ABSTRACT
A common task in automated manufacturing processes is to orient parts prior to assembly. We address sen sorless orientation of a polygonal part on a conveyor belt by a sequence of stationary fences across this belt. Since fences can only push against the motion of the belt, it is a challenging problem to compute fence de signs which orients a given part. In this paper, we give several polynomial-time, algorithms to compute fence designs which are optimal with respect to various crite ria. We address both frictionless and frictional fences. We also compute modular fence designs in which the fence angles are restricted to a discrete set of angles instead of an interval
Many automated manufacturing processes require parts to be oriented prior to assembly. A part feeder takes in a stream of identical parts in arbitrary ori entations and outputs them in a uniform orientation. Part feeders often use data obtained from some kind of sensing device to accomplish their task. We consider the problem of sensorless orientation of parts, in which the initial pose of the part is assumed to be unknown. In sensorless manipulation, parts are positioned and/or oriented using passive mechanical compliance. The in put is a description of the part shape and the output is a sequence of open-loop actions that moves a part from an unknown initial pose into a unique final pose. Among the sensorless part feeders considered in litera ture are the parallel-jaw gripper [9, 13], a single push ing jaw [2, 14, 15, 17], a conveyor belt with a sequence of (stationary) fences placed along its sides [7, 18, 21], a conveyor belt with a single rotational fence (1 JOC) [1 ], a tilting tray [1 2 , 16], and vibratory plates and programmable vector fields [5 , 6].
