Geometric reasoning for re-allocation of supporting and clamping positionsin the automated fixture design system

Geometric reasoning is an indispensable part of an automated fixture design system. This paper introduces a rational approach based on the use of both qualitative and quantitative reasoning tools to plan for the "best" suppor ting, locating and clamping positions (on a given workpiece) to hold the wo rkpiece rigidly and accurately during machining processes. It discusses gen eral algorithms to verify the preliminary fixture configuration, as obtaine d by using 3-2-1 locating rules against workpiece deformation and workpiece -tool interference, and to re-allocate the locating positions, if necessary . The paper also addresses the issues of implementing the algorithm in a pr ototype, automated fixture design system.