Part Orientation with Programmable Vector Fields: Two Stable Equilibria for Most Parts

L. E. Kavraki, “Part Orientation with Programmable Vector Fields: Two Stable Equilibria for Most Parts,” in Proceedings of The International Conference on Robotics and Automation (ICRA), Albuquerque, NM, 1997, vol. 3, pp. 2446–2452.


Part manipulation is an important but also time-consuming operation in industrial automation. Recent work explores alternative solutions to the mechanical parts feeders which have been traditionally used to sort and orient parts for assembly. One of the proposed alternatives is the use of programmable vector fields. The fields are realized on a plane on which the part is placed. The forces exerted on the part’s contact surface translate and rotate the part to an equilibrium orientation. Certain vector fields can be implemented in the microscale with actuator arrays and in the macroscale with transversely vibrating plates. Although current technology is still limited, the dexterity that programmable vector fields offer has prompted researchers to further explore their capabilities. This paper presents a vector field that can simultaneously orient and pose most parts into two stable equilibrium configurations. The equilibrium configurations are easily computed a priori given the part to be oriented. Our analysis makes no assumptions about the shape of the part or its connectivity except that it moves as a rigid body. The proposed vector field offers the great advantage of stability of the equilibrium configurations under small perturbations of the part which is key for the orientation of toleranced parts.


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