Design And Simulation Of Weft Knitting CAD System Based On Internet

Weft knitted fabrics are numerous and widely used,and their market demand continues to increase,weft knitting CAD(Computer Aided Design)technology has played an important role in modern weft knitting enterprises,its application can greatly improve efficiency and accuracy of product design and production.However,the 21 st century is the era of the Internet(5G era is approaching),big data,and information technology,the development of CAD technology has also received new opportunities and challenges.In response to the deficiencies of the existing Weft CAD systems which can only run on a stand-alone or local area network,weft knitted fabric CAD system is developed based on Internet by combining the network technology with database technology.It realized the first development of web weft-knit CAD system,greatly improving the informatization of enterprises and reducing the production cost.First of all,the architecture,function and interface of the Internet Weft knitting CAD system are designed.Based on the structure of B/S(browser/server),a three-layer network structure including presentation layer,service layer and data layer is designed,and the separation of data processing and display is realized.ASP.NET C#,SQL Server,Web service,IIS and other server-side technology are used for data interaction and data display,and HTML5,JavaScript,WebGL and other client technologies are applied to achieve data computing and data conversion.By analyzing the structure,representation and design process of weft-knitted fabrics,the functional module of weft-knitted fabric is designed,including five modules: the document management module,the pattern design module,the technique design module,the fabric simulation module and the database module.Meanwhile,the system interface with clear area and clear function is designed.The whole system function module is perfect,and the interface is friendly.Secondly,on the basis of deeply studying the Weft knitted fabric structure and the expressing method,this paper expresses it in mathematical language.The mathematic models of the Pattern design,the Technique design,cams view,Pareto pointer array view and the Arrangement of cams view are established using two-dimensional matrix,and the mathematic models of the fabric simulation view are established using three-dimensional matrix.For the technical view of double-sided multi-needle fabric,both the information of dial and cylinder are included.In order to facilitate the calculation,the mathematical model of the dial and the cylinder are respectively established.According to the ideal loop model of plain stitch,a ten-point ideal loop control point model of one-sided multi-needle stitch,double-sided multi-needle stitch,jacquard stitch,plush stitch,laying-in stitch and plating stitch is established.Finally,based on the established mathematical model,two-dimensional arrays and three-dimensional arrays are respectively used to define the weft-knit CAD data structure.It provides a theoretical basis for the transformation of the various models of the weft-knitted CAD system,and provides a data information source for the final generation of control files on the machine.Thirdly,the stitch structure of different kinds of weft knitting fabrics are studied,the corresponding representation methods are determined by them.And the transformation algorithms of different weft knitting fabric models are explored.The technical view,arrangement of cams view and pareto pointer array view are selected to show the multi-needle track fabric and pile fabric,and the transformation relationship between them is studied.The pattern view and technical view are selected to show the jacquard fabric,and the conversion algorithm from pattern view to the technical view of different kinds of jacquard fabrics is explored.In addition,the design methods of single striping jacquard fabrics,transfer jacquard fabrics and two-sided jacquard fabrics are discussed,and the conversion algorithm from the pattern view to the technical view is given.Finally,this paper focuses on the functional realization of the Internet weft knitting CAD system.The pattern view is directly drawn using Canvas drawing API;the technical view is accomplished through the method of creating primitives and mapping;and the two-dimensional simulation is realized by transparent maps method through the GDI+ drawing interface,the three-dimensional simulation is realized by adopting the WebGL technology.Through in-depth study of the control information of the on-machine files,fast export of the jacquard fabrics files—*.WAC and the seamless underwear files—*.JPX and *.ACX file is achieved;database function is realized by means of a connection to the SQL database.According to the characteristics of weft knitting fabric parameters,the weft knitting product database is established to ensure the safety,integrity and accuracy of the product data.Taking the design of multi-trach fabrics and jacquard fabrics as examples,the operation process of the system is introduced in the last of this paper.The test results show that the system is easy to operate and quick to respond.This paper uses Internet technology to develop a variety of functional Internet weft knitting fabrics CAD systems,such as interactive design,data export,network database,etc.This system can help users to design weft knitted fabric online anytime and anywhere,and provide technical support for intelligent design and intelligent analysis of weft knitted fabric in the future.