Research On The Key Technologies In MES For Sheet Metal Cutting

The MES (Manufacturing Execution System) for sheet metal cutting is an optimal system which can optimize cutting plans, optimize nesting layouts of sheet metal parts, optimize cutting processes, and monitor the status of cutting production and manage the related data and documents, etc. The system can improve the efficiency of cutting production and augment the ratio of sheet plates'utilization. Therefore the management level of the enterprises with sheet metal cutting production can be enhanced and the costs can be decreased. This thesis presents a research on key technologies in MES for sheet metal cutting and the main contents are as follows:First, the functional goals of the MES for sheet metal cutting are defined according to the requirements of cutting production. The functional structure of the system and the network architecture based on C/S are designed. Then the system is divided into several subsystems which include plans optimizing, layouts optimizing, status monitoring and data and documents managing, etc. The functions of each subsystem are defined.The structure of plans optimizing subsystem is established based on the analysis of production process model (PPM). The basic developing process of the subsystem is well designed and analyzed. In the research of the method which optimizes plans with the consideration of layouts optimizing, a model is constructed to depict the problem and the solutions are generally made.The overall functional structure of layouts optimizing subsystem is designed and the related algorithms are introduced. By converting multi-plates nesting problem into the continuous plate nesting problem, the batch nesting for plans optimizing is researched. Then the Weiler-Atherton graphics clipping algorithm and a tentative prune-and-search approach are introduced to solve the problem of local area filling. And a heuristic algorithm based on the features of graphics of sheet metal parts is presented, with which the cutting path optimization on layouts is researched and developed.Finally, the network architecture of subsystem of cutting status monitoring is designed. The functions and the methods of data management subsystem are analyzed. And the document management subsystem is designed and its contents are defined.