UNIFIED LOGICAL MODEL TO IDENTIFY FAULTS IN A PLC CONTROLLED MANUFACTURING SYSTEM
Arup Ghosh, Gi-Nam Wang, Jooyeoun Lee · International journal of industrial engineering · 2017
In this paper, we present a novel approach that can identify operational faults associated with control process by using log data records of the PLC program signals. The proposed approach automatically creates a logical model, called unified logical model, of the control process, and detects faults by using that model. The unified logical model includes the signal-state logical models of the devices, and the relational logical models of the device groups. The signal-state logical model is modeled to depict a device behavior, and the relational logical model is designed to describe the relationships among the dependent devices. The proposed approach automatically generates the unified logical model from the log data records, and employs a hash table based model indexing and fault searching scheme to identify the faults in the manufacturing system. Experimental results show that the proposed model can be utilized to detect the faults effectively.