|Direct Adaptive Fuzzy Control with Less Restrictions on the Control Gain
Phi Anh Phan and Timothy J. Gale
International Journal of Control, Automation, and Systems, vol. 5, no. 6, pp.621-629, 2007
Abstract : In the adaptive fuzzy control field for affine nonlinear systems, there are two basic configurations: direct and indirect. It is well known that the direct configuration needs more restrictions on the control gain than the indirect configuration. In general, these restrictions are difficult to check in practice where mathematical models of plant are not available. In this paper, using a simple extension of the universal approximation theorem, we show that the only required constraint on the control gain is that its sign is known. The Lyapunov synthesis approach is used to guarantee the stability and convergence of the closed loop system. Finally, examples of an inverted pendulum and a magnet levitation system demonstrate the theoretical results.
Keyword : Affine nonlinear system, direct adaptive fuzzy control, less restriction on the control gain, neural fuzzy system.