Real-Time Simulation of Ground Vehicles on Deformable Terrain
Real-Time Simulation of Ground Vehicles on Deformable Terrain
复制标题
地面车辆在变形地形上的实时仿真
DOI：
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
Zhenhao Zhou
中科院分区：
文献类型：
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作者：
R. Serban;Jay Taves;Zhenhao Zhou
基于刚体和柔性多体动力学的复杂建模和仿真是当今车辆系统设计和分析的标准程序，并被广泛应用于道路驾驶。陆地轮式和履带式车辆以及用于外太空探索的轮式和腿式机器人和漫游车的越野驾驶带来了额外的建模和仿真挑战，其中主要的挑战是车辆与地形的相互作用、可变形地形的建模以及一般的地形力学。
建模可变形地形的技术跨越了整个范围，在复杂性、表示精度和随后的计算工作量方面有所不同。尽管全分辨颗粒动力学、颗粒材料的连续介质建模或有限元等公式可以提供高水平的精度，但它们这样做的成本很高，即使在实施利用并行计算和/或硬件加速器时也是如此。实时或比实时更快的地面力学是非常需要的能力(在自动车辆和机器人系统的训练等应用中)或关键能力(在人在环中或硬件在环中的应用中)。
在德国航空航天中心发展的土壤接触模型(SCM)的基础上，我们提出了一个实时可变形土壤模型，该模型可以看作是Bekker-Wong和Janosi-Hanamoto的土壤与任意三维形状和任意接触块相互作用的半经验模型的推广。这种SCM实现可以在开源的多物理包Chrono中获得，同时还可以使用计算密集型的可变形土壤表示法。描述了Chrono SCM模型的总体实现和特点、高效的底层数据结构、当前的多核并行方面及其在可变形地形上的多车辆并发仿真的可伸缩性。
Sophisticated modeling and simulation, based on rigid and flexible multibody dynamics, are nowadays a standard procedure in the design and analysis of vehicle systems and are widely adopted for on-road driving. Off-road driving for both terrestrial wheeled and tracked vehicles, as well as wheeled and legged robots and rovers for extra-terrestrial exploration pose additional modeling and simulation challenges, a primary one being that of the vehicle-terrain interaction, modeling of deformable terrain, and terramechanics in general.
Techniques for modeling deformable terrain span an entire range varying in complexity, representation accuracy, and ensuing computational effort. While formulations such as fully-resolved granular dynamics, continuum modeling of granular material, or finite element can provide a high level of accuracy, they do so at a significant cost, even when the implementation leverages parallel computing and/or hardware accelerators. Real-time or faster than real-time terramechanics is a highly desired capability (in applications such as training of autonomous vehicles and robotic systems) or critical capability (in applications such as human-in-the-loop or hardware-in-the-loop).
We present a real-time capable deformable soil implementation, extended from the Soil Contact Model (SCM) developed at the German Aerospace Center which in turn can be viewed as a generalization of the Bekker-Wong and Janosi-Hanamoto semi-empirical models for soil interaction with arbitrary three-dimensional shapes and arbitrary contact patches. This SCM implementation is available, alongside more computationally intensive deformable soil representations, in the open-source multi-physics package Chrono. We describe the overall implementation and the features of the Chrono SCM model, the efficient underlying data structures, the current multi-core parallelization aspects, and its scalability properties for concurrent simulation of multiple vehicles on deformable terrain.