Novel twist on display technologies gives Army generators enhanced capabilities.
Two new types of flat screen displays are now being used in rugged military and commercial applications. The first type, which was designed for use on U.S. Army field generators, is an intelligent display screen that employs an innovative “transflective” design. This allows information to be easily read in both bright sunlight and darkness while requiring unusually low power inputs to operate.
The second type is a series of flat screen video displays that use active matrix liquid crystal display technology. They were designed for applications that require compact size, reduced weight and the ability to withstand harsh environments, including shock, vibration and dust.
The first version will be used on the latest variants of the Canadian light armored vehicle (LAV-25), and several countries participating in the international space station project are purchasing both versions of the display.
The displays are produced by Interstate Electronics Corporation (IEC), Anaheim, California, a wholly owned subsidiary of Scott Technologies Incorporated, Willoughby, Ohio. IEC designs and manufactures a line of flat panel displays based primarily on active matrix liquid crystal display (AMLCD) technology as well as cathode ray tube, electroluminescent and plasma displays for military and commercial applications. These applications include use in night vision systems, forward military command centers, train locomotives, field weather stations and 18-wheeler truck cabs.
IEC, which has been in business for 42 years, also produces instrumentation for fleet ballistic submarines and ground position satellite equipment for training ranges and smart munitions. While historically its business activities have been primarily focused on military markets, the company’s sales of display systems to prime contractors in commercial markets have grown to approximately 60 percent of its business.
The company’s ImpactVision Solar industrial display system (IDS) is a 9.4-inch monochrome triple super twisted nematic (TSTN) system made from commercial off-the-shelf components and packaged in an environmentally sealed box. According to company officials, this is the first time that TSTN technology has been used for a military application.
IDS was designed for the latest versions of the U.S. Army’s tactical quiet generator—the M532 30-kilowatt, 60-hertz generator; the M501 30-kilowatt, 400-hertz generator; the M534 60-kilowatt, 60-hertz generator; and the M531 60-kilowatt, 400-hertz generator. The Army ordered 4,000 of these types of generators from the prime contractor in 1998.
The generators required an inexpensive system that could display critical information in a readily understandable format that was clearly visible in sunlight as well as at night. It also had to survive harsh operating environments and be easily operated, monitored and adjusted by personnel with limited training.
According to Zeev Kalansky, IEC business development director, the prime contractor for the tactical quiet generator approached his company to develop a display that could meet these high standards within very tight budgetary constraints.
“IEC engineers chose to use TSTN technology primarily because of its ability to operate in direct sunlight,” Kalansky explains. Using this technology, they developed a “transflective” display, which reflects sunlight to enhance the brightness and contrast of the liquid crystal display. “The more light, the better the display looks,” Kalansky asserts. At night, the display becomes “transmissive” and transmits the backlight through the screen to illuminate the display. A standard electroluminescent display uses powerful backlights to improve the display’s contrast sufficiently enough to allow it to be read in bright sunlight. This requires greater power, weight and volume, and is consequently more expensive to manufacture and operate.
“TSTN is a relatively new technology,” Kalansky explains. “IEC uses technologies that are developed by other companies. In this case, the TSTN components are manufactured by Sharp. We will adapt and modify them, as we did in this case, to develop new applications. The prime contractor approached us to develop the display.”
The display is protected by a glass window that has been treated to reduce glare. Special coatings are also added to protect the display’s electronics from the effects of high altitude electromagnetic pulse and electromagnetic interference.
IDS has an embedded 50-megahertz 486 processor that interprets all the sensory data and then displays it in an easy-to-understand format. In a cutting-edge use of technology, the processor employs a flash disk to store the Windows operating system and the unit’s software.
The intelligent system allows the computer gauges to have programmable limits that can be set to alert the operator about potential problems before they become critical. Data can be displayed in bar, analog or numeric formats, and the operator can call up multiple screens to show different or additional information.
“IEC engineers designed the IDS graphical screens for the MTV generation, which is comfortable with computers and comfortable with seeing information presented in those formats,” Kalansky says.
Older generators use mechanical gauges and dummy lights to display information about fuel supply, oil pressure, voltage output, current and temperature, and to indicate problems. These are static signals that transmit little or no intelligence or information about the system’s operation or potential problems. In addition, the design of older generators required constant supervision to ensure correct operation, and the multiple cables from the sensors to the gauges increased maintenance costs, company officials explain.
IDS can be operated through a wide range of temperature extremes without losing any displayed data, and it has automatic contrast control to maintain legibility of the data outputs. It can be ready to use within five minutes after it has been cold-soaked to a temperature of -32 degrees centigrade or heated to 50 degrees centigrade. It has a mean time between failures of 25,000 hours, a mean time to repair of less than one-half hour, and a National Electrical Manufacturers Association rating of 4/12 for resistance to harsh conditions. The display complies with Mil-I-45208 and Mil-Q-9858 standards and can operate at an altitude of 15,000 feet and resist up to 2 gs of vibration.
According to Kalansky, the new generators, with their innovative displays, are being procured by a number of foreign countries. Furthermore, although the generator was developed for U.S. Army requirements, “In theory, they could run a chicken farm or a kitchen,” Kalansky says. “IEC is pursuing applications through our prime contractor to market these generators without the military specifications to commercial markets.”
The WarriorVision-10 video flat panel display, which is also produced with commercial off-the-shelf components, uses a 10.4-inch AMLCD system that has 640 pixel x 480 pixel resolution, on-screen text overlay capabilities and a 20,000-hour mean time between failures. It uses a modular design that ensures that future display technology advances can be easily incorporated. For example, the current circuitry would support installation of new AMLCD screens that were brighter or had wider viewer angles.
IEC manufactures the WarriorVision-10 in three versions. The video display version is equipped with a programmable serial port, an RS-170A/CCIR video input port and a buffered video port. The programmable serial port allows a user to transmit serial alphanumeric information to the screen. The RS-170A/CCIR port is a feature that IEC officials claim is unique among flat screen displays on the market, as it is compatible with both national television standards committee video inputs from U.S. cameras as well as phase-alternation line video inputs from European cameras. The buffered video port allows multiple displays to be connected in a daisy chain so the user can switch from one video source to another.
The touch panel version includes an analog video graphics array (VGA), video input and touch panel that allows the user to interface with the computer through the display. It can be used to control equipment through the computer screen instead of with function keys.
GM Diesel Canada selected the WarriorVision-10 for the driver’s display of the infrared system on new LAV-25s and recently issued a second production option to IEC. “The compact size of the display makes it ideal for the confined spaces of armored vehicles like the LAV, and its AMLCD technology provides a very high resolution of the images to the driver that are transmitted by the infrared camera mounted on the front of the vehicle,” Kalansky says.
The video display has been selected by Canada, Germany and Japan to be included in equipment they are producing for the international space station to monitor minute ground agricultural projects. The VGA version was chosen for controlling the space station’s robot arm. “The displays are good enough to go into space without any additional effort on our part,” Kalansky emphasizes.
IEC has also been collaborating with Kollmorgen Corporation’s electro-optical division, Northampton, Massachusetts, in its effort to develop a system called the compact lightweight armored weapon station. This involves installing video cameras on the machine gun carrier that is mounted on top of an up-armored high mobility multipurpose wheeled vehicle (HMMWV). The gunner can sit in the relative comfort and protection of the HMMWV, look for targets, and aim the machine gun by watching the WarriorVision-10 video display screen. The machine gun is operated using a servo system and joystick.
The trucking industry is a primary commercial target of IEC for these displays, according to Kalansky. “We’ve had discussions with several trucking companies that are interested in putting these displays in the truck cabin to provide navigation and communications information and even entertainment videos that current dashboards are unable to provide,” Kalansky says.