Supervisory control after perturbation

Discrete event systems undergo perturbations, such as failures, that disrupt the control system and reduce the anticipation capacities of the future evolution of the process. Using the (max,+) algebra, processes modelled by a timed event graph may be represented by a linear model. The knowledge of the model and of the initial conditions enable one to characterize the state vector with a state equation iteration, but perturbations may generate a misappreciation of the state vector. This paper estimates the unknown state in order to predict the output trajectory and to calculate the control when the state vector is unknown