Active Compensation of the Deformation of a Magnetically Levitated Mover of a Planar Motor

The paper describes a commutation method used for the active compensation of the deformation of the magnetically levitated mover of a planar motor. The single-stage double layer planar motor under consideration comprises a stator with two coil arrays and a mover with permanent magnets, and is designed to perform positioning tasks with high accuracy. To minimize the deformation of the light-weight moving structure, which is exposed to a large force during actuation, its flexible behavior is considered in the commutation of the machine. The commutation decouples the rigid-and flexible-body modes and calculates the required currents in the coils to produce a desired force and torque, as well as the modal force to control the flexible modes deformation. To decouple the flexible modes in the commutation, the relation from coil current to deformation is required, which is obtained by the coupling of a mechanical model and electromagnetic model of the motor. Using a 25-axis laser interferometer system, the deformation of the mover is measured and the relation from coil current to modal deformation is experimentally validated. In a second experiment, the deformation reduction of the magnetically levitated translator is demonstrated.