Act, Think or Abstain: Complexity-Aware Adaptive Inference for Vision-Language-Action Models

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Izzo, Riccardo Andrea, Bardaro, Gianluca, Matteucci, Matteo
Format: Preprint
Publié: 2026
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866912944921509888
author Izzo, Riccardo Andrea
Bardaro, Gianluca
Matteucci, Matteo
author_facet Izzo, Riccardo Andrea
Bardaro, Gianluca
Matteucci, Matteo
contents Current research on Vision-Language-Action (VLA) models predominantly focuses on enhancing generalization through established reasoning techniques. While effective, these improvements invariably increase computational complexity and inference latency. Furthermore, these mechanisms are typically applied indiscriminately, resulting in the inefficient allocation of resources for trivial tasks while simultaneously failing to provide the uncertainty estimation necessary to prevent catastrophic failure on out-of-distribution tasks. Inspired by human cognition, we propose an adaptive framework that dynamically routes VLA execution based on the complexity of the perceived state. Our approach transforms the VLA's vision-language backbone into an active detection tool by projecting latent embeddings into an ensemble of parametric and non-parametric estimators. This allows the system to execute known tasks immediately (Act), reason about ambiguous scenarios (Think), and preemptively halt execution when encountering significant physical or semantic anomalies (Abstain). In our empirical analysis, we observe a phenomenon where visual embeddings alone are superior for inferring task complexity due to the semantic invariance of language. Evaluated on the LIBERO and LIBERO-PRO benchmarks as well as on a real robot, our vision-only configuration achieves 80% F1-Score using as little as 5% of training data, establishing itself as a reliable and efficient task complexity detector.
format Preprint
id arxiv_https___arxiv_org_abs_2603_05147
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Act, Think or Abstain: Complexity-Aware Adaptive Inference for Vision-Language-Action Models
Izzo, Riccardo Andrea
Bardaro, Gianluca
Matteucci, Matteo
Computer Vision and Pattern Recognition
Robotics
Current research on Vision-Language-Action (VLA) models predominantly focuses on enhancing generalization through established reasoning techniques. While effective, these improvements invariably increase computational complexity and inference latency. Furthermore, these mechanisms are typically applied indiscriminately, resulting in the inefficient allocation of resources for trivial tasks while simultaneously failing to provide the uncertainty estimation necessary to prevent catastrophic failure on out-of-distribution tasks. Inspired by human cognition, we propose an adaptive framework that dynamically routes VLA execution based on the complexity of the perceived state. Our approach transforms the VLA's vision-language backbone into an active detection tool by projecting latent embeddings into an ensemble of parametric and non-parametric estimators. This allows the system to execute known tasks immediately (Act), reason about ambiguous scenarios (Think), and preemptively halt execution when encountering significant physical or semantic anomalies (Abstain). In our empirical analysis, we observe a phenomenon where visual embeddings alone are superior for inferring task complexity due to the semantic invariance of language. Evaluated on the LIBERO and LIBERO-PRO benchmarks as well as on a real robot, our vision-only configuration achieves 80% F1-Score using as little as 5% of training data, establishing itself as a reliable and efficient task complexity detector.
title Act, Think or Abstain: Complexity-Aware Adaptive Inference for Vision-Language-Action Models
topic Computer Vision and Pattern Recognition
Robotics
url https://arxiv.org/abs/2603.05147