• 한국CDE학회논문집
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• 제20권3호
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• pp.298-311
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• 2015

Nowadays, automatic digging operation of an excavator is a big challenge due to the complexity of digging environment, the hardness of soil and buried obstacles into the ground. In order to achieve the maximum soil bucket volume, this paper introduces a novel engineering model that was developed as a virtual excavator in the design phase. Through this model, the designs of mechanical and control systems for autonomous excavator are executed and modified easily before developing in real testbed. Based on a concept of an autonomous excavation, a mechanical system of excavator was first designed in SOLIDWORKS, and a soil model also was modeled by finite-element analysis in ANSYS, both modeled models were then exported to ADAMS environment to investigate the digging behavior through virtual simulation. An intelligent control strategy was generated in MATLAB/Simulink to control the excavator operation. The simulation results were demonstrated by effectiveness of the proposed excavator robot in testing scenarios with many soil types and obstacles.

• 조명전기설비학회논문지
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• 제22권4호
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• pp.19-25
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• 2008

본 논문은 장애물에 대한 사전 정보를 가지고 있지 않은 미지의 공간에서 장애물의 회피와 지정된 목표점으로 이동할 수 있는 자율이동로봇을 위한 퍼지-뉴럴 네트워크를 이용한 지능제어 알고리즘을 제안하고, 제안된 제어기의 효용성을 모의실험과 실제 로봇의 구동실험을 통하여 검증을 한다. 제시한 지능제어기는 계층구조의 알고리즘으로 로봇이 목표에 도달하기 위한 퍼지 알고리즘과 주행 중 만날 수 있는 장애물들에 대한 회피를 수행하는 퍼지-뉴럴 알고리즘으로 구성된 계층과, 로봇이 이동하면서 만날 수 있는 여러 가지 상황에 따라 장애물 회피동작과 목표점 도달동작을 수행할 수 있도록 두 알고리즘에 적당한 가중치를 부여하는 가중치 퍼지 알고리즘으로 구성되어 있다. 그리고 로봇의 현재 운동정보와 장애물까지의 거리정보를 바탕으로 가중치 퍼지 알고리즘의 출력부 소속도 함수를 조절함으로서 오목한 장애물에 대해서도 장애물 회피 동작을 수행하도록 하였다. 제작된 로봇으로 제시한 알고리즘의 실효성을 검증하였다.

• 한국지능시스템학회논문지
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• 제13권1호
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• pp.18-23
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• 2003

본 논문에서는 미지의 환경에서 비전 시스템을 갖는 이동로봇이 자율 주행을 할 수 있도록 하는 경로 계획 및 장애물 회피 알고리즘을 제안하고자 한다. 거리 변화율 기법을 이용하여 임시 목표물을 설정한 다음, 퍼지규칙을 이용하여 이동 로봇의 자율 주행을 위한 경로 설정과 근접 장애물 회피를 위한 알고리즘을 구현하였다 여러 환경에서의 모의 실험을 통해 본 논문에서 제안된 알고리즘의 성능을 시험하였으며, 그 결과 복잡한 주변 환경에서도 좋은 성능을 나타냄을 확인 할 수 있었다. 또한 제안된 알고리즘의 효율성을 실제 시스템에 적용하기 위해 이동로봇을 제작하여 검증한 결과 모의 실험 때와 마찬가지로 만족할 만한 성능을 나타냄을 확인할 수 있었다.

• 자동차안전학회지
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• 제15권3호
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• pp.53-58
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• 2023

Defects in the vehicle itself were considered the biggest risk factor for traffic accidents as the electrical and electronic components of vehicles, which were not there before, increase. Therefore, the vehicles have been developed based on ISO 26262 (an international functional safety standard) which is focusing on functional defect safety evaluation of electrical and electronic component systems. However, in the future, as autonomous driving technology is applied, even vehicles without functional defects must be prepared for the dangerous traffic situation that may arise from exceptional or external factors. SOTIF (Safety Of The Intended Functionality) is a concept to prevent exceptional or external factors. The main objective of SOTIF is to decrease Unknown & Unsafe factors as much as possible by finding Known factors and Unsafe factors. In this study, Prescan provided SIEMENS, one of the autonomous driving simulators, is used to make scenarios of IGLAD traffic accident cases. From the simulation results, Unsafe & Safe cases were classified and analyzed to derive unsafe factors.

• 자동차안전학회지
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• 제15권2호
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• pp.6-12
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• 2023

For the commercialization and standardization of autonomous vehicles, demand for rigorous safety criteria has been increased over the world. In Korea, the number of extraordinary service permission for automated vehicles has risen since Hyundai Motor Company got its initial license in March 2016. Nevertheless, licensing standards and evaluation factors are still insufficient for operating on public roadways. To assure driving safety, it is significant to verify whether or not the vehicle's decision is similar to human driving. This paper validates the safety of the autonomous vehicle by drawing scenario-based comparisons between manual driving and autonomous driving. In consideration of real traffic situations and safety priority, seven scenarios were chosen and classified into basic and advanced scenarios. All scenarios and safety factors are constructed based on existing ADAS requirements and investigated via a computer simulation and actual experiment. The input data was collected by an experimental vehicle test on the SNU FMTC test track located at Siheung. Then the offline simulation was conducted to verify the output was appropriate and comparable to the manual driving data.

• 대한조선학회논문집
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• 제60권6호
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• pp.406-415
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• 2023

In this study, we focused on developing and verifying ship collision avoidance algorithms using Unity simulator and ROS(Robot Operating System). ROS is used to establish an environment where communication between different operating systems is possible, and a dynamic model of a ship is constructed within Unity simulator. The Lidar data collected in Unity environment is passed to the system based on python through ROS. In the system based on python, control command values were created through the logic of the collision avoidance algorithm using data, and the values were transferred back to Unity to control the movement of the virtual ship. Through the developed simulation system, the reliability of the collision avoidance algorithm of ships with two different forms in an environment similar to the actual physical world was confirmed. As a result, it was confirmed on the simulator that it could be avoided without collision even in an environment with various types of obstacles, and that the avoidance characteristics according to the dynamics of the ship could be analyzed.

• 자동차안전학회지
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• 제15권4호
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• pp.39-47
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• 2023

Research on the safety of autonomous vehicle is being conducted in various countries, including the European Union, and computer simulation techniques so called 'Virtual Tool Chain' are mainly used. As part of the crash safety study of autonomous vehicle, 25 car to car collision scenarios were provided as a result of a real accident-based accident reproduction analysis study conducted by a domestic research institution, and a vehicle crash analysis was performed using the FE car to car model of the Honda Accord. In order to analyze the results of the car to car simulation and to construct a database, major crash parameters were selected as impact speed, angle, location, and overlap, and a method of defining them in an indexed form was presented. In order to compare the crash severity of each scenario, a value obtained by integrating the resultant acceleration measured by the ACU of the vehicle was applied. The equivalent collision test mode was derived by comparing the crash severity of the regulation test mode, 30 deg rigid barrier mode, in the same way.

• 대한임베디드공학회논문지
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• 제19권3호
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• pp.131-139
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• 2024

Crew Transfer Vessels (CTVs) are primarily used for the maintenance of offshore wind farms. Despite being manually operated by professional captains and crew, collisions with other ships and marine structures still occur. To prevent this, the introduction of autonomous navigation systems to CTVs is necessary. In this study, research on the obstacle avoidance system of the autonomous navigation system for CTVs was conducted. In particular, research on obstacle avoidance simulation for CTVs using deep reinforcement learning was carried out, taking into account the currents and wind loads in offshore wind farms. For this purpose, 3 degrees of freedom ship maneuvering modeling for CTVs considering the currents and wind loads in offshore wind farms was performed, and a simulation environment for offshore wind farms was implemented to train and test the deep reinforcement learning agent. Specifically, this study conducted research on obstacle avoidance maneuvers using MATD3 within deep reinforcement learning, and as a result, it was confirmed that the model, which underwent training over 10,000 episodes, could successfully avoid both static and moving obstacles. This confirms the conclusion that the application of the methods proposed in this study can successfully facilitate obstacle avoidance for autonomous navigation CTVs within offshore wind farms.

• 정보처리학회논문지B
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• 제10B권4호
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• pp.403-410
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• 2003

자율운항제어 시스템은 선박운항에 있어 항해계획을 수립하고 현재의 선박운항 상태를 파악하여 선박을 제어하는 항해 전문가 시스템이다. 이러한 자율운항제어 시스템을 테스트하기 위해서는 실제 선박을 대상으로 성능을 테스트하여야하나, 선박은 고가의 운송수단이고, 자율운항제어 시스템을 장착하기 위한 하부장치 인터페이스를 설계 및 구현하기에는 많은 시간이 소요되므로 선박시뮬레이션 시스템을 이용하는 것이 타당하다. 선박시뮬레이션 시스템은 선박의 물리적 운항특성을 모방하는 선박운동시뮬레이션 시스템과 선박 운항 주변에 변화하는 장애물을 시뮬레이션하는 주변객체 시뮬레이션 시스템으로 구성된다. 본 연구에서는 선박 운동방정식을 이용하여 선박의 물리적 및 운항 특성을 모방한 선박운동시뮬레이션 시스템을 설계 개발하였다.

• 산업경영시스템학회지
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• 제17권29호
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• pp.63-78
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• 1994

Today, the problem of interrational competition has been strongly appeared and as the deflation is deep occasionally, it is sure that granting autonomous motivation of businessman or importance of self development is proposed especially. Then, which subject is included in granting autonomous motivation as that\ulcorner We must study about that subject first. First, we should study about essence of granting autonomous motivation. Granting autonomous motivation is the course of accompli¬shment of ideal human individually. Secondly, we will divide that into goal, desire and positive attitude subjectly and will study about those respectively. Contents of this theory are as below. 1. Proposal of problem 2. Basic structure of granting autonomous motivation and ability 2-1 Consideration of granting autonomous motivation 2-2 Basic structure of ability 3. The method of granting autonomous motivation 3-1 Simulation of granting autonomous motivation 3-2 Establishment of subject on granting autonomous motivation 4. Granting autonomous motivation by utilization of opportunity 4-1 Utilization of opportunity 4-2 Self-development by reading 4-3 Self development by writing 4-4 Self-development by discussion 4-5 Self development by control of health 4-6 Self-development by making the time 5. Conclusion This theory will be developed by classification as above. Reflecting many times and experiencing a skill for himself, he should teach his men the skill. There are some men not to be able to talk with, but a businessman should make his surroundings cheerful with granting autonomous motivation. If he understands the men of his surroundings with his positive attitude, all tasks of him will be achieved. Formation of question consciousness that he can study always, is needed on which is the important task in himself.