A Multi-Branch Deep Feature Fusion Network with SAE for Rare Earth Extraction Process Simulation

The Rare Earth Extraction Process (REEP) model is difficult to accurately establish via the extraction mechanism method due to its high complexity. This paper proposes a multi-branch deep feature fusion network with SAE (SAE-MBDFFN) for modeling REEP. We first design a neural network with a multi-branch output structure to simulate the cascade REEP by introducing a multiscale feature fusion mechanism, which can simultaneously concatenate hidden features, original features, and inter-branch coupling features. In order to deal with insufficient labeled data during model training, we then adopt a stacked Sparse Auto-Encoder (SAE) technology to extract the hidden information of mass unlabeled data based on unsupervised learning. This technology can determine the initial parameters of SAE-MBDFFN by unsupervised pretraining. The design methodology of the network is well-founded. Experiments on industrial data indicate that the proposed method has the lowest initial loss value and a faster convergence rate in the fine-tuning stage than other comparison methods, while the prediction accuracy is better well. These results show the effectiveness of the proposed method.