Abstract:

We proposed a novel adaptive fuzzy sliding control to deal with the control problem of a class of non\|affine non\|linear systems with unknown control direction, requiring no prior knowledge of the control direction and bound of uncertainty. Fuzzy logic system is used to directly approximate the unknown part of the controller. Nussbaum function is applied in parameter updating laws to deal with the problem of unknown control direction. A new nonlinear saturation function is introduced to promote the performance of the traditional integral sliding mode surface, therefore the proposed controller can maintain the tracking accuracy with better dynamic performance. The stability of the closed\|loop system is performed by Lyapunov approach. Simulation results are provided to verify the effectiveness of the proposed design.

Key words: non-affine non-linear, Nussbaum function, nonlinear integrator, sliding mode control, fuzzy control