Reconfigurable Flight Control Designs With Application to the X-33 Vehicle

Abstract Two methods for control system reconfiguration havebeen investigated. The first method is a robustservomechanism control approach (optimal trackingproblem) that is a generalization of the classicalproportional-plus-integral control to multiple input-multiple output systems. The second method is acontrol-allocation approach based on a quadraticprogramming formulation. A globally convergent fixed-point iteration algorithm has been developed to makeonboard implementation of this method feasible. Thesemethods have been applied to reconfigurable entry flightcontrol design for the X-33 vehicle. Examples presenteddemonstrate simultaneous tracking of angle-of-attackand roll angle commands during failures of the rightbody flap actuator. Although simulations demonstratesuccess of the first method in most cases, the control-allocation method appears to provide uniformly betterperformance in all cases. Nomenclature A state plant matrixb elements of BB control plant matrix Aerospace Engineer. Member AIAA. (661) 258 3726."_Associate