Nonlinear Reconfiguring Flight Control Based on Online Physical Model Identification

This paper presents a study on fault tolerant flight control of a benchmark aircraft model. Reconfiguring control is implemented by making use of adaptive nonlinear dynamic inversion for manual and autopilot control. The weakness of classical nonlinear dynamic inversion, its sensitivity to modeling errors, is circumvented here by making use of a real-time identified physical model of the damaged aircraft. With help of the Boeing 747 benchmark simulation model, including the realistic component as well as the structural failure modes, it is possible to analyze the damage accommodation capabilities of the considered approach. In failure conditions, the damaged aircraft model is identified by the so-called two-step method in real time and this model is applied subsequently to the model-based adaptive nonlinear dynamic inversion routine in a modular structure, which allows flight control reconfigurations online. After discussing the modular adaptive controller setup, reconfiguration test results are shown for damaged aircraft models using a desktop computer as well as the moving base Simulation, Motion, and Navigation Research Flight Simulator of Delft University. These results indicate satisfactory failure handling capabilities of this fault tolerant control setup, for component as well as structural failures. [PUBLISHER ABSTRACT]