By J.R. Wilson
The U.S. Army and its service counterparts will move toward lighter, faster, and perhaps cheaper platforms in the next few decades, the influence of this transformation on vehicle electronics (vetronics) and on vehicle design will be substantial. In this move, vetronics incorporates everything from embedded training to advanced communications in a network-centric battle theater.
Smaller systems usually have more heat to dissipate, while power needs may increase as size and weight decrease. As the vehicles themselves become lighter, the components inside may need to become more rugged.
Vetronics means crew station technology, decision aids, robotics, a new concern called active protection, and the embedded aspects of networking for tasks such as working with unmanned aerial vehicles (UAVs) and unmanned ground vehicles (UGVs). All of these capabilities involve a lot of electronics.
"We are taking a systematic look at the application of vetronics for combat vehicles, which is not necessarily device electronics," explains Curtis Adams, associate director for vetronics technology at the Army's Tank-Automotive & Armaments Command (TACOM) RD&E Center (TARDEC) in Warren, Mich. "We look at systems architecture, embedded simulation, automation, robotics, telematics (getting data on and off the vehicle), and the crew station. We are beginning a robotic semi-autonomous program, working in conjunction with the Army Research Lab.
"In the wider sense, TARDEC has responsibility for other technologies in ground vehicles, such as electromagnetic or hybrid electric drives, Adams continues. "That applies to both the transmission and any other high-power loads on the vehicle. We also have the responsibility of engines, including more and more complex digital controls.
"Another major area is active protection. The lighter vehicles can't have Abrams-level armor. One way around that is to take targets out before they can hit you. Another is active protection, which detects incoming rounds and intercedes while they are still in flight. That requires a lot of sensors and electronic controls." Abrams refers to variants of the U.S. Army M1 Abrams main battle tank.
Networking is crucial for the next-generation Future Combat System (FCS), as a factor in keeping the lighter force from being outgunned and to coordinate forces in a way the enemy cannot match. "Previously, that was a good thing, but not mission critical," Adams says. "But FCS won't function properly without the network capability, so it becomes mission critical to the force."
The future of making all platforms part of a network-centric force and meeting the enhanced vetronics requirements of that force will depend heavily on commercial-off-the-shelf (COTS) components, ruggedized as necessary, to meet the harsh operating environment military ground combat.
"FCS will be the real test on having a common set of requirements across all the various platforms, manned and unmanned, ground and airborne, but all operating in the same battlespace," says Frank Willis, vice president for business development at the SBS Technologies Government Group in Albuquerque, N.M. "So from an overall electronics perspective, you would expect them to have a common set of environmental requirements across the board. It will be interesting to see what level of commonality does come out of it."
Nearly every aspect of electronics design and capability is being driven by commercial demand, not military requirements, leaving the cost-conscious U.S. Department of Defense with little choice but to meet those environmental requirements with COTS components.
"That will involve some parts screening for temperature range, then packaging, including some additional cooling compared to simple conduction cooling in the past. But we're not actually talking the kind of hits an Abrams gets, both from ballistic shock from enemy fire and the shock and vibration from its own weapons," Adams explains. "The lighter vehicles are not expected to take a direct hit and the guns will be smaller, although it may be possible the gunfire shock could be worse because the vehicles also will be lighter.
"The navigation systems will use both GPS and inertial navigation. The navigation requirement actually will be more stringent because they will be sharing data over the network and using it to help coordinate fire. So they will need to be more accurate than the Abrams and Bradley."
Ken Mick, director of vetronics and fightability for General Dynamics Land Systems in Sterling Heights, Mich., says the migration of COTS technology to meet military requirements has several benefits, such as relatively low power requirements. This means less cooling, less drag on the engine, and small wiring, leading to a small overall package that is easy to ruggedize.
"Vibration is a key element in ruggedization; tracked vehicles versus wheeled have differences in vibration," he says. "Other elements to consider include temperature ranges, which are the same on any military vehicle. So it actually should be easier to ruggedize on a wheeled vehicle."
Resolving those issues means enhancing vehicle capabilities through such major commercial markets as cell phones and portable computers, which have been driving all electronics.
"Imagine what the displays in a tank, now using mid-1980s technology, could be if modern laptop display technology were applied," Mick says. "And in terms of CRTs [cathode-ray-tube displays], compare the depth of that to an equivalent flat-panel display and the savings you could get in size, weight, power, and cooling. But you need to match a given sensor to a display, which is an integration effort.
"We're continuing to reduce the size of the electronics footprint. That relates back to the PC, comparing one built in 2003 versus one built in the 1990s. We are trying to take advantage of all the technologies that have come out of that arena. Of course, there will be some developmental costs associated with this effort."
At BarcoView Command and Control in Duluth, Ga., vetronics product manager Ed Fulmer says such changes in displays not only influence size and weight, but also the number of components, which further eases heat and cooling concerns. While the current design trend is to incorporate flat-panel displays based on liquid crystal display (LCD) technology, future systems instead may turn to OLED (organic light-emitting diode) technology, which has the potential to be even lighter.
"When procuring electronics, the Army and Marines define a specification for that product in which they identify environmental parameters that display must meet. If you look at the specs for an LCD today, they are the same as we had to meet with a CRT ten years ago. In many ways, it is easier to ruggedize an LCD, especially in terms of shock and vibration," Fulmer says. "When you look at reliability, the typical drivers are component count, operating temperature of the electronics and high voltage. A CRT has more components, runs hotter and has an extra high voltage to run the tube. So just the difference between LCD and CRT technology demonstrates a natural ability to improve reliability.
"When you think about the larger display sizes, say a 20-inch CRT versus a 20-inch flat panel, you're looking at the difference between a one- versus two-man lift. Not to mention the inside of a combat fighting vehicle, such as an Abrams or Bradley, has very limited space to get a maintainer into position. So the bigger the device, the more difficult it is."
There are limits to a fully COTS system for image processing on a military platform, however. While designers are taking advantage of certain elements, they also have to consider the quality of image processing for reconnaissance, surveillance, and target acquisition. The system requires a level of sophistication that can produce an intelligent, recognizable image from even a poor-quality signal.
While the latest commercial TV technology can produce an image that is better than what the human eye can see — especially at night — the military also needs to use special optoelectronic sensors that have higher resolution and longer range than a TV camera. Those optoelectronic sensors also will work with data from lasers, radar, and networked unmanned vehicles. To turn that into a clear and easily understood picture will require improved and adapted image-processing technology.
Another major change in FCS vetronics may include at least partial abandonment of the venerable MIL-STD-1553 databus, among other changes to more commercial modes.
"If you look at FCS as the transformation platform for the future Army and the technologies required going into it, the main databus in an Abrams is 1553 at 1 megabit per second; but with FCS, we're going to a gigabit Ethernet. A few years ago, using Ethernet in a major weapons platform was unheard of, so making that transition is fairly significant," says SBS's Willis.
"Those interconnects will be distributed and split up. Gigabit Ethernet will be the main databus for communications, but there also will be Fibre Channel. So there may not be one bus that fits all, however ideal that may be, because it just isn't reality. All are equal from a development view and have different processes they are being released in. There is a lot of legacy equipment that will have to migrate, so we will still have to contend with bus issues we want to get away from but will still be locked into."
Which may actually mean another reprieve for 1553, he adds.
"This is just another example of where 1553 has been around for decades and probably will be around for another 20 years because the legacy systems still have to be supported," Willis says. We've had an effort underway looking at high-speed 1553, primarily to increase the bandwidth capability of some of these legacy platforms. The processing element side is being upgraded, so by now you are piping the data down a 1-megabit-per-second pipe. As a result, we are looking at ways to yet again extend the life of 1553, going from 1 megabit per second to 100 megabits per second. That will come about and 1553 will be around for a long, long time."
Part of the weight, cost, and space savings on the FCS platforms will come from a change in computer schemes. For example, the Abrams has separate processors for the turret, hull, and fire control. It is very much a distributed architecture of several different black boxes. FCS, on the other hand, is placing heavy functional demands on one box for mission computing, fire control computing, embedded training, and digital map functions. These functions will load into one integrated computer with partitions to run separate pieces of software.
As that development hits the hardware side, operating systems also are undergoing a revolution, with some systems moving to Linux, which was not even considered for heavy force programs as recently as five years ago.
"The integrated C4ISR [command, control, communications, computer, intelligence, surveillance, reconnaissance] computer is a core integrated computing element across all platforms," Willis explains. "Embedded training computing requirements, simulation, mission rehearsal, maintenance publications all will be in the vehicle, from a digital perspective. And when you look at all that, it will require much more highly integrated and more robust designs. The throughput of the databuses, the pipe through which you are moving data fiber optics the speed and transferring of data will be much greater than ever before."
Cooling remains a problem, he notes, with a variety of new technologies under investigation, but none yet ready for fielding.
"Due to the amount of power that must come out of the systems, you have some limitations. A lot of applications are going with what they know today rather than investing in new technology, so induction cooling is still prevalent, but in the future there will be greater demand for alternative cooling," he says. "We support the spray cooling initiative and have some products that have been tested in that market. We've embraced the Marine Corps efforts on AAAV [Advanced Amphibious Assault Vehicle], although it hasn't yet been fielded."
The AAAV is the first system to experiment with liquid spray cooling of electronics, using evaporation for heat transfer (generally considered one of the most efficient methods). Coolants with a boiling point of 70 degrees Celsius, such as 3M Fluorinert, spray onto electronic circuitry operating at that temperature and cool the components by evaporation. The system extracts and condenses the resulting vapor, and then radiator tubes and fans remove heat from the liquid.
"The processing demands and power generation of these chips will only get greater and greater, so we have to put something out there that can handle the cooling requirement," Willis says, noting most of these systems do not accommodate an air flow capability. "Traditionally, most electronics have been VME and 6U in size. We've seen a major move afoot in a number of airborne applications and we suspect in certain ground vehicle applications, as well, where size, weight, and power are significant factors and 3U CompactPCI solutions have been well received.
"As these vehicles get smaller, you'll have to see some level of dynamic change occur within the systems" Willis continues. "It's like putting 10 pounds of stuff into a 5 pound can. All these vehicles have had weight problems; Abrams is a 70-ton tank. Getting the weight down and making the vehicles more mobile will mean shrinking the electronics into smaller packages, as well."
TARDEC's Adams says the size and weight of vetronics will be a greater concern in unmanned vehicles than manned because UAVs and UGVs have more stringent payload-to-weight considerations. They also will require a high degree of vetronics to handle autonavigation and other autonomous requirements.
"The intent and expectation is they will have some semi-autonomous capability, augmented, as needed, by a man," Adams says. "It needs someone to plan its mission, but it will be able to navigate in most terrains and environments, although in some cluttered environments, a human may need to engage. A human also will need to verify targets and initiate firing. The concept is not to have a full-time robot operator, but someone who can work with it in addition to other duties. The basic idea is to crate a 1-to-4 arrangement, although a higher-echelon UAV may have full-time human operators, as the Predator team now does.
"The remote operator may be in a manned ground system with another mission, such as recon, or in a command-and-control vehicle handling higher-echelon robots. FCS is highly flexible in how it will be able to organize for any given fight, so that would make the configuration with the ARVs [Armed Robotic Vehicles] easy to change."
FCS manned vehicles also will rely more heavily on vetronics for such applications as crew station technology, more variety for control, and perhaps some decision making as the number of human crewmembers aboard drops. Most will have a two-man crew, with a local vision periscope augmented by some indirect-vision displays for targeting and night driving. The vehicles also will be smaller than today's vehicles — about 18 tons for most of the manned ground vehicles (MGVs), such as infantry carriers, mobile direct fire combat systems, mortars, cannon, and reconnaissance. Most, if not all, are to include embedded training and networking capabilities.
"With reduced crew sizes and more reliance on off-board data communications and intra-vehicular communications which will reduce the amount of wiring and weight all will be driven by electronics. So the level of electronics computing required to handle all that will be tremendous," Willis notes. "The processing elements are getting much faster and that will continue. But just having faster processors isn't the whole solution. You also have to be able to move that data faster. InfiniBand, StarGen, RapidIO — those will all be involved in serving those applications.
"You have to be able to bring sensor data and other things into the platform visually and present it in 3D to the operators," Willis continues. "The resolution capability will make the operators' situational awareness capability that much better. With regard to the sensors from electro-optical to communications to radar warning receivers to countermeasures a lot of sensor applications on the front end have been using traditional DSP [digital signal processing] solutions. Recently, however, there have been a number of inquiries about using FPGA-based solutions as an alternative to traditional DSP because of greater flexibility, reprogrammability, cost, and so on."
Adams says leaders of the FCS lead system integrator team of Boeing in Anaheim, Calif., and SAIC in McLean, Va., are leaning toward gigabit Ethernet as a main system bus and to real-time Linux as its main operating system, although it is still early and that could change.
"Things that reduce its size will include crew station technology, high-speed external network, active protection (to get rid of armor), more precision from the inertial capability (which may actually be larger and more expensive units). As part of an integrated survivability suite, there will still be certain types of armor, countermeasures (such as jammers, decoys, smoke, etc.) and other classified elements that are still being worked."
The robotics autonavigation system will go into the ARVs as well as the MULE (multipurpose utility) vehicle, a 2-ton robot with a variety of missions, including communications relay, reconnaissance in urban environments, logistics carrier and classified, missions. It also may go into some of the MGVs.
Adams says while most FCS platforms probably will rely on gigabit Ethernet for internal data transfer, a wireless system also will be necessary to enable the crew to retain control of the vehicle even if they leave it. That is expected to tie into a version of the Land Warrior soldier systems suite to enable personnel on foot to stay in communication with their vehicles, exchange data with it including relay on to the battlefield network, and possibly even control some systems.
Diagnostics and prognostics also are being incorporated into FCS — not just for standard maintenance but also to predict failures. In addition, the new vetronics will do more and more of the functionality of the vehicles, providing more information and more decision capabilities. That includes a system-to-system common operating environment (SoSCOE) to drive a lot of commonality of software, including command and control services, maintenance, monitoring, and services for navigation and communications. As a result, the new force will comprise a far more powerful and integrated system than current platforms, with a much heavier reliance on COTS components.
"It is very important for the Army to consider, in its acquisition policies, the use of COTS components," Fulmer says. "By commercial, I don't mean consumer electronics, but commercially available now, rather than custom designing all of the electronics, as was done in the Abrams. For example, displays, computers, and such were custom-fit inside the Abrams. Any upgrade would require special knowledge and engineering to try to retrofit new technologies. When you use COTS, you're using things that are standardized and therefore interfaces are well defined and well known.
"If you want to remove, replace, or update any part of the customized panels and displays and engineering done on the Abrams, you have to go back to the source rather than opening it up to the best of industry to come in and compete. It's very difficult for the government to get the best value when they want to do technology insertion because they went custom rather than COTS at the beginning," Fulmer continues
Even as the 18 planned FCS manned and unmanned vehicles begin to take the field around 2010, such current systems as the Abrams M1A1/2 main battle tank and the Bradley M2A3/M3A3 Fighting Vehicle will continue to play a role in the Army's planned network-centric Objective Force. Given the difficulty in backfitting some components, what influence the FCS technology push will have on them is yet to be determined.
"FCS will push the envelope of performance, which may make them more expensive," Adams warns. "There is some potential for using FCS vetronics for retrofit. However, there are no plans at this time; not many current platforms have upgrade budgets. Some prototype work has been done on the Abrams and Bradley, but no production decisions that I'm aware of, with the exception of the common engine."
Interoperability with joint and allied forces is a primary requirement for all FCS platforms, including the electronically comprehensive, drive-by-wire robots.
"I don't see any common system electronics requirements, but some of the UAVs will be common within the services. I don't know of any program driving commonality with allied systems, although they do have interoperability requirement," Adams says.
"The big hitters are the network technology, robotics, active protection (which drives more comprehensive electronics into the system) and an increasing use of COTS. The trends have been the same for the past 30 years and aren't likely to go away, whether FCS or other efforts."
Where the future ultimately leads for FCS vetronics and a network-centric U.S. military is still evolving and subject to almost continuous change.
"We're in a period of history where we're going through an information revolution, with information and network technology evolving extremely fast," Fulmer says. "We're just learning how to do some of the things we want to do with regard to the network-centric battlefield. It will be critically important for this evolving technology to be refreshed as painlessly as possible in the future."
FCS power design presents unique challenges
Finding power solutions for the electronics-heavy Future Combat System (FCS) offers a mixed bag of requirements and potential solutions.
In some ways, the FCS vehicles will require less power; in others, more. The extensive use of commercial off-the-shelf (COTS) hardware is to help lighten the vehicles, which will average less than one-fourth the weight of an M1 Abrams main battle tank, thus reducing the power required to move the vehicle. On the other hand, the on-board vehicle electronics (vetronics) systems will draw more electric power than ever before.
"We're finding with some of the applications of commercial hardware we can make things lighter, they require less power and thus less cooling and the package size is smaller and they are easier to ruggedize," says Curtis Adams, associate director for vetronics technology at the Army's TACOM RD&E Center (TARDEC) in Warren, Mich. "If you are putting a shock mount onto a line-replaceable unit (LRU), you have to have one that fits the weight of the LRU. We're finding that through technology migration, we can create smaller packages.
"The less power, the less cooling, and less effort on the engine. When looking at an engine power curve, cooling, especially under high load, is a major factor," Adams says. "So the miniaturization can help us get to the weight we need to be at to be successful. Part of the task is what will we have to do (in components) if we transition to a 270-volt or even 500-volt power system. You have to look at it from a system perspective and look at the best way to do that. By going to higher voltage, we feel we can use smaller, more efficient motors. That is a potential way to reduce the overall weight of a given vehicle. Auto manufacturers are looking at the same thing."
Another change is the conversion to electric drives for many platform elements previously relying on hydraulics and, in some cases, for the platform itself.
"All turret systems have been hydraulic in the past, but now are moving to direct-drive pulse width modulated (PWM) DC motors, getting rid of the hydraulic pumps, oil reservoirs, and high temperatures associated with that," explains Doug Patterson, marketing director for Vista Controls Corp. in Santa Clarita, Calif. "A DC motor normally is either on or off, forward or backward. Now they are putting on sophisticated control systems, using feedback from the motor, to drive the motor with essentially an AC-modulated pulse to get very fine speed and position control.
"This has been around for a long time, but some of the drive electronics to control these PWM motors are shrinking," Patterson continues. "It all comes down to the drive transistors. There have been advancements in technology to vastly increase drive currents, break down voltages and reduce turn-on resistance. When you turn a transistor on, the resistance to the DC voltage is getting lower and lower. And wasting a lot less power. That allows the drive electronics to shrink."
Meanwhile, how the platforms themselves will be powered also is changing how FCS systems are likely to be designed.
"The conversion from standard gas- or diesel-powered equipment to all-electric or hybrid electric creates a need for significantly higher levels of electronic power. So the need for efficient power generation and distribution is much more important," says Bryan Rogers, vice president for sales and marketing at International Rectifier Hi-Rel Products Group in Melville, N.Y.
"IR offers products tailored to those applications, such as high-power IGBT (insulated gate bipolar transistor), solid state power controllers to control power distribution throughout the vehicle. We've also developed a line of MIL-STD 1275-compatible DC-DC converters used to power the electronic systems within the vehicles."
MIL-STD-1275 is the military specification governing the interface with the 28-volt power system within military vehicles.
Rogers says the technology enablers in this effort include much more efficient invertors and improved battery technology to supply power to all the vetronics.
"Both commercial computing and communications, as well as commercial and military GPS efforts, are the drivers for these electronic developments. You get a lot more capability at much lower cost, but still have to operate in a very harsh environment, so the designers have to be very careful to make sure the COTS equipment is capable of surviving in a harsh environment," he says. "Full mil-spec, high-end industrial products are available that are protected from harsh environments and high moisture levels. It is really up to the system designer what level of product they feel comfortable with."
The future of such developments may be considered extremely fast in developing by military standards, even if slow by commercial norms.
"Instead of a traditional transmission, with a mechanical drive system, you might have electronic drives, with increasing use of electronic motors and actuators, including electronic motors for each wheel," Rogers predicts. "We are working on a number of programs in early stages of development power semiconductors, DC-DC converters, power hybrids and power modules we're also doing some IRAD tailored to the military electric vehicle market."
Even before FCS is deployed at the end of this decade, new power elements are being brought out for the Stryker interim armored vehicle, which is now heading for its first deployment in Iraq. The primary weapons platform for the Army's new Interim Brigade Combat Teams (IBCTs), the Stryker is a deployable wheeled armored vehicle that combines firepower, battlefield mobility, survivability, and versatility with reduced logistics requirements. It represents the Army's effort to cover the near-term capabilities gap between the relatively old heavy force and the future lighter FCS.
An automated ammunition handling system (AHS) will aid the main Stryker vehicle. The AHS is designed to make the most of technology by incorporating increased computer resources in smaller sizes.
"The AHS system is 6U VME, a series of cards, duplicated in separate enclosures, that deal with the auto loader, replenishment, etc.," Patterson explains. "In the development of the chassis, we went to a new type of hybridized construction to reduce cost and weight."
COTS largely drive the vetronics effort for Stryker and FCS, which reduces development and proof-of-concept costs, although the "COTS" for Stryker comes largely from existing military systems.
"The vetronics systems, then, are still similar between the Abrams and the Stryker vehicle. It's just the mechanics are changing in and around the electronics to catch up. The mechanical systems are being upgraded in technology to more closely match the enhancements and technology insertions afforded by the new vetronics," Patterson says. "I believe a major goal of FCS is to really marry the electronic and mechanical technologies to come up with very utilitarian, light weight and lower cost vehicle systems."