The University MULSER2014 funded Qualisys optical motion capture systems is now in operation in our new towing tank. It is also available for use at other locations including swimming pools as it consists of four underwater and eight above water cameras.
Dr Chris Phillips reports that at the end of March a small group of academics & researchers from both FSI and WUMTIA joined Phil from Qualysis to learn more. We were taken through the capabilities of the Qualysis system, illustrating applications in naval architecture as

well as biomechanics. We were then taken through the crucial above and below water calibration phase to get the targeted ±0.4mm accuracy, before doing some simple trials ourselves.
The possibilities this new capability of accurately tracking precise locations, above and or below water, has given us is extensive. With much of the system portable too, we’re not just limited to the towing tank, opening up other test sites and facilities such as in wind tunnels, swimming pool or motion capture platforms. There have been many research and commercial ideas already suggested, including; flexible rudders and hull forms in combination with DIC, sail performance, autopilot evaluations, UAV trials and performance sports analysis.
The first use of the system was for the SESS6067 Wave Energy lab were PhD student James Bowker developed two point absorbers and students tested their response in varying wave frequencies as well as their relative six degree of freedom motion. Once set up the system worked reliably throughout the two days of student testing with 50 students taking part in the laboratory.
Recently James has also used the system to capture the motion response of the wave powered autonomous surface vessel Fleur. The video shows Fleur making her way into the wave and then the motion captured of the markers on her deck.