Scaling Online Exploration for Robot Agents
Organizations: Harvard University · NVIDIA · UC Berkeley · Stanford University ·
Abstract
Robot learning has advanced by scaling demonstration datasets and model capacity; however, deploying a new robot embodiment or task typically necessitates a dedicated teleoperation corpus. The resulting policies remain bounded by their imitation distributions, limiting generalization and continual self-improvement. We introduce RAX (Robot Agent eXploration), an open-source framework for robot agents centered on scaling exploration: enabling agents to improve by acquiring online experience and synthesizing executable programs. In RAX, a general-purpose coding agent generates robot control code, operating without action demonstration data, hand-engineered action primitives, or value-function guidance. Through online exploration, the agent identifies decision sequences that achieve task goals and compiles them into modular programs encapsulating the full perception-planning-control loop. Using RAX, we present a systematic multi-embodiment study on scaling online exploration across precision and long-horizon manipulation tasks using single-arm, bimanual, dexterous, mobile, and humanoid systems in simulation and on real robots. Generalization performance on unseen environments improves consistently as exploration scales. In simulation, RAX outperforms top baseline models by +37.4% on average. On real robots, RAX autonomously learns memory-dependent, articulated, high-precision, deformable, and long-horizon mobile manipulation tasks without human demonstrations, continually improving performance by composing verified skills from prior exploration sessions. As exploration scales, we observe emergent capabilities including active perception, error recovery, safety guardrails, and human-robot collaboration. We open-source RAX as a generalist robot-agent platform in which new robot embodiments are integrated through their APIs alone, without teleoperated data collection or policy training.
Figures & tables
| Platform | Low-level control | Agent action space | Model-based helpers |
|---|---|---|---|
| LIBERO, LIBERO-Pro single-arm Franka Panda | EEF pose control (OSC) | EEF position and rotation deltas; gripper command | Pixel-to-3D projection from depth |
| RoboDojo dual-arm ARX X5 | Joint position control (PD) | Joint-target chunks for both arms and grippers; bounded EEF steps | Forward kinematics, differential IK, pose algebra, collision-aware motion planning, robot-only preview |
| DexJoCo Franka Panda + Allegro hands | Arm: EEF pose control (OSC); hand: joint position control | Flange pose and sixteen hand joint targets per arm, single- or dual-arm | Pixel-to-3D projection from depth, robot-only preview |
| BEHAVIOR-1K Galaxea R1Pro | Base velocity control; trunk and arm joint position control | Base velocity, trunk and arm joint targets, grippers; closed-loop base moves from odometry | Closed-loop arm IK, arm and trunk motion planning, robot-only preview |
| HumanoidArena Unitree G1 + Dex3 | Whole-body motion tracker | Whole-body reference frames: heading, 29 joint targets, hand open or close | Arm and waist motion planning to hand poses; kinematic model for forward kinematics and image projection |
| Franka FR3 real | Joint impedance control | Straight-line EEF moves, joint moves, force-controlled grasps | Inverse kinematics; path checks against workspace and table |
| Make toast | Hang mugs | Sweep blocks | Plug | Swap | Make | Pour by | ||
| Method | Budget | random | random | random | charger | blocks | kong | language |
| VPP2 | – | 38.0 | 13.5 | 1.3 | 16.7 | 26.0 | 78.7 | 0.0 |
| Awomo-0.5 | – | 7.0 | 9.6 | 0.0 | 7.3 | 4.7 | 30.0 | 0.0 |
| Simate-beta | – | 7.7 | 11.4 | 0.0 | 29.3 | 38.7 | 76.0 | 0.0 |
| Rex-M1 Preview | – | 14.3 | 20.2 | 8.0 | 3.3 | 13.3 | 33.3 | 0.0 |
| VPP2-Preview | – | 13.7 | 14.5 | 2.7 | 6.0 | 22.7 | 34.7 | 0.0 |
| Boxing | Getting | Sorting | Clearing | Clean up | Loading | ||
|---|---|---|---|---|---|---|---|
| Method | books | organized | items | food | desk | the car | Avg. |
| Robot Learning Collective | 0.0 | 2.0 | 6.2 | 8.0 | 12.7 | 20.0 | 8.2 |
| Comet | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| SimpleAI Robot | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| The North Star | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 20.0 | 3.3 |
| Embodied Intelligence ‡ | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Human–object interaction | Human–scene interaction | |||||||||
| Method | Demos | Budget | Football | DoubleDesk | P&PBox | OpenDoor | SitSofa | Boxing | VisNavi | Avg. |
| ACT | 100 | – | 16.7 | 18.3 | 56.7 | 78.3 | 73.3 | 56.7 | 33.3 | 47.6 |
| Diffusion Policy | 100 | – | 45.0 | 36.7 | 75.0 | 85.0 | 78.3 | 76.7 | 23.3 | 60.0 |
| Flow matching | 100 | – | 13.3 | 38.3 | 73.3 | 70.0 | 15.0 | 70.0 | 38.3 | 45.5 |
| 100 | – | 10.0 | 43.3 | 71.7 | 66.7 | 73.3 | 70.0 | 23.3 | 51.2 | |
| WB-WAM | 100 | – | 70.0 | 65.0 | 86.7 | 98.3 | 95.0 | 81.7 | 76.7 | 81.9 |
| Single-arm | Bimanual | ||||||||||||
| Method | Budget | Hammer | Mouse | Bucket | Tongs | Glasses | Water | iPad | Hanoi | Assembly | Microwave | Photo | Avg. |
| DP-T | – | 81.3 | 62.0 | 83.3 | 22.7 | 53.3 | 84.0 | 8.0 | 24.7 | 4.7 | 73.3 | 56.7 | 50.4 |
| DP-C | – | 58.7 | 74.0 | 70.0 | 57.3 | 54.0 | 63.3 | 52.0 | 12.7 | 3.3 | 54.0 | 24.0 | 47.6 |
| ACT | – | 50.0 | 61.3 | 64.0 | 31.3 | 47.3 | 47.3 | 9.3 | 6.0 | 0.0 | 66.0 | 7.3 | 35.5 |
| – | 84.7 | 64.7 | 84.0 | 24.0 | 72.0 | 88.7 | 36.0 | 23.3 | 2.7 | 60.0 | 54.7 | 54.1 | |
| GR00T N1.5 | – | 67.3 | 85.3 | 72.0 | 12.7 | 27.3 | 72.7 | 12.7 | 0.7 | 0.7 | 50.7 | 40.7 | 40.2 |
| LIBERO | LIBERO-Pro, position perturbation | ||||||||||
| Method | Demos | Spatial | Object | Goal | Long | Avg. | Spatial | Object | Goal | Long | Avg. |
| OpenVLA | 50 | 84.7 | 88.4 | 79.2 | 53.7 | 76.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| OpenVLA-OFT | 50 | 97.6 | 98.4 | 97.9 | 94.5 | 97.1 | – | – | – | – | – |
| 50 | 96.8 | 98.8 | 95.8 | 85.2 | 94.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
| 50 | 98.8 | 98.2 | 98.0 | 92.4 | 96.9 | 20.0 | 17.0 | 38.0 | 8.0 | 20.8 | |
| X-VLA | 50 | 98.2 | 98.6 | 97.8 | 97.6 | 98.1 | 0.0 | 2.0 | 1.0 | 0.0 | 0.8 |
| Agent | Agents | Envs | Budget | Time (h) | Success | Score |
|---|---|---|---|---|---|---|
| Codex | 1 | 1 | 32 | 14.2 | 40.6 | 66.4 |
| Codex | 2 | 2 | 32 | 9.2 | 56.3 | 65.6 |
| Claude Code | 1 | 1 | 48 | 13.7 | 50.0 | 63.3 |
| Claude Code | 4 | 4 | 32 | 4.9 | 87.5 | 92.2 |
| Task | Budget | RGB-D | RGB-only | |
|---|---|---|---|---|
| Make toast random | 16 | 2.5 | 0.0 | 2.5 |
| Make toast random | 32 | 31.7 | 7.8 | 23.9 |
| Hang mugs random | 16 | 36.9 | 13.9 | 23.0 |
| Sweep blocks random | 16 | 53.3 | 33.3 | 20.0 |
| Average | 31.1 | 13.8 | 17.3 |
| Task | Actions from | Inference | Robot time | Output tokens |
|---|---|---|---|---|
| Air fryer | Agent | 72.3 min | 2.9 min | 262.4 k |
| Program | 18 s | 2.5 min | 2.0 k | |
| Bandu tower | Agent | 17.2 min | 9.3 min | 88.4 k |
| Program | 10 s | 10.9 min | 2.2 k |
| Method | Demos | Budget | Football | DoubleDesk | P&PBox | OpenDoor | SitSofa | Boxing | VisNavi | Avg. |
|---|---|---|---|---|---|---|---|---|---|---|
| WB-WAM | 100 | – | 70.0 | 65.0 | 86.7 | 98.3 | 95.0 | 81.7 | 76.7 | 81.9 |
| RAX | 3 | 32–128 | 98.3 | 56.7 | 83.3 | 100.0 | 96.7 | 100.0 | 93.3 | 89.8 |
| RAX ⋆ | 3 | 64–256 | 98.3 | 46.7 | 70.0 | 95.0 | 100.0 | 86.7 | 76.7 | 81.9 |
| Franka FR3 | Rainbow RB-Y1 | |
|---|---|---|
| Perception | RGB-D images from two exterior and one wrist camera; pixel to 3D point | Head RGB-D images and gaze control; pixel to 3D point; a vision-language model |
| Motion | Straight-line end-effector moves; joint moves with path checks | Joint, end-effector, and torso targets; IK over torso and both arms; base drive |
| Gripper | Grasp to a width with a set force | Close with a current limit, or set an opening |
| Model | None (the agent writes its own kinematics) | Forward kinematics; dry runs for collision, joint load, and center of mass |
| Skill | What it asks of the agent |
|---|---|
| Manual robot control | Look first, explore with small moves, choose each action from the current observation, and confirm every condition of the task before handing off. |
| In-context action learning | When images of a completed task are supplied, infer the goal and useful strategy from them and adapt it to the current layout, without copying actions. |
| Experience memory | Record what worked right away, with the observable conditions under which it worked; retrieve it for similar situations and distill it as evidence grows. |
| Autonomous control | Start from a confirmed manual success, turn it into observation-driven code that can be supervised and resumed, and test it across layouts. |
| Transfer hand-off | Before exploration ends, write how each subtask and each object is handled, for a later session on new layouts. |
| Multi-environment exploration | Run parallel environments, track their scenes separately, and share one episode budget. |
| Task | Benchmark id | Step limit | Partial credit | Evaluation | Agent |
|---|---|---|---|---|---|
| Make toast random | make_toast_random | 1400 | 25/50/100 | 45 | Codex |
| Hang mugs random | hang_mugs_random | 800 | 15/40/100 | 50 | Claude Code |
| Sweep blocks random | sweep_blocks_random | 1000 | – | 30 | Codex |
| Plug in charger | plug_in_charger | 400 | – | 50 | Claude Code |
| Swap blocks | swap_blocks | 700 | – | 50 | Codex |
| Make kong | make_kong | 600 | – | 50 | Codex |
| Task | Benchmark id | Agent | Step limit | Budget | Envs | Program |
|---|---|---|---|---|---|---|
| Boxing books | boxing_books_up_for_storage | Codex † | 36,341 | 128 | 6 | fully automated |
| Getting organized | getting_organized_for_work | Claude Code ∗ | 23,506 | 128 | 2 | agent-in-the-loop |
| Sorting items | sorting_household_items | Claude Code | 23,711 | 128 | 8 | agent-in-the-loop |
| Clearing food | clearing_food_from_table_into_fridge | Claude Code | 19,602 | 128 | 4 | agent-in-the-loop |
| Clean up desk | clean_up_your_desk | Claude Code | 32,126 | 128 | 4 | agent-in-the-loop |
| Loading the car | loading_the_car | Claude Code ∗ | 28,839 | 128 | 2 | agent-in-the-loop |
| Task | Type | Step limit | Success condition | Budget |
|---|---|---|---|---|
| Football | HOI | 2000 | the ball passes the goal line between the posts | 32 |
| DoubleDesk | HOI | 2000 | the hammer rests inside the basket on the second desk | 128 |
| P&PBox | HOI | 1450 | the box rests on the shelf, inside its outline | 128 |
| OpenDoor | HSI | 1800 | the latch is released and the door is open by at least 60 ∘ , robot standing | 32 |
| SitSofa | HSI | 2000 | the pelvis is over the seat and below 0.66 m | 32 |
| Boxing | HSI | 900 | a palm comes within 0.18 m of the target on the bag | 32 |
| Task | Benchmark id | Arms | Cameras | Step limit |
|---|---|---|---|---|
| Hammer | hammer_nail | one | front, wrist | 1000 |
| Mouse | click_mouse | one | ego_right, wrist | 1200 ∗ |
| Bucket | pick_bucket | one | front, wrist | 1200 |
| Tongs | pinch_tongs | one | front, wrist | 1000 |
| Glasses | fold_glasses | one | front, wrist | 1200 |
| Water | water_plant | one | front, wrist | 1000 |
| Budget | Interactive | Rehearsal | Used / budgeted | Submitted early | Agent time (h) |
|---|---|---|---|---|---|
| 2 | 11 | 11 | 22 / 22 | 0 of 11 | 0.70 (0.44–1.28) |
| 4 | 26 | 18 | 44 / 44 | 0 of 11 | 1.05 (0.51–2.46) |
| 8 | 57 | 29 | 86 / 88 | 2 of 11 | 1.34 (0.59–3.02) |
| 16 | 93 | 67 | 160 / 176 | 5 of 11 | 1.52 (0.72–2.89) |
| 32 | 179 | 101 | 280 / 352 | 8 of 11 | 1.76 (0.98–3.89) |
| Versions | Main changes | Failures that motivated them | Completed |
|---|---|---|---|
| up to v8 | First full chain; localization from the bar and the basket; crossing window and stance planner; grasp retries; basket approach by turning, then walking | Odometry off by 0.55 m; a walk onto the bar; a fall from 25.6 cm; a false miss that dropped the hammer | 4/13 |
| v9–v9g | Left step aimed by the stance model; handle at 60 ∘ ; deadlines; a subagent’s grasp measured at 3/13 against 13/22 and reverted | Late grasps; sweeps of the desk | 5/10 |
| v9h–v9k | Looser carrying posture; limited fine steps and backing off; window back to 21.5 cm | The arm over the head; the hammer lost; a fall from 22.4 cm | 3/7 |
| v9l–v9o | Limits on the trailing sole; stance model refitted on 60 transitions with a calibration episode; correction of the handle axis | A fall with the trailing sole 41.8 cm back; a handle at 85 ∘ ; a flipped hammer | 8/12 |
| v9p–v9t | Trailing-sole margin from the 27/27 against 4/13 record; search turn; stall guard; placing in a partly seen basket | A fall in rehearsal; stalled steps; a basket not seen | 6/13 |
| v9u–v9u5b | Re-approach; correction of lateral drift (9.5 cm, ); cycle guard; a faster place near the step limit | Three to six actions at the bar; a rehearsal cut off with 49 steps left | 9/18 |
| Task | Instruction | Episodes | Before after |
|---|---|---|---|
| Long 3 | put the black bowl in the bottom drawer of the cabinet and close it | 5 | 0 100 |
| Long 8 | put both moka pots on the stove | 5 | 0 100 |
| Long 9 | put the yellow and white mug in the microwave and close it | 4 | 0 2 |
| Goal 1 | put the bowl on the stove | 5 | 2 96 |
| Goal 5 | push the plate to the front of the stove | 4 | 2 44 |
| ASPIRE | RAX | |
|---|---|---|
| Programs per task | one per perturbation | one, adapted on 5 of 40 tasks |
| Instances from the evaluation distribution | 30 | 0, or up to 5 when adapted |
| Rollouts on these instances | up to 75, plus evolutionary search | 0, or up to 5 when adapted |
| Exploration on unperturbed layouts | – | up to 20 episodes |
| Evaluation under perturbation | after development on it | zero-shot, or after adaptation |
| Part of the model | In each scene | Source |
|---|---|---|
| Position and orientation (axis , pull direction ) | estimated | lid circle and handle direction in the point cloud |
| Handle face, arm height, lateral offset | estimated | handle points in the point cloud |
| Drawer opening (joint state) | measured | shift of the handle face after the pull |
| Radii, heights, handle dimensions | fixed | the agent’s measurements from its first manual run |
Robot Learning
Robot learning develops methods for robots to acquire skills and adapt from demonstrations, interaction, data, and physical models.
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