Advanced $X \theta$ Reluctance Electromagnetic Micropositioning System for Precision Motion Control

Abstract

This study examines a novel setup of a micropositioning trajectory manipulator in <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$X \theta$</tex>, energized by a reluctance actuator (RA) and two accompanying moving magnet actuators (MMA). The design is characterized by a C -core RA, which features asymmetrical air gaps between the mover and the stator elements when under angular <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\theta$</tex> rotation. When the stator coil is energized, a magnetic flux induces a force in the mover. Two MMAs can add force and torque dynamics to the system via solenoid and permanent magnet (PM) pairs to offer additional corrective actions. Facilitating control of a translational (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$x$</tex>) and rotational (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\theta$</tex>) two-degree-of-freedom (2DOF) actuation system. Flexure hinges aid in the retraction force of the mover element and provide needed stiffness to the system without frictional effects. This was modeled analytically and optimized to achieve outlined performance objectives. The system was validated experimentally through triangle, and sinusoidal trajectories in open loop control. The most relevant application is scanning mirror systems where specific targeted rotational and translational trajectories can benefit light beam positioning. This system allows both translation and rotation specifications of a selected trajectory to be realized in one actuation unit, opening up more design possibilities for controlling precision positioning systems.