Design Of Automatic Control Sysyem For Spiral Pipe Production Line Based On S7-300

The paper, which is entrusted by Shandong Yong Tai Iron and Steel Technology Co., Ltd., aims to design the automatic control system of spiral pipe production line. Two Parts is included, one is design of the control system of steel transmission part, and another is transformation of pipe transportation car system.The whole control system is designed using PROFIBUS-DP network, and S7-300 CPU315-2DP as the master station, and four ET200M (slave station), and three SIMOREG DC Masters (6RA70), one All-digital AC MM440, and one MP277(Touch Panel). Transmission velocity of PROFIBUS-DP network can reach 12Mbit/s, delaying time being short, precision being improved significantly.Techinics parameters can be set and revised using touch panel MP277. Output records and alarm information, Start and stop of masterdrives, and speed of masterdrivers can be monitored and checked. all kinds of malfunctions can be repaired rapidly, manufacturing techinics being perfected and manufacturing efficiency being improved. DC Master 6RA70 can communicate with master station with CBP2 board. What's more,6RA70 DC Master has strong diagnostics function. And it makes the debugging simple.The crucial technology of the steel transmission control system can keep speed of the delivery machine and the moving car synchronously during the process of steel welding. Therefore, we can weld the two rolls of steel while keeping operation. Meanwhile, the delivery machine and the levelling machine should be controlled in phase when they are working in-line. To deal with nonlinearity and time-varying parameters of AC motor, the compound'Fuzzy-PID'control strategy is proposed. We use the Fuzzy Logic control to optimize the three parameters with external disturbance. Static-steady error can be eliminated with the aid of PID controller. The fuzzy logic rule can improve the PID control performance and increase response speed by optimizing the PID parameters in real time. As a result, efficiency of this system improves significantly.The delivery car is another equipment in spiral pipe production. Based on the delivery car's characteristic, delivery car is controlled by MITSUBISHI FX2N-32MR PLC and SIEMENS MM440 converter. Hardware and software is accomplished.So far, the spiral pipe production line has been running effectively for one year. What's more, the molding quality of the spiral pipe has been improved significantly. the rate of the whole line breakdown is reduced greatly, the efficiency being improved.