Heuristic Machining Process Planning of a Toleranced Handle Based on Graph Inference

This paper investigates the methodology for fast machining process planning that satisfies part tolerancing specifications through the example of a handle. The method first maps each feature of a part into feasible finishing processes that are capable to achieve the specified tolerances and surface requirements associated with the feature. All possible process plans are then developed by expanding preceding processes of each finishing process. A directed graph, with processes as nodes and process sequence as links, is employed to represent the expanded machining processes. Process clusters with same specifications can be further merged and pruned to reduce the computational complexity of the graph. Each possible plan of the merged results is further integrated based on machining sequences. As there are often many feasible plans for machining a part, the qualified plan that satisfies design specifications is achieved by traversal through the graph. The procedure for machining process plan of the handle by such graph-based inference techniques is demonstrated in the paper. The merit of this method is to employ a unified graph model for representing and to reduce the complexity of the process plan efficiently based on inference on the graph.