An efficient online geometric simulation algorithm for real-time CNC machining process based on look-ahead method

Abstract

Intelligent CNC machining requires advanced online geometric simulation to improve transparency and optimize machining processes. The simulation algorithms need to be efficient enough to keep up with machine tool motions. However, traditional algorithms, which typically discretize the entire blank initially, often result in redundant computations, hindering efficiency in online environments. To strike a balance between efficiency and accuracy, this paper presents an efficient online simulation algorithm with three key innovations. First, the algorithm incorporates the concept of look-ahead into geometric simulation to pinpoint workpiece areas likely to contact the cutting tool. Second, it employs a dynamic voxel partitioning mechanism that adapts to the cutting tool’s movement, reducing data structures and eliminating redundant computations. Third, a hybrid modeling approach integrates voxel model spatial indexing with Tri-dexel model Boolean operations, enabling rapid local positioning and efficient micro-structural representation of the workpiece. Additionally, the algorithm is further optimized in key stages such as online interpolation and surface reconstruction. This algorithm has been integrated into several online simulation software systems and tested and validated on multiple typical 3/5-axis workpieces. Actual machining experiments confirm its efficiency, with over 99% of simulation computation times below 10 ms, meeting the requirements for online environments. The algorithm also demonstrates excellent performance in simulating large-scale aerospace workpieces, providing a solid foundation for real-time synchronization of geometric and physical parameters.