目的 针对给袋式包装机称量控制系统中由于物料与电磁振动给料机的振动存在一定非线性与时变性的缺点，提出一种基于PLC的模糊PID称量控制系统。方法 基于PLC的特点设计一种基于PLC的模糊PID控制方法，将称量误差与误差变化率作为系统的输入，采用西门子S7-200系列PLC对称量系统模糊PID控制策略的实现进行分析设计，实现对PID 3个参数的实时改变；基于Matlab对控制系统进行仿真分析，并通过联机运行以验证控制效果。结果 给袋式包装机称量系统的计量偏差不超过0.5%，且仿真结果表明模糊PID较传统PID的控制效果更好。结论 基于PLC的包装机称量系统模糊PID控制系统实际控制稳定，具有很强的鲁棒性，提高了包装机称量过程的稳定性和称量精度，其精度控制为0.5%左右。

The work aims to propose a fuzzy PID weighing control system based on PLC to solve the problem of non-linearity and time variability in the weighing control system of bag-delivering packaging machine due to the vibration of materials and electromagnetic vibrating feeders. Based on the characteristics of PLC, a fuzzy PID control method based on PLC was designed. Weighing error and error change rate were used as system inputs. Siemens S7-200 series PLC was used to analyze and design the implementation of fuzzy PID control strategy for the weighing system and realize real-time change of three PID parameters. The control system was simulated and analyzed based on Matlab, and the control effect was verified through online operation. The measurement deviation of the weighing system of the bag-delivering packaging machine was less than 0.5%, and the simulation results showed that the fuzzy PID control effect was better than the traditional PID control effect. The fuzzy PID control system of the packaging machine weighing system based on PLC has stable actual control and strong robustness, which improves the stability and weighing accuracy of the packaging machine weighing process; and its precision control is about 0.5%.