Neuro-Fuzzy Modeling and Fuzzy Control of a Fast Ferry - Fuzzy Modeling and Control: Theory and Applications - page 191

Fig. 10.8 Small replica of the ship

Fig. 10.9 T-foil ( left ) and flaps ( right )

Table 10.2 WVA (Worst Vertical Acceleration) andMSI (sea sickness index), experimental results,
without and with Fuzzy-PID Sugeno controller
SSN U (knots) WVA (without control) WVA MSI (without control) MSI

4 40 0.6069 0.2079 4.0844 0.1843

5 30 0.9031 0.6673 27.5710 17.7692

5 40 0.9900 0.5832 27.5444 12.0813

According to the results shown in Table 10.2 , the reduction of the vertical accel-
eration using this controller at SSN 4 and 40 knots is 65.74%. That means that the
MSI goes down from 4.08 to 0.18 (improvement of 95.49%). This result would allow
the ship to sailing even with waves 1.25-2.50m high, keeping a quite fast speed, 40
knots. Again, for SSN 5 (2.5-4m waves) the pitch acceleration is reduced using the
fuzzy control. At a speed of 30 knots, the WVA decrement is 26.11% and at 40 knots