• 동력기계공학회지
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• 제4권2호
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• pp.58-64
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• 2000

A method for the position control of a pneumatic cylinder using a linearized controller is proposed. Pneumatic cylinder has highly nonlinear characteristics and modelling of the system has been difficult. Compliance of the pneumatic cylinder is materially changed according to the operating position. So, in the case that fixed gain controller obtained by a linearized model at a specified position is used, response of the cylinder should be changed according to the operating position. In order to get a designed results regardless of operating positions, a controller for compensation of the nonlinear characteristic with a linearlization compensator is designed and simulation results show that this method is appropriate for the control object.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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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.

• 로봇학회논문지
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• 제6권1호
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• pp.34-41
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• 2011

This paper presents a frequency-response test performed on an antagonistic actuation system consisting of two Mckibben pneumatic artificial muscles and a pneumatic circuit. A linear model, capable of estimating the dynamic characteristics of the antagonistic system in the operating range of pneumatic artificial muscles, was optimally calculated based on frequency-response results and applied to a multiple simultaneous specification control scheme. Trajectory tracking results showed that the presented multiple simultaneous specification controller, built experimentally by three PD typed sample controllers, satisfied successfully all required control specifications; rising time, maximum overshoot, steady-state error.

• 대한기계학회논문집A
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• 제30권6호
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• pp.662-669
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• 2006

The pneumatic muscle actuator consists of an air bellows tube with two end-flanges. The air bellows tube is made from rubber layers and flexible sheathing formed from nylon 6 fibers. This structure can be stretched or compressed to convert the radial expansive forces into contractile forces. We performed the finite element analysis and the performance test of pneumatic muscle actuator. Also, the pneumatic muscle actuator was manufactured and tested by home-made tester. The results of FEA was similar with performance test below the maximum error of 42 %.

• 유공압시스템학회논문집
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• 제8권3호
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• pp.21-26
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• 2011

Nonlinear seal friction in pneumatic cylinders can impede the performance of pneumatic systems designed for high precision positioning with favorable high speed actuation. The behaviour of an elastomeric piston seals in high speed pneumatic cylinders is analyzed by nonlinear finite element analysis using ABAQUS. The contact pressures, stress and strain distributions and frictional forces of the squeeze type piston seal are simulated with variation of the seal radial installed interference, the operating pressures, friction coefficients and piston rod velocities. The nonlinear finite element model of the squeeze type piston seal is used to predict deformation of a seal, friction force and contact pressure distributions.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.267-271
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• 1997

In this study, swing phase dynamic simulation of above-knee prosthesis is performed. The prosthesis consists of a single axis knee mechanism and pneumatic cylinder. The numerical modelling of the prosthesis is analyzed in two dimensions. The governing equation of thermodynamical pneumatic cylinder model is applied to construct the control of lower limb during swing phase. Knee flexion angle with respect to the orifice diameter of the pneumatic cylinder is produced. This analysis will be very useful to the design of pneumatic cylinder in prosthesis.

• 유공압시스템학회:학술대회논문집
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• 유공압시스템학회 2010년도 춘계학술대회
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• pp.99-104
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• 2010

Nonlinear seal friction in pneumatic cylinders can impede the performance of pneumatic systems designed for high precision positioning with favorable high speed actuation. The behaviour of an elastomeric piston seal in high speed pneumatic cylinders is analysed by nonlinear finite element analysis using ABAQUS. The contact pressures, stress and strain distributions and frictional forces of the piston seal are simulated with variation of interference fits, supply pressures, friction coefficients and piston rod velocities. The nonlinear finite element model of the piston seal is used to predict deformation of a seal, friction force and contact pressure distributions.

• 한국자동차공학회논문집
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• 제24권3호
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• pp.310-318
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• 2016

The demands for vehicle safety systems such as ABS and ESC have been increased. Accurate vehicle state estimation is required to realized the abovementioned systems and tire-friction coefficient is crucial information. Estimation of lateral tire-road friction coefficient using pneumatic trail information is mainly dealt in this paper. Pneumatic trail shows unique characteristics according to the wheel side slip angle and these property is highly sensitive to vehicle lateral motion. The proposed algorithm minimizes the use of conventional tire models such as magic formula, brushed tire model and Dugoff tire model. The pure side slip maneuver, which means no longitudinal dynamics, is assumed to achieve the ultimate goal of this paper. A simulation verification using Carsim and Simulink is performed and the results show the feasibility of the proposed algorithms.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.1104-1109
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• 1991

Recently, Pneumatic Actuation System (PAS) has been used increasingly as a high performance fin-control servo actuation systems because of the special advantages of pneumatic units: primarily their low cost, small size, light weight, and tolerance to broad temperature extremes. In this study, a nonlinear model of PAS is derived through the detailed analysis of the major components in the typical system. The model includes nonlinear flow-pressure relationships of the flow through the solenoid valve openings and orifices, PWM algorithm for driving two solenoid valves as a closed-center 3-way valve for minimum gas consumption, solenoid valve dynamics, saturation, and friction. Simulation results are compared with the experimental ones for square and sinusoidal inputs to see the validity of the model. Independent of the shape and magnitude of the input signals, both results are in good agreements with minor difference.

• 유공압시스템학회:학술대회논문집
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• 유공압시스템학회 2010년도 춘계학술대회
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• pp.93-97
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• 2010

Wheel skids may occur during train operations due to low adhesion at the wheel-rail contact point abnormally, and the skids, in turn, result in flats appearing on the wheels, which affect safety and ride comfort significantly. Thus, anti-skid control has a crucial role for safe braking and prevention from flats that could cause a disastrous train accident. This paper presents simulation studies on an anti-skid control unit (ASCU) with a brake system of a rolling stock including a pneumatic model for brake power supply and dump valve operation.