Bipedal-Walking-Dynamics Model on Granular Terrains

2026-04-13

AI Summary

This study addresses the challenge of unstable locomotion and increased energy consumption in bipedal robots walking on granular media such as sand, where foot sinking and slipping significantly degrade performance. To overcome this, the work proposes a novel bipedal walking dynamics model that explicitly incorporates foot sinking and slipping as three additional degrees of freedom. Coupled with a dynamic foot–ground interaction module, the model enables real-time computation of ground reaction forces, thereby accurately capturing the kinematic and dynamic characteristics of locomotion on granular terrain. Experimental validation demonstrates that the model precisely predicts gait profiles, penetration depth, and ground reaction forces on sandy surfaces, offering a critical theoretical foundation for efficient motion control and energy optimization in legged locomotion over deformable substrates.

Technology Category

• Intelligent Robots: Motion and Path Planning
• Planning, Routing, and Scheduling: Model-Based Reasoning
• Natural Language Processing: Language Grounding & Multi-modal NLP

Application Category

• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs
• User Modeling, Personalization and Recommendation: User modeling and simulation for interactive and conversational systems
• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments

Abstract

Bipeds have demonstrated high agility and mobility in unstructured environments such as sand. The yielding of such granular media brings significant sinkage and slip of the bipedal feet, leading to uncertainty and instability of walking locomotion. We present a new dynamics-modeling approach to capture and predict bipedal-walking locomotion on granular media. A dynamic foot-terrain interaction model is integrated to compute the ground reaction force (GRF). The proposed granular dynamic model has three additional degree-of-freedom (DoF) to estimate foot sinkage and slip that are critical to capturing robot-walking kinematics and kinetics such as cost of transport (CoT). Using the new model, we analyze bipedal kinetics, CoT, and foot-terrain rolling and intrusion affects. Experiments are conducted using a biped robotic walker on sand to validate the proposed dynamic model with robot-gait profiles, media-intrusion prediction, and GRF estimations. This new dynamics model can further serve as an enabling tool for locomotion control and optimization of bipedal robots to efficiently walk on granular terrains.

Problem

• bipedal walking
• granular terrains
• foot sinkage
• slip
• locomotion instability

Innovation

• bipedal walking
• granular terrain
• foot-terrain interaction
• ground reaction force
• sinkage and slip