Data-Driven Terramechanics Approach Towards a Realistic Real-Time Simulator for Lunar Rovers

TL;DR

The paper tackles the challenge of achieving both visual realism and physically accurate wheel–terrain interaction in real-time lunar rover simulation. It introduces a data-driven terramechanics framework that regresses wheel slip and sinkage from field and DEM-derived data, then integrates these models into the OmniLRS-based real-time simulator to drive slip-adjusted velocities and compliant contact-based sinkage. Terrain deformation and enhanced wheel-trace rendering are added to produce believable soil interaction while maintaining real-time performance. Validation against field tests shows sub-0.25% errors in slip and sub-0.3 mm errors in sinkage, with robust behavior on slopes up to 20 degrees. The approach enables practical use in mobility analysis, mission planning, and digital twin applications, with future work aimed at lunar regolith fidelity and extension to legged platforms.

Abstract

High-fidelity simulators for the lunar surface provide a digital environment for extensive testing of rover operations and mission planning. However, current simulators focus on either visual realism or physical accuracy, which limits their capability to replicate lunar conditions comprehensively. This work addresses that gap by combining high visual fidelity with realistic terrain interaction for a realistic representation of rovers on the lunar surface. Because direct simulation of wheel-soil interactions is computationally expensive, a data-driven approach was adopted, using regression models for slip and sinkage from data collected in both full-rover and single-wheel experiments and simulations. The resulting regression-based terramechanics model accurately reproduced steady-state and dynamic slip, as well as sinkage behavior, on flat terrain and slopes up to 20 degrees, with validation against field test results. Additionally, improvements were made to enhance the realism of terrain deformation and wheel trace visualization. This method supports real-time applications that require physically plausible terrain response alongside high visual fidelity.

Figures (9)

• Figure 1: (a) Data-driven terramechanics model for recreating realistic wheel slip, sinkage and wheel traces inside the real-time lunar surface simulator OmniLRS. (b) A rover makes physically reasonable wheel traces in our simulator. (c) Rigid and soft contacts are treated respectively.
• Figure 2: Architecture of the proposed method.
• Figure 3: Experimental setup of the data acquisition field test (top) and two representative snaps of slope climbing (bottom-left) and acceleration (bottom-right).
• Figure 4: Single wheel testbed (left) EX1_grouser and DEM simulation (right) Hurrell_2.
• Figure 5: Rover illustrated with visual wheel geometry (left) and physics wheel geometry (right).