Collaborative Research: Elements: Software: NSCI: Chrono-An open-source simulation platform for computational dynamics problems

合作研究：要素：软件：NSCI：Chrono-计算动力学问题的开源仿真平台

• 批准号: 1835727
• 负责人: Mario Medina
• 金额: $ 7.05万
• 依托单位: California State L A University Auxiliary Services Inc.
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1835727&HistoricalAwards=false
• 关键词: Collaborative; Research; Elements; Software; NSCI

This project seeks to augment modeling and solution methods employed by Chrono, an open-source computer simulation platform for multi-body dynamics (MBD) and fluid-solid interaction (FSI) problems. Chrono will be able to capture dynamics at various size and time scales spanning from millisecond (impact phenomena) to decades (geophysics). These performance levels open up new directions of research in several fields. Chrono is widely used and further developed by other users and has an active forum with more than 250 registered users currently. This project will enhance the richness of Chrono's modeling features, sound numerical solution foundation, and leverage of emerging hardware architectures to elevate this simulation capability to the status of ready-to-use, open-source, best-in-class computational dynamics platform. Chrono has been used by universities, national labs, and industry. Over the past two years, various groups have used Chrono in extraterrestrial applications, machine learning in robotics, image processing, pattern recognition and computer vision, mechanical watch design, architectural studies, autonomous vehicles, fluid-solid interaction applications, wind turbine dynamics, next generation space suit design, oil extraction and accident mitigation, hardware-in-the-loop simulation, etc. Finally, this project will engage high-school students from under-represented groups in a six-day residential camp run (now at its 12th edition) and will train a group of undergraduate students from California State University at University of Wisconsin-Madison through a new residential program that will introduce them to the use of Chrono in simulation-based robotics design.This project seeks to augment modeling and solution methods employed by Chrono, a BSD3 open-source simulation platform for multi-body dynamics (MBD) and fluid-solid interaction (FSI) problems. The software infrastructure enhancements in this project aim at sustaining teraflops-grade simulation of MBD and FSI systems with more than ten billion degrees of freedom; i.e., two to three orders of magnitude beyond conventional simulations today. In order to increase adoption and impact, the performance levels aimed at will be reached on budget/affordable hardware that leverages GPU computing. Chrono will be able to capture micro-, meso- and macro-scale dynamics on time scales spanning from millisecond (impact phenomena) to decades (geophysics). The intellectual merit of this project stems from the following key ideas: (i) with an eye towards the sunsetting of Moore's law, the software design solution embraces a scalable multi-GPU hardware layout poised to solve effectively large multi-physics problems; (ii) a hardware-aware software design paradigm, which aggressively reduces data storage and movement, will allow budget-conscious hardware systems to run billion-degree-of-freedom models, or, for models of similar size, accomplish a two orders of magnitude speedup when compared to the state of the art; (iii) a unified Lagrangian formulation for both solid and fluid dynamics is implemented in one software platform that can simulate complex multi-physics (coupled) problems; and (iv) Chrono promotes an alternative approach for handling friction and contact that revolves around the concept of differential variational inequality and thus avoids the small integration time step and numerical instability issues that hinder most of the existing many-body dynamics simulators. In relation to its educational and outreach initiatives, this project: (a) will be instrumental in establishing a new University of Wisconsin-Madison undergraduate course that introduces students to computing concepts subsequently refined in a graduate advanced computing class; (b) will promote the discipline of Computational Science and Computational Dynamics at high-school and undergraduate levels via two yearly residential summer programs for under-represented students; (c) will expand an advanced computing forum that facilitates technology transfer to industry and promotes Chrono adoption; and, (d) will strengthen ongoing collaborations that critically depend on Chrono in robotics, geomechanics, and soft-matter physics. Chrono is presently cloned on average 10 times every day, has been forked from its public repository by more than 150 parties, and has an active forum with more than 250 registered users. This project will enhance the richness of Chrono modeling features, improve its numerical solution foundation, and leverage emerging hardware architectures to elevate this simulation capability to the status of ready-to-use, open-source, best-in-class computational dynamics platform.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该项目旨在增强 Chrono 所采用的建模和解决方法，Chrono 是一个用于多体动力学 (MBD) 和流固相互作用 (FSI) 问题的开源计算机仿真平台。 Chrono 将能够捕获从毫秒（撞击现象）到数十年（地球物理学）的各种尺寸和时间尺度的动态。这些性能水平开辟了多个领域的新研究方向。 Chrono 被其他用户广泛使用和进一步开发，并拥有一个活跃的论坛，目前有超过 250 名注册用户。该项目将增强 Chrono 建模功能的丰富性、健全的数值解决方案基础，并利用新兴的硬件架构，将这种仿真能力提升到即用型、开源、一流的计算动力学平台的地位。 Chrono 已被大学、国家实验室和工业界使用。在过去的两年里，各个团体将 Chrono 用于外星应用、机器人机器学习、图像处理、模式识别和计算机视觉、机械手表设计、建筑研究、自动驾驶汽车、流固交互应用、风力涡轮机动力学、下一步一代太空服设计、石油开采和事故缓解、硬件在环模拟等。最后，该项目将让来自弱势群体的高中生参加为期六天的住宿营活动（现已是第 12 届）版）并将训练一个加州州立大学威斯康星大学麦迪逊分校的一群本科生通过一个新的住宿项目向他们介绍 Chrono 在基于仿真的机器人设计中的使用。该项目旨在增强 Chrono（BSD3）所采用的建模和解决方案方法用于多体动力学 (MBD) 和流固相互作用 (FSI) 问题的开源仿真平台。该项目中软件基础设施的增强旨在以超过百亿度的自由度维持 MBD 和 FSI 系统的万亿次浮点运算级仿真；即比当今的传统模拟高出两到三个数量级。为了提高采用率和影响力，将在利用 GPU 计算的预算/负担得起的硬件上达到目标性能水平。 Chrono 将能够在从毫秒（撞击现象）到数十年（地球物理学）的时间尺度上捕获微观、中观和宏观尺度的动态。该项目的智力价值源于以下关键想法：（i）着眼于摩尔定律的废止，软件设计解决方案采用了可扩展的多 GPU 硬件布局，旨在有效解决大型多物理场问题； (ii) 硬件感知软件设计范例，可大幅减少数据存储和移动，将允许注重预算的硬件系统运行十亿自由度模型，或者对于类似大小的模型，完成两个数量级的与现有技术相比，速度大幅提升； (iii) 在一个软件平台上实现固体和流体动力学的统一拉格朗日公式，可以模拟复杂的多物理场（耦合）问题； (iv) Chrono 提出了一种处理摩擦和接触的替代方法，该方法围绕微分变分不等式的概念，从而避免了阻碍大多数现有多体动力学模拟器的小积分时间步长和数值不稳定问题。就其教育和推广计划而言，该项目： (a) 将有助于建立威斯康星大学麦迪逊分校新的本科课程，向学生介绍随后在研究生高级计算课程中完善的计算概念； (b) 将通过每年两次为代表性不足的学生举办的暑期住宿项目，在高中和本科阶段推广计算科学和计算动力学学科； (c) 将扩大高级计算论坛，以促进技术向工业的转让并促进 Chrono 的采用； (d) 将加强在机器人学、地质力学和软物质物理学方面严重依赖 Chrono 的持续合作。 Chrono 目前平均每天被克隆 10 次，已被 150 多个团体从其公共存储库分叉，并拥有一个拥有超过 250 个注册用户的活跃论坛。该项目将增强 Chrono 建模功能的丰富性，改善其数值解决方案基础，并利用新兴的硬件架构将这种仿真能力提升到即用型、开源、一流的计算动力学平台的地位。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。