Concept development of a multi-vehicle system for an operationally responsive mission

Draper Laboratory has developed a framework that describes engineering problem solving for conceptual design. The framework serves as a guide for conducting the difficult and important early stages of design, and does so regardless of concept domain. Further, it provides the organizational structure for a catalog of methods that can be collaboratively used to find solutions to complex problems. This paper documents the efficacy of the framework and method catalog against an Operationally Responsive System (ORS) problem. Responsive missions incorporate various potential vehicle fleets, diverse environments, rapid changes, and numerous goals. Designing a system to meet these needs is a much larger problem than simply designing a lone vehicle to meet a nominal, steady-state operational scenario. By using the framework and selected set of methods to approach the problem, the design of an Operationally Responsive System is accomplished using the following methods for successive solution types. Analysis is carried out at the System Solution level to frame the problem statement and compile stakeholder-derived attributes. Pugh analysis is used to compare dissimilar concept alternatives and down-select among them. At the Architecture Solution level, Object-Process Network (OPN) is used to fully explore a design space of low-order models based on aircraft, satellite, and distributed swarm concepts. Finally, the particle swarm optimization (PSO) method is implemented at a more refined level of modeling for Parameter Solution types with more detailed aircraft and satellite models, and a sensitivity analysis based on the results of an analysis of variance (ANOVA) study provides insight into the robustness of the design. Composite results from System, Architecture, and Parameter studies indicate that an aircraft in the class of a catapult-launched unmanned air vehicle (UAV), used in conjunction with a two-or three-plane Walker constellation with three satellites per orbital plane- , is a system design that performs well with respect to the stakeholder-derived attributes of the system. From ANOVA results, takeoff gross weight is identified as an important design variable for the aircraft concepts, and a sensitivity study on takeoff gross weight for the Pareto front designs shows that the small UAV-class designs are relatively insensitive to variation in this variable.