Design And Research On Control System Of Dual Power Pillow-packaging Machine

The pillow-packaging machine is a continous packaging device, whichwraps and seals three-sided products with flexible materials, having been widelyused in food, medicine, daily necessities and other fields. On the basis of the deepstudy on the control system of the pillow-packaging machine, their intelligentlevel of control system determines the degree of automation, therefore it’s verynecessary for us to design a kind of control systems, which could enhance thereliability, improve the degree of automation, offer the convenience of operatingand provide a widespread applications for the packager.After analyzing the packaging process related to the machine, a kind ofelectric control scheme based on the PLC was proposed: the control system ofthe dual power scheme of transmission. Then dual power transmission schemeof the control system was researched and implemented from the combination ofhardware and software both to satisfy the following requirements ofpillow-packaging machine.Firstly, the capacity of production was adjustable in succession withinallowable limits;Secondly, the bag length could be adjusted in succession within limits;Thirdly, the real-time bag length could be displayed;Fourthly, the patterns should be kept intact when the bags were cut off.The electrical control system was studied and designed this paper, whichcould satisfy the control requirements of color-code tracking, variable speed, thereal-time display of bag length and the adjustable temperature. With the help ofrotary encoder, photoelectric sensors and HMI, the bag length could be displayedat all times. The VFD (Variable-frequency Drive) was selected to adjust speed,then the capacity of the packing could be changed. Temperature controller wasused in terms of sealing temperature, which could regulate the sealingtemperature of the bag. A way of color-code compensation was put forward, making the color-code tracking compensation system more reliable and accurateand also guaranteeing the integrity of patterns on the bags when they were cut off.Moreover, communication connection and format, and their parameter settingwere designed between PLC and personal computer, between PLC and HMI,between PLC and servo drives. The control program based on PLC werecompiled while corresponding HMI screen was also designed.Finally, frequency control experiments of main motor and color-code trackingcompensation experiments of servo motor were completed, achieving the mainmotor continous speed control and color-code tracking compensation control in alaboratory environment.