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
• /
• pp.352-354
• /
• 2007

This paper presents a method to estimate the position of a mobile robot by using a gyro sensor and accelerometer sensors on it. Together with contact sensors we propose a mapmaking algorithm for an indoor environment where the robot moves. The direction of robot can be estimated through a gyro sensor and the distance is founded out by accelerometers. Then one can presume the position of robot. Using the direction and distance values vector-based mapmaking job can be performed. Tactile sensors help the robot recognize the boundary limit value of indoor environment and decide outer wall line of the map.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• 제13권2호
• /
• pp.133-139
• /
• 2013

This paper proposes a vision-based indoor localization method for autonomous vehicles. A single upward-facing digital camera was mounted on an autonomous vehicle and used as a vision sensor to identify artificial landmarks and any natural corner features. An interest point detector was used to find the natural features. Using an optical flow detection algorithm, information related to the direction and vehicle translation was defined. This information was used to track the vehicle movements. Random noise related to uneven light disrupted the calculation of the vehicle translation. Thus, to estimate the vehicle translation, a Kalman filter was used to calculate the vehicle position. These algorithms were tested on a vehicle in a real environment. The image processing method could recognize the landmarks precisely, while the Kalman filter algorithm could estimate the vehicle's position accurately. The experimental results confirmed that the proposed approaches can be implemented in practical situations.

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2016년도 추계학술발표대회
• /
• pp.697-698
• /
• 2016

In this paper, we propose a novel approach to improve the accuracy for multiple low-cost drones in indoor environment. When the drones are flying, we employ sensors for checking their position in real-time. If the drones move out of their correct positions, the corresponding instructions are sent immediately. In another thread, we calibrate direction of the drones by checking yaw value. The adjustment is repeated until the drones locate at right position and direction.

• 제어로봇시스템학회논문지
• /
• 제12권10호
• /
• pp.962-967
• /
• 2006

Indoor positioning is highlighted recently, and various kinds of indoor positioning systems are under developments. Since positioning systems have their own characteristics, proper positioning scheme should be chosen according to the required specifications. Positioning methods are classified into time-based and angle-based one. This paper presents the error analysis of time-based and angle-based location methods. Because measurements of these methods are nonlinear, linearizations are needed in both cases to estimate the user position. In the linearization, Gauss-Newton method is used in both cases. To analyze the position error, we investigate the error ellipse parameters that include eccentricity, rotation angle, and the size of ellipse. Simulation results show that the major axes of TOA and AOA method lie in different quadrants at most region of workspace, especially where the geometry is poor. When the TOA/AOA hybrid is employed, it is found that the error ellipse is reduced to the intersection of ellipses of TOA and AOA.