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At present, the trend of complex and intelligent rotating machinery and equipment is becoming more and more obvious, which generates a large amount of high-dimensional and nonlinear fault monitoring data that is difficult to handle. This makes the traditional dimensionality reduction algorithms based on point-to-point metrics or a small number of graph embedding structures lose their utility. To solve this problem, a multiple feature-spaces collaborative discriminative projection (MFSCDP) algorithm for rotor fault dataset dimensionality reduction is proposed. The algorithm first improves the projection metric from sample point to feature space into the median metric in order to achieve the effect of weakening the extrapolation error of the algorithm, and based on this, we propose a sample point-to-point guided nearest-neighbor feature space selection method to improve the construction efficiency of the feature space embedding graph. Then, by using Relief F to indirectly construct the reduced dimensional projection matrix with multiple feature spaces of collaboration. Finally, the proposed MFSCDP algorithm is used for the dimensionality reduction process of the rotor fault dataset. The algorithm's performance was verified using experimental information from rotor failure simulations of two different structural types. The result shows that the algorithm can reduce the difficulty of fault classification and improve the accuracy of identification.

Rolling bearings play a vital role in ensuring the safe operation of rotating machinery. However, in many application scenarios, the collected data has a low signal-to-noise ratio and the samples with faults are rare, which affects the generalization capability of the model, making it impossible to achieve accurate diagnosis. To solve this problem, the selection of time-frequency (TF) maps was considered in this paper through reinforcement learning. The time-frequency maps are built by four classical time-frequency characterization methods such as short-time Fourier transform (STFT) and synchro squeezing transform (SST). And the match-reinforcement learning time frequency selection (MRLTFS) fault diagnosis model is proposed to extract the fault-related features. Experiments show that the proposed MRLTFS method is superior to existing methods in robustness, generalization and feature selection capability.