Neuro-Fuzzy Modeling and Fuzzy Control of a Fast Ferry - Fuzzy Modeling and Control: Theory and Applications - page 189

Fig. 10.6 Pitch moment control, regular waves
Fig. 10.7 Pitch moment correction, irregular waves
system is improving. To summarize, the final results are two Sugeno-type optimized
fuzzy PID controllers, one for the flap and another for the T-foil. The generated sys-
tems have a small number of function-rules and can be applied on-line on the real
system.
10.4 Results on a Real System
10.4.1 Simulation Results
Simulation results have been obtained, for regular and irregular waves, when applying
the fuzzy controllers described in Sect. 10.3 . Figures 10.6 and 10.7 showhow the pitch
moment is reduced when the Mamdani fuzzy control is applied (López and Santos
2002 ).
Table 10.1 summarizes the values of the Motion Sickness Incidence (MSI)
obtained at different sea states (SSN 4-6) and different speeds (20-40 knots). As
it is possible to see, just adding the actuators has an effect on the vertical accelera-
tion of the ship. The fuzzy controller significantly reduces the pitch acceleration and
therefore the sea sickness index, which is defined as a function of the vertical motion
of the ship.