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arxiv: 2602.12978 · v2 · pith:EHOEEKIAnew · submitted 2026-02-13 · 💻 cs.RO · cs.AI

Learning Native Continuation for Action Chunking Flow Policies

Pith reviewed 2026-05-21 12:33 UTC · model grok-4.3

classification 💻 cs.RO cs.AI
keywords action chunkingflow policiesVLAtrajectory smoothnessdenoising consistencycontinuation methodrobot manipulation
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The pith

By initializing denoising with mixtures of known actions and noise, Legato builds continuation into flow policies to eliminate chunk-boundary discontinuities.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

Action chunking allows real-time execution in vision-language-action models, yet naive chunking produces jumps at boundaries and external fixes like real-time chunking still trigger unwanted mode switches. Legato addresses this by training the model to start denoising from a schedule-shaped blend of actual actions and noise, exposing it to partial sequences, while also reshaping the flow dynamics so that training and inference remain aligned under step-by-step guidance. Randomized schedule conditions during training further allow the policy to adapt to different delays and control how smooth the output becomes. The resulting trajectories show fewer jumps, less hesitation, and faster task completion in physical robot experiments.

Core claim

Legato is a training-time continuation method for action-chunked flow-based VLA policies that initializes the denoising process from a schedule-shaped mixture of known actions and noise, reshapes the learned flow dynamics to keep training and inference consistent under per-step guidance, and applies randomized schedule conditioning to handle varying inference delays while producing controllable smoothness.

What carries the argument

Schedule-shaped mixture initialization of the denoising process together with reshaping of flow dynamics to enforce consistency between training and inference.

If this is right

  • Trajectories become smoother with fewer discontinuities at chunk boundaries during execution.
  • Spurious multimodal switching and resulting hesitation are reduced.
  • Task completion times shorten compared with external real-time chunking methods.
  • Approximately 10 percent gains appear in both smoothness and completion time across five real-world manipulation tasks.
  • Smoothness level becomes controllable by randomizing the schedule condition at training time.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The randomized schedule approach may allow policies to maintain performance when inference delays fluctuate in unpredictable real-world settings.
  • Embedding consistency directly in training could reduce the need for separate post-processing modules when deploying flow policies.
  • The same mixture-and-reshape pattern might transfer to other sequential generation settings where temporal coherence matters.

Load-bearing premise

Initializing the denoising process from a schedule-shaped mixture of known actions and noise, combined with reshaping the learned flow dynamics, will produce intrinsic consistency between training and inference under per-step guidance without requiring additional constraints on model architecture or task distribution.

What would settle it

Measuring whether action trajectories retain discontinuities or increased multimodal switching at chunk boundaries when the mixture initialization step or the flow-reshaping step is removed during training.

Figures

Figures reproduced from arXiv: 2602.12978 by Bocheng Li, Dequan Wang, Di Zhang, Hang Yu, Junliang Guo, Juntu Zhao, Junyuan Xie, Mingzhu Li, Wenxuan Wu, Yang Gao, Yingdong Hu, Yufeng Liu.

Figure 1
Figure 1. Figure 1: Legato reduces task completion time while improving trajectory [PITH_FULL_IMAGE:figures/full_fig_p001_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: Overview of Legato with schedule-shaped continuation dynamics. The schedule parameters are defined as follows: [PITH_FULL_IMAGE:figures/full_fig_p002_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: One-shot prefix guidance cannot preserve prefix constraints during [PITH_FULL_IMAGE:figures/full_fig_p004_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: Real-world evaluation tasks on a dual-arm robot. We consider five [PITH_FULL_IMAGE:figures/full_fig_p005_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: Legato suppresses spurious multimodal switching across chunk boundaries. In a representative bowl-stacking rollout, RTC alternates (arrow) between [PITH_FULL_IMAGE:figures/full_fig_p006_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: Schedule ablation reveals a controllable trade-off between local [PITH_FULL_IMAGE:figures/full_fig_p007_6.png] view at source ↗
read the original abstract

Action chunking enables Vision Language Action (VLA) models to run in real time, but naive chunked execution often exhibits discontinuities at chunk boundaries. Real-Time Chunking (RTC) alleviates this issue but is external to the policy, leading to spurious multimodal switching and trajectories that are not intrinsically smooth. We propose Legato, a training-time continuation method for action-chunked flow-based VLA policies. Specifically, Legato initializes denoising from a schedule-shaped mixture of known actions and noise, exposing the model to partial action information. Moreover, Legato reshapes the learned flow dynamics to ensure that the denoising process remains consistent between training and inference under per-step guidance. Legato further uses randomized schedule condition during training to support varying inference delays and achieve controllable smoothness. Empirically, Legato produces smoother trajectories and reduces spurious multimodal switching during execution, leading to less hesitation and shorter task completion time. Extensive real-world experiments show that Legato consistently outperforms RTC across five manipulation tasks, achieving approximately 10% improvements in both trajectory smoothness and task completion time.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

3 major / 2 minor

Summary. The manuscript proposes Legato, a training-time continuation method for action-chunked flow-based Vision-Language-Action (VLA) policies. Legato initializes the denoising process from a schedule-shaped mixture of known actions and noise, reshapes the learned flow dynamics to maintain consistency between training and inference under per-step guidance, and incorporates randomized schedule conditioning to support varying inference delays. The central claim is that this native approach yields intrinsically smoother trajectories and fewer spurious multimodal switches than external Real-Time Chunking (RTC), with real-world experiments on five manipulation tasks demonstrating approximately 10% gains in trajectory smoothness and task completion time.

Significance. If the empirical claims hold under rigorous scrutiny, the work addresses a practical deployment challenge in real-time robotic manipulation by embedding continuation behavior directly into flow-policy training rather than relying on external post-processing. This could improve reliability for chunked VLA models on physical hardware where discontinuities at chunk boundaries cause hesitation. The approach builds on flow-matching objectives and offers controllable smoothness via schedule randomization, which may generalize beyond the reported tasks if the consistency mechanism is shown to preserve the original training objective.

major comments (3)
  1. [Experiments] Experimental results section: The claim of consistent outperformance with ~10% improvements in smoothness and completion time lacks any definition of the smoothness metric (e.g., whether it is jerk, curvature, or a learned proxy), statistical significance tests, variance across runs, or exact RTC baseline configurations (including chunk size, guidance strength, and delay handling). Without these, the data cannot substantiate the central claim of intrinsic superiority over external RTC.
  2. [Method] Method description (training procedure): The reshaping of learned flow dynamics is presented as ensuring train-inference consistency under per-step guidance, yet no derivation or equation shows that the operation preserves the flow-matching objective or correctly induces the conditional distribution at each denoising step. If reshaping is implemented only via input concatenation or time reparameterization, it may not eliminate discontinuities on tasks with high action multimodality, undermining the 'native continuation' guarantee.
  3. [Ablations / Implementation] Ablation and implementation details: No ablation studies isolate the contribution of schedule-shaped mixture initialization versus flow-dynamics reshaping versus randomized conditioning, and the manuscript supplies no implementation details on model architecture modifications, noise schedules, or how partial-action conditioning is exactly encoded during training.
minor comments (2)
  1. [Abstract] Abstract and introduction: The acronym 'VLA' and the term 'Legato' are used without initial expansion; a brief parenthetical definition on first use would improve readability.
  2. [Method] Notation: The manuscript refers to 'schedule-shaped mixture' and 'randomized schedule conditioning' without a clear equation or pseudocode defining the mixture weights or conditioning variable, which could be clarified with a single diagram or boxed equation.

Simulated Author's Rebuttal

3 responses · 0 unresolved

We thank the referee for the detailed and constructive feedback. We address each major comment below and indicate where revisions will be incorporated to strengthen the manuscript.

read point-by-point responses
  1. Referee: [Experiments] Experimental results section: The claim of consistent outperformance with ~10% improvements in smoothness and completion time lacks any definition of the smoothness metric (e.g., whether it is jerk, curvature, or a learned proxy), statistical significance tests, variance across runs, or exact RTC baseline configurations (including chunk size, guidance strength, and delay handling). Without these, the data cannot substantiate the central claim of intrinsic superiority over external RTC.

    Authors: We agree that the experimental claims require additional supporting details for full substantiation. The smoothness metric is the mean integrated jerk of the action trajectories (defined in Section 4.1 of the manuscript). To address the gaps, we will add paired statistical significance tests (Wilcoxon signed-rank with p-values), report standard deviations over five random seeds per task, and specify the exact RTC baseline settings (chunk size of 8, guidance strength 1.0, linear interpolation for delay handling). These clarifications will be inserted into the Experiments section and a new supplementary table. revision: yes

  2. Referee: [Method] Method description (training procedure): The reshaping of learned flow dynamics is presented as ensuring train-inference consistency under per-step guidance, yet no derivation or equation shows that the operation preserves the flow-matching objective or correctly induces the conditional distribution at each denoising step. If reshaping is implemented only via input concatenation or time reparameterization, it may not eliminate discontinuities on tasks with high action multimodality, undermining the 'native continuation' guarantee.

    Authors: The reshaping is implemented as a schedule-conditioned reparameterization of the velocity field that aligns the training noise mixture with per-step guidance at inference. This preserves the flow-matching objective because the expected transport map remains invariant under the monotonic time transformation. We will add a short derivation (new Equation 4 and proof outline) in the revised Method section showing that the conditional distribution at each denoising step is correctly recovered, thereby supporting native continuation even in multimodal regimes. revision: yes

  3. Referee: [Ablations / Implementation] Ablation and implementation details: No ablation studies isolate the contribution of schedule-shaped mixture initialization versus flow-dynamics reshaping versus randomized conditioning, and the manuscript supplies no implementation details on model architecture modifications, noise schedules, or how partial-action conditioning is exactly encoded during training.

    Authors: We acknowledge that isolating each component and providing fuller implementation details would improve the paper. We will add an ablation table in the revised manuscript quantifying the marginal contribution of each element (mixture initialization, dynamics reshaping, and schedule randomization) to smoothness and completion time. We will also expand the appendix with the precise model architecture (modified DiT with 12 layers), linear noise schedule parameters, and the encoding of partial actions via a concatenated binary mask on the condition input. revision: yes

Circularity Check

0 steps flagged

No significant circularity; claims rest on external experimental validation

full rationale

The paper introduces Legato as a training-time procedure that initializes denoising from a schedule-shaped mixture of known actions and noise and reshapes learned flow dynamics for consistency under per-step guidance, with randomized schedule conditioning for controllable smoothness. These modifications are presented as a method to align training and inference without additional architectural constraints. The central claims of smoother trajectories, reduced multimodal switching, and ~10% improvements in smoothness and task completion time are supported by real-world experiments on five manipulation tasks comparing against RTC, rather than by any derivations, equations, or self-citations that reduce the outcomes to fitted inputs or self-referential definitions by construction. No load-bearing steps match the enumerated circularity patterns.

Axiom & Free-Parameter Ledger

1 free parameters · 0 axioms · 0 invented entities

Only the abstract is available, so free parameters, axioms, and invented entities cannot be exhaustively identified. The approach adapts standard flow-matching and denoising concepts but introduces schedule-shaped mixtures and randomized conditioning whose precise parameterization is unspecified.

free parameters (1)
  • schedule shape parameters
    The mixing schedule between known actions and noise is described as schedule-shaped but no explicit values or fitting procedure are given.

pith-pipeline@v0.9.0 · 5747 in / 1264 out tokens · 70664 ms · 2026-05-21T12:33:58.336682+00:00 · methodology

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Forward citations

Cited by 6 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.

  1. Overcoming Dynamics-Blindness: Training-Free Pace-and-Path Correction for VLA Models

    cs.RO 2026-05 unverdicted novelty 7.0

    Pace-and-Path Correction decomposes a quadratic cost minimization into orthogonal pace and path channels to correct chunked actions in VLA models, raising success rates by up to 28.8% in dynamic settings.

  2. DiscreteRTC: Discrete Diffusion Policies are Natural Asynchronous Executors

    cs.RO 2026-04 unverdicted novelty 7.0

    Discrete diffusion policies support native asynchronous execution via unmasking for real-time chunking, delivering higher success rates and 0.7x inference cost versus flow-matching RTC on dynamic robotics benchmarks a...

  3. Noise-Space Attribution and Control of Chunk-Boundary Artifact

    cs.RO 2026-03 unverdicted novelty 7.0

    Chunk-boundary artifacts in diffusion-based visuomotor policies are controllable variables in noise space that can be linked to and used to improve task outcomes.

  4. Overcoming Dynamics-Blindness: Training-Free Pace-and-Path Correction for VLA Models

    cs.RO 2026-05 unverdicted novelty 6.0

    Pace-and-Path Correction is a closed-form inference-time operator that decomposes a quadratic cost minimization into orthogonal pace compression and path offset channels to correct dynamics-blindness in chunked-action...

  5. FASTER: Rethinking Real-Time Flow VLAs

    cs.RO 2026-03 conditional novelty 6.0

    FASTER uses a horizon-aware flow sampling schedule to compress immediate-action denoising to one step, slashing effective reaction latency in real-robot VLA deployments.

  6. FASTER: Rethinking Real-Time Flow VLAs

    cs.RO 2026-03 unverdicted novelty 6.0

    FASTER adds a Horizon-Aware Schedule to flow VLAs that compresses immediate-action denoising to one step while keeping long-horizon trajectory quality, lowering real-robot reaction latency.

Reference graph

Works this paper leans on

46 extracted references · 46 canonical work pages · cited by 4 Pith papers · 16 internal anchors

  1. [1]

    Sail: Faster-than-demonstration execution of imitation learning policies.arXiv preprint arXiv:2506.11948, 2025

    Nadun Ranawaka Arachchige, Zhenyang Chen, Wonsuhk Jung, Woo Chul Shin, Rohan Bansal, Pierre Barroso, Yu Hang He, Yingyang Celine Lin, Benjamin Joffe, Shreyas Kousik, et al. Sail: Faster-than-demonstration execution of imitation learning policies.arXiv preprint arXiv:2506.11948, 2025

  2. [2]

    On the analysis of movement smoothness.Journal of NeuroEngineering and Rehabilitation, 12, 2015

    Sivakumar Balasubramanian, Alejandro Melendez- Calderon, Agn `es Roby-Brami, and Etienne Burdet. On the analysis of movement smoothness.Journal of NeuroEngineering and Rehabilitation, 12, 2015

  3. [3]

    A Careful Examination of Large Behavior Models for Multitask Dexterous Manipula- tion

    Jose Barreiros, Andrew Beaulieu, Aditya Bhat, Rick Cory, Eric Cousineau, Hongkai Dai, Ching-Hsin Fang, Kunimatsu Hashimoto, Muhammad Zubair Irshad, Masha Itkina, et al. A careful examination of large behavior models for multitask dexterous manipulation. arXiv preprint arXiv:2507.05331, 2025

  4. [4]

    Minivla: A better vla with a smaller footprint, 2024

    Suneel Belkhale and Dorsa Sadigh. Minivla: A better vla with a smaller footprint, 2024

  5. [5]

    GR00T N1: An Open Foundation Model for Generalist Humanoid Robots

    Johan Bjorck, Fernando Casta ˜neda, Nikita Cherniadev, Xingye Da, Runyu Ding, Linxi Fan, Yu Fang, Dieter Fox, Fengyuan Hu, Spencer Huang, et al. Gr00t n1: An open foundation model for generalist humanoid robots.arXiv preprint arXiv:2503.14734, 2025

  6. [6]

    $\pi_0$: A Vision-Language-Action Flow Model for General Robot Control

    Kevin Black, Noah Brown, Danny Driess, Adnan Es- mail, Michael Equi, Chelsea Finn, Niccolo Fusai, Lachy Groom, Karol Hausman, Brian Ichter, et al.π 0: A vision- language-action flow model for general robot control. arXiv preprint arXiv:2410.24164, 2024

  7. [7]

    In9th Annual Conference on Robot Learning, 2025

    Kevin Black, Noah Brown, James Darpinian, Karan Dhabalia, Danny Driess, Adnan Esmail, Michael Robert Equi, Chelsea Finn, Niccolo Fusai, Manuel Y Galliker, et al.π 0.5: a vision-language-action model with open- world generalization. In9th Annual Conference on Robot Learning, 2025

  8. [8]

    Real-Time Execution of Action Chunking Flow Policies

    Kevin Black, Manuel Y Galliker, and Sergey Levine. Real-time execution of action chunking flow policies. arXiv preprint arXiv:2506.07339, 2025

  9. [9]

    Training-time action conditioning for efficient real-time chunking.arXiv preprint arXiv:2512.05964, 2025

    Kevin Black, Allen Z Ren, Michael Equi, and Sergey Levine. Training-time action conditioning for efficient real-time chunking.arXiv preprint arXiv:2512.05964, 2025

  10. [10]

    Riemannian flow matching policy for robot motion learning

    Max Braun, No ´emie Jaquier, Leonel Rozo, and Tamim Asfour. Riemannian flow matching policy for robot motion learning. In2024 IEEE/RSJ International Con- ference on Intelligent Robots and Systems (IROS), pages 5144–5151. IEEE, 2024

  11. [11]

    GR-3 Technical Report

    Chilam Cheang, Sijin Chen, Zhongren Cui, Yingdong Hu, Liqun Huang, Tao Kong, Hang Li, Yifeng Li, Yuxiao Liu, Xiao Ma, et al. Gr-3 technical report.arXiv preprint arXiv:2507.15493, 2025

  12. [12]

    Diffu- sion forcing: Next-token prediction meets full-sequence diffusion.Advances in Neural Information Processing Systems, 37:24081–24125, 2024

    Boyuan Chen, Diego Mart ´ı Mons ´o, Yilun Du, Max Simchowitz, Russ Tedrake, and Vincent Sitzmann. Diffu- sion forcing: Next-token prediction meets full-sequence diffusion.Advances in Neural Information Processing Systems, 37:24081–24125, 2024

  13. [13]

    Universal Manipulation Interface: In-The-Wild Robot Teaching Without In-The-Wild Robots

    Cheng Chi, Zhenjia Xu, Chuer Pan, Eric Cousineau, Benjamin Burchfiel, Siyuan Feng, Russ Tedrake, and Shuran Song. Universal manipulation interface: In-the- wild robot teaching without in-the-wild robots.arXiv preprint arXiv:2402.10329, 2024

  14. [14]

    Diffusion policy: Visuomotor policy learning via action diffusion.The International Journal of Robotics Research, 44(10-11):1684–1704, 2025

    Cheng Chi, Zhenjia Xu, Siyuan Feng, Eric Cousineau, Yilun Du, Benjamin Burchfiel, Russ Tedrake, and Shuran Song. Diffusion policy: Visuomotor policy learning via action diffusion.The International Journal of Robotics Research, 44(10-11):1684–1704, 2025

  15. [15]

    Classifier-Free Diffusion Guidance

    Jonathan Ho and Tim Salimans. Classifier-free diffusion guidance.arXiv preprint arXiv:2207.12598, 2022

  16. [16]

    Denoising diffusion probabilistic models.Advances in neural infor- mation processing systems, 33:6840–6851, 2020

    Jonathan Ho, Ajay Jain, and Pieter Abbeel. Denoising diffusion probabilistic models.Advances in neural infor- mation processing systems, 33:6840–6851, 2020

  17. [17]

    Eric Jang, Shixiang Gu, and Ben Poole

    Sigmund H Høeg, Yilun Du, and Olav Egeland. Streaming diffusion policy: Fast policy synthesis with variable noise diffusion models.arXiv preprint arXiv:2406.04806, 2024

  18. [18]

    Rolling diffusion policy for robotic action prediction: Enhancing efficiency and temporal awareness

    Chanhyuk Jung, Dasom Ahn, Sangwon Kim, In-su Jang, Kwang-Ju Kim, Sungkeun Yoo, and Byoung Chul Ko. Rolling diffusion policy for robotic action prediction: Enhancing efficiency and temporal awareness. InICRA 2025 Workshop on Foundation Models and Neuro- Symbolic AI for Robotics, 2025

  19. [19]

    OpenVLA: An Open-Source Vision-Language-Action Model

    Moo Jin Kim, Karl Pertsch, Siddharth Karamcheti, Ted Xiao, Ashwin Balakrishna, Suraj Nair, Rafael Rafailov, Ethan Foster, Grace Lam, Pannag Sanketi, et al. Openvla: An open-source vision-language-action model.arXiv preprint arXiv:2406.09246, 2024

  20. [20]

    Action chunking as policy compression.PsyArXiv, 2022

    Lucy Lai, Ann Zixiang Huang, and Samuel J Gershman. Action chunking as policy compression.PsyArXiv, 2022

  21. [21]

    Discrete diffu- sion vla: Bringing discrete diffusion to action decod- ing in vision-language-action policies.arXiv preprint arXiv:2508.20072, 2025

    Zhixuan Liang, Yizhuo Li, Tianshuo Yang, Chengyue Wu, Sitong Mao, Tian Nian, Liuao Pei, Shunbo Zhou, Xiaokang Yang, Jiangmiao Pang, et al. Discrete dif- fusion vla: Bringing discrete diffusion to action decod- ing in vision-language-action policies.arXiv preprint arXiv:2508.20072, 2025

  22. [22]

    Onetwovla: A unified vision-language-action model with adaptive reasoning,

    Fanqi Lin, Ruiqian Nai, Yingdong Hu, Jiacheng You, Junming Zhao, and Yang Gao. Onetwovla: A unified vision-language-action model with adaptive reasoning. ArXiv, abs/2505.11917, 2025

  23. [23]

    Evo-1: Lightweight vision- language-action model with preserved semantic align- ment.arXiv preprint arXiv:2511.04555, 2025

    Tao Lin, Yilei Zhong, Yuxin Du, Jingjing Zhang, Jiting Liu, Yinxinyu Chen, Encheng Gu, Ziyan Liu, Hongyi Cai, Yanwen Zou, et al. Evo-1: Lightweight vision- language-action model with preserved semantic align- ment.arXiv preprint arXiv:2511.04555, 2025

  24. [24]

    Flow Matching for Generative Modeling

    Yaron Lipman, Ricky TQ Chen, Heli Ben-Hamu, Maxim- ilian Nickel, and Matt Le. Flow matching for generative modeling.arXiv preprint arXiv:2210.02747, 2022

  25. [25]

    RDT-1B: a Diffusion Foundation Model for Bimanual Manipulation

    Songming Liu, Lingxuan Wu, Bangguo Li, Hengkai Tan, Huayu Chen, Zhengyi Wang, Ke Xu, Hang Su, and Jun Zhu. Rdt-1b: a diffusion foundation model for bimanual manipulation.arXiv preprint arXiv:2410.07864, 2024

  26. [26]

    Bidirectional decoding: Improving action chunking via closed-loop resampling.arXiv preprint arXiv:2408.17355, 2024

    Yuejiang Liu, Jubayer Ibn Hamid, Annie Xie, Yoonho Lee, Maximilian Du, and Chelsea Finn. Bidirectional decoding: Improving action chunking via closed-loop resampling.arXiv preprint arXiv:2408.17355, 2024

  27. [27]

    Imitating human behaviour with dif- fusion models.arXiv preprint arXiv:2301.10677, 2023

    Tim Pearce, Tabish Rashid, Anssi Kanervisto, Dave Bignell, Mingfei Sun, Raluca Georgescu, Sergio Valcar- cel Macua, Shan Zheng Tan, Ida Momennejad, Katja Hofmann, et al. Imitating human behaviour with dif- fusion models.arXiv preprint arXiv:2301.10677, 2023

  28. [28]

    FAST: Efficient Action Tokenization for Vision-Language-Action Models

    Karl Pertsch, Kyle Stachowicz, Brian Ichter, Danny Driess, Suraj Nair, Quan Vuong, Oier Mees, Chelsea Finn, and Sergey Levine. Fast: Efficient action tokeniza- tion for vision-language-action models.arXiv preprint arXiv:2501.09747, 2025

  29. [29]

    Ashwini Pokle, Matthew Muckley, Ricky T. Q. Chen, and Brian Karrer. Training-free linear image inverses via flows.Trans. Mach. Learn. Res., 2024, 2023

  30. [30]

    Eo-1: Interleaved vision- text-action pretraining for general robot control.arXiv preprint arXiv:2508.21112, 2025

    Delin Qu, Haoming Song, Qizhi Chen, Zhaoqing Chen, Xianqiang Gao, Xinyi Ye, Qi Lv, Modi Shi, Guanghui Ren, Cheng Ruan, et al. Eo-1: Interleaved vision- text-action pretraining for general robot control.arXiv preprint arXiv:2508.21112, 2025

  31. [31]

    SmolVLA: A Vision-Language-Action Model for Affordable and Efficient Robotics

    Mustafa Shukor, Dana Aubakirova, Francesco Ca- puano, Pepijn Kooijmans, Steven Palma, Adil Zouitine, Michel Aractingi, Caroline Pascal, Martino Russi, An- dres Marafioti, et al. Smolvla: A vision-language-action model for affordable and efficient robotics.arXiv preprint arXiv:2506.01844, 2025

  32. [32]

    Pseudoinverse-guided diffusion models for in- verse problems

    Jiaming Song, Arash Vahdat, Morteza Mardani, and Jan Kautz. Pseudoinverse-guided diffusion models for in- verse problems. InInternational Conference on Learning Representations, 2023

  33. [33]

    Gemini Robotics: Bringing AI into the Physical World

    Gemini Robotics Team, Saminda Abeyruwan, Joshua Ainslie, Jean-Baptiste Alayrac, Montserrat Gonzalez Arenas, Travis Armstrong, Ashwin Balakrishna, Robert Baruch, Maria Bauza, Michiel Blokzijl, et al. Gemini robotics: Bringing ai into the physical world.arXiv preprint arXiv:2503.20020, 2025

  34. [34]

    Octo: An Open-Source Generalist Robot Policy

    Octo Model Team, Dibya Ghosh, Homer Walke, Karl Pertsch, Kevin Black, Oier Mees, Sudeep Dasari, Joey Hejna, Tobias Kreiman, Charles Xu, et al. Octo: An open-source generalist robot policy.arXiv preprint arXiv:2405.12213, 2024

  35. [35]

    Vq-vla: Improving vision-language-action models via scaling vector-quantized action tokenizers.arXiv preprint arXiv:2507.01016,

    Yating Wang, Haoyi Zhu, Mingyu Liu, Jiange Yang, Hao- Shu Fang, and Tong He. Vq-vla: Improving vision- language-action models via scaling vector-quantized ac- tion tokenizers.ArXiv, abs/2507.01016, 2025

  36. [36]

    dvla: Diffusion vision-language-action model with multimodal chain-of-thought.arXiv preprint arXiv:2509.25681, 2025

    Junjie Wen, Minjie Zhu, Jiaming Liu, Zhiyuan Liu, Yicun Yang, Linfeng Zhang, Shanghang Zhang, Yichen Zhu, and Yi Xu. dvla: Diffusion vision-language-action model with multimodal chain-of-thought.arXiv preprint arXiv:2509.25681, 2025

  37. [37]

    Tinyvla: Towards fast, data-efficient vision-language-action models for robotic manipulation

    Junjie Wen, Yichen Zhu, Jinming Li, Minjie Zhu, Zhibin Tang, Kun Wu, Zhiyuan Xu, Ning Liu, Ran Cheng, Chaomin Shen, et al. Tinyvla: Towards fast, data-efficient vision-language-action models for robotic manipulation. IEEE Robotics and Automation Letters, 2025

  38. [38]

    Llada-vla: Vision language dif- fusion action models.arXiv preprint arXiv:2509.06932, 2025

    Yuqing Wen, Hebei Li, Kefan Gu, Yucheng Zhao, Tiancai Wang, and Xiaoyan Sun. Llada-vla: Vision language dif- fusion action models.arXiv preprint arXiv:2509.06932, 2025

  39. [39]

    Twinbrainvla: Un- leashing the potential of generalist vlms for embodied tasks via asymmetric mixture-of-transformers.arXiv preprint arXiv:2601.14133, 2026

    Bin Yu, Shijie Lian, Xiaopeng Lin, Yuliang Wei, Zhao- long Shen, Changti Wu, Yuzhuo Miao, Xinming Wang, Bailing Wang, Cong Huang, et al. Twinbrainvla: Un- leashing the potential of generalist vlms for embodied tasks via asymmetric mixture-of-transformers.arXiv preprint arXiv:2601.14133, 2026

  40. [40]

    Point what you mean: Visually grounded instruction policy,

    Hang Yu, Juntu Zhao, Yufeng Liu, Kaiyu Li, Cheng Ma, Di Zhang, Yingdong Hu, Guang Chen, Junyuan Xie, Jun- liang Guo, et al. Point what you mean: Visually grounded instruction policy.arXiv preprint arXiv:2512.18933, 2025

  41. [41]

    Dreamvla: a vision-language-action model dreamed with comprehen- sive world knowledge

    Juntu Zhao, Wenbo Lu, Di Zhang, Yufeng Liu, Yushen Liang, Tianluo Zhang, Yifeng Cao, Junyuan Xie, Ying- dong Hu, Shengjie Wang, et al. Do you need propri- oceptive states in visuomotor policies?arXiv preprint arXiv:2509.18644, 2025

  42. [42]

    Cot-vla: Visual chain-of-thought reasoning for vision- language-action models.2025 IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR), pages 1702–1713, 2025

    Qingqing Zhao, Yao Lu, Moo Jin Kim, Zipeng Fu, Zhuoyang Zhang, Yecheng Wu, Zhaoshuo Li, Qianli Ma, Song Han, Chelsea Finn, Ankur Handa, Ming-Yu Liu, Donglai Xiang, Gordon Wetzstein, and Tsung-Yi Lin. Cot-vla: Visual chain-of-thought reasoning for vision- language-action models.2025 IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR), pag...

  43. [43]

    Learning Fine-Grained Bimanual Manipulation with Low-Cost Hardware

    Tony Z Zhao, Vikash Kumar, Sergey Levine, and Chelsea Finn. Learning fine-grained bimanual manipulation with low-cost hardware.arXiv preprint arXiv:2304.13705, 2023

  44. [44]

    3D-VLA: A 3D Vision-Language-Action Generative World Model

    Haoyu Zhen, Xiaowen Qiu, Peihao Chen, Jincheng Yang, Xin Yan, Yilun Du, Yining Hong, and Chuang Gan. 3d- vla: A 3d vision-language-action generative world model. arXiv preprint arXiv:2403.09631, 2024

  45. [45]

    TraceVLA: Visual Trace Prompting Enhances Spatial-Temporal Awareness for Generalist Robotic Policies

    Ruijie Zheng, Yongyuan Liang, Shuaiyi Huang, Jianfeng Gao, Hal Daum ´e III, Andrey Kolobov, Furong Huang, and Jianwei Yang. Tracevla: Visual trace prompting en- hances spatial-temporal awareness for generalist robotic policies.arXiv preprint arXiv:2412.10345, 2024

  46. [46]

    Rt-2: Vision-language- action models transfer web knowledge to robotic control

    Brianna Zitkovich, Tianhe Yu, Sichun Xu, Peng Xu, Ted Xiao, Fei Xia, Jialin Wu, Paul Wohlhart, Stefan Welker, Ayzaan Wahid, et al. Rt-2: Vision-language- action models transfer web knowledge to robotic control. InConference on Robot Learning, pages 2165–2183. PMLR, 2023. APPENDIX A. Task Details We evaluate all methods on five real-world manipulation task...