Nonlinear position control of pneumatically driven stage considering friction characteristics of pneumatic cylinder

This paper deals with modeling of pneumatic stage considering friction characteristics and designing controller system based on operator theory. The use of stages with pneumatic actuators in industry requires precise position control. Pneumatic stage has nonlinear characteristics, one of the causes of which is friction in the pneumatic cylinder. There is friction between the pneumatic cylinder and the cross-section of the piston, but few studies about pneumatic stage has considered friction. Therefore, we propose the model of pneumatic stage which takes friction characteristics into account and a controller that simultaneously performs reference value tracking by using operator-based right coprime factorization. Moreover, the whole control system is validated by comparing the model considering friction and operator-based theory with the one that previous study by Simulation and experimental run.