Quad-redundant avionics application

Citation

(1999), "Quad-redundant avionics application", Aircraft Engineering and Aerospace Technology, Vol. 71 No. 6. https://doi.org/10.1108/aeat.1999.12771fab.010

Quad-redundant avionics application

Keywords ISI, NASA, Boeing, Software, Flight controls, Avionics

Integrated Systems Inc., (ISI) (Nasdaq: INTS), a worldwide provider of embedded systems software for a broad range of industries, reports that NASA and Boeing have used the MATRIXX toolset to design and automatically generate code for the F-15 ACTIVE "quad-redundant" flight control software, a safety critical application (Plate 4). The F-15 ACTIVE is a manned aircraft and is presently undergoing rigorous flight tests at NASA's Dryden Flight Research Center at Edwards Air Force Base, California. F-15 ACTIVE Control LAWS (CLAWS) are sophisticated safety critical software programs that control the aircraft during flight and prevent it from exceeding the flight envelope. Because they contain thousands of lines of computer code, CLAWS have traditionally been very time consuming and costly to produce.

Plate 4 NASA/Dryden and Boeing use code automatically generated by MATRIXX from ISI in world first quad-redundant avionics application

The MATRIXX toolset is said to have provided Boeing Phantom Works engineers with a robust, high-fidelity means of designing the flight control laws. Verification and validation tests were accomplished at four levels of integration, ranging from interactive simulation at the software unit level in the MATRIXX environment, to piloted Hardware-In-The-Loop simulations that exercised the actual flight software running on the quad-redundant avionics processor.

The final avionics flight software was 98 per cent generated with AutoCode and linked to assembly-level driver code. According to Phantom Works program manager Paul Doane, "MATRIXX not only greatly improved the design of ACTIVE CLAWS, it also generated more than 10,000 lines of code without a single error, saving a lot of time and money in production. The elimination of human errors associated with manual software coding greatly reduced the time and cost of checking and debugging our code".

When the F-15 ACTIVE first took to the air in flight tests at NASA/Dryden, all four NASA-flight test pilots that evaluated the aeroplane were reported to be delighted with its performance and its superior handling qualities. In fact, all four are said to have awarded ACTIVE with Cooper-Harper ratings of "1" (best possible on a scale of 1-10). According to NASA flight test engineers, "There are very experienced handling qualities engineers at NASA Dryden that have never heard of a Cooper-Harper rating of 1 being awarded. These types of ratings are very rare, especially for the first flight tests". During testing, the MATRIXX design automation tool accelerated the design cycle time by allowing engineers to modify the flight code within a few hours of pilot suggestions.

"MATRIXX AutoCode was put to the test by Phantom Works engineers", says Scot Morrison, vice president of Design Automation Solution at ISI. "The success of the F-15 ACTIVE program proves that MATRIXX is highly reliable for safety critical applications, as well as pivotal in saving time and money in development".

Flight testing of the F-15 ACTIVE continues at NASA/Dryden where additional "intelligent" flight control laws are being tested, achieving new standards in avionics software robustness, automation of the software design/development process, and fighter aircraft handling qualities. Using MATRIXX and Phantom Works engineers' expertise, the F-15 Eagle now has new control laws that make it one of the world's most advanced aircraft.

The MATRIXX family of control system design tools is believed to be the first fully automated system that allows for the graphical design, simulation, automatic code and document generation and testing of real-time control systems. For more than 15 years, the MATRIXX family has provided value to numerous embedded control systems engineering programs world-wide. Users include the top aerospace and automotive companies and suppliers world-wide. The MATRIXX product family features SystemBuild, XMath, AutoCode, Document It and RealSim.

Details available from Integrated Systems Inc. Ltd. Tel: +44 (0) 1462 687300; Fax: +44 (0) 1462 687301; E-mail: abennett@isi.com