Six-Degree-of-Freedom Intelligent Control of Hypersonic Flight Vehicle

The six-degree-of-freedom control of hypersonic flight vehicles (HFVs) faces great challenges due to complex aerodynamics, inherent couplings, and multiple constraints. This article investigates the six-degree-of-freedom guidance and attitude control problem for unpowered gliding HFVs. The guidance loop is based on the predictor–corrector method with three improvements: intelligent prediction acceleration, path constraint accommodation, and no-fly zone circumvention. To quickly respond to guidance commands, three attitude channels (i.e., roll, pitch, and yaw) are completely decoupled by nonlinear dynamic inverse, based on which a high-performance low-complexity attitude controller is proposed. This benefits from the appropriate integration of barrier function and sliding-mode control, while design conditions of three alternative performances (i.e., asymptotic, exponential, and preset-time convergences) are discussed. Servo dynamics and physical constraints of aerodynamic control surfaces are also well handled.