基于语义的虚拟装配建模及装配操作推理方法研究与应用
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摘要
在产品设计中,装配过程是影响产品开发周期和成本的重要因素之一。工艺规划是装配过程规划中的一个重要环节,影响着单个工位装配操作的劳动强度与工作效率。
基于虚拟现实技术的装配工艺规划为数字化产品装配规划提供了新的途径和方法,在这样一个虚拟装配试验环境中,人还是其中进行装配操作的主体,在计算机软件系统富有智能性的同时还能发挥人的知识与经验,也是装配工艺规划研究与发展的新趋势。
本文研究的面向产品装配的语义模型建模与生成方法和基于语义的自然交互式徒手虚拟装配操作方法,为虚拟装配工艺规划中装配工艺信息的获取奠定基础。同时从装配任务层次捕捉用户的交互意图,使得用户能够在虚拟环境中方便、准确地进行装配,使装配操作效率得到明显提升。
首先对交互虚拟装配操作中语义建模的功能需求进行了分析,在此基础上提出装配语义的定义。然后根据装配语义的定义,以功能特征为主要参考,对零部件之间的装配语义从顶层进行分类。最后为了支撑装配语义,提出基于语义的产品装配信息建模,并详细描述了零件模型、装配树模型、约束模型和语义模型,以及它们之间的内在联系。
其次,设计了在CAD系统中生成上述产品装配信息模型的方法。基本思路是先通过两次递归遍历访问当前模型的装配树结构,第一次递归遍历得到零件数据和装配数据的部分信息,如:零件和装配的组件路径、局部变换矩阵、层次结构等;第二次递归遍历得到约束数据信息,如:约束类型、偏置值、约束的组件几何引用项及装配引用几何项等;然后在此基础上交互式定义装配语义。在这过程中涉及约束顺序的确定、语义的查找匹配、语义参数的输入等。
再次,提出并实现了虚拟环境中对于语义的推理方法,包括语义的识别、确认、导航以及解算;以及在虚拟手单手交互操作过程中语义的处理方法,包括对虚拟手的抓取过程、移动过程和释放过程对语义的处理算法,并针对双手操作过程中出现的冲突提出了解决方案。
最后,将上述方法和技术应用于“基于虚拟现实环境的虚拟装配工艺规划系统VAPPE”的开发中,并通过汽车发动机装配工艺规划,验证了本文所述方法和算法的正确性与有效性。
In product design, assembly procedure is one of the key factors that affect product’s development cycle and cost. Process planning is an important link of assembly procedure planning because it will affect the assembly labor intensity and efficiency of the assembly operation on a single-position.
Assembly process planning based on virtual reality technology provides a new way for digital product assembly planning. In the virtual assembly test environment, people are still the main factor in assembly operation. Giving full play of both the intelligent computer software system and human’s knowledge and experience is a new trend of assembly process planning development.
This paper deeply studied assembly-oriented product semantic modeling and generation method and the nature interactive assembly operating technique based on semantic, thus laying solid foundation for the extracting ?of assembly process information. At the same time, the system can well capture the interactive intention from operation process perspective and enable users to assemble parts conveniently and accurately in the virtual assembly environment, thus improving assembly operation efficiency significantly.
This paper firstly conducted functional needs analysis for semantic modeling in virtual assembly operations, and then put forward the definition of assembly semantics. According to the definition of assembly semantics and based on functional characteristics, it classified the assembly semantic from the top-level. And in order to support the assembly semantics, this paper forwarded product assembly information modeling method based on semantic and gave a detailed description of the part model, the assembly tree model, the constraint model and the semantic model, as well as internal relations among them.
Secondly, this paper generated above-mentioned product assembly information model based on the research of CAD system. The idea is that: firstly, it visited the bottom data in CAD system through two recursive traversal of the assembly structure tree of the current model. The data of parts and assemblies such as component path、local transformation matrix and configuration are partially gained by the first recursive traversal, and the data of constrains such as constrain type,the offset value,the reference geometrical items of both assembly and component are gained by the second recursive traversal. On this basis, the users can define the semantics through interactive interface during which constrains binding, semantic matching and parameters inputting are involved.
Thirdly, this paper proposed and implemented the semantic reasoning method in virtual environment which includes semantic identification, confirmation as well as navigation and solution. Meanwhile, it also proposed semantic processing method in single virtual hand’s operation environment which includes the crawling, moving and release processes of virtual hands. And this paper also proposed solutions to deal with the conflicts caused by the operation of the both hands.
Finally, above methods and technology were applied in the Virtual Assembly Process Planning Environment (VAPPE). Then VAPPE was applied in an auto engine assembly process planning to validate the feasibility of the algorithms and methods proposed in this paper.
基于虚拟现实技术的装配工艺规划为数字化产品装配规划提供了新的途径和方法,在这样一个虚拟装配试验环境中,人还是其中进行装配操作的主体,在计算机软件系统富有智能性的同时还能发挥人的知识与经验,也是装配工艺规划研究与发展的新趋势。
本文研究的面向产品装配的语义模型建模与生成方法和基于语义的自然交互式徒手虚拟装配操作方法,为虚拟装配工艺规划中装配工艺信息的获取奠定基础。同时从装配任务层次捕捉用户的交互意图,使得用户能够在虚拟环境中方便、准确地进行装配,使装配操作效率得到明显提升。
首先对交互虚拟装配操作中语义建模的功能需求进行了分析,在此基础上提出装配语义的定义。然后根据装配语义的定义,以功能特征为主要参考,对零部件之间的装配语义从顶层进行分类。最后为了支撑装配语义,提出基于语义的产品装配信息建模,并详细描述了零件模型、装配树模型、约束模型和语义模型,以及它们之间的内在联系。
其次,设计了在CAD系统中生成上述产品装配信息模型的方法。基本思路是先通过两次递归遍历访问当前模型的装配树结构,第一次递归遍历得到零件数据和装配数据的部分信息,如:零件和装配的组件路径、局部变换矩阵、层次结构等;第二次递归遍历得到约束数据信息,如:约束类型、偏置值、约束的组件几何引用项及装配引用几何项等;然后在此基础上交互式定义装配语义。在这过程中涉及约束顺序的确定、语义的查找匹配、语义参数的输入等。
再次,提出并实现了虚拟环境中对于语义的推理方法,包括语义的识别、确认、导航以及解算;以及在虚拟手单手交互操作过程中语义的处理方法,包括对虚拟手的抓取过程、移动过程和释放过程对语义的处理算法,并针对双手操作过程中出现的冲突提出了解决方案。
最后,将上述方法和技术应用于“基于虚拟现实环境的虚拟装配工艺规划系统VAPPE”的开发中,并通过汽车发动机装配工艺规划,验证了本文所述方法和算法的正确性与有效性。
In product design, assembly procedure is one of the key factors that affect product’s development cycle and cost. Process planning is an important link of assembly procedure planning because it will affect the assembly labor intensity and efficiency of the assembly operation on a single-position.
Assembly process planning based on virtual reality technology provides a new way for digital product assembly planning. In the virtual assembly test environment, people are still the main factor in assembly operation. Giving full play of both the intelligent computer software system and human’s knowledge and experience is a new trend of assembly process planning development.
This paper deeply studied assembly-oriented product semantic modeling and generation method and the nature interactive assembly operating technique based on semantic, thus laying solid foundation for the extracting ?of assembly process information. At the same time, the system can well capture the interactive intention from operation process perspective and enable users to assemble parts conveniently and accurately in the virtual assembly environment, thus improving assembly operation efficiency significantly.
This paper firstly conducted functional needs analysis for semantic modeling in virtual assembly operations, and then put forward the definition of assembly semantics. According to the definition of assembly semantics and based on functional characteristics, it classified the assembly semantic from the top-level. And in order to support the assembly semantics, this paper forwarded product assembly information modeling method based on semantic and gave a detailed description of the part model, the assembly tree model, the constraint model and the semantic model, as well as internal relations among them.
Secondly, this paper generated above-mentioned product assembly information model based on the research of CAD system. The idea is that: firstly, it visited the bottom data in CAD system through two recursive traversal of the assembly structure tree of the current model. The data of parts and assemblies such as component path、local transformation matrix and configuration are partially gained by the first recursive traversal, and the data of constrains such as constrain type,the offset value,the reference geometrical items of both assembly and component are gained by the second recursive traversal. On this basis, the users can define the semantics through interactive interface during which constrains binding, semantic matching and parameters inputting are involved.
Thirdly, this paper proposed and implemented the semantic reasoning method in virtual environment which includes semantic identification, confirmation as well as navigation and solution. Meanwhile, it also proposed semantic processing method in single virtual hand’s operation environment which includes the crawling, moving and release processes of virtual hands. And this paper also proposed solutions to deal with the conflicts caused by the operation of the both hands.
Finally, above methods and technology were applied in the Virtual Assembly Process Planning Environment (VAPPE). Then VAPPE was applied in an auto engine assembly process planning to validate the feasibility of the algorithms and methods proposed in this paper.
引文
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[11] Zhang Shuyou, Liu Zhenyu,.Tan Jianrong, Research of guidance technology for assembly modeling in virtual environment. Chinese Journal of Mechanical Engineering. 2001, 14(2):139‐143.
[12] Tan Jianrong, Liu Zhenyu. Intelligent assembly modeling based on semantics knowledge in virtual environment. Proceedings of the 6th International Conference on CSCW in design, London, Ontario, Canada. 2001:568‐572.
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[27]李永立,张树有,刘振宇.VRML环境下基于语义的产品装配设计技术研究.计算机辅助设计与图形学学报[J]. 2003, 15(2): 209‐214.
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[30] Marcus S, Stout J, McDermott J. VT: an expert elevator designer that usesknowledge based backtracking. AI Magazine. 1987, 8(4): 41‐58.
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[40]武殿梁,杨润党,马登哲,范秀敏.集成虚拟环境中的多约束导航技术研究.机械工程学报. 2004, 40(11): 47‐52.
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[2] G. Boothroyd, Assembly Automation and Product Design, Marcel Dekker N Y. 1992.
[3]吴启迪.系统仿真与虚拟现实.化学工业出版社. 2002: 15‐17.
[4] Jayaram S, Kevin W Lyons et al, Virtual assembly using virtual reality techniques. Computer Aided Design. 1996, 23(8): 575‐584.
[5] Jayaram S et al, A virtual assembly design environment, Proceedings of IEEE Virtual Reality, Houston, TX. 1999: 172‐179.
[6] Jayaram S et al, VADE: a virtual assembly design environment, IEEE Computer Graphics and Application. 1999, 19(6): 44‐50.
[7] Bob K. A, A Synthetic Environment for Assembly Planning and Evaluation. Http://www.cs.uiowa.edu/‐cremer/.Sive‐abstracts/kuehne.text. 2005‐10‐9.
[8] Dewar R. G, Carpenter I. D, Richter J. M, Assembly Planning in a Virtual Environment, Proceeding of Portland International Conference on Management and Technology, Porland. 1997.
[9] Yuan Xiaobu, Gu Yiqing, Interactive assembly planning in virtual environment, Proceedings of 2000 IEEE/RSJ International Conference on Intelligent Robots and Systems. 2000: 1462‐1467.
[10]刘振宇,谭建荣,张树有.基于语义识别的虚拟装配运动导航研究.软件学报. 2002,3(13): 382‐389.
[11] Zhang Shuyou, Liu Zhenyu,.Tan Jianrong, Research of guidance technology for assembly modeling in virtual environment. Chinese Journal of Mechanical Engineering. 2001, 14(2):139‐143.
[12] Tan Jianrong, Liu Zhenyu. Intelligent assembly modeling based on semantics knowledge in virtual environment. Proceedings of the 6th International Conference on CSCW in design, London, Ontario, Canada. 2001:568‐572.
[13]万华根,高曙明,彭群生. VDVAS:一个集成的虚拟设计与装配系统,中国图象图形学报. 2002, 7(1):27‐35.
[14]范秀敏,马登哲,武殿梁.集成虚拟装配系统IVAE技术报告,上海交通大学CIM所. 2003.
[15] Lee, K. and Gossard. D.C. A hierarchical data structure for representing assemblies: part I. Computer‐Aided Design. 1985, 17(1):15‐19.
[16] Lee, K. and Andrews. D.C. A hierarchical data structure for representing assemblies: part II. Computer‐Aided Design. 1985, 17(1): 20‐24.
[17] Rocheleau.D.N and Lee, K. System for interactive assembly modeling. Computer‐Aided Design. 1987, 19(1): 65‐72.
[18] Kim.S.H. and Lee, K. An assembly modeling system for dynamic and kinematic analysis. Computer‐Aided Design. 1989, 21(1): 2‐12.
[19] Oliver.J.H. and Harangozo.M.J. Inference of link position for planar closed‐loop mechanisms. Computer‐Aided Design. 1992, 24(1): 18‐26.
[20] Haynes.L.S. and Morris.G.H. A formal approach to specify assembly operations. Int.J.Mach.Tool Manufacturing. 1998, 28(39): 281‐298.
[21] Rossignae.J.R. Constraints in constructive solid geometry’in Crow. F and Pizer.S.M.Eds. Proc. Workshop on Interactive 3D Graphics Chapel Hill, NC. 1996: 93‐110.
[22] Shah.J.J and Tadepalli.R. Feature based assembly modeling. Computer Engineering. 1998, 1: 253‐260.
[23] Shah.J.J and Rogers.M.T Assembly modeling and extension of feature‐based design. Res. Engineer Design. 1993, 5: 218‐237.
[24] Wang Hui, Xiang Dong, Duan Guanghong, Zhang Linxuan; Assembly planning based on semantic modeling approach; Computer in Industry. 2006.
[25]冯毅雄,谭建荣,郑兵,等.基于语义关联与驱动的产品概念装配模型研究[J].机械工程学报. 2004, 40(4): 114‐118.
[26]王辉,朱名铨,张林鍹,等.面向装配工艺规划的语义建模方法研究与应用[J].航空制造技术. 2003, 8: 38‐41.
[27]李永立,张树有,刘振宇.VRML环境下基于语义的产品装配设计技术研究.计算机辅助设计与图形学学报[J]. 2003, 15(2): 209‐214.
[28] Blach R, Landauer J, Rosch A, et al. A highly flexible virtual reality system. Feture Generation Computer Systems. 1998, 14(3,4): 167‐178.
[29] Gupta R, Whitney D, Zeltzer D. Research and development on constraint‐based product family design and assembly simulation. Journal of Marerials Processing Technology. 2003, 139(3): 257‐262.
[30] Marcus S, Stout J, McDermott J. VT: an expert elevator designer that usesknowledge based backtracking. AI Magazine. 1987, 8(4): 41‐58.
[31] Jayaram S, Connacher H I, Lyons K W. Virtual assembly using virtual reality techniques. Computer Aided Design. 1997, 29(8): 575‐584.
[32] Mullineux G.Constraint resolution using optimization techniques. Computers and Graphics. 2001, 25(3): 483‐492.
[33] Walsh G R. Methods of optimization. London: Wiley. 1975.
[34] Kramer G A. A geometric constraint engine. Artificial Intelligence. 1992, 58(3): 328‐355.
[35] Anantha R, Kramer G A, Crawford R H. Assembly modeling by geometric constraint satisfaction. CAD, 1996, 28(9): 707‐722.
[36]高瞻,张树有,顾嘉胤,等.虚拟现实环境下产品装配定位导航技术研究.中国机械工程,2002,13(11): 901‐904.
[37]刘振宇.面向过程与历史的虚拟环境中产品装配建模理论、方法及应用研究:[博士学位论文].杭州:浙江大学,2001.
[38]邓华林,IVAE中的交互操作技术研究,上海:上海交通大学硕士学位论文,2005.
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