ISDE diffusion model with hierarchical cross modal generative decoder: a data augmentation method for fault diagnosis under imbalanced data
摘要
The imbalanced data problem seriously restricts the engineering application of Prognostics Health Management (PHM) technology. Aiming at the limitations of existing data augmentation models in modeling complex vibration signals, an Improved Stochastic Differential Equation (ISDE) diffusion model with a hierarchical cross modal generative decoder is proposed. Firstly, the SDE diffusion theory is introduced into the task of generating industrial vibration signals, and a global–local collaborative modeling strategy is designed by integrating the potential function and scoring network to construct the drift term of the diffusion model, precise control of distribution evolution is achieved; Secondly, an adaptive diffusion mechanism is proposed to improve the robustness of the model to complex industrial noise; Finally, a hierarchical cross modal decoder is constructed, which combines multi-layer decoding structure and cross modulation mechanism to achieve hierarchical reconstruction of multi-scale features. The experimental results show that the proposed ISDE diffusion model can effectively generate data, and significantly improve fault diagnosis accuracy on both publicly available single fault datasets and self-built composite fault datasets when imbalance ratio reach to 20:1. The research results provide reliable technical support for the health management of industrial equipment, which has important theoretical value and engineering significance.