Research on Online Process Planning for CNC Machining in Holonic Control Architecture

Holonic control architecture is one of the most advanced control modes for intelligent manufacturing system. Based on this mode a process planning control architecture is developed for CNC machining in this paper. The architecture is divided into three parts, i.e. on-line, off-line and real-time process planning. Then the on-line part with multiple decision objectives is mainly considered and discussed. Further a combined algorithm based genetic algorithm (GA) and metamorphic greed heuristics (MGH) is proposed to find a solution for the planning. The hybrid algorithm realizes eliminating OR nodes and sequencing AND nodes from AND/OR graph used to represent a process plan. In the algorithm, a data containment tree structure is applied to convert the graph to be available for GA chromosome coding. In calculation of the individuals´ fitness value, a heuristic relation matrix is provided to determine heuristic paths according to the tree. In the end, an illustration is presented to test the applicability of the proposed approach. The developed methodologies can help decision-makers improve process planning level in dynamic CNC machining circumstances