مشخصات قابلیت ابزار و ماشین آلات برای برنامه ریزی فرایند هوشمند

An optimized metal cutting process plan can only be developed with an accurate capability profile of a machine tool. Based on the information within this profile, a manufacturing decision making process can ascertain the time and production cost of parts. In this paper, a standardized methodology for modelling manufacturing resources is realized to enable accurate representation of actual resources and custom constraints. An example case study demonstrates the application of the machine tool capability profile through the selection of available cutting tools rather than using nominal cutting tools.

Process planning for metal cutting is among the most knowledge-intensive activities in manufacturing. In this activity the product information is mapped on to the available information for the various existing manufacturing resources to determine a plan of action to convert the raw material into the final product [1]. This activity is currently supported by information technology in the form of computer aided process planning [2]. A considerable amount of research has been carried out to introduce more intelligence into process planning [3]. Process planning relies on manufacturing resource models to supply the necessary information regarding the physical devices used for manufacturing [4]. In the state of the art, the nominal model of manufacturing resources is used for process planning. The information contained within this model, neither reflects the actual state of the resources, nor does it reflect any policy constraints that have been implemented in the manufacturing enterprise. This results in generation of process plans that might not be entirely effective in the context of the available resources and policies. In this paper a STEP-compliant methodology for representing resources is extended to allow the representation of machine tool capability profiles in a time-based manner while enabling users to define custom rules and policies. The extended data model can support the information requirements for profiling techniques such as prediction and online monitoring of resources as chosen by the user. The advantages of the methodology and the augmented model are then presented through the use of a case study. A discussion on the possible implementations of the methodology is then presented together with the conclusions derived from the work.

Through the use of manufacturing resource capability profiles, it is possible to optimize the generation of the process plan to develop solutions that are appropriate for the actual available hardware and software rather than the nominal values. Capability profiles are generated by combining the nominal resource models with actual values obtained from sensors on the shop floor and predictive models. Although any nominal resource model can be utilized for this purpose, the use of a standardized resource model would substantially increase the breadth of the applicability of the resource capability profiles. With capability profiles, it is also possible to implement production policies during the generation of process plans, thus saving time and effort in comparison to implementing them afterwards on the shop floor. This results in an increase in trust throughout the process planning activity and leads to the generation of verified process plans.