A Foot Resistive Force Model for Legged Locomotion on Muddy Terrains

TL;DR

This paper introduces a resistive force model for legged robot foot interactions with muddy terrains, enabling improved locomotion and energy efficiency through a novel morphing foot design.

Contribution

The paper presents a new resistive force model capturing mud rheology and uses it to design a morphing robotic foot for better mobility on muddy terrains.

Findings

The force model accurately predicts resistive forces in mud.

The morphing foot improves locomotion mobility in mud.

The design enhances energy efficiency during mud traversal.

Abstract

Legged robots face significant challenges in moving and navigating on deformable and highly yielding terrain such as mud. We present a resistive force model for legged foot-mud interactions. The model captures rheological behaviors such as visco-elasticity, thixotropy of the mud suspension and retractive suction. One attractive property of this new model lies in its effective, uniform formulation to provide underlying physical interpretation and accurate resistive force predictions. We further take advantage of the resistive force model to design a new morphing robotic foot for effective and efficient legged locomotion. We conduct extensive experiments to validate the force model, and the results demonstrate that the morphing foot enhances not only the locomotion mobility but also energy-efficiency of walking in mud. The new resistive force model can be further used to develop data-driven simulation and locomotion control of legged robots on muddy terrains.