With an impressive track-record of development and production of integrated rugged subsystems for airborne and land vehicle platforms, Curtiss-Wright Controls Embedded Computing has demonstrated its depth of experience and capability in such diverse fields as motion control, navigation, flight control, network-centric communications and mission computing. Few COTS vendors get the opportunity to participate in the complete project cycle from  proof-of-Concept, to Low Rate Initial Production, to Production, offering subsystems based on their own product lines. Curtiss-Wright is in the commanding position to apply the experience gained during each phase back into its COTS products and its development processes to continuously improve performance and reliability.

Complementing the industry’s broadest range of COTS embedded computing modules, based on the VME and CompactPCI bus standards, Curtiss-Wright’s integration capability can be leveraged where time is critical, where key internal resources cannot be made available, or where certain parts of a project are outside the scope of internal expertize. Our specialized application knowledge gained over many embedded subsystem developments plus our intimacy with the off-the-shelf hardware and software products of Curtiss-Wright and many other 3rd party COTS vendors, can be combined to offer a more cost-effective package than an in-house solution. This saves the steep learning curve up-front and the long-term commitment to the support infrastructure required for the maintenance and repair of the deliverable equipment.

The Global Hawk is a high altitude, long endurance unmanned aerial reconnaissance system which provides military field commanders with high resolution, near real-time imagery of large geographic areas. In 2005, these vehicles were delivered to several divisions within the Armed Forces and the U.S. Air Force plans a total of 51 in the near future.

Curtiss-Wright supplies the Sensor Management Unit (SMU) for the Global Hawk platform. The SMU interconnects the sensor suite with the satellite and ground communications systems. Taking advantage of Curtiss-Wright’s existing expertise in open-architecture rugged COTS electronics, the SMU provides a common interface between the sensor payloads and the rest of the aircraft systems. This enables sensor payloads to be easily redefined and changed without impacting other aircraft systems.

The vehicle’s flight control, vehicle management software and navigation functions are controlled by two Integrated Mission Management Computers (IMMC) developed by Curtiss-Wright in California and delivered to prime contractor Northrop Grumman. The IMMC combines data from a Global Positioning System (GPS) and an Internal Measurement Unit (IMU) and then sends control instructions to an Inertial Navigation System (INS)supplied by Litton Systems. The accuracy and reliability of the IMMC was demonstrated when a Global Hawk made the first non-stop flight by an unmanned aircraft across the Pacific Ocean, flying from Edwards AFB in California to the RAAF base at Edinburgh, South Australia, a distance of 7,500 miles, in 23 hours. Global Hawk is the only unmanned aerial vehicle certified to fly in controlled US airspace.

Although our subsystems are predominantly comprised of COTS modules and, in some cases, additional customerfurnished equipment, they are developed and tested to specifications that are unique to each project. Subsystems may be integrated to the level of complete end-user functional and environmental compliance or they may be supplied as an application-ready enclosure with all modules fitted, tested and ported to a real-time operating system. Other levels of integration are possible including fully functional Built-in-Test (BIT), porting of existing application software, or just fitting modules to a pre-wired enclosure.

Some end-use applications may stretch the environmental envelope slightly beyond an individual product’s published specifications. Because COTS products are designed to generic environmental requirements, individual products may comfortably exceed these generic specifications in the right conditions. Our unrivaled access to design data and shared resources within Curtiss-Wright provides the confidence to meet special end-use environments and unique customer applications. Whatever the level of integration, Curtiss-Wright ensures compliance to a customer’s requirements through extensive programs of analysis and testing of the completed article. Highly Accelerated Life Testing (HALT) and full qualification programs are also available to provide further confidence in the quality of engineering and the robustness of the deliverable subsystems.

Most subsystems can be configured using off-the-shelf modules. However, there will always be unique requirements that cannot be met without either some adaptive engineering of an existing product or development of an entirely new module to suit a specific project’s requirements. We share common engineering standards across Curtiss-Wright for designing products for rugged environments, plus the results of research into component technology, Printed Wiring Boards (PWB), solder joint reliability, thermal management and software development. All of these can be leveraged to provide the best and most affordable solutions for specialized requirements. Our capability extends beyond derivative engineering of COTS products into complete custom solutions if the available space or shape precludes open-systems standards such as VME or CompactPCI. Similarly, our deep understanding of many control-based applications makes it possible to offer innovative COTSbased technology replacement solutions for complete obsolete or unmaintainable subsystems already in the field.

With a long tradition of software development to DODSTD-2167A and MIL-STD-489, Curtiss-Wright has evolved software development and configuration management standards in accordance with IEEE 12207 with additional audit and QA derived from our compliance to ISO 9001 and SAE 9100. In addition to the integration of BIT, a fully integrated subsystem will include a real-time operating system (RTOS), usually selected from Wind River’s VxWorks/Tornado, GreenHills Software’s INTEGRITY or Linux. Drivers and run-time support functions and libraries supplied with the Single Board Computer (SBC) and supporting PMC and I/O modules will be integrated and modified as necessary to meet the subsystem’s functional requirements.

Not all applications require the rich functionality and complexity offered by an off-the-shelf RTOS. Less complex subsystems and those that may require in-depth analysis or proof of design integrity for safety-critical applications will benefit from a much simpler operating system. Curtiss-Wright has developed an operating system in-house for this class of application that provides simple, deterministic scheduling and also meets the exhaustive requirements of RTCA DO-178B. Using this operating system and the controls and procedures used during its development we can offer complete subsystems with the specifications, plans and artifacts necessary for presentation to certification authorities.

Enclosures can be custom designed to suit specific applications or may be derived from many of the standard designs already available. Overall system performance requirements generally dictate the choice of the embedded computing standard to be used; 6U VMEbus for the greatest performance and functionality, while 3U CompactPCI is recommended where space, weight and power dissipation are critical factors. Subsystems for use in the harshest of environments such as aerial or tracked ground vehicles use conduction cooling for the VME or CompactPCI modules which dissipate heat into the enclosure by conduction. Enclosures can be cooled by many means: free-air convection, forced air, pumped liquid, or even conduction cooling into the vehicle’s structure. The choice will vary from platform to platform depending on what form of cooling is available and how much heat is to be dissipated.