Enhancing circuit diagram understanding via near sight correction using VLMs

Introduction
When an engineer needs to diagnose a fault or validate a design, the difference between minutes and hours depends upon how quickly a legacy circuit schematic can be interpreted and trusted.
At Hitachi, digital transformation is a core, organization-wide effort to convert deep engineering knowledge and legacy assets into scalable, data-driven capabilities. Electrical schematics represent a particularly high-value knowledge asset within this transformation, as they underpin system design, verification, maintenance, and long-term asset management across our industrial businesses. Much of this information, however, remains locked in image-based and document-centric formats. Moving from static schematics to machine-interpretable representations is therefore essential for enabling automation, analytics, and intelligent decision support across the full lifecycle of complex systems.

