Application of L1 Adaptive Controller to Longitudinal Dynamics of a High Manoeuvrability Aircraft

An L1 adaptive controller is proposed to control the short period dynamics of the F-18 HARV experimental aircraft when affected by bounded uncertainties, bounded external disturbance and time delay. The reference model is improved with a linear quadratic regulator (LQR) applied to the short period nominal dynamics model. The L1 adaptive technique is used to attenuate the effects of the uncertainties, disturbance and time delay and to track the response of the augmented reference model. Simulation results verify that the proposed L1 adaptive controller ensures smooth transient behaviour for the control and output signals simultaneously, in addition to asymptotic tracking.