Rotary Screen Printing Machine Control System Design Based On The Bus

To improve the synchronization control precision is the key technology of the control system of rotary screen printer. This paper focuses on the "multi-electromotor isolated synchronization control" as the main study objection. For the multi-electromotor synchronization control belongs to the nonlinear control field, it is difficult to express the detailed mathematic model. Hence, the paper adopts the Fuzzy Logic Control/PID control strategy, which measures the feedback motor rotating speed signals, and setup speed error signal e, ratio of speed difference Δe, and changes the precision value into fuzzy value through fuzzy inference E/EC. Then, the system fuzzy control value U is calculated and get thefinal control value u. In this way, the close loop feedback control method of the controlled objection is realized and the multi-motor synchronization control is realized.This paper analyzes and studies the characteristics of PLC, fully masters the speed-adjusting principle, combines the cost, reliability, and anti-interference ability. Under these bases, this paper designs the general method of the rotary screen printer which integrates the SIEMENSS7-300, HMI TP277, bus double MM440converter, high precision asynchronous electromotor, and so on. This system has the characteristics of simple structure, low cost, high control precision, and so on. The test proves this system could satisfy the requirements of printing industry.The main work of this paper is to supply the general design scheme of the synchronization control system, establish PLC control system, PID arithmetic study and design, and program for software STEP7, WINCC flexible and so on. Firstly, rotary screen printer movement and the working principle of asynchronous electromotor are analyzed and the two-way1.5KW converter is chosen. Through calculate the controlled nodes, reliability and manufactory cost, SIEMENSS7-300PLC is chosen as the main controller. Combined the fuzzy control PID compensator control strategy, the control precision effect test is performed for DP&RS485buses and identify the bus and the adjusting coefficient majorization of the fuzzy PID converter. Here, the converter control method and program design based on USS communication and the communication interactive between PLC& TP277are discussed. This communication adopts free interface to realize the serial communication between PLC and touch screen to upload the data of converter into the touch screen through S7-300, so as to design the monitoring program to realize control the working state of motors and monitor the coefficients in real-time through operate on the touch screen. In this system, HMI touch screen is used to realize the monitor the printing process, data record, technique choosing, and set the PID running coefficients, at the same time, online measure the motor running state and remote brake. In this way, the locating lines in field is reduced, automatic level and anti-interference ability, and system reliability is improved.