The high-order spectrum can effectively remove Gaussian noise. The three-spectrum and its slices represent random signals from a higher probability structure. It can not only qualitatively describe the linearity and n...The high-order spectrum can effectively remove Gaussian noise. The three-spectrum and its slices represent random signals from a higher probability structure. It can not only qualitatively describe the linearity and nonlinearity of vibration signals closely related to mechanical failures, Gaussian and non-Gaussian Performance, and can greatly i</span><span style="font-family:Verdana;"></span><span style="font-family:"">mprove the accuracy of mechanical fault diagnosis. The two-dimensional slices of trispectrum in normal and fault states show different peak characteristics. 2-D wavelet multi-level decomposition can effectively compress 2-D array information. Least squares support vector machine can obtain the global optimum under limited samples, thus avoiding the local optimum problem, and has the advantage of reducing computational complexity. In this paper, 2-D wavelet multi-level decomposition is used to extract features of trispectrum 2-D slices, and input LSSVM to diagnose the fault of the pressure reducing valve, which has achieved good results.展开更多
A combined magnetorheological damper combined with rubber spring and magnetorheological damper is addressed.This type of damping device has inherited the merits of rubber spring and the magnetorheological damper.The t...A combined magnetorheological damper combined with rubber spring and magnetorheological damper is addressed.This type of damping device has inherited the merits of rubber spring and the magnetorheological damper.The test damping device is made up of combined magnetorheological damper,amplitude controller,signal collecting device,computer software for dynamic analysis,etc.When a zeromean and non-Gaussian white noise interfere with the device,a time series autoregressive(AR) model is conducted by using the sampled experimental data.Trispectrum and its slices analysis are emerging as a new powerful technique in signal processing,which is put forward for investigating the dynamic characteristics of the magnetorheological vibrant device.The present of trispectrum and its slices analysis change with the variation of controllable working magnetic field of the damper correspondingly.It is indicated that AR trispectrum and its slices analysis methods are feasible and effective for investigation of magnetorheological vibrant device.展开更多
Higher order spectral analysis can be used to identify nonlinearities in the complex dynamical systems.This proposal shows that the contributions of the bispectrum,trispectrum,reconstructed bispectrum and reconstructe...Higher order spectral analysis can be used to identify nonlinearities in the complex dynamical systems.This proposal shows that the contributions of the bispectrum,trispectrum,reconstructed bispectrum and reconstructed power spectrum in terms of the system frequency response function and elementary physical properties of the MR damping system.Subsequent estimates of the HOS based on the output stochastic oscillating signals appear distinct variation.An experimental platform for MR vibrating semi-active control is built,proper simplifications are presented,an AR(10) model is established with colored noises from the output signals.Comparison between power spectrum from second order moment function and bispectrum,trispectrum are taken.The later gives an indication of the correlation between the phases of different frequency components.Since time series model is a parametric model,the reconstructed bispectrum and power spectrum are smooth.It is demonstrated that the higher order spectra are effectively for recognition and description of nonlinear systems.展开更多
In this paper, an algorithm for eliminating extreme values and reducing the estimation variance of an integrated trispectrum under low signal-to-noise ratio and short data sample conditions is presented. An analysis o...In this paper, an algorithm for eliminating extreme values and reducing the estimation variance of an integrated trispectrum under low signal-to-noise ratio and short data sample conditions is presented. An analysis of the results of simulations using this algorithm and comparison with the conventional power spectrum and integrated trispectrum methods are presented.展开更多
文摘The high-order spectrum can effectively remove Gaussian noise. The three-spectrum and its slices represent random signals from a higher probability structure. It can not only qualitatively describe the linearity and nonlinearity of vibration signals closely related to mechanical failures, Gaussian and non-Gaussian Performance, and can greatly i</span><span style="font-family:Verdana;"></span><span style="font-family:"">mprove the accuracy of mechanical fault diagnosis. The two-dimensional slices of trispectrum in normal and fault states show different peak characteristics. 2-D wavelet multi-level decomposition can effectively compress 2-D array information. Least squares support vector machine can obtain the global optimum under limited samples, thus avoiding the local optimum problem, and has the advantage of reducing computational complexity. In this paper, 2-D wavelet multi-level decomposition is used to extract features of trispectrum 2-D slices, and input LSSVM to diagnose the fault of the pressure reducing valve, which has achieved good results.
基金Project(2005H035) supported by Fujian Province of China
文摘A combined magnetorheological damper combined with rubber spring and magnetorheological damper is addressed.This type of damping device has inherited the merits of rubber spring and the magnetorheological damper.The test damping device is made up of combined magnetorheological damper,amplitude controller,signal collecting device,computer software for dynamic analysis,etc.When a zeromean and non-Gaussian white noise interfere with the device,a time series autoregressive(AR) model is conducted by using the sampled experimental data.Trispectrum and its slices analysis are emerging as a new powerful technique in signal processing,which is put forward for investigating the dynamic characteristics of the magnetorheological vibrant device.The present of trispectrum and its slices analysis change with the variation of controllable working magnetic field of the damper correspondingly.It is indicated that AR trispectrum and its slices analysis methods are feasible and effective for investigation of magnetorheological vibrant device.
基金Project(A0610020) supported by the Natural Science of Fujian Province of China
文摘Higher order spectral analysis can be used to identify nonlinearities in the complex dynamical systems.This proposal shows that the contributions of the bispectrum,trispectrum,reconstructed bispectrum and reconstructed power spectrum in terms of the system frequency response function and elementary physical properties of the MR damping system.Subsequent estimates of the HOS based on the output stochastic oscillating signals appear distinct variation.An experimental platform for MR vibrating semi-active control is built,proper simplifications are presented,an AR(10) model is established with colored noises from the output signals.Comparison between power spectrum from second order moment function and bispectrum,trispectrum are taken.The later gives an indication of the correlation between the phases of different frequency components.Since time series model is a parametric model,the reconstructed bispectrum and power spectrum are smooth.It is demonstrated that the higher order spectra are effectively for recognition and description of nonlinear systems.
基金Supported by the National Natural Science Foundation of China under Grant No.60072027
文摘In this paper, an algorithm for eliminating extreme values and reducing the estimation variance of an integrated trispectrum under low signal-to-noise ratio and short data sample conditions is presented. An analysis of the results of simulations using this algorithm and comparison with the conventional power spectrum and integrated trispectrum methods are presented.
