VLA-FAIL introduces a lightweight framework for detecting failures in vision-language-action models used in robotic manipulation. It combines two novel detectors: the first-layer Mahalanobis distance (LLMD) identifies out-of-distribution states by comparing token-wise deviations in last-layer features to training data, while the second, action chunk consistency (ACC), detects failures by spotting inconsistencies between consecutive action chunks in receding-horizon control. The authors also propose a threshold‑independent metric, “AUCPDT,” to evaluate detection accuracy and latency, and show through real‑world and simulation experiments that LLMD and ACC together provide reliable and early failure detection, outperforming more expensive baseline methods.
By Florian Seligmann, Emiliyan Gospodinov, Enes Ulas Dincer, Gerhard Neumann
The paper introduces VLA‑Tug, a lightweight probe that monitors latent layers of Vision‑Language‑Action models to detect failures early and predict failure modes. By supervising on pre‑failure segments, it improves early detection by up to 30% at matched false‑positive rates and maintains valid missed‑detection and false‑alarm bounds in 86% of runs under unseen task shifts, outperforming existing baselines. The method also raises top‑3 accuracy on unseen tasks by up to 44% and supports real‑time, edge‑efficient monitoring for safer deployment.
By Michal P. Podolinsky, Yunhao Yang, Daniel Little, Hong Lu, Rohan Siva, Olin Goudey, Neel P. Bhatt, Matthias Scheutz, Ufuk Topcu
The paper introduces FailureSpot, a label‑efficient method for detecting failures at the timestamp level in vision‑language‑action (VLA) policies. It first generates weak supervision from unlabeled VLA action chunks by identifying abnormal patterns, then employs active learning to annotate only the most uncertain trajectories. Experiments on multiple VLA policies demonstrate improved performance for both timestamp‑level and trajectory‑level failure detection.
By Jie Ma, Zongxi Liu, Yi Zhu
arXiv:2606. 29699v1 Announce Type: cross Abstract: Vision Language Action models combine perception, language grounding, and control in a single policy, but their failures are hard to diagnose once visual conditions shift.
By Dipesh Tharu Mahato, Rachel Ren
arXiv:2608.29967v1 Announce Type: cross
Abstract: Vision-Language-Action (VLA) models demonstrate strong semantic understanding yet exhibit systematic failures during deployment. The conditions under...
By Owen Kwon, Pablo Ortega-Kral, Arthur Bucker, Jean Oh
Vision‑Language‑Action models (VLAs) often fail to follow language instructions because they rely on vision shortcuts learned from biased datasets. The authors introduce LIBERO‑CF, a counterfactual benchmark that tests language following by providing alternative task instructions for the same scene layouts, revealing widespread counterfactual failures. They propose Counterfactual Action Guidance (CAG), a dual‑branch inference scheme that amplifies language conditioning, which consistently improves language grounding and task success across diverse VLAs without requiring extra data or architectural changes.
By Yu Fang, Yuchun Feng, Dong Jing, Jiaqi Liu, Yue Yang, Zhenyu Wei, Daniel Szafir, Mingyu Ding
FailBench is a new benchmark for robot failure detection, containing 2,197 manipulation attempts from 14 public sources, with 75% of failures occurring naturally. The study evaluates 13 vision‑language model (VLM) detectors, finding the best model achieves only 0.77 mean balanced accuracy, and that fine‑tuned failure detectors often underperform general‑purpose VLMs. Performance varies with visual evidence, excelling when object motion is observable but dropping to near chance on contact‑intensive assembly tasks, and input‑level cropping of outcome‑relevant regions improves the top detector by 2.4 percentage points.
By Zaruhi Navasardyan, Tatul Danielyan, Hrant Davtyan
arXiv:2603. 06001v2 Announce Type: replace-cross Abstract: Vision-Language-Action (VLA) models enable robots to perform manipulation tasks directly from natural language instructions and are increasingly viewed as a foundation for generalist robotic policies.
By Ninghao Zhang, Bin Zhu, Shijie Zhou, Jingjing Chen
RePO‑VLA is a recovery‑driven policy optimization framework for Vision‑Language‑Action models that separates success, recovery, and failure trajectories. It introduces Recovery‑Aware Initialization, a Progress‑Aware Semantic Value Function, and Value‑Conditioned Refinement to learn from both successful and failed rollouts, enabling the policy to prefer high‑progress actions without online failure detectors. The authors also present the Failure‑Recovery Benchmark (FRBench) and demonstrate that RePO‑VLA raises adversarial success rates from 20% to 75% on average in simulated and real‑world bimanual tasks.
By Weijia Liufu, Xiaoyu Guo, Ruiyi Chen, Jingzhi Liu, Kaidong Zhang, Xiwen Liang, Jianqi Lin, Dawei Sun, Yuze Wang, Rongtao Xu, Bingqian Lin, Bowen Yang, Tongtong Cao, Bowen Peng, Dongyu Zhang, Guangrun Wang, Min Wang, Liang Lin, Xiaodan Liang
The paper introduces an event‑grounded interpretability pipeline for Vision‑Language‑Action (VLA) policies, using sparse autoencoders (SAEs) whose feature analysis is anchored to behavioral events rather than textual context. Keyframes are extracted from end‑effector trajectories and clustered with visual, robot‑state, and temporal cues, guiding SAE feature ranking and optionally enriched with vision‑language‑model (VLM) annotations. Experiments on two simulation architectures and a real‑robot study show that event‑grounded ranking produces the strongest causal effects on OpenVLA and transfers to continuous action chunks of π_{0.5}, while also highlighting the limitations of SAE as an intervention basis.
By Xinchen Jin, Aditya Chatterjee, Pranav Kumar, Rohan Paleja
The paper introduces Hide-and-Seek, a framework for detecting failures in Vision‑Language‑Action (VLA) models during robot execution. It treats failure detection as a coarsely supervised learning problem, using inter‑trajectory and intra‑trajectory contrastive objectives to localize failure‑indicative actions without step‑level annotations. Experiments on LIBERO, VLABench, and a real‑world robotic platform show that Hide‑and‑Seek achieves state‑of‑the‑art multi‑task failure detection performance across several VLA policies.
By Seongheon Park, Wendi Li, Changdae Oh, Samuel Yeh, Zsolt Kira, Michael Hagenow, Sharon Li
arXiv:2604.16677v2 Announce Type: replace-cross
Abstract: Vision-language-action (VLA) models have emerged as generalist robotic controllers that map visual observations and language instructions to...
By Zongyao Lyu, Lingling Chen, William J. Beksi