Flight testing of an structured H-infinity controller: An EU-Japan collaborative experience

This article presents the results from the first flight campaign undertaken within the frame of a collaborative EU-Japan project aimed towards the technological maturation of advanced aircraft guidance, navigation and control techniques. A control design (developed and flight tested by JAXA several years ago) was selected as the baseline system and objectives. This baseline design was based on a two degrees-of-freedom structure aimed at gust suppression in the feedback part and handling qualities model-matching objectives in the feedforward part. A newly developed controller uses this legacy interconnection and objectives and applies the Structured H-infinity control design approach with the goal to demonstrate the latter's potential to fulfill the same objectives while reducing the controller's dimension. The flight tests results presented show that this was successful and that both controllers' behavior are mostly indistinguishable, but with the new controller at half the dimension of the baseline.