Robust Synergetic Design of Structural Dynamic Engine Out Controllers in Parameter Space

Abstract

Engineoutisadesigncriterionforalargetransportaircraftfromtheviewpointofe ightsafety,handlingqualities, and structural dynamics. A structural 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, each of which satise es specie c requirements. This combination of controllers robustly satise es 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 dynamiccontroller, which robustly decouplestheshear force atthevertical tail from the yaw rate. This unilateral decoupling controller achieves an early efe cient yawing moment compensation before the pilot. The controller consists of a feedback of the yaw rate to the rudder. Thereby, critical e ight and load conditions due to a delayed overreaction of the pilot are prevented. The three controllers are characterized by eigenvalue regions for the closed-loop system. These C regions offer compromises between the cone icts in design goals. Using the parameter space method, this approach yields a set of robust controllers. A controller is selected and simulated on a nonlinear model.