Design Of Automatic Cross-cutting Production Line Based On PROFIBUS-DP

Cross-cutting production line is one of the important equipment which processes steel plate finely. After uncoiled by the strip uncoiler, the steel plate is straightened, and when the displacement comes to the specified length, the plate is sheared off by the plate shearing machine, and then it is stacked, packed and transported. The speed and precision of the shearing determines the quality of the product.With the development of industrialization and urbanization of our country, various industries need more and more steel plate. However, the production technology of many domestic steel companies is out of date.The traditional technology of cross-cutting is actually an iterative process to find cutting points, and the cutting precision is relatively low, while importing foreign technology and equipment will cost huge amount of money, therefore, many companies have to put a higher level of automation of production equipment in use.The automatic cross-cutting production line based on PROFIBUS-DP of Siping steel products Co.,Ltd. is designed in this situation. Fieldbus connects the intelligent devices and the automatic systems.It is mainly used to solve the problem of information transferred between industrial control devices and advanced control systems, and is widely used in manufacturing, process industries, transportation, housing, power electronics and other aspects of automation system. In this production line, SIMATIC S7-400 PLC is the master station, inverters of SIMOVERT MASTERDRIVES 6SE70 and remote distributed I/O devices are the slave stations.Master and slaves are connected by profibus-dp. We use SIMATIC WinCC V6.0 as the PC configuration software. By using the advanced technology, we not only improve the precision and productivity, but also enhance the intelligence and reliablity of the control system.Taking the actual situation of production into account, we use common DC bus technology as the drive control system. The rectifier unit of 6SE70 series of Siemens supply power for the common DC bus, which 16 inverters are attached to. In the condition of normal production, the power generated by the strip uncoiler is supplied to other motors by the common DC bus, and in this way, we not only reduce the probability of equipment failure, but also reduce the cost of production. How to determine the length of the steel plate is the key point of the control system, as it has a typical nonlinear characteristic, we use fuzzy control which is widely used in industrial control. After the actual production is fully estimated, we establish the rules of the fuzzy control. This gives full play to its non-linear function of automatic optimization, and it meets the requirement of the production.Synchronization is another key point of the control system, we must ensure that the rate of circle shear and straightening machine is synchronous, and this ensures the quality of the product.This thesis describes the control system of the cross-cutting production line in detail, it includes the determination of the overall control scheme, hardware configuration, programming, PC configuration, debugging and so on. We introduce the overview of the field bus, and study the application of fuzzy control technology in cross-cutting production line.