An adaptive retrofit reconfigurable flight controller

In this paper we propose an adaptive retrofit reconfigurable control (ARRC) algorithm suitable for flight control applications. The algorithm is relatively simple and easy to implement, and assures that the control objective will be achieved despite the presence of the unknown loss of effectiveness of the control effectors. The proposed approach retains the existing nominal controller and adds a suitably chosen signal that assures that the desired closed-loop performance is achieved despite the failure. The approach is based on the properties of the system controlled by the nominal controller, and judiciously chosen adaptation signals. Performance of the resulting closed-loop system is illustrated through simulations of the F/A-18C/D aircraft in the presence of loss of effectiveness of multiple critical control effectors.