Multigoal Programming for Structure/Control Design Synthesis with Fuzzy Goals

Abstract

This paper considers the simultaneous structure/control design synthesis of a wing with an active control system called the gust load alleviation (GLA) system. The introduction of fuzzy goals for both the gust-induced stress with the control system off and the structural mass is the primary focus in the present paper. A simple wind tunnel model excited by a random gust is studied. The thickness of a FEM beam element modeling the wing spar and the feedback control gain are optimized to maximize the fuzzy decision with the prioritized design requirements, e. g., the control system's stability characteristics, and the standard deviation of the gust-induced stress and control surface deflection angle with the control system on. The sequential linear approximation method is proposed to obtain the optimum solutions for nonlinear multigoal problems with fuzzy goals.