Feature-Based Process Planning in the AMRF

The growing use of "features" in the design and manufacturing communities is due to the fact that features better capture the functionality or intent associated with a part design. The process planning team at the National Bureau of Standards is using features and their associated functionality to derive process plans from a part model in a semi-automatic fashion. The process planning team believes that features are the key to having a fully automated planning system. This paper will discuss the feature-based process planning work currently in progress at the AMRF. Before the current work is described, background information will be given on the AMRF, process planning in the AMRF, some existing definitions of a feature, how the process planning team defines a feature, and current research in the field of features. I. INTRODUCTION The use of "features" is a recent approach to the old problem of attempting to link CAD with CAM. The features approach constrains the designer/process planner to working with a set of features which have significance for either design, analysis or manufacturing. Instead of using a model consisting of graphics primitives (e.g., lines, circles, points), the designer/planner is asked to use a set of features (e.g., holes, pockets, slots) from which manufacturing operations can be derived. When both the designer and process planner have finished the design and process plan, more information has been entered into the model than if the part had been created on a traditional CAD system. However, the designer and planner have entered the information not at the geometric level but at a higher level. The process planning team of the Automated Manufacturing Research Facility (AMRF) has proposed and is currently building a process planning system which is based on the use of features. The new system will capture more manufacturing knowledge from both the designer and process planner. The ultimate goal of the process planning team is to completely automate the planning for manufacture of a part. The current goal of the project is to produce a process plan from a design representation containing geometry, topology, datum, tolerance, and features information. The process plan will contain references to: manufacturing features, setup information, tool selections, and sequencing of steps for the production of the part. This paper will discuss the feature-based process planning work currently in progress at the AMRF. Before the current work can be described, background information will be given on the AMRF, process planning in the AMRF, some existing definitions of a feature, how the process planning team defines a feature, and current research in the field of features.