Sensitivity Analysis and System Attribute Importance for Conceptual Aircraft Design with the Advanced Morphological Approach

Abstract

The search for a rational design subspace of aircraft configurations can be addressed by using the advanced morphological approach (AMA). It allows the decomposition of design problems into functional and/or characteristic attributes and their technological implementation options. These are systemized in a morphological matrix (MM). Based on expert evaluations of each option, an exhaustive space is generated containing option combinations as possible solutions. Therefore, extensive MMs lead to immense solution spaces that are hard to analyze. However, removing attributes without justification might leave potential rational solutions out of scope. In this context, a sensitivity analysis technique is suggested based on analysis of variance (ANOVA) tests for use with the AMA. It can be applied to assess the sensitivity of solution scores against the attribute options and their importance. As a result, optimization of the MM and solution space can be achieved and improvement proposals can be drawn for future problem statements with the AMA. This is demonstrated on the data from a previously conducted AMA workshop on the conceptual design of a search and rescue aircraft.

Structured Expert Judgment Elicitation in Conceptual Aircraft Design

“…For the first development iteration of the enhanced AMA, a first workshop was conducted and described in Reference [12], where the conceptional design of a search and rescue aircraft was studied. The current article discusses the conduction and results of a second workshop which aimed to consider the lessons learned and test new ideas.…”

“…Based on this approach, a methodology for organized expert panels shall be studied, which would evaluate the MM options and serve as a scientific ground for the generated solution space. A first iteration of the methodology testing has already been conducted within a first workshop on the design use case of a search and rescue aircraft (SAR), described in detail in Reference [12]. As a result, a solution space containing 54 configurations was generated which yielded a multi-criteria optimum implementing hybrid aerodynamic/aerostatic lift generation, fully hydrogenbased non-distributed propulsion and wing morphing.…”

“…However, the thorough conduction of such routines might be applicable for the elicitation of a relatively small amount of variables simply due to time constraints and limitations related to participant engagement and their attention span. This was experienced during the first [12] and second workshop of the current project.…”

“…In order to model the uncertainties incorporated into the experts' subjective answers, the concept of ordinary fuzzy number is used for each technology comparison. The benefits of this approach and the justification for its use within the AMA are described in more detail in References [4,12].…”

“…The hierarchy used for the current workshop is exhibited in Figure 4. The organization of options and criteria in levels has been executed analogically to the problem structuring in the first workshop (see Reference [12]). The options from the same attributes are compared regarding each criterion of the level above.…”