Paper: “Gait Transitions in Load-Pulling Quadrupeds: Insights from Sled Dogs and a Minimal SLIP Model”
Authors: Jiayu Ding, Benjamin Seleb, Heather Jay Huson , Saad Bhamla, and Zhenyu Gan
arXiv preprint, 2025
This research investigates how sled dogs dynamically transition between galloping gaits when pulling heavy loads at high speed. Using high-speed video, force sensors, and data loggers in field experiments, the study reveals that sled dogs frequently switch between rotary and transverse galloping gaits over just a few strides, even when speed, stride duration, and terrain remain constant. These observations demonstrate a surprising degree of locomotor multistability and suggest that adaptive gait transitions are an important part of high-performance load-pulling in working dogs.
To explain these transitions, the authors developed a physics-based quadrupedal Spring-Loaded Inverted Pendulum (SLIP) model with hybrid dynamics and a tugline-coupled load. The model incorporates limb asymmetry and supports stride-specific modulation of swing-leg stiffness to replicate the experimentally observed footfall patterns and force trajectories. Through trajectory optimization, the model successfully reproduces both steady-state galloping gaits and stride-to-stride transitions, revealing that targeted changes in hindlimb or forelimb swing stiffness alone can drive rapid switching between gallop types.
This study provides a new biomechanical perspective on animal draft locomotion, offering the first dynamical model that captures both detailed stride mechanics and spontaneous gait transitions under load. The results advance our understanding of the mechanics and control of working quadrupeds and suggest new strategies for designing adaptive legged robots capable of efficient gait switching while hauling loads.
Reference
@article{ding2025gait,
title={Gait Transitions in Load-Pulling Quadrupeds: Insights from Sled Dogs and a Minimal SLIP Model},
author={Ding, Jiayu and Gan, Zhenyu and Seleb, Benjamin and Bhamla, Saad},
journal={arXiv preprint arXiv:2507.14727},
year={2025},
url={https://arxiv.org/abs/2507.14727}
}