Key Points Research And Human Machine Interaction Design Of Automatic Control System For Stenter Frame

Stentering is an essential process in the fabric textile processing, it aims to broaden the fabric width to setpoint gradually, adjust the skewing, ultimately, drying setting. After the stentering process, the fabric can form a stable dimensional, a neat weft, a smooth cloth and a certain warp shrinking capacity.The paper,which is entrusted by Qing Dao Belle Maille Knitting Garments CO.,LTD, aims to design the automatic control system for the stenter frame production line, basing on its physical construction. The stenter farme automatic control system takes the S7-300PLC as master station, takes the twelve MM440inverter and ten ET200L/ET200M as slave stations, also a SIMATIC operator panel OP270is connected to the syetem. The PROFIBUS fileldbus guarantees the real-time, fast, accurate convey of control command and fieldbus data. With the friendly interactive interface of OP270, the input of process parameters and the real-time monitoring of process data are achieved easily, therefore, production management and equipment maintenance is possible.In the hardware design of the control system, several keypoints are designed. Such as speed loop control subsystem, width control subsystem, temperature control subsysetm, and operator monitoring subsystem design as well. In the speed loop control subsystem, which is constituted by chain, traction roller, overfeed roller, left/right shrink roller, take-off roller and plaiter roller, taking the VVF system while a Common DC Bus technology is adopted at the same time. PLC first caculates the speed of the seven motors respectively, then conveys the speed to corresponding inverter through the DP network. The inverters, in the speed loop subsystem, takes the Closed Loop Vector control mode.In the software design of the automatic control system, the PROFIBUS network configuration, PLC software and the HMI OP270configuration are designed. In the PLC user sofrware design, the program flow chart and the function of each block are described detailly. In the HMI network configuration, communication connection configuration, variable configuration, screen configuration, script configuration, alarm configuration and equipment setup are designed through the Wincc Flexible2008development environment. The fifth chapter of the paper introduces the installation and commission process of the control system. Firstly, the dimensional and layout of the power cabinet and control cabinets are designed according to the electrical schematic diagram and installation dimensions of the devices. Then proceeds to the installation and wiring of the electrical control system. Finally, power on operation and site commissioning are finished after security checking.The paper gives a summary of the control system at its final part, meanwhile, some improvement suggestion are maken according to the results of on-site commissioning.