Force Feedback Coupling with Dynamics for Physical Simulation of Product Assembly and Operation Performance

Most existing force feedback methods are still difficult to meet the requirements of real-time force calculation in virtual assembly and operation with complex objects. In addition, there is often an assumption that the controlled objects are completely flee and the target object is only completely fixed or flee, thus, the dynamics of the kinematic chain where the controlled objects are located are neglected during the physical simulation of the product manipulation with force feedback interaction. This paper proposes a physical simulation method of product assembly and operation manipulation based on statistically learned contact force prediction model and the coupling of force feedback and dynamics. In the proposed method, based on hidden Markov model （HMM） and local weighting learning （LWL）, contact force prediction model is constructed, which can estimate the contact force in real time during interaction. Based on computational load balance model, the computing resources are dynamically assigned and the dynamics integral step is optimized. In addition, smoothing process is performed to the force feedback on the synchronization points. Consequently, we can solve the coupling and synchronization problems of high-frequency feedback force servo. low-frequency dynamics solver servo and scene rendering servo, and realize highly stable and accurate force feedback in the physical simulation of product assembly and operation manipulation. This research proposes a physical simulation method of product assembly and operation manipulation.

Creation and Evaluation of a Multi-sensory Virtual Assembly Environment

The multi-modal information presentation, integrated into the virtual environment （VE）, has potential for stimulating different senses, improving the user＇s impression of immersion, and increasing the amount of information that is accepted and processed by the user＇s perception system. The increase of the useful feedback information may reduce the user＇s cognitive load, thus enhancing the user＇s efficiency and performance while interacting with VEs. This paper presents our creation of a multi-sensory virtual assembly environment （VAE） and the evaluation of the effects of multi-sensory feedback on the usability. The VAE brings together complex technologies such as constraint-based assembly simulation, optical motion tracking technology, and real-time 3D sound generation technology around a virtual reality workbench and a common software platform. The usability evaluation is in terms of its three attributes： efficiency of use, user satisfaction, and reliability. These are addressed by using task completion times （TCTs）, questionnaires, and human performance error rates （HPERs）, respectively. Two assembly tasks have been used to perform the experiments, using sixteen participants. The outcomes showed that the multi-sensory feedback could improve the usability. They also indicated that the integrated feedback offered better usability than either feedback used in isolation. Most participants preferred the integrated feedback to either feedback （visual or auditory） or no feedback. The participants＇ comments demonstrated that nonrealistic or inappropriate feedback had negative effects on the usability, and easily made them feel frustrated. The possible reasons behind the outcomes are also analysed by using a unifying human computer interaction framework. The implications, concluded from the outcomes of this work, can serve as useful guidelines for improving VE system design and implementation.

Application of Assembly Modeling and Simulation Technology to a Large Size Wind-drive Generator

Challenges still remain in carrying out assembly modeling efficiently in virtual assembly （VA） fields. One of the root causes is the apparent weakness in effective description of assembly knowledge and information. The assembly modeling, disassembly modeling, assembly interference inspection, assembly sequence planning and optimization, and assembly simulation display for key techniques is studied theoretically in this paper. An example of product assembly modeling is provided to illustrate the effectiveness of the proposed approach. On the basis of re- search, using assembly simulation techniques and multimedia techniques to finish structure design in linkage design of a large size wind-drive generator. The application of the modeling method has shortened the lead time dramatically.

Comparison of the Feasible Schemes for HT-7U Assembly Simulation

The whole superconducting HT-7U Tokamak is a high-cost and large-scale complicated device. The assembly requirement of HT-7U device is arduous and strict. At present, there have been no guiding principle for the assembly of the device, but assembly simulation can help the engineer plan and make decision by an intuitional and visual way before its actual assembly. The problem is that which scheme is most suitable should be solved primarily. From current research situation and technology progress of assembly simulation, this paper explained and analyzed four kinds of technological schemes of assembly simulation in common use. Finally, we got the most feasible scheme that was suitable for HT-7U assembly simulation by comparing their technological issues and difficult points of simulation among the four kinds of feasible schemes.

Virtual assembly framework for performance analysis of large optics

Background A longstanding technological challenge exists regarding the precise assembly design and performance optimization of large optics in high power laser facilities,comprising a combination of many complex problems involving mechanical,material,and laser beam physics.Method In this study,an augmented virtual assembly framework based on a multiphysics analysis and digital simulation is presented for the assembly optimization of large optics.This framework focuses on the fundamental impact of the structural and assembly parameters of a product on its optical performance;three-dimensional simulation technologies improve the accuracy and measurability of the impact.Intelligent iterative computation algorithms have been developed to optimize the assembly plan of large optics,which are significantly affected by a series of constraints including dynamic loads and nonlinear ambient excitations.Results Finally,using a 410-mm-aperture frequency converter as the study case,we present a detailed illustration and discussion to validate the performance of the proposed system in large optics assembly and installation engineering.

Universal Mechanism Modeling Method in Virtual Assembly Environment

Motion simulation and performance analysis of mechanism are important methods for analyzing assembly quality after finishing assembly simulation in virtual assembly environment. However, most simulation systems have no function of mechanism motion simulation due to the randomicity of mechanism and lack of universal mechanism modeling method. In order to realize the simulation of any mechanism after finishing assembly simulation in a virtual environment, a new universal mechanism modeling method is presented. Two main models are contained in the mechanism model： information model and mathematical model. Firstly, the information model of mechanism is proposed to describe the data structure of mechanism which contains bottom geometry data, information of constraint, link, kinematic pair and physical data. Because the object of mechanism simulation is the assembly, which is assembled during the process of assembly simulation, the information of mechanism can be obtained automatically through mechanism automatic search method. Secondly, mathematical model of mechanism is presented. The mathematical model uses mathematical method to express the mechanism. In order to realize the automatic expression of any random mechanism, basic constraint library is presented, consequently random mechanism can be described based on the basic constraint library. Finally, two examples are introduced to validate the method in the prototype system named VAPP（Virtual Assembly Process Planning）. The validation result shows that the mechanism modeling provides a universal modeling method for mechanism motion simulation in virtual assembly environment. This research has important effect on the development both of mechanism motion simulation and virtual assembly.

Digital assembly technology based on augmented reality and digital twins: a review

Product assembly simulation is considered as one of the key technologies in the process of complex product design and manufacturing.Virtual assembly realizes the assembly process design,verification,and optimization of complex products in the virtual environment,which plays an active and effective role in improving the assembly quality and efficiency of complex products.In recent years,augmented reality(AR)and digital twin(DT)technology have brought new opportunities and challenges to the digital assembly of complex products owing to their characteristics of virtual reality fusion and interactive control.This paper expounds the concept and connotation of AR,enumerates a typical AR assembly system structure,analyzes the key technologies and applications of AR in digital assembly,and notes that DT technology is the future development trend of intelligent assembly research.

虚拟仿真技术引导汽车构造拆装实验系统开发

针对传统的汽车拆装训练在时间和空间上的学习限制,设计并开发了汽车构造拆装训练及展示系统,该系统包括基于虚拟现实的汽车构造拆装实验和基于增强现实的汽车构造拆装展示,通过丰富多样的学习方式,加强学生对汽车内部结构的认识和了解。汽车构造拆装训练及展示采用3Ds MAX制作了零部件拆装动画,以汽车的发动机、车轮、悬挂系统、制动系统、转向系统五大零部件为学习对象,基于Unity 3D软件、Holo Lens1代设计开发,实现了汽车部件拆装的理论学习、拆装逻辑实操、考核一体化的虚拟拆装训练与展示系统。该系统的全新体验方式激发了学生的学习兴趣、规范学生拆装过程中的操作步骤,进一步强化和巩固理论教学知识学习,并有效降低了教学成本和时间成本。

基于虚拟仿真技术的收割机零部件智能化装配研究

为准确实现收割机零部件智能化装配,并获取最佳收割机零部件智能化装配路径,该文设计了基于虚拟仿真技术的收割机零部件智能化装配方法。首先采用Pro/E软件构建收割机零部件三维模型;然后构建收割机零部件智能化装配结构树模型反映收割机与零部件间的父子关联特性,并设计零部件装配约束条件,以约束条件完成收割机零部件智能化装配;最后利用遗传蚁群算法获取收割机零部件智能化装配规划的最佳路径。实验表明,该方法既可实现收割机零部件智能化装配,又可计算出收割机零部件智能化装配规划的最佳路径,提升收割机的智能化装配速度。

液压调平举升平台虚拟拆装系统研究

在维修和培训过程中,机电产品的虚拟拆装系统可以降低对硬件设备的依赖,能够减少设备的损耗。通过研究液压调平举升平台的VR(Virtual Reality)拆装系统,分析其结构组成和工作原理,基于Unity3D开发环境,编写交互脚本,以HTC Vive Pro2.0作为交互设备,完成了三维模型的构建与处理、虚拟场景的设计、碰撞检测、拆装序列规划、交互功能的设计、用户界面的设计以及拆装功能的设计,开发出沉浸式人机交互的虚拟拆装系统,实现场景漫游、结构认知、拆装引导和虚拟拆装训练等功能。实验结果表明:所开发的虚拟拆装系统沉浸性良好,交互方便,虚拟拆装训练效率高。

VR技术在船舶分段装配实训教学中的应用

VR技术与传统教学的融合是现阶段教育教学的一个发展趋势。基于当前VR技术在实训教学中的现状,探讨VR技术在船舶分段装配仿真实训教学中的作用和意义,并具体分析了VR技术在船舶分段装配实训教学中的应用。通过调查分析证明了VR技术在船舶分段装配仿真实训教学中的应用效果,最后提出推进VR技术在船舶分段装配仿真实训教学中的具体操作建议。

隧道掘进机快速拆装举撑液压系统仿真

针对隧道掘进机(TBM)在施工现场因空间限制无法满足调试所需较大空地的问题,设计一种用于TBM洞内快速拆装变位的举撑液压系统。该液压系统由4组顶升单元构成,通过4组顶升单元同步运动实现TBM的起吊和举撑;液压顶升单元由4根四级液压缸、液压控制系统、激光位移传感器和机架构成。基于AMESim建立四级液压缸、变量泵和比例节流阀以及整个顶升单元的液压仿真模型,通过仿真分析负载下液压缸运动的速度、位移和压力曲线。结果表明:改变比例节流阀的输入信号可以实现四级液压缸速度的变化;泵出口压力可由比例溢流阀调整;在2.5×105 N的额定负载下,四级缸的换级工作腔压力逐级上升;随着换级,活塞杆伸出速度逐渐上升。与理论计算对比显示,建立的TBM洞内快速拆装液压系统顶升单元的AMESim仿真结果和理论值基本吻合。

基于元宇宙的职业教育虚拟仿真实训系统设计——以“计算机组装与维护”课程为例

当前,职业教育虚拟仿真实训系统的设计多强调知识传递和操作技能培训,其固化的程序逻辑限制了学习者的自主决策权,忽视工作内涵的复杂性。为解决上述问题,利用元宇宙的媒介、场域和生态属性,构建包含场景层、关联层、工作层和评估层的系统设计框架,并以高职“计算机组装与维护”课程为例设计了基于元宇宙的职业教育虚拟仿真实训系统。系统能为学习者提供综合性工作任务以及符合职业发展规律的学习路径,支持学习者在虚拟环境中开展基于工作的学习,提升综合职业素质与行动能力。

面向航空发动机的虚拟多人拆装任务的驱动方法

为满足虚拟多人协同拆装系统不同拆装任务的快速开发需求,提出一种可配置任务序列的数据驱动方法。以某型航空发动机样机为研究对象,研究了多人协同拆装的任务要素,对任务进行基于JS对象图谱(JavaScript Object notation,JSON)的参数化设计与表达,以JSON参数化文件驱动任务序列,定义每一步任务的交互操作。实践表明:该方法运用于多人协同拆装系统中,使系统具备可配置性,能根据自定义任务序列驱动任务流程;在多端大任务量的情况下,有效提升部署效率。

基于虚拟现实技术的船舶装配工艺仿真优化

传统依靠人工经验或者试错法的船舶装配不仅耗费大量的时间,同时也会给船舶装配带来极大的不确定性。本文将虚拟现实技术应用于船舶装配中,对船舶装配工艺仿真优化进行相关研究。构建船舶虚拟装配环境,包括虚拟装配建模、装配序列规划、装配路径规划、装配干涉检测、可达性分析以及装配过程仿真。船舶设计数据、装配工艺数据、虚拟环境数据以及人机交互数据为构建船舶虚拟装配工艺优化提供数据基础。使用数字化编号可以优化装配序列规划,采用包围盒法对虚拟模型碰撞检测进行优化,通过对比发现,优化后包围盒在空间上明显大幅减小,降低了不同零件模型之间的碰撞风险。

基于数字孪生的桌面型机器人装配工作台研究

基于数字孪生技术创建了桌面机器人装配工作台数字孪生系统,并基于此系统进行了装配控制优化研究。分析了数字孪生系统的架构和关键技术;结合桌面机器人装配台,构建了数字化仿真模型,并结合典型的装配任务进行了虚拟仿真调试,既可验证数字化模型的正确性,又验证了控制程序的正确性,为下一步数字孪生系统的实现打下基础;通过设置虚实协同调试通信,实现了桌面机器人装配工作台数字孪生系统的虚实协同调试;利用数字孪生平台发现影响装配效率的主要因素并据此优化了装配控制流程,使装配效率提升了18.75%。结果表明:所提出的桌面型机器人装配工作台数字孪生平台的方法是可行的,为从虚拟产品、虚拟生产到实际生产的企业数字化实践提供参考和借鉴。

基于SolidWorks的导线卡线器三维建模及运动仿真

为解决导线挂线时的滑线、跑线问题,提高卡线器的设计效率,通过分析卡线器的结构和工作原理,以SKLT-60卡线器为主要研究对象,基于三维软件SolidWorks及其Motion插件,进行零件建模、虚拟装配及运动仿真,得到卡线器的夹嘴夹持力、上夹嘴运动轨迹、摇杆极限位置及滑块行程随时间的变化曲线.仿真结果表明:夹嘴夹持力、传动角及拉环行程满足设计要求.将虚拟样机技术和运动仿真技术相结合,对卡线器进行仿真分析,具有较好的模拟效果,缩短了产品开发周期,还能根据仿真结果进行结构优化,为类似设计提供了一种快捷、可靠的方法.

基于液压电磁换向阀的船用机电设备虚拟拆装系统

以液压电磁换向阀的拆装为例,研究开发对于船用机电设备虚拟拆装的方法。旨在研究能在电脑上独立运行操作的拆装系统,使用3ds Max创建拆装模型,使用Unity 3D引擎工具创建虚拟维修环境,实现对机电设备的拆装操作。通过交互式虚拟拆装体验式学习提升了学习主动性和积极性,在实际教学过程中取得一致好评,加深学员对于机电设备的认知水平。作为一种学习模式的变革,对于虚拟系统在机电设备中的发展应用具有一定的参考价值。

单缸内燃机拆装与机械结构分析虚拟仿真实验开发和教学设计

结合新工科背景下智能制造大类人才培养的要求,将虚拟仿真技术应用于较高复杂度和集成度的综合实验教学,建立了单缸内燃机拆装与机械结构分析虚拟仿真实验系统。该虚拟仿真实验以单缸内燃机的工作原理介绍、机械结构组成、关键部件特征、拆装工艺流程和零件力学分析为主要内容,通过教学视频、文字介绍、模型拆装和实物展示等方式引导学生开展虚拟仿真实验。学生首先通过虚拟仿真实验系统的基础学习模块进行模型认知和理论学习;然后通过机械结构与分析中的“模型展示”“虚拟实验”“计算分析”和“知识测验”功能,分别进行操作训练、基于操纵步骤提示的拆装实践、理论知识测试考核以及零部件静力学性能计算;最后,虚拟仿真实验系统可以详细记录学生实验过程并自主评分,通过实验报告模块生成报告并完成实验。按照虚实结合和线上线下结合的思路开展实验教学,有效提升教学效果和实验效率,为智能制造大类人才的实践教学和综合能力培养提供了重要支撑。

飞机结构静强度试验虚拟装配与干涉检查技术

地面试验是目前航空结构最重要的一种验证手段,为保障复杂杠杆加载系统在飞机大变形下的安全性,对飞机结构试验系统的虚拟装配技术进行了研究,建立了基于XML的虚拟装配模板,研发了可扩展的试验设备模型库,在CATIA平台下实现了试验加载与支持系统的虚拟装配。提出了一种杠杆加载系统运动平衡方程和迭代求解方法,根据飞机结构仿真变形计算得到各加载步加载设备的空间位置,并采用坐标转换实现加载设备在加载过程中的运动模拟,同时对加载运动过程中多加载通道之间、加载系统与支持系统之间进行碰撞检查。算例表明能够发现碰撞干涉问题,为试验设计与实施提供技术支撑,降低试验风险。