Identification of the Normal Force Response to Feed Input in a Turning Operation

Force is often used as the feedback signal in process control systems, while feed (or feedrate) is the controlled machining variable. The normal force is directly related to the chip load, which is proportional to the feed. Experiments were designed to observe the force response to step changes in commanded feed. An empirical dynamic model of the cutting process was developed relating actual feed to the normal cutting force. This process model is independent of the drive dynamics The parameters of a first order ARX model structure were estimated using recursive identification techniques.