Computing fence designs for orienting parts

A common task in automated manufacturing processes is to orient parts prior to assembly. We consider sensorless orientation of a polygonal part by a sequence of fences. We show that any polygonal part can be oriented by a sequence of fences placed along a conveyor belt, thereby settling a conjecture by Wiegley et al. [17], and present the rst polynomial-time algorithm to compute the shortest such sequence. The algorithm is easy to implement and runs in time O(n logn), where n is the number of vertices of the part.