Monitoring Cutting Forces In Turning: A Model-Based Approach

Abstract

The importance of monitoring the cutting force in the turning process has been well recognized in industry as well as in the open literature. This paper proposes a cutting force monitoring approach that does not utilize force dynamometers but rather estimates the cutting force based on the spindle motor current and speed as well as a model that relates these measurements to the cutting force. Motor current and speed can not only be inexpensively and reliably measured but, in addition, can be shown, along with the properly chosen model for the model-based estimator, to accurately estimate the cutting force. This method is demonstrated on a CNC lathe and its advantages and limitations are discussed.