Design of an electrohydraulic wave follower system.
Authors
Daley, Michael
Subjects
Advisors
Houlihan, T.M.
Date of Issue
1977
Date
June 1977
Publisher
Language
en_US
Abstract
An electrohydraulic wave follower capable of positioning a 25.0 LB
instrumentation package at a constant height above the instantaneous
sea surface was designed. A derrick to move the system from the deck
of the R/V Acania to the water and retrieve it was also designed. The
motivation behind the project was to provide an instrumentation platform
which would enable the gathering of environmental data within the first
three feet of the sea surface.
The system is a valve controlled piston arrangement. The instruments
are affixed to the piston. The frequency spectrum of interest for this
design was from 1.0 to 10.0 HZ. The required amplitude response was
derived from linear wave theory using a maximum wave steepness of one
seventh. Position feedback was used exclusively in the controls scheme.
System modeling showed that the wave follower provided more than sufficient
cylinder amplitude response for the design payload in the frequency
design range. The phase response became degraded at higher frequencies.
However, this could be corrected by incorporating a lead/lag
section in the controls portion of the system.
Type
Thesis
Description
Series/Report No
Department
Mechanical Engineering
Organization
Naval Postgraduate School
Identifiers
NPS Report Number
Sponsors
Funding
Format
Citation
Distribution Statement
Approved for public release; distribution is unlimited.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.