Feed-axis gearbox condition monitoring using built-in position sensors and EEMD method

This paper describes a kind of feed-axis gearbox condition monitoring system using the built-in position sensors such as motor encoders and linear scales with high resolution and high precision, which is more directly related to machine dynamics and is sensitive to the early and weak fault. To obtain the position information, several data acquisition approaches for open numerical control systems (NCs) and commercial NCs are suggested. Then, the mathematical models between the faults and the position signals are thoroughly investigated. Finally, the ensemble empirical mode decomposition (EEMD) method is introduced to localize the fault of the feed-axis gearbox. The experimental results show that it is effective to use built-in position sensors and EEMD method for on-line monitoring the gearbox state and fault diagnosis. (C) 2011 Elsevier Ltd. All rights reserved.