Low Relaxation Prestressing Strand Tension Control System

Low relaxation prestressing strand has been widely used in the construction field due to its excellent performance. As the main force components, its quality directly affects the safety of the project. And in addition to the decision on the quality of the strand material itself, the most important factor is the production process of stabilization process, the "tension" and "tempered" thermo-mechanical process. Therefore, the paper studies strand production process, particularly its tension control to do a detailed study.This thesis introduces the low relaxation prestressing strand production process and the implementation process of each process, based on the detailed analysis of the production line, studies the realization process of multi-motor coordination and control of the control system, and through technological innovation, design a highly efficient, energy-strand control program.Then for low relaxation prestressing strand production process control theory and constant tension control carried out a detailed study, and using a cubic B-spline surface fitting control scheme fuzzy control algorithm for tension control, with the traditional fuzzy control algorithm, not only has good dynamic performance, and can effectively eliminate the steady state error and improve control accuracy, enhanced anti-jamming capability.Finally, the entire program is designed to control the tension control system based on Siemens S7-300 PLC as the core control system, consisting of the main connection via a PROFIBUS-DP bus with nine inverters from structure to AC motors as actuators, the use of industrial touch screen as the host computer, the tension sensor closed loop tension control system real-time detection strand tension. Also PLC and PC via RS-485 bus for connecting a touch screen and PLC, real-time monitoring of the current control system status, fault alarm and reset, and can be individual parameters touchscreen line to modify the system to change the system running.This project through installation and commissioning, production line in Tianjin factory has been put into operation, the system is stable and reliable to meet the performance requirements for products.