Design And Application Of AGC Control System In Strip Mill Based On Single-chip Microcomputer

There are about4thousands sets of strip mills, the installed capacity level of the mostmill is not high which producing low-end strip products, these mills are faced with themodification and replacement. With the control technology of hydraulic servo graduallymature, the replacement of these mills were powered by the hydraulic cylinder to pressed(pushed), and the response speed of the hydraulic pressed (pushed) is very fast(tens ofmilli seconds), which also require the control speed of the ancillary control equipment isvery high. Using the conventional PLC which use for process control is difficult to meetthe requirements, they generally equipped these conventional PLC with a high speedclosed loop module to control of the hydraulic cylinder’s closed-loop, so that the costsincrease dramatically.After years of practice, the authors developed a trip mill automatic gauge control(Automatic Gauge Control, AGC) system based on PIC (Peripheral Interface Controller)single-chip microcontroller, according to the control requirements of the general striprolling mill, completed the design of hardware and software. Microchip’s PIC24family of16-bit microcontroller is selected as the master chip of the system, as the same time, chosethe FPGA of Altera Corporation Cyclone II series which low-power and low-cost as anauxiliary chip to complete the data acquisition and processing of the encoder. The AGCcontrol system can greatly reducing the cost of the equipment update, and promote thetechnology upgrade of the whole rolled steel industry simultaneously.In this paper, according to the comprehensive analysis of strip mill AGC system,determined the master, auxiliary and function chip of the system. The method of use theAuxiliary chip to receive and process the signals of encoder has many advantages, such ascan not only improve the processing speed and anti-jamming capability, but also greatlysave MCU processing unit and the number of I/O ports. IN the light of the actualrequirements of the interface circuit of the AGC system, hardware circuit of the DI, DO iscompleted, as well as AD, DA. ON this basis, use the C language and VHDL language toprogram the whole system, at the same time, simulated of the entire system with Proteus. In the light of the requirements of the communication in the actual AGC system,RS-485is selected as the communication standard between the PC and controller in theAGC system, and follow the communication protocol designed the AGC system. In thispaper, the VB language is selected to program the display program of the PC, parameterscan be displayed in real time, and can manipulate the scene button, to achieve the purposeof real-time monitoring and on-site operation.