Research On Parameter Matching Technology And Method Of Threshing And Cleaning Device

Agricultural machinery equipment in China is developing in the direction of control intelligence,green manufacturing and high efficient operation.Knowledge-based design method and digital design system based on CAX and PDM are important approaches to intelligent design of agricultural machinery.Under the traditional research and development mode,the emphasis of agricultural machinery equipment research and development is mainly on the overall layout of the whole machine and the structural design of the key parts.When forming engineering drawings and technical data of the whole machine,designers are required to consult a large number of design information such as formulas,manuals,industry standards,and draw out all the mechanisms and standard parts to meet the design requirements of the whole machine.The design cycle is prolonged and the work efficiency is reduced.In addition,under this research and development mode,the knowledge inheritance and reusability of agricultural machinery equipment is poor and the deformation design is difficult.As complex agricultural machinery,the design of combine harvester depends to a great extent on the work experience of designers,and there is no complete expression system for the knowledge of parameters,formulas,standards and calculation processes involved in the design process.But in the practical product design,there are many kinds of problems,such as complex variety of design knowledge,involving many parameters,complex interaction,large calculation,cumbersome calculation method,long design cycle,difficult to complete the optimization of parameters matching design,and so on,which make the modeling process more difficult.The aim of this paper was to build a research platform for parameter optimization matching technology,which was based on the threshing and cleaning equipment of the key parts of the combine harvester.A knowledge-based parameter optimization matching method was designed to realize reasonable matching between threshing and cleaning device structure parameters and working parameters.Using secondary development technology realized the design functions of model parameterization and model drive for threshing and cleaning device.The specific contents of the study was as follows:(1)Analysis of research object: The main research object of this paper was threshing and cleaning device,which was the key component of combine harvester.In the design process of threshing and cleaning equipment,there were many parameters involved and the interaction between them was complex.It was necessary to clarify the relationship between parameters and classify the parameters reasonably in order to complete the process of parameter optimization and matching design better.(2)Knowledge modeling and expression of design process: Design was actually a process of dynamic solution in problem domain.In order to realize design reuse,it was necessary to model the whole design process,not just to model the design result.Therefore,the design process tree corresponding to the case tree of threshing and cleaning device can be established to express the design information of the whole parameter relationship and design flow of threshing and cleaning device.(3)Solid modeling and parameterization: Product modeling technology was the core of digital design technology.In this paper,CATIA knowledge engineering module and top-down correlation design method were used to establish parametric model of parts and components,for fully expressing three-dimensional structure and design information of the threshing and cleaning device.(4)Interactive design system: In this paper,integrated development system Visual Studio 2015 and visual programming language VB.NET 2015 were used to compile the parameter optimization matching system of threshing and cleaning equipment.The process of parameter optimization matching between threshing and cleaning device was completed through human-computer interface,and the parametric model was modified by the design parameter drive of the system to get the desired model.The results of research and example analysis show: The optimization matching system of threshing and cleaning device parameters can complete the optimization matching of structure parameters and working parameters,and drive the parametric model to change the parameters to get the product model which meets the design requirements,which can improve product design efficiency,shorten research and development cycles,and enhance knowledge inheritance and reusability.It can lay the technical foundation for the establishment of intelligent design platform for agricultural machinery and equipment,and provide reference for the research of similar parameter optimization matching technology.