现有 VLA 模型擅长静态任务,却在需要快速感知、时序预判与持续控制的动态物体操控场景中严重失效。 DynamicVLA 提出仅 0.4B 参数的轻量架构,配合 Continuous Inference(CI) 与 Latent-aware Action Streaming(LAAS),在推理与执行之间消除等待,实现 对运动物体的高频闭环控制。在自建 Dynamic Object Manipulation(DOM)基准上, 整体成功率达 47.06%,超越最强基线 3.46×。Existing VLA models excel at static tasks, yet fail badly in dynamic object manipulation scenarios that demand rapid perception, temporal anticipation and continuous control. DynamicVLA proposes a lightweight architecture with only 0.4B parameters, coupled with Continuous Inference (CI) and Latent-aware Action Streaming (LAAS), which removes the waiting between inference and execution and achieves high-frequency closed-loop control of moving objects. On the self-built Dynamic Object Manipulation (DOM) benchmark, the overall success rate reaches 47.06%, surpassing the strongest baseline by 3.46×.
机器人操控领域中,绝大多数 VLA 模型都假设目标物体静止不动。然而在真实场景中,物体往往处于运动状态——传送带上的工件、被推动的容器、弹跳的球体。 此时,推理延迟直接决定成败:即便数十毫秒的延迟,也会导致感知与执行之间的时序错位,令机器人抓取"幽灵位置"而非实际位置。In robotic manipulation, the vast majority of VLA models assume the target object stays still. In real scenarios, however, objects are often in motion - workpieces on a conveyor belt, containers being pushed, bouncing balls. Here inference latency directly decides success or failure: even a delay of tens of milliseconds induces a temporal mismatch between perception and execution, making the robot grasp a "ghost position" instead of the actual one.
"Dynamic object manipulation remains an open challenge for Vision-Language-Action (VLA) models, which…struggle in dynamic scenarios requiring rapid perception, temporal anticipation, and continuous control."
DynamicVLA 围绕三个核心设计:紧凑 VLA 架构、Continuous Inference 与 Latent-aware Action Streaming。架构追求极低延迟而非最大模型容量;推理策略则从根本上消除 chunk 间等待,并解决时序漂移问题。DynamicVLA is built around three core designs: a compact VLA architecture, Continuous Inference and Latent-aware Action Streaming. The architecture pursues extremely low latency rather than maximum model capacity; the inference strategy fundamentally removes inter-chunk waiting and resolves the temporal-drift problem.
语言 backbone 选用 SmolLM2-360M,并截断至 16 层(原 32 层),在多模态推理能力与推理速度之间取最优平衡(16 层:47.06% SR,0.226s;24 层:48.44% SR,0.317s)。 视觉编码器采用 FastViT 卷积架构,而非 Transformer 方案: "FastViT outperforms transformer-based encoders by lowering encoding latency through reduced tokenization"(FastViT:47.06% SR,0.226s 推理;Transformer 编码器:28.89% SR,0.233s 推理)。 Action expert 基于 Flow Matching Transformer,采用扩散式动作生成。 时序视觉输入选用稀疏双帧 {ot-2, ot}(以 25 FPS 采样,间隔 0.08s),兼顾速度感知与推理开销。The language backbone is SmolLM2-360M, truncated to 16 layers (originally 32 layers), which strikes the best balance between multimodal reasoning ability and inference speed (16 layers: 47.06% SR, 0.226s; 24 layers: 48.44% SR, 0.317s). The visual encoder adopts the FastViT convolutional architecture rather than a Transformer design: "FastViT outperforms transformer-based encoders by lowering encoding latency through reduced tokenization" (FastViT: 47.06% SR, 0.226s inference; Transformer encoder: 28.89% SR, 0.233s inference). The action expert is based on a Flow Matching Transformer and adopts diffusion-style action generation. The temporal visual input uses sparse dual frames {ot-2, ot} (sampled at 25 FPS, 0.08s apart), balancing velocity perception against inference overhead.
传统方案在执行完一个 action chunk 后才触发下一次推理,造成不可避免的等待间隙。CI 改为: "triggers inference cycles as soon as the previous inference finishes, independent of whether the previously predicted action sequence has been exhausted." 推理与执行全程流水线并行,消除 inter-chunk waiting,使机器人始终在执行动作的同时完成下一轮感知与预测。 消融实验显示,CI 将成功率从 36.11% 提升至 47.06%(+30.4%)。Conventional schemes trigger the next inference only after one action chunk has been fully executed, causing an unavoidable idle gap. CI instead: "triggers inference cycles as soon as the previous inference finishes, independent of whether the previously predicted action sequence has been exhausted." Inference and execution are pipelined in parallel throughout, removing inter-chunk waiting so that the robot always completes the next round of perception and prediction while executing actions. Ablations show that CI raises the success rate from 36.11% to 47.06% (+30.4%).
CI 引入新的时序问题:某一推理周期预测的 action 序列,在执行时目标物体已移动到新位置,导致旧 action 作用于"幽灵轨迹"。 LAAS 的解决方案:"Actions in At corresponding to timesteps earlier than t+m are discarded as outdated", 始终优先执行最新 chunk 中的动作。消融实验显示,在 CI 基础上叠加 LAAS 进一步将成功率从 39.72% 提升至 47.06%(+18.5%)。CI introduces a new temporal problem: by the time the action sequence predicted in one inference cycle is executed, the target object has already moved to a new position, so the stale actions act on a "ghost trajectory". The LAAS remedy: "Actions in At corresponding to timesteps earlier than t+m are discarded as outdated", always prioritizing the actions of the newest chunk. Ablations show that stacking LAAS on top of CI further raises the success rate from 39.72% to 47.06% (+18.5%).
为弥补现有基准缺乏动态场景的不足,作者构建了 DOM 基准:To make up for the lack of dynamic scenarios in existing benchmarks, the authors build the DOM benchmark:
在 DOM 仿真基准上,每种方法评估 1,800 次(10 场景 × 9 维度 × 20 次试验)。 所有 baseline 均在 DOM 数据集上 fine-tune,使用其官方实现与预训练权重。 真实世界评估使用次级机器臂驱动物体运动,每项任务 20 次试验 × 3 种配对运动-位置组合。On the DOM simulation benchmark, each method is evaluated 1,800 times (10 scenes × 9 dimensions × 20 trials). All baselines are fine-tuned on the DOM dataset using their official implementations and pretrained weights. Real-world evaluation uses a secondary robot arm to drive object motion, with 20 trials per task × 3 paired motion-position configurations.
| 方法Method | Interaction 均值Interaction mean | Perception 均值Perception mean | Generalization 均值Generalization mean | 整体 SR (%)Overall SR (%) |
|---|---|---|---|---|
| Diffusion Policy | 12.0 | 9.8 | 22.1 | 13.61(最强基线)13.61 (strongest baseline) |
| π0 | ~18 | ~10 | ~20 | ~16 |
| π0.5 | 21.0(最高)21.0 (highest) | — | — | ~15 |
| SmolVLA | — | — | — | ~12 |
| DynamicVLA(本文)DynamicVLA (ours) | 47.2 | 41.6 | 52.3 | 47.06 |
具体子维度亮点(均为 DynamicVLA vs. 最强 baseline):Highlights on individual sub-dimensions (all DynamicVLA vs. the strongest baseline):
| 配置Configuration | SR (%) | 关键结论Key finding |
|---|---|---|
| 135M backbone | 26.67 | 参数过少,表征能力不足Too few parameters; insufficient representational capacity |
| 360M backbone(本文)360M backbone (ours) | 47.06 | 效率与鲁棒性最优平衡Best balance of efficiency and robustness |
| 1.7B backbone | 24.33 | 延迟过高,动态任务性能反而下降Latency too high; performance on dynamic tasks drops instead |
| Transformer 视觉编码器Transformer visual encoder | 28.89 | token 增长导致延迟增大Token growth increases latency |
| FastViT(本文)FastViT (ours) | 47.06 | 降低编码延迟,成功率提升Lower encoding latency; higher success rate |
| 去掉 CIWithout CI | 36.11 | chunk 间等待拖累响应速度Inter-chunk waiting drags down responsiveness |
| CI + 去掉 LAASCI without LAAS | 39.72 | 过时动作造成时序错位Outdated actions cause temporal misalignment |
| CI + LAAS(本文)CI + LAAS (ours) | 47.06 | 完整系统Full system |
将 CI 与 LAAS 嵌入现有模型(无需重训练)的效果: π0.5 + CI/LAAS = 15.89% SR;SmolVLA + CI/LAAS = 25.56% SR;DynamicVLA = 47.06% SR。 说明大模型因推理延迟过高,无法充分发挥 CI/LAAS 的优势——低延迟架构是前提。The effect of embedding CI and LAAS into existing models (without retraining): π0.5 + CI/LAAS = 15.89% SR; SmolVLA + CI/LAAS = 25.56% SR; DynamicVLA = 47.06% SR. This shows that large models cannot fully exploit CI/LAAS because their inference latency is too high - a low-latency architecture is the prerequisite.
作者明确指出:"dynamic tasks tightly couple perception, reasoning, and execution, demanding architectures that preserve understanding under strict latency budgets." 截断 backbone(16 层而非 32 层)带来约 1.4% 绝对成功率的让步(24 层达 48.44%),是工程权衡而非最优精度。The authors state explicitly: "dynamic tasks tightly couple perception, reasoning, and execution, demanding architectures that preserve understanding under strict latency budgets." Truncating the backbone (16 layers instead of 32) concedes about 1.4% absolute success rate (24 layers reach 48.44%); this is an engineering trade-off rather than peak accuracy.
当前方案强调"短至中等时域的反应性交互",对于物体持续运动的长时序列场景(Long-horizon Sequencing 仅 40.5%)仍存在明显差距,尚未解决持续运动状态的长期跟踪问题。The current scheme emphasizes "reactive interaction over short to medium horizons"; a clear gap remains for long-horizon sequencing scenarios with continuously moving objects (Long-horizon Sequencing only 40.5%), and long-term tracking of sustained motion states is not yet solved.
数据采集流程依赖刚体 6D 位姿估计:"non-rigid or fluid dynamics with continuously evolving states…remain an open challenge." 现有管线无法处理布料、液体或形变物体。The data collection pipeline relies on rigid-body 6D pose estimation: "non-rigid or fluid dynamics with continuously evolving states…remain an open challenge." The existing pipeline cannot handle cloth, liquids or deformable objects.
即便是 DynamicVLA,在"干扰鲁棒性"子维度的成功率也仅为 26.5%,远低于其他维度,反映系统对不可控外部扰动的处理能力仍然有限。Even for DynamicVLA, the success rate on the "disturbance robustness" sub-dimension is only 26.5%, far below the other dimensions, reflecting that the system's ability to handle uncontrollable external perturbations is still limited.
将 CI 与 LAAS 迁移到较大模型(π0.5、SmolVLA 等)时收益有限,说明方法的有效性与低延迟架构深度绑定, 不能简单地将动态操控能力通过推理策略"插件式"叠加到高延迟大模型上。Transferring CI and LAAS to larger models (π0.5, SmolVLA, etc.) yields limited gains, showing that the effectiveness of the method is deeply tied to a low-latency architecture; dynamic manipulation ability cannot simply be stacked onto high-latency large models as a "plug-in" inference strategy.