• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.10a
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• pp.171-171
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• 2003

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.10a
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• pp.95-95
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• 2003

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.13-13
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• 1997

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.5
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• pp.706-711
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• 2008

This paper is presented an accurate localization scheme for mobile robots based on the fusion of ultrasonic satellite (U-SAT) with inertial navigation system (INS), i.e., sensor fusion. Our aim is to achieve enough accuracy less than 100 mm. The INS consist of a yaw gyro, two wheel-encoders. And the U-SAT consist of four transmitters, a receiver. Besides the localization method in this paper fuse these in an extended Kalman filter. The performance of the localization is verified by simulation and two actual data(straight, curve) gathered from about 0.5 m/s of driving actual driving data. localization methods used are general sensor fusion and sensor fusion through Kalman filter using data from INS. Through the simulation and actual data studies, the experiment show the effectiveness of the proposed method for autonomous mobile robots.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.5
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• pp.186-201
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• 2021

As autonomous driving technology advances, the accuracy of the vehicle position is important for recognizing the environments around driving. Map-matching localization techniques based on high definition (HD) maps have been studied to improve localization accuracy. Because conventional map-matching techniques estimate the vehicle position based on an HD map reference dataset representing the center of the lane, the estimated position does not reflect the deviation of the lateral distance within the lane. Therefore, this paper proposes a localization system based on the reference lateral position dataset extracted using image processing and HD maps. Image processing extracts the driving lane number using inverse perspective mapping, multi-lane detection, and yellow central lane detection. The lane departure method estimates the lateral distance within the lane. To collect the lateral position reference dataset, this approach involves two processes: (i) the link and lane node is extracted based on the lane number obtained from image processing and position from GNSS/INS, and (ii) the lateral position is matched with the extracted link and lane node. Finally, the vehicle position is estimated by matching the GNSS/INS local trajectory and the reference lateral position dataset. The performance of the proposed method was evaluated by experiments carried out on a highway environment. It was confirmed that the proposed method improves accuracy by about 1.0m compared to GNSS / INS, and improves accuracy by about 0.04m~0.21m (7~30%) for each section when compared with the existing lane-level map matching method.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.3
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• pp.487-498
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• 2013

A variety of location-based services applications, such as missing children search, emergency rescue requests and so on that requiring high-precision location information are increasing. Precision of GPS that can be used in most systems, however, is still low. In this paper, we design and propose a low cost differential global positioning system(DGPS) based on Web services using object-oriented modeling technique which can offer useable location service, variety device and safe service in wireless environment. The proposed system is designed with UML based on object-oriented modeling to maximize system recyclability and system scalability. In addition, we would like to improve the precision of the GPS in accordance with mobile station location when build low cost mobile station, location differential framework and server. We implement a communication interface based on web-service which is available in the form of a variety of services and can offer stable according to mobile environments. Finally, as performance evaluation results, we can obtain precision location within 1 ~ 2m through proposed system and 88.5% probability of less than 2m.

• Journal of Astronomy and Space Sciences
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• v.14 no.2
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• pp.375-380
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• 1997

The accuracy of user position by GPS is heavily dependent upon the accuracy of satellite position which is usually transmitted to GPS users in radio signals. The real-time satellite position information directly obtained from broadcast ephimerides has the accuracy of 3~10 meters which is very unsatisfactory to measure 100km baseline to the accuracy of less than a few mili-meters. There are globally at present seven orbit analysis centers capable of generating precise GPS ephimerides and their orbit quality is of the order of about 10cm. Therefore, precise orbit model and phase processing technique were reviewed and consequently precise GPS ephimerides were produced after processing the phase observables of 28 global GPS stations for 1 day. Initial 6 orbit parameters and 2 solar radiation coefficients were estimated using batch least square algorithm and the final results were compared with the orbit of IGS, the International GPS Service for Goedynamics.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.4
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• pp.181-199
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• 2022

This study presented a methodology for evaluating the performance of the lane departure warning system was derived by calculating the relationship between the behavior information of the car and the location of the high-precision map using a high-precision map. The evaluation criteria of the mood and lane departure warning system for the installation of road markings in Korea were analyzed, a high-precision map was constructed to meet the evaluation criteria, and an evaluation system was constructed to verify the proposed methodology. Evaluation of lane departure warning systems using high-precision maps can be quantified and applied to various road environments through accurate location-based comparative analysis and reduced manual post-processing work time to confirm evaluation results.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.8
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• pp.1779-1788
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• 2012

Recently, demands of application services in consideration of interior environment according to the stream of times, Ubiquitous. In case of interior location-based service, WLAN is now mostly used. But it is largely affected by environmental changes. To solve this problem, lots of studies on UWB are underway. The reason why studies on UWB are much made lies in that it is not much affected by environment changes owing to radio wave characteristics. So this study suggests the location correction algorithm which derives values with less influence of environment and high accuracy and corrects with more accurate location information using Ubisense system based on UWB technologies. The location correction algorithm suggested is one made after constructing environment database and use it to estimate more accurate location from the location measuring system in a high position.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.10
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• pp.88-93
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• 1996

The study was carried out development a pricision positioning apparatus, consisting of DG servo motor and piezoelectric actuatior. This system is composed of fine and coarse apparatus, measurement system and control system. Peezoelectric actuator is designed for fine positioning. Coarse positioning using lead screw is droved by DC servo motor. Control system output a signal from laser interfermeter and capacitive sensor to amplifer of DC servo motor and piezoelectric actuator after digital signal processing (DSP). Resolution of this apparatus measure with laser interferometer and microsense