Pneumatic servo rotary actuator with a MRF-damper

It is difficult to implement high-precision positioning servo control for the traditional pneumatic rotary actuator. We introduced the magneto-rheological fluid (MRF) technology, and the mechanical structure of a new servo-controlled damping pneumatic rotary actuator is designed. The positioning servo system of the new pneumatic rotary actuator is constructed and the mathematical model is established in this paper. The MRF damper characteristics of torque and dynamic response are investigated through experiments. The experiments show that the positioning servo system using control algorithms of braking angle compensation provides more robust against the pressure fluctuation and it can provide the precision positioning under different loads with arbitrary speed and point. The research provides theoretical and experimental basis for the MRF technology application in the pneumatic rotary positioning servo control.