Novel e-Modification Robust Adaptive Control Scheme Using Non-Quadratic Lyapunov Functions for Higher Order Systems

Adaptive control laws are modified to obtain robust adaptive control schemes in the presence of disturbance. One of the well known modifications in robust adaptive control is the e-modification scheme; this modification has always been developed based on Lyapunov stability theory using the standard form of quadratic Lyapunov function (QLF). In contrast to such development and as a continuation to the effort done by the authors in this area, this paper presents new robust adaptive laws for e-modification scheme using novel non-quadratic Lyapunov function (NQLF) for higher order systems. These new laws offer better performance represented in a fast response of the output error signal while going to zero with a less number of oscillations. Simulation results for a third order system are illustrated in the paper to verify the advantages of using these new laws for higher order systems