The application of STEP-NC using agent-based process planning

Computer aided part programming is an information intensive activity, and provides an interesting area for the application of artificial intelligence, knowledge-based systems and recently for agent technologies. Intelligent software agents can behave and respond autonomously to set criteria. The flexibility of agents and their ability to make autonomous/cooperative decisions makes them an excellent tool in the development of future computer aided process planning systems. In addition, a new ISO standard for NC machine tool programming is emerging called ISO 14649, informally known as STEP-NC. This standard is aimed to replace the existing ISO 6983 (G&M code) standard, which has been in use since the first NC machine tools were developed in the 1950s. STEP-NC does not describe tool movements but uses a higher-level language to define operations known as Workingsteps. A new breed of intelligent controller is envisaged to determine optimized tool trajectories allowing advanced inter-operability and a bi-directional information flow which allows edits made at the machine to be fed back to the CAD/CAM model. This paper presents a STEP-NC compliant computational environment used to demonstrate agent-based process planning, resulting in the generation of STEP-NC code. The system comprises a multi-agent framework, where agents represent the individual features of the component and work independently and cooperatively to generate process plans for discrete component manufacture. This is demonstrated through a series of case study components which evaluate various feature interaction scenarios.