Robust synergetic design of structural dynamic engine out controllers in parameter space

Engine out is a design criterion for a large transport aircraft from the vi ewpoint of Eight safety, handling qualities, and structural dynamics. A str uctural dynamic engine out controller covers these aspects, especially the reduction of the loads level at the vertical tail. It is designed by a new robust synergetic design method, using Ackermann's parameter space method ( Ackermann, J., Robust Control, Springer-Verlag, Berlin, 1993, Chap. 11, pp. 307-353). It allows the combination of different controller structures, ea ch of which satisfies specific requirements. This combination of controller s robustly satisfies all of the multidisciplinary requirements. Here, three controllers are combined: a standard lateral controller and a proportional -integral controller for safety and handling qualities and a structural dyn amic controller, which robustly decouples the shear force at the vertical t ail from the yaw rate. This unilateral decoupling controller achieves an ea rly efficient yawing moment compensation before the pilot. The controller c onsists of a feedback of the yaw rate to the rudder. Thereby, critical Eigh t and load conditions due to a delayed overreaction of the pilot are preven ted. The three controllers are characterized by eigenvalue regions for the closed-loop system. These Gamma regions offer compromises between the confl icts in design goals. Using the parameter space method, this approach yield s a set of robust controllers. A controller is selected and simulated on a nonlinear model.