# TRAP DESIGN FOR VIBRATORY BOWL FEEDERS

### Ken Goldberg

UC Berkeley

### Abstract

The vibratory bowl feeder is the oldest and still most common approach to the automated
feeding (orienting) of industrial parts. In this talk 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 convex polygonal part and m-sided convex polygonal trap, I'll describe
an O((n+m) log (n+m)) algorithm to decide if the part will be rejected by the trap, and an
O((nm)^{2+e}) algorithm which deals with non-convex parts and traps. We then consider the
problem of designing traps for a given part, and consider two rectilinear subclasses,
*balconies* and *gaps*. I will describe linear and O(n^2)
algorithms for designing feeders.

We are developing an online Java applet to demonstrate the design algorithms. I'll
demonstrate and show video of physical experiments using a commercial inline vibratory
feeder. We are not aware of any previous algorithms for the systematic design of vibratory
bowl traps.

(This is joint work with R-P. Beretty, M. Overmars, and F. van der Stappen at U.
Utrecht)

Ken Goldberg (goldberg@ieor.berkeley.edu) is Assoc. Professor of Engineering at UC
Berkeley. He received his PhD in 1990 from the School of Computer Science at Carnegie
Mellon University. Goldberg and his students study geometric algorithms for feeding,
sorting, and fixturing industrial parts. He was named a National Science Foundation Young
Investigator in 1994 and NSF Presidential Faculty Fellow in 1995. He is currently editing
a book on Internet Telepistemology for MIT Press. For more information please see: www.ieor.berkeley.edu/~goldberg.

Edited by Leonidas Guibas