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Master's thesis: TrollFish

NTNU TrollLABS, for the Norwegian Sailing Federation and Olympic Training Centre · 2025–2026

TrollFish lets a coach and athlete go back through a sailing session afterwards. Video, GPS and sensor data sit on the same timeline, so you can jump to a particular tack and see what happened.

Everything had to work with equipment a national team can afford. ILCA rules also allow only one camera on board, so that single camera has to do the whole job.

Two peer-reviewed papers came out of the work, one on 3D pose estimation from 360° video and one on sensor fusion between IMUs and load cells.

An ILCA dinghy sailing at speed on open water, with mountains behind.
An ILCA. This is the class the system was built for.

The equipment on board

The equipment stays in the boat for the whole session and has to handle sea and salt. It is a hiking strap with sensors inside, pressure mats on the deck, and a box that logs it all.

The cockpit seen from above, with the instrumented hiking strap along the centre, a clear electronics box, and pressure mats taped to the deck.
The strap, the electronics box and the pressure mats as fitted in the boat.
Side-view diagram of the hiking strap, with seven IMUs spread along the curve the strap hangs in, and the point HCoM marked at the top.
The sensors along the strap measure the curve it hangs in. From that curve comes the point where the athlete's weight acts.
Four pressure mats shown as heatmaps, labelled MAT 1 to MAT 4, each a grid of readings in green and yellow.
The pressure mats show how weight is spread where the athlete sits.

The tool

Screenshot: a GPS track on a map on the left, three synchronised video panes on the right, and a timeline along the bottom showing speed, heading and heel.
Video, GPS track and statistics on one timeline.
Screenshot: two athletes compared with centre-of-mass heatmaps, summary figures and graphs for wind angle, heading and heel.
Two athletes compared over the same stretch.
Camera frame of a sail with detected contour lines for the luff, leech and three horizontal stripes.
Sail shape read out of the frame from the camera on board.
Generated PDF report with a map of the session, a summary table, histograms, heatmaps and polar plots.
The report that comes out after a session.

Publications

Further development

TrollFish is built as a framework, not as a finished product for one boat class. The synchronisation, manoeuvre detection, computer vision and reports can be adapted to other classes, other sports, or entirely different uses.

I am happy to take on work building on it, whether for sailing or as a starting point for something else. Get in touch.

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