Safe switching of discrete events systems: Application to operating mode management

Based on operating mode management, this paper introduces a framework to help study the dynamics of Discrete Event Systems (DES). Studied systems present several operating modes thus causing complexity of state space explosion. For this, we propose a multi-model approach and each model describes a system in a given operating mode. We assume that only one attempted operating mode is activated at a time, whilst other modes must be inactivated. In order to ensure the alternation between these operating modes, we propose a theoretical approach formalized by linear algebra. The commutation problem can be defined as compatibility problem when the behavior of the physical system switches from an operating mode to another. The compatibility problem is treated as the consistency of current states when a mode generates an event activating the other mode. For this purpose, we introduce a definition of compatible state and propose mathematical techniques to determine this current state in mode switching.