A modular adaptive control design with ISS analysis for nonminimum phase hypersonic vehicle models

Abstract

Air-breathing hypersonic vehicles typically exhibit a nonminimum phase behavior when altitude is controlled via lift generation. This phenomenon prohibits the use of classical inversion-based control techniques. Dynamic models of these vehicles are also subject to parametric uncertainties and unmodeled dynamics related to flexible effects of the fuselage. In this paper, we present a modular adaptive control method that achieves asymptotic setpoint tracking in both airspeed and altitude using thrust and elevator deflection as the only control inputs for a generic longitudinal model of a hypersonic cruise. The nonminimum phase problem is overcome through output redefinition, with altitude controlled by pitching moment. The internal dynamics, flight path angle, and altitude are then stabilized by saturating the interconnections and exploiting local stability properties. A new technique for the use of saturation functions in error coordinate is presented. The adaptive controller for altitude uses a pitch rate observer combined with projection. This control augmentation decouples the parameter estimation errors from internal dynamics, allowing for the use of small-gain arguments. Simulation results from a vehicle model with flexible effects and parametric uncertainty are included to demonstrate control effectiveness. KEYWORDS adaptive control, hypersonic vehicles, input-to-state stability, nonminimum phase systems 816

Fault estimation and compensation for hypersonic flight vehicle via type-2 fuzzy technique and cuckoo search algorithm

“…T , and x u ðxÞ ¼ ½x 1 u ðxÞ x 2 u ðxÞ Á Á Á x M u ðxÞ T are the fuzzy basis functions derived by the following methods…”

“…Hypersonic flight vehicles (HFVs) refer to vehicles that travel at a velocity greater than 5 Mach. 1 Such technique provides a reliable and cost-effective means for access to near space and has attracted great attention owing to their potential civilian and military applications such as prompt global response. 2,3 Since HFV works in a harsh environment where flight conditions and parameters often change radically, faults may occur in actuators such as elevators and rudders.…”