arXiv AI

Mind the Phase: Effective Rank and Representation Health in Legged Locomotion

The paper investigates how reinforcement‑learning policies for legged robots encode gait information by examining the effective rank of the policy Jacobian conditioned on gait phase. It finds that common architectural features such as layer normalization and residual connections allocate more representational capacity to swing than stance, a pattern absent in vanilla MLPs. Leveraging these insights, the authors propose a simple recipe that improves sim‑to‑real transfer, reducing joint jitter on a physical Spot robot by roughly three‑fold.

arXiv AI
Jul 23

PGTT: Phase-Guided Terrain Traversal for Perceptive Legged Locomotion

arXiv:2510. 18348v2 Announce Type: replace-cross Abstract: State-of-the-art perceptive Reinforcement Learning controllers for legged robots typically either (i) impose oscillator-or IK-based gait priors that constrain the action space, bias policy optimization, and limit adaptability across robot morphologies, or (ii) operate "blind," making them unable to anticipate hind-leg terrain and brittle to observation noise.

By Alexandros Ntagkas, Chairi Kiourt, Konstantinos Chatzilygeroudis
arXiv Machine Learning
Jun 16

LoComposition: Terrain-Adaptive Energy-Efficient Quadruped Locomotion without Gait Priors

arXiv:2606. 15896v1 Announce Type: cross Abstract: Learning-based quadrupedal locomotion typically relies on complex reward formulations that entangle task specification, operational limits, gait preference, and terrain adaptation within a single optimization objective.

By Loukas Kordos, Leonard T. Franz, Simon Rappenecker, Oliver Hausdoerfer, Angela P. Schoellig, Pavel Kolev, Georg Martius
arXiv Machine Learning
Jul 31

REFINE-DP: Diffusion Policy Fine-tuning for Humanoid Loco-manipulation via Reinforcement Learning

arXiv:2603. 13707v3 Announce Type: replace-cross Abstract: Humanoid loco-manipulation requires coordinated task-space motion planning with stable loco-manipulation command tracking under complex robot-environment dynamics and long-horizon tasks.

By Zhaoyuan Gu, Yipu Chen, Zimeng Chai, Alfred Cueva, Thong Nguyen, Yifan Wu, Huishu Xue, Minji Kim, Isaac Legene, Fukang Liu, KyoungMok Kim, Ayan Barula, Yongxin Chen, Ye Zhao
arXiv AI
Jul 2

Learning Gait-Aware Quadruped Locomotion with Temporal Logic Specifications

arXiv:2607. 00442v1 Announce Type: cross Abstract: Reinforcement learning (RL) for quadruped locomotion commonly depends on fixed, hand-crafted, and Markovian reward functions that limit both interpretability of learned policies and lack explicit control over gait behaviors.

By Merve Atasever, Cagan Bakirci, Alfredo Reina Corona, Keyan Azbijari, Jyotirmoy V. Deshmukh
arXiv Machine Learning
Jun 5

OLIVE: Online Low-Rank Incremental Learning for Efficient Adaptive Exoskeletons

arXiv:2606. 05234v1 Announce Type: cross Abstract: Wearable exoskeleton systems hold promise for restoring mobility in individuals with physical impairments, yet most existing controllers rely on static gait policies that lack the ability to adapt to dynamic real-world environments or individual user characteristics.

By Dong Liu, Yanxuan Yu, Ben Lengerich, Tony Geng, Ying Nian Wu