• 산업경영시스템학회지
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• 제18권36호
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• pp.1-11
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• 1995

Manual lifting, as a part of manual materials handling activities, is recognized by authorities in the fields of occupational health and safety as a major hazards to industrial workers. In order to minimize the injuries caused by manual material handling activities as well as maximize job productivity, it is important to determine the maximum weights. This paper presents the optimal combination of membership functions according to the high lifting frequency and determines the safe maximum acceptable weights in manual lifting activities through the actual experiment.

• 한국정밀공학회지
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• 제30권9호
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• pp.909-913
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• 2013

Various types of large substrate handling robots are used in the thin file solar cell manufacturing line as well as LCD or PDP production line. Because the robot handles the heavy substrate at high speed, there are some issues such as vibration control and the optimal design of arms and forks. As the substrate becomes larger and heavier, robot systems are also larger and the vibration issue of the robot end-effector becomes more important. In the paper, we established the robot modeling and the control architecture including the flexible part such as forks. Then, we performed dynamic simulation in the various condition and analyzed the characteristics of the fork vibration. We can reduce the vibration using the trajectory planning and input shaping algorithm and it was proved by experiment.

• 한국생산제조학회지
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• 제25권6호
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• pp.498-503
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• 2016

Many types of robot systems are used in the mass production line of thin film solar cells and flat panel displays. There are some issues such as the deflection and the vibration of the end-effector because robots handle large and heavy substrates at high speed. Heavy payload and high speed cause much vibration because the end-effector (fork) is made of carbon fiber reinforced polymer because of its light weightiness and sufficient stiffness. This study performs a dynamic simulation of an 8.5G solar cell substrate handling robot, including rigid and flexible bodies and a vibration controller. The fifth polynomial trajectory and the zero vibration derivative input shaping algorithm are applied. The vibration reduction is also proved in the experiments.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 추계 학술논문 발표대회
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• pp.170-171
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• 2015

Resource procurement and material handling are considered as a significant part of construction project especially in large or tall building construction site. There are multiple variables that must be considered in a construction site during finishing work such as movement of materials, equipments, and workers. Therefore, it is difficult for construction workers to find the material handling path solely by intuition. The aim of this study is to propose a real-time path finding model suitable for complicated logistics flow in the field. The model explores the optimal transport path of finishing material with its basis on optimization algorithm, and it determines the direction of the Smart Sign. The proposed model is expected to be utilized for planning of efficient finishing material handling.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2275-2278
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• 2005

In this paper, a control algorithm for a servo manipulator is focused on. A servo manipulator system has been developed for remotely handling radioactive materials in a hot cell. It is driven by servo motors. The torque from a servo motor is transferred through a reducer to the corresponding axis. The PID control algorithm is a simple and effective algorithm for such application. However, since friction degrades the algorithm's performance, friction has to be considered and compensated. The major aberrations are the positional tracking errors and the limit cycle. The authors have considered a switching term to a conventional PID algorithm to reduce the friction's effect. It has been tested by a hardware test.

• 한국안전학회지
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• 제14권3호
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• pp.174-180
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• 1999

The objective of this study was to investigate the effects of carrying postures and weight of load carried one time on a worker when carrying heavy loads. Six male students participated in this study to perform a manual materials carrying task as subjects. To make comparison of work loads with physical work capacity, maximal oxygen uptake measurement tests were performed with submaximal test. The average oxygen consumption for the tasks of this study was 27.59~31.93% $VO_2$max. The results showed that the weight of load carried one time affects on working heart rate and oxygen consumption($VO_2$). It was found that the workload was significantly lower when handling a 20kg load at a frequency rate of 3times/min than when handling a 40kg load at a frequency rate of 1.5 times/min. There was no difference between carrying postures. It is concluded from the results of this study that the workload can be reduced by controlling conditions of a manual materials handling task.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2002년도 추계학술발표대회 논문집
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• pp.241-244
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• 2002

Recently, the size of glass panel is increased to $1250 mm{\times}1100 mm{\times}0.7 mm$, whose mass is 2.65 kg, which requires much stiffer robot structure. In addition to the high stiffness, the robot hands and wrists for glass panel handling should have miller surface finishing of its outer surface to prevent particles and dusts from adhering on the surface. The maximum height of the robot structure should not be larger than 1500 mm because other automated guided vehicles (AGV) and transfer equipments have been designed within this size limit. The difference of maximum deflections of the four ends of the hands before and after loading the glass panel should be less than 2.0 mm. In this work, the robot hands and wrists for handling large glass panel displays were designed based on the axiomatic design using the finite element method along with optimization routine.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1715-1718
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• 2005

During demonstrations of a process conditioning spent nuclear fuels, it may be necessary to transport and handle Spent fuel road cuts from Post Irradiation Examination facility to Slitting device in The hot cell. It may be not easy to transport spent fuel rod cuts because rod cuts are high radioactive materials. For this purpose, we have developed a capsule for transporting and handling high radioactive materials. We have analyzed conditions of a hot cell and requirements of the device, designed and manufactured The prototype of the device, and done some performance tests. From the tests, it has been shown that transportation and handling without scattering nuclear material was smooth but the weight of capsule was heavy. These result will be reflected to a design of the improved transportation and handling device which will be used during demonstrations.

• 한국컴퓨터정보학회논문지
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• 제19권3호
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• pp.155-161
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• 2014

본 연구의 목적은 보병용 휴대 배낭 설계를 위하여 인체공학적인 물자취급 중량을 검토하여 휴대 및 이동성능에 기초한 한계하중을 분석하는데있다. 제품설계시 인체공학적 설계가이드라인과 운용현황을 조사분석하여 효율적인 운용성능을 위한 기초자료로 제공하고자 한다. 본 연구에서는 인력물자취급시 역사적 관점에서 생리학적 연구방법, 생체역학적 연구방법, 인체심리학적 연구방법들을 검토하여 보병용 휴대배낭의 휴대성 및 이동성을 분석하였다. 휴대성과 이동성 간의 관계를 분석한 결과, 단거리의 짧은 기동거리에서는 생체역학적 기준치를, 1-2시간의 중간인 이동에서는 인체심리학적 기준치를, 4시간 혹은 그 이상의 장거리에서는 생리학적 기준치를 적용하여 각각의 가이드라인들을 상호 절충하는 것이 필요한 것으로 판단된다. 본 연구에서는 보병의 물자취급시 4가지 연구방법을 제안하였다. 이러한 기존의 설계 가이드라인을 분석한 결과, 병사의 인체사이즈 측면에서는 5%tile의 경우 -091kg으로 여유중량이 부족하지만, 95%tile에서는 34.17kg까지 여유중량이 발생하는 것으로 판단된다. 이러한 연구결과는 물자취급시 편하고, 효율적인 운용성능을 창출하기 위해서 휴대중량과 이동거리에 따라 여유중량을 관리해야 할 것으로 판단된다.

• 대한인간공학회지
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• 제26권2호
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• pp.35-44
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• 2007

Work-related musculoskeletal disorders (WMSDs) are a major problem in industries in which manual materials handling is performed by workers. To prevent these WMSDs, it is necessary to understand the muscular strength capability and use this knowledge to design job and selection and assignment of workers. Even though two-hands lifting activity of manual materials handling tasks are prevalent at the industrial site, many manual materials handling tasks which require the worker to perform one-hand lifting are also very common at the industrial site and forestry and farming. However, a few researches have been done for one-hand lifting activity of manual materials handling tasks. The objective of this study is to compare one-hand and two-hands lifting strength in terms of static and dynamic strength of the lifting activity for the ranging from the height of knuckle to elbow. It is shown in this study that the isometric lifting strength of one-hand is ranging from 54.7 to 63.3% of the one of two-hands. However, it is found that there is no significant difference between a person's isometric lifting strength for left-hand and right-hand. It is also shown that there is no significant difference between the peak force under the dynamic sub-maximal loading with one-hand and two-hands lifting activity. Similar results were obtained for the peak acceleration and peak velocity under the dynamic sub-maximal loading with one-hand and two-hands lifting activity. Isometric lifting strength at the height of knuckle was ranging from 2 to 3 times of the dynamic peak force during sub-maximal lifting. It is concluded that the dynamic peak forces under the sub-maximal loading are not highly correlated with the isometric lifting strength in similar postures.