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时间:2019-03-03
《基于特征和约束的飞机反求建模》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、万方数据第41卷第5期2009年lO月南京航JournalofNanjing空航天大学学报UniversityofAeronautics&AstronauticsV01.41No.50ct.2009基于特征和约束的飞机反求建模谭昌柏1’2张丽艳1卫炜1王志国1周来水1(1.南京航空航天大学机电学院,南京.210016;2.昌河飞机工业(集团)有限责任公司博士后工作站,景德镇,333002)摘要:提出了基于特征和约束的飞机外形和结构件反求建模方法。针对飞机测量数据,运用内存映射和栅格划分技术进行预处理,在此基础上实现了针对大规模测量数据的平
2、滑、修复、多视拼合及区域划分算法。根据飞机外形特点,综合运用分片连续样条曲面、裁剪曲面、规则曲面和直纹面拟舍方法求取全机外形,采用曲面变形技术修改外形以满足必要的工裳约束,提出了基于曲面、实体特征分解的飞机结构件反求方法;设计了凸块、型腔等基本特征识别和参数提取算法,以及反隶平面轮廓线和辅助参数重建拉伸、旋转、扫掠等复杂轮廓特征的算法。对于二次曲面,识别曲面类型及约束,然后基于约束重建了曲面整体。对于飞机外形相关的结构件,当贴合面较窄、外形线接近于直线时,采用直纹面逼近,否则由蒙皮曲面等距间接求取。最后,各重建特征通过裁剪、缝合、特征融合
3、等操作得到最终实体模型。关键词:飞机;数据处理;模型重建;飞机建模中图分类号:TP391.7文献标识码:A文章编号:1005—2615(2009)05—0581-07AircraftModelReconstructionBasedonFeatureandConstraintTanChangbail“,ZhangLiyanl,WeiWeil,WangZhigu01,ZhouLaishuil(1.CollegeofMechanicalandElectricalEngineering,UniversityofAeronautics8LAstro
4、nautics,Nanjing,210016,China;2.Post—DoctoralScientificResearchStation,ChangheAircraftIndustriesGroup,Jingdezhen,333002,China)Abstract:Amethodologyforfeature&constraint—basedmodelreconstructionfortheaircraftcontourandstructuralpartsisproposed.Anapproachbasedonmemorymapping
5、andgridpar-titionisusedtOpreprocessthemassivemeasureddata.Thehighefficiencydataprocess,suchasdenoising,repairing,registration,andsegmentation,iscarriedout.Accordingtothechar—acteristicsoftheaircraftcontour,smoothpiecewisesplinesurface,trimmedsurface,regularsurface。andrule
6、dsurfaceareusedtOrebuildthesurfacemodeloftheaircraftcontour.Ifnee—essary,theresultingsurfacescanbemodifiedtoaccordwiththeconstraintsofexistingcrafte—quipments.Athoughtbasedonthesurfaceandthesolidfeaturedisassemblyisproposedforaircraftmodelreconstructionofstructuralparts.T
7、healgorithmsforthefeaturerecognitionandthefeatureparameterextractionaredesignedtoreconstructsuchelementaryfeaturesastheblockandthepocket.Theconstraint—basedquadricsurfacefittingisalsodiscussed.Forthestructuralpartconjointwiththeaircraftcontour,thesurfacefeatureconjoinings
8、kinwiththenarrowareaisapproximatedbytheruledsurface,andisgeneratedbytheoffsettingaircraftcontour
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