A DIGITAL ROBUST CONTROLLER FOR CUTTING FORCE CONTROL IN THE END MILLING PROCESS

In this work, a digital robust controller is designed via Quantitative Feedback Theory (QFT) to maintain a constant cutting force in the pre sence of parametric uncertainty for a time varying end milling process . The QFT controller is designed using the delta transform method for discrete systems. The controller is designed to limit the overshoot an d settling time of the cutting force levels over a range of cutting pa rameters. Models are presented for the cutting process and machine dyn amics including parametric uncertainty and these models are used to de velop a controller which meets given tracking and regulation, specific ations for all plant values. Experimental results are obtained by impl ementing the controller on a milling machine.