Overcoming synchronization challenges in machining digital twins: transpiling legacy NC dialects to enhance interoperability

Abstract Digital Twin (DT) technology is a key enabler of smart manufacturing, with extensive research devoted to virtual replicas of physical assets in both subtractive and additive processes. In this context, numerical control (NC) programs are central to synchronizing physical and virtual twins, yet they are typically based on G-code, a low-level language introduced in the 1960s. Although standardized at its core, G-code has been widely extended by CNC system developers, leading to multiple dialects and significant interoperability issues across heterogeneous machines. These differences hinder effective synchronization, particularly due to the difficulty of aligning timestamps among NC programs. This study proposes a methodology to improve synchronization and interoperability by transpiling NC dialects into a higher-level abstraction based on a comprehensive and fine-grained set of machining functions. The methodology is implemented as an extensible object-oriented framework. Validation through the successful transpilation of a legacy NC dialect demonstrates the ability to compute accurate event timelines, providing a foundation for the development of robust Digital Twins for G-code-based manufacturing processes.