Generative Process Planning with Reasoning Based on Geometrical Product Specification

The focus of this paper is on CAPP for parts manufacture in systems of definite process capabilities, involving the use of multi-axis machining centers for parts shaping and grinding machines for finishing. It presents in particular a decision making scheme for setup determination as a part of generative process planning. The planning procedure consists of two stages. The first stage is associated with generic setup determination applying tool accessibility analysis to machined features and reasoning based on geometrical product specification (GPS). The second stage involves machine specific setup planning considering the availability and capability of machines on a shop floor through setup merging. The impact of dimensional and geometric tolerance as well as the surface roughness of relatively complex mechanical element on the generated process plan with several setups was presented. The relevant reasoning mechanism within a decision making scheme on generated process alternatives is shown based on a numeric case.

Fixture-Based Usefulness Measures for Hybrid Process Planning

This paper describes a usefulness measure that supports ongoing work on a hybrid process planning approach that combines the best characteristics of both variant and generative process planning while avoiding their worst limitations. To specify the fixtures needed by a process plan for a new design, the hybrid approach must identify existing designs and process plans that have fixtures that can hold the new design. Because traditional geometric similarity measures are inadequate, we have developed a new fixture-based usefulness measure.