Oral Session
Oral Session 5C: Geometry and Robotics
AT-VLA: Adaptive Tactile Injection for Enhanced Feedback Reaction in Vision-Language-Action Models
Xiaoqi Li ⋅ Muhe Cai ⋅ Jiadong Xu ⋅ Juan Zhu ⋅ Hongwei Fan ⋅ Yan Shen ⋅ Guangrui Ren ⋅ Hao Dong
Vision-Language-Action (VLA) models have significantly advanced robotic agents capable of executing diverse tasks; however, they remain limited in contact-rich manipulation scenarios that require precise physical interactions. To address this limitation, recent studies have attempted to incorporate tactile signals during downstream tasks, enabling pretrained VLAs to interpret tactile feedback. Nevertheless, introducing new modalities during finetuning, which are rarely present in the pretrain stage, may disrupt the pretrained capabilities of VLAs. In addition, the inherently slow inference speed of VLAs hampers real-time responsiveness and limits the effective utilization of tactile feedback for action adjustment.To overcome these challenges, we propose Adaptive Tactile Vision-Language-Action (AT-VLA), which introduces a novel Adaptive Tactile Injection mechanism. This mechanism dynamically determines the appropriate timing and locations for tactile injection, incorporating only when it significantly contributes to action generation, thereby minimizing interference with pretrained representations.Furthermore, to enable rapid and accurate tactile responses, we propose a Tactile Reaction Dual-Stream mechanism, which decouples sensory processing into a slow visual-language stream for low-frequency perceptual reasoning and a fast tactile control stream for high-frequency physical interaction understanding, achieving real-time close-loop responses within 0.04 s.Real-world experiments thoroughly validate the effectiveness of AT-VLA in contact-rich manipulation tasks.
Learning Diffeomorphism for Medical Image Registration with Time-Embedded Architectures Using Semigroup Regularization
Mohammadjavad Matinkia ⋅ Nilanjan Ray
Diffeomorphic image registration (DIR) seeks topology-preserving transformations and is fundamental in medical imaging. Existing DIR methods rely on integration schemes (e.g., scaling-and-squaring) and multiple regularizers to enforce invertibility. We introduce SGDIR, a continuous-time registration framework, parameterized by known time-embedded backbones, that models diffeomorphisms using only a single semigroup-based regularization, eliminating explicit integration and auxiliary constraints. We mathematically prove that this formulation directly learns the flow of an underlying ODE, inherently enforcing inverse and cycle consistencies. We evaluate on eight 2D and 3D MR and CT datasets. Under strict semigroup enforcement, our model achieves near-perfect diffeomorphism (near-zero folding) and significantly outperforms existing diffeomorphic methods, while remaining competitive with leading non-diffeomorphic deformable models. When the regularization is relaxed, the same architecture functions as a deformable method and substantially surpasses state-of-the-art non-diffeomorphic approaches in registration accuracy. These results demonstrate that continuous-time deformation modeling, guided solely by our semigroup-based regularization, yields a unified framework capable of both rigorously diffeomorphic mapping and state-of-the-art deformable registration.
QuadSync: Quadrifocal Tensor Synchronization via Tucker Decomposition
Daniel Miao ⋅ Gilad Lerman ⋅ Joe Kileel
In structure from motion, quadrifocal tensors capture more information than their pairwise counterparts (essential matrices), yet they have often been thought of as impractical and only of theoretical interest. In this work, we challenge such beliefs by providing a new framework to recover $n$ cameras from the corresponding collection of quadrifocal tensors. We form the block quadrifocal tensor and show that it admits a Tucker decomposition whose factor matrices are the stacked camera matrices, and which thus has a multilinear rank of (4,4,4,4) independent of $n$. We develop the first synchronization algorithm for quadrifocal tensors, using Tucker decomposition, alternating direction method of multipliers, and iteratively reweighted least squares. We further establish relationships between the block quadrifocal, trifocal, and bifocal tensors, and introduce an algorithm that jointly synchronizes these three entities. Numerical experiments demonstrate the effectiveness of our methods on modern datasets, indicating the potential and importance of using higher-order information in synchronization.
SocialNav: Training Human-Inspired Foundation Model for Socially-Aware Embodied Navigation
Ziyi Chen ⋅ Yingnan Guo ⋅ Zedong Chu ⋅ Minghua Luo ⋅ Yanfen Shen ⋅ Mingchao Sun ⋅ Junjun Hu ⋅ Shichao Xie ⋅ Yang Kuan ⋅ Pei Shi ⋅ Zhining Gu ⋅ Lu Liu ⋅ Honglin Han ⋅ Xiaolong Wu ⋅ Mu Xu ⋅ Yu Zhang
Embodied navigation that adheres to social norms remains an open research challenge. Our SocialNav is a foundational model for socially-aware navigation with a hierarchical "brain-action" architecture, capable of understanding high-level social norms and generating low-level, socially compliant trajectories. To enable such dual capabilities, we construct the SocNav Dataset, a large-scale collection of 7 million samples, comprising (1) a Cognitive Activation Dataset providing social reasoning signals such as chain-of-thought explanations and social traversability prediction, and (2) an Expert Trajectories Pyramid aggregating diverse navigation demonstrations from internet videos, simulated environments, and real-world robots. A multi-stage training pipeline is proposed to gradually inject and refine navigation intelligence: we first inject general navigation skills and social norms understanding into the model via imitation learning, and then refine such skills through a deliberately designed Socially-Aware FlowExploration GRPO (SAFE-GRPO), the first flow-based reinforcement learning framework for embodied navigation that explicitly rewards socially compliant behaviors. SocialNav achieves +38% success rate and +46% social compliance rate compared to the state-of-the-art method, demonstrating strong gains in both navigation performance and social compliance. Data and code will be made publicly available.
Structural Action Transformer for 3D Dexterous Manipulation
Xiaohan Lei ⋅ Min Wang ⋅ Bohong Weng ⋅ Wengang Zhou ⋅ Houqiang Li
Achieving human-level dexterity in robots via imitation learning from heterogeneous datasets is hindered by the challenge of cross-embodiment skill transfer, particularly for high-DoF robotic hands. Existing methods, often relying on 2D observations and temporal-centric action representation, struggle to capture 3D spatial relations and fail to handle embodiment heterogeneity.This paper proposes the Structural Action Transformer (SAT), a new 3D dexterous manipulation policy that challenges this paradigm by introducing a structural-centric perspective. We reframe each action chunk not as a temporal sequence, but as a variable-length, unordered sequence of joint-wise trajectories.This structural formulation allows a Transformer to natively handle heterogeneous embodiments, treating the joint count as a variable sequence length.To encode structural priors and resolve ambiguity, we introduce an Embodied Joint Codebook that embeds each joint's functional role and kinematic properties.Our model learns to generate these trajectories from 3D point clouds via a continuous-time flow matching objective.We validate our approach by pre-training on large-scale heterogeneous datasets and fine-tuning on simulation and real-world dexterous manipulation tasks.Our method consistently outperforms all baselines, demonstrating superior sample efficiency and effective cross-embodiment skill transfer.This structural-centric representation offers a new path toward scaling policies for high-DoF, heterogeneous manipulators.
TESO: Online Tracking of Essential Matrix by Stochastic Optimization
Jaroslav Moravec ⋅ Radim Sara ⋅ Akihiro Sugimoto
Reliable perception of autonomous systems relies on fusion of data from multiple sensors, which requires maintaining accurate geometric calibration during operation. This work aims to track the drift of the calibration parameters caused by mechanical stress, thermal effects, or minor accidents. We focus on five parameters of the essential matrix and propose TESO, whose core mechanisms are: 1) a robust loss function based on kernel correlation over tentative correspondences instead of robust matching and estimators, 2) an adaptive online stochastic optimization on the essential manifold. Both contribute to reduced CPU and memory requirements. TESO relies on a few hyperparameters and eliminates the need for data-driven training, enabling use in resource-constrained online perception systems. We evaluated TESO based on the geometric precision of the tracked extrinsic parameters, the rectification quality, and the stereo depth consistency with respect to a 3D LiDAR. In the large-scale MAN TruckScenes dataset, TESO tracks drift with 0.12° precision in the rotation around Y, which is critical for stereo accuracy, while the other two rotation angles are tracked with five times better precision. Sequences with simulated drift are tracked with similar precision as the no-drift ones, suggesting that the tracker is unbiased. Applied to the KITTI dataset, TESO reported systematic inconsistencies in extrinsic parameters across all stereo pairs, confirming observations made by other authors. We verify that these errors were partly caused by intrinsic decalibration, which manifested in the contradictory performance of two metrics: The epipolar error and the depth estimation accuracy. With corrected calibration parameters, TESO improved its rotation precision around the hardest Y-axis by approximately twentyfold, reaching 0.025°. In the depth estimation, there was a fiftyfold improvement. Despite its lightweight nature, we show that the combination of SIFT features and the proposed TESO loss function achieves accuracy comparable to published single-frame methods that rely on neural network models.