Speedup Patch: Learning a Plug-and-Play Policy to Accelerate Embodied Manipulation
Authors: Zhichao Wu, Junyin Ye, Zhilong Zhang, Yihao Sun, Haoxin Lin, Jiaheng Luo, Haoxiang Ren, Lei Yuan, Yang Yu
Organizations: National Key Laboratory for Novel Software Technology, Nanjing University, China · School of Artificial Intelligence, Nanjing University, China · Mila-Quebec AI Institute & Université de Montréal, Canada
While current embodied policies exhibit remarkable manipulation skills, their execution remains unsatisfactorily slow as they inherit the tardy pacing of human demonstrations. Existing acceleration methods typically require policy retraining or costly online interactions, limiting their scalability for large-scale foundation models. In this paper, we propose Speedup Patch (SuP), a lightweight, policy-agnostic framework that enables plug-and-play acceleration using solely offline data. SuP introduces an external scheduler that adaptively downsamples action chunks provided by embodied policies to eliminate redundancies. Specifically, we formalize the optimization of our scheduler as a Constrained Markov Decision Process (CMDP) aimed at maximizing efficiency without compromising task performance. Since direct success evaluation is infeasible in offline settings, SuP introduces World Model based state deviation as a surrogate metric to enforce safety constraints. By leveraging a learned world model as a virtual evaluator to predict counterfactual trajectories, the scheduler can be optimized via offline reinforcement learning. Empirical results on simulation benchmarks (Libero, Bigym) and real-world tasks validate that SuP achieves an overall 1.8x execution speedup for diverse policies while maintaining their original success rates.
Figures & tables
Figure 1: Plug-and-Play Speedup via Scheduler Policy. The scheduler policy π predicts a downsampling rate k to downsample the action chunk from the frozen policy into a shorter chunk for acceleration.
Figure 2: Success rate and Violation count. Each subplot (a–d) illustrates the relationship between the cumulative count of violations ( hE=1 ) and the task success rate across different LIBERO suites. The bars represent the conditional success rate for the subset of trajectories containing at least x violations, with the sample size of each subset annotated above the corresponding bar.
Figure 3: The training process of SuP. Our method is trained purely on offline datasets through three phases: (1) recurrent world model learning; (2) data synthesis; and (3) scheduler optimization via IQL. Through this pipeline, we optimize the scheduler to achieve the maximum possible speedup while preserving comparable performance.
Figure 4: Simulation Tasks. We systematically evaluate SuP across 20 tasks from Bigym and 4 task suites (40 tasks in total) from Libero.
Method
Sandwich Remove
Take Cups
Put Cups
Drawers Close All
(15 more tasks) …
Cupboards Close All
Average
ACT
-base
0.45, 340.5
0.15, 288.3
0.28, 320.3
1.0, 100.0
…
1.0, 449.8
0.66, 1.00 ×
-ds2
0.48, 186.3
0.13, 178.0
0.36, 175.9
1.0, 52.0
…
1.0, 234.0
0.61, 1.65 ×
+ DemoSpeedup
0.56, 171.5
0.10, 183.9
0.33, 169.3
1.0, 54.0
…
1.0, 202.1
0.61, 2.21 ×
+ SuP(Ours)
0.64 , 155.9
0.20 , 176.6
0.38 , 156.0
1.0, 40.0
…
1.0, 212.1
0.67 , 2.01 ×
DP
-base
0.40, 376.8
0.07, 284.6
0.28 , 307.7
0.66, 118.9
…
0.90, 544.0
0.51, 1.00 ×
-ds2
0.40, 209.6
0.12, 218.0
0.22, 181.5
0.54, 64.9
…
0.75, 270.3
0.40, 1.42 ×
Table 1: SuP speedup results on Bigym Tasks compared with baselines. Each cell in the table reports two metrics: the success rate followed by the average steps to completion, where only successful trajectories are counted. Higher success rates and lower step counts indicate better performance. Cells highlighted in orange denote the best success rate for each task, while those in gray indicate a performance drop exceeding 5% compared to the best success rate. 4 task results are shown, see all task results in App. C .
Method
Spatial
Long
Goal
Object
Average
π0.5
-base
0.988 , 105.3
0.924, 267.9
0.980, 113.1
0.982, 138.1
0.969, 1.00 ×
-ds2
0.914, 67.9
0.874, 153.4
0.952, 67.6
0.970, 75.0
0.928, 1.72 ×
+ DemoSpeedup
0.964, 88.1
0.932, 221.4
0.968, 88.7
0.988, 114.1
0.963, 1.22 ×
+ SuP(Ours)
0.972, 70.4
0.940 , 215.2
0.986 , 93.4
0.994 , 83.0
0.973 , 1.35 ×
VLA- Adapter
-base
0.922 , 99.6
0.936 , 255.1
0.970 , 107.0
0.942, 136.2
0.942 , 1.00 ×
-ds2
0.802, 57.1
0.834, 147.6
0.930, 57.1
0.882, 76.3
0.862, 1.77 ×
Table 2: SuP speedup results on Libero compared with baselines. Each cell in the table reports two metrics: the success rate followed by the average steps to completion, where only successful trajectories are counted. Higher success rates and lower step counts indicate better performance. Cells highlighted in orange denote the best success rate for each task, while those in gray indicate a performance drop exceeding 1% compared to the best success rate.
Method
Training Params
Training Time
Inference Overhead
DemoSpeedup
4B
20h
-
SuP (Ours)
5.12M
2h
1ms (2%)
Table 3: Computational Efficiency of SuP in Libero.
Figure 5: Real-world Tasks Illustration. We illustrate the procedure of 3 real-world tasks: (a) Arange Table (b) Fold Towel (c) Stack Plates .
Method
Arrange Table
Fold Towel
Stack Plates
Average
π0.5
-base
11/30, 537.8
15/30, 519.5
27/30, 221.5
0.589, 1.00 ×
+ ds2
10/30, 291.9
14/30, 326.3
27/30, 177.1
0.567, 1.61 ×
+ ds3
3/30, 247.2
8/30, 187.7
21/30, 148.4
0.356, 2.19 ×
+ DemoSpeedup
12/30, 267.4
14/30, 223.2
28/30 , 124.4
0.600, 2.07 ×
+ SuP(Ours)
13/30 , 258.5
16/30 , 192.5
26/30, 138.5
0.611 , 2.17 ×
Table 4: SuP speedup results on Real-world Tasks compared with baselines.
Figure 6: Case study. We visualize the adaptive downsampling strategy during a Fold Towel task. The plot tracks the predicted downsampling rate over the episode timesteps. Shaded regions annotate distinct task phases.
Figure 7: Comparison between ADM-based and MLP-based world model. (a) Visualization of task success rates against predicted violation counts in the Spatial suite. (b) Spearman correlation scores across four LIBERO suites.
Ablation
Sandwich Remove
Put Cup
Long
πbase
0.45, 340.5
0.28, 320.3
0.924, 267.9
SuP-0.01
0.59, 187.5
0.35, 159.8
0.940 , 215.2
SuP-0.015
0.64 , 155.9
0.38 , 156.0
0.922, 191.8
SuP-0.02
0.46, 157.6
0.21, 143.3
0.904, 168.4
MPC-0.01
0.54, 181.4
0.32, 154.8
0.936, 225.2
MPC-0.015
0.59, 173.3
0.3, 146.1
0.924, 205.6
Table 5: Ablation study on SuP. We compare the performance impact of the IQL module and different deviation thresholds ϵ .
Appendix figures & tables10 assets
Supplementary material from the paper’s appendix.
Appendix
Method
Sandwich Remove
Take Cups
Put Cups
Dishwasher Open Trays
Move Plate
ACT
-base
(0.45, 340.5)
(0.15, 288.3)
(0.28, 320.3)
( 1.0, 275.0)
( 0.58 , 194.8)
-ds2
(0.48, 186.3)
(0.13, 178.0)
(0.36, 175.9)
( 1.0, 169.0)
(0.50, 155.0)
+ DemoSpeedup
(0.56, 171.5)
(0.10, 183.9)
(0.33, 169.3)
(1.0, 156.0)
(0.28, 71.7 )
+ SuP(Ours)
( 0.64 , 155.9 )
( 0.20 , 176.6 )
( 0.38 , 156.0 )
(1.0, 131.0 )
(0.49, 167.2)
DP
-base
(0.40, 376.8)
(0.07, 284.6)
( 0.28 , 307.7)
(0.57, 351.2)
(0.33, 261.1)
-ds2
(0.40, 209.6)
(0.12, 218.0)
(0.22, 181.5)
(0.48, 310.2)
(0.36, 203.3)
Appendix
Table 6: Performance comparison of different methods in all Bigym tasks. Best success rates and shortest lengths are bolded . Method with best success rate per task is highlighted .
Table 7: Hyperparameters for ACT and DP in Bigym.
Figure 8: ARX5 illustration. (a) The master-follow design for data collection (b) The actual scene of our real-world experiment.
Method
spatial
long
goal
object
Average
π0.5 (Original)
0.988, 105.3
0.924, 267.9
0.980, 113.1
0.982, 138.1
0.969, 1.00 ×
No Grip Fix (-ds2)
0.708, 77.0
0.818, 167.4
0.888, 66.2
0.954, 84.4
0.842, 1.58 ×
With Grip Fix (-ds2)
0.914, 67.9
0.874, 153.4
0.952, 67.6
0.970, 75.0
0.928, 1.72 ×
Appendix
Table 8: Ablation study of gripper action compensation on Libero benchmarks. We compare the original policy ( pi0.5 ) with downsampled versions ( N=2 ) before and after applying the gripper fix.
Figure 9: Network architecture of Recurrent World Model and Scheduler Policy.
Hyperparameter
BiGym
Libero
Real-world
Learning rate
3×10−4
1×10−4
1×10−4
Batch size
512
512
512
GRU hidden dimension
256
256
256
GRU layers
3
3
3
Chunk length
24
10
20
kmin
2
1
2
Appendix
Table 9: Hyperparameter configurations of SuP in different experiment settings.