Multiple-point vibration testing with micro-electromechanical accelerometers and micro-controller unit

A two-point vibration measurement system with bandwidth of 500 Hz has been constructed using low-cost standardized components, including MPU-6050 microelectrical-mechanical system (MEMS) accelerometers and a microprocessor unit. Methods to tackle sampling frequency stability and jitter in the proposed system are described. Compared with the upper frequency limit of 15 Hz in previous studies, operating deflection shapes (ODSs) up to 88 Hz are successfully identified (with mode assurance criterion (MAC) values exceeding 0.85) on a milling machine using the proposed system.