Discrete-time gain-scheduled model-matching flight controller using inexact scheduling parameters

This paper concerns the design problem of discrete-time gain-scheduled flight controllers for the lateral-directional motions of an airplane. In our design, equivalent airspeed is set as the scheduling parameter, but its values are affected by measurement errors due to its location (so-called “position error”) and finite resolutions. To accommodate these errors, we propose a design method for gain-scheduled controllers, in which only inexact scheduling parameters are supposed to be provided, by incorporating constant scaling matrices into an existing design method for the reduction of conservatism due to multiple uncertainty blocks in small gain theory framework. We design two gain-scheduled flight controllers, one is designed by our proposed method and the other is designed without consideration of the uncertainties. We conducted flight tests and illustrate the effectiveness of our method by comparing control performances of two controllers.