From Impact to Insight: Dynamics-Aware Proprioceptive Terrain Sensing on Granular Media

This paper presents a physics-based framework for dynamic terrain characterization using proprioceptive sensing during high-speed hopping on granular media. The study reveals that quasi-static assumptions lead to significant discrepancies in terrain property estimation, particularly during touchdown and stiffness transitions. Acceleration-dependent added-mass effects, associated with grain entrainment, dominate transient force responses. The authors integrate force decomposition with a momentum-observer-based estimator and introduce acceleration-aware weighted regression to improve terrain inference accuracy.