Military Computers embedded

fighters,

The know of a company that just completed a contract in which the existing USAF fleet of C-5 aircraft had their MADARS system (Malfunction Detection Analysis and Recording System) upgraded with a PC104-based system running VxWorks as the RTOS and software applications designed in-house. I think around 90 aircraft were updated (out of a fleet of around 130 aircraft).

fighters,

Very few, if any Commercial Off The Shelf (COTS) equipment will meet MIL-spec for such things as temperature range, vibration, and shock. Few exceptions exist for equipment used within the confines of manned spaces such as exist on AWACS and some large, special purpose converted transport planes. Consider that in an compartment of a jet fighter at 40-80,000' altitude that isn't climate controlled the temperature can drop below -40degC/F and continuous vibrations of several g's can exist for sustained periods of time. I have worked with several modern radar systems and can assure you that whatever components are used, the interconnects are most definitely not PC104. They are typically very dense, very tight fitting connectors with mechanical components added to prevent separation of boards and backplanes.

Many older systems use proprietary software. Some modern stuff uses things like VxWorks and RealTime-Linux, though special purpose systems still abound. Just about every "black box" [most are typically grey not black] has several "computers" each with a single purpose. More hardware is still cheaper to debug than multi-tasking software.

Norm

many use QNX

fighters,

At those altitudes the air density is quite low, so I would be more concerned about the generated heat, since the convection or even forced air cooling is not going to remove the heat from the components very effectively.

Paul

Check out Military and Aerospace magazine... lots of airborne computer hw and sw ads lots of conduction cooled VME boards in ARINC boxes running Green Hills ADA and Integrity RTOS

Even nominally benign environments aren't that benign if it's a mobile (land, air, sea) application. Low intensity vibrations can lead to eventual failures.

Like embedded applications elsewhere, military embedded apps cover a broad range of complexity. Many are little more than elimination of electromechanical devices that could perform the same function. Some are excedingly complex such as the processing done in radars. All tend to be very special- purpose and there's little in the way of COTS program products that are applicable.

No PC104, it can't handle the environment (-55 deg C high vibration) or the size and power constraints, or the crazy power thats available on an aircraft (alternators) Custom operating systems and custom hardware are standard issue.

Another problem with COTS, usually overlooked by government program managers, is the problem of obscelescence that arises with COTS. When a custom system is designed for the military (not using COTS), the government usually retains all of the design information including engineering drawings and source code. In a pinch (or the next World War) the government could build copies of the system.

With COTS-based design, the government usually doesn't retain any design information, therefore when the time comes to reproduce the system (usually years later), the company that produced the original COTS has gone out of business or the hardware/software has been discontinued. The result is that an entirely new design must be generated, along with all of the development and testing.

Not very realistic to assume that this would work these days, since it would require recreating the whole infrastructure that was once used to create the original product.

Assuming some old product used custom made RTL, DTL or TTL chips and the masks for 2" wafers are stored in a safe place. To start producing these chips again, you first should build the infrastructure to make blank 2" wafers and then the facilities to apply the masks to it in some ancient manner. You would also have to train people to bond the chips in the original approved method to maintain the reliability etc.

In industrial systems, it is common that the customer requires at least 10 years of support for the system. In some situations, it may be feasible to store some critical components for a decade or two, but of course the capital costs are quite high. As long as the interfaces are compatible, it makes sense to make new subsystems after a few years with current technology and swap an old malfunctioning unit with the current version. This way you will not end up with a stock of completely outdated systems or components when the contract period ends.

The important thing is to maintain the interfaces (instruction sets, protocol frame structures, signal levels, connectors, fixing holes etc.) for a very long time, not to recreate some historical relics from the beginning.

What is inside the black block is not important, it could be implemented using COTS technology, even if the original system used some custom made subsystems, in order to achieve the required performance in the old days. When implementing the same subsystem later on, the original performance can often reached with COTS systems.

If some old military system used a card full of TTL chips to implement a multiplier, the same could be implemented with a COTS micro controller (assuming temperature and radiation requirements would not be a problem) with plenty of I/O pins. The _only_ thing the micro controller would do to read the multiplier and multiplicand from input pins, perform the multiplication and write the product to the output pins. Of course, the modernisation and testing of this module would have to be done at a scheduled time (e.g. every 5 or 10 years), thus hopefully before any large scale production is needed.

Paul

Simon,

Caterpillar sells a product called the "Navigator Rugged PC" that is used at mine sites.

See their product catalog at:

See page 13. According the the catalog it uses an Intel 166 MHz processor with Windows NT or CE.

Here is a quote from their catalog:

"The Navigator 10.4cTS is a compact, embedded Intel® PentiumT based hardened PC designed for use in rugged outdoor environments. The system incorporates a 10.4? transflective LCD for superior viewing in high light conditions with a broad-range dimmable back-light for viewing in low light conditions. The integrated high-light rejection infrared touch-screen provides a means for reliable operator input in extreme operating conditions."

Hope this helps

Jim

fighters,