With the increasing levels of China’s steel and automation, many strip mills of thesteel production enterprises are facing reconstruction and replacement. With the hydraulicservo control technology matures, ancillary control equipment requires higher controlspeed. Although using SIMATIC TDC or PLC can achieve a good result, the cost is toohigh and it is hard to repair. It is urgent to design a high-performance and low-cost AGCcontroller.After years of research and practice, This paper developed an automatic thicknesscontrol system based on PIC microcontroller. Using the PIC24H series which is the16bitsingle chip of Microchip company as the main control chip, while using the FPGA ofAltera’s CycloneⅡseries as an auxiliary chip. The control system hardware circuit isdesigned based on the general performance requirements of strip mills. It is includesanalog input and output interface circuits, digital input and output interface circuits, theencoder interface circuits, communications interface circuits, and power part circuits.Using C language and combine the various parts of the chip timing and usage toprogram on the PIC microcontroller after the success of debugging the system hardwarecircuit. The software program of all the interface circuits were written on the MPLABplatform. While the FPGA using VHDL language to program to achieve the function ofencoder part, and finally through the PCB board to experimental verification. The systemsuccessfully achieved the live input signal acquisition and processing, and the output ofcontrol signal, the real-time communication between PC and microcontroller via RS485.The overall flow of AGC control system was built based on all these and the program ofthe position closed-loop, pressure closed-loop based on the PID in the timer interrupt andthe thickness advanced control, the thickness gauge control was programmed and wasproved by the semi physical simulation. Depending on the process of AGC and the actualneeds of the controller, This paper join the intelligent control algorithm based ontraditional PID control algorithm, design fuzzy PID controller for closed-loop controlsystem and show the feasibility of the algorithm through MATLAB simulation. It improved the control performance and control accuracy.The AGC control system has fast speed of operation, strong anti-interference abilityand good practicality, can greatly reduce the cost of upgrading equipment and promotetechnological upgrading of rolling industry. |