【作者】 王政；

【导师】 谭建荣；

【作者基本信息】 浙江大学 ， 机械设计及理论， 2005， 博士

【摘要】 在产品开发中，由于物理样机的成本较高，为了保证方案的可靠性及早期得到不同分系统集成的关系，可采用计算机辅助的方法。在最简单的情况下，借助渲染利用几何数据，可以产生产品的逼真效果图。利用数字虚拟样机，将产生能用此方式评价的三维模型。这种数字表示方法也可用来模拟空间大小、干涉及功能关系。数字样机的内容不仅仅涉及几何信息，而且虚拟现实系统还提供了人机交互存储现实三维场景的工具，在计算机内成像，使观察者可以评价复杂的图像场景。除了虚拟三维空间的导航功能和交互修补外，虚拟现实系统存在着考虑干涉、计算模型或运动模型等物理边界条件的可能性。而且，虚拟样机集成了关于信息建模、实时感知和多通道交互等方面的研究成果，覆盖了产品从设计、工作性能分析、零部件加工、装配到使用等环节，为产品创新开发提供了直接的三维界面和虚拟测试平台。 本文同绕上述领域，在面向产品创新开发的虚拟设计平台研究中，针对虚拟样机动力学求解器的软件实现，在以下方面进行重点研究： (1) 在虚拟样机核心仿真模型构建中，提出了由机械系统CAD模型建立面向领域行为模型的方法。机械系统内部约束基于CAD描述，构件间的关联通过图论表达，在软件实现时，基于构件的交互端口建立行为模型，由CAD模型推导出的3D机构图表达了系统中的能量流，而CAD模型和组件行为参数化的同时，也保证了两者的一致性。在软件组件中，封装了设计信息、行为模型及其内部关系，对其实例化后，以端口连接配置复杂系统，并创建系统层仿真模型。 (2) 在扩展ODE求解器进行机械系统运动表达的过程中，通过使用递推计算获得复杂度o(n)的相对坐标表达模型，并进一步论述了Lagrange乘子确定、数字漂移的多准则优化控制策略。对于冗余约束和一致性运动驱动问题，提出了基于QR分解策略以高效消除冗余约束，获得一致性的方法。最后，对具有离散拓扑变换的机械系统仿真实时性问题进行了讨论。 (3) 在虚拟样机动力学分析中，对施加的外部力／力矩的属性进行了分析，实现了力／力矩隐喻(metaphor)工具的直观定义，并基于多刚体动力学模型，提出了直观驱动的交互仿真方法。最后，通过对汽车发动机曲柄活塞部分的建模仿真实例论证了该方法的有效性，以及隐喻工具的直观性。 (4) 在机械系统虚拟样机运动仿真中，通常需要对单侧有摩擦非贯穿约束建立动力学模型，这一过程通常很困难。而基于传统刚体模型的非贯穿约束，更多还原

【Abstract】 During design phase, resorting to computer aided methodology ensures alternatives valid and subsystem integrity available. In the simplest condition, geometry data can generate fidelity effect draft via rendering. A verifiable 3D artifact will be produced by digital virtual prototyping emulating space size, interference and function. Not only geometry digital prototyping covers, but also a utility VR provides human-machine interface storing real complex 3D scenario, imaging in computer to be evaluated by observation. Besides navigation and interactive modification in VE, VR may take physical boundary condition such as interference, algorithm and motion into account. Furthermore, VP integrated information technology, real-time apperception and multi-channel interaction as well, including product design, performance analysis, manufacturability, assembly and service cycles so as to offer an intuitive 3D interface and a virtual test-bed for innovation.This paper will be motivated by above mentioned area, in the process of developing virtual design platform for product innovation, proposing as follow:(1) For VP kernel simulation model, a method based on CAD description established multi-disciplinary behavioral formulation was presented. Designer can generate joints from CAD , and connection of components by graph theory. As to software implementation, the behavior presentation about component and interface among them will be described based on port, the 3D mechanism linear graph deduced by CAD model expressing energetic flow, consistency between CAD and parametric components guaranteed by processing. Component encapsulated design, behavior and internal relationship between them, its instance inter-connected via port configuring and simulating complex system at system-level.(2) Extending ODE solver to describe mechanical system, we evolved it with relative coordinate by recursive computation, and ulteriorly determined multi-disciplinary optimization of control strategies for Lagrange multipliers and digital drift. For redundant constraint and consistent actuator, we can efficiently eliminate the former by QR decomposition to obtain the latter. Finally, the real-time simulation about discrete topology transformation of mechanical system performed in conclusion of this phase.(3) A naturally interactive simulation method for virtual prototyping dynamics analysis based on multi-body dynamics was presented by differentiating property of external force/torque and intuitively defining force/torque metaphor. In practice, this method would be very effective and unaffectedly with metaphor analyzing virtual prototyping as crank-piston mechanism in a car更多还原