• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.7
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• pp.1520-1525
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• 2009

In this paper, we study and simulate the suggested position control system using GPS and USN to replace the existing control system of a crane. For the correct approach, the position control system of a crane is divided into the control system of the ground station and the mobile station The hardware is comprised of GPS receiving module to receive the position control data of a crane from GPS satellites, bluetooth communication module for the data communication between the ground station and the mobile station, supersonic sensor module for a precise position control of a crane, motor to replace a crane roller, embedded MCU(ATmega128L) and so on. In here, an embedded MCU controls GPS receiving module, bluetooth communication module and supersonic sensor module. The Software is comprised of three programs. Three programs are the program to filter GGA output part in a receiving data of GPS receiving module, the driving program for supersonic sensor module, the digital map program to monitor a crane location. From the simulation results, it is demonstrated that the proposed system has the capability of crane position control with 1cm precision.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.8
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• pp.918-931
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• 2013

The conventional object tracking techniques using PTZ camera detects object movements by analyzing acquired image. However, this technique requires expensive hardware devices to perform a complex image processing. And it is occasionally hard to detect object movements, if an acquired image is low quality or image acquisition is impossible. In this paper, we proposes a smart security CCTV system applying to wireless sensor network technique based on IEEE 802.15.4 standard to overcome the problems of conventional object tracking technique, which enables to track suspicious objects by detecting object movements and GPS data in sensor node. This system enables an efficient control of PTZ camera to observe a wide area, decreasing image processing complexity. Also, wireless sensor network is implemented using mesh networks to increase the efficiency of installing sensor node.

• Journal of the Korea Society of Computer and Information
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• v.16 no.3
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• pp.167-174
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• 2011

This paper proposed a smart-phone based user movement state identification algorithm. Then movement state of the user is identified by calculating the location and moving speed using the GPS sensor, and detailed movement methods are identified by analyzing the data from the Orientation sensor. In this study, two sensors of the smart-phone were used to implement the user movement status identification algorithm and to perform tests. The reference values of the speed and orientation required for the identification of the movement type were defined based on the experimental data. The results of this study showed that the movement type of a smart-phone user can be identified using the user movement state identification algorithm.

• Spatial Information Research
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• v.21 no.6
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• pp.57-67
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• 2013

GPS based car navigation systems show significant problems in such environment as a tunnel, a road surrounded by high buildings. In this study, we thus propose a method to determine positions and attitudes using only in-vehicle sensory data without a GPS. To check the feasibility of this method, we constructed a system to acquire in-vehicle sensory data and reference data simultaneously. We acquired test data using this system, estimated the trajectory based on the proposed method and evaluated the accuracy of both the sensory data and the trajectory. The speed and angular velocities provided by the in-vehicle sensors include 1.1 km/h and 0.8 deg/s RMS errors, respectively. The estimated trajectory using these data shows 20.8 m RMS errors for a 15 minute drive. In future, if we further combine additional sensors such as a camera and a GPS, we can achieve a high accurate navigation system at a low cost without an expensive high-grade external IMU.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.1
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• pp.65-72
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• 2010

In this study, the performances of a medium grade IMU which is aimed for Mobile Mapping System and a low grade IMU for pedestrian navigation are analyzed through simulations under GPS signal blockage. In addition, an analysis on the accuracy improvement of barometer, electronic compass, or multi-sensor(combination of barometer and electronic compass) to correct medium grade or low grade IMU errors in the situation of GPS signal blockage is performed. With the medium grade IMU, the three dimensional positioning error from INS exceeds the demanded accuracy of 5m when the block time is over 30 seconds. When we correct IMU with barometer, compass, or multi-sensor, however, the demanded accuracy is maintained up to 60 seconds. In addition, barometer is more effective than the electronic compass when they are combined. In case of low grade IMU like MEMS IMU, the three dimensional positioning error from INS exceeds the demanded accuracy of 20m when the block time is over 15 seconds. When we correct INS with barometer, compass, or multi-sensor, however, the demanded accuracy is maintained up to 15 seconds in simulation results. On the contrary to medium grade IMU, electronic compass is more effective than the barometer in case of low velocity such as pedestrian navigation. It is expected that the analysis suggested a method to decrease position or attitude error using aided sensor integration when MMS or pedestrian navigation is operated under 1he environment of GPS signal blockage.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3153-3158
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• 2014

Children in schoolzone accidents occur frequently in order to actively respond to the situation on the module for automated recognition research. By the vehicle penetration such like schoolzone, child object recognition, and GPS coordination information, the monitoring scenario can be constructed, and if an event occurs corresponding to strategic scenario so that suitable reaction can be provided to increase safety level to the schoolzone. In this paper, a GPS sensor and the image sensor and the monitoring server on the network based on the integration of context-aware methods have been studied. The image sensor section and the GPS section through analysis of the situation analysis and recognition of the object based on the scenario can actively cope with the situation according to the methods proposed.

• Journal of Advanced Navigation Technology
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• v.21 no.3
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• pp.251-257
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• 2017

Recently, hybrid positioning system combining GPS, vision sensor, and inertial sensor has drawn many attentions to estimate accurate vehicle positions. Since accurate multi-sensor fusion requires efficient time synchronization, this paper proposes an efficient method to obtain time synchronized measurements of vision sensor, inertial sensor, and OBD device based on GPS time information. In the proposed method, the time and position information is obtained by the GPS receiver, the attitude information is obtained by the inertial sensor, and the speed information is obtained by the OBD device. The obtained time, position, speed, and attitude information is converted to the color information. The color information is inserted to several corner pixels of the corresponding image frame. An experiment was performed with real measurements to evaluate the feasibility of the proposed method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.3
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• pp.528-533
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• 2005

The purpose of the study is to develop ship's bearing sensor using GPS receiver which can play a role as a ship's secondary compass. In this research, two GPS receivers are used to determine the bearing in real time. Then we investigated the bearing accuracy associated with the error pattern of two GPS receivers. Especially, the results are as follows the investigation on the system design of GPS-Compass, the modeling to compute heading of sailing, the analysis on bearing accuracy with the error pattern, the defining possibility to play a role as a ship's secondary compass.

• Journal of Sensor Science and Technology
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• v.18 no.1
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• pp.22-27
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• 2009

The GPS(global positioning system) made up of 28 artificial satellites going round around the earth at a height of 20,000.Km is a system to determine the receiver's location by measuring the distance between the satellite and receivers using an electronic wave. Recently it's been widely used in various applications, such as a navigator, a surveying system, etc. In this paper, we propose a new algorithm to transform coordinates from GPS signals corresponding to various sizes of maps, and the application using this algorithm is also introduced. The algorithm is programmed by MFC on the WinCE 5.0 operating system, and the GPS receiver with a 20 channel high sensitivity and GPS microcontroller chip manufactured by SiRF Technology was used.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.884-886
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• 2022

본 논문에서는 GPS 기반의 자율주행 군사로봇에 사용된 각종 센서들의 융합(Sensor Fusion)에 대하여 다루고 있다. GPS 를 통한 자율주행의 경우 GPS 의 성능에 따라 정확도 차이는 있으나 특별한 지형지물 없이 로봇의 현재 위치를 파악할 수 있다는 장점이 있다. 하지만 GPS 만 이용하여 자율주행 알고리즘을 구성하는 경우 로봇의 진행 방향을 특정하지 못한다는 문제점이 발생한다. 이를 해결하기 위하여 본 논문에서는 RTK GPS 와 Lidar, IMU 센서를 ROS 환경에서 Robot_Localization 과 EKF(Extended Kalman Filter)를 이용하여 융합하는 방법에 대하여 다루었다.