No abstract

Over the last 50 years the development of CNC machines has seen a plethora of part programming languages. These programming languages have provided major barriers for the interoperability of information between CNC machines and Computer-aided (CAx) systems. Thus the process knowledge in existing part programs cannot easily be recycled and reused, due to an inability to interpret these forms of data. In fact, the process knowledge in the existing part programs is vital to develop process plans for new products, reduce leading time, and accumulate knowledge to enhance the product quality based on previous knowledge. In this paper, a STEP standard compliant method is proposed to recycle manufacturing knowledge from shopfloor in a universal manner. An EXPRESS model of CNC programming languages has been developed, though which different programing dialects can be translated into neutral data model. Based on the neutral data, a process comprehension method was used to capture process knowledge from CNC part programs and represent the knowledge in a standardised format. The EXPRESS model also forms a basis for a comprehensive machine tool modelling to assistant process planning activities. The proposed method is implemented in a prototype system and an industrial inspired component is used to validate the knowledge capture method.

Decision-making models for manufacturing technologies are becoming increasingly complex due to on-going rapid developments in additive and subtractive (Addtractive) manufacturing. Decision-making in manufacturing technologies should be based on machine and resource capabilities. Currently, multi-process manufacturing models have many shortcomings when describing machining capabilities, and in some cases, modelling approaches used in decision-making are ambiguous and poorly constrained. In this research, a formal modelling approach is proposed to facilitate modelling of machining capability and associated Addtractive operations. This mathematically based formal method allows system properties to be described in a well-defined manner. The ISO-standardised Z notation (named after Zermelo-Fraenkel set theory) has been utilised to build a state-oriented formalism model for machining capabilities and associated operations.