Published online by Cambridge University Press: 26 September 2014
This work is interested to the analysis of the vibratory signals coming from a millingoperation. The objective is the detection of cutting tool breakage using thecyclostationary tools. Initially, we will show that the vibration signals captured fromthe milling operation are cyclostationary. The proposed cyclostationary methods are thefirst and second order synchronous statistics and the spectral correlation. A test rig,composed of a milling machine (cutter with 5 teeth) and a workpiece, is used to extractthe vibration signals that are angular sampled in the free fault case and one broken toothcase. This test rig is instrumented with three accelerometers, installed in the threedirections, and an optical encoder that allows the angular sampling. Then we will see thatthe angular sampling of the signals captured from a milling operation is essential topreserve the cyclostationary properties destroyed, in the case of the temporal sampling,by speed fluctuations. The proposed method capacity to detect the broken tooth is shown.The synchronous statistics of order 1 and order 2 detect the broken tooth presence and itsemplacement. The spectral correlation analysis distinguishes the broken tooth presence,but is not practical for the diagnosis. For that, an indicator based on the spectralcorrelation is proposed.