CLAMPING PLANNING IN WORKPIECE-FIXTURE SYSTEMS

摘要

This paper presents a general method for the determination of the optimal clamping forces including their magnitude and positions. First, we develop a locally elastic contact model to describe the nonlinear coupling between the contact force and elastic deformation at the individual contact. Further, a set of "compatibility" equations are given so that the elastic deformations among all contacts in the workpiece-fixture system result in a consistent set of rigid-body displacement of the workpiece in its global system. We define the minimum norm of the elastic deformation at contacts as the objective function, then, formulate the problem of determining of the optimal clamping forces as a constrained nonlinear programming problem, which guarantees that the fixturing of the workpiece is passive force closure. The proposed planning method of optimal clamping forces is illustrated with numerical example.