Improving dynamic performances of PWM-driven servo-pneumatic systems via a novel pneumatic circuit.
In this paper, the effect of pneumatic circuit design on the input-output behavior of PWM-driven servo-pneumatic systems is investigated and their control performances are improved using linear controllers instead of complex and costly nonlinear ones. Generally, servo-pneumatic systems are well known for their nonlinear behavior. However, PWM-driven servo-pneumatic systems have the advantage of flexibility in the design of pneumatic circuits which affects the input-output linearity of the whole system. A simple pneumatic circuit with only one fast switching valve is designed which leads to a quasi-linear input-output relation. The quasi-linear behavior of the proposed circuit is verified both experimentally and by simulations. Closed loop position control experiments are then carried out using linear P- and PD-controllers. Since the output position is noisy and cannot be directly differentiated, a Kalman filter is designed to estimate the velocity of the cylinder. Highly improved tracking performances are obtained using these linear controllers, compared to previous works with nonlinear controllers.
Taghizadeh
Mostafa
M
Mechanical Eng. Department, KNToosi University of Technology, Tehran, Iran. taghizadeh@pwut.ac.ir
Ghaffari
Ali
A
Najafi
Farid
F
D000465:Algorithms; D003198:Computer Simulation; D004867:Equipment Design; D005246:Feedback; D007221:Industry / Q000295:instrumentation*; D007700:Kinetics; D016014:Linear Models; D017711:Nonlinear Dynamics; D011312:Pressure