Nonlinear adaptive flight control with a backstepping design approach

摘要

This paper examines the use of adaptive backstepping for multiaxis control of a high performance aircraft. ^The control law is demonstrated on a six-degree-of-freedom simulation with nonlinear aerodynamic and engine models, actuator models with saturation, and turbulence. ^Simulation results are demonstrated for large pitch-roll maneuvers and for maneuvers with failure of the right stabilator. ^There are substantial differences between the control law design and simulation models, which are used to demonstrate some robustness aspects of this control law. ^While actuator saturation is shown to be a considerable problem for this type of controller, the flexibility of the backstepping design provides opportunities for improvement. ^In particular, the Lyapunov function is modified so that the growth of integrated error and the rate of change of parameter growth are both reduced, when surface commands are growing at a rate that will likely saturate the actuators. ^In addition, the deadzone technique from robust linear adaptive control is applied to improve robustness to turbulence. ^(Author)