农业工程学报
農業工程學報
농업공정학보
2015年
11期
40-45
,共6页
逆向工程%三维%模型%导种管%Geomagic Design%几何模型
逆嚮工程%三維%模型%導種管%Geomagic Design%幾何模型
역향공정%삼유%모형%도충관%Geomagic Design%궤하모형
reverse engineering%three dimensional%models%seed tube%Geomagic Design%geometrical model
针对玉米精密播种机使用导种管的结构不合理导致株距均匀性差的问题，该文介绍了一种应用逆向工程设计软件Geomagic Design设计导种管的方法，研制性能优良的导种管。利用悬臂式三坐标测量机对进口曲线型导种管结构进行扫描，获取三维点云数据；通过三维逆向工程软件Geomagic Design减少噪音点、合并、简化、对齐等数据预处理获得网格数据；依照网格数据逐个创建特征重构导种管的三维几何模型；对重建的三维几何模型与网格数据进行误差分析实现三维几何模型的优化；依照所优化的三维几何模型生成工程图纸，完成导种管试制。在丰美2BQX-6玉米免耕精密播种机上进行了试制导种管、进口导种管和无导种管的性能对比试验，结果表明：试制导种管、进口导种管和无导种管的段粒数合格率分别为95%、97%和67%，空段率分别为3%、3%和33%，说明导种管可有效提高播种质量，且本研究试制的导种管与进口导种管性能相当。应用逆向工程设计导种管相对传统的理论研究和试验研究，可以缩短设计周期，降低设计成本；所建的三维几何模型为后续导种管结构研究和改进优化提供了一定参考。
針對玉米精密播種機使用導種管的結構不閤理導緻株距均勻性差的問題，該文介紹瞭一種應用逆嚮工程設計軟件Geomagic Design設計導種管的方法，研製性能優良的導種管。利用懸臂式三坐標測量機對進口麯線型導種管結構進行掃描，穫取三維點雲數據；通過三維逆嚮工程軟件Geomagic Design減少譟音點、閤併、簡化、對齊等數據預處理穫得網格數據；依照網格數據逐箇創建特徵重構導種管的三維幾何模型；對重建的三維幾何模型與網格數據進行誤差分析實現三維幾何模型的優化；依照所優化的三維幾何模型生成工程圖紙，完成導種管試製。在豐美2BQX-6玉米免耕精密播種機上進行瞭試製導種管、進口導種管和無導種管的性能對比試驗，結果錶明：試製導種管、進口導種管和無導種管的段粒數閤格率分彆為95%、97%和67%，空段率分彆為3%、3%和33%，說明導種管可有效提高播種質量，且本研究試製的導種管與進口導種管性能相噹。應用逆嚮工程設計導種管相對傳統的理論研究和試驗研究，可以縮短設計週期，降低設計成本；所建的三維幾何模型為後續導種管結構研究和改進優化提供瞭一定參攷。
침대옥미정밀파충궤사용도충관적결구불합리도치주거균균성차적문제，해문개소료일충응용역향공정설계연건Geomagic Design설계도충관적방법，연제성능우량적도충관。이용현비식삼좌표측량궤대진구곡선형도충관결구진행소묘，획취삼유점운수거；통과삼유역향공정연건Geomagic Design감소조음점、합병、간화、대제등수거예처리획득망격수거；의조망격수거축개창건특정중구도충관적삼유궤하모형；대중건적삼유궤하모형여망격수거진행오차분석실현삼유궤하모형적우화；의조소우화적삼유궤하모형생성공정도지，완성도충관시제。재봉미2BQX-6옥미면경정밀파충궤상진행료시제도충관、진구도충관화무도충관적성능대비시험，결과표명：시제도충관、진구도충관화무도충관적단립수합격솔분별위95%、97%화67%，공단솔분별위3%、3%화33%，설명도충관가유효제고파충질량，차본연구시제적도충관여진구도충관성능상당。응용역향공정설계도충관상대전통적이론연구화시험연구，가이축단설계주기，강저설계성본；소건적삼유궤하모형위후속도충관결구연구화개진우화제공료일정삼고。
In order to improve the performance of seed tube and solve the problem of bad uniformity of seed spacing caused by unreasonable seed tube structure, this study introduced a method of applying reverse engineering design software Geomagic Design to design seed tube. Reverse engineering is a kind of technology that builds engineering model of products or parts according to prototypes of current products or parts, and then analyzes and improves them. As a new product design method, it plays an important role in absorbing advanced manufacturing technology at home and abroad, shortening product development cycle and reducing production cost. Seed tube is mainly applied in precision planter, which is used to shorten the distance between metering point and dropping point, reduce seed horizontal speed variance between different metering speeds and reduce seed bounce in dropping and falling processes, in order to realize zero-speed dropping seed and make sure of good uniformity of seed spacing. The length of linear part, the angle between linear part and horizontal direction, the curvature of arc part, the central angle of arc part, the cross-sectional area and the smooth degree etc all have significant impact on seed dropping performance. The imported curve-type seed tube was scanned by non-contact laser scanning method of three-coordinate measuring instrument and the three-dimensional (3D) point clouds were obtained. The front and back of the seed tube were scanned respectively in order to get the complete point cloud data; to make the point clouds better matched with the scanned seed tube, unrelated scanned data were deleted through 3D reverse engineering software Geomagic Design, data preprocessing like reducing noise, merging, simplifying, alignment etc. was done, and then the mesh data of seed tube were got. Through the application of 3D reverse engineering software Geomagic Design, based on the mesh data, and by the application features design tools in “design” interface, coordinate system, tube body, semicircle groove, hanger and strip rib and other features were created one by one, and the 3D geometrical model of seed tube was re-built. Error analysis for the re-built 3D geometrical model and the mesh data was done in “measure” interface, and different colors were used to distinguish different errors. If there were large errors, then back to “design” interface and adjust the corresponding features to reduce error and optimize 3D model. The seed tube was trial-produced according to the engineering drawings which were generated from the optimized 3D geometric model. According to the national standard GB/T 20865-2007, the test was done with Fengmei 2BQX-6 corn no-tillage precision seeder, and the performances were compared among the trial seed tube, imported seed tube and without seed tube. Taking the qualified rate of seed number and the no-seed rate in seed channel as the test indices, make a continuous measurement of 100 segments, and the theoretical length of a segment was 250 mm. The results showed that the qualified rates of seed number in seed channel for the trial seed tube, imported seed tube and without seed tube were 95%, 97% and 67% respectively; the no-seed rates in seed channel were 3%, 3% and 33% respectively. It can draw the conclusions that seed tubes can effectively improve seeding quality, and the performance of the trial seed tube is good and equivalent to the imported seed tube. This research can be successfully applied on seed tube design. Applying reverse engineering for designing the seed tube can shorten the design time and reduce the design cost compared with theoretical study and experimental study. The built 3D geometric model provides a certain reference for the improvement and optimization of seed tube.
