• Transactions of The Korea Fluid Power Systems Society
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• v.3 no.3
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• pp.20-24
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• 2006

Air balancer is a conveyance cargo-handling machine, used in assembly and process lines of car and machining industries. This can lift up an object, the weight of which is from 5 to 200 kg, and moves it to a position. As industrial technologies evolve, it is required to move an object and fit it into a specified position with greater accuracy, rather than performing simple tasks such as lifting objects up and down as conventional ones do. There is also a demand to handle an object with one hand, rather than with two hands,. Through designs of manifold unit for an air balancer function, pilot regulator unit to keep pressure constant, hand unit for an accurate load perception function, and air balancer circuit, this study enables everybody to work it with ease and convenience. Experiments and comparisons were conducted for the performance evaluation of the circuit.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1996.04a
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• pp.108-116
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• 1996

본 논문에서는 하중부와 방법을 추(dead weight)와 공압(pneumatic)을 이용한 방법에서 스프링을 이용한 방법을 추가하였으며, 압축형 스프링을 선택적으로 사용하여 마찰시험기 수직방향에서의 강성을 큰 변화 폭으로 변화시켰다. 또한 선행된 연구를 통하여 수직하중의 변동량에 크게 영향을 미치는 것으로 알려진 바 있는 디스크 시편의 misaligment 효과를 상사하고 극대화 하기 위하여 본 논문에서는 경사진 디스크 시편을 추가로 사용하였다. 상기조건으로 마찰시험기 시스템의 각 하중부과 방법과 수직강성 변화가 마찰특성에 미치는 영향을 실험적으로 측정 평가하였으며, 마찰시험기 동특성계 모델의 이론적 해석을 통하여 마찰특성 변화를 고찰하였다. 또한, 미끄럼 접촉 시의 수직력과 마찰력을 측정하고, 데이터의 통계적 처리방법에 따른 마찰계수의 변화 특성도 평가하였다.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.54 no.1
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• pp.73-80
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• 2018

Intermittent duty of emergency generator has problems emitting large quantities of PM and NOx in exhaust gas. The aim of this study is to propose DPF system which can be applied to medium-large emergency generators. The system is composed of soot dust collector, silencer and filter trap, which is designed to reduce PM emissions at the emergency generator start-up. The pneumatic system controls a flow direction of exhaust gas to pass through the soot collector and filter trap until the engine reaches complete combustion condition. An experiment is performed to measure PM content and concentration to analyze the performance and characteristics of the proposed system.

• The monthly packaging world
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• s.259
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• pp.70-75
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• 2014

한국식품연구원(원장 권대영) 유통시스템연구단 박형우 박사 연구팀은 내수가 포화된 우리포장산업계의 신규시장 개척을 위해 태국의 포장산업 현황을 분석, 조사한 결과를 바탕으로 우리 포장업계의 신(新)시장 개척 및 해외수출을 위한 중요한 정보를 국내 최초로 조사, 분석 하였다고 밝혔다. 연구팀은 자료 조사를 위해 태국 카세사트 대학 포장학과와 2012년 하반기 부터 1년간 태국의 포장협회, 수출입협회, 관련 국가기관 등을 통해 조사하였다. 태국의 포장산업은 폴리올레핀 등 단순 포장재를 주로 생산하며 EVOH 등 고차단 재료, 다층 공압출 필름, Al. 메탈라이징, 냉동포장 분야는 아직 미진한 것으로 나타나 이런 분야에 강점을 가진 우리 포장 업계가 태국 3조원대의 포장산업 시장으로 지경을 넓혀 가는데 중요한 자료로 활용될 수 있을 것이라고 기대하였다. 한국식품연구원 박형우 박사는 "이번 연구 결과는 태국의 포장산업 현황을 조사한 결과로 고차단성, 고품질의 포장재를 필요로 하는 태국 포장재 시장 진출에 필요한 중요한 기초자료로 사용되어 수출증대에 큰 파급효과를 가져올 것"이라고 하였다. 본 고에서는 태국의 포장산업 개요와 특징에 대해 살펴보도록 한다.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.10
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• pp.137-146
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• 2004

This is the second of two companion papers concerned with the analysis and design of a pneumatic vibration isolation system. The properties of the system are clarified by observation of the transmissibility surface calculated by the models and algorithm developed in the first paper of this research. It Is shown that the nonlinear model proposed in this research is more closer to experimental results than the linear model that have been used in previous studies. The design optimization of the major design variables that affect the performance of the system is achieved by using the condition for attenuation, disturbance rejection and maximum damping in resonance peak. The design space search method is adopted for the optimization of the orifice area. The models, transmissibility calculation algorithms and design optimization techniques developed in this research are shown to be greatly helpful to the optimal design of the pneumatic vibration isolation system by experiment.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.1
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• pp.109-116
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• 1998

This paper is concerned with effective operating method of pneumatic on-off valves for improving position control accuracy, valve life-time and position settling time using modified pulse width modulation with dead-zone (MPWMD). The pneumatic system using on-off valves has advantage of simple construction and low cost compared with a system with servo-valves. The performance of the proposed control method is investigated experimentally for the position control of a pneumatic cylinder using on-off valves. Experimental results show that the proposed algorithm for valve operation can be used to obtain fast and accurate position control compared to the conventional PWMD algorithm. It is also shown that the use of the proposed MPWMD algorithm for the position control significantly reduces the number of valve switching and noise.

• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.5
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• pp.397-406
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• 2003

Resistance spot welding is widely employed in a manufacturing process. In recent years, the requirement for more sophisticated quality control procedures has been in mass production industries. The requirements for high productivity and better weld qualities have lead to the development of more widely available microcomputer-based control. In this study, the inverter type power source and welding servo gun are developed. As the results, we have some advantages over the previous methods such as pneumatic gun. One of them is that the precise pressure control can be attained during the welding process. In addition, production time and cost can be decreased.

• Journal of Biosystems Engineering
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• v.25 no.1
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• pp.63-70
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• 2000

In Korea, researches for year-round leaf vegetables production system are in progress and the most of them are focused on environment control. Automation technologies for harvesting , transporting and grading need to be developed. This study was conducted to develop harvesting process automation system profitable to a competitive price. 1. Manipulator and end-effector are to be designed and fabricated , and fuzzy logic controller for controlling these are to be composed. 2. The entire system constructed is to be evaluated through a performance test. A robot system for harvesting a lettuce was developed. It was composed of a manipulator with 20DOF (degrees of freedom) an end-effector, a lettuce feeding conveyor , an air blower , a machine vision device, 6 photoelectric sensors and a fuzzy logic controller. A fuzzy logic control was applied to determined appropriate grip force on lettuce. Leaf area index and height index were used as input parameters, and voltage was used as output parameter for the fuzzy logic controller . Success rate of the lettuce harvesting system was 93.06% , and average harvesting time was about 5 seconds per lettuce.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.33-34
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• 2006

The most bottleneck of development of automation excavator system is the making mathematical linear model. Because of non-linear of control circuit, cylinder, join in hydraulic circuit, and heavy loading so on. Therefore, whatever robust controller is designed, real experimentation is necessary. But, a real experimentation has many risks. The excavator is expensive and large size. Therefore a development of experimentation system is difficult and not safe. Specially, there have a difficulty, because of big noise. So, on experimentation is difficult in school. Manufacturing pneumatic excavator modeland using system identification, design a system transfer function in this paper. Also, planning m-PID Controller using CDM, and examining usefulness applied to actuality model.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.820-825
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• 1996

This paper is concerned with effective operating method of pneumatic on-off valves for improving position control accuracy, valve life-time and position settling time using modified pulse width modulation with dead-zone. The pneumatic system using on-off valves studied in this paper has advantage of simple construction and low cost compared with a system with servo-valves. The performance of proposed control system is investigated experimentally for the position control of a pneumatic cylinder using on-off valves. Experimental results show that the proposed algorithm for valve operation can be used to obtain fast and accurate position control and to prevent on-off valves from unnecessary switching.