VIRTUAL METROLOGY SOFTWARE TOOLS AND TECHNIQUES FOR FEATURE EXTRACTION OF SPIRAL BEVEL GEAR ERRORS

ABSTRACT The main objectives of multi-axis machining are to achieve perfect surface quality, precision, and speed without any need for re-machining. Within cutting processes, a strong integration of technologies such as virtual machining and inspection algorithms is important [1]. Closed Loop Machining (CLM) is an important method to maximise the efficiency of cutting processes, and automatic data collection and inspection of the part to be machined are essential elements for continuous improvements [2]. This is especially true for free form shaped parts, which are often machined under extremely tight tolerances, as free form functional surfaces often have a great influence on the performance of a product [3]. As online inspection of parts is often not possible to the required accuracy, offline CMM inspection is used to collect the measured data of the free form part. However, in order to close the loop between inspection and re-machining, understanding the error sources of the part to be re-machined is essential. The main focus of this work is to develop a virtual metrology software tool, and associated techniques, to allow the correct identification of 5 axis machining error sources of spiral bevel gears. The virtual metrology platform has been developed based on the open source ‘ParaView’ software, and involves creating an extensive error library by virtually modifying gear parameters. These error sources, once understood, can then form part of an adaptive machining process to allow for the reduction of machining uncertainty, and an increase in part quality.