Affiliations: [a] School of Mechanical and Electronic Engineering, Wuhan University of Technology, Wuhan, Hubei, China | [b] Philips Research North America, Cambridge, MA, USA
Correspondence:
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Correspondence author: Chunsheng Song, School of Mechanical and Electronic Engineering, Wuhan University of Technology, Wuhan 430070, Hubei, China. Tel.: +86 13437161368; E-mail:songchsh@whut.edu.cn
Abstract: A floating raft system is a special double-layer
isolation system aiming to reduce the level of noise and vibration and has
been widely applied to many kinds of ships and submarines. It can isolate
vibration of hosts and auxiliary machines and reduce the structural noise of
ships and submarines effectively. It can also protect the equipments and
instruments in ships and submarines from being damaged, and makes them to be
operated properly when ships and submarines are subjected to external loads
and sudden shocks. However, the floating raft system is generally a flexible
structure and it is subject to multiple frequency disturbances. The design
of control systems to enhance its isolation performance is an active area of
research. This paper presents improvements achieved by using a dynamic step
FXLMS controller whose main benefit is to balance convergence speed and
steady-state error by making the convergence coefficient vary with time. The
mathematical model of the dynamic system to be used in the controller is
obtained by the observer/Kalman filter identification (OKID) method. The
performance of the new solution (dynamic step size FXLMS with OKID model) is
compared with previous work based on a fuzzy controller and a dynamic model
identified via the prediction error method. Both simulated and experimental
results confirm the validity and the benefits of the approach.
