LoopWAM

LoopWAM

Closed-Loop Generalist Policy Improvement
from Deployment Rollouts

Wenxuan Guo*Yingping Liang*Zhaoguo Wang*Ziyuan LiAngyuan MaZhenyu WuChengkun WangBingyao YuZe ChenBorui ZhangXiuwei Xu†Meng Zhang†Erjin ZhouJiwen Lu†

* Core Contributors† Corresponding Authors

Tsinghua UniversityDexmalLoopeva

Closed-loop self-improvement

LoopWAM turns real-world experience into better robot policies. By learning from successful, suboptimal, and failed rollouts alongside expert demonstrations, it closes the loop between deployment and improvement.

LoopWAM: deploy, collect, and improve through real-world experience.

Method and key techniques

LoopWAM method: mixed-quality expert and rollout data train video and action branches through joint attention, source-dependent noise, quality-weighted supervision and quality steering.

Joint video–action modeling

Video and action tokens interact through bidirectional attention throughout joint denoising.

Source-dependent noise

Lower-noise rollout actions guide video prediction to learn their observed physical consequences.

Quality-aware learning

Quality conditions and weights guide action learning. Every rollout teaches video prediction, without imitating failed actions.

Real-world and simulation leaderboards

Best overall performance among the methods compared in our paper on three benchmarks.

43.33%

RoboChallenge Table30-V2

Real-world success

94.5%

RoboTwin 2.0

Average success

49.5%

RoboCasa365

Overall success

Multi-task self-improvement

30 tasks. Four embodiments. One multi-task model per embodiment, improving through three rounds of real-world deployment.

Multi-task deployment and rollout data feedback.

RoboChallenge success rate

43.33%
Round 3+19.66 pp

Performance across multiple deployment rounds

Post-training self-improvement
on a challenging task

After expert post-training, two rounds of deployment-driven learning improve the DOS-W1 model on challenging shirt folding.

Shirt-folding success rate

55.56%
Stage 3+42.36 pp

Evaluation success rates. Trajectory demos play at up to 4× speed.

Deployment Stage 1

The deployed model is trained on expert demonstrations.

9 random trajectories

Deployment Stage 2

Model trained on expert demonstrations and Round 1 rollouts.

9 random trajectories

Deployment Stage 3

Model trained on expert demonstrations and Round 1&2 rollouts.

9 deployment trajectories

Consistent action and video generation

Video and action generation, learned together. Each example pairs observed video on the left with LoopWAM’s prediction on the right.

Arrange Fruits

Trajectory 1
Trajectory 2

Pen Container

Trajectory 1
Trajectory 2

Stack Bowls

Trajectory 1
Trajectory 2

Lint Roller

Trajectory 1
Trajectory 2