• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.821-825
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• 1991

This paper presents an architecture and control logic of a Flexible Manufacturing Cell (FMC) which is one of the important elements under Computer Integrated Manufacturing (CIM) environment. To implement FMC, it is very important to develop a software which can control and monitor the overall system in an integrated environment. Our primary concern in this research is not to develop individual systems, but to integrate them in the hierarchical control level. Progress on the research of integrating CAD/CAM, Process Planning, Off-line Robot Programming and Simulation module into FMC control system is reported. FMC hardware system used here has an Automated Storage & Retrieval System (AS/RS), a conveyor system, a transfer robot, a CNC milling machine, a bar-code system, and an IBM PC/AT as Cell Control System (CCS). In order to demonstrate the operational result, the name plates, text-carved aluminium plates, are manufactured by this system.

• Proceedings of the Korea Society for Simulation Conference
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• 1999.10a
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• pp.217-217
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• 1999

The main objective of this study is to simulate the design and operational policies of the assembly shop of an automotive plant for planning purposes and to find possible improvements. The simulation study was used to answer the following questions: How does the sequence affect the daily throughput\ulcorner What are the bottlenecks to the assembly lines in a given scenario\ulcorner A Simulation model was developed in accordance with the objective of this study. The model incorporates detailed workstation logic to accurately model downtime results through the use of a pull cord system. It is written with SIMAN. The discrete event feature of SIMAN does not adequately model the conveyor systems of the asembly shop. As a result, a few subroutines were added to the SIMAN modeling structures to mimic the operations of the assembly shop. Use of the model uncovered attractive improvement opportunities, such as a tremendous gain in annual volume if four additional spaces were added to a between-line buffer.

• Journal of the Ergonomics Society of Korea
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• v.24 no.2
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• pp.57-63
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• 2005

Ergonomic intervention techniques were adopted to assess and control potential risk factors of work-related musculoskeletal disorders(WMSDs) in the automated light assembly manufacturing system. Ten different kinds of assembly workstations implemented with a conveyor system and twelve female workers were observed and evaluated with careful video film analysis. Several close examinations using sets of checklists established by qualified safety and health organizations, such as NIOSH, OSHA, and ANSI, were conducted and every workers and staffs in the site participated in the self-report questionnaires and off-line interviews. Typical risk factors and symptoms of the upper extremity musculoskeletal disorders were found and categorized into specific parts of body. To reduce risk factors of WMSDs and improve system productivity new revised workstation standards, physical dimensions, were suggested accordant with anthropometric characteristics of workers and a heuristic decision strategy of rotating shift work schedules according to work contents has proposed to mitigate cumulative physical stress. Finally, ergonomic programs of entire company to prevent WMSDs were structured.

• Journal of Korean Institute of Industrial Engineers
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• v.12 no.1
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• pp.119-131
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• 1986

Described in this paper is a modelling methodology for mass production system simulation. The mass production system under consideration consists of various types of flow lines, special purpose production facilities, conveyor lines, palletized carts, and storage facilities. This type of production system is typical in home appliance industry, automobile industry, footwear industry, etc. where a variety of product mix are mass-produced. The modelling methodology is based on the "discrete-event formalism", and an "activity-oriented world view" is adopted to formalize the system description. A distinctive feature of the modelling methodology is that only the static structure (ie, system components) is included in the fixed model. The dynamic structure of the system is specified through a "data-driven" mechanism, which is an extension of the "experimental frame" concept. Each type of system components (ie, flow line, conveyors, carts, etc.) is formally modeled by using Activity Cycle Diagrams. The issue of "model structuring" is also addressed. The modeling methodology has been successfully applied in a real simulation study of a mass production system.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.5
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• pp.435-442
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• 2014

This paper describes an improved design model that can be used to configure a non-contact pneumatic device to turn a large sheet at the in-line system. For rotational moving in the conveyor system, the conventional method is to turn the system itself. The improved non-contact pick-up system mainly uses 8 pairs of L-shaped latches and 12 swirl type heads. It is positioned above the upward air flow table. This system performs the non-contact gripping and side-edge contact support in the vertical and rotational directions to hold the self-weight of a large flat sheet. A non-contact air head can exert a sufficient gripping ability at 4N lower than the standard working pressure. The side latches support 60% of the lifting force required. Through structural and flow analysis, the working conditions were simultaneously considered in accordance with the deflection and flatness of the glass.

• IE interfaces
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• v.18 no.2
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• pp.136-147
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• 2005

This paper introduces a simulation study regarding the operation of the Painted Body Storage (PBS) in an automobile factory. In the paint shop of the factory, same colored bodies are grouped together in order to increase the effectiveness of process, for example decrease the loss of cleaning the painting-gun when the color of body changes from one to another. However the production of automobiles in the assembly shop is a typical example of the mixed model assembly production. Therefore PBS locates between the paint shop and the assembly shop for control the input sequence of bodies to the assembly shop, and it enables to meet the smoothing requirement of assembly sequence. There are highly restricted constraints on the assembly sequence in a assembly shop. Those are spacing restriction and smoothing restriction. If such restrictions are violated, conveyor-stop or utility work will be necessary. Thus the major objective of PBS is to control the assembly sequence in a way to meet the two restrictions. In this paper a case study of PBS in an automotive factory is introduced. The storage/retrieval algorithms are suggested and the proposed system is verified using simulation models. Sensitivity analysis for operating factors is also conducted.

• The Transactions of the Korean Institute of Power Electronics
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• v.20 no.5
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• pp.456-463
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• 2015

Nowadays, small quantity batch production, which is so-called a flexible manufacturing system, is a major trend in the modern factory automation industry. The demands for new transportation system are increased gradually, with which multiple passive carriers carrying materials and semi-products are precisely and individually controlled along a single closed rail. Thus, a new type of permanent magnet linear synchronous motor (PMLSM), which consists of state coils on a single rail and PM movers as many as carriers, is proposed in this paper. The rail can be segmented as modules with pairs of coils and a current amplifier, which makes the transportation system simple; therefore, the rail can be easily extended and repaired. A design method of the new PMLSM with a single carrier is proposed, which can be thought as a new version of PMLSM, a coil-segmented coreless PMLSM (CS-CLPMLSM). Experimental setup for it is made, and propulsion results show that with the help of a new effective coil selection and switching algorithms, the conventional current-based vector control is sufficient to fulfill the position and velocity control of the new PMLSM. The proposed PMLSM is expected to fulfill seamless servo-control of multiple carriers also in process line, such as a new generation of flat panel display manufacturing line.

• Korean Journal of Poultry Science
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• v.50 no.1
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• pp.23-30
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• 2023

This study was conducted to analyze the correlation between egg breakage rate and cumulative external forces on eggs during the egg transfer system in 12 commercial layers farms. The commercially available electronic egg device was used to detect the external forces on eggs during egg collection systems. In addition, egg breakage rate per farm was collected. It was found that the external force on eggs were greater in the order of washer and dryer connection part, conveyor connection part, transfer, sorter, collecting elevator, packer, egg transfer connection part, and egg tray. A positive relationship between the external forces on eggs during egg transit system and the incidence of cracked eggs per farm was noted. The external forces on eggs varied from 5G to 38G depending on the location and the egg breakage rate ranged from 3.2 to 14.5% per farm. Although efforts to produce eggs with high eggshell quality are considered important, extra care should be made to lower the external forces on eggs during the egg transfer system from laying house to egg packing center.

• The KIPS Transactions:PartD
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• v.9D no.5
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• pp.915-924
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• 2002

Conventional Systems for parcel sorting consist of two sequences as loading the parcel into conveyor belt system and post-code input. Using bar code information, the parcels to be recorded and managed are recognized. This paper describes a 32 $\times$ 32 sized mini-block inspection to extract bar code Region of Interest (ROI) from the line Charged Coupled Device (CCD) camera capturing image of moving parcel at 2m/sec speed. Firstly, the Min-Max distribution of the mini-block has been applied to discard the background of parcel and region of conveying belts from the image. Secondly, the diagonal inspection has been used for the extraction of letters and bar code region. Five horizontal line scanning detects the number of edges and sizes and ROI has been acquired from the detection. The wrong detected area has been deleted by the comparison of group size from labeling processes. To correct excluded bar code region in mini-block processes and for analysis of bar code information, the extracted ROI 8 boundary points and decline distribution have been used with central axis line adjustment. The ROI extraction and central axis creation have become enable within 60～80msec, and the accuracy has been accomplished over 99.44 percentage.

• Agricultural and Biosystems Engineering
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• v.4 no.1
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• pp.8-15
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• 2003

In Korea, quality evaluation of dried oak mushrooms are done first by classifying them into more than 10 different categories based on the state of opening of the cap, surface pattern, and colors. And mushrooms of each category are further classified into 3 or 4 groups based on its shape and size, resulting into total 30 to 40 different grades. Quality evaluation and sorting based on the external visual features are usually done manually. Since visual features of mushroom affecting quality grades are distributed over the entire surface of the mushroom, both front (cap) and back (stem and gill) surfaces should be inspected thoroughly. In fact, it is almost impossible for human to inspect every mushroom, especially when they are fed continuously via conveyor. In this paper, considering real time on-line system implementation, image processing algorithms utilizing artificial neural network have been developed for the quality grading of a mushroom. The neural network based image processing utilized the raw gray value image of fed mushrooms captured by the camera without any complex image processing such as feature enhancement and extraction to identify the feeding state and to grade the quality of a mushroom. Developed algorithms were implemented to the prototype on-line grading and sorting system. The prototype was developed to simplify the system requirement and the overall mechanism. The system was composed of automatic devices for mushroom feeding and handling, a set of computer vision system with lighting chamber, one chip microprocessor based controller, and pneumatic actuators. The proposed grading scheme was tested using the prototype. Network training for the feeding state recognition and grading was done using static images. 200 samples (20 grade levels and 10 per each grade) were used for training. 300 samples (20 grade levels and 15 per each grade) were used to validate the trained network. By changing orientation of each sample, 600 data sets were made for the test and the trained network showed around 91 % of the grading accuracy. Though image processing itself required approximately less than 0.3 second depending on a mushroom, because of the actuating device and control response, average 0.6 to 0.7 second was required for grading and sorting of a mushroom resulting into the processing capability of 5,000/hr to 6,000/hr.