Algorithms for grouping machining operations and planning workpiece location under dynamic machining conditions

In this paper, algorithms are presented to develop an integrated system to generate machining groups for set-ups and to plan workpiece location layout s for fixture design. The objective of the proposed system is to overcome t he deficiencies of existing set-up planning and fixture design approaches. Parts are described in terms of machining features that consist of attribut es required for automation and integration. The approaches of machining fea ture-based design and precedence matrix algorithm are combined to automate the process-planning task and to generate the machining groups for set-ups. An algorithm for selecting the locating and clamping positions of the work piece is presented to configure the fixture in terms of modular elements. F ixture configuration verification analysis is carried out for time-varying machining forces to ensure that the workpiece will be held against cutting and clamping forces. The chip-removal effect is taken into account for stab ility analysis using finite-element analysis technique. An example is inclu ded to illustrate the application of proposed system.