Recent Design and Flight Test Experiences with Nonlinear Control Methods

This presentation aims at giving an overview of recent activities in the Design and Flight Testing of Nonlinear Control Methods at the German Aerospace Center (DLR) – Institute of System Dynamics and Control. Starting with an introduction to Nonlinear Control Methods, an overview of the implemented and tested methods is given – ranging from classical Nonlinear Dynamic Inversion to its incremental relatives Incremental Nonlinear Dynamic Inversion Control, Incremental Backstepping Control, Servo-Current-Control and finally Linear Parameter Varying Control. These methods have been implemented, qualified and successfully tested aboard a CS-25 qualified aircraft (Cessna Citation II, PH-LAB operated by TU Delft/NLR). This research platform features a FBW system with access for experimental Flight Control Law architectures, as well as DLR’s future ISTAR research aircraft, are presented. The respective flight test results of these four campaigns and respective conclusions wrt. lessons-learnt and future possibilities are discussed