Fault Diagnosis Of Pneumatic Control Valve Based On The SVM

The control valve as the terminal control component in the industrial process control system,has a very important influence in control system to run safely and reliably.Due to the use of environment is relatively harsh,such as high temperature,high pressure,deep freezing,highly toxic,flammable and explosive,easily to penetration,easily to crystallization,corrosive and high viscosity,the control valve is easily to happen various faults.Once fault happened,it may be hard to imagine how terrible the consequence is,so finding faults in time and taking corresponding measures is the guarantee in the process of industry control system for its' safely,reliable and stable operation.In some foreign companies,the fault diagnosis of control valve has been as an important direction for research,and many related software,instruments,systems,and other products have been developed.In this paper,firstly introducing the structure and working principle of pneumatic control valve,summarizing several typical faults.On the control valve model based on the SIMULINK,adding fault modules for the control valve model,and several common faults of the control valve have been carried on the simulation and been analyzed,completing the work of modeling of the fault diagnosis of the control valve.Then,introducing SVM for fault diagnosis of control valve.after analyzing the shortcomings of the common practice,putting forward the improved SVM and used for fault diagnosis of pneumatic control valve.Although the improved SVM method can be used for fault diagnosis of pneumatic control valve,but the diagnosis results cannot satisfy us.Finally,I putted forward the fault diagnosis method based on the coding-SVM,used for fault diagnosis of the pneumatic control valve.Simulation results show that the method can be applied to the fault diagnosis of pneumatic control valve and achieved very satisfied results;Through experiment,I designed two faults of the pneumatic control valve,using this method to diagonize the fault data generated by the experiment,the results proving the fault diagnosis method based on coding-SVM in practical application can be used to the fault diagnosis of the pneumatic control valve.