Trap Design for Vibratory Bowl Feeders

The vibratory bowl feeder is the oldest and still most common approach to the automated feeding (orienting) of industrial parts. In this paper we consider a class of vibratory bowl filters that can be described by removing polygonal sections from the track; we refer to this class of filters as traps. For an n-sided polygonal part and an m-sided polygonal trap, we give an O(nm log n) algorithm to decide whether the part in a specific orientation will safely move across the trap or will fall through the trap and thus be filtered out. For an n-sided convex polygonal part and m-sided convex polygonal trap, this bound is improved to O((n+m) log n). Furthermore, we show how to design various trap shapes, ranging from simple traps to general polygons which will filter out all but one of the different stable orientations of a given part. Although the run times of our design algorithms are exponential in the number of trap parameters, many industrial part feeders use few-parameter traps (balconies, canyons, slots); in these cases the running times of our algorithms range from linear to low degree