Project : vertecs
Section: New Results
Supervisory Control of Structured Discrete Event Systems
Following our preliminary results on control of hierarchical systems , we first enriched the model by considering interactions between the components of the system in order to handle more realistic applications. In particular, given a system modeled as a structured discrete event systems, we have proposed a method solving the State avoidance Control Problem for a set of configurations of the system. Based on a particular decomposition of the set of forbidden configurations, we locally solve the control problem (i.e. on each component without computing the whole system) and we produce a global supervisor ensuring the desired property. This supervisor can be seen as an oracle that will activate/deactivate local supervisors according to the current configuration of the global system and some conditions that can be easily computed on the fly. Moreover, we make the necessary efforts to keep the structure of the plant in the global supervisor, hence improving the readability and the understanding of the supervisor effect as well as its memory storage   . We also developed a methodology allowing to control structured discrete event systems, when the control objectives are expressed in terms of languages. This work is still under progress.
These techniques has been implemented in a prototype, named Syntool. It is currently under testing.
A Model for the Automatic Generation of Safe Task Handlers
Participant : Hervé Marchand.
In collaboration with the BIP Project (now POP-ART) and VERIMAG, we have been interested in the programming of real-time control systems, such as in robotics or avionics. These systems are designed with multiple tasks, each with multiple modes. We propose a model of tasks in terms of transition systems, designed especially with the purpose of applying existing discrete controller synthesis techniques (based on the SIGALI framework). This provides us with a systematic methodology, for the automatic generation of safe task handlers, with the support of synchronous languages and associated tools for compilation and formal computation. This work is still under progress.