Design of controller switching scenario for reusable launch vehicle with elevon jamming failure

When Reusable Launch Vehicles (RLV) return to earth, it flies just by gliding without thrust. In this phase, one of the most likely and important faults to occur in the airframe is a jamming of the elevon. To tolerate this failure, the flight control system must keep stability and performance during such a failure. One of the effective ways to overcome this problem is to switch the controllers based on the information of the detected failure in the plant. Generally speaking, the controller must have integrators so as to yield the zero steady-state error for the controlled output even if there exist some perturbations in the plant dynamics. In this paper, the design of controller switching scenario is addressed especially focusing on the decision of the controller state at the instant of switching the controllers with integrator. Then, the proposed switching scenario is applied to the control of ALFLEX (Automatic Landing Flight EXperiment), which is the automatic landing experimental vehicle being developed for RLV, considering the occurrence of the jamming fault. Some simulations are shown to verify the usefulness of the proposed idea.