Control strategy for multi-axial swept sine on random mixed vibration testing

Abstract

The control method for the multi-axial swept sine on random vibration test is studied in this paper. For the swept sine on random vibration test, the signals at the control points are the superposition of swept sine signals and random signals. Therefore, the main problem of the kind of test is the separation of the signals. Firstly, the swept sine integration method is studied for the separation of the swept sine components and the random components from the mixed signals. Then, the extracted accuracy is compared with different parameters. Thirdly, two methods are proposed to obtain the power spectral densities of the random components. Finally, according to the deviations between each component and the specified references, the driving signals of shakers are iteratively updated to ensure that the responses at the control points are controlled within the specified requirements. Numerical simulation and experimental results show that the proposed method is feasible for the multi-axial swept sine on broadband random vibration control test.