Expert System for Manufacturing Sequence Design of Axis-symmetric Cold Forging Products Using 'Constraint Blackboard'

Abstract

Authors suggest idea of 'virtual process' and 'real process', and use of 'constraint blackboard' for CAPP of combination forging process. A virtual process is a primitive and basic forming process, which may be only in the mind of a process designer. A real process is the set having virtual processes as its elements. When he designs forging process, he guess transit pre-form shape at each successive virtual process, and gathers up to one real process at last. These virtual processes restrict themselves each other in volume control, deformability, and ability of combination when they are gathered up. The authors research such virtual processes and their constraints, enter them in database, and implement expert system for axis-symmetric cold forging products using case-based reasoning and 'constraint-blackboard.' The system starts design from the final shape toward raw material. It fixes manufacturing plan at each virtual process. Once an virtual process is designed, its constraint is written on 'constraint-blackboard.' When next virtual process is designed, the process is examined by the system referring to 'constraint-blackborad.' Until the system fails to find a virtual process which is not inconsistent to past fixed virtual processes, it continues to get them together to one real process.