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

— 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 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...

• Type: Conference
• Year: 2005
• Where: ICRA
• Authors: Yizhar Or, Elon Rimon
• Keywords: External Wrench, Feasible Equilibrium Postures, ICRA 2005, Robotics, Robust Equilibrium Postures