Abstract
Pneumatic actuators are widely used as low cost actuators, but there is difficulty in controlling the precise position with the pneumatic actuator. The main reasons for this are the high compressibility of air in the cylinder and nonlinear friction of the piston rods. We made use of a dither so as to decrease the nonlinear characteristics of friction and disturbance observer to give more robustness to the change in loads to the position control of the actuators. We realized the precise position control of the pneumatic lifters which consisted of a load table and four pneumatic actuators.
