Realization and performance evaluation of a machine tool vibration monitoring module by multiple MEMS accelerometer integrations

The quality of machined products is largely dependent on the status of machines in various aspects. Vibration status monitoring is a fundamental step for reliability evaluation, machine fault diagnosis, and prognosis. For achieving such a task, miniature low-cost but effective sensors such as MEMS accelerometers should be used. However, due to the nature of machine tool characteristics, both high sensitivity and bandwidth are required and this imposes a challenging constraint on current MEMS devices. In this work, a tri-axial module by integrating three types and totally five MEMS accelerometers is designed and realized as the first step to realize the measurement module for machine tool applications. The performance of the module has been validated by a piezoelectric accelerometer, and the result indicated that the outputs of the proposed design essentially agree with those obtained by the standard piezoelectric accelerometer very well. Finally, the module has been applied on both a five-axis milling machine and a six-axis robot arms for detecting the process-induced vibration for demonstrating its possible applications in both abnormal condition monitoring and machine prognosis. In the near future, the performance will be improved by reducing noise and the size would be further reduced for fitting into critical location of machine tools.