• 산업경영시스템학회지
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• 제21권48호
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• pp.269-277
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• 1998

In this study, a traditional concept of sampling inspection plan for the quality assurance system is extended to a consideration of economic aspects in total production system by representing and analyzing the effects between proceding/succeeding production process including inspection. This approach recognizes that the decision to be made at one manufacturing process (or assembly process) determine not only the cost and the average outgoing quality level of that process but also the input parameters of the cost and the incoming quality to the succeeding process. By analyzing the effects of the average incoming and outgoing quality, manufacturing/assembly quality level and sampling inspection plan on the production system, mathematical models and solution technique to minimize the total production cost for a single product manufacturing system with specified average outgoing quality limit (AOQL) are suggested.

• International Journal of Precision Engineering and Manufacturing
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• 제3권3호
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• pp.50-55
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• 2002

A roller gear cam mechanism is presented. It consists of two or more plate cams with particular teeth, called Conjugate Cam Tooth (CCT) and a turret with axially located rollers. A practical and available configuration has been found out by synthesizing its parameters. The profile equations of the conjugate cam are derived by using a relative velocity method. A program fur the design automation of shape of the conjugate cam and the motion simulation of this kind of mechanism has been deve1oped using the derived formulae with C++ language. Finally, an example is given.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1775-1780
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• 2003

A hybrid finite element analysis was used to analyze the influence of ring gear rim thickness and spline number on the static properties of an epicyclic gear system with manufacturing errors. Both of these parameters affected the bearing force and critical stress. The effect of changes in the rim thickness on the load sharing between the gears depended on the type of manufacturing error. Ring flexibility improved the load sharing between planetary gears only in systems with planet tooth thickness or planet tangential errors; for other types of error, ring flexibility worsened the load sharing. To improve load sharing, rim thickness and spline number should be controlled within a specific range. The effect of the ring gear boundary condition was more apparent in a system with errors than in a normal system.

• 한국산업융합학회 논문집
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• 제24권3호
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• pp.351-361
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• 2021

This study proposes an intelligent control of manufacturing robot with dual arm based on neural network for smart factory implementation. In the control method of robot system, the perspectron structure of single layer based on neural network is useful for simple computation. However, the limitations of computation are emerging in areas that require complex computations. To overcome limitation of complex parameters computation a new intelligent control technology is proposed in this study. The performance is illustrated by simulation and experiments for manufacturing robot dual arm robot with eight axes.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.596-599
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• 2004

The robotic $CO_2$ welding is a manufacturing process to produce high quality joints for metal and it could provide a capability of full automation to enhance productivity. Despite the widespread use in the various manufacturing industries, the full automation of the robotic $CO_2$ welding has not yet been achieved partly because the mathematical model for the process parameters of a given welding task is not fully understood and quantified. Several mathematical models to control welding quality, productivity, microstructure and weld properties in arc welding processes have been studied. However, it is not an easy task to apply them to the various practical situations because the relationship between the process parameters and the bead geometry is non-linear and also they are usually dependent on the specific experimental results. Practically, it is difficult, but important to know how to establish a mathematical model that can predict the result of the actual welding process and how to select the optimum welding condition under a certain constraint. In this research, an attempt has been made to develop an intelligent algorithm to predict the weld geometry (top-bead width, top-bead height, back-bead width and back-bead height) as a function of key process parameters in the robotic $CO_2$welding. To achieve this above objective, Taguchi method was employed using five different process parameters (tip gap, gas flow rate, welding speed, arc current, welding voltage) as a guide for optimization of process parameters.

• 산업경영시스템학회지
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• 제38권3호
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• pp.100-107
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• 2015

Recently as the manufacturers want competitiveness in dynamically changing environment, they are trying a lot of efforts to be efficient with their production systems, which may be achieved by diminishing unplanned operation stops. The operation stops and maintenance cost are known to be significantly decreased by adopting proper maintenance strategy. Therefore, the manufacturers were more getting interested in scheduling of exact maintenance scheduling to keep smooth operation and prevent unexpected stops. In this paper, we proposedan integrated maintenance approach in injection molding manufacturing line. It consists of predictive and preventive maintenance approach. The predictive maintenance uses the statistical process control technique with the real-time data and the preventive maintenance is based on the checking period of machine components or equipment. For the predictive maintenance approach, firstly, we identified components or equipment that are required maintenance, and then machine parameters that are related with the identified components or equipment. Second, we performed regression analysis to select the machine parameters that affect the quality of the manufactured products and are significant to the quality of the products. By this analysis, we can exclude the insignificant parameters from monitoring parameters and focus on the significant parameters. Third, we developed the statistical prediction models for the selected machine parameters. Current models include regression, exponential smoothing and so on. We used these models to decide abnormal patternand to schedule maintenance. Finally, for other components or equipment which is not covered by predictive approach, we adoptedpreventive maintenance approach. To show feasibility we developed an integrated maintenance support system in LabView Watchdog Agent and SQL Server environment and validated our proposed methodology with experimental data.

• 한국재료학회지
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• 제14권1호
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• pp.59-66
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• 2004

In the present study, ceramic brake pads without fiber phases were manufactured by the low temperature heat treatment below$ 700 ^{\circ}C$. The manufacturing parameters of ceramic brake pads and those levels were investigated by the analysis results of signal-to-noise ratios, ANOVA based upon the Taguchi method. The ceramic brake pads prepared in the Mg experiment had a friction coefficient of 0.30～0.55 very close to the target coefficient (0.35～0.45) of commercial brake pads utilized in the automobiles. The frictional properties of ceramic brake pads could be stabilized with the adjustment of amounts of lubricating additives. The optimum preparation conditions as well as batch formulations for the fabrication of non-fibrous ceramic brake pads were finally determined using Taguchi method in this study.

• 한국기계가공학회지
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• 제14권2호
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• pp.59-66
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• 2015

The production of high value-added products requires efficient processing and this constant demand for complex shape processing has led to the need for hybrid processing. In this study, the surface characteristics of hybrid machining, which combines wire-cut E.D.M and vibration, are examined. The selected experimental parameters are verticality, waveform, amplitude, peak current and frequency. The experimental results provide a guideline for selecting reasonable machining parameters. Surface roughness was improved by increasing the amplitude of the vibration.

• 한국기계가공학회지
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• 제15권1호
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• pp.81-88
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• 2016

Recently, high-efficiency machining in the production of high-value products with complex shapes has constantly been required along with the need for hybrid machining. In this study, in addition to wire-cut Electric Discharge Machining (EDM) and vibration, we present the possibility of a hybrid process by carrying out an experiment with aluminum alloy, and the hybrid process determines the nature of the surface. The selected experimental parameters are waveform, amplitude, peak current, and two-dimensional (2D) vibration. The experimental results give the guideline for selecting reasonable machining parameters. The surface roughness was improved about 20% with increases in the amplitude of the vibration.

• 한국생산제조학회지
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• 제6권4호
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• pp.89-95
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• 1997

Welding technique is widely applied to general industry such as pressure vessel for chemical plant, pipe system, heavy industry, and automobile. There are some points which must be considered when robot system is used in welding automation process for productivity improvement. Welding quality is governed by heat input, and this quantity can be different according to shape, property, and thick of material . For desired heat input , weld input parameters such as welding voltage, current, and welding velocity must be determined with those consideration. Until now these parameters have been determined mainly by experience of operator. In this study, the size of welding zone was predicted by fuzzy rules were constructed from the relation between welding variables and weld pool size. Inverse model method which welding control input for welder is determined with optimum voltage and current by fuzzy controller is validatied by computer simulation.