CHS: Small: Fast simulation of geometrically complex multibody systems in contact and self-contact

CHS：小型：快速模拟接触和自接触的几何复杂多体系统

• 批准号: 1422869
• 负责人: Jernej Barbic
• 金额: $ 48.42万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1422869&HistoricalAwards=false
• 关键词: CHS; Small; Fast; simulation; geometrically

The ability to simulate complex machinery in contact is broadly applicable to engineering practice. It can be used for virtual training, say in the operation of heavy machinery. Perhaps most importantly, it can be used to assemble and test complex mechanical structures in virtual reality (using a human-computer interface that includes haptic feedback). Such virtual prototyping, as it is commonly called, greatly shortens design cycles, decreases errors, improves product safety and saves millions of dollars in R&D costs. Applications can be found anywhere a complex structure must be designed and manufactured out of many component parts: airplanes, cars, trains, spaceships, power plants, buildings, tools, heavy equipment, etc. In this project the PI will develop computationally efficient collision detection and contact resolution methods that can accommodate complex systems consisting of many objects that are connected by joints and undergoing contact and self-contact. His goal is to devise algorithms that are sufficiently fast to accommodate high update rates (1,000 simulation steps per second for haptics, or more), and that scale to complex real-world mechanisms typically represented by millions of triangles, such as an internal combustion engine or an entire car engine compartment, an airplane landing gear or airplane doors, or excavator machines. Furthermore, whereas previous fast successful industrial penalty-based methods have typically been limited to pairs of objects in contact, in this research the PI's objective is to deal with more complex and realistic situations including rigid objects, joints, friction and self-contact.Fast simulation of multi-body systems in contact is challenging due to the severe computational and stability requirements imposed by complex geometry. Such simulations frequently involve distributed contact, that is to say contact involving many collision sites of varying surface areas and normal orientations that change rapidly over time. Because it is challenging for constraint-based methods to resolve such contact stably at high update rates, the Principal Investigator will exploit industry-proven penalty methods between points and implicit functions (distance fields or voxmaps), and he will extend the approach, which has to date been limited to pairs of objects in contact, to accommodate N = 2 objects in arbitrary contact, as well as objects connected with joints and undergoing active control. The technical challenges include how to stably resolve and time-step distributed contact between N = 2 objects, how to stably simulate and render 6-DOF distributed contact in the presence of constraints (joints), and how to handle self-contact and incorporate friction, all the while maintaining high update rates (or gracefully degrading them in case of extreme contact). Because the Principal Investigator's preliminary experience suggests that the discrete nature of current algorithms is an important limitation in practice, he will also investigate continuous collision detection between points and distance fields. Project outcomes will be transitioned to engineering practice via the PI's ongoing collaborations with a number of industrical leaders in high-tech virtual prototyping, and will advance the state of the art in computer graphics, haptics, robotics and virtual reality.

模拟接触中复杂机械的能力广泛适用于工程实践。 它可以用于虚拟培训，例如重型机械的操作。 也许最重要的是，它可用于在虚拟现实中组装和测试复杂的机械结构（使用包括触觉反馈的人类计算机界面）。 这种虚拟原型制作通常被称为大大缩短设计周期，可减少错误，改善产品安全性并节省数百万美元的研发成本。 可以在任何组件中设计和制造的复杂结构的任何地方都可以找到应用程序：飞机，汽车，火车，太空飞船，发电厂，建筑物，工具，重型设备等。 他的目标是设计足够快的算法以适应高更新速率（触觉或更多的触觉每秒模拟步骤），并将其扩展到复杂的现实世界机制，通常由数百万个三角形代表，例如内燃烧引擎或整个汽车发动机，或整个汽车发动机，一个飞机登陆齿轮或飞机齿轮或飞机式机制或Excececececemines或Excececececeminess或Excecececececeminess或Excecececececeminess或Excececececececeartor或Excececececececeminess或Excececececececemine或Excececececececemines或Excececececececeartor的Machines Machines。 此外，尽管以前的快速成功基于工业罚款的方法通常仅限于接触的对象，但在这项研究中，PI的目标是处理更复杂和现实的情况，包括刚性对象，摩擦，摩擦和自我键盘的固定型，触点中多体系统的仿真造成了严重的计算和稳定性需求，因此具有挑战性的计算和稳定性。这样的模拟经常涉及分布式接触，也就是说，涉及各种表面积和正常方向的许多碰撞部位随着时间的流逝而迅速变化的接触。 由于基于约束的方法以高度更新速率解决此类联系是充满挑战的，因此主要研究者将利用要点和隐式功能之间的行业预处理的惩罚方法（距离字段或VoxMaps），他将扩展该方法，到目前 技术挑战包括如何在n = 2个对象之间稳定解决和时间键分布式接触，如何在存在约束（关节）的情况下稳定模拟和渲染6-DOF分布式接触，以及如何处理自我接触并结合摩擦，同时保持高更新速率（或在极端接触中优雅地降解它们）。 由于主要研究者的初步经验表明，当前算法的离散性质是实践中的重要限制，因此他还将研究点和距离领域之间的连续碰撞检测。 项目成果将通过PI在高科技虚拟原型制作中与许多工业领导者进行的持续合作过渡到工程实践，并将在计算机图形，触觉，机器人和虚拟现实中推进最新技术。