A novel approach to minimizing both position and orientation errors in 5-axis CNC milling near singularity points

Singularity points in five-axis CNC milling often cause unpredictable rotary-axis behavior, leading to abrupt rotations that degrade machining accuracy and may result in gouging—particularly in side milling, where small orientation deviations can produce noticeable surface errors. To address this problem, this study presents a method that jointly minimizes positional and orientational errors in the vicinity of singularities. The approach combines G-code block interpolation with an inverse-kinematics-across-singularity (IKAS) framework and incorporates a Maximum Allowed Feedrate (MAF) strategy constrained by rotary-axis velocity, acceleration, and jerk. Simulation and experimental results show that the proposed method reduces the peak orientation deviation by up to 86.5%, suppresses nonlinear TCP error by 91.2%, and improves local feedrate smoothness by over 53% near singular points. These improvements enhance the overall reliability of both end-milling and side-milling operations when machining through singular regions.