Reliability Modeling Of Integrated Modular Avionics System Platform Using AADL,And GSPN Analysis Method

Integrated Modular Avionics(IMA) system is considered as an important development direction for future avionics of large passenger plane and it adopts a resource sharing architecture, which provides more complex and powerful avionics functionality. At the same time, however, it brings about more sophiscated fault proliferation model. Once the shared resources fail, the fuctions hosted on them are faced with the possibility of failure; furthermore, it will lead to the fault propagation and mutual infection. In addition, fault containment and backup mechanism are wildly used in order to improve avionics system's reliability, which makes avionics system show significant dynamic characteristics. Meanwhile, with the continuous increasement of avionics system's scale and complexity, the reliability analysis methods such as directly constructing fault tree by reliability/safety engineer have been unable to satisfy the requirements of Design & Development and Upgrade & Maintenance. Therefore, it is necessary that using the unified model form, establishing an effective transformation rule and combining formalized analysis technology improve the efficiency of reliability/safety analysis in the process of avionics system's design and development. In the situation mentioned above, this paper puts forward a method by using Architecture Analysis &Design Language(AADL) to establish IMA platform reliability model, and then transforming it to GSPN(Generalized stochastic Petri nets) for reliability analysis.Firstly, this paper conducts an investigation into related IMA standard, literature and industrial practice such as Boeing B787 and Airbus A380, which contributes to summarizing components of IMA platform and the relationship between each component. By doing so, we can build a “bridge” between the component of IMA platform and the element of AADL, which makes it possible to use AADL to describe IMA platform architecture. Then, this dissertation has a study of the error behavior of isolated software, hardware and component and a research on the error propagation between hardware and software and the error propagation between components are made in a certain degree. What is more, the corresponding error models established by AADL are also presented. These studies could provide guidance for the establishment of the AADL reliability model of IMA platform.In order to further analyse the dynamic behavior of fault in reliability model established by AADL, this paper also studies the transformation rules from AADL reliability model to GSPN, mainly involving isolated component transformation rule, error propagation transformation rule and mode change transition rule. All these researches on transformation rules lay the foundation for the transformation from AADL reliability model to GSPN model. Finally, this paper takes display function executed on IMA platform as an example to verify the validity of this reliability analysis method and comparative analysis of different configurations for display function is performed as well. The results show that at the cost of permitting, reasonable use of backup and fault containment can effectively enhance the reliability of the IMA.