Research Papers

A Novel in Field Method for Determining the Flow Rate Characteristics of Pneumatic Servo Axes

[+] Author and Article Information
Paolo Righettini

Department of Engineering,
University of Bergamo,
Dalmine 24044, Italy
e-mail: paolo.righettini@unibg.it

Hermes Giberti

Mechanical Department,
Politecnico di Milano,
Milano 20156, Italy
e-mail: hermes.giberti@polimi.it

Roberto Strada

Department of Engineering,
University of Bergamo,
Dalmine 24044, Italy
e-mail: roberto.strada@unibg.it

Contributed by the Dynamic Systems Division of ASME for publication in the Journal of Dynamic Systems, Measurement, and Control. Manuscript received May 25, 2012; final manuscript received March 6, 2013; published online May 21, 2013. Assoc. Editor: Evangelos Papadopoulos.

J. Dyn. Sys., Meas., Control 135(4), 041013 (May 21, 2013) (8 pages) Paper No: DS-12-1182; doi: 10.1115/1.4024010 History: Received May 25, 2012; Revised March 06, 2013

Several strategies, in order to improve an actuator's control and to increase the bandwidth, consider the relationship between the valve's driving signal and the air flow rate. Such an approach to the control strategy takes advantage of the evaluation of the valve's characteristic parameter, known as sonic conductance. The sonic conductance can be measured following the procedure stated by the standard ISO 6358. Nevertheless, the measurement carried out according to this standard is very expensive in terms of time and air consumption. In this paper, an alternative method to evaluate the sonic conductance is presented. The method is based on a new practical approach: the sonic conductance is evaluated leaving the valve mounted on the actuator and using only the piston's position transducer. The steady state piston's motion allows us to determine the sonic conductance. The new approach allows us to get the conductance in a very short time, without the need to use a proper test bench and pressure transducers. Moreover, performing the measurements directly on the pneumatic axis allows us to characterize not only the valve but the duct connecting the valve to the actuator's chamber too.

Copyright © 2013 by ASME
Your Session has timed out. Please sign back in to continue.



Grahic Jump Location
Fig. 1

ISO 6358 test rig scheme

Grahic Jump Location
Fig. 2

5/3 proportional directional flow control valve

Grahic Jump Location
Fig. 3

Operational scheme of a pneumatic axis

Grahic Jump Location
Fig. 4

Test rig according to ISO 6358

Grahic Jump Location
Fig. 5

2–3 duct's conductance versus command signal, according to ISO 6358 method

Grahic Jump Location
Fig. 6

Temperature behavior during a set of tests

Grahic Jump Location
Fig. 8

Position versus time (dark lines) and slopes at the stroke's end (light lines)

Grahic Jump Location
Fig. 9

Piston's velocity versus position (black lines) and slopes at the stroke's end (gray lines)

Grahic Jump Location
Fig. 10

Downstream/upstream pressure ratio versus position

Grahic Jump Location
Fig. 11

ΔP versus piston's position

Grahic Jump Location
Fig. 12

Pressure versus piston's position

Grahic Jump Location
Fig. 13

Comparison between the terms of inequality in Eq. (19); P·/P (black lines), (Ax·)/(Ax + V*) (gray lines)

Grahic Jump Location
Fig. 14

Steady state velocity method versus ISO method

Grahic Jump Location
Fig. 15

Percentage variation with respect to ISO method




Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In