• Proceedings of the KIEE Conference
• /
• 2004.07d
• /
• pp.2426-2428
• /
• 2004

자율이동로봇에 있어서 기본적이면서도 가장 중요한 문제 중의 하나는 자신의 위치를 추정하는 것이다. 만약 로봇 자신이 어디에 있는지 알지 못한다면 효과적으로 로봇의 동작을 계획할 수도 없을 뿐 아니라, 목표물을 찾을 수도 없으며 목표에 도달하는 데 있어서도 상당한 문제가 생기게 된다. 이미 로봇의 자기 위치추정 문제에 대해서는 GPS, 시각, 레이져, 초음파 센서등을 이용한 많은 기술들이 개발된 상태이다. 하지만 각각의 방법들에 있어서 정확성의 향상은 하드웨어 비용의 증가와 추가 전력을 고려해야 하는 등의 문제를 가져오게 되었다. 문제의 핵심은 저렴하면서도 손쉽고 정확한 값을 갖는 알고리즘을 개발하는 데 있다고 할 수 있는 것이다. 본 논문에서는 초음파 센서를 이용하여 이러한 문제에 대한 만족할 만한 답을 얻고자 한다.

• Proceedings of the IEEK Conference
• /
• 2009.05a
• /
• pp.187-189
• /
• 2009

Position estimation in indoor is significant problem, because GPS which is usually used for outdoor positioning cannot be utilized to indoor positioning. Sensor network can be a solution for the positioning. Recently, chirp spread spectrum(CSS) specified in IEEE 802.15.4a provides an ability of ranging. Based on the results of the ranging, a position of a CSS node can be calculated by using trilateration. In this case, Kalman filter can be applied to the trilateration because of the measurement noise. In this paper, we apply the unscented Kalman filter for the trilateration. The trilateration can be represented to a nonlinear state space equation, and the unscented Kalman filter is suitable for nonlinear state space equation. Through the experimental results. we show the accuracy of the estimated position.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.312-315
• /
• 2003

The paper presents a small. unmanned remote controlled probing ship that can reduce the cost for acquiring data of marine and coastal environments. The control system is composed of three microprocessors. one is for overall mission control. another for control of propulsion motors. and the other for sensor operation. For communication system, we adopt direct and indirect methods based on the wireless modem of commercial cellular telephone. The former is a direct communication between the modems of the ship and the server. and the latter is an indirect communication via internet between the ship and the server. The system is equipped with a digital compass and a GPS system for position estimation, and extended Kalman filter is used for the data association. The performance of the ship is demonstrated with the results produced by sets of experiments.

• Proceedings of the KSRS Conference
• /
• 2008.10a
• /
• pp.37-40
• /
• 2008

The purpose of this paper is to extract DEMs from Spot-3 strips using orbit modeling technique. Spot-3 stereo strip images along 420km in distance were used for experiments. The orbit modeling technique has been suggested to establish accurate geometric models for a whole strip taken on the same orbit using only a small number of GCPs on the top area of the strip. This method enables extraction of orientation parameters of the scene along the strip that is needed to generate DEMs. Consequently, we were able to extract DEMs over the areas without accurate GCPs obtained by GPS surveying per each scene. Assessment of accuracy was carried out using USGS DTED. DEMs generated from the orbit modelling technique suggested showed satisfactory performance when quantitative analysis of accuracy assessment was carried out.

• Journal of Advanced Navigation Technology
• /
• v.11 no.2
• /
• pp.146-153
• /
• 2007

Autonomous unmanned vehicle is able to find the path and the way point by itself. For the more precise navigation performance, Extended kalman filter, which is integrated with inertial navigation system and global positioning system is proposed in this paper. Extended kalman filter's performance is evaluated by the simulation and applied to the unmanned vehicle. The test result shows the effectiveness of extended kalman filter for the navigation.

• The Journal of Korea Robotics Society
• /
• v.6 no.2
• /
• pp.182-188
• /
• 2011

This paper describes a method of road tracking by using a vision and laser with extracting road boundary (road lane and curb) for navigation of intelligent transport robot in structured road environments. Road boundary information plays a major role in developing such intelligent robot. For global navigation, we use a global positioning system achieved by means of a global planner and local navigation accomplished with recognizing road lane and curb which is road boundary on the road and estimating the location of lane and curb from the current robot with EKF(Extended Kalman Filter) algorithm in the road assumed that it has prior information. The complete system has been tested on the electronic vehicles which is equipped with cameras, lasers, GPS. Experimental results are presented to demonstrate the effectiveness of the combined laser and vision system by our approach for detecting the curb of road and lane boundary detection.

• 제어로봇시스템학회:학술대회논문집
• /
• 2000.10a
• /
• pp.439-439
• /
• 2000

In this paper, the relationship among the vertical acceleration, measuring points and walking patterns is analyzed. To measure acceleration, the acceleration measurement unit and communication board is constructed. It uses MEMS accelerometer ADXL-202 that detects 2-axis acceleration simultaneously. It is shown by the experiment test that the walking pattern is recognized and walking step is detected at easy when acceleration measurement unit is mounted on leg.. This results can be directly utilized in designing the personal navigation system with low-cost inertial sensor.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2010.04a
• /
• pp.77-80
• /
• 2010

The demand for human security significantly promotes the development of surveillance applications using a multi-sensor integrated UAV system. For more sophisticated operations, the system should provide a sequence of images rectified in a ground coordinate system in realtime. This rectification requires accurate position and attitude of the camera at the time of exposure of each image, which can be estimated through an Aerial Triangulation process using the GPS/INS data and tie points between adjacent images. In this work, the KLT tracker is utilized to obtain the tie points. To satisfy the realtime requirements, we present an approach to speed up the tracker by supplying the initial guessed positions of tie points based on the exterior orientation. The experimental results show that, when the guessed positions are supplied, the KLT tracker consumed less computational time than the ordinary KLT which is more suitable to be incorporated into the realtime image georeferencing process.

• Proceedings of the Korean Information Science Society Conference
• /
• 2006.10d
• /
• pp.330-333
• /
• 2006

사용자의 위치 기반 서비스는 유비쿼터스 컴퓨팅 환경에서 중요한 역할을 하고 있다. 위치 기반 서비스는 현재 사용자나 사물의 위치를 표시 해 주는 서비스이다. 이러한 위치 인식 기반 서비스는 GPS, ActiveBadge, Sensor 등과 같은 장비를 이용하여 위치를 인식 할 수 있다. 그러나 특허나 벤더에 따라 서로 다른 기술들을 사용하기 때문에 매우 노동 집약적이며 각 장비마다 가격이 고가이기 때문에 의미 있는 ROI를 이끌어 낼 수 없다. 비록 가격이 낮아져 의미 있는 ROI를 이끌어 내더라도 대부분의 위치 인식은 Zone-level정도의 정확도를 가지고 있다. 본 논문에서는 이러한 문제점을 해결하기 위해 최근 급속히 보급되고 있는 IEEE 802.11 Wireless LAN 인프라를 활용하여 AP의 RSSI 정보를 이용하여 위치 인식을 한다. 또한, Zone-level에서 room-level로 기존의 위치 인식보다 좀 더 정밀하게 하기 위하여 삼각측량 알고리즘을 이용하여 설계하였다.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.18 no.4
• /
• pp.115-120
• /
• 2010

The reduction rate of fuel consumption by showing the fuel injection data for driver was measured in this study. The fuel injection data are composed of injection period, real time fuel economy and average fuel economy. The fuel consumption was measured by processing the voltage signal of injector and driven distance by GPS sensor. The fuel consumption was reduced by driving more carefully, i.e driving more steady without sudden acceleration and deceleration watching these fuel injection data. The reduction rate was up to 37% and the rate increased as the driver is customed to this driving pattern.