Development of extended safe petri net model for discrete system control and scanning algorithm for real time control

비연속 시스템 제어를 위한 확장된 safe petri net 모델과 실시간제어를 위한 scanning algorithm의 개발

Recently, in sequence control systems, high flexibility and maintenance of control software are required. This is because product life cycles become shorter and control specification must be changed frequently. The authors extend the concept of Safe Petri Net to develop the design and analysis tool for sequence control systems taking the safeness and notation of input/output functions into consideration. Extended Safe Petri Net (S-Net) is proposed as such a new graph model and real time scanning algorithm based on S-Net is developed.