Pneumatic motion control using magnetorheological technology

A new concept for pneumatic motion control is discussed that is enabled by magnetorheological (MR) technology. This concept involves placing MR braking devices functionally in parallel with pneumatic actuators. Through closed-loop feedback of a position sensor, accurate and robust motion control is achieved. Furthermore, these systems address many of the problematic issues associated with other pneumatic motion control systems such as: complexity, compliance and sensitivity to air quality. The basic system structure is presented as well as several concepts for MR-pneumatic actuators. A general control structure is proposed that can implicitly accommodate the inherent tradeoff between speed and accuracy in motion control systems. Some laboratory data is presented that explores the behavior of these systems and the nature of this tradeoff. Ideally, this technology will fill a niche between unsophisticated directional control and complex servo control systems.