NeurIPS 2026 / POSTER

Separate Then Align Representations

Control First.
Robustness Next.

Decoupled Representation Learning for Visual RL Generalization

Chanyong Heo · Hyelyn Jeong · Jongchan Park · Seungjun Oh · Yusung Kim
Sungkyunkwan University · Department of Artificial Intelligence · Department of Computer Science and Engineering

STAR learns a control-relevant representation first, then aligns a robust visual pathway to the frozen control interface offline—without additional environment interaction or controller retraining.

THE CENTRAL IDEA01 / 02
01
◎CONTROL LEARNING

Establish the reference.

Learn the control encoder and policy from source observations using weak augmentation.

DrQ-style RLForward dynamics
Freeze the control interface
02
◇OFFLINE ROBUSTIFICATION

Recover it under shifts.

Train only the robust encoder and aligner to match that fixed reference.

Replay bufferFrozen controller
SAME CONTROLLER, ROBUST VISUAL PATHWAY
✓ Fixed downstream policy✓ Offline alignment✓ Zero-shot evaluation
THE IDEA ↘

Visual robustness should not come at the expense of learning to control.

Conventional approaches often optimize control and robustness through the same evolving visual representation. STAR changes the order: learn a reliable control interface first; robustify the observation pathway afterward. The downstream controller remains untouched.

Why separate
control and robustness?

Robustness objectives and the critic can push on the same representation while online training is still changing its meaning.

THE COUPLED PARADIGM
Control objective+Robustness objective
↓
One changing visual encoder

Two learning signals jointly modify the representation during actor–critic training.

STAR: SEPARATE, THEN ALIGN
Learn control→Freeze reference
↓
Align only the visual pathway

A fixed reference turns online interference into offline representation recovery.

FIGURE 1 / EMPIRICAL DIAGNOSTIC

Coupled learning shows higher drift and TD residuals.

DrQ normalized to 1.0Enlarge SVG ↗
Paper's Figure 1 comparing in-distribution return, representation drift and normalized temporal-difference error across DMC and Robosuite.
Compared with DrQ, coupled-learning methods exhibit increased representation drift and normalized TD error. On Robosuite, the measured values reach 4.54× and 5.57×, respectively. These are diagnostics of association, not proof of causality. On mobile, swipe across the figure to inspect the details.

Two stages.
One fixed interface.

STAR is the full framework. Post-Representation Alignment (PRA) is the offline second stage that recovers the control reference from perturbed observations.

FIGURE 2 / STAR FRAMEWORK

From control-oriented learning to offline alignment

NeurIPS 2026 · Fig. 2Enlarge SVG ↗
The reference encoder and downstream controller are fixed in Stage 2. Only the robust encoder and alignment module receive updates. On mobile, swipe across the figure to inspect the details.
STAGE 0101 ↗

Learn control

Train a DrQ-style actor–critic on weakly augmented source observations. An auxiliary forward-dynamics objective helps form a control-relevant latent reference.

Critic loss + λ × dynamics loss
STAGE 02 / PRA02 ↗

Align offline

Initialize a robust encoder from the control encoder. Use the retained replay buffer with paired weak/strong views, and train the robust pathway against a frozen target.

Robust latent ≈ stopgrad(reference latent)
INFERENCE03 ↗

Reuse the controller

Replace the source encoder with the aligned robust encoder and adapter. Pass its features to the original actor or action-generation module unchanged.

No downstream policy retraining
500KStage-1 RL environment steps
100KStage-2 offline updates (visual RL)
0Additional environment steps in Stage 2

These budgets refer to the visual RL experiments. The Diffusion Policy adaptation uses a separate 20-epoch offline alignment schedule.

Robust across different
ways to change a scene.

The paper evaluates a frozen control policy under changes in appearance, video backgrounds, and a separately adapted geometric-perturbation family.

A / DMC-GB4 tasks

Visual control

Walker Walk, Cheetah Run, Finger Spin and Cartpole SwingUp. Color and video backgrounds probe appearance robustness.

DMC-GB Walker Walk training appearance, Color Easy, Color Hard, Video Easy and Video Hard.
Original · Color Easy/Hard · Video Easy/HardOpen high-res ↗Swipe image →
B / ROBOSUITE2 tasks

Contact-rich manipulation

Door and TwoArmPegInHole evaluate visual generalization with interaction-sensitive objects and geometry.

Robosuite task scene under Original, Easy, Medium, Hard and Video visual conditions.
Original · Easy · Medium · Hard · VideoOpen high-res ↗Swipe image →
C / DIFFUSION POLICY2 tasks

Pretrained visuomotor policy

PickPlaceCan and NutAssemblySquare test whether the same offline alignment principle works for a fixed diffusion action module.

Square manipulation setting with progressively more severe Easy, Medium and Hard visual shifts.
Square: Easy · Medium · HardOpen high-res ↗Swipe image →

Preserve control.
Improve generalization.

Aggregate returns are averaged over the benchmark's reported evaluation conditions. Diffusion Policy uses success rate (%), not episodic return.

DMC-GB / shifted return
709.1→795.7

Best competing baseline (SimGRL) → STAR

ROBOSUITE / shifted return
257.0→380.5

Best competing baseline (SECANT) → STAR

SQUARE HARD / SUCCESS
15.3%→67.3%

Pretrained Diffusion Policy → DP + PRA

PAPER RESULTS

Quantitative comparisons

Choose a table to inspect the reported numbers.

DMC-GB average episodic return over four tasks
SettingDrQSVEASGQNSMGSimGRLSECANTSTAR
Original avg.826.8759.3756.0766.3753.3795.0857.5
Shifted avg.459.9582.1657.8706.4709.1587.3795.7

Appearance-based shifts: Color Easy/Hard and Video Easy/Hard. Mean over four seeds; shifted average excludes Original and covers 16 task–shift pairs.

Generalization
in motion.

Explore task-level rollouts across appearance and geometric shifts. Select a benchmark, task and shift family. Each clip is labeled by benchmark, task and evaluation condition.

DEMONSTRATION EXPLOREREXPERIMENT ROLLOUTS

What the results
tell us.

A two-stage design gives control representation learning and visual robustness adaptation separate, complementary roles.

01

Control quality matters.

A good reference latent supports the downstream policy; auxiliary dynamics supervision can strengthen that reference, particularly for manipulation.

02

Alignment is the robustness mechanism.

Matched ablations show large gains from adding PRA even without the Stage-1 dynamics objective.

03

Policies remain untouched.

PRA can adapt visual RL or a pretrained diffusion policy by changing the visual pathway rather than retraining action selection.

Scope & limitations.

Effectiveness depends on the quality of the fixed control reference. Geometric robustness requires an augmentation selected for the target transformation family, and the work does not establish robustness to arbitrary dynamics or task-semantic changes. The paper does not evaluate vision-language-action models.

Reference
the work.

Cite the NeurIPS 2026 poster. Verify final proceedings metadata against the camera-ready record before external publication.

BibTeX / NeurIPS 2026 Poster
@inproceedings{heo2026star,
  title     = {Control First, Robustness Next: Decoupled Representation Learning for Visual RL Generalization},
  author    = {Heo, Chanyong and Jeong, Hyelyn and Park, Jongchan and Oh, Seungjun and Kim, Yusung},
  booktitle = {Advances in Neural Information Processing Systems},
  year      = {2026},
  note      = {Poster}
}