Limited authority adaptive control architectures with dynamic inversion or explicit model following

Aerospace adaptive control has exploited a variety of control techniques since its initial debut in the pursuit of robustness and fault tolerance. This variety of both taxonomy and approaches can create a system of systems which may make generalizations difficult. This paper contributes to the understanding of adaptive systems by synthesizing connected literature to explore the interactions of a baseline adaptive control architecture and trace its development. Comparable performance is shown with explicit model following (EMF) and dynamic inversion (DI) in series feedback with adaptive and linear controller. Articles were included in the review which led to the development of an architecture with dynamic inverse, control allocation, saturation, explicit model following, and adaptive element or demonstrated their interaction effects. A Lyapunov based stability proof was conducted to show stability of the EMF architecture with limited authority pseudocontrol hedge. Robust and limited authority cases were demonstrated by simulation. DI in series and EMF adaptive control architectures were found to have comparable performance under both conditions. Both techniques serve a similar purpose. While dynamic inversion has a clearer implementation and stability proof, many existing rotorcraft use explicit model following for its advantages; integrating EMF with adaptive control produces a viable alternative.