CAPP, Strategy and models in aircraft industry
Résumé
Unlike CAD and CAM systems have been used in industry for a long time, computer aided process planning systems are waiting yet in research laboratories to be transferred to industry. No unified method has emerged to generate process plans and parts layouts are very
diverse, making industrial CAPP systems difficult and expensive to be developed. Indeed manufacturers have to provide a significant effort to make their needs explicit and their own knowledge formalised in order to get CAPP software adapted to their methods and practice.
Our study contributes to generic research on CAPP systems. To meet the needs of aircraft industry, new approaches have been specified and developed for 5-axes parts. The originality of the study relates to the following points:
- The machining features are reduced to elementary faces. The manufacturability of these faces cannot be treated independently of the others, as in the preceding studies.
- Particular features, named “Critical Features”, identified and solved in early process planning, guide process planning strategy.
- Based on industrial rules, new Set-Up strategies should be defined.
This imposes a new formalisation of the machining features and their associated processes. In parallel, a model of activities is employed to generate the macro-process plan, adapted to aeronautical parts. The analysis and the formalisation of existing industrial methods bring
the necessary elements to guide and validate our research.