Condition Monitoring And Fault Diagnosis Of Industry Hybrid System Based On Petri Nets

Monitoring and diagnostic technology for industrial process is an important means and key technology in ensuring running stability and reliability of manufacture system, and in improving products' quality and production's benefit of the modern industry. Hybrid system is a kind of complicated dynamic variation system, which exists not only continuous dynamic variables but also gone with discrete logic variables. The miscellany performance is very common in the flow manufacture process. Based on certain solvent recovery technology, the Petri nets theory was introduced into the industrial hybrid system. A kind of solution method based on Petri net about monitor and diagnosis has been discussed in this paper. Firstly, a hybrid system about the start-up process of a leatheroid's DMF recovering plant has been studied, the hierarchical control model of this system was built using timed Petri nets and hybrid Petri nets theory. The monitoring method of start-up process was discussed by studying the coordination layer of this model, and the reachability method was adapted to analyze this model. Secondly, the monitoring and diagnostic integration concept was proposed for the hybrid system, based on this assumption, the monitor and diagnosis technology for running process of DMF recovering vaporizer was analyzed. The hybrid Petri nets information model describing the miscellany characterization for production process and controller model for diagnosis and decision were given. The combined propagation condition between equipment failure and heavy disturbance of continuous parameters was also discussed. The simulation results suggest that the methods in this work are valid.Based on above results, the simulation analysis method in Petri nets using MATLAB software was established, which provided a helpful tool for analyzing the hybrid system with Petri nets, furthermore, it gave a proof that the study method in this work is correct.