This paper addresses a fundamental problem of visuomotor policy learning for robotic manipulation: how to enhance robustness in out-of-distribution execution errors or dynamically re-routing trajectories, where the model relies solely on the original expert demonstrations for training. We introduce the Referring-Aware Visuomotor Policy (ReV), a closed-loop framework that can adapt to unforeseen circumstances by instantly incorporating sparse referring points provided by a human or a high-level reasoning planner. Specifically, ReV leverages the coupled diffusion heads to preserve standard task execution patterns while seamlessly integrating sparse referring via a trajectory-steering strategy. Upon receiving a specific referring point, the global diffusion head firstly generates a sequence of globally consistent yet temporally sparse action anchors, while identifies the precise temporal position for the referring point within this sequence. Subsequently, the local diffusion head adaptively interpolates adjacent anchors based on the current temporal position for specific tasks. This closed-loop process repeats at every execution step, enabling real-time trajectory replanning in response to dynamic changes in the scene. In practice, rather than relying on elaborate annotations, ReV is trained only by applying targeted perturbations to expert demonstrations. Without any additional data or fine-tuning scheme, ReV achieve higher success rates across challenging simulated and real-world tasks.
Figures & tables
Figure 1: The role of the proposed Referring-Aware Visuomotor Policy (ReV) in mitigating out-of-distribution failures. In executing the task “Grabbing the steak from the kitchen table” , several challenges can be encountered. Case A : a small covariate shift at tk quickly leads to a compounding misalignment with expert demonstrations, driving the robot into unseen states and resulting in task failure. Case B : an unforeseen obstacle ( e . g ., a pot) emerges at tk to dynamically block the robot’s path, leading to failure as well. Unlike traditional imitation learning methods that often struggle to generalize to unseen states or observations, the proposed ReV employs coupled diffusion heads to online react to external sparse referring provided by a human or a high-level reasoning planner. Without requiring additional training data or complex fine-tuning in post-processing, the model can effectively address Case A and Case B in real-world applications.
Figure 2: Overview of our Referring-Aware Visuomotor Policy. Given the observation O and robot proprioception history A− , the Temporal-Position Prediction Module on the left assign the optimal temporal position k for the referring point P . This temporally-positioned referring point P is then transformed into a temporally-positioned partially-constrained referring action Pa (detailed in Sec. 3.3 ) and injected into the right Policy Model with Coupled Diffusion Heads to generate the final trajectory A satisfying the Manipulation Steering Choreography . Specifically, at step i , the GDH incorporates both anchor history A−′ and partially-constrained referring action Pa via the trajectory-steering strategy to yield a sparse yet globally consistent anchor sequence A′={aj′}j=1N1 , in which {aj′}j=1i−1 is anchor history A−′ , {aj′}j=ii+1 is interpolated by the LDH through a learnable, temporal-dependent interpolation strategy, and {aj′}j=i+1N1 is discarded and will be updated at upcoming inference step. At inference step i+1 , the anchor history A−′ is updated by appending the newly generated anchor ai+1′ at step i , and the entire policy model repeats, continuously updating A .
Figure 3: Temporal-Position Prediction . The slots buffer S covers both retained history and extrapolated future steps. Specifically, at step i , we load the historical action anchors {aj′}j=1i to initialize history part, and the future part is padded by copies of the last action anchor ai′ . Then, the whole slots buffer is augmented with a monotonically-increasing temporal-position embeddings.
Method
Pick Meat-via
Lift Barrier-via
Place Food-via
Camera Alignment-via
RePR( ↑ )
SuR( ↑ )
SmS( ↑ )
RePR( ↑ )
SuR( ↑ )
SmS( ↑ )
RePR( ↑ )
SuR( ↑ )
SmS( ↑ )
RePR( ↑ )
SuR( ↑ )
SmS( ↑ )
ACT
2%
1%
0.9890
1%
1%
0.9904
0%
0%
-
0%
0%
-
DP3
80%
1%
0.9899
99%
25%
0.9945
1%
1%
0.9883
0%
0%
-
CDP
14%
14%
0.9924
99%
99%
0.9933
47%
33%
0.9878
0%
0%
-
OCTO
18%
9%
0.9606
32%
32%
0.9702
1%
1%
0.9597
0%
0%
-
MPD
20%
3%
0.9903
39%
39%
0.9949
3%
3%
0.9887
1%
1%
0.9861
Table 1: Quantitative results on modified simulated benchmark , highlighting the effectiveness of ReV in referring-aware manipulation.
Figure 4: Visualization of the trajectories generated by ReV on Pick-Meat-via and Lift-Barrier-via . Here, we use green bounding boxes to mark the frames in which the end-effector passes through the designated via-point (green ball).
Method
0.1
0.2
0.3
0.4
RePR( ↑ )
SuR( ↑ )
RePR( ↑ )
SuR( ↑ )
RePR( ↑ )
SuR( ↑ )
RePR( ↑ )
SuR( ↑ )
ReV
100%
93%
100%
92%
100%
89%
100%
87%
Table 2: Ablation study on OOD-yet-feasible referring points. 0.1, 0.2, 0.3, and 0.4 indicate the degree of deviation from the center of the expert distribution. Details are provided in Appendix B.4 .
Method
Adroit
DexArt
MetaWorld
RoboFactory
Pen
Door
Laptop
Toilet
Bucket
Reach
Soccer
Sweep Into
Shelf Place
Pick Meat
Lift Barrier
Place Food
Camera Alignment
ACT
47%
66%
35%
8%
6%
21%
28%
23%
43%
91%
40%
13%
21%
DP3
53%
69%
81%
65%
32%
28%
30%
15%
37%
81%
90%
30%
87%
CDP
68%
74%
84%
68%
32%
22%
23%
24%
35%
84%
93%
51%
90%
ReV
73%
79%
87%
71%
61%
36%
33%
27%
47%
94%
99%
57%
94%
Table 3: Quantitative results across simulated benchmarks , highlighting the effectiveness of our Coupled Diffusion Heads architecture.
Method
Single-Agent
Dual-Agent
Collecting Objects-via
Push T-via
Stacking Playing Card-via
Grabbing Rod-via
Handing Eraser Over-via
PeRP ↑
SuR ↑
PeRP ↑
SuR ↑
PeRP ↑
SuR ↑
PeRP ↑
SuR ↑
PeRP ↑
SuR ↑
ACT
3 / 30
1 / 30
5 / 30
3 / 30
3 / 30
0 / 30
2 / 30
0 / 30
3 / 30
1 / 30
DP
6 / 30
5 / 30
12 / 30
9 / 30
9 / 30
3 / 30
3 / 30
1 / 30
6 / 30
2 / 30
ReV
30 / 30
20 / 30
30 / 30
21 / 30
30 / 30
15 / 30
30 / 30
18 / 30
30 / 30
12 / 30
Table 4: Quantitative results on real-world tasks , highlighting the robustness of our ReV in real-world settings.
Appendix figures & tables10 assets
Supplementary material from the paper’s appendix.
Appendix
Figure 5: Demonstration Construction Strategy for GDH and LDH . The orange blocks represent the sparse action anchors. Among them, the lighter orange exemplifies the historical context, while the darker orange exemplifies the future targets. The green blocks denote the fine-grained interpolation actions.
Figure 6: Via-Points Generation. Via-points are generated via Gaussian sampling around a centroid derived from the robot’s initial configuration.
Figure 7: Visualization of ablation studies on key hyperparameters. (a) Total trajectory length N : performance peaks when N matches task complexity, enabling the model to capture task-specific execution patterns. (b) Trajectory-length allocation N1:N2 : balanced ratios ( 1:2∼2:1 ) allow our policy model to learn the entire trajectory most effectively. (c) Update Frequencies of T-P prediction : excessive updates cause anchor drift and degrade performance. Here, success rate is defined as the fraction of trials that simultaneously achieve task completion and pass through the designated referring point, and all ablations were conducted under controlled variables.
Method
Inside Camera
Inside Pot
Under Table
Out of Reach
DP3
0%
0%
0%
0%
CDP
0%
11%
0%
0%
ReV
100%
100%
0%
0%
Appendix
Table 5: Ablation study on infeasible referring points.
Table 6: All Training Settings for simulation experiments.
Benchmark
Task
N
N1
N2
Adroit
Door
54
6
12
Pen
70
6
16
Dexart
Bucket
11
3
8
Laptop
20
4
8
Toilet
70
6
16
MetaWorld
Shelf Place
11
3
8
Appendix
Table 7: Trajectory-Length Allocation for each task in simulation and real-world experiments.
Figure 9: Visualization of the trajectories generated by ReV on Place-Food-via and Camera-Alignment-via . Here, we use green bounding boxes to mark the frames in which the end-effector passes through the designated via-point (green ball).
Figure 10: Real-world Experimental Platform. The setup comprises a dual-robot arm system, a top-down RGB-D camera, and a black table serving as the workspace.
Task
Agent Number
Description
Collecting Objects
1
A doll is placed on the table. The robotic manipulator first grasps it and then transports it into the green box.
Push T
1
A T-shaped object is initially positioned on the table. The robotic arm pushes it into a predefined T-shaped location.
Stacking Playing Card
1
A playing card is placed flat in the central region of the table. The robotic arm first grasps it precisely and then places it vertically into another playing card to achieve a stacking effect.
Grabbing Rod
2
A long rod is placed on a block. The two robotic arms first simultaneously grasp each end of the rod and then collaboratively lift it to a specified height.
Handing Eraser Over
2
One robotic arm first grasps an eraser precisely. It then passes the eraser to another robotic arm through a coordinated handover motion.
Appendix
Table 8: Original Task Descriptions for real-world experiments.
Visuomotor policy learning trains robots to turn camera observations, often with language and proprioception, into actions for manipulation and navigation.
School of Future Science and Engineering, Soochow University · Key Laboratory of General Artificial Intelligence and Large Models in Provincial Universities, Soochow University · College of Mechanical and Electronic Engineering, China Jiliang University +2