Precise Position Control of Pneumatic Servo System Considered Dynamic Characteristics of Servo Valve

A simulation model of a rotary pneumatic servo system has been developed and verified against an experimental system. The double-acting rotary actuator is a novel device utilizing flexible inflatable bladders. The device differs from conventional pneumatic cylinders in that it exhibits low levels of friction, as it has no sliding seals, but it does suffer from hysteresis caused by bladder distortion. The objective of this study was to develop a tool with which to investigate the effect of various forms of hysteresis and other parameters on system performance. The dynamic model utilizes a linearized analysis of pneumatic components based on earlier studies. The principal advance described in this paper relates to the inclusion of non-linear elements. These are hysteresis caused by friction or the distortion of flexible components, and a digital controller implementation. The simulation successfully predicted all major modes of behaviour. Simplified models of rubber and coulomb friction-induced hysteresis modified simulation performance in line with experimental results. An investigation in simulation showed that coulomb friction-induced hysteresis had a greater damping effect than that caused by distorting the bladders. This result applies only to position control, as hysteresis has been shown not to provide damping in trajectory control applications.

Download Full-text

CONTROL SYSTEM DESIGN OF A PNEUMATIC SERVO SYSTEM CONSIDERING THE DYNAMIC CHARACTERISTICS OF THE SERVO VALUE

Proceedings of the JFPS International Symposium on Fluid Power ◽

10.5739/isfp.2008.457 ◽

2008 ◽

Vol 2008 (7-2) ◽

pp. 457-460 ◽

Cited By ~ 3

Author(s):

Masahiro HIRANO ◽

Kazutoshi SAKAKI ◽

Toshinori FUJITA ◽

Kenji KAWASHIMA ◽

Toshiharu KAGAWA

Keyword(s):

Control System ◽

System Design ◽

Dynamic Characteristics ◽

Servo System ◽

Control System Design ◽

Pneumatic Servo System

Download Full-text

An analog feedback with iterative procedure for improving closed loop performances in position control of pneumatic servo system

1997 European Control Conference (ECC) ◽

10.23919/ecc.1997.7082470 ◽

1997 ◽

Author(s):

K. Hamiti ◽

A. Voda-Besancon ◽

H. Roux-Buisson

Keyword(s):

Iterative Procedure ◽

Closed Loop ◽

Position Control ◽

Servo System ◽

Pneumatic Servo System

Download Full-text

O-typed position control on pneumatic servo system

The Proceedings of JSME annual Conference on Robotics and Mechatronics (Robomec) ◽

10.1299/jsmermd.2021.2p1-h09 ◽

2021 ◽

Vol 2021 (0) ◽

pp. 2P1-H09

Author(s):

Masahiro TAKAIWA ◽

Masayuki MIBA

Keyword(s):

Position Control ◽

Servo System ◽

Pneumatic Servo System

Download Full-text

Effect of Servo Valve Dynamic on Precise Position Control of a Pneumatic Servo Table

International Journal of Automation Technology ◽

10.20965/ijat.2008.p0043 ◽

2008 ◽

Vol 2 (1) ◽

pp. 43-48 ◽

Cited By ~ 5

Author(s):

Toshinori Fujita ◽

◽

Kenji Kawashima ◽

Takashi Miyajima ◽

Taro Ogiso ◽

...

Keyword(s):

Natural Frequency ◽

Trajectory Tracking ◽

Position Control ◽

Tracking Error ◽

Air Bearing ◽

Precise Position ◽

Servo Valve ◽

Valve Dynamics ◽

Feedforward Controller ◽

Tracking Response

In experimentally investigating the effect of servo valve dynamics on control of a pneumatic servo table with an air bearing, we propose control using a PDD2 and a feedforward controller, then test step and trajectory tracking response with natural servo valve frequencies. We confirmed that pneumatic servo performance is affected by servo valve dynamics. We found that tracking error fell below +- 0.5 mm when the servo valve has a natural frequency of 300 Hz.

Download Full-text