Milling gate vibrations analysis via Hilbert-Huang transform

¹ AGH University of Science and Technology, Faculty of Mechanical Engineering and Robotics, Department of Process Control, Mickiewicz Alley 30, 30-059 Krakow, Poland
² AGH University of Science and Technology, Faculty of Mechanical Engineering and Robotics, Department of Robotics and Mechatronics, Mickiewicz Alley 30, 30-059 Krakow, Poland

^* Corresponding author: g.litak@pollub.pl

Abstract

The study aimed at identification of the milling gate modal parameters: natural frequencies and mode shapes, in order to establish the working range free from resonant areas. The evaluation was performed under exploitation loads, generated in the course of the milling process. System responses, in the form of the acceleration time histories, were analysed with the application of the Hilbert-Huang method data analysis. Selection of this method was motivated by the fact that it does not require stationarity of the analysed and provides information about nonlinearities in vibration empirical modes. In contrast to classical nonlinear system identification methods, the Hilbert-Huang method does not require measurements of excitations acting on the system of interest nor linear system dynamic behaviour in a broad frequency range around any operating point.