Dynamic behaviours of driving torque of machine tools in microscopic motion

Purpose: This paper presented more details for control analysis of the dynamic behaviors of the feed drive systems that have been widely used in machine tools. Design/methodology/approach: In order to analyze the nonlinear behaviors of the feed drive system in microscopic motion, the dynamic driving torques were measured when the sinusoidal waves of the microscopic displacement are applied to the AC servo motor. Findings: The experimental results showed that the distortion of the driving torque responses to the sinusoidal wave input of the microscopic displacement become gradually evident as the input amplitude increases. It was evident that the driving torque depends on the input amplitude, but not the input frequency. With the particular input amplitudes of 5um and over, it was clear that the trajectories for different initial driving torques show the same patterns. Research limitations/implications: The results of this research covered the feed drive system with the AC servo motor and rolling guide. However, because the dynamic behavior the rolling element was analyzed, it was alse applicable the feed drive system with the linear motor and rolling guide. Practical implications: This paper cleared more details of driving torque in(at) microscopic motion, the performance of the feed drive system with rolling elements would be improved. Originality/value: The objective of this research project was to develop the feed drive system with the one mechanism and with the high accuracy.