A relaxed structural mechanics and fuzzy control for fluid-structure dynamic analysis

Purpose This paper aims to deal with the problem of the global stabilization for a class of tension leg platform (TLP) nonlinear control systems. Design/methodology/approach It is well-known that, in general, the global asymptotic stability of the TLP subsystems does not imply the global asymptotic stability of the composite closed-loop system. Findings An effective approach is proposed to control chaos via the combination of fuzzy controllers, fuzzy observers and dithers. Research limitations/implications - If a fuzzy controller and a fuzzy observer cannot stabilize the chaotic system, a dither, as an auxiliary of the controller and the observer, is simultaneously introduced to asymptotically stabilize the chaotic system. Originality/value Thus, the behavior of the closed-loop dithered chaotic system can be rigorously predicted by establishing that of the closed-loop fuzzy relaxed system.