基于物元标识的人机交互式机械排种器虚拟装配

为实现复杂机械式排种器智能化虚拟装配,集成2B-JP-FX系列双腔复合种盘机械式精密排种器的创新成果与专业知识,缩短设计与研发周期,该文提出了一种基于装配物元标识的智能装配系统。以双腔立式复合圆盘型号排种器为具体研究对象,分析各零部件间的装配关系,明确装配物元组成,完成装配物元的语义信息编码和装配参考的建立。基于CATIA(computer aided three-dimensional interactive application计算机辅助三维交互应用)的二次开发技术,以Visual Basic为开发语言,设计一种适用于物元标识的人机交互平台,可实现对装配语义集的提取与分析,将装配语义信息转化为装配约束,智能引导完成虚拟装配。测试结果证明了该系统的可行性和有效性,为2B-JP-FX系列排种器的研发提供了先进的虚拟仿真手段,也为机械装备数字化资源库奠定了技术基础。

Virtual assembly of man-machine interactive mechanical seed-metering device based on matter-element identification

Application of interactive and intelligent virtual reality assembly technology is still at the starting stage in China, especially in the field of agricultural machinery design and manufacture.In order to complete intelligent virtual assembly of complex mechanical seed-metering device, and integrate innovation achievements plus professional knowledge of the 2B-JP-FX series mechanical seed-metering device with double cavity composite plate, shorten design and development cycle, the 2B-JP-FX series of mechanical seed-metering device with double cavity composite plate were studied, and the man-machine interactive virtual assembly system was proposed based on matter-element identification.The concept of assembly matter-element is proposed, which is defined as general designation of assembly levels which includes assembly reference elements, type of assembly constraints and assembly direction.All the assembly information of assembly basic element and part can be expressed completely and accurately by the information of assembly matter-element.To realize assemble matter-element information identified and extracted by the intelligent assembly system, the assembly intention captured and assembly matter-element information was encoded into semantic encoding.Encoding rules meet the characteristics of integrality, universality, characteristic, uniqueness, comprehensiveness, computability and cleanness.Then, corresponding assembly reference element should be built, and assembly matter-element encoding identified in the 3D model file, so that encoding can be extracted by program.To transform assembly information into assembly constraints, and intelligently guide automatic assembly, the intelligent assembly system based on assembly matter-element identification was designed, with Visual Basic acting as development language and CATIA software as secondary development tool, and assisted by man-machine interface.CATIA software was accessed out-of-process through VB, then the assembly matter-element identification of all components were extracted, and the rules of corresponding information extraction were formulated based on the rules of assembly the matter-element identification, thus assembly information could be extracted and integrated, and was converted to assembly constraints.To make the system function more modular and operation simple, and meet a wide range of user groups, organic combination of human cognitive and logical operations of computer, a human-computer interaction interface was set in intelligent virtual assembly system.Main function of the interface was selection of the assembly sequence and guide of assembly.Results of system test proved that the system has got anticipated results, with rapid and accurate assembly of seed-metering device 3D model.The general rules of matter-element identification assembly was obtained, which was the basis of effectiveness and feasibility of the intelligent virtual assembly system.The system can not only propose an advanced virtual simulation method for researching the 2B-JP-FX series seed-metering device, but also lay technological foundation for digital repository of seed-metering device.Meanwhile, it provides reference for intelligent virtual assembly of other complicated mechanical equipment.