Aiming at the shortcomings of hydropower unit vibration signal denoising using ensemble empirical mode decomposition (EEMD), a denoising algorithm based on an improved fruit fly optimization algorithm (RFOA) for optimizing the EEMD noise IMF component threshold was proposed. Firstly, the noise signal was decomposed using the EEMD algorithm to obtain the IMF components, and then the correlation coefficient method was used to determine the noise signal and the effective signal. Then, the RFOA was used to determine the noise signal IMF component threshold. Finally, the sample entropy of the obtained IMF components was used as a feature vector input of the GRNN algorithm for vibration mode recognition. Compared with the wavelet threshold method and the EEMD-GA method, the results show that the proposed algorithm has the highest signal-to-noise ratio and the best denoising effect.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |