Symbolic Algebraic Discrete Systems -applied to the Jas 39 Fighter Aircraft, Part Ii

Symbolic algebraic analysis techniques are applied to the landing gear subsystem in the new Swedish ghter aircraft, JAS 39 Gripen. Our methods are based on polyno-mials over nite elds (with Boolean algebra and propositional logic as special cases). 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 speciications of system behavior. These speciications are veriied both on a model of the landing gear controller, and a model of the closed loop behavior of the landing gear controller connected to a plant. The model of the landing gear controller is made from the actual implementation in Pascal. The tools used are developed by the authors in Mathematica and uses an eecient implementation of binary decision diagrams (BDDs). This project demonstrates possible use and feasibility of these methods and tools on a complex industrial process (the landing control sub system on a ghter). It also highlights some of the user aspects involved in working with this methodology, both computational and principal.