Computation and Graphical Characterization of Robust Multiple-Contact Postures in 2D Gravitational Environments

Y. Or, E. Rimon
Proceedings of the 2005 IEEE International Conference on Robotics and Automation  
This paper is concerned with the problem of identifying robust equilibrium postures of a planar mechanism supported by fixed frictional contacts in a twodimensional gravitational field. The complex kinematic structure of the mechanism is lumped into a single rigid body, B, with a variable center of mass. Inertial forces generated by moving parts of the mechanism are lumped into a neighborhood of wrenches centered at the nominal gravitational wrench. The identification of the robust equilibrium
more » ... robust equilibrium postures associated with a given set of contacts is reduced to the identification of center-of-mass locations that maintain equilibrium of B with respect to any wrench in the given neighborhood. The static response of B to an external wrench involves static indeterminacy and frictional constraints. The region of center-of-mass locations that generate equilibrium with respect to a particular external wrench is formulated as a linear programming problem, and a full graphical characterization is provided. The result is then generalized to robust equilibrium postures that resist a neighborhood of external wrenches. Finally, we present experimental results that validate the criteria for feasible equilibrium postures.
doi:10.1109/robot.2005.1570127 dblp:conf/icra/OrR05 fatcat:ujlhqomdnfhf5j2tnuc4a2rw54