METHOD FOR CONTROLLING THE NORMAL FORCE OF A TRANSPORT UNIT OF A LONG STATOR LINEAR MOTOR

摘要

To reduce mechanical loading due to guidance of the transport unit of a conveyor installation in the form of a long stator linear motor and nevertheless ensure safe retention of the transport unit on the conveyor track of the conveyor installation in all operating conditions, the normal force (F_Nn) is controlled with a controller (Rk) for controlling the normal force (F_Nn). The controller (Rk) determines a normal-force-forming current component (i_And) of the drive current (i_An) of the drive coils interacting with the transport unit (Tn) so that a resulting normal force (F_ΣNn) acting on the transport unit (Tn) as the sum of the normal force (F_Nn), a magnetic force (F_Mn) in the normal direction (N) caused by the drive magnets, and an external force (F_En) in the normal direction (N) acting on the transport unit (Tn) corresponds at least to a specified retaining force (F_Nnmin) in the normal direction (N).