• Journal of information and communication convergence engineering
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• 제11권4호
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• pp.274-281
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• 2013

In this study, we consider the challenges in motion planning for automated driving systems. Most of the existing online motion-planning algorithms, which take dynamics into account, find it difficult to operate in an environment with narrow passages. Some of the existing algorithms overcome this by offline preprocessing if environment is known. In this work an online algorithm for motion planning with dynamics in an unknown cluttered environment with narrow passages is presented. It utilizes an idea of hybrid planning with sampling- and discretization-based motion planners, which run simultaneously in a full configuration space and a derived reduced space. The proposed algorithm has been implemented and tested with a real autonomous vehicle. It provides significant improvements in computational time performance over basic planning algorithms and allows the generation of smoother paths than those generated by the recently developed hybrid motion planners.

• 국제학술발표논문집
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• The 8th International Conference on Construction Engineering and Project Management
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• pp.41-49
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• 2020

Concurrent construction offers considerable improvement for shorten the project duration of its production process. Therefore, standardized concurrent construction is widely applied in building construction projects. However, resources planning for standardized concurrent construction project is manually developed by construction manager. This practice is not effective since it is time-consuming and error-prone for managers to identify all project-specific information, distinguish different activity-resource types, interpret these types and analyze how they affect resource allocated on an ad hoc basis. Therefore, this research investigates the opportunity for leveraging activity modeling to enable automated resource planning for standardized concurrent construction during project development, with identifying the characteristics of construction activities under standardized concurrent planning and determining the activity-resources types that affects resource planning. Both will function as a basis for modeling these construction activities in a computer-interpretable manner and for automation in resource planning.

• 산업공학
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• 제2권1호
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• pp.37-45
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• 1989

Guide path design is the most important factor in planning automated guided vehicle systems(AGVS) in manufacturing shop environments. This paper studies a heuristic procedure to design an optimal bi-directional guide path with the objective of the minimum total travel time of the vehicles. An example is solved to validate the procedure developed.

• 한국정밀공학회지
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• 제19권1호
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• pp.107-118
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• 2002

This paper deals with an automated computer-aided process planning and die design system by which designer can determine operation sequences even if they have a little experience in process planning and die design of quasi-axisymmetric cold forging product by cold former working. The approach to the system is based on knowledge-based rules and a process knowledge base consisting of design rules is built. Knowledge for the system is formulated from plasticity theories, empirical results and the empirical knowledge of field experts. Programs for the system have been written in AutoLISP for the AutoCAD using a personal computer. An attempt is made to link programs incorporating a number of expert design rules with the process variables obtained by commercial FEM softwares, DEFORM and ANSYS, to form a useful package. The system is composed of three main modules and five sub-modules. The process planning and die design module considers several factors, such as the complexities of preform geometry, punch and die profiles, specifications of available cold farmer, and the availability of standard parts. As the system using 2D geometry recognition is integrated with the technology of process planning, die design, and CAE analysis, the standardization of die parts for wheel bolt requiring cold forging process is possible. The developed system makes it possible to design and manufacture quasi-axisymmetric cold forging product more efficiently.

• 한국정밀공학회지
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• 제20권4호
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• pp.29-38
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• 2003

This paper deals with an automated computer-aided process planning and die design system with which designer can determine operation sequences even after only a little experience in process planning and die design of multi former-bolt products by multi-stage former working. The approach is based on knowledge-based rules, and a process knowledge base consisting of design rules is built. Knowledge fur the system is formulated from plasticity theories, empirical results and the empirical knowledge of field experts. Programs for the system have been written in AutoLISP for AutoCAD with a personal computer. An attempt is made to link programs incorporating a number of expert design rules with the process variables obtained by commercial FEM softwares, DEFORM and ANSYS, to form a useful package. The system is composed of four main modules. The process planning and die design module considers several factors, such as the complexities of preform geometry, punch and die profiles, specifications of available multi former, and the availability of standard parts. It can provide a flexible process based on either the reduction in the number of forming sequences by combining the possible two processes in sequence, or the reduction of deviation of the distribution and the level of the required forming loads by controlling the forming ratios. The system uses 2D geometry recognition and is integrated with the technology of process planning, die design, and CAE analysis. The standardization of die parts for multi former-bolt products requiring a cold forging process is described. The system developed makes it possible to design and manufacture multi former-bolt products more efficiently.

• 한국전자통신학회논문지
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• 제17권1호
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• pp.187-192
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• 2022

현재 컨테이너 항만은 최신의 정보통신 기술을 활용한 자동화된 운영시스템에 의해 규격화된 컨테이너들은 최적의 적부계획(Stowage Planning)에 의해 체계적으로 이루어지고 있다. 그러나 단위 중량이 수십 톤에 이르는 철강 코일의 적부는 현재까지도 수작업으로 이루어지고 있어서 작업이 매우 비효율적이다. 그 결과로 작업들은 지연되고 안전사고들도 자주 발생되고 있다. 본 연구에서는 수작업에 의한 철강코일의 적부 과정에서 일어나는 판단착오, 체선, 안전사고 등을 방지하기 위하여 철강코일 적부 자동화 시뮬레이션 시스템을 설계하였다.

• 자동차안전학회지
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• 제15권4호
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• pp.16-22
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• 2023

This paper presents a proactive longitudinal motion planning algorithm for improving the safety of an automated bus. Since the field of view (FOV) of the autonomous vehicle was limited depending on onboard sensors' performance and surrounding environments, it was necessary to implement vehicle-to-vehicle (V2V) communication for overcoming the limitation. After a virtual V2V-equipped target was constructed considering information obtained from V2V communication, the reference motion of the ego vehicle was determined by considering the state of both the V2V-equipped target and the sensor-detected target. Model predictive control (MPC) was implemented to calculate the optimal motion considering the reference motion and the chance constraint, which was deduced from manual driving data. The improvement in driving safety was confirmed through vehicle tests along actual urban roads.

• 한국ITS학회 논문지
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• 제19권1호
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• pp.107-120
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• 2020

본 연구는 한국형 자율주행자동차 윤리 가이드라인 제정에 앞서, 제안된 윤리 가이드라인 초안을 구성하는 항목에 대한 중요도를 확인하고자 핵심 요소와 세부항목에 대한 설문조사 결과를 활용하여 계층화 분석을 수행하였다. 분석 결과, 인간의 존엄성과 생명을 최우선으로 보장해야함을 내포한 문항의 중요도가 높게 평가되었으며, 사고 발생을 미연에 방지하고 사고가 발생하였을 때 차량 이용자의 책임이 있어야한다는 중요도가 높게 평가되었다. 그러나 정부부처 및 관리자의 역할에 대해서는 중요도가 낮게 평가되었는데, 이는 법적 규제를 통한 무조건적인 규제 대신 개인의 영역을 존중하고 공공의 이익을 동시에 향유할 수 있는 방안을 도출할 필요가 있다는 의견으로 사료된다. 향후 자율주행자동차의 윤리 가이드라인의 제정을 위해서는 지속적인 의견수렴 및 항목의 보완과 함께 관련 교육 및 세미나 등을 통해 사회적 수용성을 확보할 수 있는 방안을 강구해야 할 것으로 판단된다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.591-594
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• 2002

Generating NC-code from 3D part model needs a lot of effort to make many decisions, including machining area, tool change data, tool data, cutting condition, etc., by using either manual or computer aided method. This effort can be reduced by integration of automated process planning and NC-code generation. In case of generating NC code with a help of the process planning system, many data mentioned from the process planning can be used. It means that we can create NC-code about a full part. In this study, integration of FAPPS(Feature based Automatic Process Planning) with a NC-code generating module is described and additional data to adapt NC-code for machine shop is discussed.

• 한국의학물리학회지:의학물리
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• 제20권3호
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• pp.180-190
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• 2009

전립선암의 위치는 방사선 치료도중 변하는 경우가 많으며 이는 종양선량을 낮추고 정상조직선량이 높아질 수 있다. 이 논문의 목적은 방사선 치료중에 전립선암의 위치 및 깊이 변화를 자동적으로 감지하는 시스템을 개발하고 이를 적용해 환자의 국부에 조사되는 방사선량의 변화를 최소화 하는 데 있다. 이 연구에서는 10명의 환자로부터 38장의 영상자료를 통해 수행되었으며 전립선암에 부착된 금-표지자를 이용해 종양의 질량중심을 구하고 이를 기반으로 종양의 위치변화를 감지하였다. 전립선암의 평균적인 위치변화는 좌우와 위아래로 각각 0.9 mm와 2.3 mm이었으며 최고 위치변화는 각 각 3.3 mm와 7.2 mm였다. 일상적으로 전립선암의 양성자치료에 많이 사용되는 마주보는 두 개의 양성자빔(bilateral beam configuration) 조건에서 좌우의 위치변화는 깊이 변화를 의미하며 이는 약 0.7 mm에서 3.3 mm까지 변화하고 있음을 알 수 있었다. 실험결과 종양의 깊이 변화가 1 mm, 2 mm 그리고 3 mm 보다 많이 차이 나는 경우가 각각 42.1%, 26.3% 그리고 2.6%로 나타났다. 이러한 결과를 토대로 봤을 때 양성자치료에서 자동적으로 종양의 깊이 변화를 분석하는 것이 가능하다는 것을 알 수 있었으며 이를 이용한다면 종양선량을 높이고 정상조직선량을 낮추어 치료효과를 높일 수 있다.