Integrated Five-Axis Trajectory Shaping and Contour Error Compensation for High-Speed CNC Machine Tools

A feedforward trajectory command shaping algorithm is proposed to simultaneously reduce the contouring errors and avoid structural vibrations in five-axis CNC machine tools. Trajectory shaping is used to avoid the excitation of the transient, inertial vibrations but at the expense of distorting the reference path due to added delay. The contouring error caused by both trajectory shaping and limited bandwidth of servo drives is predicted based on the trajectory parameters and machine dynamics. The shaped axis commands are then corrected to precompensate the predicted contour errors. The effectiveness of the proposed technique is verified experimentally on a five-axis CNC machining center.