Part Orientation with a Force Field: Orienting Multiple Shapes Using a Single Field

In automated assembly, before parts can be put together, they often have to be appropriately oriented and positioned. The device performing this task is generally referred to as a part feeder. A new class of devices for non-prehensible distributed manipulation, such as MEMS actuator arrays, vibrating plates, etc., provides an alternative to traditional mechanical platforms for part feeding. These devices can be abstracted as programmable vector fields. Manipulation plans for these devices can therefore be considered as strategies for applying a sequence of fields to bring parts to some desired configurations. Typically, to uniquely orient and position a part, several fields have to be sequentially employed. In our recent work [18], we have shown that this objective can be accomplished using a single field. The work characterizes such a field for a given part. In this paper, we discover another interesting property of the field. In particular, we show that for a finite set of parts (with different shapes), we can specify a single field that can uniquely orient and position every part in the set. A force field device implementing this field therefore may be used as a part feeder for every part in the set without any reconfiguration.