Symbolic algebraic discrete systems theory-applied to a fighter aircraft

Symbolic algebraic modeling and analysis techniques for DEDS are applied to the landing gear subsystem in the new Swedish fighter aircraft, SAS 39 Gripen. The authors' methods are based on polynomials over finite fields. Polynomials are used to represent the basic dynamic equations for the processes (controller and plant) as well as static properties of these. Temporal algebra (or temporal logic) is used to represent specifications of system behavior. The authors use this approach to model the landing gear controller from the complete implementation in Pascal. The authors also provide temporal algebra interpretations of the specifications made available to them. Finally the authors perform a number of symbolic analyses on the complete process (controller and plant). This project is a first demonstration of possible uses of these methods and tools and it shows that these methods and tools scale to a problem of a non-trivial size, i.e. of the size found in complex system designs such as the JAS 39.