• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.1
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• pp.98-106
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• 1991

Future generation of robots will be considerably more autonomous than present robotic systems. The main objective of research on theoretical problems in robotics is to endow robotics system with basic capabilities they will need to operate in an intelligent and autonomous manner. This paper discusses the problem of collision free movement of robot manipulator. It is formulated in path planning with obstacle avoidance expressed in the term of the distance between convex shapes in the three dimensional space. The examples are given to illustrate the main feature of the method.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.199.2-199.2
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• 2005

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2004.11a
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• pp.163-168
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• 2004

The purpose of this study is to analyse the climatic characteristic of South Korea and use it as a fundamental data for planning an environmental housing complex in Seoul, the capital of South Korea. The world after the Industrial Revolution has greatly developed economically but falied to notice the importance of the environment. It has been gradually damaged by the reckless exploitation for tens of years, and thus inflicted a loss on human. In this study, necessity and usability of the application of the climatic element for planning the environmental housing complex are to be presented. The data used in this study are given by the Met.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.7
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• pp.557-564
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• 2021

This paper describes an automatic landing approach algorithm for fixed-wing UAVs using waypoint guidance. The proposed algorithm utilizes simple 2D Dubin's vehicle pre-simulations in planning the waypoints for landing approach. The remaining time to reach the runway is also estimated in the pre-simulation, and it is used for altitude control. The performance of the designed algorithm was verified by simulations and flight tests.

• Journal of Auto-vehicle Safety Association
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• v.11 no.3
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• pp.30-36
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• 2019

This paper suggests a car-following algorithm for urban environment, with multiple target candidates. Until now, advanced driver assistant systems (ADASs) and self-driving technologies have been researched to cope with diverse possible scenarios. Among them, car-following driving has been formed the groundwork of autonomous vehicle for its integrity and flexibility to other modes such as smart cruise system (SCC) and platooning. Although the field has a rich history, most researches has been focused on the shape of target trajectory, such as the order of interpolated polynomial, in simple single-lane situation. However, to introduce the car-following mode in urban environment, realistic situation should be reflected: multi-lane road, target's unstable driving tendency, obstacles. Therefore, the suggested car-following system includes both in-lane preceding vehicle and other factors such as side-lane targets. The algorithm is comprised of three parts: path candidate generation and optimal trajectory selection. In the first part, initial guesses of desired paths are calculated as polynomial function connecting host vehicle's state and vicinal vehicle's predicted future states. In the second part, final target trajectory is selected using quadratic cost function reflecting safeness, control input efficiency, and initial objective such as velocity. Finally, adjusted path and control input are calculated using model predictive control (MPC). The suggested algorithm's performance is verified using off-line simulation using Matlab; the results shows reasonable car-following motion planning.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.3
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• pp.217-225
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• 2016

In this paper, we propose an improved path planning method and obstacle avoidance algorithm for two-wheel mobile robots, which can be effectively applied in an environment where obstacles can be represented by circles. Firstly, we briefly introduce the rapidly exploring random tree (RRT) and single polar polynomial (SPP) algorithm. Secondly, we present additional two methods for applying our proposed method. Thirdly, we propose a global path planning, smoothing and obstacle avoidance method that combines the RRT and SPP algorithms. Finally, we present a simulation using our proposed method and check the feasibility. This shows that proposed method is better than existing methods in terms of the optimality of the trajectory and the satisfaction of the kinematic constraints.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.4
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• pp.110-126
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• 2024

Several studies have focused on developing the safest and most efficient path from the current location to the available parking area for vehicles entering a parking lot. In the present study, the parking lot structure and parking environment such as the lane width, width, and length of the parking space, were vaired by referring to the actual parking lot with vertical and horizontal parking. An automatic parking path planning model was proposed by collecting path data by various setting angles and environments such as a starting point and an arrival point, by putting the collected data into a deep learning model. The existing algorithm(Hybrid A-star, Reeds-Shepp Curve) and the deep learning model generate similar paths without colliding with obstacles. The distance and the consumption time were reduced by 0.59% and 0.61%, respectively, resulting in more efficient paths. The switching point could be decreased from 1.3 to 1.2 to reduce driver fatigue by maximizing straight and backward movement. Finally, the path generation time is reduced by 42.76%, enabling efficient and rapid path generation, which can be used to create a path plan for autonomous parking during autonomous driving in the future, and it is expected to be used to create a path for parking robots that move according to vehicle construction.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.1722-1727
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• 2006

배달할 우편물을 경로에 따라 자동 정렬하는 순로구분기의 연구개발이 완료단계에 있어 이를 현장에 도입하고자 하는 계획이 수립되고 있다. 순로구분기는 우편물 영상 처리, 한글주소 인식, 코드 부여, 구분기 제어 등의 기능이 복합되어 작동되며, 구분 성공률에 따라 자동 순로구분 작업 이후의 추가 수작업의 양이 달라진다. 본 연구에서는 수작업 처리를 고려하여 자동화 효과를 개선하기 위한 방안을 전체 작업소요시간을 중심으로 제시하고 각 방안의 장단점을 비교한다. 먼저 자동화기기를 도입했을 때의 순로구분 작업을 분석한 후, 주소 인식 성능을 보완하는 비디오코딩 작업을 포함하는 경우와 배달점 소그룹까지만 구분(중구분)하는 경우에 대해 분석하여 비교한다. 분석 결과는 향후 순로구분기 도입시의 운영 효과를 높이기 위한 실행방안을 마련할 때 활용될 것이다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.4D
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• pp.433-442
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• 2010

Recent decrease in the availability of experienced skilled labor and a corresponding lack of new entrants has required the need for automating many of the construction equipment used in the construction industry. In particular, excavators are widely used throughout earthwork operations and automating its tasks enables work to be performed with higher productivity and safety. This paper introduces an optimal path generation method which is one of the core technologies required to make "Intelligent" excavators a reality. The method divides a given earthwork area into unit cells, identifies networks created by linking these cells, and identifies the optimal path an excavator should follow to minimize its total transportation costs. In addition, the method also accounts for drainage direction and path continuity to ensure that the generated path considers site specific conditions.

• Current Industrial and Technological Trends in Aerospace
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• v.4 no.2
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• pp.55-67
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• 2006

20세기에 탄생한 동력비행기는 인간의 이동능력을 비약적으로 향상시켰다. 인류의 미개척지였던 항공분야의 발전은 지속적인 기술개발을 통해 더 빨리, 더 멀리, 더 높이 향하기 위해서 계속 나아가고 있다. 이러한와중에 최근에 괄목할 만한 성장을 이룬 컴퓨터와 소프트웨어 산업의 발전은 비행임무에 따라 위험성이 높거나, 사람이 하기 힘든 반복적이고 지루한 비행을 대신하기위한 로봇 비행체 즉, 무인항공기의 개발을 가능하게 하였다. 무인항공기의 탄생 초기에는 조종사의 희생을 줄이기 위해 군사 분야에서 주로 사용되었으나, 산림감시나 해안정찰, 기상관측, 재난관측, 조난자 수색 등 민수분야의 임무로 점차 활동영역이 넓혀지고 있다. 현재 무인항공기에 탑재된 인공지능의 수준은 안정된 비행이 가능하도록 하는 자동조종(autopilot)과 주어진 비행경로를 추종하기위한 항법유도(Navigation & Guidance)정도이며, 비행 중 발생하는 비상상황에 대처하기 위한 의사판단은 지상의 조종자에 의해 결정된다. 앞으로는 계획되지 않은 상황을 맞이했을 때 무인기 스스로 판단하여 경로를 변경하고, 동시에 여러 무인기들과 협력하여 임무를 수행함으로써 임무효율을 높이는 방향으로 인공지능의 수준이 향상될 것이다. 본 논문에서는 최근의 무인항공기 개발추세와 이들 무인기에 고려되고 있는 제어기에 대해 살펴보고, 향후 무인항공기에 적용될 자율비행 알고리듬과 제어기 시스템의 개발동향에 대해 고찰하였다.