• 한국정밀공학회지
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• 제25권10호
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• pp.58-66
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• 2008

In the development of intelligent vehicles, path tracking of unmanned vehicle is a basis of autonomous driving and automatic navigation. It is very important to find the exact position of a vehicle for the path tracking, and it is possible to get the position information from GPS. However the information of GPS is not the current position but the past position because a vehicle is moving and GPS has a time delay. In this paper, therefore, the moving distance of a vehicle is estimated using a direction sensor and a velocity sensor to compensate the position error of GPS. In the steering control, optimal fuzzy rules for the path tracking can be found through the simulation of Simulink. Real driving experiments show the fuzzy rules are good for the steering control and the position error of GPS is well compensated by the proposed estimation method.

• 전기학회논문지
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• 제59권3호
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• pp.645-650
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• 2010

In this paper we present the Bimodal-tram simulator using the PXI embedded real-time controllers. The Bimodal-tram is developed in KRRI (Korea Railroad Research Institute). The vehicle can be automatically operated by navigation control system (NCS). For the automatic driving, the vehicle lanes will be marked with permanent magnets that are placed in the ground. The vehicle is controlled by NCS. NCS governs the manual mode and automatic mode driving. The simulator is designed by an identical conception with the real control condition. The dynamic motion of vehicle is simulated by the nonlinear dynamic model. The control computer calculates the control values. The signal interface is linked by CAN communication. The simulation is processed by real-time base. The test driver can see the graphic motion of vehicle and can operate the steering wheel, gas and brake pedal to control direction and velocity of vehicle during the simulation. At present, the simulator is only operated by manual mode. The automatic mode will be linked after the control algorithm is finished. We will use the simulator to develop the control algorithm in the automatic mode. This paper shows the simulator designed for Bimodal-tram using real-time based controller. The results of the test using the simulator are presented and discussed.

• Agricultural and Biosystems Engineering
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• 제4권1호
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• pp.22-27
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• 2003

An autonomous tractor requires not only automatic steering (automatic guidance) but also automated control of tractor functions and implement operations. Examples of tractor functions include engine throttle, transmission speed, and 3-point hitch position. Implement operations include tillage, planting, and cultivating. This article provides an overview of a map-based methodology used for the implementation of autonomous field operations of agricultural tractors. The procedure for developing autonomous field operation maps were presented, and several important issues in the implementation of map-based autonomous operations were discussed. These issues included combining field operation maps, position offset, and real-time sensing and update of field operation maps.

• 한국항해항만학회지
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• 제26권2호
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• pp.193-197
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• 2002

선박 조종방정식의 비선형 요소를 고려한 선박의 자동조타시스템의 제어기를 설계하기 위하여 TSK (Takagj-Sugeno-Kang) 퍼지 이론을 이용하였다. TSK 퍼지모델은 비선형 시스템을 매우 효율적으로 표현할 수 있으며, 또 TSK 퍼지모델은 결론부가 선형식으로 이뤄져 있어 체계적인 제어기 설계가 가능하다. 따라서 본 연구에서는 선박의 조종방정식을 TSK 퍼지모델로 표현하는 방법과 그 모델로부터 체계적으로 TSK 퍼지제어기를 설계하는 방법을 설명한다.

• Journal of Biosystems Engineering
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• 제24권3호
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• pp.209-216
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• 1999

A self-travelling sprayer was developed to avoid the exposure of an operator to agricultural chemicals and exhaust gas, to improve safety and to increase working efficiency during the application and transport work in the greenhouses. This system consists of self-travelling system and the control system for application and safety device. The auto-spray car is equipped with a liquid chemical tank of 80l capacity. The travelling system adopted mechanical steering system which link mechanism of front wheel is guided by guide rollers. The sprayer travels along the guiding pipe which is set on the furrow in the greenhouses. The sprayer stops automatically applying and traveling when the liquid chemical tank becomes empty or when the sprayer reach the turning point. The spray booms swings in a vertical plane. The control system of safety devices controls the automatic stop of the sprayer when there is an obstacle on the traveling path, or when the battery becomes discharged. The auto-spray car traveled smoothly and steadily along the guide pipe during traveling straightly and turning on the ground.

• 한국지능시스템학회논문지
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• 제24권1호
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• pp.33-39
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• 2014

자동 주행 차량을 구현하기 위해서는 장애물 인식, 차선 인식 및 변경 등 많은 기능들이 필요하다. 본 논문에서는 자동차 주행에 필요한 '차선 인식'의 범위를 확장시킨 '색깔 인식' 개념을 도입 적용시키기 위해 3가지 코스를 주행하는 시스템을 구현하였다. RC car의 크기와 비례하게 축소 제작한 각 코스에서 주행에 필요한 검지선의 위치, 기울기 및 차량의 속도를 고려하여 조향 제어를 하였고, 브레이크 기능이 없는 RC car를 제어하기 위해 차량의 속도와 검지선의 위치를 고려하였다.

• International Journal of Control, Automation, and Systems
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• 제6권3호
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• pp.434-443
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• 2008

This paper develops a novel automatic parking algorithm based on a fuzzy logic controller with the vehicle pose for the input and the steering rate for the output. It localizes the vehicle by using only external sensors - a vision sensor and ultrasonic sensors. Then it automatically learns an optimal fuzzy if-then rule set from the training data, using an evolutionary fuzzy system. Furthermore, it also finds the green zone for the ready-to-reverse position in which parking is possible just by reversing. It has been tested on a 4-wheeled Pioneer mobile robot which emulates the real vehicle.

• Journal of Biosystems Engineering
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• 제21권4호
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• pp.422-428
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• 1996

This study was conducted to developed to develop a simple battery-powered autonomous vehicle for greenhouse works. A steering method using speed difference of two independent driving motors was adopted. DC motor driving circuit, speed control circuit and controller using one-chip microcomputer were constructed. The inputs of controller are rolling of the vehicle and current speed of driving motors. Using these signals, automatic guidance system along furrow was developed. A computer simulation program by the kenematic analysis was developed to find out optimal control algorithm. The results of this study are as follows. 1. Automatic guidance system along the furrow that adopted two independent driving motors and rolling of vehicle was developed. 2. The results of simulation showed that PID control was adequate to automatic guidance system along furrow. 3. Two commercial 12V battery serially connected were able to drive the vehicle on the soil ground for five hours in continuous operation and for four hours in intermittent operation without recharging the battery. 4. The speed range was 0-0.7m/s and the rolling of vehicle could be controlled within $pm5^{\circ}$ range. 5. From a series of tests, developed vehicle was found to be a useful tool for greenhouse works.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 B
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• pp.972-975
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• 1999

Until now, all of the port goods are transported by container transporter driven manually but recently there are a lot of researches about unmanned vehicle driven automatically. In this paper, we present a design of the TDOF PID controller using a hybrid schematic algorithm to control steering system. We used the ES and SA algorithms to construct hybrid tuning algorithm. Then the computer simulation shows that our proposed controller has better Performances than the other one.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2016년도 춘계학술대회
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• pp.308-309
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• 2016

본 논문은 선박의 자동항법 시스템에서 주요한 부분인 항로추종 유도 기법을 다루고 있다. 특히, 웨이포인트(way-point)기반, 인클로져(enclosure)기반, 룩어헤드(lookahead)기반의 항로추종 유도기법의 성능에 관해 살펴본다. 아울러 본 논문에서는 항로추종 시 선박의 조타제어를 위해 PID제어 시스템이 적용된다. 최종적으로 3가지 유도기법의 성능은 시뮬레이션 결과를 통해 평가된다.