AI

XR-2 Trains on 1,500 Hours of Two-Handed Housework, Then DAgger

Shar Hendrix 4 min read

Bimanual household work is still starved for data that looks like a Tuesday laundry pile. A PrimeBot / Peking University / Crobotia team posted a dump on 3 September: 1,500 hours of two-handed demos, a 5B-parameter VLA they call XR-2, and a scaling plot that actually bends.

The robot is the X2W: two 7-DoF arms with 1-DoF grippers, a 4-DoF waist, a 2-DoF head, and a three-wheel omni base β€” 25 control variables, states logged at 30 Hz. Cameras: a RealSense D435i, ZED X Mini, and two ZED-XONE GS wrists, plus dual Jetson AGX Orin compute in the diagram.

X2W wheeled bimanual robot with labeled cameras, arms, torso, and compute
X2W hardware callouts. Source: Xu et al., arXiv:2609.03591.

Two pipelines, one pile of clothes

The real-robot slice is 32,518 teleop trajectories, 57.4 million frames, 531.7 hours, frame-level language. Four scenes: folding station (~14.6k traj), washer (~8.4k), sofa (~6.1k), laundry basket (~3.4k). Some episodes run past 150 s. After merging equivalent instructions they list 11 atomic skills; fold-clothes alone is 14.6k.

The UMI slice is about 1,000 hours of handheld-gripper folding, from more than 200 households and 100 collectors, covering 5,000 garments. Dual 960Γ—960 video at 30 Hz, metric 6-DoF trajectories from visual-inertial SLAM, gripper aperture from vision, no encoders on the jaws. Sessions can run 90 minutes without a reset.

XR-2 is a Mixture-of-Transformer: Qwen3-VL-4B-Instruct plus an 18-block flow-matching action expert (hidden 1024, 8 heads). Deployment: RTX 4090, async inference at 10 Hz, action chunk 50Γ—25, commands issued at 30 Hz after a 1000 Hz whole-body controller.

Head-camera strips of washer loading, basket handling, and clothes folding
Real-robot episodes from the head camera. Source: Xu et al., arXiv:2609.03591.

Expert data saturates. Corrections do not.

On clothes folding, success climbs from 34% at 30 hours of expert data to 84% at 120 hours, then 82% at 160 hours. Extra expert hours stop helping.

DAgger starts from a checkpoint trained on 18,695 expert trajectories across 10 sub-tasks (58% on folding). Three rounds, 2.5 epochs each, with extra correction budget on the weak sub-tasks: 74%, 82%, 93%. That is a 35-point lift over the expert-only start.

Egocentric UMI gripper sequences folding shirts, a sweater, a jacket, and jeans in real homes
In-the-wild UMI folding across households. Source: Xu et al., arXiv:2609.03591.

The authors say a model at 85% under their slight generalization (size, color, start pose) clears 95% in-distribution. Data and a URDF live on Hugging Face. A change log in the paper says full data and an IROS 2026 household bimanual challenge launched in July 2026.

A Human’s Take

A thousand hours of people folding shirts in actual bedrooms is the part I would steal. The robot hours are the part I would trust for a washer door. Putting both under one VLA, then admitting expert data saturates at 120 hours on folding, is the adult version of β€œjust scale the demos.” If you are collecting, the next dollar is probably a human with a deadman switch, not another tidy teleop take.

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