moonbeards/sim_stack_v2

About this dataset (SO-101 cube stacking project, sim-to-real, 2026-10)

296 simulated episodes (150,130 frames, 30 Hz) generated automatically in a MuJoCo model of the SO-101 whose dynamics (command delay 3 frames, per-joint gains), cube contact, cameras (top intrinsics/homography, wrist hand-eye) and appearance were fitted to the real robot by measurement. An inverse-kinematics planner produced the demonstrations following the statistics of real human demonstrations (approach direction, speed, episode length ≈ 16 s); placements are half real-distribution, half full reach; lighting, colour, size and camera pose are randomized. Stiff cube contact and pan/roll gains 16 (the "v2" conditions). Single task: "Pick up the orange cube and place it on top of the red cube". No human demonstration was used.

Policy trained on it: moonbeards/smolvla_sim_stack_v2 (checkpoint 10k → real SO-101 2/10 without any real data). Full project, simulator code and analysis: GitHub repository https://github.com/GGOMOONG/so101-cube-stacking. Author: moonbeards.

This dataset was created using LeRobot.

Dataset Structure

meta/info.json:

{
    "codebase_version": "v3.0",
    "fps": 30,
    "features": {
        "action": {
            "dtype": "float32",
            "shape": [
                6
            ],
            "names": [
                "shoulder_pan.pos",
                "shoulder_lift.pos",
                "elbow_flex.pos",
                "wrist_flex.pos",
                "wrist_roll.pos",
                "gripper.pos"
            ]
        },
        "observation.state": {
            "dtype": "float32",
            "shape": [
                6
            ],
            "names": [
                "shoulder_pan.pos",
                "shoulder_lift.pos",
                "elbow_flex.pos",
                "wrist_flex.pos",
                "wrist_roll.pos",
                "gripper.pos"
            ]
        },
        "observation.images.top": {
            "dtype": "video",
            "shape": [
                480,
                640,
                3
            ],
            "names": [
                "height",
                "width",
                "channels"
            ],
            "info": {
                "video.height": 480,
                "video.width": 640,
                "video.codec": "h264",
                "video.pix_fmt": "yuv420p",
                "video.fps": 30,
                "video.channels": 3,
                "has_audio": false,
                "video.g": 2,
                "video.crf": 30,
                "video.preset": null,
                "video.fast_decode": 0,
                "video.video_backend": "pyav",
                "video.extra_options": {},
                "is_depth_map": false
            }
        },
        "observation.images.wrist": {
            "dtype": "video",
            "shape": [
                480,
                640,
                3
            ],
            "names": [
                "height",
                "width",
                "channels"
            ],
            "info": {
                "video.height": 480,
                "video.width": 640,
                "video.codec": "h264",
                "video.pix_fmt": "yuv420p",
                "video.fps": 30,
                "video.channels": 3,
                "has_audio": false,
                "video.g": 2,
                "video.crf": 30,
                "video.preset": null,
                "video.fast_decode": 0,
                "video.video_backend": "pyav",
                "video.extra_options": {},
                "is_depth_map": false
            }
        },
        "timestamp": {
            "dtype": "float32",
            "shape": [
                1
            ],
            "names": null
        },
        "frame_index": {
            "dtype": "int64",
            "shape": [
                1
            ],
            "names": null
        },
        "episode_index": {
            "dtype": "int64",
            "shape": [
                1
            ],
            "names": null
        },
        "index": {
            "dtype": "int64",
            "shape": [
                1
            ],
            "names": null
        },
        "task_index": {
            "dtype": "int64",
            "shape": [
                1
            ],
            "names": null
        }
    },
    "total_episodes": 296,
    "total_frames": 150130,
    "total_tasks": 1,
    "chunks_size": 1000,
    "data_files_size_in_mb": 100,
    "video_files_size_in_mb": 200,
    "data_path": "data/chunk-{chunk_index:03d}/file-{file_index:03d}.parquet",
    "video_path": "videos/{video_key}/chunk-{chunk_index:03d}/file-{file_index:03d}.mp4",
    "robot_type": "so_follower",
    "splits": {
        "train": "0:296"
    }
}

Citation

BibTeX:

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