Vision-language-action (VLA) models handle long-horizon manipulation, yet success hinges on a few precision-critical phases where millimeter-scale errors undo all prior progress. Online reinforcement learning (RL) can optimize exactly these actions, but free exploration is far too costly on real robots, which makes human corrections indispensable. However, existing online RL methods for VLAs either cannot incorporate such corrections or fold them into undifferentiated supervision. Yet human corrections are not uniformly noisy but reliable along some action dimensions and variable along others. Building on this, we introduce BEE, an intervention-adaptive framework for real-world RL on a frozen VLA that lets the policy go BEyond Expert imitation. We formulate human corrections not as actions to reproduce but as evidence about a constraint: a Correction Model predicts how a human would correct a given VLA proposal and how consistent the correction is along each action dimension. This predicted consistency sets the per-dimension tightness of a constraint on policy optimization. Where corrections are consistent the policy stays close to the human, and where they vary, the constraint relaxes. We evaluate BEE on three real-world manipulation tasks and one LIBERO-Pro simulation task at a matched online-data budget. BEE attains the highest success rate on every task, 91.2% on average against 57.5% for RLT and 42.1% for DSRL, and the lowest human intervention rate on all real-world tasks.
Figures & tables
Method
Phone Charging
Snack Hanging
Cloth Aligning
Bowl Placing
Overall
SR ↑
Int. ↓
SR ↑
Int. ↓
SR ↑
Int. ↓
SR ↑
Int. ↓
SR ↑
Int. ↓
Base Policy
90.0 ± 5.0
–
0.0 ± 0.0
–
36.7 ± 7.6
–
28.3 ± 7.6
–
38.8
–
RLT
58.3 ± 2.9 †
22.5
21.7 ± 5.8
62.1
73.3 ± 7.6
85.3
76.7 ± 17.6
26.2
57.5
49.0
DSRL
93.3 ± 2.9
–
13.3 ± 2.9
–
31.7 ± 2.9
–
30.0 ± 5.0
–
42.1
–
Bee
100.0 ± 0.0
12.2
85.0 ± 0.0
17.0
90.0 ± 10.0
65.3
90.0 ± 13.2
27.4
91.2
30.5
TABLE I : Comparison of Bee with the Base Policy, RLT, and DSRL . Success rate (SR, %, ↑ ) and human intervention rate (Int., %, ↓ ) on the real-world tasks phone charging, snack hanging, and cloth aligning, and on the LIBERO-PRO simulation task bowl placing. The Base Policy and DSRL involve no online intervention, so no intervention rate is reported.
Fig. 2 : Evaluation Tasks. Keyframes of the three real-world tasks (phone charging, snack hanging, cloth aligning) and of the LIBERO-PRO simulation task, bowl placing.
Fig. 3 : Sample Efficiency on Phone Charging and Snack Hanging . Success rate against the number of online robot episodes, with color distinguishing Bee from RLT and line style distinguishing the two tasks; the horizontal dashed lines mark the Base Policy. The right end of the axis is the matched online-data budget at which Table I is reported. Bee stays above RLT at every budget on both tasks.
Fig. 4 : Correction Model Calibration on Phone Charging , evaluated on human-intervention demonstrations over the seven joint dimensions q1 – q7 of the intervened arm. (a) The VLA proposal a~t and the corrected action a^tH produced by the Correction Model, plotted against the human correction. Points closer to the y=x line match it better. (b) Per-dimension root-mean-square error to the human correction. The corrected action reduces this error below the VLA proposal in every dimension. (c) Predicted per-dimension standard deviation of the Correction Model and empirical standard deviation of human corrections. The prediction follows the same per-dimension pattern as the empirical spread.
Fig. 5 : Dimension-wise Constraint Allocation on Phone Charging . Bars show each dimension’s constraint share (its normalized contribution to ρϕ ), and the overlaid curve is the predicted uncertainty σ of the Correction Model. (a) The state-wise form weights all dimensions equally, so a high-uncertainty dimension such as q5 claims the largest share. (b) The Mahalanobis form concentrates the share on low-uncertainty, consistently corrected dimensions (e.g., q2 ) and downweights high-uncertainty ones (e.g., q5 ).
Fig. 6 : Ablation of Human Correction Modeling on (a) phone charging and (b) snack hanging, each reporting success rate (left) and human intervention rate (right) for w/o VLA Proposal in Correction Model (the Correction Model conditioned on st alone), w/o Correction Model (direct actor supervision from raw human corrections), w/o Mahalanobis Constraint (a single state-wise constraint in place of the dimension-wise one), w/o Encoder (mean-pooled frozen VLA features in place of the latent-token encoder), and Bee .
Fig. 7 : Training Dynamics of the State-Dependent Multiplier on phone charging. (a) State-wise multiplier statistics. (b) Constraint slack and violation rate. (c) Per-dimension contributions to ρϕ .
Phone charging
Snack hanging
Cloth aligning
Bowl placing
Environment
real
real
real
LIBERO-Pro
Control rate
30 Hz
30 Hz
30 Hz
20 Hz
Action dims d / D
16 / 160
8 / 160
16 / 160
7 / 35
VLA chunk length (approach)
50
50
50
10
Learner chunk length K
10
20
10
5
Trained by online RL
critical phase
full task
critical phase
full task
TABLE II: Per-Task Specification. The action space lists the per-timestep dimension d and the chunked dimension D=Kd seen by the actor; the subset of dimensions online RL is allowed to edit, with the remaining dimensions held at the VLA proposal, is described in the text. On phone charging and cloth aligning online RL refines the precision-critical phase only, so an online episode covers that phase and success is reported on it. The online episode budget is the one given to the methods that are seeded with pre-collected human corrections. Section -D gives the budget of the methods that are not.
Hyperparameter
Value
Interface and action space
Control frequency
30 Hz
VLA chunk length, approach / online
50 / 10
Learner chunk length K
10
Per-timestep action dim. d
16
Chunked action dim. D=Kd
160
TABLE III : Hyperparameters of Bee on Phone Charging. Values are those of the run analyzed in the main paper; the quantities that vary by task are listed per task in Table II . All distances, thresholds, and noise scales are expressed in normalized action units.
Method
SR (%) ↑
Int. (%) ↓
Phone charging
Base Policy
90.0±5.0
–
DAgger
63.3±5.8
7.8
Bee
100.0±0.0
12.2
Bowl placing
SiLRI
0.0
90.0+
TABLE IV : Comparison with DAgger, SiLRI, and HIL-SERL under the matched robot-data budget. Each method is evaluated on the task where the comparison is informative. Intervention rates follow the accounting in Section -D and are not directly comparable across methods.
Vision-language-action (VLA) models can learn to perform diverse manipulation skills "out of the box," but achieving the precision and speed that real-world tasks demand requires further fine-tuning -- for example, via reinforcement learning (RL). We introduce a lightweight method that enables sample-efficient online RL fine-tuning of pretrained VLAs using just a few hours of real-world practice. We (1) adapt the VLA to expose an "RL token," a compact readout representation that preserves task-relevant pretrained knowledge while serving as an efficient interface for online RL, and (2) train a small actor-critic head on this RL token to refine the actions, while anchoring the learned policy to the VLA. Online RL with the RL token (RLT) makes it possible to fine-tune even large VLAs with RL quickly and efficiently. Across four real-robot tasks (screw installation, zip tie fastening, charger insertion, and Ethernet insertion), RLT improves the speed on the hardest part of the task by up to 3x and raises success rates significantly within minutes to a few hours of practice. It can even surpass the speed of human teleoperation on some of the tasks.
Charles Xu, Jost Tobias Springenberg, Michael Equi +4
Vision--language--action (VLA) models provide strong priors for robotic manipulation but are typically deployed as frozen policies, unable to improve from their own failures. Real-world reinforcement learning (RL) offers a path to continued improvement, yet manual environment resets and task-success supervision hinder autonomous learning. We introduce FIND, an agentic real-world RL framework that closes the loop between scene understanding, weakness-aware practice, self-evaluation, and policy improvement in a persistent workspace. FIND reframes autonomous practice as a scene-conditioned, performance-aware task-selection problem: instead of restoring a predefined scene after each rollout, it uses the resulting scene to determine what to practice next. A vision--language agent identifies feasible tasks from a predefined library, prioritizes those with lower recent success rates, and evaluates outcomes using paired pre- and post-execution observations. We instantiate FIND with a frozen π0.5 VLA and residual off-policy RL. Across eight real-world manipulation tasks, the independent human-assessed success rate improves from 55% to 71.9%. A representative run completes 456 autonomous episodes within 6 hours of interaction, requiring 30 scene-recovery interventions and no human-provided reward labels during online learning. Ablations and systematic evaluations further examine key design choices, agent evaluation accuracy, and human intervention requirements. Our website is made publicly available at: FIND.github.io.
Yuan Fang, Zechu Li, Haolei Tong +2
TU Darmstadt · University of Augsburg · Tongji University +1
Human interventions provide crucial corrective signals for post-training Vision-Language-Action (VLA) models. However, enabling seamless humanoid interventions is a formidable systems challenge due to complex whole-body kinematics and dexterous-hand control. Consequently, the collected intervention trajectories are often suboptimal, and methods that rely on human interventions as expert supervision can absorb hesitant, inefficient, or even erroneous behaviors. To address both the system and algorithmic challenges, we propose ROVE, a reinforcement learning framework for humanoid VLA post-training with imperfect human interventions. First, ROVE introduces a human-in-the-loop pipeline capable of collecting deployment and intervention data for humanoid manipulation. Second, it utilizes Optimistic Value Estimation (OVE) to prioritize high-value behaviors from mixed-quality trajectories. To further robustify value estimation, we incorporate cross-embodiment human experience videos to provide rich supervision for long-tailed failure and recovery modes. The resulting critic yields informative advantage signals, steering the VLA actor to focus on high-value behaviors rather than indiscriminately imitating all actions. On challenging real-world contact-rich and fine-grained humanoid manipulation tasks, ROVE outperforms experience-learning baselines and consistently improves across multiple rollout-intervention iterations.
Wei Xiao, Weiliang Tang, Yuying Ge +4
1XPENG Robotics · 2Fudan University · 3The Chinese University of Hong Kong +1