Research Project
Underwater Positioning System
Project Duration
2025–2026
Role and Contribution
Project Manager and Lead Developer (Full contribution)
Technologies and Skills Applied
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Embedded Hardware Design (OrCAD: Schematic Design, PCB Layout)
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Embedded Software Development (STM32: C)
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Mechanical Design (CAD)
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Hardware Integration
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Scientific Writing (IEEE Journal)
Introduction
Underwater positioning remains a significant challenge, as GPS and infrared signals are attenuated by water, while acoustic methods suffer from severe signal reflections in confined environments such as spent fuel pools or fire protection reservoirs.
To address this, I developed an Active Fiducial Marker System that enables centimetre-level underwater positioning to facilitate the precise inspection of aquatic environments.
Active Fiducial Marker System
The Active Fiducial Marker System utilises an array of 475 nm blue LEDs—specifically chosen for their minimal water absorption—to dynamically generate marker patterns.
The system employs stroboscopic operation, illuminating the markers for only a few milliseconds at a time. This technique effectively eliminates interference from ambient lighting. Furthermore, the stroboscopic effect “freezes” motion, enabling reliable, blur-free localisation even for fast-moving robots.
Additionally, because the markers are actively illuminated, vision-based communication using ArUco patterns can be conducted simultaneously with the localisation process.
Underwater Robot for Nuclear Power Plant
As the student project leader, I directed the development of an underwater robot system designed for the precise inspection of enclosed aquatic environments, such as fire protection reservoirs and spent fuel pools.
I designed the robot’s mechanical structure in SolidWorks and utilised my robot interface board as the main controller. Multiple underwater tests have verified that the robot operates flawlessly at depths of up to 10 metres, performing high-precision inspections using a camera and a line laser module.
Overview of Active Fiducial Marker System
Relative Positioning Between Robots Using the Proposed System (Sep 2025)
Precise Underwater Positioning of Robot Using Active Fiducial Marker System (Sep 2025)
Comparison of the Proposed Active (Left) and Passive (Right) Markers under Various Lighting Conditions (Sep 2025)
Underwater Enclosure and PCB for the System (Sep 2025)