Piloted Evaluation Results of a Nonlinear Dynamic Inversion Based Controller Using Online Physical Model Identification

Introduction

As the survey of major aircraft accidents and incidents in Chapter 1 has shown, it is sometimes still physically possible to control a damaged aircraft while components such as control surfaces, engines or parts of the structure have failed. In some cases, (differential) engine control was used by the pilot to replace conventional control via the ailerons and elevators due to loss of the hydraulic system. In other cases, some control surfaces may still be operating to replace the failed ones. This redundancy can be exploited by an automated reconfigurable system which identifies the remaining control options and drives the available surfaces. Ideally, the system would also be able to cope with unforeseen failures and adapt itself accordingly. If the system takes the form of a manual fly-by-wire flight control algorithm, as opposed to a fully automatic system, the requirements on the (degraded) handling qualities also need to be taken into account. The system must provide the pilot with good handling qualities in normal flight conditions and acceptable handling qualities in failed conditions.