Design And Implement Of The Experimental Control System In Modified Cotton And Flax Yarn

Modified technology of Cotton and Flax Yarn is a kind of method which can change the properties of textile yarn through the modification medium in a certain temperature and pressure,after that,the crystal structure of fiber yarn will be changed and the cellulose I form will be converted into cellulose III form of nature fiber yarn,in a word,this technology is effectively increase the added value of the apparel products.In foreign countries,the continuous and large quantity's automation equipment which been used for fabrics had been successfully applied,but had not the relevant reports which were applied to yarn.At the nation level,although some manufacturers had introduced some continuous modified equipment,but its one-time investment was high,only suitable for large-scale production,did not meet our country's apparel industry which had a small quantity and variety,rapid recovery funds for the market demand,in addition,the study of domestic about modified automation equipment in yarn is still relatively less.Therefore,designing a kind of high degree of automation and intermittent modified equipment will have important social and economic significance to meet the need of China's national conditions.In this thesis,the control object is the intermittent modification process,the design and realization of whole modified control system is achieved.Firstly,according to the distribution of local equipments,the type of control system is designed.The modified process equipments contains vacuum pump?compressor?vane pump and so on.Therefore,the distributed control system was chose to be the type of control system.Secondly,the hardware configuration was achieved based on quantities and types of the equipments.The control system was composed of industry computer?process parameter acquisition card?PLC and local equipments.Among them,the industrial computer as the upper layer of the entire control system,responsible for monitoring and operation management of modification process;PLC as the lower layer was responsible for the control of actuators,process parameter acquisition card was responsible for realizing information collection to local equipments;the universal serial bus was chose to realize data exchange.Then,according to the actual process control requirements,the software program of control system was finished.The software design mainly contained PLC program?acquisition card program and host computer monitor interface program.The operation of single equipment?single modified process technology and the automatic operation of the entire process could be achieved by PLC;the sensor output 4?20mA current signal would be transformed to digital signal by process parameters acquisition card program,after the conversion was completed,the digital signal would be passed to the host computer and PLC;the host computer software program was developed by Visual Basic.Net,which can design and realize the human-machine interface.Human-machine interface mainly contained database and the function of picture,the database took charge of the historical data record of the preservation;function of picture included alarm?user login?the parameters of real-time display and so on,they realized the monitor and record of important technical parameters.Finally,aiming at the problems of the time-varying?nonlinearity and difficult to establish accurate mathematical models for removing residual medium by microwave in modified cotton and flax yarn,a strong robustness?high precision control and easy to project implementation's control strategy was developed for removing residual medium by microwave,and because the microwave can't meet the need of fuzzy algorithm,so this chapter as the theory reference for the follow-up study.The modified control system in the thesis was used in reality,it runs steadily,and the anticipated purpose is achieved.