Abstract
This paper presents a foundational study on the design, modeling, and control of a novel robotic limb that generates overconstrained locomotion. By utilizing a Bennett linkage for motion generation, the limb enables parametric reconfiguration between reptile- and mammal-inspired morphologies within a single quadrupedal platform. While the family of overconstrained linkages has solid theoretical foundations in spatial kinematics, it remains underexplored in dynamic robotics. This work establishes the morphological and performance advantages of Overconstrained Robotic Limbs (ORLs), which can transform into prevailing planar limbs. We develop a complete kinematic and dynamic model of the ORL and apply Model Predictive Control (MPC) to validate its performance. Hardware experiments on a single-limb prototype validate the core mechanical design and actuation principles. Furthermore, extensive high-fidelity simulations of the complete quadruped confirm the efficacy of our control framework for a range of dynamic locomotion tasks over challenging terrains. Besides the clear advantage in lateral mobility, our comparative analysis reveals the ORL's superior energy efficiency over planar limbs when considering varying foothold distances and speeds. From an evolutionary biology perspective, these findings provide a quantitative insight into the distinctive biomechanical trade-offs in limb design, presenting the first comprehensive analysis of how ORLs outperform planar designs in simulated dynamic locomotion.
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@online{Sun2025OverconstrainedLocomotion,
title = {Overconstrained Locomotion},
author = {Haoran Sun and Bangchao Huang and Zishang Zhang and Junwei Lv and Guangyi Huang and Jiayi Yin and Shihao Feng and Ronghan Xu and Guojing Huang and Nuofan Qiu and Hua Chen and Wei Zhang and Fang Wan and Jia Pan and Chaoyang Song},
url = {https://github.com/ancorasir/OverconstrainedLocomotion},
year = {2025},
date = {2025-10-01},
abstract = {This paper presents a foundational study on the design, modeling, and control of a novel robotic limb that generates overconstrained locomotion. By utilizing a Bennett linkage for motion generation, the limb enables parametric reconfiguration between reptile- and mammal-inspired morphologies within a single quadrupedal platform. While the family of overconstrained linkages has solid theoretical foundations in spatial kinematics, it remains underexplored in dynamic robotics. This work establishes the morphological and performance advantages of Overconstrained Robotic Limbs (ORLs), which can transform into prevailing planar limbs. We develop a complete kinematic and dynamic model of the ORL and apply Model Predictive Control (MPC) to validate its performance. Hardware experiments on a single-limb prototype validate the core mechanical design and actuation principles. Furthermore, extensive high-fidelity simulations of the complete quadruped confirm the efficacy of our control framework for a range of dynamic locomotion tasks over challenging terrains. Besides the clear advantage in lateral mobility, our comparative analysis reveals the ORL's superior energy efficiency over planar limbs when considering varying foothold distances and speeds. From an evolutionary biology perspective, these findings provide a quantitative insight into the distinctive biomechanical trade-offs in limb design, presenting the first comprehensive analysis of how ORLs outperform planar designs in simulated dynamic locomotion.},
note = {Submitted to the Special Collection for ISRR24 in the International Journal of Robotics Research},
keywords = {Authorship - Corresponding, Status - Under Review},
pubstate = {forthcoming},
tppubtype = {online}
}
