Flexible platform approach for fly-by-wire systems

The development of highly fault tolerant fly-by-wire systems for FAR25/CS25 aircraft is an extensive and inherently complex task. This paper presents the Flexible Platform approach which aims on reducing the development effort of fly-by-wire systems and hence allowing more cost-effective realizations - with a potential even for FAR23/CS23 aircraft. The main features of the Flexible Platform approach are: 1) The software architecture provides a clear separation of system management (i.e. platform management) and applications (e.g. flight control laws). 2) With respect to the applications, the platform management provides transparency of distribution, redundancy and fault tolerance for the complete system, i.e. including sensors and actuators 3) The platform management is composed of a generic middleware and model-based upper management layers, both offering a high degree of specialization capability. As a consequence, the management functionality of any fly-by-wire system can be developed essentially by specialization of the platform management. 4) With respect to quantity and complexity, specialization of the platform management is a challenging task and requires tool-based support. Based on manually defined input data at system level (i.e. without explicit reference to the software), a tool-suite uses modeled system- and software-domain knowledge to generate the major part of the specialization data in an automatic three step refinement process. The paper presents the Flexible Platform in general, but with emphasis on the specialization topic and the specialization tool-suite.