Modelling and adaptive pole assignment control in turning

Abstract A mathematical model relating feed rate to feed force is formulated in a turning process with the compliance of the machine tool taken into consideration. The model is used for the control of the feed force by a fixed gain PI and an adaptive pole assignment control algorithm. Effects of consideration of the structural compliance for the control model are investigated through stability analysis of the controlled system and a comparison study of the predicted and measured feed forces. It is shown that inclusion of the machine tool compliance into the control model enables predictions closer to the measurements of the stability and is hence desirable. The adaptive pole assignment controller is found to be stable with good performance characteristics over a wide range of operating conditions.