Adaptive Cutting Force Observer for Machine Tool Considering Stage Parameter Variation

Abstract

Monitoring cutting force generated during the machining process is crucial to prevent tool breakage and chattering. The cutting force observer, which considers the machine tool as the two-inertia system, has been proposed to estimate cutting forces in wide bandwidth using multiple encoders. However, modeling errors and the parameter variation during machining can deteriorate estimation accuracy in such a model-based observer. Previous studies solved some modeling error issues, but inertia, friction, and other parameters that belong to the moving stage had rarely considered. Therefore, the adaptive cutting force observer is proposed in this paper. The proposal consists of online stage parameter identification and updating algorithm. The effectiveness of the proposed adaptive observer is demonstrated through the experiments using the simplified experimental setup.