In order to implement an accurate system that allows for absorption of reflected
waves impinging to a wave maker (Active Reflection Absorption), it was required to
apply a method to estimate properly the direction of arrival of the waves that does it in
the fastest way possible. Our wavemaker control system has been prepared to handle an
algorithm provided by Bosch-Rexroth where the wave angle estimation is practically
locked to a very narrow frequency band (spatial gain-mixer). The system was evaluated
with physical tests in a 3D wave basin for different conditions of reflected waves
arriving with an angle to the wavemaker front, and acceptable performance has been
found for the 3D ARA mode. However, for certain conditions over-compensation or
sub-compensation can develop resulting in a poor absorption. This is mainly related to
not being able to determine accurately the direction from which the reflected waves
travel towards the wavemaker.
The present work employed concepts found in the areas of antenna array signal
processing and signal propagation, which were applied to this problem. This approach coupled naturally with our wavemaker system since it was prepared with 48 gages that
can be employed in an array antenna fashion. A program was codified from an algorithm
found in literature to calculate the Direction of Arrival (DOA) of the reflected waves.
The focus for the testing of this program was with regular waves.
The tests were conducted to validate the program with different angles of
incidence and show that for regular waves the program was able to detect accurately the
DOA of these in as few as 5 snapshots, with a minimum of 7 gages used as the antenna
input. With data obtained directly from the control system of our wavemaker using
regular waves, the program was able to determine the DOA. The computational burden
of the algorithm is not significant in the case of regular waves. A modification of the
program is required to analyze the DOA of reflected irregular waves, which could
increase the computational burden. Actual implementation of this program to our control
system depends on cooperation with Bosch-Rexroth.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2009-08-2922 |
| Date | 2009 August 1900 |
| Creators | Cruz Castro, Oscar |
| Contributors | Edge, Billy L. |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | application/pdf |
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