EAAI Journal 2025 Journal Article
Data-driven models with physical interpretability for real-time cavity profile prediction in electrochemical machining processes
- Ming Wu
- Zequan Yao
- Mathias Verbeke
- Peter Karsmakers
- Benjamin Gorissen
- Dominiek Reynaerts
The Electrochemical Machining (ECM) process can be effectively controlled by adjusting the process parameters, including electrolyte composition, current density, etc. However, this control strategy presents challenges associated with modeling the complex relationships between processing parameters and the resulting process outcomes. Data-driven approaches hold promise for real-time cavity profile prediction, while their black-box nature limits the interpretability. To address these issues, this study initiated by developing several Machine Learning (ML) models to predict cavity profiles using process parameters, in-process data, or a combination of both. Subsequently, these models were inspected by explainable artificial intelligence (XAI) methods. Using process parameters for model inspection provides preliminary guidance for achieving desired outcomes, while inspections with in-process data shed light on process dynamics and enable diagnostics by detecting anomalies through atypical model focus. Linear regression (LR), with high interpretability, offers moderate predictive accuracy, whereas neural networks (NN) and convolutional neural networks (CNN) perform better yet require XAI methods to interpret their decision-making mechanisms. Model inspection was conducted on global and local levels. Global inspection via SHapley Additive exPlanations (SHAP) for LR and NN models identified factors affecting cavity size, aligning predictions with ECM knowledge. Local inspection through Gradient-weighted Class Activation Mapping (Grad-CAM) examined CNN predictions, revealing temporal process dynamics and model focus during specific processing stages. The impact of unexpected events identified by the ML models was validated using a physics-based model. A web application was developed to integrate these insights, allowing for real-time cavity prediction and visualization based on process parameters and in-process data.