Organizations: State Key Laboratory of Multimedia Information Processing, School of Computer Science, Peking University · Beijing Academy of Artificial Intelligence
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
Figure 2: Overview of LiMA. LiMA asynchronously coordinates long-horizon foresight and real-time reactive control through a dual-system architecture. The Future Dreamer produces structured intent, while the Motion Refiner performs high-frequency latent refinement. A Latent Schrödinger Bridge Coupling mechanism maintains latent-level coherence between the two systems for manipulation.
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
Table 1: Comparison of LiMA and baselines on Real-World Tasks. Each experiment is evaluated with 20 trials. Inference speed is evaluated on a NVIDIA H100 GPU.
Figure 3
Variant
Cook Rice
Stack Cup
w/o Future Visual Intent
61.7±7.6
76.7±2.9
Gaussian Init. + Cross-Attn
70.0±5.0
78.3±2.9
Flow Matching
73.3±2.9
83.3±5.8
LiMA
78.3±2.9
93.3±5.8
Table 2: Bridge design ablation. Success rates (%) are reported as mean ± standard deviation over three seeds, with 20 real-world trials per seed.
(a) Component Ablation
(b) Denoising Steps
(c) System Ratio ( Ns:Nf )
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
Table 3: Ablation Studies. We evaluate LiMA across three dimensions: architecture components, denoising steps, and system ratios ( Nslow:Nfast ). S.R.: Success Rate, Time: Inference Latency.
Appendix figures & tables6 assets
Supplementary material from the paper’s appendix.
Appendix
Figure 6: Overview of the real-world bimanual manipulation platform. The system consists of two UR5 robotic arms equipped with SharpaWave dexterous hands, a three-view RealSense D435 camera setup with one head-mounted camera and two wrist-mounted cameras, and a wearable teleoperation interface based on VIVE Trackers and MetaGlove Pro gloves for expert demonstration collection.
Figure 7: Visualization of task progress.
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
–
–
Appendix
Table 4: Progress stage definitions for real-world tasks. Each task is decomposed into several progress stages for computing Progress Success Rate (PSR).
Figure 8: Visualization of Dreamer & Refiner Generations.
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
Appendix
Table 5: Per-stage success rates for progress evaluation. We report the success rate of each progress stage to analyze where different methods fail during task execution.