Computer-aided process planning: Task representation and sequencing

Process planning is a combination of art and engineering concerned with organizing manufacturing operations to turn raw materials into a product. The computer offers the process planning task increased potential for standardization, optimization, and more rapid response to changes in part design or in the manufacturing conditions on the factory floor. This thesis investigates the representation and sequencing of tasks in process planning. Unfortunately, a large number of possible process plans can make finding efficient plans very difficult.;An algorithm is presented that acts as an oracle in determining the number of possible task orderings using a precedence graph representation for a set of tasks and precedence constraints. The Oracle uses three subgraph reduction patterns to find the exact number of possible task orderings for a class of N-fold graphs or an upper and lower bound on the number of orders for all other precedence graphs. An analysis of the Oracle algorithm shows that an exact answer or bounds on the number of possible orders is calculated in O(;A CAPP system for Concurrent Design and Evaluation (CDE) is proposed but not implemented. CDE takes advantage of the Oracle algorithm and two interactive design critics to help find efficient process plans. Although some components of the CDE system exist, others require additional research into difficult problem solving areas such as: path and grip planning, determining stability of objects, and incorporating inspection and testing into plans.;An Automated Assembly Planning with Fasteners (AAPF) system is described that uses geometric reasoning to derive feasible assembly sequences based on the geometric data present in a CAD model. AAPF is first automated assembly planning system to pay attention to individual fasteners. It automatically derives which components in a product are held together by which fasteners, and uses this connectivity information and the type, size, orientation, and location of fasteners to aid in determining efficient assembly plans.