Adaptive gain control of pneumatic servo systems with disturbance observers and fuzzy logic

Pneumatic actuators can offer high performance at low cost, but often suffer various disturbances depending on their operating conditions. In this paper, the application of a robust control scheme with disturbance observers and adaptive gains to a pneumatic servo system is presented. The disturbance observers compensate for the effects of external load disturbances and parameter variations of the plant. The variable components adjusted by fuzzy inference act to reduce estimation errors of the observers. The performance and robustness of the controller are demonstrated in simulation studies of tracking problems.