Research And Design Of PLC-based Control System For Shaping Machine

The global demand for medical protective fabrics,such as disposable masks and medical gowns,is increasing as a result of the outbreak of the new coronavirus,and machines and sizing equipment for processing wide technical fabrics and technical nets are becoming increasingly important.The shaping machine is a machine used for weaving and shaping,i.e.shaping textile materials such as chemical fibres,silk fabrics and cotton yarns,where the raw material is shaped and finished under a certain pressure and temperature to facilitate the subsequent processing of the finished product.The subject is the study and design of the control system of the shaping machine to address the problems of low precision and low level of automation in the process of sizing and finishing fabrics in the traditional shaping machine equipment.First of all,according to the process of fabric sizing and finishing,the key factors affecting the quality of sizing are analysed,and the control requirements of the system are clarified in combination with the production technology indexes;based on the analysis of the specific functions and realization principles of each module of the shaping machine equipment,the overall structure of the system and the control scheme of each controlled object are determined;in view of the many control objects of the shaping machine equipment and the relative distance of each module,this system adopts S7-200 smart series PLC as the master station,and with two PLC slave stations and a touch screen,the selection of the PROFINET communication protocol also ensures fast and accurate exchange of information between upstream and downstream devices.Secondly,the control objectives of each control unit are analysed in detail.For the problem of adaptive adjustment of temperature control,three power controllers were used as the main temperature controllers,a mathematical model of the hot air box temperature was created,an intelligent fuzzy adaptive PID control strategy was applied to temperature control,a model of the fuzzy adaptive PID control algorithm was created in MATLAB and SIMULINK was used for simulation analysis SIMULINK was used for simulation analysis.The results show that the fuzzy control algorithm has a good effect on the compensation of the PID parameters and has clear advantages for temperature control compared to conventional PID control strategies,allowing for a better optimisation of the system accuracy.Finally,the hardware and software are developed taking into account the control requirements of each of the control methods.The overall architecture of the control system is divided into an upper and a lower computer.The selection of the field devices and the design of the electrical circuits are made in accordance with safety and stability requirements.In the lower computer design,hierarchical control is achieved using a DCS control structure,and data exchange between all levels is achieved using the PROFINET communication protocol;MCGS configuration software is used to design the upper computer login system and monitoring screens.Centralised control is achieved;through the preliminary commissioning of the sizer control system in the laboratory and the functional commissioning in the industrial field,the effectiveness as well as the practicality of this control system was determined.