A UAV Design / Sizing Study from a System of Systems Perspective

Abstract

Traditional approaches to aircraft sizing focus on maximizing the performance of the individual airframe as a standalone system. Customers, such as the Department of Defense, have looked recently more towards all-encompassing solutions to large problems by using a System-of-Systems approach instead of maximizing capability from a single aircraft or similar monolithic system. Shrinking budgets call for making the most efficient use of existing assets and addressing capability gaps in broad frameworks. The result is that optimizing the aircraft alone may not provide the customer with needed capabilities or optimizing the aircraft alone may not make best use of the entire collection of aircraft to provide the capabilities in the most efficient manner. A fleet or collection of Unmanned Aerial Vehicles (UAVs) performing Intelligence, Surveillance, and Reconnaissance (ISR) missions provide an example of systems designed to operate with other independent systems as part of a system-of-systems. In this research, a fleet of UAVs will conduct surveillance over high terrain. The research investigates how to allocate existing systems along with a number of yet-to-be-defined UAVs. In this manner, the new UAVs may not be optimal for individual aircraft-based performance metrics, but they will enhance the capabilities of the fleet. Such a problem requires decomposition into a resource allocation problem , and an aircraft sizing sub-problem. The allocation problem uses a Design of Experiments (DoE) to select UAV fleet combinations to test by simulation using STK’s Aircraft Mission Modeler software package. The aircraft sizing problem uses an SQP algorithm and a Breguet endurance equation-based sizing code to predict the dimensions, weight and performance of the new UAV. Both a main effects approach and a response surface approximation approach show the tradeoff between fleet cost and area coverage, enabling the customer to select the optimal allocation of existing and new UAVs while also determining the key characteristics of the new UAVs that fit into this fleet. The new UAV, sized for this specific mission but from a System-of-Systems perspective, complements the UAV fleet, enhancing the capabilities of the UAV fleet while only occasionally replacing the existing UAV assets.