Sensor less evaluation for a computer numerical control machine tool slide level using an empirical mode decomposition method

Slide level has a lot of influence on computer numerical control (CNC) machine tool performance. The deterioration of slide level will result in torsional vibration of the feed-axis control system and lower CNC machine tool control precision. Hence, it is necessary to investigate evaluation technology for the slide level of CNC machine tools. In this article, a novel kind of sensorless evaluation method for machine tool slide level based on linear scale or motor encoder and AC servo motor current/output torque is proposed. To improve evaluation precision, a kind of filtering method based on empirical mode decomposition (EMD) technology is employed. The analysis results of the experiments show that it is simple, rapid, feasible, and reliable to use sensorless information for evaluating slide level based on the EMD method.