A Bi-Level optimization approach for technology selection

Abstract

Technology selection is a crucial step in the process of aircraft design. If the performance and economic requirements are not fulfilled for any combination of the design variables, new technologies need to be infused in the design. Typically, the designer has a pool of technology options. The technologies to be infused in the new design are to be selected from this pool so as to achieve improvements such as increased performance, reduced risk, reduced cost etc. Thus, it is critical to be able to perform a quick and accurate assessment of the available technologies in the early stages of the design process. However, if the set of available technologies is large, the designer runs into a huge combinatorial optimization problem. To tackle the problem, a systematic approach called Technology Identification, Evaluation and Selection (TIES) has been developed to choose the best set of technologies and arrive at a feasible and viable design solution. However, the issue of dealing with large combinatorial problems still remains. A new approach for tackling the same problem of technology selection was inspired from the TIES methodology and is discussed in this paper. This approach is based on identifying an optimal point in an intermediate variable space, that later on serves as the target point for technology selection. The new approach, called ?Bi-level approach? provides additional insights and expedites technology selection, thus rendering efficiency to the preliminary design process. After describing the bi-level approach, its application to an aircraft design problem is presented.