An adaptive reconfigurable longitudinal trajectory control applied to the damaged space shuttle for approach and landing

This paper presents an adaptive reconfigurable longitudinal trajectory control system applied to the damaged Space Shuttle for un-powered approach and landing. The controller is decomposed into four feedback loops: pitch-rate, angle-of-attack, flight-path-angle and altitude loop, among which the altitude loop is in the outer most and the pitch-rate loop is in the inner most. The pitch-rate loop is based on dynamic inversion technique and the other loops are in a backstepping control scheme. The onboard models used by dynamic inversion and backstepping are linearized models at some equilibrium points, and inversion model errors are compensated by online learning neural networks. The results of high-fidelity simulation indicate that the control system can maintain desirable stability and performance properties in the presence of wing damage.