• 동력기계공학회지
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• 제7권3호
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• pp.40-47
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• 2003

In this study, position and force simultaneous trajectory tracking control apparatus with pneumatic cylinder driving system is proposed. The pneumatic cylinder driving system that consists of two pneumatic cylinders constrained in series and two proportional flow control valves offers a considerable advantage as to non-interaction of the actuators because of the low stiffness of the pneumatic actuators. The controller applied to the driving system is composed of a non-interaction controller to compensate for interaction of two cylinders and a disturbance observer to reduce the effect of model discrepancy of the driving system in the low frequency range that cannot be suppressed by the non-interaction controller. The experimental results with the proposed control apparatus show that the interacting effects of two cylinders are eliminated remarkably and the proposed control apparatus tracks the given position and force trajectory accurately.

• 유공압시스템학회논문집
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• 제5권1호
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• pp.1-5
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• 2008

Pneumatic driving systems have hard non-linear characteristic and large friction force compared with driving power. Hence, it cannot be robust against parameter uncertainties, modelling error, disturbance and noise. In this study, we apply a mixed $H_2/H_{\infty}$ control to the generalized plant for a pneumatic driving apparatus system including parameter uncertainty and disturbance. In order to design the $H_2/H_{\infty}$ controller, we use the LMI technique. To evaluate control performance and robust stability of the designed controller, we compare it with a conventional controller such as PVA(Position-Velocity-Acceleration state controller) using the simulation results. As a result, it can be known that designed controller shows better robust stability than the conventional controller.

• 유공압시스템학회논문집
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• 제3권1호
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• pp.15-19
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• 2006

In this study, a measurement method of leakage flow-rate for pneumatic driving apparatus is proposed. The existing measurement methods of leakage flow-rate of air need disassemble the test component. Therefore, there is no effective method to measure the leakage flow-rate while operating pneumatic driving apparatus. In this study, the leakage flow-rate is measure from the pressure change in an isothermal chamber that can realize isothermal conditions by stuffing steel wool into it. Therefore, wide range of flow-rate could be measured only from the pressure response and the leakage flow-rate can be measured during operating pneumatic driving apparatus. The effectiveness of the proposed method is proved by experimental results.

• 동력기계공학회지
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• 제11권4호
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• pp.98-102
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• 2007

In this study, a measurement method of leakage flow-rate for pneumatic driving apparatus is proposed. The existing measurement methods of leakage flow-rate of air need disassemble the test component. Therefore, there is no effective method to measure the leakage flow-rate while operating pneumatic driving apparatus. In this study, the leakage flow-rate is measured from the pressure change in an isothermal chamber that can realize isothermal conditions by stuffing the steel wool into it. Therefore, a wide range of flow-rate could be measured only from the pressure response and the leakage flow-rate can be measured during operating pneumatic driving apparatus. The effectiveness of the proposed method is proved by experimental results.

• 동력기계공학회지
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• 제21권6호
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• pp.101-109
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• 2017

The pneumatic driving system has advantages such as high output power per weight and low heat generation rate. However, it is difficult to control the position because of its strong non-linearity such as large friction forces compared to driving force, and heat transfer characteristics that change during operation. Therefore, in order to achieve the control objectives, a robust controller should be designed considering modeling error and model uncertainty. In this paper, a sliding mode controller is designed to improve the position control performance of pneumatic cylinder driving system. Experimental results show that the designed controller achieves the designed control objectives even if the model of the cylinder driving system, such as the initial pressure inside the cylinder and the initial position of the piston is changed.