L_1 Adaptive Control Design for Improved Handling of F/A-18 class of Aircraft

摘要

This paper presents the development and preliminary results obtained from the application of (L)_1 adaptive control methods to the design of the inner-loop flight control system of variants of the F/A-18 aircraft, intended to emulate the handling qualities of the standard reference F/A-18 aircraft. The control method is designed to be robust to high frequency and unmodeled dynamics always present when a complex nonlinear system is approximated as a linear plant for design purposes. Results show the capability of the (L)_1 adaptive controller to effectively manipulate the naturally lightly damped pitch and roll dynamics of the uncontrolled plant to the desired dynamics of the easier-to-control standard F/A-18 with bounded transient responses and steady state tracking errors over a range of operating conditions. The ability to synthesize controllers based on a set of desired reference dynamics allowing the onboard controller to synthesize suitable stabilising and error regulating control commands for the plant possesses many of the prerequisites needed to form the basis of a standard set of certifiable flight control software designs.