数字化功能样机系统及在汽车设计中的应用

数字化功能样机( Functional Virtual Prototyping,FVP)技术是在CAD/ CAM/ CAE技术和虚拟样机(Virtual Prototype,VP)技术基础上发展起来的,并综合了近些年取得突破性进展的多领域物理系统(Multi-domain Physical System,MPS)建模与仿真技术,针对整个产品性能进行优化设计,是基于系统的优化设计,能通过虚拟试验精确、快捷地预测产品整机性能.对于汽车这样的多领域综合、复杂机-电-液-控产品,尤其适合采用数字化功能样机技术进行设计分析.该文介绍数字化功能样机系统研究开发的背景及数字化功能样机技术的发展状况与趋势,以及基于数字化功能样机系统进行汽车设计分析系统开发的情况.     

综合传动系统虚拟样机建模与仿真平台研究

液力机械综合传动系统是现代履带装甲车辆的主要传动形式,都为系列化产品.传动系统虚拟样机技术是提高设计质量,缩短研制周期的重要技术之一.通常的方法是采用分块建模,手动组装,效率低,难以满足新型传动系统及部件快速设计性能仿真的需要.采用自顶向下设计方法,基于模块化和参数化思想,以动力学软件ADAMS为开发平台,综合运用ADAMS/Solver语言和cmd命令建立一个以模块为基元、能够自动化搭建车辆传动系统的虚拟样机建模仿真平台.应用表明,该平台满足了传动系统性能仿真平台快速构建的需要,达到缩短传动系统的研制周期的目的.     

面向复杂系统工程的多学科统一建模与联合仿真技术研究与应用实践

多学科联合仿真技术应用工程背景 航空产品是涉及机械、电子、电气、控制、液压及软件等多学科,可靠性、维修性和保障性等多专业工程要求的复杂系统,其开发模式正经历从基于文档向基于模型的范式转移.建立以基于模型的系统工程方法论为指导、以功能/ 性能样机为载体,贯穿需求、功能、逻辑与物理构建模型在环、软件在环、硬件在环及人员在环的数字化综合仿真环境,开展多学科统一建模与联合仿真,实现功能/性能需求在开发早期阶段的验证与确认,基于数学模型(虚拟样机)开展复杂系统架构与方案的设计、权衡与分析优化,缩短设计迭代周期,提升开发质量,已成为国际航空航天和防务领域复杂系统开发的主流趋势.当前,基于Modelica语言的系统仿真技术已在达索航空、德宇航和空客得以工程应用,通过构建由功能样机、性能样机和几何样机组成的数字样机,可实现在虚拟空间下开展虚拟试验/试飞,极大的降低物理试验/试飞的周期与成本.     

红外成像导引头虚拟样机设计与仿真系统

虚拟样机技术是一种崭新的产品开发方法,它是一种基于产品的计算机仿真模型的数字化设计方法;利用虚拟样机可代替物理样机对产品进行创新设计、测试和评估;红外成像导引头涉及光、机、电、控制等多种技术专业范围,虚拟样机设计平台为红外成像导引头设计及仿真提供了虚拟样机环境,可以缩短导引头的开发周期,降低设计成本和风险;主要介绍了红外成像导引头虚拟样机设计与仿真系统的组成、功能,工作原理,并对基于虚拟样机设计与仿真系统的红外成像导引头研制流程进行了探讨;将虚拟样机设计与仿真系统应用于红外成像导引头的研制,可大大缩短其研制周期、降低研制成本.     

复杂产品虚拟样机数据管理研究

解决了复杂虚拟样机涉及的数据量大、人员分布广等问题,提出将产品数据管理运用到虚拟机床系统中的重要性.首先对虚拟样机,虚拟开发系统及产品数据管理做了概述.之后结合复杂产品虚拟样机的特点,总结出作为其支撑平台的产品数据管理系统所要具备的要求,针对这些要求重点研究了PDM系统的功能结构树.在对系统结构和功能分析的基础上,认为基于CORBA和Web的产品数据管理是适应复杂虚拟样机特点的有效手段,最后对其实现的技术路线进行了探索.     

机车车辆虚拟样机调度平台设计与开发*

简要介绍了机车车辆虚拟样机的发展现状,针对机车车辆虚拟样机系统协同设计的需求,提出了机车车辆虚拟样机调度平台,基于研究现状对该平台进行了功能的完善.按照协同的观点规范了机车车辆虚拟样机各部分的任务,并采用数据管理、子系统调控、文件管理、工作流管理、系统安全等技术,研究了基于产品数据管理的机车车辆虚拟样机调度平台的关键技术,开发了分布式网络工作环境下协同的机车车辆虚拟样机调度平台.通过初步试运行,表明该平台能有效地支持分布式网络工作环境下机车车辆虚拟样机的协同开发.     

基于Web服务的引信虚拟试验系统设计

阐述了在引信虚拟样机建模、虚拟目标建模和虚拟环境建模基础上所进行的虚拟试验系统设计与实现的技术途径和方法,论述了机电引信虚拟试验系统的功能模块,提出了其系统构成,并论述了系统实现中的关键技术.     

虚拟环境下机械装备故障预测理论与技术研究进展

在讨论故障诊断领域的研究现状的基础上,分析了机械故障预测技术的发展趋势,探讨了开展虚拟环境下机械故障预测技术研究的力学需求和动力学仿真需求,介绍了机械系统虚拟样机技术,分析了典型机械装备虚拟样机的建造方法及虚拟环境下的样机校核方法,提出了基于虚拟样机的故障仿真预测技术,设计了机械装备故障仿真预测系统的模块化结构,为实现机械故障的早期预测和预知维修开辟了新的思路,这是国际潮流的＂可持续发展思想＂和我国提出的＂清洁化生产模式＂在诊断工程中的具体体现,是现代诊断技术的＂可持续发展模式＂,具有良好的工程应用前景.     

基于核心软件的虚拟样机技术

一、虚拟样机技术的基本概念 虚拟样机技术(Virtual Prototyping,VP)是指在产品设计开发过程中,将分散的零部件设计和分析技术(指在某一系统中零部件的CAD和FEA技术)糅合在一起,在计算机上建造出产品的整体模型,并针对该产品在投入使用后的各种工况进行仿真分析,预测产品的整体性能,进而改进产品设计,提高产品性能的一种新技术.     

机械设备虚拟维修样机在虚拟环境中的实时移动

传统虚拟维修训练系统开发平台暴露出实时性差、维修数据与维修效果不同步、调整费时费力等问题;为了弥补开发平台的不足,使其达到“所见即所得”的维修效果,利用Creator和Vega在虚拟环境中引入虚拟维修样机的装配树形图,并建立起维修样机与装配树形图之间的实时响应,解决了维修样机部件的实时移动以及维修数据的动态存储等关键问题,从而实现了虚拟维修样机在虚拟环境中的实时移动,达到了“所见即所得”的维修效果;实践证明,改进后的系统实时性和通用性明显加强,操作流程更加人性化,达到了预期效果.     

飞行器性能样机虚拟试验系统研究与实现

为实现航天飞行器研制中性能样机模型的充分利用,提出了飞行器性能样机虚拟试验系统的总体方案,通过试验基础数据库、试验数据管理、验证辅助工具、虚拟试验应用等子系统划分和工作流程设计,提供对虚拟试验的全流程支持。系统突破了试验数据对象化管理、试验流程建模等关键技术,并基于虚拟试验支撑平台VITA完成了相应系统实现,在多个飞行器研制过程中开展了典型应用。     

Development of a heavy truck semi-active suspension control

The article describes the control design, the development process and the overall performance of a semi-active suspension control for a heavy truck. The control software is developed, debugged and preliminarily tuned within a dedicated Matlab/Simulink environment, in time and frequency domain, utilising a simplified vehicle model. After a preliminary virtual evaluation, the system performance is then tested on a real prototype truck, owing to the rapid prototyping technique application. A fine tuning of the system is realised through of an experimental test activity focused both on the comfort and the handling behaviour of the vehicle.     

Design and evaluation of virtual environments mechanisms to support remote collaboration on complex process diagrams

Many organizational analysis tasks are solved by collaborating teams. In technology-mediated collaborations, enabling relevant visual cues is a core issue with existing technology. We explore whether avatars can provide relevant cues in collaborative virtual environments. To do so, we develop a research prototype for a collaborative virtual environment that utilises avatars to improve workspace awareness in collaborative tasks. We test this solution through two studies, qualitative and quantitative, in which participants have to collaborate to jointly validate and correct a diagrammatic model of operational procedures.Our evaluations provide both positive and negative results about the proposed prototype. Collaboration patterns changed and became significantly easier, but, task performance was only slightly improved. Together, these findings inform both the ongoing development of collaborative 3D virtual environments and the role of technology-mediated collaboration for validating and fixing models of processes.     

基于Marc的螺旋钢弹簧卷制过程的仿真分析

弹簧作为车辆走行部的关键零部件,其性能质量直接影响行车的安全性,而弹簧卷制的质量直接影响着弹簧的性能.以某高速列车用螺旋弹簧为例,用Marc以及非线性分析方法和虚拟样机技术模拟弹簧卷制的实际过程,从而预测弹簧的成型过程、棒料的应力和应变、工装的应力和应变,优化弹簧卷制工艺,提高弹簧卷制工艺水平,达到提高产品质量和减少试制成本的目的.     

The Virtual Prototype Model Simulation on the Steady-state Machine Performance

Articulated tracked vehicles have high mobility and steering performance. The unique structure of articulated tracked vehicles can avoid the subsidence of tracks caused by high traction from instantaneous braking and steering. In order to improve the accuracy of the steady-state steering of the articulated tracked vehicle, the velocity of both sides of the track and the deflection angle of the articulated point need to match better to achieve the purpose of steering accurately and reduce energy consumption and wear of components. In this study, a virtual prototype model of the articulated tracked vehicle is established based on the multi-body dynamic software RecurDyn. The trend of the driving torque and power of each track changes as the velocity difference of two sides of the tracks and the traveling trajectory of the mass center of the front vehicle change in a specific condition are obtained by the experiment. The experimental results are compared and verified with the results obtained from the virtual prototype simulation. The change law of driving power in the steadystate steering process on the horizontal firm ground as changing the velocity difference of two sides of the tracks, the theoretical steering radius, and the ground friction is obtained by the virtual prototype model simulation analysis. The steering inaccuracy and track slip rate are used as indexes in evaluating the steady-state steering performance of the articulated tracked vehicle. The research provides references for the study of steady-state steering performance of articulated tracked vehicles.     

基于虚拟样机的协同设计技术

基于虚拟样机的协同设计技术是将协同设计技术应用到虚拟样机的开发过程中 ,可以大大简化机械产品的设计开发过程 ,大幅度缩短产品开发周期和降低开发费用 ,提高产品的系统级性能 ,获得最优化和创新的设计产品。针对虚拟样机技术的特点及其与协同设计的关系 ,提出虚拟样机协同设计的方法 ,并对虚拟样机协同设计环境基本结构及实现方案进行了介绍     

工业机器人虚拟样机系统的研究

该文提出将虚拟样机技术应用于工业机器人仿真研究过程，研究与开发工业机器人虚拟样机系统，首先说明虚拟样机技术并分析其关键技术，然后说明了工业机器人虚拟样机系统的构成与样机系统在机器人仿具研究中的研究内容，总结该项技术主要解决以下两方面的问题，即机器人仿真研究中的系统集成及为以机器人为主体的生产线虚拟设计，验证环境提供底层的数字化环境。     

基于强化学习的多目标车辆跟随决策算法

为满足自适应巡航系统跟车模式下的舒适性需求并兼顾车辆安全性和行车效率,解决已有算法泛化性和舒适性差的问题,基于深度确定性策略梯度算法(deep deterministic policy gradient,DDPG),提出一种新的多目标车辆跟随决策算法.根据跟随车辆与领航车辆的相互纵向运动学特性,建立车辆跟随过程的马尔可夫决策过程(Markov decision process,MDP)模型.结合最小安全距离模型,设计一个高效、舒适、安全的车辆跟随决策算法.为提高模型收敛速度,改进了DDPG算法经验样本的存储方式和抽取策略,根据经验样本重要性的不同,对样本进行分类存储和抽取.针对跟车过程的多目标结构,对奖赏函数进行模块化设计.最后,在仿真环境下进行测试,当测试环境和训练环境不同时,依然能顺利完成跟随任务,且性能优于已有跟随算法.     

Modeling and real-time simulation architectures for virtual prototyping of off-road vehicles

Virtual Reality-based simulation technology has evolved as a useful design and analysis tool at an early stage in the design for evaluating performance of human-operated agricultural and construction machinery. Detecting anomalies in the design prior to building physical prototypes and expensive testing leads to significant cost savings. The efficacy of such simulation technology depends on how realistically the simulation mimics the real-life operation of the machinery. It is therefore necessary to achieve ‘real-time’ dynamic simulation of such machines with operator-in-the-loop functionality. Such simulation often leads to intensive computational burdens. A distributed architecture was developed for off-road vehicle dynamic models and 3D graphics visualization to distribute the overall computational load of the system across multiple computational platforms. Multi-rate model simulation was also used to simulate various system dynamics with different integration time steps, so that the computational power can be distributed more intelligently. This architecture consisted of three major components: a dynamic model simulator, a virtual reality simulator for 3D graphics, and an interface to the controller and input hardware devices. Several off-road vehicle dynamics models were developed with varying degrees of fidelity, as well as automatic guidance controller models and a controller area network interface to embedded controllers and user input devices. The simulation architecture reduced the computational load to an individual machine and increased the real-time simulation capability with complex off-road vehicle system models and controllers. This architecture provides an environment to test virtual prototypes of the vehicle systems in real-time and the opportunity to test the functionality of newly developed controller software and hardware.