自适应多尺度噪声调节二阶随机共振增强方法

The best matching between noise, periodic signal, and a nonlinear bistable system can be realized through tuning various parameters to achieve stochastic resonance in the classical bistable stochastic resonance system. It makes that a weak periodic component in the system output gets a certain amount of noise energy and achieves enhanced effect. Thus the weak periodic components can be effectively detected. However, the capability of using noise to enhance signal is limited. There is still some useful noise in the system response. Hence, aiming at the repeated utilization of the noise by virtue of double integration, a system model using a second-order stochastic resonance enhanced method was proposed to reuse the noise twice and effectively promote high-frequency noise energy transferring to the low-frequency area in order to improve the signal-to-noise ratio of output response effectively. The second order stochastic resonance enhancement method based on the adaptive multiscale noise tuning of using Paul wavelet, with the collaborative signal to noise ratio (CSNR) as the objective function, was proposed in the work, taking the effect of the multiscale noise on stochastics resonance into account, and based on the mathematical nature of the special low-pass filter of stochastic resonance. This method makes full use of the ability of multi-resolution time-frequency analysis of wavelet, which can divide the input signals and noise into different frequency bands for realizing the control of intensity of signal and noise in different frequency bands. The property of the second order stochastic resonance, which can achieve the enhancement utilization of the noise energy in the signals, has been fully used. The proposed method has been validated by simulation tests and actual application in engineering.