Diagnosis of critical embedded systems: application to the control card of a railway vehicle braking systems

Embedded systems are more and more used to control critical systems. In this paper, we propose a diagnostic approach to increase the security of control of critical embedded system based on digital components. This is a part of a study to design of an electronic card to control a railway vehicle braking system. Because of the critical aspect, it is necessary to diagnose the failures of the control card to process them online for safety purposes. In this paper, we propose to use diagnoser technique based on timed automata. But since this technique suffers of combinatorial explosion and because digital devices are characterized by a lot of input/output, our approach proposes to make an abstraction of the system behavior to reduce the size of the models and to implement a kind of distributed diagnosers.