Closing the Representational Gap for VLAs in Dynamic Settings

Zhenyang Feng*, Jimin Heo*, Erik Sudderth, Unnat Jain
University of California, Irvine
* Equal contribution
Accepted at CoRL 2026

Abstract

Vision-language-action (VLA) models have achieved impressive performance in quasi-static manipulation, but struggle in dynamic manipulation tasks because they operate on a single observation at inference time. We identify two representational failures that underlie this limitation. The first is motion ambiguity, where a single observation does not include scene dynamics and therefore cannot anticipate the future state of moving objects. The second is state aliasing, where visually similar observations from different points in a task require different actions. We show that these failures persist regardless of model scale and inference latency, proving that the bottleneck is missing temporal context rather than model capacity.

Based on this insight, we propose TEMPO, which augments a pretrained VLA with two temporal inputs: a motion summary extracted from a frozen video foundation model to resolve motion ambiguity and a compact proprioceptive history to resolve state aliasing. TEMPO requires no modification to the backbone and adds minimal compute overhead at training or deployment. Across four dynamic manipulation tasks, it improves Bottle Handover success from 44% to 74% and is the only method that solves state aliasing. Probing and ablation studies confirm that each temporal signal independently addresses its corresponding failure. We further release TEMPO-Bench, a benchmark of over 50k annotated frames for evaluating motion-aware robot perception in both regression and multiple-choice formats.

Dynamic Tasks 🐇 No Quasi-static-ness! 🐢

We evaluate on a bimanual platform across four dynamic tasks (Drop Catch, Bottle Handover, Flick Catch, and Wine Pour), each with a moving target and sequential subtasks that a single-frame observation cannot resolve. Every clip on this page is a rollout from our trained TEMPO policy.

TEMPO Methodology

TEMPO adds two compact temporal signals to a frozen VLA, each fixing one failure mode with near-zero overhead and no architectural change. TEMPOMOT is an object-agnostic motion token from a frozen video foundation model that summarizes how the scene is moving, fixing motion ambiguity. TEMPOACT is a compact summary of the robot's recent joint history that tells the policy which task phase it is in, fixing state aliasing. Motion encoding runs in a background thread, so it adds essentially no inference-time cost; we give the full architecture and a latency breakdown in the paper.

Results

Side-by-side rollouts of the same task: the asynchronous method VLASH versus TEMPO. VLASH cannot tell how the scene is moving or which phase of the task it is in, so it mistimes the grasp or stalls entirely. TEMPO tracks the moving target and commits at the right moment.

VLASH: Complete Miss
Success rate: 38%
VLASH
19
5
8
18
TEMPO (Ours): Catches
Success rate: 74%
TEMPO
37
3
10
Success Near Catch Gripper Miss Complete Miss

Receiving a bottle from a walking person. VLASH reaches for where the bottle was and misses it entirely; TEMPO estimates the bottle's velocity and times the grasp to intercept it. The bars beside each video break that method's 50 Bottle Handover rollouts into success (green) and failure modes (reds); hover any segment for details.


VLASH: Misses the Catch
Success rate: 38%
VLASH
19
2
6
23
TEMPO (Ours): Catches
Success rate: 66%
TEMPO
33
4
7
6
Success Lagged behind hand Overshoot Premature move

A ball is dropped into the workspace and the gripper has to be under it to make the catch. Because VLASH cannot perceive how the ball is moving, it falls back on constantly sweeping the gripper left and right even when the ball is still or barely drifting, so it is rarely in the right place when the ball comes down; TEMPO reads the recent motion and closely shadows the hand, staying under the ball through the drop. The bars beside each video break that method's 50 Drop Catch rollouts into success (green) and failure modes (reds); hover any segment for details.


VLASH: Fails to Track
Success rate: 20%
VLASH
10
3
37
TEMPO (Ours): Tracks & Catches
Success rate: 66%
TEMPO
33
4
9
4
Success Failed to Grab Plate Failed to Track Hand Failed to Catch Ball

VLASH never picks up the object's motion, so its gripper fails to follow the ball and the catch is missed. TEMPO learns the object-motion-to-action correspondence, tracks the appropriate target, and catches it on time. The bars beside each video break that method's 50 Flick Catch rollouts into success (green) and per-stage failures (reds); hover any segment for details.


VLASH: Spills More
Wine retained: 94.0%
TEMPO (Ours): Clean Pour
Wine retained: 98.1%

The robot pours beads into a pot the human keeps moving; success is the percentage of beads retained in the pot. Both methods complete the pour, but VLASH lags the moving pot and spills more, while TEMPO tracks the pot and pours cleanly.


State Aliasing: Stalls vs. Completes

VLASH: Aliased, Fails to Start
Success rate: 0%
TEMPO (Ours): Disambiguates, Succeeds
Success rate: 68%

The approach and retract phases of the gripper look nearly identical from a single frame. With this state aliasing present in the demonstrations, VLASH collapses and cannot act; TEMPO's proprioceptive history disambiguates the two phases, so the gripper approaches and retracts normally and completes the task. See a deeper dive in Why TEMPOACT helps? below.

TEMPO can complementarily use motion and proprioceptive information

We visualize the action expert's attention mass over a representative Flick Catch episode. Attention on TEMPOMOT rises as the human hand starts moving, corresponding to major movement in the observation, while TEMPOACT steadily gains attention during the hand- following phase and drops back down after the ball is caught. The two signals are consulted at distinct moments: motion during tracking, proprioceptive history at commitment; the paper develops this attention analysis in full.


Why TEMPOMOT helps?
Its motion latent encodes object velocity that a single frame cannot reveal.

For each task we trace the active object's trajectory over the past 16 frames (blue = 16 frames ago → red = now; yellow dot = current position). A probe then predicts this motion from each model's aggregated hidden state; a higher R² means the representation encodes object motion.

Ground-truth 16-frame active-object trajectory per task
MethodDrop CatchBottle HandoverFlick CatchWine PourAvg.
RTC0.310.46-0.070.060.19
VLASH0.280.430.030.090.21
TEMPO (Ours)0.330.520.570.440.47

MLP probe R² over active object velocity. Where a single frame cannot reveal motion (Flick Catch, Wine Pour), RTC and VLASH collapse toward zero while TEMPO stays high.


Why TEMPOACT helps? State Aliasing!

Why does a single-frame policy stall before it even starts? Because the same image recurs at opposite moments of the task. In the real episodes below, the arm passes through the same configuration once on the way in and once on the way out: the two highlighted frames are near-identical (their visual similarity, measured by a frozen vision encoder, is shown in the middle) yet demand opposite actions. Use the toggle to switch task.

--
DINOv2 cosine
similarity
play next 5s

Without proprioceptive history, VLASH oscillates and stalls.

The approach and retract phases of the gripper produce nearly identical observations, so VLASH, conditioned on a single frame, cannot tell them apart and oscillates between reaching and withdrawing, failing to even start the task. This is the artifact that drives both RTC and VLASH to 0% on the state-aliased Flick Catch and Wine Pour tasks. TEMPO completely resolves it: with a compact proprioceptive history, the policy knows which phase it is in and the gripper approaches and retracts normally, as shown in the state-aliasing success rollout above.

BibTeX

@misc{feng2026tempolearningtemporalcontext,
      title={TEMPO: Learning Temporal Context for Dynamic Robot Manipulation},
      author={Zhenyang Feng and Jimin Heo and Erik B. Sudderth and Unnat Jain},
      year={2026},
      eprint={2609.16864},
      archivePrefix={arXiv},
      primaryClass={cs.RO},
      url={https://arxiv.org/abs/2609.16864},
}