A tool orientation smoothing method for five-axis machining to avoid singularity problems

In numerically controlled grinding of aeroengine blades, a sharp change in a rotating shaft caused by a singular zone greatly reduces grinding precision and quality. This paper proposes an algorithm to optimize the tool-path that combines optimization of the C-axis rotation angle, a modification to the tool orientation and adjustments to the tool position by taking a four-array machine tool with two rotational axes (B-axis and C-axis) as an example. The algorithm was verified using VERICUT software, furthermore, in machining experiments, the rotation amplitudes of the rotary axis in singular areas was effectively reduced, which ensured grinding quality of blades.