Robust Gain Scheduled Longitudinal Control of the ADMIRE Using Parametric Robust H∞ Control

To evaluate the benefits of structured parametric robust H∞ control a synthesis using this method is completed on a non-linear highly agile aircraft, called the ADMIRE. A gain scheduled two stage feedback controller with a feed-forward was used to design a pitch rate control augmentation system (CAS). The first stage focused on disturbance rejection while providing sufficient margins, while the second stage focused on the performance of the system. To compare the effects of parametric robust H∞ control three sets of controllers where synthesized, one nominal with no parametric synthesis, one with only the feedback controller synthesized with it and finally one system with both. The results show a clear trade-off between robustness and performance. The controllers synthesized with parametric synthesis greatly decreases the effects of uncertainty in disturbance rejection and tracking allowing for a more robust design