• 한국산업융합학회 논문집
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• 제4권2호
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• pp.141-147
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• 2001

This paper presents a developing algorithm of checking errors of feed mechanism in the NC machine tool with DAC method. It is useful to check static and dynamic rigidity with relation between lost motion and current of rotor. For checking error of feed in assembly tuning with machining center proposed checking algorithm is useful.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.52.2-52
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• 2001

We propose a new optimization method to improve the productivity of dispenser machines in PCB assembly lines. The optimization problem for multi-nozzle dispensers is formulated as a variant TSP. A genetic algorithm is applied to the problem to get a near-optimal solution. Chromosome and some operator are newly defined to implement the genetic algorithm for multi-nozzle dispensers. Simulation results are then presented to verify the usefulness of the method.

• 한국컴퓨터정보학회논문지
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• 제19권5호
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• pp.89-98
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• 2014

본 논문은 NP-난제 문제로 알려진 단일모델 단방향 조립라인 균형문제에 대해 휴리스틱 알고리즘을 제안하였다. 조립라인 균형문제는 주로 메타휴리스틱 방법들을 적용하고 있는 추세이다. 제안된 알고리즘은 최종제품이 생산될 때까지 가장 많은 공정으로 조립되는 경로를 주경로로 설정하고, 주경로를 따라가면서 각 작업자에게 순환시간 조건을 만족하는 작업량을 배정하는 군집화 알고리즘을 제안하였다. 제안된 알고리즘은 최소의 작업자수를 결정하고, 순환시간도 단축시키는 결과를 얻었다. 9개의 다양한 실험 데이터에 제안된 주경로 군집화 휴리스틱 알고리즘을 적용한 결과 메타휴리스틱 방법들에 비해 보다 좋은 성능을 갖고 있음을 보였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.719-723
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• 1997

The welding automation in ship manufacturing process,especially in the sub-assembly line is considered to be a difficult job because the welding part is too huge, various, unstructured for a welding robot to weld fully automatically. The weld orocess at the sub-assembly line for ship manufacturing is to joint the various stiffener on the base panel. In order to realize automatic robot weld in sub-assembly line, robot have to equip with the sensing system to recognize the position of the parts. In this research,we developed a vision system to detect the position of base panle for sub-assembly line is shipbuilding process. The vision system is composed of one CCD camera attached on the base of robot, 2-500W halogen lamps for active illumination. In the image processing algorithm,the base panel is represented by two set of lines located at its two corner through hough transform. However, the various noise line caused by highlight,scratches and stiffener,roller in conveyor, and so on is contained in the captured image, this nosie can be eliminated by region segmentation and threshold in hough transform domain. The matching process to recognize the position of weld panel is executed by finding patterns in the Hough transformed domain. The sets of experiments performed in the sub-assembly line show the effectiveness of the proposed algorithm.

• Industrial Engineering and Management Systems
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• 제12권4호
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• pp.330-335
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• 2013

A surface mount device (SMD) assembles electronic components on printed circuit boards (PCB). Since a component assembly process is a bottleneck process in a PCB assembly line, making an efficient SMD plan is critical in increasing the PCB assembly line productivity. Feeder assignment is an important part of the SMD plan optimization. In this paper, we propose a feeder re-assign improvement algorithm for a specific type of SMD machine with a piano type multi-head gantry. Computational results on some real-world benchmark data sets show the effectiveness of our proposed algorithm.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 추계학술대회 논문집
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• pp.187-192
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• 2001

In this paper, a practical method to generate task strategies applicable to charmfulness and high-precision assembly, is proposed. The difficulties in devising reliable assembly strategies result form various forms of uncertainty such as imperfect knowledge on the parts being assembled and functional limitations of the assembly devices. In approach to cope with these problems, the robot is provided with the capability of learning the corrective motion in response to the force signal through iterative task execution. The strategy is realized by adopting a learning algorithm and represented in a binary tree type database. To verify the effectiveness of the proposed algorithm, a series of simulations and experiments are carried out under assimilated real production environments. The results show that the sensory signal-to-robot action mapping can be acquired effectively and, consequently, the assembly task can be performed successfully.

• 산업경영시스템학회지
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• 제29권4호
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• pp.34-42
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• 2006

This paper considers an assembly-type flowshop scheduling problem in which each job is assembled with two types of components. One type of the components is outsourced with positive lead time but the other type is fabricated in-house at the first stage. The two types of the components should be prepared at the first stage before starting the assembly operation for each job at the second stage. The objective is to schedule the jobs so that the makespan is minimized. Some solution properties and lower bounds are derived and incorporated into a branch and bound algorithm. Also, an efficient heuristic is developed. The performances of the proposed branch and bound algorithm and heuristic are evaluated through computational experiments.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2004년도 춘계공동학술대회 논문집
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• pp.425-428
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• 2004

Flexible assembly line (FAL) is a production system that assembles various parts in unidirectional flow line with many constraints and manufacturing flexibilities. In this research we deal with a FAL balancing problem with the objective of minimizing the maximum workload allocated to the stations. However, almost all the existing researches do not appropriately consider various constraints due to the problem complexity. Therefore, this thesis addresses a balancing problem of FAL with many constraints and manufacturing flexibilities, unlike the previous researches. To solve this problem we use a genetic algorithm (GA). To apply GA to FAL, we suggest a genetic representation suitable for FAL balancing and devise evaluation method for individual's fitness and genetic operators specific to the problem, including efficient repair method for preserving solution feasibility. The experimental results are reported.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1237-1240
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• 1996

This paper proposes a heuristic algorithm for performing the line balancing of PCB assembly fine including multiple surface mounters efficiently. We consider a PCB assembly line including the multiple surface mounters arranged serially as a target system. We assume that the number of heads of surface mounters can be changed. Also, the conveyor is assumed to move at a constant speed and have no buffer. Considering the minimum number of machines required for the desired production rate is a discrete nonincreasing function which is inversely proportional to the cycle time, we propose an optimization algorithm for line balancing by using the binary search method. Also we propose an head-changing algorithm. The algorithms are validated through the computer simulation.

• 대한조선학회논문집
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• 제46권6호
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• pp.622-630
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• 2009

This paper deals with the automation techniques of ship assembly drawing generation, which help the designer to reduce the man-hour for completing the drawings, and improve the quality of the drawing for the given time. The automation techniques are necessary for the reasons of economical efficiency and improve communication between the designers and shop-makers. The overlap-avoidance algorithm of this paper maximizes the readability of the drawings using the optimization techniques and the heuristic rules, especially for the ship assembly field.