Position geometric error modeling, identification and compensation for large 5-axis machining center prototype

•A geometric error model is established for large 5-axis machining center prototype.•A virtual rigid-body method is put forward for calculating positioning error of each large translational axis•Analytical models based on least-squares theory are adopted to compute error values at an arbitrary position.•Recursive software-based error compensation method is used to compensate the position geometric errors.•Position accuracy of large machining center prototype has been improved with compensation and up to the design requirements.

This paper presents a position geometric error modeling, identification and compensation method for large 5-axis machining center prototype. First, regarding the prototype as a rigid multi-body system, a geometric error model has been established, which supports the identification of position geometric error associated with a translational axis by using laser interferometer, and a rotational axis by using laser tracker. Second, based on this model, an improved identification approach named as virtual rigid-body is put forward for calculating positioning error of each large translational axis. Detailed derivation of a generalized matrix equation is given. Third, analytical models based on the least-squares theory were adopted to compute error values at an arbitrary position for error compensation. Finally, the identified position geometric errors were compensated by using recursive software-based error compensation method. The results show that the position accuracy of large machining center prototype has been improved with compensation and up to the design requirements.