IVRA: Improving Visual-Token Relations for Robot Action Policy with Training-Free Hint-Based Guidance

Fuente: arXiv
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Hauptverfasser: Park, Jongwoo, Ranasinghe, Kanchana, Jang, Jinhyeok, Mata, Cristina, Jang, Yoo Sung, Ryoo, Michael S
Format: Preprint
Veröffentlicht: 2026
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author Park, Jongwoo
Ranasinghe, Kanchana
Jang, Jinhyeok
Mata, Cristina
Jang, Yoo Sung
Ryoo, Michael S
author_facet Park, Jongwoo
Ranasinghe, Kanchana
Jang, Jinhyeok
Mata, Cristina
Jang, Yoo Sung
Ryoo, Michael S
contents Many Vision-Language-Action (VLA) models flatten image patches into a 1D token sequence, weakening the 2D spatial cues needed for precise manipulation. We introduce IVRA, a lightweight, training-free method that improves spatial understanding by exploiting affinity hints already available in the model's built-in vision encoder, without requiring any external encoder or retraining. IVRA selectively injects these affinity signals into a language-model layer in which instance-level features reside. This inference-time intervention realigns visual-token interactions and better preserves geometric structure while keeping all model parameters fixed. We demonstrate the generality of IVRA by applying it to diverse VLA architectures (LLaRA, OpenVLA, and FLOWER) across simulated benchmarks spanning both 2D and 3D manipulation (VIMA and LIBERO) and on various real-robot tasks. On 2D VIMA, IVRA improves average success by +4.2% over the baseline LLaRA in a low-data regime. On 3D LIBERO, it yields consistent gains over the OpenVLA and FLOWER baselines, including improvements when baseline accuracy is near saturation (96.3% to 97.1%). All code and models will be released publicly. Visualizations are available at: jongwoopark7978.github.io/IVRA
format Preprint
id arxiv_https___arxiv_org_abs_2601_16207
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle IVRA: Improving Visual-Token Relations for Robot Action Policy with Training-Free Hint-Based Guidance
Park, Jongwoo
Ranasinghe, Kanchana
Jang, Jinhyeok
Mata, Cristina
Jang, Yoo Sung
Ryoo, Michael S
Robotics
Many Vision-Language-Action (VLA) models flatten image patches into a 1D token sequence, weakening the 2D spatial cues needed for precise manipulation. We introduce IVRA, a lightweight, training-free method that improves spatial understanding by exploiting affinity hints already available in the model's built-in vision encoder, without requiring any external encoder or retraining. IVRA selectively injects these affinity signals into a language-model layer in which instance-level features reside. This inference-time intervention realigns visual-token interactions and better preserves geometric structure while keeping all model parameters fixed. We demonstrate the generality of IVRA by applying it to diverse VLA architectures (LLaRA, OpenVLA, and FLOWER) across simulated benchmarks spanning both 2D and 3D manipulation (VIMA and LIBERO) and on various real-robot tasks. On 2D VIMA, IVRA improves average success by +4.2% over the baseline LLaRA in a low-data regime. On 3D LIBERO, it yields consistent gains over the OpenVLA and FLOWER baselines, including improvements when baseline accuracy is near saturation (96.3% to 97.1%). All code and models will be released publicly. Visualizations are available at: jongwoopark7978.github.io/IVRA
title IVRA: Improving Visual-Token Relations for Robot Action Policy with Training-Free Hint-Based Guidance
topic Robotics
url https://arxiv.org/abs/2601.16207