Digital Transformation of Industrial Automation

Project Overview

This project addresses one of the most significant challenges in industrial automation: migrating legacy control systems from IEC 61131-3 to the modern, distributed IEC 61499 standard. By leveraging Large Language Models (LLMs), we aim to automate and accelerate the transformation of PLC codebases, function block libraries, and system specifications.

The Challenge

IEC 61131-3 has been the dominant standard for Programmable Logic Controller (PLC) programming since 1993. However, the industry is increasingly moving toward IEC 61499, which offers:

• Distributed execution: Native support for distributed control systems
• Event-driven architecture: More responsive and efficient control logic
• Platform independence: True portability across vendor hardware
• Enhanced modularity: Better encapsulation through composite function blocks

The migration challenge is substantial—decades of proven IEC 61131-3 code, including Structured Text (ST), Ladder Diagram (LD), Function Block Diagram (FBD), and Sequential Function Charts (SFC), must be carefully converted while preserving functional correctness and safety guarantees.

Our Approach

LLM-Powered Code Transformation

We are developing an AI-assisted pipeline that uses fine-tuned LLMs to:

1. Parse and understand legacy IEC 61131-3 programs across all five programming languages
2. Extract semantic intent from control logic, including timing constraints, safety interlocks, and process dependencies
3. Generate equivalent IEC 61499 function blocks with proper event interfaces and execution semantics
4. Validate transformations through formal verification and simulation

Library Migration

Beyond individual programs, we are creating tools to migrate entire function block libraries:

• Automatic conversion of reusable FB libraries to IEC 61499 format
• Preservation of interface contracts and documentation
• Generation of composite function blocks for complex subsystems
• Mapping of vendor-specific extensions to standard constructs

Specification Rewriting

LLMs assist in transforming technical specifications and documentation:

• Converting IEC 61131-3 application specifications to IEC 61499 system models
• Generating updated documentation reflecting the new architecture
• Creating migration guides and traceability matrices

Technical Implementation

The system architecture combines multiple AI and automation technologies:

• Code Analysis Engine: Static analysis tools for IEC 61131-3 parsing and AST generation
• LLM Core: Fine-tuned models trained on industrial automation codebases and standards
• Transformation Rules: Hybrid approach combining learned patterns with formal transformation rules
• Verification Suite: Automated testing and formal methods for correctness validation
• IDE Integration: Plugins for popular automation development environments

Expected Outcomes

• 90%+ automation of routine code conversion tasks
• Significant reduction in manual migration effort and associated costs
• Improved code quality through consistent application of best practices
• Accelerated adoption of IEC 61499 in industrial settings

Research Contributions

This project advances the state of the art in:

• Application of LLMs to domain-specific programming languages
• Formal verification of AI-generated industrial control code
• Hybrid AI-symbolic approaches to code transformation