| As the development of control science, electron and telecommunication technology, the traditional ingredient control system can not go well with the trend of intelligentization and informationization. To improve the precision and robustness of traditional PVC production and control system from the update of processes of a main producer of PVC gloves, here, it is deeply studied that how to advance the automization level of the ingredient control system and some key technology on improving the quality of ingredient.Firstly, some features on process flow and control system of PVC ingredient was analyzed, meanwhile, some key points determining the quality of ingredient was studied. So not only a reasonable solution is designed to improve the precision of ingredient, solid weighing and temperature autocontrol, but also the type selection, methods of installation and ways of control of some important hardware were mentioned according to the requirements of actual application in project.Secondly, traditional PLC control system in which the mainly electrical control cabinet installed in control room are away from the location equipment is installed usually needs a mass of cable that is linked between the I/O modules of PLC control system and remote devices installed in the work location. In addition, in the traditional PLC control system the signals between the main controller and the distributed devices are digital on/off of 24 voltage or analog of 4~20mA sensitive to disturbance. Given the shortage above, here a distributed control system using bus communication protocol is constructed at the time of a control method brought forward based on profibus. By putting the I/O modules near by the local devices the shortages of analog remote transmission are getted over, the workload of laying out cable is reduced obviouslyThirdly, the requirement of control precision is becoming higher and higher. More and more complex the control of process is becoming. Most of the control systems characterize time varying properties, large time delay and nonlinearity. It is difficult for these systems to design their math models. Classical cybernetics and modern cybernetics is difficult to meat the control requirements in practice applications, but the advanced control strategies show our great advantage when we try to control the above complex systems. So it has become a hot spot to research to combine the PLC control systems with advanced control strategies. This paper research the features of fuzzy control strategy, then introduce it into the temperature control of reaction jug. By combining the classical control strategy-PID with fuzzy control theory, a Fuzzy-PID controller is designed to temperature control. Finally, its effectiveness and reliability are proved.At the end, this paper describes the ingredient system's hardware configuration and its software design with a friendly HMI. |
