Unmanned Vehicle Systems (UVS) are reaching new levels of functionality and performance, and it’s not just for air vehicles either. Ground and underwater UVS programs are all taking advantage of the higher-performance computing platforms that are using highly integrated, multicore processors; faster and larger DDR and flash memory; as well as integrated I/O. Additionally, remote I/O subsystems are being implemented to distribute the processing power closer to the sensors and use packetized message passing — with multiple levels of security (MLS) — back to a smaller central vehicle and mission management computer.
Traditional vehicle platforms had split the vehicle management computing functions (flight surfaces, engine and fuel controls, etc.) and mission management computers due to the overall expense of the computing hardware platforms and the costs to develop the software. Today, however, these hardware functions are being combined and then redistributed around the vehicle, significantly reducing size, weight, power, and cost (SWAPC), due to the density and performance improvements in the underlying processing technology (Figure 1).
From Air to Sea: Expanded Applications
The available computing performance and SWAP-C optimized systems have caught the eye of DARPA and other research agencies, which are experimenting with using wireless in traditional “wire-only” defense and aerospace applications. Other areas of unmanned systems innovation include building upon existing vehicle platforms to extend the function of a single vehicle. For example, a fighter jet may have several UVS synced up to its inflight control center, extending its reach from one large aircraft to include several smaller units that act as a mini army, all working together and being controlled from one location. This effectively extends the amount of airspace one craft can cover (Figure 2).
Underwater is another vast area for military vehicles to monitor with a limited number of vehicles. Applying this same “mini-army” philosophy, one large carrier could manage several smaller submersed vehicles that can carry supplies to other sea craft or even stealthily gather intelligence and report the data back to the mothership.
With the growing electronic density and enhanced communication profiles, UVS are offering a much more extended reach for military operations. But the data being transferred holds much larger security implications if it becomes compromised. So, in addition to mitigating size, weight, and power, many other critical design considerations are brought to the forefront. Data security and mission assurance, as well as signal integrity and reliability, are major focal points to implementing these new, more advanced unmanned systems.
Hacking, jamming/disrupting, or altering any wireless connection handling sensitive military information requires critical considerations, since compromised data can have a major impact on the outcome of the next engagement theater or battleground. So, where is the balance between security and performance, as more data is pumped into these systems and UVS growth continues?
Multicore Is Multi-Beneficial
Driving the higher densities of these computing systems are multicore processors. Their inherent ability to increase functionality and performance in roughly the same real estate footprint makes them a natural progression in the evolution of integrated embedded computing. And in a UVS, space is at an especially high premium.
The advent of multicore processors from Intel and Freescale, combined with the use of multicore ARMs in nearly every smartphone, means multicore processors are here to stay. And integrating the memory crossbar switch and caches into the processor silicon eliminated the bottleneck of memory bandwidth limitations, removing it from the performance equation altogether.
Faster and larger memory has fueled more software developer creativity and more functional and capable systems. And underlying operating systems and improvements in portable software architectures have simultaneously advanced to finally start meeting the promises of true portability and application auto-level loading by supporting virtual memory, multi-user configurations, and multi-processing utilizing parallel execution of applications.
Applying this high-speed, multi-core technology from the enterprise to the PC has provided a wide and more diverse tool chain to enable a robust application development environment, which makes for faster, enhanced parallelism. The computing systems align better with one another, allowing for more complex computation to be effectively managed within the system. As data requirements continue to advance, throughput, as well as proper data handling, are critical tasks that must positively contribute to system reliability.
Of course, the application will always dictate the processing functionality to solve the initial design problem, and small form factors can carry with them lesser functionality in both performance and I/O. But the need for intensive, high-speed data, in real-time, in areas such as sensor fusion, melding and digital alignment of tactical area maps, camera vision, infrared, radar, or sonar, requires the shear processing horsepower to get the job done in the allotted time needed for the application.
Mitigating Design and Cost Challenges
Because they are growing in diversity and application, unmanned systems generally have a wide, varied mix of sometimes conflicting requirements. To best meet the needs of developers, system manufacturers need to take stock in what end users are looking for and apply these insights in R&D. Once collected, this critical information can be applied to next-gen products and systems designed to meet the majority of current needs and demands using more off-the-shelf products, which bring with them less costly customization.
Budgets are tight in just about every industry. In military and defense, system engineers need to maximize every dollar spent to position their systems with greater flexibility to expand capabilities with the latest technology at the highest TRL (Technology Readiness Level). This is what brings market leadership and value to their end-customers. And by tying together the hardware and software platforms, integrated mission systems’ prognostics and automated diagnostics on unmanned systems open a whole new era of cost savings for the armed forces, potentially saving millions of dollars in maintenance and sustainment. Instead of forcing a system replacement into theater because a maintenance manual somewhere 5,000 miles away says "it’s time for an engine or C4ISR pack change," vehicle and mission platforms can use their own intelligence to predict their own maintenance schedules.
Unmanned systems are no exception. In fact, they have even more demands placed on them. Removing the operator enables the vehicle to be far more condensed in size. But this means the electronics are expected to fit into tighter, more constrained areas, while providing even higher control and mission-critical functions.
Managing heat in these highly dense, highly integrated systems starts at the IC and works its way out to the external environment. The trick is to truly understand the subtle nuances presented by the vehicle platform to the embedded computer device. Designers need to be able to minimize the internal thermal impedances from the active devices out to the real world in the most cost-effective and least complicated ways (Figure 3).
By their nature, unmanned systems require wireless data to be transmitted from vehicle to control center, regardless of whether the system resides in the air, on the ground, or underwater. Because there is no physical operator onsite, the UVS needs to reliably communicate with the epicenter of the system. Military and defense environments handle extremely sensitive intelligence that, if intercepted, could compromise critical missions or provide classified information to improper recipients. And the DOD isn’t the only entity concerned with protecting mission data.
System security is getting the same level of attention in the defense and aerospace markets as the commercial market, now that “nefarious other countries” are busy hacking into our government and contractor web sites and databases. RTOS providers (Wind River, GreenHills, Esterel, etc.) are providing multiple levels of security in their Ethernet stacks and processor core hypervisors to shut down any potential backdoor threats or malicious software embedded in JAVA scripts, etc. These heightened security profiles need to balance the transmission of the right information to the correct recipients from unmanned systems, without negatively impacting the specific application or intended mission results.
Looking to the Future
Increased usage of inter-processor communications, MLS, and data encryption will continue to rise quickly and efficiently, passing multiple gigabytes-per-second of data between local (onboard) nodes and nodes across board boundaries via high-speed copper, then optical pathways as the experience of implementing and using optical fiber gains momentum. And without stretching the imagination too far, cheaper multicore processors and larger volatile and nonvolatile memory will be the norm for nearly all applications, with operating systems and apps taking advantage of the huge increases in capacity and parallelism. Prices of the processors and memory will drop quickly as demand increases almost exponentially across all markets — commercial/consumer, industrial, and defense.
Look at the figurative explosion of the self-stabilized toy drone market using the same internal semiconductor GPS receivers, accelerators, magnetometers, and MEMS (Micro-Electro-Mechanical Sensor) gyros as those used in today’s smartphones. In just the past year alone, this trend has proven to be a viable predictor of the new smaller, lighter, and less expensive inertial navigation capabilities now available to the UAV/UAS defense contractor.
As silicon and other semiconductor processing platform technologies continue to grow, evolve, and advance, their usage will become more commonplace in everyday life as well. And as the software operating systems and development tools also progress, applications will only be limited by the programmers’ imagination, not the hardware platform underneath. These technology advances will be incorporated into cars, trucks, trains, and eventually flight-critical functions within aircraft, manned spacecraft, and UVS.
This article was written by Doug Patterson, Vice President, Military & Aerospace Sector, Aitech Defense Systems, Inc. (Chatsworth, CA). For more information, Click Here .