Minimising temperature milling machinery errors
As industry has adapted to the ever-increasing utilisation of computers and their software, machine technology has striven for even greater levels of accuracy. However, one of the biggest causes for machining errors is due to temperature changes caused by the friction of machine tools. This problem therefore continuously drives R&D into developing higher accuracy solutions that can enhance machining performance, whilst at the same time reducing and eliminating machining errors. Some of the machining errors can be removed by changing the machine designs, however, others need to be controlled with the use of measuring devices and software error compensation methods. These activities comprise error measurement techniques, error modelling techniques and compensation algorithms, which combine into a workable approach for thermal management errors. The object of this process was to minimise the number of temperature sensors and increase the deformation equipment, which are pre-requisite components for CMM (Coordinate Measuring Machines). The software compensation methods are established over a period of time and work with a series of laser interferometer measurements, thus enabling temperature dependency of machine scales to be corrected. To provide added value for the research, during the next phase, the researchers devised a parametric model that corrects the thermal temperature displacements of the measurement probes during temperature fluctuations. The resultant efficiency was demonstrated within various tests on two different CMM, and this enabled the software correction technology to facilitate manageable thermal machining effects. With the assistance of an industrial partner, the researchers have been able to validate the feasibility developments and have also made suggestions for design improvements for CMM. These design improvements have already been implemented on new CMM's and the parametric model research results have been incorporated into industrial applications.