With new projection technologies entering the entertainment, scientific and home theater markets, Chuck Weirauch spoke with leaders in the civil aviation simulation industry to gain their perspective on how, when, and if such technologies might become available in this market in the near future.
The goal of eye-limiting resolution has long been the Holy Grail for those in the flight simulator business, and now that goal seems achievable with the 4K projectors coming to commercial market. But whether the advantage of a resolution of four times that of conventional HD (3840 x 2160 pixels) will provide enough benefits over cost considerations is open to debate.
According to Dan Myers, marketing director for FlightSafety International's Visual Simulation Systems, his company is seeing that now for the most part 4K projectors are being put on contract to replace older technology.
"4K allows us to reduce the projector count and therefore the IG channel count," Myers said. "This makes it less expensive than the current technology, but with higher quality and pixel count. Customers are using this technology to actually reduce the cost by fewer projectors and fewer channel counts. We can also use this 4K technology for eye-limiting resolution requirements. However, we see that as very few and far between, at least for the time being, since that still requires an enormous amount of channel and projector count. We do see it in the future, but probably not for a few years because of the acquisition cost."
But rather than moving towards higher resolution projectors, those that are capable of providing a higher frame rate may be more of a near-term solution, Myers pointed out. Going from a 60 Hertz frame rate to a 120 Hertz frame rate sharpens the image immediately. So one trend that could emerge is 120 Hertz projectors being used to provide much higher dynamic resolution as an alternative to 4K, he said.
Graham Watson, Visual Product manager for L-3 UK's Civil Simulation Product Group, said that although it may be that 4K could become affordable, at this stage his company believes that it is not necessary for what is needed as far as regulatory requirements are concerned. Alternatively, L-3 is offering HD resolution on each image generator channel, along with offering as an option a WQXGA format, 4 million pixel projector.
"With this solution, we can see some real advantages, such as runway recognition at range, better light point fidelity and the legibility of sign boards," Watson said. "So 4K will come with the march of projector technology, but we are already seeing the benefits of improved resolution, and indeed a larger field of view."
Graham Olive, Technical Lead in the L-3 Product Authority Group, explained just how his division is working on expanding fields of view for full- light simulators for newer aircraft. "Along with the various aircraft types, we are working with the new Airbus A350 simulators with very large and curved cockpit windows, so we are putting an effort in trying to fill the field of view from those windows to get rid of some of the artifacts and even the glazing.”
"So rather than going to ultra-high resolutions, we are going to optimize filling the field of view beyond what the regulations require."
Dennis Hartley, Chief Systems Engineer for Visual Systems for Rockwell Collins Simulation, Visualization and Training Systems (SVTS) said that his company has provided simulators equipped with 4K projectors to the US Air Force for air refueling training and for a Mitsubishi Regional Jet full flight simulator. However, he does not foresee their use for commercial aircraft training in the near future, since there are no FAA requirements for them.
Laser projectors are now lighting up cinema screens, but it will still be some time before they are employed for flight simulators. FSI's Myers considers laser projectors as "that fruit on the tree" that still can't be acquired just yet for simulation but holds promise for the future.”
"It's still expensive, and I think that there are still some safety concerns," Myers said. “But certainly lasers would provide us with the kind of contrast that we so desire, and for many applications, especially on the military side. So the laser has the promise of much better contrast, a larger field of view capability and increased resolution potential. But this will come down to cost and life cycle cost once the technology is available".
Both L-3's Watson and Olive had worked together to develop a laser light point projector, but that effort proved to be "not right for the market" when LCoS technology emerged.
"Certainly we are aware that there are laser light technologies being used," Sanjay Kale, L-3's Authority Group Manager said. "But the main problem with lasers is speckle, and it is a desperately difficult thing to overcome sufficiently."
Kale said that his company has not developed any 3D stereoscopic maintenance trainers, but it is something that they are "keeping a close eye on".
"At this point, it might not be quite good enough for training," Kale conjectured. "And we are not sure if it can be used over an extended period of time because of possible eyestrain."
Hartley, however, pointed out that there very well could be a future beyond maintenance training applications in civil aviation for 3D stereoscopic projection. He bases his opinion on the fact that by next year nearly all projectors will be 3D capable. When employing these newer projectors in a simulator, all that would be needed to provide that capability would be to add an additional channel out of the image generator. Then training providers would have 3D with a collimated display, he summed up.
"We have had some interest from a customer who sees advantages in using 3D for improving docking training when aircraft are pulling up to the gate and for other ground maneuvers," Hartley said. "You could just turn on the 3D capability when you are training ground maneuvers. There is also potential in helicopter training, but the question is whether you can get pilots to use 3D glasses."
Solid State Illumination
According to Bruno Cacciola, CAE's Director of Product Strategy and Marketing, the company will soon be offering a 4.1 megapixel LED projector, the projectiondesign FL 35, to its customers as an option for its lineup of full flight simulators. The offering will be made in conjunction with the recent release of CAE's advanced Tropos XR image generation system.
"The goal was to provide a higher resolution product in order to leverage commercial off-the-shelf products and offer more capability than we have been able to offer in the past," Cacciola said. "LED also brings advantages beyond just resolution. LED provides better life cycle costs as far as the total cost of the acquisition. This light source is more stable than what we have had in the past, with some of the LCoS applications in terms of less shift in color and brightness, and it also reduces maintenance costs."
John Hester, General Manager of FSI Visual Simulation Systems, feels that the next step in projection technology is in the realm of the LED diode, where the light source has a much greater life than the lamp technologies that are used today.
L-3's Kale said that the company is "acutely aware" that customers are concerned about the lifecycle costs of LCoS projectors. That is why the firm is offering LED projectors when customers request them. In fact, LED projectors are currently being used in L3 civil aviation training centers, he pointed out.
"LED illuminators definitely have a part to play," Kale emphasized. "There may be a window where LED is an extremely good alternative to LCoS before there is one with a laser diode or some sort of solid-state laser illumination comes along."
Hartley said that he is looking forward to laser-illuminated projectors, because they are brighter and have contrast ratios in the same range as what LCoS projectors currently provide. But rather than a laser-only projector, he speculated that hybrid projectors that incorporate laser diodes will reach the simulation market sooner.
"I think that you are going to see a lot of DLP manufacturers come up with laser-phosphor projectors to get higher brightness with a solid-state light source," Hartley said. "There is also going to be laser-illuminated LCoS technology as well within the next couple of years. These projectors will offer better brightness and a better color gamut with a solid-state light source for a better life cycle cost. Overall, I think that that solid state is going to become the dominant thing, and will replace lamp technology."
According to Bob Brantley, manager of Image Generation and Content Products at Rockwell Collins SVTS, in the next two to three years providers of image generators could find themselves facing "a major disruption in the market" for the advanced off-the shelf PC graphics cards that have revolutionized the quality and cost-effectiveness of current simulator visual systems. This disruption, which would be fueled by the transition from central processing unit (CPU) and graphics processing unit (GPU) technology, to that of the next-generation accelerated processing unit (APU) technology by card manufacturers, could make standard PC graphics cards that already are a part of IG systems, more expensive or more difficult to obtain, he explained.
To offset this challenge, Rockwell has begun research on the early generation of APU technology, which Brantley said is currently "not ready for prime time in a realistic multi-channel simulation environment." But since APUs will offer significant advantages of requiring less power, a much faster data transfer rate transfer and fewer components with less cost, Rockwell intends to have a product with this capability ready for the civil aviation market when the predicted disruption hits.
One of the most significant advantages in employing the latest in commercial graphics cards and ever more powerful PC technology for image generators, is more realistic weather replication. But while significant advances have been made in this area, still much needs to be done to simulate actual atmospheric conditions. Hester said that the biggest computational challenge is that of simulating weather on a large scale.
"This is really the grandest computational challenge out there," Hester emphasized. "We have just come out with a product that provides real-time dynamic shadowing and will be providing volumetric cloud simulation in the very near future. The goal is physics-based rendering, which is where we are going to see the most benefit to the training experience, because it is going to add yet another whole dimension to what we already have."
Brantley pointed out that Rockwell Collins already has a physics-based regional weather model available to customers. He added that his company is also looking at ways to tie in live weather streams to that model as well as linking in radar solutions into its image generators.
In addition to more realistic dynamic weather representation, L3's Olive pointed out that what customers are looking for is a much livelier airport scene with dynamic and static clutter to provide more realistic taxi training. Kale said that the company is looking toward adding airfield scenarios that are driven by some kind of artificial intelligence.