Ontology-Grounded Large Language Models for Reliable Querying of Wind Turbine Inspection Knowledge

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Published Jul 3, 2026
Louis Verstraeten Xavier Chesterman Jan Helsen Ann Nowé

Abstract

Inspection reports of industrial assets contain valuable diagnostic knowledge, but their unstructured nature makes automated reasoning difficult. This paper presents an ontology-grounded question answering framework for querying wind turbine gearbox inspection reports using natural language. Inspection data are automatically parsed into structured representations consisting of a domain ontology and a knowledge graph. On top of this representation, a large language model translates user questions into SPARQL queries. To improve robustness, we employ example-based query generation combined with an Ontology-Based Query Checker (OBQC) that validates generated queries against ontology constraints and iteratively repairs violations before execution. The approach is evaluated on real-world inspection reports using 50 diagnostic prompts of varying complexity, achieving a 96\% successful execution rate. Results demonstrate that combining ontology grounding with constrained LLM-based query generation enables reliable and flexible diagnostic reasoning over inspection documentation.

How to Cite

Verstraeten, L., Chesterman, X., Helsen, J., & Nowé, A. (2026). Ontology-Grounded Large Language Models for Reliable Querying of Wind Turbine Inspection Knowledge. PHM Society European Conference, 9(1), 1–10. https://doi.org/10.36001/phme.2026.v9i1.4947
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Keywords

Large Language Models (LLMs), Knowledge Graphs, SPARQL Generation, Ontology, Predictive Maintenance, Wind Energy

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Technical Papers