This paper describes experiments on a low-pressure pneumatic actuator and load. An impulse test is described, in which the transient behaviour of a loaded actuator, operating in a particularly simple mode, was observed. The results are used to explain the nature of the expansion and compression processes in the actuator and to aid understanding of the effects of piston leakage and friction. Numerical values are obtained for the poly tropic gas constant and for the friction and piston leakage coefficients. The conclusions are shown to be relevant to an actuator operating in more complex modes and as a component of a pneumatic servomechanism.
Get full access to this article
View all access options for this article.
References
1.
CutlandM J. ‘Response of a pneumatic servomechanism’, MSc(Fng) Thesis, 1967, Univ of London.
2.
BurrowsC RWebbC R. ‘Further study of a low-pressure on off pneumatic servomechanism’, Proc I Mech E1969 1970, Vol 184, Pt 1, pp 849–858.
3.
BownsD EBallardR L. ‘Digital computation for the analysis of pneumatic actuator systems’, Proc I Mech E1972, Vol 186, pp 881–889.
4.
ChittyA.‘Low Pressure Pneumatic Servomechanisms’, 1973, Univ of London PhD thesis.
5.
ShearerJ L. ‘Continuous Control of motion with Compressed Air’, ScD thesis, MIT1954.
6.
ChelomeyV N. ‘A study of pneumatic and hydraulic servomechanisms’, Avtomaticheskoye Upravleniye i Vychislitel'naya Tekhnika, Moscow1958, pp. 166–181. Translation by Foreign Technology Division, Air Force Systems Command, WP.AFB Ohio 1961 (FTD-TT-61–107/1 and 2).
7.
VaughanD R. ‘Hot gas actuators; some limits on the response speed’, J bas Engng, Trans Am Soc Mech Engrs1965, 87(Series D), 113.
8.
BrannR P. ‘Linear analysis of a pneumatic differential actuator with position feedback for prosthetic control’, Control, Aug and Sept 1966.
9.
BottingL REynonG TFosterK.‘The response of a high-pressure pneumatic servomechanism to step and sinewave inputs’, Proc I Mech E1969–1970Vol 184 (Pt 1), No 54.
10.
AndersenB W. ‘The Analysis and Design of Pneumatic Systems’, Wiley1967.
11.
HirtreiterA B. ‘Air springs’, Machine Design, 1 April, 1965, p 104.
12.
RogersG F CMayhewY R. ‘Eng Thermodynamics, Work and Heat Transfer’, Longmans, 1967, p 355.
13.
ParnabyJ.‘Instability due to static and Coulomb friction in autonomous control systems’. 2nd Fl Power Symp, Jan 1971.
14.
RashidA H. ‘To investigate the friction characteristics and the wear of seals in pneumatic cylinders’, Middlesex Poly, Hendon Coll, Dept of Mech Fng, BSc project rep 1972.
