LiMA: Bridging Long-term Imagination to Real-time Dexterous Manipulation via Asynchronous Diffusion
Organizations: State Key Laboratory of Multimedia Information Processing, School of Computer Science, Peking University · Beijing Academy of Artificial Intelligence
Abstract
Dexterous manipulation demands long-term foresight and rapid reactive control. Vision-Language-Action (VLA) models, while proficient in high-level reasoning, often lack a fine-grained understanding of physical dynamics and spatial perception. Conversely, World-Action Models (WAMs) typically suffer from high inference latency due to iterative generation. These deficiencies result in a critical temporal misalignment where the model's intent fails to adapt to rapid physical contact changes. To overcome this fundamental bottleneck, we propose LiMA, an asynchronous dual-system generative framework that systematically decouples intent planning from reactive execution. LiMA organizes computation into a multi-scale hierarchy: a slow system handles sparse long-horizon spatiotemporal intent generation, while a fast system focuses on dense high-frequency motion refinement. To align sparse intent predictions with dense action trajectories, we introduce a Latent Schrödinger Bridge Coupling mechanism that formulates refinement as an entropy-regularized probabilistic transport process. LiMA reduces inference latency by 45.8% compared with Cosmos-Policy via asynchronous decoupling. Evaluated across six bimanual dexterous manipulation tasks spanning multiple horizons, LiMA achieves an overall success rate of 70.8% and an average subtask success rate of 78.9%, while maintaining performance in unseen scenarios. The project website is available at https://ccdcs.github.io/LiMA_repo/
Figures & tables
| Method | Stack cup | Roll T-shirt | Cook Rice | Make Sandwich | Make Coffee | Assemble package | Time (ms) | ||||||
| SR | PSR | SR | PSR | SR | PSR | SR | PSR | SR | PSR | SR | PSR | - | |
| GR00T N1.6 | 85.0% | 87.5% | 70.0% | 71.7% | 70.0% | 72.0% | 65.0% | 72.5% | 55.0% | 71.7 % | 50.0% | 61.7% | 270 |
| VPP | 80.0% | 80.0% | 55.0% | 56.7% | 55.0% | 60.0% | 50.0% | 61.3% | 50.0% | 56.7% | 40.0% | 48.3% | 225 |
| Internvla-a1 | 90.0% | 90.0% | 75.0% | 88.3% | 70.0% | 78.0% | 65.0% | 77.5% | 50.0% | 66.7% | 50.0% | 58.3% | 360 |
| cosmos-policy | 80.0% | 82.5% | 60.0% | 70.0% | 60.0% | 67.0% | 60.0% | 71.3% | 55.0% | 63.3% | 45.0% | 51.7% | 600 |
| LiMA (Ours) | 90.0% | 95.0% | 75.0% | 83.3% | 80.0% | 82.0% | 70.0% | 80.0% | 60.0% | 70.0% | 50.0% | 63.3% | 325 |
| Variant | Cook Rice | Stack Cup |
| w/o Future Visual Intent | ||
| Gaussian Init. + Cross-Attn | ||
| Flow Matching | ||
| LiMA |
| (a) Component Ablation | (b) Denoising Steps | (c) System Ratio ( ) | ||||||
| Component | S.R. | Time | Steps | S.R. | Time | Ratio | S.R. | Time |
| Full (LiMA) | 80% | 0.325s | 5 | 65% | 0.23s | 1:9 | 50% | 0.28s |
| w/o Adapt. | 60% | - | 10 | 80% | 0.325s | 2:8 | 65% | 0.31s |
| w/o Tokens | 55% | - | 15 | 85% | 0.43s | 3:7 | 80% | 0.325s |
| w/o Fast-Slow | 80% | 0.45s | 20 | 80% | 0.51s | 4:6 | 70% | 0.34s |
Appendix figures & tables6 assets
Supplementary material from the paper’s appendix.
Appendix
| Task | P1 | P2 | P3 | P4 | P5 |
| Stack Cup | Grasp cup | Stack cup | – | – | – |
| Roll T-shirt | Grasp corners | Fold garment | Pick and place | – | – |
| Cook Rice | Grasp spoon | Scoop rice | Transfer rice | Close cooker | Return spoon |
| Make Sandwich | Pick up tongs | Grasp lettuce | Place lettuce and return tongs | Cover with bread | – |
| Make Coffee | Pick up coffee bag | Pick up kettle | Hand over cup | – | – |
| Assemble Package | Pick up black part | Pick up transparent part | Combine parts | – | – |
| Task | Method | P1(%) | P2(%) | P3(%) | P4(%) | P5(%) | PSR(%) |
| Stack Cup | LiMA | 100 | 90.0 | – | – | – | 95.0 |
| Cosmos-Policy | 85.0 | 80.0 | – | – | – | 82.5 | |
| GR00T N1.6 | 90.0 | 85.0 | – | – | – | 87.5 | |
| VPP | 80.0 | 80.0 | – | – | – | 80.0 | |
| InternVLA-A1 | 90.0 | 90.0 | – | – | – | 90.0 | |
| Roll T-shirt | LiMA | 95.0 | 80.0 | 75.0 | – | – | 83.3 |
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