Multi-degree-of-freedom non-Gaussian random vibration control

The drive signal and the response signal generated by traditional multi-degree-of-freedom (MDOF) random vibration control method are both Gaussian signal. However, the real vibration interference signal is always super-Gaussian, while sub-Gaussian random excitation is mainly used to reduce the maximum amplitude of the drive signal. To achieve MDOF sub-Gaussian and super-Gaussian vibration control, an MDOF non-Gaussian random vibration control method is proposed, which solve the coupling problem through system identification, and select special phase to generate non-Gaussian pseudo-random drive signal, and then the pseudo-random drive signal is transformed to real random non-Gaussian drive signal through time domain randomization. The sub-Gaussian and super-Gaussian experiments based on a Hexapod-based MDOF micro vibration test bed show that the response power spectral density (PSD) of response signals obtained by the proposed method are limited to ±3 dB error band of reference PSD. Compared to that in the Gaussian experiment, the drive signal in the sub-Gaussian experiment decreases by more than 20%. In the super-Gaussian experiment, the error between the kurtosis of response signal and the reference value is within 0.2. Effectiveness of the proposed method can be validated by the experiment results. © 2017, Press of Chinese Journal of Aeronautics. All right reserved.