基于PLC及OPC通信的模糊PID控制实现

Realization of Fuzzy PID Control Based on PLC and OPC Communication

在烟草生产和加工领域的过程控制中,由于变量日趋多样化及复杂的外部执行环境,传统PID控制器暴露出其自身特有的局限性,有必要引入参数值在线实时调节功能。提出了基于OPC通信的模糊PID控制策略,基础PID控制算法经初步优化,通过编程在PLC上得以实现;基于OPC服务在底层与上位机之间产生数据交互,由上位机完成模糊推理过程,产生修正值并反馈PLC,有效结合了PLC的输出控制优势和上位机的复杂运算能力,从而实现参数的实时调整。试验结果表明,PID改良型控制器在稳态误差相同的情况下,调节时间较传统的PID控制器显著减少,并彻底消除超调现象,在高精度控制领域具有显著的推广意义。

In the process control of tobacco production and processing,the traditional PID controller exposes its own limitations due to the increasingly diversified variables and complex external execution environment. It is necessary to introduce real-time online parameter adjustment function. Fuzzy PID control strategy based on OPC communication is proposed. The basic PID control algorithm is optimized and realized on PLC by programming. Based on OPC service,data interaction is generated between the bottom and the upper computer. The upper computer completes the process of fuzzy reasoning,generates correction values and feeds back to the PLC. It effectively combines the advantages of the output control of the PLC and the complex operation ability of the upper computer,thus realizing the real-time adjustment of parameters. The experimental results show that,under the same steady-state error,the adjusting time of the improved PID controller is significantly shorter than that of the traditional PID controller,and the overshoot phenomenon is completely eliminated,which has significant promotion significance in the field of high-precision control.