Nonlinear flight test trajectory controllers for aircraft

TLDR

Flight‑test trajectory control systems enable pilots to follow complex trajectories within an aircraft’s known envelope and probe its limits, whereas earlier linearized‑model designs required extensive data storage and gain schedules. This paper presents the synthesis of nonlinear flight‑test trajectory controllers for a fixed‑wing aircraft. The synthesis uses singular perturbation theory and prelinearizing transformations to produce a direct, noniterative analytic solution. The resulting controllers operate satisfactorily without gain scheduling, support arbitrarily nonlinear maneuvers, and are mechanized with a direct, noniterative analytic solution.

Abstract

Flight test trajectory control systems are designed to enable the pilot to follow complex trajectories for evaluating an aircraft within its known flight envelope and to explore the boundaries of its capabilities. Previous design approaches were baed on linearized aircraft models necessitating a large amount of data storage along with gain schedules. In this paper, the synthesis of nonlinear flight test trajectory controllers for a fixed-wing aircraft is described. This approach uses singular perturbation theory and the recently developed theory of prelinearizing transformations. These controllers do not require gain scheduling for satisfactory operation, can be used in arbitrarily nonlinear maneuvers, and are mechanized with a direct, noniterative analytic solution.