• 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.

• Journal of Mechanical Science and Technology
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• 제19권2호
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• pp.529-539
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• 2005

The development of a fast, accurate, and inexpensive position-controlled pneumatic actuator that may be applied to various practical positioning applications with various external loads is described in this paper. A novel modified pulse-width modulation (MPWM) valve pulsing algorithm allows on/off solenoid valves to be used in place of costly servo valves. A comparison between the system response of the standard PWM technique and that of the modified PWM technique shows that the performance of the proposed technique was significantly increased. A state-feedback controller with position, velocity and acceleration feedback was successfully implemented as a continuous controller. A switching algorithm for control parameters using a learning vector quantization neural network (LVQNN) has newly proposed, which classifies the external load of the pneumatic actuator. The effectiveness of this proposed control algorithm with smooth switching control has been demonstrated through experiments with various external loads.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1012-1017
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• 2003

The development of a fast, accurate, and inexpensive position-controlled pneumatic actuator that may be applied to a variety of practical positioning applications with various external loads is described in this paper. A novel modified pulso width modulation (MPWM) valve pulsing algorithm allows on/off solenoid valves to be used in place of costly servo valves. A comparison between the system response of standard PWM technique and that of the novel modified PWM technique shows that the control performance is significantly increased. A state feedback controller with position, velocity and acceleration feedback is successfully implemented as the continuous controller. Switching algorithm of control parameter using learning vector quantization neural network (LVQNN) is newly proposed. which estimates the external loads of the pneumatic actuator. The effectiveness of the proposed control algorithms are demonstrated through experiments with various loads.

• 한국정밀공학회지
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• 제20권8호
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• pp.86-93
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• 2003

The development of a fast, accurate, and inexpensive position-controlled pneumatic actuator that may be applied to a variety of practical positioning applications with various external loads is described in this paper. A novel modified pulse width modulation (MPWM) valve pulsing algorithm allows on/off solenoid valves to be used in place of costly servo valves. A comparison between the system response of standard PWM technique and that of the novel modified PWM technique shows that the control performance is significantly increased. A state feedback controller with position, velocity and acceleration feedback is successfully implemented as the continuous controller. Switching algorithm of control parameter using learning vector quantization neural network (LVQNN) is newly proposed, which estimates the external loads of the pneumatic actuator. The effectiveness of the proposed control algorithms are demonstrated through experiments with various loads.

• 대한기계학회논문집A
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• 제20권10호
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• pp.3186-3198
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• 1996

When a robot is to have contact with its enviornment, such as a medi-care robot, it would be advantageous for the robot to have a high compliance. For this reason, a robot having not only a flexible link but also an actuator with compliance, is desirable. This paper is concerned with the position and vibration control of 1 degree of freedom flexible robot using a pneumatic artificial muscle actuator. The dynamics of the manipulator assumed to be and Euler-Bernoulli beam are derived on the basis of the linear mathematical modle. Although this pneumatic artifical muscle actuator has many merits for the compliance robot, it is difficult to make an effective control scheme of this system because of ths nonlinearity and uncertainty on the dynamics of the actuator. By designing a controller using .mu.-synthesis, robust performance against measurement noise, various modeling uncertainties on the dynamics of the servo valve, actuator and mainpulator, is achieved. The effectiveness of the proposed control method is illustrated through simulations and experiments.

• 한국자동차공학회논문집
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• 제14권6호
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• pp.160-170
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• 2006

If hydraulic pump controlled by mechanical type regulator has more than one control function, the construction of regulator will be very complicated and control performance falls drastically. It is difficult to have more than one control function for hydraulic pump controlled by electronic type hydraulic valve due to the inconsistency of controllers. This paper proposes a multi-function control technique which controls continuously flow, pressure and power by using EPPR(Electronic Proportional Pressure Reducing) valve in swash plate type axial piston pump. Nonlinear mathematical model is developed from the continuity equation for the pressurized control volume and the torque balance for the swash plate motion. To simplify the model we make the linear state equation by differentiating the nonlinear model. A reaction spring is installed in servo cylinder to secure the stability of the control system. We analyze the stability and disturbance by using the state variable model. Finally, we review the control performances of flow, pressure and power by tests using PID controller.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.951-955
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• 2004

Piezoelectric(PZT) actuator can substitute for solenoid which is used in fluid control field because it has faster response times and no possibility of explosion. Besides, it is available in a high temperature and it has low energy consumption. In this study, pneumatic micro valve, bimorph type PZT actuator using the softner type PZT, carbon plate as a shim and its controller circuit were suggested and investigated. Performance tests and characteristics analysis, such as displacement, force, hysteresis and frequency properties, were carried out. The displacement of the actuator measured at the end point was 63 ${\mu}m$., force of the actuator was 0.052 N and maximum operating frequency was 15Hz. Also, characteristics of the micro valve with PZT actuator were evaluated in a testing system. The results show that the suggested PZT actuator is suitable for micro valve.