Hierarchical planning for multi-contact non-prehensile manipulation

Manipulation planning involves planning the combined motion of objects in the environment as well as the robot motions to achieve them. In this paper, we explore a hierarchical approach to planning sequences of non-prehensile and prehensile actions. We subdivide the planning problem into three stages (object contacts, object poses and robot contacts) and thereby reduce the size of search space that is explored. We show that this approach is more efficient than earlier strategies that search in the combined robot-object configuration space directly.National Science Foundation (U.S.) (grant 1420927)United States. Office of Naval Research (grant N00014-14-1-0486)United States. Air Force. Office of Scientific Research (grant FA23861014135)United States. Army Research Office (grant W911NF1410433

Stably Supported Rotations of A Planar Polygon With Two Frictionless Contacts

Explores the use of stable support in robotic manipulation. Stable support describes any contact configuration which balances a known applied force and is stable with respect to small perturbations in the handled object's pose. Specifically, the authors address the problem of manipulating a planar polygonal object in a fixed gravitational field, stably supported by two frictionless contacts. Representing each contact configuration as a force focus point defined by the intersection of the lines of action of the contact forces, the authors derive geometric regions of permissible force focus points for contacts on each pair of polygon edges. Each permissible force focus point maps to a unique configuration of the object and contacts in stable equilibrium. In turn, paths in the space of permissible force focus points map to real space motions of the contact points which induce quasi-static rotations of the object. The authors also present two graph search based strategies for planning hand-offs between pairs of contacts, thus enabling larger rotations than can be executed by a single contact pair. Finally, the authors describe an implementation of one of these planner

Grasp gaits for planar object manipulation

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1997.Includes bibliographical references (p. 97-98).by Susanna Richmond Leveroni.Ph.D