Model based commutation containing edge coils for a moving magnet planar actuator

An extension of a special analytical commutation method for long-stroke magnetically levitated moving magnet type planar actuators is presented. It enables the use of coils that are influenced by the end-effect of the Halbach magnet array. They are located near the edge of the magnet array and are referred to as edge coils. The method adds those coils to the commutation correcting for the end-effect by modeling it as a multiplicative error in the commutation. As a result thermal losses are decreased while the error in the commutation is kept in the same order of magnitude. Experiments support the results