Abstract To improve the measurement precision of flow rate characteristics of pneumatic components, a new measurement method is proposed, which is based on the dynamic regularity of instantaneous polytropic exponents during discharge. The dynamic regularity of polytropic exponents is obtained by the stop method, and it can be concluded as two change stages based on pressure time constant. According to piecewise polynomial fitting curves of instantaneous polytropic exponents, a new algorithm for the identification of flow rate characteristics is proposed. This method can accurately measure some components with a large sonic conductance and a small critical pressure ratio. Four pneumatic components are measured to compare the identification precision of those different methods. The results of comparison show that the new polytropic exponent method and its new algorithm have the higher precision than other alternative methods for the ISO6358 method. The identification errors of sonic conductance of the new method are less than 3%, and the identification errors of critical pressure ratio of the new algorithm are less than 15%.
[1]
Toshiharu Kagawa,et al.
Determination of flow-rate characteristics for pneumatic components using a quasi-isothermal tank with temperature compensation
,
2010
.
[2]
David R. Otis.
Thermal Damping in Gas-Filled Composite Materials During Impact Loading
,
1970
.
[3]
B. Andersen,et al.
The Analysis and Design of Pneumatic Systems
,
1976
.
[4]
Kenji Kawashima,et al.
Instantaneous Flow Rate Measurement of Ideal Gases
,
2000
.
[5]
Kenji Kawashima,et al.
Determination of Flow Rate Characteristics of Pneumatic Solenoid Valves Using an Isothermal Chamber
,
2004
.
[6]
Salvador de las Heras.
A New Experimental Algorithm for the Evaluation of the True Sonic Conductance of Pneumatic Components using the Characteristic Unloading Time
,
2001
.