WORLD-ACTION MODELS · REAL-WORLD TOUCH

Tactile Prediction and
Real-Time Action Correction

in World-Action Models for Contact-Rich Manipulation

Zipei Ma1,2,3·Xiaofei Wei1,2·Junzhe Jiang1·Shunlin Lu3·Li Zhang1,2

1 School of Data Science, Fudan University2 Shanghai Innovation Institute3 NeoteAI

The full story, in three minutes.

ENGLISH NARRATION / 03:08
64%

Average task success+16 percentage points over T-Rex

30.4ms

Per tactile correction32.9 Hz with a reusable cache

20.7×

Lower inference latencyCompared with regenerating a chunk

01 / OVERVIEW

Predict contact.
Correct in real time.

A robot can plan what happens next.
Touch tells it what is happening now.

Small contact errors can jam an insertion or break a fragile object. Future tactile predictions provide useful expectations, but those predictions are made before an action chunk begins.

TacPAC connects this anticipated contact to live tactile feedback. A tactile expert reads each new tactile observation against a cached representation of the prediction and plan, then corrects the actions that have yet to execute. The robot keeps moving throughout.

THE IDEA / EXPECTATION MEETS TOUCHFollow the signal ↓

Contact can change everything.

Without tactile predictionFailure
Fragile grasp without tactile predictionTactile observation in the failed grasp
TacPACSuccess
Successful grasp with TacPACTactile observation in the successful grasp
Camera observationTactile observation
PREDICT → COMPARE → CORRECT

Touch has context.

Read what happens against what the plan expected.

Prediction-informed tactile correctionPredicted tactile context and a new live tactile frame feed the tactile expert. A delta action is added to the planned action. The waveforms are conceptual, not experimental measurements. EXPECTED CONTACT LIVE TOUCH Tactile expertRead + correct NEXT ACTIONSâ + Δa
64%full TacPAC
Prediction only37%
Prediction + correction64%
Teaser rebuilt from the supplied editable artwork. Sensor images show selected outcomes; rates are from all evaluation trials (Table 1). Signal curves illustrate the mechanism.
02 / METHOD

From expected contact
to corrected action.

Plan once per chunk. Read new touch against the plan. Update what comes next.

FIGURE 2 / THREE EXPERTS, ONE FEEDBACK LOOP
TacPAC three-expert architectureStage one jointly predicts visual and tactile futures and an action chunk. A clean prefill caches tactile and action keys and values. During execution, the tactile expert combines that cache with live touch to predict delta actions, applied only to the unexecuted suffix. STAGE 1 · TACTILE-PREDICTIVE BASE MODELSTAGE 2 · EXECUTION-TIME CORRECTION Current contextInstruction · two camera views · touch · proprioception Video expertAction expertFuture visual + tactile tokensPlanned action chunk â SHARED SELF-ATTENTION · JOINT GENERATION Predicted visual + tactile future 48 actions / 1.6 seconds CLEAN PREFILL → TACTILE + ACTION K/VReusable layer-wise KV cachePredicted contact + planned action context New tactile frameAt execution offset mTactile expertCurrent touch attends to cached context Delta action Δa → corrected suffixâ + Δa, only from m + d onwardContinue execution · observe touch again Base model is frozen when training the tactile expert.
01

Predict and plan together.

The video and action experts jointly generate future visual and tactile observations and an action chunk through shared self-attention.

Architecture redrawn from the supplied pipeline artwork and paper Figure 2. Image tiles indicate visual and tactile modalities.

01

Predict & plan

A video expert predicts future visual and tactile observations while an action expert jointly generates an action chunk.

02

Cache the expectation

A clean prefill pass stores predicted tactile and action representations as a reusable, layer-wise key–value cache.

03

Correct with live touch

Each new tactile frame triggers one expert pass, producing delta actions for the unexecuted part of the chunk.

FIGURE 3 / ASYNCHRONOUS INFERENCE

The plan updates.
The robot keeps moving.

Observe at m. Compute while the arm moves. Apply the delta only from m + d onward.

Already executedCommitted during latencyEligible for correction
0m = 16m + d = 18H = 48

32 actions remain; the correction can update 30 actions after the 2-step latency window.

30 / 48 actions

Interactive timing illustration, slowed for clarity. H = 48; robot control = 30 Hz. d is measured from recent correction latency, not fixed. The paper reports d = 0 for most execution; only 1.6% of calls span ≥1 control step.

03 / REAL-ROBOT EXPERIMENTS

Contact makes the difference.

Explore complete rollouts across precision insertion, fragile-object handling, and force-sensitive manipulation.

Charger-plug insertion

Precise alignment under constrained contact.

iVideos show selected successful or failed rollouts, not all trials. Success rates summarize 20 trials per method per task. Speed applies equally to all three videos; each stops at its final frame.

Figure 6 · Inside the experimental setupROBOT + SENSORS +
Flexiv Rizon 4 robot with wrist-mounted RealSense D405 and third-person RealSense D435i cameras.

One arm. Vision and touch.

A Flexiv Rizon 4 uses two InTac S1 tactile sensors in its gripper, a wrist-mounted Intel RealSense D405, and a third-person Intel RealSense D435i.

TacPAC takes a task instruction, two camera views, proprioception, and two tactile views. All methods are evaluated on the same five tasks with 20 trials per task.

Full evaluation protocol in the paper ↗
04 / RESULTS

Better across all five tasks.

64% average success, with prediction and correction working together.

FIGURE 4

Seven methods. Five contact-rich tasks.

+16 pp

Average gain over the strongest baseline, T-Rex.
20 trials per method per task · 100 trials per method overall

Exact values for every methodSUCCESS RATE (%) +
Paper Figure 4. Episode success rate (%).
MethodPlugFruitChipBottleCardAverage
TABLE 1

Which tactile pathways matter?

Prediction alone raises average success from 22% to 37%. Giving the corrector access to predicted touch raises 47% to 64%.

Pathways available to each variant

Complete component-ablation table5 VARIANTS / ALL TASKS +
Paper Table 1. “Without correction” corresponds to “w/o tactile expert.”
VariantPredictionCorrectionTactile cachePlugFruitChipBottleCardAverage
FIGURE 5

Brief contact transitions. Outsized tactile change.

4.9%

of all frames

→
18.6%

of total tactile change

Contact transitions are the most active phase in every task, yet account for only a small fraction of the prediction target.

(a) Relative tactile change

Mean adjacent-frame change relative to the episode mean. Dashed line = 1.

(b) Share of episode frames

Percentage of frames assigned to each execution phase.
View digitized phase values and source notesAPPROXIMATE VALUES +

Bar heights and error bars were recovered from the original PDF vector paths, not raw measurements. Values below are approximate; error bars retain the published geometry (the caption does not specify their statistical definition). The 4.9% and 18.6% callouts are reported directly in Section 4.3.

Download digitized values (JSON) ↓
TABLE 2

Fast enough to act on new touch.

20.7×

lower latency per correction
than regenerating a chunk

30.4 ms / 32.90 Hz
Average wall-clock latency and corresponding rate, paper Table 2.
Inference stageLatency ↓Rate ↑
Chunk generation · ten flow steps628.6 ms1.59 Hz
Cache prefill · one clean pass62.6 ms15.97 Hz
Tactile correction · one pass30.4 ms32.90 Hz
FIGURES 7–11 / SUPPLEMENT

Contact, through the course of execution.

VISIONSix visual observations from a successful charger-plug rolloutTOUCHCorresponding tactile observations
ApproachContact transitionSustained contactPost-contact
0.0 s

Dark line: tactile activity cₜ (left axis). Rust line: measured gripper width (right axis). Curves preserve the original PDF vector paths. Download trace geometry ↓ The representative training-episode trace and the successful-rollout image strip are from separate episodes, as stated in the supplement; the time cursor applies to the trace only.

Explore all results in the paper, Figures 4–11 & Tables 1–2 ↗
05 / CITATION

Build on TacPAC.

If you find this work useful,
please consider citing our paper.

Explore the code ↗
BIBTEX
@article{ma2026tacpac,
  title={TacPAC: Tactile Prediction and Real-Time Action
         Correction in World-Action Models for
         Contact-Rich Manipulation},
  author={Ma, Zipei and Wei, Xiaofei and Jiang, Junzhe
          and Lu, Shunlin and Zhang, Li},
  journal={arXiv preprint arXiv:2609.05266},
  year={2026},
  url={https://arxiv.org/abs/2609.05266}
}