Abstract: Based on MBS (Multi-body system), an error model is presented here for the thermal errors in machining centers as well as the related compensation method. Taking three-axis MAKINO machining center as an example, a specific error model is set up through theoretically analyzing and experimentally parameter-identifying. Four temperature sensors are selected after optimization, and the temperature changes from their readings offered as the inputs to the error parameter models. Then a real-time software compensation is carried out, a set of small surfaces are cut on the machining center along the x, y and z-axis with and without error compensation. The measurement results from CMM show an obvious improvement is obtained after the real-time compensation. Thus the facts above verified the validity and feasibility of this error model and compensation method.

Key words: Compensation technique, Machining center, Multi-body system theory, Thermal error