PI-Based Fault Tolerant Control For Fixed-Wing UAVs Using Control Allocation

The fault-tolerant control of fixed-wing unmanned aerial vehicle in the presence of actuator failure is investigated. A longitudinal and lateral proportional + integral + derivative control structure is used in combination with sequential least squares to develop the virtual control for the unmanned aerial vehicle with redundant actuators as well as dynamic uncertainties. The proportional + integral + derivative control structure ensures that the unmanned aerial vehicle has good stability and tracking performance under normal operation. The control reallocation makes sure that, once a failure occurs and has been detected and isolated, the virtual control may be redistributed among the remaining relevant actuators with the inclusion of rate and amplitude constraints. The effectiveness of the proposed control methodology is illustrated by simulation.