Variable structure control based on artificial immune network optimization approach for lift fin stabilizer

As a result of removing nonlinearity and uncertainty in the transform from fin angle to lift force, fin stabilizer with lift feedback can get better effect compare with that of angle feedback. But the effectiveness of lift feedback fin stabilizer can severely be deteriorated due to nonlinear and uncertainty effects arising from the parameter perturbations and external disturbances in the roll motion equation. A variable controller was introduced in this paper for its attractive features in deal with those parameters perturbation and disturbances. The performance of these variable structure controllers depends not only on its structure but also on the values of the controller's parameters. In this paper, an artificial immune system was used to tune the controller's parameters automatically to enhance performance of suppressing roll and reduce system chattering.