Integration of in-process monitoring and statistical process control of surface roughness on CNC turning process
In order to realise an intelligent machine tool, the aim of this research was to propose an integration of the in-process monitoring and statistical process control (SPC) of the surface roughness during the turning process by using the cutting force ratio. The previously developed in-process surface roughness models of the author are adopted and employed to predict the surface roughness during the cutting with five factors of the cutting speed, the feed rate, the tool nose radius, the depth of cut and the cutting force ratio. The cutting force ratio is utilised to estimate the in-process surface roughness which is the ratio of the feed force to the main force. The dynamometer is installed on the tool turret of CNC turning machine to monitor the cutting force. The in-process SPC of the surface roughness has been developed and proposed to monitor and control the in-process predicted surface roughness from the adopted models by using the I-MR Charts. It has been proved by the cutting tests that the proposed and developed system of the in-process estimation and SPC of the surface roughness can be used to monitor the in-process predicted surface roughness by utilising the cutting force ratio with the high significance at 95% confident level.
monitoring statistical process control surface roughness turning cutting force ratio i-mr charts