Modular conveyor system having multiple moving elements under independent control

摘要

The invention relates to conveyor systems. This application is a divisional application of EP-A-1 015 851 and relates specifically to a modular conveyor system comprising a number of interconnected track sections forming a substantially continuous track, wherein each track section comprises a stator armature having a plurality of individually controllable coils disposed substantially along the entire length of the track section; a plurality of moving elements travelling separately and independently along the continuous track, each moving element having at least two thrust producing magnets arranged in alternating North and South sequence and disposed face to face with the stator armatures of the track sections; a number of track section controllers, one per track section, for regulating and commutating the coils of the corresponding stator armature in order to produce a separate moving MMF for each moving element located in the corresponding track section and independently control each moving element located therein; and communication means for interfacing the section controllers of adjacent track sections, wherein a given section controller is operative to utilize the communication means in order to transfer a servo responsibility for resolving the position of a given moving element to an adjacent section controller when the given moving element straddles the corresponding track sections, and wherein each of the given and adjacent section controller pair provides at least one coil regulating signal to the other of said pair in the event any portion of the magnets of the given moving element spans any portion of at least one coil situated in the track section corresponding to the other of said pair, provided that the responsibility for resolving the position of the given moving element has not yet been transferred to the other of said pair.