A general strategy to determine geometrically valid contact formations from possible contact primitives

A general strategy is presented to determine the geometrically valid contact formations (CFs) from a given set S/sub pc/ of possible principal contacts (PCs) between two arbitrary polygonal objects in the presence of location uncertainties. For any (non-empty) subset of S/sub pc/, the strategy tests if the PCs in the set form a possible CB by analyzing the geometrical contact constraints. The obtained set of geometrically valid CFs can serve as input to a verifier based on force sensing which will identify the actual CF occurred. Our analyses of contact constraints are complete and general. The results demonstrate that despite uncertainties in object locations, if two or more PCs are formed between two objects, their relative location in many cases is fixed or can take up to only 4 solutions. In such cases, we can accurately identify a valid CF. From a different perspective, these results could also be useful in grasp planning. Our future work includes taking into account modeling uncertainties of objects and extending this method to three-dimensional objects.