Design and Implementation of a Fault-Tolerant Flight Control Law for an Ultralight General Aviation Aircraft

Kurzfassung

Ultralight general aviation aircraft are common among retired commercial aircraft pilots and flying enthusiasts. However, the small amount of regulations around these aircraft makes them more susceptible to failure. The current solution when failures occur involves deploying a parachute which results in damaging the aircraft and can drift it into dangerous areas. This work is inserted in a project that aims to enable aircraft to autonomously return to safety in case of failures or emergencies instead of deploying a parachute. A Hybrid Nonlinear Dynamic Inversion (hNDI) controller is developed, with robust control design for the linear gains, along with a control allocation method to handle multiple controllable inputs. By employing mu-synthesis to design the gains, external disturbances and modeling uncertainties are expected to be handled. For the control allocation, ganging and optimization-based methods are developed to handle failures such as actuators getting stuck. The results show that the controller performs well in handling these scenarios, however, more comprehensive tests are needed to meet aeronautic regulations and be deployed on aircraft systems.