Filter Tip Forming Units Of Automatic Control System Development And Research

Filter Plug Making Machine Group is imported from Germany in 1980s. In the past ten year's running, it mainly has the following problems: its electrical control system is made up of discrete components, which results in malfunctions frequently; there are too many filters blown away at the paper-agglutinating time; it can't stop automatically when the filter is blocked; The fluctuating range of the temperature is wide; The mechanical structure of its synchronizing driving system is very complicated and has a low efficiency.We rebuild its control system with SIEMENS S7-PLC and design a data acquisition system with industry control configuration software. This system has been working very well in the past half a year.The monitoring system designed with ProTool software has rich human-machine interfaces and flexible methods to deal with data. These enable the operator or technician to find the malfunctions or hidden troubles. They can also use the history records to analyze process of manufacture and find out how to improve productivity. The monitoring system also can provide the processing data for data-base management system of factory. We adopt the impulses counting method to control the blow-divice in the paper-agglutinating time and the number of filer blown out has been reduced, thus make the best use of the raw materials. PLC can judge whether the filter is blocked and when the machine must be stopped. These reduce the waste product rate greatly.Temperature-controlling system of this groups make up of two parts. Owing to disturb factors, such as plus of the P.V.A glue, machine failure, the average PID controller can not adapt to the running process. Thus we design a time optimal PID controller base on specialist rules to regulate the temperature. The time optimal PID controler is actually a compound controller which based on PID control algorithm and the Bang-Bang control algorithm. We program the computer to do the Bang-bang control and the PID control instead of the average PID control. The application of this function block is very simple and also can be easy debugged before running. It has accomplished very good results.In this paper we introduce the method of speed regulation by frequency inverters to replace the former mechanical system. To deal with the nonlinearity and time-varying parameters of A.C motor, the compound 'Fuzzy-PID' control strategy is proposed. Weuse the Fuzzy Logic control to optimize the three parameters when the system is disturbed by outside interferences. Introducing the PID controler eliminate the static error when the error is small. The fuzzy logic rule can improve the PID control performance and increase response speed by optimizing the PID parameters real time. The application of this system will make the servicing easy and improve the efficiency.