基于增量PID算法的包装机滤纸放卷控制

Filter Paper Uncoiling Control of Packaging Machine Based on Incremental PID Algorithm

针对袋泡茶包装过程中滤纸卷随时间推移直径变小导致走纸张力不稳定的问题,设计搭建基于PLC、变频器、触摸屏的不间断放卷控制系统,采用增量PID算法,利用PLC和触摸屏完成PID数据通讯与处理,以角度变送传感器测量压纸辊角度来间接反映纸卷直径的时移变化,通过A/D与D/A转换及反馈处理,得出适时控制量信号给变频器以驱动放卷电机放卷走纸。实践表明,系统可精确控制滤纸卷放卷,在纸卷直径不断变化的情况下能始终保持走纸线速度和张力恒定。

In view of the problem of unstable paper feeding tension in the teabag packaging process due to the diameter of filter paper roll becoming smaller with time,a filter paper uncoiling control system based on PLC,frequency converter and touch screen was designed. Using the incremental PID algorithm,the PID data communication and data processing were achieved by the PLC and touch screen,the paper roll angle was measured by the angle-displacement transmitter to reflect the real-time change of the paper roll diameter,and obtain the real-time control variable which was used by the frequency converter to drive the motor to uncoil the filter paper through the A/D and D/A converter and feedback processing. Practice shows that the system can accurately control uncoiling of filter paper,and can keep the line speed and the paper tension constant all the time even when the diameter of the paper roll constantly varies with time.