Fuzzy control method for a special motion system

By analyzing the limited conditions of a special motion system, a synthetic controller composed of prediction, compensation, and fuzzy logic is developed. To overcome the problem of underwater too deep caused by the delay between the time of special motion system into water and the time of engine fired, a prediction elevator deflect is adopted. Since some initial values may appear, heavy oscillation responses phase-lead compensation is used to increase stability margins of the system. Above control methods can make the special motion system into given underwater depth. Thus, fuzzy logic is selected as controller for all of the special motion system. By using maximum likelihood method and error sequences between desired outputs and system outputs, parameters in fuzzy logic controller are obtained. Simulations and actual tests show that the new method can give satisfactory results in engineering.