LF Molten Steel Temperature Control With Interpretable ML

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Solution Overview

Problem

Current prediction models for molten steel temperature during ladle furnace refining lack decision-making transparency and interpretability, leading to unreliable temperature control and fluctuations, which affect the quality and efficiency of the steel production process.

Innovation Solution

An interpretable machine learning method is implemented, using SHAP values and key factor parameters to calculate a predicted temperature and adjust process parameters, ensuring accurate control of the molten steel temperature by constructing a prediction model with hyperparameter optimization and preprocessing data to improve model accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a hybrid model of metallurgical mechanism model and machine learning model is used, then prediction accuracy is improved, but model interpretability deteriorates due to black-box problems

Engineering Contradiction:
Improveprediction accuracyVSAvoidmodel interpretability
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent introduces SHAP (SHapley Additive exPlanations) as an intermediary layer between the hybrid prediction model and the operator. SHAP values decompose the complex model output into interpretable contributions from each input feature, allowing operators to understand which parameters (e.g., heating time, alloy composition) most influence temperature predictions without simplifying the underlying complex model architecture.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces traditional opaque mathematical modeling approaches with a data-driven machine learning model enhanced by game-theory-based SHAP explanations. This substitution allows the system to capture complex nonlinear relationships in metallurgical processes while providing interpretable results through SHAP's cooperative game theory framework, which attributes prediction outcomes to specific input features in a mathematically rigorous manner.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If traditional temperature control based on operator experience is used, then operational flexibility is maintained, but temperature control stability deteriorates due to large fluctuations

Engineering Contradiction:
Improveoperational flexibilityVSAvoidtemperature control stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent implements a closed-loop feedback control system where the hybrid prediction model continuously forecasts molten steel temperature based on real-time process parameters (heating time, power input, alloy composition). These predictions feed back to operators who adjust control parameters accordingly, creating a continuous cycle of prediction-adjustment-verification that stabilizes temperature control while maintaining operational flexibility.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent applies preliminary action by using the prediction model to forecast temperature outcomes before actual processing occurs. Operators receive advance predictions of temperature evolution based on planned parameter settings, allowing them to pre-adjust control parameters to achieve target temperatures more accurately and reduce fluctuations during the actual heating process.

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If metallurgical mechanism model is used, then physical and chemical processes are described, but model accuracy deteriorates due to assumptions and simplifications

Engineering Contradiction:
Improvemodel construction feasibilityVSAvoidmodel accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent merges two complementary approaches: (1) a metallurgical mechanism model that incorporates physical and chemical process knowledge (providing interpretability and feasibility), and (2) a machine learning model that captures complex nonlinear relationships from data (providing accuracy). The ensemble hybrid model combines predictions from both components, leveraging the strengths of each to achieve both accuracy and construction feasibility.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent creates a composite modeling approach analogous to composite materials, where the hybrid model integrates heterogeneous components (mechanism-based predictions and data-driven predictions) with different properties. Each component contributes unique strengths: the mechanism model provides physical consistency and interpretability, while the machine learning component provides adaptive accuracy. Their combination creates a superior integrated model that overcomes the limitations of individual approaches.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentUS12146200B1Method and device for controlling temperature of molten steel during ladle furnace (LF) refining based on interpretable machine learning
Publication Date: 2024.11.19 UNIV OF SCI & TECH BEIJING
  • US12146200B1 patent drawing
  • US12146200B1 patent drawing
  • US12146200B1 patent drawing

AI summary

A method for controlling a temperature of a molten steel during ladle furnace (LF) refining based on interpretable machine learning includes: acquiring process data of the LF refining and a target temperature of the molten steel during the LF refining; acquiring a prediction model for the temperature of the molten steel during the LF refining; calculating a base value for prediction of the temperature of the molten steel, SHapley Additive explanations (SHAP) values of key factor parameters, and a relationship trend between the key factor parameters and the SHAP values; and calculating a predicted value of the temperature of the molten steel during the LF refining, and acquiring a control result for the temperature of the molten steel during the LF refining according to the relationship trend and the predicted value of the temperature of the molten steel during the LF refining.