Fuzzy control to multivariable systems case study: helicopter model

This paper presents a general hierarchical fuzzy control design for multivariable systems. The control structure consists of two levels. The first one generates the basic control signals when the system is decoupled. The second one behaves as a fuzzy decoupler to anticipate and to compensate the coupling effect on the system outputs. This level is achieved using simple and reduced number of fuzzy rules. These rules can be driven from the open loop system's response. Therefore, the second level generates the control signals applied to the physical system. A simulation study is performed on a real multivariable helicopter model to manipulate the elevation and azimuth angles with significant cross coupling between these controlled variables. The results obtained showed the potential of the proposed design approach and its effectiveness to control multivariable systems.