Using firing instants approach and partial order to control time critical systems

Time-critical systems are characterized by operation times included between a minimum and a maximum value. A transgression of these specifications acts again the quality of service. In this paper, a dynamic robust control is proposed to cancel as quickly as possible the effects of a delay or an advance on a planned task. P-time Petri Net is used as modeling tool and the control is based on an extension of the firing instant approach permitting negative instants to update the tasks scheduling. The illustration of the method is made on a graphite ceramic cell.