The soil contact model (SCM) is widely used in practice for off-road wheeled vehicle mobility studies when simulation speed is important and highly accurate results are not a main concern. In practice, the SCM parameters are obtained via a bevameter test, which requires a complex apparatus and experimental procedure. Here, we advance the idea of running a virtual bevameter test using a high-fidelity terramechanics simulation. The latter employs the “continuous representation model” (CRM), which regards the deformable terrain as an elasto-plastic continuum that is spatially discretized using the smoothed particle hydrodynamics method. The approach embraced is as follows: a virtual bevameter test is run in simulation using CRM terrain to generate “ground truth” data; in a Bayesian framework, this data is subsequently used to calibrate the SCM terrain. We show that (i) the resulting SCM terrain, while leading to fast terramechanics simulations, serves as a good proxy for the more complex CRM terrain; and (ii) the SCM-over-CRM simulation speedup is roughly one order of magnitude. These conclusions are reached in conjunction with two tests: a single wheel test, and a full rover simulation. The SCM and CRM simulations are run in the open-source software Chrono. The calibration is performed using PyMC, which is a Python package that interactively communicates with Chrono to calibrate SCM. The models and scripts used in this contribution are available as open source for unfettered use and distribution in a public repository.

中文翻译：

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使用更高保真度模型、贝叶斯推理和虚拟贝瓦计测试来校准快速地形力学模型

当模拟速度很重要且高精度结果不是主要关注点时，土壤接触模型 (SCM) 广泛应用于越野轮式车辆移动性研究的实践中。在实践中，SCM参数是通过波瓦计测试获得的，这需要复杂的设备和实验过程。在这里，我们提出了使用高保真地形力学模拟运行虚拟波瓦仪测试的想法。后者采用“连续表示模型”（CRM），将可变形地形视为弹塑性连续体，并使用平滑粒子流体动力学方法进行空间离散。采用的方法如下：使用 CRM 地形模拟运行虚拟波瓦计测试，生成“地面实况”数据；在贝叶斯框架中，该数据随后用于校准 SCM 地形。我们表明 (i) 由此产生的 SCM 地形在实现快速地形力学模拟的同时，可以作为更复杂的 CRM 地形的良好代理； (ii) SCM-over-CRM 模拟加速大约是一个数量级。这些结论是结合两项测试得出的：单轮测试和完整的流动站模拟。 SCM 和 CRM 模拟在开源软件 Chrono 中运行。校准是使用 PyMC 执行的，PyMC 是一个与 Chrono 交互通信以校准 SCM 的 Python 包。本贡献中使用的模型和脚本可作为开源代码在公共存储库中不受限制地使用和分发。