Disturbance compensation techniques for controlling pneumatic actuator systems

In this paper, three disturbance compensation algorithms are experimentally evaluated considering the control problem of a rodless pneumatic cylinder. Despite its highly nonlinear dynamics, the pneumatic cylinder is modeled as a linear system including an unknown lumped disturbance. Three disturbance estimation algorithms are then employed to compensate for this lumped disturbance: the traditional linear disturbance observer (TDOB), the integral sliding-mode disturbance observer (I-SDOB) and the IMP-based SDOB (IMP-SDOB). Experimental results are presented to compare these three algorithms in terms of positioning accuracy.