• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.633-637
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• 2007

Bimodal Tram is the newly developed vehicle for both the tracked way and the public road. Its operation system has some characteristics including BIS(bus information system)/BMS(bus management system) based on ITS(intelligent Transportation system) which is used presently in public transportation operation system. One of them is more accurate vehicle fleet control based on both magnetic maker position reference system and GPS(global positioning system) and the other is automatic vehicle control for emergency situations by the Bimodal Tram operation system which will be performed by the unified control and operation center. This paper has investigated the requirements and functional definitions necessary to construct the unified control and operation center for Bimodal Tram operation system which will be more efficient and secure public transportation system than the conventional ones.

• 산업경영시스템학회지
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• 제44권4호
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• pp.145-153
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• 2021

Automated Guided Vehicle (AGV) is commonly used in manufacturing plant, warehouse, distribution center, and terminal. AGV is self-driven vehicle used to transport material between workstations in the shop floor without the help of an operator, and AGV includes a material transfer system located on the top and driving system at the bottom to move the vehicle as desired. For navigation, AGV mostly uses lane paths, signal paths or signal beacons. Various predominant sensors are also used in the AGV. However, in the conventional AGV, there is a problem of not turning or damaging nearby objects or AGV in a narrow space. In this paper, a new driving system is proposed to move the vehicle in a narrow space. In the proposed driving system, two sets of the combined steering-drive unit are adopted to solve the above problem. A prototype of AGV with the new driving system is developed for the comparative analysis with the conventional AGV. In addition, the experimental result shows the improved performance of the new driving system in the maximum speed, braking distance and positioning precision tests.

• 대한원격탐사학회지
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• 제34권6_1호
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• pp.1131-1142
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• 2018

자율주행차는 교통사고로 인한 인명피해나, 운전으로 인해 발생하는 시간 및 비용을 줄일 수 있는 장점 때문에 개발 및 운용이 확대되고 있다. 이러한 자율주행차의 운행을 위해서는 정밀한 측위가 필수적이다. 본 연구에서는 고가의 센서를 사용하지 않고 차량 내장센서, 위성센서, 영상센서와 사전에 구축해둔 기준영상 정보를 통합하여 차량의 위치를 정밀하게 추정하는 알고리즘을 개발하였다. 기준영상 정보는 센서 정보만 사용하였을 경우 발생하는 측위 정밀도 한계를 극복할 수 있으며, 위성신호 단절과 같은 문제 발생시에도 안정적으로 취득이 가능한 장점이 있다. 센서 및 기준영상 정보를 결합하기 위한 필터는 개별 센서의 다양한 확률 밀도 분포를 반영할 수 있는 파티클 필터를 사용하였다. 알고리즘의 성능평가를 위해 데이터 취득 시스템을 구축하고 이를 이용한 주행 데이터 및 기준영상 정보를 취득하였다. 위성센서에 의한 오차가 비교적 큰 주행 경로에 대해서도 주행영상 및 기준영상 정보를 함께 결합할 경우 약 0.7 m 이내의 정확도로 차량 측위가 가능함을 확인하였다.

• International Journal of Automotive Technology
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• 제8권5호
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• pp.583-591
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• 2007

This paper describes the development of the $H_{\infty}$ lateral control system for an autonomous ground vehicle operating a limited area using the RTK-DGPS(Real Time Kinematic-Differential Global Positioning System). Before engaging in autonomous driving, map data are acquired by the RTK-DGPS and used to construct a reference trajectory. The navigation system contains the map data and computes the reference yaw angle of the vehicle using two consecutive position values. The yaw angle of the vehicle is controlled by the $H_{\infty}$ controller. A prototype of the autonomous vehicle by the navigation method has been developed, and the performance of the vehicle has been evaluated by experiment. The experimental results show that the $H_{\infty}$ controller and the RTK-DGPS based navigation system can sufficiently track the map at low speed. We expect that this navigation system can be made more accurate by incorporating additional sensors.

• 디지털산업정보학회논문지
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• 제9권4호
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• pp.69-79
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• 2013

A system of tracking a vehicle collects the vehicle location and then transmits the data into a GIS server in order to provide several service areas. An ODU built in the vehicle savesa GPS information data and communicates with the RSU installed in the road over the wave technology. The collected data in RSU is transmitted into the GIS serverand is stored. The system based on the collected GPS data in each vehicle is providing useful and various services between RSU and OBU. In this paper indicates that the system is designed in 2 phasesbased on the collected GPS data. The result comparing to process of GPS data created in 1 phase and 2 phase over the Web GIS service indicates that the capability of process of the GPS data in 2 phase is enhanced in "50.88% ~ 51.81%". Therefore, when the accident is happened the system of tracking the vehicle over GPS tech not only receives the information properly but also provides the emergence rescue services.

• 로봇학회논문지
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• 제8권1호
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• pp.29-36
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• 2013

This paper presents a sensitivity optimization of a MEMS (microelectromechanical systems) gyroscope for a magnet-gyro system. The magnet-gyro system, which is a guidance system for a AGV (automatic or automated guided vehicle), uses a magnet positioning system and a yaw gyroscope. The magnet positioning system measures magnetism of a cylindrical magnet embedded on the floor, and AGV is guided by the motion direction angle calculated with the measured magnetism. If the magnet positioning system does not measure the magnetism, the AGV is guided by using angular velocity measured with the gyroscope. The gyroscope used for the magnet-gyro system is usually MEMS type. Because the MEMS gyroscope is made from the process technology in semiconductor device fabrication, it has small size, low-power and low price. However, the MEMS gyroscope has drift phenomenon caused by noise and calculation error. Precision ADC (analog to digital converter) and accurate sensitivity are needed to minimize the drift phenomenon. Therefore, this paper proposes the method of the sensitivity optimization of the MEMS gyroscope using DEAS (dynamic encoding algorithm for searches). For experiment, we used the AGV mounted with a laser navigation system which is able to measure accurate position of the AGV and compared result by the sensitivity value calculated by the proposed method with result by the sensitivity in specification of the MEMS gyroscope. In experimental results, we verified that the sensitivity value through the proposed method can calculate more accurate motion direction angle of the AGV.

• 한국항해항만학회지
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• 제26권3호
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• pp.303-310
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• 2002

현재 범세계위치결정체계(GPS)와 추측항법(DR), 기타 장치를 결합한 육상차량항법시스템이 사용되고 있다. 그리고 GPS는 육상항법시스템으로 널리 이용되고 있지만, 도심지 등에서 가시위성의 부족으로 차량의 동적 위치결정에 적절하지 못하다. 따라서 본 연구에서는 GPS의 단점을 보완하기 위해 GPS/GLONASS 결합항법시스템을 이용하여 차량의 동적위치를 결정하였다. 실험결과 도심지에서 많은 장애물과 가시위성에도 불구하고 GLONASS 위성의 부가로 높은 자료획득률을 보여 GPS/GLONASS의 결합항법시스템으로 차량의 동적 위치를 연속적으로 획득할 수 있었다. 그러므로 GPS/GLONASS 결합항법시스템은 도로의 교통흐름의 통제와 효율적 관리에 응용할 수 있을 것으로 사료된다.

• 제어로봇시스템학회논문지
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• 제14권1호
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• pp.27-35
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• 2008

A navigation system is one of the important components of an unmanned ground vehicle (UGV). A GPS receiver collects data signals transmitted by (Earth orbiting) satellites. However, these data signals may contain many errors resulting misinformation and depending on one's position (environment), reception may be impossible. The proposed self-driven algorithm uses three low-cost GPS in order to minimize errors of existing inexpensive single GPS's driving algorithm. By using reliable final data, which is analyzed and combined from each of three GPS's received data signals, gathering a vehicle's steering performance information and its current pin-point position is improved even with error containing signals or from a place where signal gathering is impossible. The purpose of this thesis is to explain navigation system algorithm using multiple GPS and compass sensor and prove the algorithm through experiments.

• 자동차안전학회지
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• 제12권3호
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• pp.34-42
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• 2020

ADAS (Advanced Driver Assistance Systems) uses sensors such as camera, radar, lidar and GPS (Global Positioning System). Among these sensors, the camera has many advantages compared with other sensors. The reason is that it is cheap, easy to use and can identify objects. In this paper, therefore, a theoretical formula was proposed to obtain the distance from the vehicle's front wheel to the lane using a monocular camera. And the validity of the theoretical formula was verified through the actual vehicle test. The results of the actual vehicle test in scenario 4 resulted in a maximum error of 0.21 m. The reason is that it is difficult to detect the lane in the curved road, and it is judged that errors occurred due to the occurrence of significant yaw rates. The maximum error occurred in curve road condition, but the error decreased after lane return. Therefore, the proposed theoretical formula makes it possible to assess the safety of the LKA system.

• 디지털산업정보학회논문지
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• 제12권2호
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• pp.15-24
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• 2016

GPS(Global Positioning System) location tracking is a method for taking the precise coordinates after the coordinates are obtained by a GPS receiver, and displaying them on the map. In this paper with WAVE(Wireless Access for Vehicular Environment) simulation, we show that various services such as vehicle tracking service, real-time road conditions service and logistics can go tracking service, control and operation services according to the vehicle position and the traveling direction by using the GPS position data. A vehicle tracking system using GPS is automatically able to manage multiple RCP when exchanging data between RMA and the RCP, and it provides rapid requests and responses. To verify that multiple sessions between RMA and RM, as well as multiple sessions between RMA and RCP are able to be implemented, we take RMA as a RCP application on an OBU, until the RMA is receiving data response from corresponding RM. As a result of this experiment, we show that the response speeds of single session between RMA and RM using 1, 2, 3, and 4 kbyte unit data are similar, 62.32ms, 62.65ms, 63.02ms, and 63.48ms, respectively. Likewise, those of 128 muliple sessions using 1, 2, 3, and 4 kbyte unit data are not much more time difference, 298.08ms, 302.21ms, 322.85ms, and 329.62ms, respectively.