• ICROS
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• v.3 no.2
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• pp.41-50
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• 1997

본 논문에서는 무궁화위성의 발사단계에서부터 궤도상 운용에 이르기까지 각 임무 단계별로 필요한 궤도제어 기법을 살펴보았다. 정지궤도 통신/방송 위성은 정지궤도 진입 및 정지궤도상에서 임무 수행을 위한 정밀 궤도 제어 등 궤도제어와 관련하여 궤도 결정과 함께 지상국용 임무설계 S/W를 필요로 한다. 정지궤도 위성의 이러한 궤도 제어 기술은 향후 국내의 자체 정지궤도 위성 개발시 관련 기술의 국산화에 많은 도움이 될 것으로 기대된다. 또한 현재 무궁화위성 1, 2호의 운용기술을 자체 습득하고 고도화하는 노력도 향후 계속되는 국내 수요에 대비하여 계속되어야 할 것이다.

• Journal of the Korean Institute of Intelligent Systems
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• v.26 no.4
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• pp.279-285
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• 2016

In this paper, a platform design of caterpillar typed electrical vehicle is proposed. Nowadays, there have been many researches on mobile robots in the various ways. Many different fields such as military, exploration, agricultural assistance and disaster relief have applied the mobile robot. Design condition of stable angle, upset angle is reflect to caterpillar typed electrical vehicle. To experiment, developed a caterpillar typed electrical vehicle and design a driving controller. Developed caterpillar typed electrical vehicle is tested about operating and driving. Test environment is consisted of driving on flatland and climbing 15 degree and outdoor 40 degree slope. It is confirmed that developed tracked electric vehicular robot can driving and climbing.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.3
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• pp.284-288
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• 2003

In this paper, a mobile robot system which have trajectory of metal tape- type is designed and manufactured. The mobile robot for manless-transportation consists of sensor-part with ultrasonic and infrared sensor, motor-part with motor and encoder, user interface-part, central control-part and computer interface-part. The ultrasonic sensor detects obstacles which can appear during the mobile robot is move. The infrared sensor has ability which detect the metal tape trajectory and then lead the robot to a correct position. By using the mobile robot, the flexiblity of a moving trajectory is improved and cost which can happen in using a mobile robot system having trajectory is cut as well.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.3
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• pp.275-282
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• 2015

Recently, Vecna BEAR type robot to save injured individuals from inaccessible areas has been developed to minimize the loss of life. Because this robot is driven on rough terrain, there is a risk of rollover and vibration, which could impact the injured. In order to guarantee its stability, an algorithm is required that can estimate the speed limits for various environments in real time. Therefore, a dynamic model for real-time analysis is needed for this algorithm. Because the tracks used as the driving component of Vecna BEAR type robot consist of many parts, it is impossible to analyze the multibody tracks in real time. Thus, a lumped track model that satisfies the requirements of a short computation time and adequate accuracy is required. This study performed lumped track modeling, and the traction force was verified using RecurDyn, which is a dynamic commercial program.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.2
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• pp.265-276
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• 2017

In this paper, a robust and more accurate trajectory tracking control method for a mobile robot is proposed using WIPDC(Weighted Integral Parallel Distributed Compensation) and T-S Fuzzy disturbance observer. WIPDC reduces the steady state error by adding weighted integral term to PDC. And, T-S Fuzzy disturbance observer makes it possible to estimate and cancel disturbances for a T-S fuzzy model system. As a result, the trajectory tracking controller based on T-S Fuzzy disturbance observer shows robust tracking performance. When the initial postures of a mobile robot and the reference trajectory are different, the initial control inputs to the mobile robot become too large to apply them practically. In this study, also, the problem is solved by designing an initial approach path using a path planning method which employs $B\acute{e}zier$ curve with acceleration limits. Performances of the proposed method are proved from the simulation results.

• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.3-6
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• 2003

뱀형 로봇은 일반적인 바퀴형 이동로봇과 운동 메카니즘이 상이하며 다관절로 이루어져 있기 때문에 장애물 회피에 있어 빠른 정보의 처리와 이를 위한 특별한 정보가 요구된다. 이를 실현하기 위하여 로봇은 자신의 위치를 지속적으로 파악하면서 장애물의 좌표 값과 일정한 거리의 간격을 두고 움직여야 한다. 주행 궤도 및 장애물 회피를 위한 알고리즘을 검증하기 위하여 가상 뱀형 시뮬레이터를 제작하였다. 시뮬레이터는 이동 주행 궤도를 생성하고, 지나온 궤도를 재현할 수 있는 재현기(Back Tracker), 앞으로 이루어질 뱀형 로봇의 위치와 자세를 알아보는 예견기(Predictor)로 구성된다. 시뮬레이터를 통하여 주위의 장애물을 안전하게 통과할 수 있는 일반적인 알고리즘인 포텐셜함수의 특성을 알아보고, 국소 최소점(Local Minima)에 빠지기 쉬운 단점을 극복하기 위한 방안을 제시한다. 본 논문에서는 뱀의 이동 주행 궤적을 알아보고, 주위의 장애물을 안전하게 통과할 수 있도록 하는 알고리즘에 대한 고찰과 제안한 알고리즘을 소프트웨어적인 3D 시뮬레이션을 통하여 걸과를 분석하고 검증한다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.6
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• pp.629-635
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• 2012

Tracked robots usually have poor localization performance because of slippage of their tracks. This study proposes a new localization method for tracked robots that uses fuzzy fusion of stereo-camera-based visual odometry and encoder-based wheel odometry. Visual odometry can be inaccurate when an insufficient number of visual features are available, while the encoder is prone to accumulating errors when large slips occur. To combine these two methods, the weight of each method was controlled by a fuzzy decision depending on the surrounding environment. The experimental results show that the proposed scheme improved the localization performance of a tracked robot.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.7
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• pp.1447-1456
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• 2011

In this paper, we propose a T-S fuzzy feedback linearization method for controlling a non-linear system with multi-input, and the method is applied for trajectory tracking control of wheeled mobile robot. First, an error dynamic equation of wheeled mobile robot is represented by a T-S fuzzy model, and then the T-S fuzzy model is transformed to a linear control system through the nonlinear fuzzy coordinate change and the nonlinear state feedback input. Simulation results showed that the trajectory tracking controller by using the proposed multi-input feedback linearization method gives better performance than the trajectory tracking controller by using the PDC(Parallel Distributed Compensation) method for controlling the T-S Fuzzy system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.7
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• pp.1694-1704
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• 2015

In this paper, a robust trajectory tracking control method of a wheeled mobile robot is newly proposed combining the PDC and the ISMC. The PDC is a relatively simple and easy control method for nonlinear system compared to the other non-linear control methods. And the ISMC can have robust and stable control characteristics against model uncertainties and disturbances from the initial time by placing the states on the sliding plane with desired nominal dynamics. Therefore, the proposed PDC+ISMC trajectory tracking control method shows robust trajectory tracking performance in spite of external disturbance. The tracking performance of the proposed method is verified through simulations. Even though the disturbance increases, the proposed method keeps the performance of the PDC method when there is no disturbance. However, the PDC trajectory tracking control method has increasing tracking error unlike the proposed method when the disturbance increases.

• Transactions of the Korean Society of Mechanical Engineers
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• v.9 no.4
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• pp.509-517
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• 1985

작업 공간내에서 원하는 속도와 가속도로, 주어진 경로를 따라 이동하는 k차원 좌표계를 구성하고, 메니퓰레이터의 운동 방정식을 이 좌표계로 변환하여 운동 경로에 대한 선형화 식을 구하였다. 이 시스템의 입력을 변위와 속도의 함수로 정의한 후 안정성을 고려하여 이득을 결정하여 비례-적분제어 시스템을 구성하였다. 이와 같이 구한 적응 제어 알고리즘은 메니퓰레이터의 동적 특성에 대한 정확한 지식을 요하지 않고 또 계산이 간단하여 실시간 응용이 가능하다. 예로서 3차원 공간상의 반경 10cm의 원궤도에 적용하였을 때 최대 오차는 대략 1mm이었으며 상황 변화에 무감각함을 보였다.