From an industrial point of view, the milling of 2.5D cavities is a frequent operation, 1
consuming time and presenting optimization potential, especially through a judicious choice of 2
the tool trajectory. Among the different types of trajectories, some have a general spiral-like aspect 3
and can potentially offer a reduced machining time. They are called curvilinear trajectories and are 4
obtained by interpolation between structure curves which are the numerical solutions of a partial 5
differential equation. In this case, the machine tool will connect points and the trajectory will be made 6
up of small segments. Even if, macroscopically, these trajectories have all the qualities to allow the 7
tool to move quickly, on a small scale, the discontinuities in tangency, inherent in the discretization, 8
significantly increase machining time. This article suggests to enhancing the continuity level of the 9
toolpath by rebuilding structure curves with a set of Hermite quartic spline patches connected in 10
tangency and curvature. Thanks to this, the tool will machine at an average feedrate closer to the 11
programmed one and will, de facto, reduce traveling time. 12
This article shows that the proposed method increases, on the two tested cavities, toolpath quality 13
indicators, reduces milling time from 10% to 18% for a curvilinear method without a filter and make 14
it possible to generalize the Bieterman and Sandström method for all non convex pockets.