The use of Unmanned Aerial Vehicles (UAVs) in the military has skyrocketed as UAVs have proventheir military worth in Afghanistan and Iraq. UAVs are credited with saving soldiers' lives while improving battle space efficiency, making these aircrafts a vital component in the warfighter's toolbox. However, with unmanned vehicles becoming a mainstay of battlefield and reconnaissance operations, equipping these aircraft with a custom, proprietary computing architecture is costly and time-consuming-two unacceptable consequences for military sub-contractors.

To alleviate this concern, the use of a common computing architecture in UAVs is becoming the obvious solution for many aerospace manufacturers, such as Aurora Flight Sciences. For Aurora, a designer and builder of robotic aircraft and other advanced aerospace vehicles for scientific and military applications, the advantage of using a common computing architecture is clear-a high reuse fraction. By leveraging the computing architecture in multiple aircraft, Aurora reduces costs and improves efficiency, which empowers their ability to design and build a range of unmanned platforms designed to meet the diverse needs of military, law enforcement and homeland security personnel.

Designing the ACMC

As a common computing architecture was necessary to serve as the foundation for Aurora's future aircraft, Aurora needed to find a robust computing solution that could meet stringent military requirements while withstanding the different environments encountered by various UAVs. In addition, the mission computer needed to support a superset of features and requirements to meet all the different UAVs technical demands.

Aurora began working with Parvus to develop the Aurora Common Mission Computer (ACMC) (Figure 1) as part of Aurora Common Avionics Components program. From the outset, the goal of developing the ACMC was to use industry standards to support long-term system evolution and reliability. The DuraCOR mission computer product line from Parvus met this goal as it offered a modular open-architecture computing platform that could be adapted to its various UAVs. However, the DuraCOR 810 model that Aurora was eyeing was too large for its needs. By shrinking the mechanical form factor and selecting miniaturized components, Parvus created the ACMC, which has since been added to Parvus' standard product offerings as the DuraCOR 820.

New-Life Reusability

Important to Aurora was the concept of new-life reusability for this computing subsystem to accommodate the demands of future aircraft mission profiles and payloads. To meet this requirement, the ACMC was designed with excess computing power and additional throughput over current application requirements. By building in margin for growth upfront, the ACMC could accommodate future software loads and advanced processor throughput. The resulting ACMC/DuraCOR 820 is less than 3.0 inches in height and 3 lbs in weight and features a conductively cooled 1.4 GHz Intel Pentium M processor-equivalent to a 2.8 GHz Pentium 4 performance-and a solid-state disk preloaded with a Linux or Windows XP Embedded operating system.

Rugged, watertight, ultraminiature Mil-spec performance connectors bring out dual 10/100 Ethernet network connections, 3x USB, 2x RS-232, video, DIO, keyboard and mouse. This robust combination of function and small form factor ruggedness enables the unit to support a wide range of field applications, including Command and Control (C2) On-the-Move, Unmanned Vehicle Operator Control and C4ISR Situational Awareness.

Like its hardware, Aurora also develops its software for unmanned aircraft systems with high reuse functions in mind. Although each UAV serves a different purpose, Aurora minimizes the customization of its software by architecting its code to apply to multiple programs. By developing for reuse and modularity, Aurora has simplified its design procedures to ensure high value and increased efficiency.

Ruggedizing ACMC for Multiple Platforms

As the ACMC is deployed in various UAVs that encounter different environmental and physical requirements, further testing and qualifications were required to ensure heightened durability. Testing under MIL-STD-810F environmental conditions (high altitude, thermal, shock, vibration, humidity) was completed, and a 28V avionics power supply compliant with MIL-STD-704E was integrated. To ensure the ACMC could endure high altitudes encountered by some of Aurora's latest UAVs, Parvus completed additional analysis and/or testing to ensure the unit could operate at up to 60,000 feet.

After the ACMC passed qualification testing, production units were installed and successfully flew on board the GoldenEye 80 vertical takeoff and landing (VTOL) aircraft (Figure 2) and the Excalibur turbine hybrid-electric unmanned air system (UAS) (Figure 3). In addition, the unit flew on board the fully autonomous conventional takeoff and landing (ATOL/CTOL) Chiron demonstrator based on a Cessna 337. These aircraft represent new classes of tactical unmanned air vehicles. The ACMC is also being considered for installation in Aurora platforms currently under development.

Figure 2
The GoldenEye 80 Unmanned Aircraft System (UAS) from Aurora Flight Sciences was designed to use a common mission computing platform (image courtesy of Aurora Flight Sciences).

Figure 3
The Excalibur UAV from Aurora Flight Sciences uses the Aurora Common Mission Computer (ACMC) (image courtesy of Aurora Flight Sciences).

COTS Development for UAVs

As UAVs have escalated from a niche technology to a key military strategy, the costs and risks associated with its computing architecture are heavily scrutinized. By leveraging COTS technology to sustain multiple UAV platforms, Aurora has proven that common computing architecture improves efficiency and provides the foundation for future growth. As commonality and commercial standards drive many of the military's programs, the further development of COTS products for UAVs will only help the warfighter improve mission efficiency.

Parvus
Salt Lake City, UT.
(801) 483-1533.
[www.parvus.com].