| Predicting
waves and gusts
Mr. Erik Hermans works at the Applied Physics Institute
of the Delft University of Technology, as a member of the Signals, Systems
and Control Group. His specialization is time series analysis: a way to
model stationary stochastic signals, like, for example, waves.
Mr. Hermans says: “Our group at the University
has researched and implemented an algorithm to determine an accurate parametric
model for the signal dynamics using several statistical criteria”.
A detailed academic description of the so-called ARMASA toolbox in question
can be found here.
Currently, Erik and his group are working with RoboSail
systems on extending this algorithm to vector (multivariate) time series.
This can be used to determine cross correlation functions between different
signals. For example, we can use this technology to find the relation
between waves and wind-information, and thus obtain a far better measurement
“When you can compute these correlation functions
the dependence between for example the signal from the weather vane and
the other boat’s entities is known. In this manner it is easier
to determine the true wind direction. Also the true magnitude and direction
of the tide and waves can be more accurately measured”, Mr. Hermans
comments.
The next step (this has been already partially implemented
in the recent software) is that on base of the vector time series analysis
we can make better predictions of direction and magnitude of future waves,
tides and wind.
To see if theory and software also work in practice,
the Signals, Systems and Control Group also has a connection with the
Dutch centre of weather-expertise, KNMI. The KNMI has measured, amongst
other things, wind speed and -direction and wave speed/direction on an
oil rig in the North Sea. A lot of research is also conducted onboard
RoboSail’s sailing laboratory, the Open40 Syllogic.
At the end we aim at implement the vector time series
analysis in the experimental X-Pilot autopilot onboard Syllogic. In the
somewhat longer term, this research will find its way to the RoboSail
Odys™ Intelligent Pilot.
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