• 동력기계공학회지
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• 제15권6호
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• pp.95-100
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• 2011

In this study, an evaluation equation of energy efficiency of pneumatic driving apparatus is proposed. The evaluation equation is derived from state equation and energy equation of air in a control volume, and, the equation of motion of a moving part of a pneumatic cylinder. As a result, distribution of consumption energy and energy efficiency of pneumatic driving apparatus can be analyzed quantitatively. The effectiveness of the proposed method is proved by a pneumatic cylinder driving apparatus using a meter-out driving method.

• 제어로봇시스템학회논문지
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• 제11권2호
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• pp.103-108
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• 2005

Loading/Unloading task in the real industry is performed by crane, but most of the loading/unloading task with the weight of 5kg∼30kg is done by human workers and this kind of work causes industrial disaster of workers. Therefore it is necessary to develop low cost loading/unloading manipulator system to prevent this kind of industrial accidents. This paper is concerned with the design and fabrication of 2 axis pneumatic manipulators using on/off solenoid valves and accurate position control without respect to the external load and low damping in the pneumatic rotary actuator. To overcome the change of external load, switching of control parameter using LVQNN (Learning Vector Quantization Neural Network) is newly applied, which estimates the external loads in the pneumatic cylinder. As an underlying controller, a state feedback controller using position, velocity and acceleration is applied to the switching control system. The effectiveness of the proposed control algorithms are demonstrated through experiments of pneumatic cylinder with various loads.

• 유공압시스템학회논문집
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• 제5권1호
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• pp.6-12
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• 2008

ISO pneumatic cylinder reliability test requires air leakage measurement. Air cylinder has many parts and the leakage shall be measured before, during and after endurance test, and, the leakage should smaller than the specified value. The existing measurement method needs complex operation and the calibration of leak detector, and, has to separate the testing cylinder from endurance test device, which causes the change of contact condition of seal in the cylinder. Therefore, it is hard to evaluate the air leakage during endurance test, and guarantee the reliability of the conventional measurement method. In this paper, a new method for air leakage measurement using isothermal chamber, which does not requires calibration or temperature compensation, and, can measure air leakage accurately with quite simple operations, is proposed. As a result, reliability of air leakage measurement can be improved because the proposed method does not have to separate the testing cylinder from the endurance test device for air leakage measurement. The effectiveness of the proposed method is proved by error analysis of leak measurement from experimental result.

• Journal of Mechanical Science and Technology
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• 제19권5호
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• pp.1107-1115
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• 2005

In this study, a position and force simultaneous trajectory tracking control algorithm is proposed for a driving apparatus that consists of two pneumatic cylinders connected in series. The controller applied to the driving apparatus is composed of a non-interaction controller to compensate for interaction between cylinders and a disturbance observer aimed to reduce the effect of model discrepancy that cannot be compensated by the non-interaction controller. The effectiveness of the proposed control algorithm is proved by experimental results.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.1193-1194
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• 2012

• 대한기계학회:학술대회논문집
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• 대한기계학회 2005년도 창립60주년 기념 추계 학술대회
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• pp.198.1-198.1
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• 2005

• Journal of Biosystems Engineering
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• 제37권3호
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• pp.155-165
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• 2012

This study was performed to offer the data for design of the seedling bed transfer equipment to make the automation of working process in a plant factory. The seedling bed transfer equipment pushing the seedling bed with bearing wheels on the rail for interconnecting each working process by a pneumatic cylinder was made and examined. The examined transfer force to push the seedling bed with a weight of 178.9 N by the pneumatic cylinder with length of 60 cm and section area of 5 $cm^2$ was measured by experiments. The examined transfer forces was compared with theoretical ones calculated by the theoretical formula derived from dynamic system analysis according to the number of the seedling bed and pushing speed of the pneumatic cylinder head at no load. The transfer function of the equipment with the input variable as the pushing speed $V_{h0}$(m/s) and the output variable as the transfer force f(t)(N) was represented as $F(s)=(V_{h0}/k)(s+B/M)/(s(s^2+Bs/M+1/(kM))$ where M(kg), k(m/N) and B(Ns/m) are the mass of the bed, the compression coefficient of the pneumatic cylinder and the dynamic friction coefficient between the seedling bed and the rail, respectively. The examined transfer force curves and the theoretical ones were represented similar wave forms as to use the theoretical formular to design the device for the seedling bed transfer. The condition of no vibration of the transfer force curve was $kB^2>4M$. The condition of transferring the bed by the repeatable impact and vibration force according to difference of transfer distance of the pneumatic cylinder head from that of the bed was as $Ce^{-\frac{3{\pi}D}{2\omega}}<-1$, where ${\omega}=\sqrt{\frac{1}{kM}-\frac{B^2}{4M^2}}$, $C=\{\frac{\frac{B}{2M}-\frac{1}{kB}}{\omega}\}$, $D=\frac{B}{2M}$. The examined mean peak transfer force represented 4 times of the stead state transfer force. Therefore it seemed that the transfer force of the pneumatic cylinder required for design of the push device was 4Bv where v is the pushing speed.

• Fibers and Polymers
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• 제7권2호
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• pp.146-157
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• 2006

Traditional spinning systems have reached profitability limits in developed countries due to high production costs and low system productivity. Pneumatic spinning is seen as a developing system, because productivity is much higher than conventional systems. This study evaluates one of the main problems to increase productivity in pneumatic spinning, where air mass-flow is dragged by the drafting cylinders. This flow interacts with the incoming fibres deviating them from their expected path. Via laser anemometry, airflow velocity distribution around drafting cylinders has been measured and it has been found that vorticity is created at the cylinder's inlet. Extensive CFD simulation on the air flow dragged by the cylinders has given a clear insight into the vortex created, producing valuable information on how cylinder design affects the vorticity created. Several drafting cylinder designs have been tested without giving any improvement in productivity. However, the use of a drafting cylinder with holes in it produced good results to the problem of air currents, strongly reducing them and therefore allowing a sharp increase in yarn quality, as well as an increase in productivity. An extensive study on vortex kinematics has been undertaken, bringing with it a better understanding of vortex creation, development and breakdown.

• 드라이브 ㆍ 컨트롤
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• 제12권4호
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• pp.54-59
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• 2015

Due to the tendency to use high speed pneumatic cylinders to improve productivity, cushioning devices are adopted to decelerate the piston motion of pneumatic cylinders to reduce noise, vibration, and impact. This paper presents a comparison of the cushion characteristics of a high speed pneumatic cylinder with a relief valve type cushioning device. The system parameters selected are the damping coefficient, Coulomb friction, heat transfer coefficient, and cracking pressure of the relief valve in the air cushioning device. The integral of the time multiplied square error (ITSE) is used to quantitative measure the cushioning performance to assess the effect of varying these. The cushioning performance achieved good results when the ITSE is a minimum value. In a comparison of the piston displacement and velocity with the variations in system parameters, the heat transfer coefficients are not as significantly affected as the other. Also, the cracking pressure of the relief valve is mainly affected by the pressure and temperature in the cushion chamber.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1428-1432
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• 2007

The object of this paper is development of pneumatic servo actuator technique for energy saving type. In this paper, consist of pneumatic servo actuator technique is pneumatic servo valve, pneumatic motor and cylinder. This technique applied a automobile, aerospace engineering, a ship, defence industry and industrial machine because it have high response, high speed, high precision control, low friction etc., compare with previously technique. But it depend on import the whole quantity. So this study, suggest that through the development of servo actuator applicable the use of industrial field.