Online reinforcement learning (RL) enables robot policies to improve through physical interaction, but the assistance they require changes as their competence evolves. Existing intervention strategies based on offline estimates or fixed decision rules can therefore become mismatched to the current policy. To address this, we propose UniIntervene++, an adaptive intervention agent that learns to allocate control between autonomous execution and heterogeneous assisted behaviors during online RL. Specifically, UniIntervene++ first formulates the evolving RL policy, trajectory correction, and a task-structured CodePolicy as Options in a unified semi-Markov decision process and learns their relative values online. Building on this, competence-adaptive intervention periodically probes the RL policy through unassisted execution, keeping control allocation responsive to its evolving capability. Finally, coupled experience learning allows assisted behaviors to improve the RL policy, whose evolving outcomes in turn reshape future intervention decisions. In this way, UniIntervene++ jointly determines when to intervene, how to intervene, and when to return control as the RL policy improves. Across five real-world manipulation tasks, UniIntervene++ achieves an average success rate of 89.67%, outperforming all baselines by at least 6 percentage points, while reducing human intervention to 0.77%, a relative reduction of at least 94.6% from the best baseline. Code is available in our GitHub repository.
Figures & tables
Fig. 1: Competence-adaptive control allocation in UniIntervene++ . Illustrative Ring Transfer rollouts show a shift from early failures with substantial use of Trajectory Correction and CodePolicy to later autonomous success with predominantly RL policy control. Colored bars indicate Option occupancy within each rollout (teal: RL policy; orange: Trajectory Correction; purple: CodePolicy). Assisted experience improves the RL policy, while Adaptive RL Probe reserves unassisted windows to assess its evolving competence and guide subsequent allocation.
Fig. 2: Overview of UniIntervene++ . At each Option boundary, the availability-masked intervention agent selects among the evolving RL policy, trajectory correction, and CodePolicy. Robot-control transitions update the RL policy, while Option-completion transitions update the intervention agent. Adaptive RL Probe preserves direct evidence of the RL policy’s current competence.
Method
Pick and Place
Contact rich
Deformable Object
Average
Ring Transfer
Tube Insertion
USB Insertion
Wipe Whiteboard
Towel Folding
SR ↑
HIR ↓
SR ↑
HIR ↓
SR ↑
HIR ↓
SR ↑
HIR ↓
SR ↑
HIR ↓
SR ↑
HIR ↓
HIL-SERL
83.33
39.15
85.00
39.65
90.00
51.68
85.00
63.11
75.00
76.57
83.67
54.03
AutoSERL
53.33
17.07
80.00
0.10
88.33
3.91
80.00
16.80
66.67
33.55
73.67
14.29
UniIntervene
85.00
25.32
73.33
15.80
90.00
9.90
90.00
10.90
80.00
32.30
83.67
18.84
UniIntervene++
88.33
0.30
91.67
2.58
96.67
0.96
86.67
0.01
85.00
0.00
89.67
0.77
TABLE I: Real-world manipulation results across five tasks. Bold and underlined values indicate the best and second-best results, respectively; ties share the same formatting. Higher SR and lower HIR are better.
Fig. 3: UR7e setup for five manipulation tasks.
Fig. 4: TCP trajectories stored in the replay buffers during the USB Insertion task. Blue and red curves denote successful and failed trajectories, respectively; green circles and black crosses indicate the start and end points. Numbers in parentheses report the number of trajectories in each outcome category.
Fig. 5: Task-wise intervention decomposition across five real-world manipulation tasks. IR denotes the fraction of training steps executed under automated or human intervention, while HIR denotes the subset executed under human control. The automated-intervention share is (IR−HIR)/IR . Arrows indicate the preferred direction.
Fig. 6: Visualization and comparison on the Ring Transfer task. From the same initial state, AutoSERL fails to complete the transfer, whereas UniIntervene++ completes the task through adaptive control allocation between autonomous execution and assisted behaviors. This illustrates how competence-adaptive intervention improves robust execution.
Fig. 7: Duration-weighted control allocation among the three Options and RL policy success evaluated at multiple checkpoints during Ring Transfer training. Within each time window, the control share of an Option is computed as its accumulated execution duration divided by the total execution duration of all three Options. The lower rows show representative execution sequences of the RL policy (circle), CodePolicy (square), and Trajectory Correction (triangle).
Training configuration
Ring Transfer
Towel Folding
SR(%)
SR(%)
SERL
0
0
w/o CodePolicy
0
0
w/o Trajectory Correction
50
47
Fixed-prior stochastic scheduler
75
80
UniIntervene++
88.33
85
TABLE II: Ablation Study on Ring Transfer and Towel Folding
Human-in-the-loop reinforcement learning (HiL-RL) has emerged as an effective paradigm for real-world robotic manipulation, enabling online policy improvement with human guidance. However, current HiL-RL frameworks remain intervention-intensive, relying on frequent human corrections to redirect the policy out of unproductive exploration, which incurs high labor cost and limits real-world scalability. To address this, we propose UniIntervene, an agentic intervention model that detects unproductive exploration and autonomously recovers the policy toward high-value states, taking over the bulk of interventions from human operators. Specifically, UniIntervene first performs future-conditioned action-value estimation, predicting the latent consequence of the current action and evaluating its induced value, which provides a more stable progress signal. Building on this, a temporal value-risk critic aggregates recent value dynamics and triggers intervention when the estimated value exhibits sustained stagnation or degradation. When intervention is required, UniIntervene retrieves a high-value recovery target from a memory of past intervention episodes and produces executable corrective actions through a goal-conditioned recovery policy. In this way, UniIntervene turns intervention from passive human correction into a value-aware recovery process for efficient real-world RL. Extensive experiments on diverse real-world manipulation tasks demonstrate that UniIntervene improves the average success rate by 8.6% while reducing human interventions by 57% relative to state-of-the-art HiL-RL baselines.
Haoyuan Deng, Yitong Gao, Yudong Lin +3
Nanyang Technological University · Beijing University of Posts and Telecommunications
Correcting robot manipulation policies through human intervention holds great promise for real-world deployment, yet human operators are inherently imperfect in both the actions they provide and the timing of their intervention signals. While the former has been extensively discussed in reinforcement learning (RL), the latter remains underexplored. At high control frequencies, human intervention signals are often delayed and inconsistent across time and state space. In this work, we present GAINS, a framework for leveraging inconsistent human intervention signals in RL. At the core of GAINS, we employ distributional RL with quantile Q-networks to model the return variability induced by sparse task rewards and inconsistent human interventions. Building on this distributional representation, we introduce a pessimistic exploration strategy that promotes safe and sample-efficient learning under human corrections. We evaluate GAINS on four diverse simulated manipulation tasks and two challenging real-world scenarios against state-of-the-art intervention-based methods. GAINS achieves a 22% higher task success rate than RLIF and improves recovery success by up to 43% in failure scenarios. These results highlight the importance of modeling return variability induced by human imperfection for real-world deployment of intervention-based learning.
Xinyi Zhang, Yinuo Zhao, Pei Ren +7
Beijing Institute of Technology · Beijing Innovation Center of Humanoid Robotics · City University of Hong Kong +1
While reinforcement learning (RL) enables robots to acquire skills autonomously, its real-world deployment is severely limited by inefficient and unsafe exploration. Human-in-the-loop interventions offer a practical solution, yet existing methods typically exploit these interventions as auxiliary training signals, without fully capturing the richer information they provide about when and how autonomy should be guided. Human interventions often encode relative preferences over behavior under safety and task constraints, rather than prescribing exact actions to imitate. Motivated by this perspective, we propose Online Human Preference as Guidance in Reinforcement Learning (OHP-RL), a framework that leverages human interventions as preference information to guide policy learning. OHP-RL introduces a state-dependent preference gate that adaptively regulates when and to what extent human interventions should shape policy learning. This design enables the agent to benefit from intermittent and imperfect human feedback while preserving autonomous exploration and stable policy optimization. We evaluate OHP-RL on three challenging real-world contact-rich manipulation tasks on a Franka robot. Across all tasks, OHP-RL consistently achieves strong success rates, faster convergence, and substantially lower human intervention effort than prior approaches. Moreover, the learned policies exhibit more stable and human-aligned behavior throughout training.
Yunyang Mo, Jian Li, Qiwei Wu +2
The Hong Kong University of Science and Technology (Guangzhou)