ADVANCED THERMAL ERROR COMPENSATION OF A FLOOR TYPE MACHINING CENTRE ALLOWING FOR THE INFLUENCE OF INTERCHANGEABLE SPINDLE HEADS

Abstract

This paper is a continuation of scientific work on the modelling of complex MT thermal behaviour using a dynamic method with a physical basis: thermal transfer functions. Previously published works focusing on middle-sized MTs are extended here to include heavy-duty MT application. Particular attention is paid to issues concerning compensation of thermal errors caused by interchangeable spindle heads. The inputs of the compensation algorithm are the spindle rotational speed and the 3 temperatures of the machine structure. A reduction of thermal errors achieved by using the new approximation TF model including MT in basic configuration and configuration with spindle head is up to 86% with significant reduction of the time necessary to calibration conducted directly on a complete MT assembly.