STUDY OF THE CORRELATION BETWEEN SURFACE-ROUGHNESS AND CUTTING VIBRATIONS TO DEVELOP AN ONLINE ROUGHNESS MEASURING TECHNIQUE IN HARD TURNING

Surface roughness is one of the important factors in all areas of trib ology and in evaluating the quality of a machining operation. In order to achieve computer controlled machining in a flexible manufacturing system, a technique is needed for the on-line, real-time monitoring of each machining process parameter that affects surface roughness. As t he first step in developing such an algorithm, research on the correla tion between surface roughness and cutting vibration is reported in th is paper. The algorithm utilizes the relative cutting vibrations betwe en tool and workpiece, which are measured through an inductance pickup and filtered by an analog bandpass filter for a specific vibrational component. The cutting vibration signals of a specific frequency are s uperimposed onto the kinematic roughness, which is calculated by the t ool edge radius and feed rate. Experimental results show good correlat ion between the simulated roughness obtained using the proposed algori thm and the roughness actually measured with a surface profilometer.