Abstract: In the traditional vibration measurement, the laser monitoring device measures the single parameter of the motor only. To measure the mechanical vibration of the motor whose shaft center height is 56 mm and above, the dual channel independent measurement system is established, which can be used to measure the speed and vibration of the motor shaft at the same time. The vibration signal and velocity signal are obtained based on the principle of Fabry-Perot interference and speckle interferometry. After the synthetic signal is decomposed, the vibration signal is demodulated by Hilbert transform and the velocity signal is processed by autocorrelation function. The experimental results show that the accuracy of vibration measurement is less than 255 nm, and the relative error of velocity measurement is less than 0. 11% . The advantages of this experiment are non-contact, anti-electromagnetic interference and high precision. It is simple in structure and easy to operate and implement.

Key words: fabry-perot intervention, vibration measurement, rotational speed measurement, motor testing