Development and Concept Demonstration of a Physics Based Adaptive Flight Envelope Protection Algorithm**This work was supported by a Marie Curie International Outgoing Fellowship (IOF) and the ACROSS project (advanced cockpit for the reduction of stress and workload) within the 7th European Community Framework Program.

Abstract

This paper discusses the development of an adaptive protection algorithm which is
\nbased on a physical approach, with the purpose to keep a closed loop aircraft with manual control
\nlaws within the actual safe flight envelope, even in the presence of failures or disturbances.
\nAdaptive estimation of the flight envelope guarantees that not only flap changes, but also
\ndamage (e.g. icing) and external disturbances such as wind can be taken into account. This
\nmethod is robust with respect to uncertainties in the estimates for the aerodynamic properties.
\nThis updated information is used in the flight control laws to prevent loss of control in flight.
\nThis development can extend the functional envelope of the nominal law and reduce the need
\nto switch from nominal to alternate law in the presence of certain failures. This algorithm
\nhas been applied on a fairly matched A320-type of simulation model and the setup has been
\nimplemented in the DLR Robotic Motion Simulator at the German Aerospace Center as a
\nconcept demonstrator.