A new mechanism design of electro-magnetic actuator for a micro-positioner

This paper proposes a new type of non-conventional electro-magnetic actuator (EMA) for micro-positioning. It is a repulsive magnetic system consisting of a motion pad and two active coils. The motion of the pad is caused by the repelling force between the coils and the permanent magnets on the pad. First, the dynamic model is derived and analyzed. Next, an adaptive sliding mode controller is developed to deal with the unknown parameters with the objective of precision positioning. The experimental results demonstrate satisfactory performances including regulation accuracy and control stiffness for the system.