A Physics-Based Continuum Model for Versatile, Scalable, and Fast Terramechanics Simulation

TL;DR

This paper introduces Chrono::CRM, a physics-based, scalable, and GPU-accelerated terramechanics simulation model capable of handling complex terrain interactions and deformable objects at large scales with high efficiency.

Contribution

The paper presents a novel physics-based terramechanics model built on Chrono's SPH framework, enabling large-scale, high-fidelity simulations with validation against experimental and high-fidelity DEM data.

Findings

Chrono::CRM accurately matches experimental terramechanics data.

The model achieves near real-time performance for large-scale terrain simulations.

It can simulate terrain stretches up to 10 km with 100 million particles.

Abstract

This paper discusses Chrono's Continuous Representation Model (called herein Chrono::CRM), a general-purpose, scalable, and efficient simulation solution for terramechanics problems. Built on Chrono's Smoothed Particle Hydrodynamics (SPH) framework, Chrono::CRM moves beyond semi-empirical terramechanics approaches, e.g., Bekker-Wong/Janosi-Hanamoto, to provide a physics-based model able to address complex tasks such as digging, grading, as well as interaction with deformable wheels and complex grouser/lug patterns. The terramechanics model is versatile in that it allows the terrain to interact with both rigid and flexible implements simulated via the Chrono dynamics engine. We validate Chrono::CRM against experimental data from three physical tests, including one involving NASA's MGRU3 rover. In addition, the simulator is benchmarked against a high-fidelity Discrete Element Method (DEM) simulation of a digging scenario involving the Regolith Advanced Surface Systems Operations Robot (RASSOR). Being GPU-accelerated, Chrono::CRM achieves computational efficiency comparable to that of semi-empirical simulation approaches for terramechanics problems. Through an ``active domains'' implementation, Chrono::CRM can handle terrain stretches up to 10 km long with 100 million SPH particles at near interactive rates, making high-fidelity off-road simulations at large scales feasible. As a component of the Chrono package, the CRM model is open source and released under a BSD-3 license. All models and simulations used in this contribution are available in a public GitHub repository for reproducibility studies and further research.