Sheet Metal Bending Operation Planning Using

A large number of manufacturing operation planning problems can be formulated as state space search problems In case of sheet metal bending operation planning processing a search node involves extensive geometric reasoning Such computation intensive node processing limits the number of search nodes that can be expanded in a reasonable amount of time making it di cult to solve real life operation planning problems In this paper we describe a scheme to speed up operation planning by virtual gen eration of state space nodes In this scheme we eliminate unnecessary computation at the time of node generation by extracting the required information from already generated nodes Although generation of two di erent search nodes rarely involves identical computation steps there is considerable overlap in node generation steps We have divided the node generation step into a number of computation subproblems When we need to generate a new node we rst try to see if any of the node gener ation subproblems have been solved for any of the already generated nodes If any subproblem has already been solved for some other node then we use the solution of that subproblem to save computation time In such cases we do not perform node generation computation steps and therefore we call such node generation virtual The scheme presented in this paper increases the node generation capability and allows us to consider many more search nodes The ability to consider more search nodes helps us in solving more complex problems and nding better operation plans