Improvement Of AgriDEM Software Boundary Modeling Module

Our country is a big agricultural country.Although our economy has been developing continuously for many years,it has not been ranked as a powerful agricultural country.One of the reasons is that our country has been in a self-sufficient small-scale peasant economy for a long time,resulting in a low degree of mechanization and not reaching the level of a powerful agricultural country.In many rural areas,the harvesting of crops is entirely dependent on manual labor.In recent years,more and more attention has been paid to agricultural mechanization and its automation.However,due to the fact that the design and manufacture of mechanical structures mostly rely on past experience,the design cycle is long and the accuracy is not enough.It is necessary to use computer simulation to assist design.If the simulation results are not satisfactory,it can be directly returned to redesign.On the one hand,the design cycle can be shortened.On the other hand,it can save resources and design the most satisfactory mechanical products.Under the above background,our team independently developed a three-dimensional discrete element method simulation software AgriDEM,which can simulate the collision between mechanical structure and crop particles by using the discrete element method,and analyze the results mechanically.Before this process,there is an important pretreatment process-boundary modeling.Through the boundary modeling of the designed mechanical structure,AgriDEM software can obtain the data information of the mechanical structure,and the quality of modeling directly affects the results of simulation calculation.In order to obtain accurate data information,our team developed the extraction modeling program Menu31 on the basis of Pro/E software.It can use regular surface modeling and grid modeling to extract the location,movement,material and other attributes of mechanical parts and store them in the database.However,the Menu31 program is limited by Pro/E software platform and can not be used in all CAD software.Therefore,the research team has developed a boundary modeling program based on STL file,which is a general format file that can be exported by all CAD software.In this way,the boundary modeling process can get rid of dependence on specific software platform and improve the efficiency of modeling.Based on the two existing boundary modeling programs,this paper extends and improves the functions of these two programs,which makes the boundary modeling module of AgriDEM software more perfect.Firstly,multi-thread-based multi-selection and box selection functions are addedto Menu31 program to improve the extraction efficiency.Then the extraction and modeling algorithms of belt conveyor,bucket elevator and elastic boundary are designed and implemented,and the existing multi-rigid-body modeling functions are improved to lay the foundation for the multi-rigid-body dynamic model.Secondly,for the boundary modeling program based on STL file,the function of component recognition is studied and implemented,so that the problem that the original program can not set the motion and material attributes of each component separately can be solved.Several STL files have been added to build models together,which makes it possible for different mechanical structures to build models together.Then the boundary modeling function based on STL file is optimized to improve the efficiency of software simulation calculation.In the program,OpenGL technology is applied to render the display of the model,and then several kinds of boundary modeling functions of complex moving machinery parts are studied and implemented to make the boundary modeling program more perfect.In addition,after improving the boundary modeling module,the other functions of AgriDEM software are extended and improved,including adding reciprocating motion function to the boundary motion attributes to enable friction and wear tests to be carried out;then the aspheric particle modeling program is improved to provide a better user experience;in order to adapt to the computer screen with all resolutions,the research is carried out.The software copyright page is automatically adjusted according to the screen resolution.Then the "stop computing" function is added to the DEM calculation.Then the authentication function is added to the Menu31 program,which effectively protects the intellectual property of the program.Finally,the key functions of the extended boundary modeling module are tested and verified.The test results show that the extended and improved functions are correct and can achieve the desired results.