• Title, Summary, Keyword: Pneumatic System

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Optimization of Design Parameters of a Pneumatic System (공압시스템의 설계 파라미터 최적화)

  • Um T.J.
    • 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.

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Intelligent control of pneumatic actuator using MPWM (MPWM을 이용한 공압 실린더의 지능제어)

  • 송인성;표성만;안경관;양순용;이병룡
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.530-535
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    • 2002
  • Pneumatic control system has been applied to build many industrial automation systems. But most of them are sequence control type because of their low costs, safety, reliability, etc. Pneumatic servo system is rarely applied to real industrial fields because accurate position control is very difficult due to its nonlinearity and compressibility of air. In pneumatic servo control system, a pneumatic servo valve can be applied, But it is very expensive and has no advantage of low cost compared with a common pneumatic system. 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 through experiments nth various loads.

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A Study on the Design of Pneumatic/Hydrauric Brake System for Automatic Guideway Transit (경량전철시스템의 공유압제동장치 설계에 관한 연구)

  • Lee, Woo-Dong
    • Proceedings of the KIEE Conference
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    • pp.344-346
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    • 2002
  • The pneumatic/nydraulic brake system is recently apply to the AGT system such merit as installation is convenient and brake force is strong or than pneumatic brake system. The pneumatic/ hydraulic brake system consist of brake operating unit, electronic control unit, air compressor and pneumatic/hydraulic tranducer. The components of it are controlled and designed to perform the function of brake system. Therefore, This paper design and the pnuematic/hydraulic brake system and propose the derection of development for AGT system.

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Experimental Study on Cushioning Characteristics of Pneumatic Cylinder with Meter-In/Meter-Out Control

  • Kim, Dong-Soo;Lee, Sang-Chun
    • International Journal of Precision Engineering and Manufacturing
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    • v.3 no.1
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    • pp.57-65
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    • 2002
  • Pneumatic cylinder is widely used fur mechanical handling systems. Often, the impact occurs at the both ends points of pneumatic cylinder and generates the destructive shock with in the structural operating members of the machine or equipment. To reduce the damage of system, therefore, shock absorbing devices are required. Cushioning of pneumatic cylinders at one or both ends of piston stroke is used to reduce the shock and vibration. The cylinder body have to withstand under conditions of high velocity and load. In this research pneumatic cushioning cylinder moving tests have been conducted for different load mass and supply pressure. The velocity of pneumatic cylinder actuation system which is set vertically with multiple orifice cushion sleeve is controled with the meter-in/out control system. This study examines the dynamic characteristics of pneumatic cylinder which are used as cushion devices. It turns out that the cushion pressure is mainly a function of the external load rather than the supply pressure. The cushion region characteristics was also revealed in the meter-in control system.

Displacement Control of Pneumatic Actuator Equipped with PLC and Proximity Sensors (PLC와 근접센서를 이용한 공압 실린더의 변위제어)

  • Kim, Gun-Hoi;So, Jung-Duck
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.17 no.2
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    • pp.90-96
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    • 2008
  • A pneumatic system was proposed to evaluate displacement accuracy of the pneumatic actuator without external load and to analyze capability of integration of the proposed valve system. The proposed pneumatic system consisted of a combination of pneumatic valves, two proximity sensors, and a programmable logic controller(PLC). The position controller is based on the PLC controller connected with the proximity sensors. Displacement accuracy of the pneumatic cylinder stroke was tested by varying air pressures of the supply and discharge-side and strokes of the pneumatic cylinder. The displacement accuracy of the pneumatic cylinder stroke increased as the supply and discharge side of air pressure increased at the stroke length of 133mm. Also the displacement accuracy increased as the stroke length increased with a fixed supply and discharge side of air pressure of the pneumatic cylinder as 3.5 and $4.5kg/cm^2$, respectively. The most accurate displacement of the pneumatic cylinder(i.e., standard deviation of 0.01 mm) was obtained at the supply and discharge side of air pressure of 4.0 and $5.0kg/cm^2$, respectively, and strokes of 170 and 190 mm among arbitrarily selected supply and discharge side air pressures and strokes.

Dynamic Characteristics of an Antagonistic Actuation with Pneumatic Artificial Muscles (공압형 인공근육을 이용한 상극구동의 동적 특성)

  • Kang, Bong-Soo;Song, Seung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.33 no.10
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    • pp.1081-1086
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    • 2009
  • This paper presents dynamic characteristics of pneumatic artificial muscles. Since the actuating performance of a pneumatic muscle is closely related to the input pressure of a pneumatic muscle, the air flow model on a valve orifice and an elastic bladder of the muscle is formulated to estimate precisely the pressure variance of pneumatic muscles during deflating and inflating process. Frequency response experiments are performed with an antagonistic system consisting of two pneumatic muscles and fast pneumatic control valves. Comparing with experimental results, the proposed model yielded good performance in estimating dynamic motions of the antagonistic system as well as the pressure variance of the pneumatic artificial muscles

Position and Force Simultaneous Trajectory Tracking Control with a Pneumatic Cylinder Driving System (공기압 실린더를 이용한 힘과 위치 동시 궤적 추적 제어)

  • Cho, M.S.;Jang, J.S.
    • Journal of Power System Engineering
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    • v.7 no.3
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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.

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Anti-lock Braking System for Commercial Vehicles with Pneumatic Brake System by Using Slip Ratio (슬립률을 이용한 상용차용 공압식 브레이크 기반 ABS 알고리즘 개발)

  • Kim, Jayu;Kwon, Baeksoon;Yi, Kyongsu
    • Journal of Auto-vehicle Safety Association
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    • v.12 no.2
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    • pp.21-26
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    • 2020
  • This paper presents an anti-lock braking system for commercial vehicles with pneumatic brake system by using slip ratio. By virtue of system reliability, most commercial vehicles adopt pneumatic brake system. However, pneumatic brake systems control is more difficult than hydraulic systems due to a longer time delay and the system nonlinearity. One of the major factors in generating braking forces is the wheel slip ratio. Accordingly, the proposed ABS strategy employs the slip ratio threshold-based valve on/off control. This threshold-based algorithm is simple but effective to control the pneumatic brake systems. The control performance of the proposed algorithm has been validated via simulation studies using MATLAB/Simulink and Trucksim. The results show ABS by using slip ratio reduces the braking distance and improves vehicle control.

High Performance Position Control of a Pneumatic System (공기압 위치 제어 시스템의 성능 향상에 관한 연구)

  • Jang, J.S.
    • Journal of Power System Engineering
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    • v.2 no.2
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    • pp.60-66
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    • 1998
  • Positioning performance with a normal pneumatic positioning system, is mainly affected by friction force on the actuator and nonlinear characteristics of the control valve. We proposed a positioning system which is composed of a pneumatic actuator and high speed control valve. for accurate and speedy positioning. Driving piston on the actuator is mounted with externally pressurized air bearings to clear the friction force. This paper studies a method in order that improves positioning ability of the pneumatic positioning system considering the nonlinear characteristics of the control valve and the actuator.

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Experimental Study of Cushioning Pneumatic Cylinder with Meter In/Meter Out Control System (메타인 및 메타아웃 제어에 의한 공기압 실린더의 쿠션특성에 관한 실험적 연구)

  • 김동수;이상천
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.2
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    • pp.97-104
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    • 2000
  • Pneumatic cylinder is widely used for mechanical handling systems. Often, the impact occurs at the both ends points of pneumatic cylinder and generates destructive shock with in the structural operating members of the machine or equipment. To reduce the damage of system, therefore, shock absorbing devices are required. Cushioning of pneumatic cylinders at one or both ends of piston stroke is used to reduce the shock and vibration. The cylinder body have to withstand under high velocity and load. In this research, the pneumatic cushioning cylinder moving tests have been conducted for different load mass and supply pressure. The velocity of pneumatic cylinder actuation system with multiple orifice cushion sleeve which is set vertically controled with meter-in/out system. This study examines the dynamic characteristics of pneumatic cylinder with cushion devices. It turns out that the cushion pressure is mainly a function of the external load rather than the supply pressure. The cushion region characteristics was also revealed in the meter-in system.

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