Title : Distributing realtime systems with predominant control

Abstract :

In this thesis, we propose a more reasonable design method about automated production systems (APS). We concentre our efforts about APS who exhibit hard real-time constraints and predominant control. Our approach is based on synchronous models: strong synchonous model `a la ESTEREL and weak synchronous model (one delay of communication). This duality strong synchronous/weak synchronous is closely connected to geographic locality (locals and remote communications). These models garantuee both a deterministic behaviour logical and temporal. Our approach trivially introduces a bias in the distributed behaviour with respect to centralized implementation. However, in specific cases, we point out the bias is insignifiant. Our approach also allows the validation a priori of temporal constraints since she's based on a synchronized clock (global time). The constraints's verification uses `observateurs' technic, which are composed with a model of the distributed APS by strong synchronous composition. We have developped the R-PORTS (Rapid Prototyping Of Real-Time Systems)framework, which is grounded on mixed synchronous approach presented above, that provides automated distribution of control in an APS for a given target architecture. In our works, R-PORTS supports CAN/VAN fieldbus. A Middleware have also been developped to make synchronous these buses. This interface layer between the application process and the communication profile also integrates fault-tolerant politics. We call back the temporal consistency concept and we introduce an original notion: boolean sensibility. She characterizes the consequences of an erroneous signal applied on a system, within a given state.