Project - Design and Control Methods for High-Accuracy Variable Reluctance Actuators

Design and Control Methods for High-Accuracy Variable Reluctance Actuators

PI(s): 

Ross Ian MacKenzie

Reluctance actuators can generate high force densities at small operating gaps, making them an attractive actuator technology for high-acceleration applications where low moving mass is critical, such as in photolithography scanners. However, their inherent nonlinearities present challenges for accurate control. These nonlinearities include nonlinear stiffness, magnetic hysteresis and saturation, and eddy currents. In this project, we focus on the modeling and control of these nonlinearities. We have designed a 1-DoF air bearing stage for testing a reluctance actuator prototype design and accompanying control algorithms. A particular focus has been placed on the modeling and control of magnetic hysteresis, and on force-linearizing the actuator through a high-bandwidth local feedback loop from a sense coil.