• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.1191-1192
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• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.424-427
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• 2002

Pneumatic control systems have the potential to provide high output power to weight and size ratios at a relatively low cost. However, they are mainly employed in open-loop control applications where positioning repeatability is not of great importance. This paper presents precision positioning control of pneumatic servo cylinder with on-off valve, Pneumatic low-friction cylinder with servo valve and DC servo motor under parameter variations. Basically positioning control uses PID controller, where needs a linearized model. A neural network is added to a PID controller to compensator nonlinearity of the system and an influence of friction force is consider as disturbance. The performances of the proposed algorithms were compared by experiments with them of PID controller. From those experiments is was shown that the proposed algorithms are more efficient about settling time, steady 7tate error and overshoot than PID control algorithm.

• Transactions of The Korea Fluid Power Systems Society
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• v.2 no.4
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• pp.1-6
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• 2005

This paper presents optimization of a pneumatic control system whose design parameters have been optimized so that the desired dynamic characteristics of cylinder position was obtained. The pneumatic system is used as transferring and stacking equipment for solid freeform fabrication system which has been widely used in design verification applications. The pneumatic system mainly consists of pneumatic control valves and cylinders. The system was modeled by using several principles for pneumatic components. The system was optimized to obtain dynamic performance with enough damping to reduce cylinder vibration. A fuzzy controller has been applied to fulfill the dynamic performance requirements of the pneumatic system. The simulation results show that the fuzzy controller is more effective than a PD controller.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1244-1249
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• 2008

This paper shows a perfonnance analysis for pneumatic servo cylinder. The pistons without seal have partly cylindrical and conical shapes. 2 dimensional Reynolds equation and FD(finite differential) numerical techniques are utilized for the perfonnance analysis. The relationship among self-centering forces and leakage flows are investigated. Also, optimal design values for a servo cylinder are presented. A prototype of servo cylinder which had rod bearing with four pockets, five pockets, and six pockets was manufactured respectively.

• Journal of Power System Engineering
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• v.16 no.2
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• pp.60-65
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• 2012

Pneumatic actuators are clean, lightweight, and can be easily serviced, whereas low energy efficiency has been considered as a critical shortcoming compared with corresponding hydraulic and electrical actuators. This study describes a new design method of pneumatic cylinder driving apparatus by lowering a supply pressure. The simulation study demonstrates that the designed system with the proposed method can operate at the smaller energy consumption state compare to the designed system with the conventional method for the specified working conditions.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.71-75
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• 1994

This paper presents a method of optimal design of an automatic transfer system which is controlled by the electro-pneumatic servo scheme. The electro-pneumatic automatic transfer system can move parts to desired points or displace defective parts. The dynamic performance of the system can be examined by observing the behavior of the output. The output of the servo control system is the motion of the cylinder, pneumatic actuator. The dynamic performance of the cylinder is governed by the parameters of the components of the entire system. The optimal design can be accomplished by selecting of the parameters such that the desired dynamic performance of the cylinder is obtained. The optimal set of parameters might be obtained through the repeated simulations. Repeated simulations, however, is not effective to determine the optimal set of parameters since the set of parameters is large. This paper presents modeling, application of an optimization method, and the numerical results. The optimization algorithm utilizes the concept of the conjugate gradient method. The results show that the suggested optimization scheme can render faster convergence of iteration compared to other method based on an algebraic optimization method and can reduce the design efforts.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.65.2-65
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• 2002

This paper is concerned with the accurate position control of a rodless pneumatic cylinder using On/Off solenoid valve. A novel Intelligent Modified Pulse Width Modulation(MPWM) is newly proposed. The control performance of this pneumatic cylinder depends on the external loads. To overcome this problem , switching of control parameter using artificial neural network is newly proposed, which estimates external loads on rodless pneumatic cylinder using this training neural network. As an underlying controller, a state feedback controller using position, velocity and acceleration is applied in the switching control the system. The effectiveness of the proposed control algorithms are demonstrated...on/off solenoid valve, load estimation, MPWM, Artificial neural network.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.12
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• pp.2926-2934
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• 2000

This study presents a direct adaptive controller which is derived by using Lyapunovs direct methods for trajectory tracking control of a pneumatic cylinder. The structure of the controller is very simple and computationally efficient because it does not use either the dynamic model or the parameter values of the pneumatic system. The bounded stability of the system is shown in the presence of the bounded unmodeled dynamics. The bounded size of tracking errors can be made arbitrarily small without giving andy influences on either input or output variables. The trajectory tracking performance and the stability of the control system is verified experimentally. The results of the experiments show that the proposed controller tracks the given trajectories, sine function and cycloidal function trajectories, more accurately than PD controller does, and it stabilizes the system and adaptive variables.

• Journal of Advanced Marine Engineering and Technology
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• v.23 no.6
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• pp.794-805
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• 1999

Pneumatic cushioning cylinders are commonly employed for vibration and shock control. A mathematical simulation model of a double acting pneumatic cushioning cylinder designed to absorb shock loads is presented which is based on the following assumptions; ideal equation of state isentropic flow through a port conservation of mass polytropic thermodynamics single degree of freedom piston dynamics and energy equivalent linear damping. These differential equation can be solved through numerical integration using the fourth order Runge-Kutta method. An experimental study was conducted to validate the results obtained by the numerical integra-tion technique. Simulated results show good agreement with experimental data. The computer simulation model presented here has been extremely useful not only in understanding the has been extremely useful not only in understanding the basic cushioning but also in evaluating different designs.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.7
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• pp.40-45
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• 2001

This paper proposes a methodology for the small-displacement-movement of a piston and develops a hybrid control algorithm for the precision position control of a pneumatic rodless cylinder. The pneumatic system uses the voltage-proportional solenoid valves to minimum valve switching since the on/off type valves are create diffculties for accurate position control and induce a lot of valve switching. For the accurate position control a methodology for the small-displacement-movement of the piston is developed and identified experimentally. The main consideration on the development of the hybrid control law is to eliminate a stick-slip phenomenon in the pneumatic control system. This paper addresses these critical issues and presents experimental results for the pneumatic control system.