Posted By John McHale
Military avionics displays take advantage of the latest commercial technology, such as light emitting diode (LED) and active-matrix organic light-emitting diode (AMOLED), yet designers still face challenges integrating the new technology in rugged environments.
Mature technologies such as liquid crystal displays (LCDs) are "very mature and barriers to entry are low -- with lots of new players saturating the market," says Gregory Walters, marketing manager of crew interface products at Honeywell Aerospace in Phoenix. "However, technological differentiators still exist in LED backlighting; lower cost, lower power consumption, higher reliability (almost 10 times), redundancy: no single bulb failure can shutdown the backlight.
"Sequential backlighting is next on the horizon -- only illuminating those LEDs that you need -- providing even lower power," Walters adds.
Another trend among military avionics displays "is the use of large area displays with night vision imaging system (NVIS) touch screens in fighter cockpits," says Tim Cantrell, vice president of Avionics North America at Barco in Rancho Cordova, Calif. "We offer the only NVIS compliant infrared touch screen. The IR technology does not degrade the optical performance of the display as do some other touch screen technologies."
"AMOLED is the disruptive technology -- low volume, low power, no backlight needed, flexible for conformal display surfaces," Walters says. "However, it is still three to five years before they are rugged enough for military applications. Also nothing very large has been fielded yet (4 or 5 inches is the current size with nothing close to 15 inches yet)."
The primary application for AMOLED technology is cell phone usage right now, Walters adds.
In the meantime Walters says avionics integrators want high luminance (brightness); no reflective glare especially for bubble canopies; low power consumption; high reliability; reduced line replaceable unit (LRU) size to make a flat panel display actually flat; obsolescence mitigation; plug and play integration; intuitive information displayed for reduced pilot workload; significant data processing; and sharing so operators can know where the bad guys are; and touch screen drag and zoom capability with gloves on.
All the new technology is exciting but ruggedization headaches remain.
"It is more difficult to harden a display today because of the shrinking avionics and defense market in relation to the civilian market," says Jim Zentner, manager of business development at Astronautics Corporation of America in Milwaukee. "Military hardware does not drive innovation as much as the commercial realm and does not dictate the environmental or electromagnetic interference (EMI) requirements that today's electronic components are built to. Getting components that can be used in these applications is becoming more of a challenge as the iPod world takes over."
Astronautics latest display is a civil and military certified 6-by-8-inch multi-function color display (MFCD) called the Astronautics Smart Display, Zentner says. It uses LED NVIS compliant backlight, accepts video inputs (via RS-170), and has a 1.3 GHz Intel Atom processor with aircraft interfaces and bezels available. It is also certified to the DO-160F standard for civil avionics certification, he adds. The device is used in U.S. Force C-130 aircraft.
An example of when older displays cannot meet current requirements is the E-scope Radar Repeater Display (ESRRD), which is used in the Tornado aircraft, says Eyton Zelazo, business development manager for Astronautics. The display uses forward looking radar which provides the pilots with terrain on low level flights, he says.
"The Current E-Scope Radar Repeater Display (ESRRD) is a form fit function drop in replacement for the CRT based unit which was provided by Astronautics for the Tornado aircraft over 30 years ago," he continues. The new unit uses Active Matrix Liquid Crystal Display (AMLCD) and a proprietary designed full color RGB backlight to provide a high brightness ruggedized display head that is also NVIS compatible, he adds.
Zelazo says the main technological advances of this instrument over the previous monochrome technology are: digitally controllable emulation of the phosphor decay in the original Direct View Storage Tube (DVST); a function to highlight flight path incursions in bright red to alert pilots of possible collisions; graphics overlay of symbols and markers on full color high resolution video; lower power; lower cost; increased reliability; and it is half the weight of the original.
"Adapting the ever growing industrial and commercial electronics for use in military and other applications where hardening is required is getting more and more difficult, yet the end user for avionics, both military and commercial, are still requiring the end product to meet performance requirements in the extreme environment," Zelazo continues. "Getting components that can be used in these applications is becoming more difficult. The ESRRD instrument uses the highest grade components available to meet the requirements of the customers."
The rugged mil-spec monitor (MSM) series from Digital Systems Engineering (DSE) are on such Air Force programs as B-52 bomber. The display is designed to operate under the extreme environments found in high performance jet aircraft, off-road, and tracked vehicles, unmanned aerial vehicle (UAV) applications, marine, and submarine vessels. DSE's displays are housed in an IP67/NEMA 6P sealed, milled billet aluminum enclosure. It is light weight and watertight, with sealed, military-grade connectors.
Boeing officials selected the DuraVIS 3006 and DuraVIS 4300 from Parvus in Salt Lake City to serve as the flight test display (FTD) and the instrumentation crew station control panel (ICCP) respectively for the P-8A Poseidon maritime patrol aircraft.
The display system is a combination of the Parvus DuraCOR mission computer with a commercial-off-the-shelf (COTS) multi-function display. The system will present flight, sensor, mapping, advisory, and other information for the P-8A. Qualified to MIL-STD-810F, MIL-STD-704E and MIL-STD-461E standards, the DuraVIS 4300 offers low-temperature operation (-20 degrees Celsius) and resistance to shock and vibration profiles that will be experienced by the P-8A.
Applied Display Technology
Simi Valley, Calif.,
Astronautics Corporation of America
Rancho Cordova, Calif.
Digital Systems Engineering
Newbury Park, Calif.
Esterline CMC Electronics
Ville Saint-Laurent, Quebec
Flight Display Systems
Innovative Solutions & Support (IS&S)
Interface Displays & Controls
Cedar Rapids, Iowa
Salt Lake City
Grand Prairie, Texas