A control method for Multi-Input Multi-Output（MIMO） non-Gaussian random vibration test with cross spectra consideration is proposed in the paper. The aim of the proposed control method is to replicate the specified ...A control method for Multi-Input Multi-Output（MIMO） non-Gaussian random vibration test with cross spectra consideration is proposed in the paper. The aim of the proposed control method is to replicate the specified references composed of auto spectral densities, cross spectral densities and kurtoses on the test article in the laboratory. It is found that the cross spectral densities will bring intractable coupling problems and induce difficulty for the control of the multioutput kurtoses. Hence, a sequential phase modification method is put forward to solve the coupling problems in multi-input multi-output non-Gaussian random vibration test. To achieve the specified responses, an improved zero memory nonlinear transformation is utilized first to modify the Fourier phases of the signals with sequential phase modification method to obtain one frame reference response signals which satisfy the reference spectra and reference kurtoses. Then, an inverse system method is used in frequency domain to obtain the continuous stationary drive signals. At the same time, the matrix power control algorithm is utilized to control the spectra and kurtoses of the response signals further. At the end of the paper, a simulation example with a cantilever beam and a vibration shaker test are implemented and the results support the proposed method very well.展开更多
This paper presents a review of the various methods for the stationary non-Gaussian random vibration control.Random vibration tests can be divided,according to the number of exciters,in single-shaker tests and multipl...This paper presents a review of the various methods for the stationary non-Gaussian random vibration control.Random vibration tests can be divided,according to the number of exciters,in single-shaker tests and multiple-shaker tests.In the stationary non-Gaussian random vibration test,the time and frequency domain characteristics of the responses should be controlled independently and simultaneously.Skewness and kurtosis are usually selected as the nonGaussian time control references(targets)while power spectral density is the frequency domain control procedure before it recalls the concepts of non-Gaussianity.Then,the generation of a one frame stationary non-Gaussian random signal for both the single and multiple shakers are reviewed.The commonly used methods for the single non-Gaussian random signal generation in the random vibration test are memoryless nonlinear transformation,phase modification and Filtered Poisson process.For the multiple-shaker case,the sequential phase modification and memoryless nonlinear transformation are used to generate one frame coupled multi-channel non-Gaussian random signal.In order to obtain a stationary and consecutive dynamic input,the time domain randomization procedure is introduced with high computational efficiency and its influences on the skewness and kurtosis are analyzed.Finally,two existing problems in the non-Gaussian random vibration control are addressed.展开更多
基金supported by the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe Postgraduate Research & Practice Innovation Program of Jiangsu Province (No. KYCX17_0234)
文摘A control method for Multi-Input Multi-Output（MIMO） non-Gaussian random vibration test with cross spectra consideration is proposed in the paper. The aim of the proposed control method is to replicate the specified references composed of auto spectral densities, cross spectral densities and kurtoses on the test article in the laboratory. It is found that the cross spectral densities will bring intractable coupling problems and induce difficulty for the control of the multioutput kurtoses. Hence, a sequential phase modification method is put forward to solve the coupling problems in multi-input multi-output non-Gaussian random vibration test. To achieve the specified responses, an improved zero memory nonlinear transformation is utilized first to modify the Fourier phases of the signals with sequential phase modification method to obtain one frame reference response signals which satisfy the reference spectra and reference kurtoses. Then, an inverse system method is used in frequency domain to obtain the continuous stationary drive signals. At the same time, the matrix power control algorithm is utilized to control the spectra and kurtoses of the response signals further. At the end of the paper, a simulation example with a cantilever beam and a vibration shaker test are implemented and the results support the proposed method very well.
基金co-supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions,china。
文摘This paper presents a review of the various methods for the stationary non-Gaussian random vibration control.Random vibration tests can be divided,according to the number of exciters,in single-shaker tests and multiple-shaker tests.In the stationary non-Gaussian random vibration test,the time and frequency domain characteristics of the responses should be controlled independently and simultaneously.Skewness and kurtosis are usually selected as the nonGaussian time control references(targets)while power spectral density is the frequency domain control procedure before it recalls the concepts of non-Gaussianity.Then,the generation of a one frame stationary non-Gaussian random signal for both the single and multiple shakers are reviewed.The commonly used methods for the single non-Gaussian random signal generation in the random vibration test are memoryless nonlinear transformation,phase modification and Filtered Poisson process.For the multiple-shaker case,the sequential phase modification and memoryless nonlinear transformation are used to generate one frame coupled multi-channel non-Gaussian random signal.In order to obtain a stationary and consecutive dynamic input,the time domain randomization procedure is introduced with high computational efficiency and its influences on the skewness and kurtosis are analyzed.Finally,two existing problems in the non-Gaussian random vibration control are addressed.
