Run-time interpretation of STEP-NC: implementation and performance

Abstract

This paper describes an experiment in building and running two STEP-NC interpreters for milling operations: one using ISO 14649, the other using AP 238 of ISO 10303. Both use STEP part 21 exchange files as input and call low-level machine control functions. Both include tool path generators and have sufficient functionality to execute the first example program at the end of part 11 of ISO 14649. The objectives and results were: (1) to determine if ISO 14649 and AP 238 contain sufficient information to run a machining centre (yes); (2) to determine whether AP 238 faithfully remodels the information in ISO 14649 for the functionality that was implemented (yes); (3) to determine whether real-time interpretation of STEP-NC is feasible (yes); (4) to determine the burden on systems programmers to build a STEP-NC interpreter (heavy); (5) to determine how interpretation time varies with file size (linearly for both interpreters); and (6) to compare the speed with which the two formats can be interpreted. Using currently available software tools, ISO 14649 can be interpreted significantly faster, but both interpreters are so fast that interpretation time is negligible compared with running time.

Enabling cognitive manufacturing through automated on-machine measurement planning and feedback

“…By providing the high-level information to machining systems, STEP-NC will not only eliminate the costly and inefficient process of data postprocessing, it will also establish a unified environment for the exchange of information between product design, machining process planning and inspections. It enables the realization of a closed, STEP-NC based machining process chain with data feedback and a consolidated data structure at each level [22,23]. Industrial use of STEP/STEP-NC has shown evidence of significant cost saving, higher quality, and reduced time-to-market.…”

The development of a new STEP-NC code generator (GEN-MILL)

“…Using currently available software tools, ISO 14649 can be interpreted significantly faster (Kramer et al 2006). A detailed indepth study with explanations of the differences between G&M code and STEP-NC and in what way is the STEP-NC better than G&M code has provided a better insight into the capabilities of both standards.…”

A framework for machining optimisation based on STEP-NC

“…The "what-to-do" information maintains its generic nature until the last moment when a Fig. 4 IDEF0 diagram for detailed design of optimisation module CAM system populates the process plan with native manufacturing information in order to generate a specific "howto-do" process plan (Wang et al 2007;Xu et al 2006;Kramer et al 2006). Generic machining tools and generic cutting tools conform to the data defined by ISO 14649 Part 111 (ISO 14649-111: 2001).…”