Prescribed performance-based low-computational cost fuzzy control of a hypersonic vehicle using non-affine models

A novel adaptive fuzzy control approach with low computational costs is addressed for the longitudinal non-affine model of a generic hypersonic vehicle subject to parametric uncertainties, capable of guaranteeing that altitude and velocity tracking errors exhibit prescribed performance. A new performance function is devised to impose preselected bounds on the transient and steady-state tracking error performance, and then a transformed error is constructed, which converts the original constrained system into an equivalent unconstrained one for the simplicity of control designs. Furthermore, a simplified fuzzy controller is exploited for the altitude subsystem, eliminating the issue of explosion of complexity that is associated with back-stepping control. For the velocity subsystem, a prescribed performance-based proportional-integral controller is utilized. The special contributions of the proposed control strategy are that it can guarantee altitude and velocity tracking errors with desired transient and steady-state performance, and meanwhile the computational load is quite low. Finally, numerical simulation results are presented to verify the efficiency of the design.