Mathematical Problems in Engineering
Volume 2011 (2011), Article ID 472903, 16 pages
Research Article

Nonlinear Mathematical Modeling in Pneumatic Servo Position Applications

1Robotics Laboratory, Technology Department, UNIJUÍ—Regional University of Northwestern Rio Grande do Sul State, P.O. Box 121, Avenue Rudi Franke 540, 98280-000 Panambi, RS, Brazil
2Centro de Matemática, Computação e Cognição, UFABC, Rua Catequese 242, 3o andar, Jardim 09090-400 Santo André, SP, Brazil

Received 6 July 2010; Revised 14 March 2011; Accepted 22 March 2011

Academic Editor: Marcelo Messias

Copyright © 2011 Antonio Carlos Valdiero et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


This paper addresses a new methodology for servo pneumatic actuators mathematical modeling and selection from the dynamic behavior study in engineering applications. The pneumatic actuator is very common in industrial application because it has the following advantages: its maintenance is easy and simple, with relatively low cost, self-cooling properties, good power density (power/dimension rate), fast acting with high accelerations, and installation flexibility. The proposed fifth-order nonlinear mathematical model represents the main characteristics of this nonlinear dynamic system, as servo valve dead zone, air flow-pressure relationship through valve orifice, air compressibility, and friction effects between contact surfaces in actuator seals. Simulation results show the dynamic performance for different pneumatic cylinders in order to see which features contribute to a better behavior of the system. The knowledge of this behavior allows an appropriate choice of pneumatic actuator, mainly contributing to the success of their precise control in several applications.