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Moving Us Closer to the Holy Grail
Written by Tom Marlowe
MT2 2009 Volume: 14 Issue: 6 (November/December)
Rapid Advancements in Visual Systems'
Hardware and Software Must Still Be Aligned
to Training Tasks and Requirements.
And with recent advancements in commercial off-the-shelf technology (COTS) for visual display systems, warfighters receive more realistic training in immersive environments than ever before.
These advancements have proved useful, for example, to NAWCTSD in Orlando, which is responsible for training Navy personnel in preparation for aviation, surface, subsurface, and ground operations. Still, the U.S. Navy has been striving to make its systems even better, Ron Wolff, NAWCTSD chief engineer for Visual and Sensor Simulation, told MT2.
“We have seen a significant increase in the overall visual display system capabilities in terms of rendering real-time textured pixels, but we are still struggling with displaying high quality pixels to the screen as seen by the observer,” Wolff stated.
“Especially challenging to the visual display community are collimated cross cockpit wide field of view displays. Ultimately, the effective resolution of the visual display system is limited not by the pixel count of the image generator or projector but rather the limited luminance and contrast as well as the effects of geometry distortion and blurring for fast moving objects,” he added.
Many image generators run from personal computers these days, and image generator technology has benefited as PCs have gained much more processing power and memory in recent years, Wolff said. Improvements in the graphics processing units (GPUs), increases in memory, and the introduction of a programmable graphics pipeline architecture have boosted military training capabilities tremendously.
Projectors, too, have seen rapid advancements as the marketplace has moved away from analog-based CRT projectors to digital projection technology, Wolff remarked. Digital projection technologies may use digital light processing (DLP) or liquid crystal on silicon (LCoS) display screens with arc lamp light. Traditionally, digital projectors have suffered from limited lamp life, which costs more money because training commands must replace them frequently. However, that has been changing, Wolff revealed.
Finally, hardware and software advancements have made it much easier to correct distortions and blend edges automatically when using multiple projectors to create a big picture for training scenarios on non-linear surfaces, such as domes. These hardware and software improvements reside directly inside an image generator or projector, eliminating some of the traditional headaches for training providers, Wolff said.
“All of these advancements have led to lower cost and higher fidelity visual display systems with less down time for repair, alignment and maintenance,” he declared.
While the commercial marketplace has driven many of these improvements, Wolff still would like to see some advancements in specialized training and simulation applications.
“We continue to struggle with standardized methods of developing rapid, low-cost, high-fidelity databases that are well correlated and readily reused from one application to the next,” Wolff lamented. “This becomes especially more complex and demanding as we move toward the requirement and need for fully correlated databases, including the simulation of physics-based sensor simulation.”
Wolff also cautioned that training providers also must plan to use display technology effectively by making certain that training scenarios are meeting the needs of the warfighter.
“We are seeing tremendous advances in visual display system technologies, but we need to be cognizant of the real training requirements so that we define performance requirements that ultimately lead to cost-effective training solutions that can be tied directly back to the training tasks,” he said.
MORE CAPABILITIES, LESS COSTS
One of the leading manufacturers of visual display systems for military uses is Christie Digital Systems USA Inc., which has combined its own technical expertise with commercial advancements to bring the best possible solutions to military training needs.
Christie Digital combines best of breed technologies with the company’s capabilities to address training needs and its systems engineering expertise to produce complete solutions for training challenges, Dave Kanahele, Christie’s director of Simulation Solution Management, told MT2.
Due to commercial innovations, image generators have dropped in cost to tens of thousands of dollars per channel, while improvements in shaders and filters have provided additional capabilities, Kanahele said.
These decreases in costs along with increases in capability have made it very attractive for military training commands to invest in arrays of projectors capable of providing a very detailed training scenario, Kanahele noted, but large numbers of projectors still present challenges where the cost of ownership is concerned.
“As the number of projectors increases, the mean time between failures for the system also increases. So the question becomes how do we scale to these very large levels to achieve these high resolutions and still have a system that is supportable and maintainable at a reasonable cost over the lifetime of a simulator, which can be 10-15 years or more?” Kanahele reflected.
Christie Digital has addressed many of the challenges of maintaining projectors with its Matrix line, most recently introducing the Christie StIM projector, which uses the company’s Twist solution.
The Christie Matrix line has hardware and software built into the projector to map pixels in a non-linear format to offset any distortion as a result of projector geometry. It also offers Accuframe, for maximizing dynamic resolution while minimizing smearing, and autocalibration, for setting geometry and blending automatically.
In addition, Christie’s Mirage line of projectors provide 3-D stereoscopic capabilities that have proved useful to clients such as the Air National Guard, which uses the 3-D stereoscopic capabilities in a training program for its boom operators.
But Christie StIM is the first solution to meet some demands from warfighters to make training more realistic in some instances of flight training. Christie put its systems engineering expertise to work with its proprietary knowledge and commercial advancements to overcome some of these challenges to make training more realistic.
“Those are the scenarios that our customers are coming to us with and telling us we really don’t have the capabilities that we would like to have there. There have been ways that industry has attacked those that address a subset of the requirements but not a complete solution that integrates the full spectrum of requirements, and certainly not with low risk, commodity technologies,” Kanahele stated.
For example, pilots historically have trained with systems that offer night vision simulation, where they wear helmets and see images depicting how their night vision goggles would represent a scene. The helmet would be tethered to a computer that would feed the images to the trainee.
Pilots complained that the training wasn’t realistic, so Christie and other companies have tackled the problem to develop night vision stimulation. Stimulation permits pilots to wear their own night vision goggles into a training scenario because advancements in technology provide enough light for those goggles to actually work on their own within a training environment.
Christie Digital introduced night vision stimulation for its A-10 training program, delivering more than 100 channels for that program to date, Kanahele reported.
“The problem with the stimulation approach is that it’s difficult to get the right balance between infrared energy that stimulates the goggles and the amount of visible energy you see when you take the goggles off,” Kanahele said. “The ratio between that energy has been fixed traditionally because it’s an optical solution.”
The Christie Matrix StIM tackled that problem by introducing InfraRGB, a four-part LED light source that provides red, green, blue and infrared light.
EVOLVING REQUIREMENTS
L-3 Communications’ Link Simulation and Training won the contract in January to provide a mission training center for the F-16. That contract requires that L-3 provide a training system that offers 20/40 visual acuity with the ability to upgrade to 20/20 in the future, said Frank Delisle, Link vice president.
“The typical visual acuity is 20/100 or 20/80 in systems deployed in recent years,” Delisle told MT2. “Now with the latest requirements, given the advent of the digital LCoS projectors and more capability, we have moved down to 20/40, and we are moving toward 20/20 visual acuity. The technology trend is moving us closer to the Holy Grail, which has always been 20/20 like in the real world and the comparable level of brightness and contrast.”
Currently, 20/40 visual acuity represents the state of the art for display capability, but 20/20 will become affordable within the next several years, Delisle said.
But as advancements bring higher and higher resolution into military training scenarios, military trainers must ensure they have the content to put into those scenarios in order to take full advantage of those capabilities, Delisle warned.
“Say at home you bought your HDTV, which is great because you have terrific resolution. But if you don’t buy HD channels to provide HD content, it’s still going to look terrible when you put the regular channel on there because you don’t have content that matches the resolution,” Delisle observed.
“Display systems with more capability create a companion problem because you have to take content that you have been using and turn it into high-definition content,” he said. Creating the content at high resolution and rendering it in real-time requires terabytes upon terabytes of information. As such, the computational engine that drives the display system has increased in capacity about eight times what it used to be to produce the same result, Delisle said.
The picture content itself has literally quadrupled to meet the need of high resolution content but fortunately CPU and memory capabilities have increased in capability while falling in price.
To provide immersive displays that make the best use of high-end technology while providing matching content, L-3 introduced its HD World integrated product suite to fulfill military training needs, which have been rapidly involving.
Take basic training scenarios, for example. Delisle pointed out that most training scenarios for today’s warfighter involve busy urban settings where people and infrastructure could interfere with the military mission.
“The conflicts of today are not the old conflicts of traditional military adversaries flying off in high skies or well-defined military areas. Everything now has the mission perspective of a civilian urban environment,” Delisle commented. “To create a relevant scenario that has meaning, you need to have thousands of people and cars and all of this dynamic activity in the city to provide the mission scenario and training relevancy.”
So the F-16 training scenario might involve the pilot in the urban setting but also interacting with a forward observer on the ground who is helping to target the pilot’s munitions in addition to an unmanned aerial vehicle that is feeding information to the pilot.
PROGRAMMING THE PIPELINE
Rockwell Collins is producing the F-35 Joint Strike Fighter display system for pilot training. In so doing, it is putting its engineering expertise to work in creating one of the most adaptable training simulators ever developed.
“Our strategy is to provide the right performance solution for the budget and the training application that is involved. We tailor our display product in the same fashion. We have high-end display solutions for advanced applications where we would use our QXGA3, million-pixel 2015 projector on the Joint Strike Fighter program or the Galileo program,” Nick Gibbs, senior director of Simulation and Training Solutions at Rockwell Collins Visual Systems, told MT2.
“There are lesser applications where we would use a lower cost and lower resolution projector,” he added.
Rockwell Collins has built upon its experiences of producing training for E-2D aircraft for the U.S. Navy, Black Hawk helicopters for the U.S. Army, and 737s for commercial airlines. It built its Simulation and Training Solutions company by combining two companies it acquired in recent years—Evans & Sutherland and SEOS Ltd.
After acquiring the resources to do so, Rockwell Collins introduced its own line of image generators to maximize flexibility and performance. For ground vehicle applications, the company offers its EPX-50 family of products, which are PC-based image generators. As military needs scale up, they turn to multiple PC boxes for the EPX-500, which would be used for more sophisticated applications like the Joint Strike Fighter where there is a need for more performance capability and faster update rates. Beyond that, Rockwell Collins can scale up to its highest end products—the EP-1000 for the commercial market and the EPX-5000 for the military market.
Meanwhile, Rockwell Collins turns to COTS projectors from companies like JVC or Christie Digital to complete its systems, Dennis Hartley, Simulation and Training Solutions principal engineering manager, told MT2.
“There are COTS projectors out there with high resolution like LCoS. They are the highest-resolution projectors out there. They go up to just under 10 million pixels,” Hartley described.
“DLP is advancing tremendously too. They have in the past been at the maximum HD resolution, which is 1920 x 1080. But they are coming out with new products that are pushing the resolution as well. They are going all the way up to 14 million pixels in the next year or two. DLP projectors, however, do not have quite the dynamic range so they are not as suitable for stimulation applications for night vision goggles. But they are good projectors and they are cost effective,” he added.
As training systems have been moving toward LED displays that use arc lamps instead of old CRT technology, LED lamp life has been increasing, Hartley noted. LED lamps could now last 20,000 or even 50,000 hours.
Moreover, other advancements are offering military training commands the ability to change the training scenarios as they are occurring.
SPGA technology has improved significantly such that Hartley believes companies can build systems using SPGA technology only, which would result in a fully programmable rendering pipeline.
Even if that were not the case, Intel and AMD have introduced platforms that permit the use of CPUs and GPUs to create a programmable pipeline as well, Hartley noted. The Intel Larabee platform and the AMD Fusion platform, in addition to SPGA rendering, will explode in the next three to five years, Hartley predicted. ♦