A new hybrid direct/indirect adaptive fuzzy neural network (FNN) tracking control equipped with VSS and H ∞ control algorithms for a class of uncertain nonlinear dynamic systems involving external disturbance is developed in this paper. The hybrid adaptive FNN controller constructed by adaptive fuzzy control law, VSS controller and robust H ∞ controller is a combination of direct and indirect adaptive FNN controllers. A weighting factor, which is adjusted by the trade-off between plant knowledge and control knowledge, is appended between indirect adaptive FNN control and direct adaptive FNN control. By incorporating robust VSS and H ∞ control techniques, FNN tracking control can be extended towards a large class of uncertain nonlinear systems. The overall adaptive scheme guarantees the global stability of the resulting closed-loop system in the sense that all signals involved are uniformly bounded. The resulting FNN control system shows better performance, i.e., an arbitrary small attenuation level can be achieved; and it is more flexible during the design process. To illustrate the design methodology, it is applied to a spring-mass-damper system.
|Number of pages||12|
|Journal||International Journal of Electrical Engineering|
|State||Published - 1 Feb 2004|
- Direct adaptive control
- Indirect adaptive control
- Robust H control