Abstract
Pneumatic actuators are widely used as low cost actuators, but there is difficulty in the precise positioning of the actuators in general. The one main reason for this is that the characteristics of the actuators vary according to the positions due to the compressibility of air. Many papers on the trials to eliminate the effects of the variation of the characteristics have been published but the effective method to maintain the robustness of the position control is not found by now. We think that LTI (Linear Time Invariant) controllers are not adequate for the plants whose parameters change widely. In this report, we have adopted the scheduled controller to eliminate the effect of the variation of cylinder parameters, and designed the controller by making use of LMI (Linear Matrix Inequality). The experimental results show the effectiveness of the control systems.
