Nussbaum-based robust tracking control of flexible air-breathing hypersonic vehicles with actuator dynamics

摘要

This paper proposes an effective control scheme to address the robust tracking control problem of the flexible air-breathing hypersonic vehicle subject to actuator dynamics. The whole vehicle dynamics is decomposed into the velocity subsystem and altitude subsystem, and the nonlinear disturbance observer based dynamic surface control is employed in the controller design within both subsystems. In order to tackle the input constraints, different hyperbolic tangent functions are carefully designed to approximate the non-smooth saturation functions. The compensators are further introduced for saturation approximations with the Nussbaum function technique. Through Lyapunov stability analysis, the closed-loop system is guaranteed to be semi-globally uniformly ultimately bounded. Moreover, the tracking and estimation errors converge to an arbitrary small neighborhood around zero. Extensive simulation and evaluations verify the superiority of the proposed scheme.