SN0429/so101_pick_cube_test_20260823_40ep_fixed

This dataset was created using LeRobot.

What this is

The robot-faithful repair of SN0429/so101_pick_cube_test_20260823_40ep. Angles are exactly what the follower reported, with only the encoder wrap removed.

Use this one for ACT training and lerobot-replay. Its degree zero is LeRobot's own convention - the pose held during calibration - which is what the real arm expects.

For 3D visualisation or Isaac Sim, use ..._40ep_urdf instead: LeRobot's zero is about 97 degrees away from the SO-101 URDF's zero on elbow_flex, and the sign is flipped, so rendering this copy against the URDF puts the arm in the wrong posture.

Joint	Correction	Result
elbow_flex	unwrapped per episode, no offset	largest within-episode step 360 deg -> 6 deg
the other five	untouched	byte-identical to the original

The original recording had two joints sitting on the STS3215 encoder's 0/4095 wrap point, because the pose held during calibration was not the middle of their real travel. elbow_flex crossed it, so the reading rolled 4095 -> 0 and the recorded angle jumped a full 360 degrees; wrist_roll stopped 43 counts short of it and could not be commanded past it, leaving a ~16 degree gap between commanded and measured position.

Unwrapping elbow_flex is common to both copies and is exact: a wrap is an artefact of the angle representation, so making each episode continuous restores the trajectory (largest within-episode step drops from 360 to 6 degrees).

wrist_roll is not recoverable in either copy. Where it was commanded past the boundary the arm never went there, so no measurement of the intended pose exists. Do not train a policy on that joint - those episodes need re-recording after recalibrating both arms.

Repaired with so101-unwrap-dataset; see SO101_ENCODER_WRAP.md in the LeRobot fork used here.

Dataset Structure

meta/info.json:

{
    "codebase_version": "v3.0",
    "fps": 30,
    "features": {
        "action": {
            "dtype": "float32",
            "names": [
                "shoulder_pan.pos",
                "shoulder_lift.pos",
                "elbow_flex.pos",
                "wrist_flex.pos",
                "wrist_roll.pos",
                "gripper.pos"
            ],
            "shape": [
                6
            ]
        },
        "observation.state": {
            "dtype": "float32",
            "names": [
                "shoulder_pan.pos",
                "shoulder_lift.pos",
                "elbow_flex.pos",
                "wrist_flex.pos",
                "wrist_roll.pos",
                "gripper.pos"
            ],
            "shape": [
                6
            ]
        },
        "observation.images.front": {
            "dtype": "video",
            "shape": [
                480,
                640,
                3
            ],
            "names": [
                "height",
                "width",
                "channels"
            ],
            "info": {
                "is_depth_map": false,
                "video.height": 480,
                "video.width": 640,
                "video.codec": "av1",
                "video.pix_fmt": "yuv420p",
                "video.fps": 30,
                "video.channels": 3,
                "has_audio": false,
                "video.g": 2,
                "video.crf": 30,
                "video.preset": 12,
                "video.fast_decode": 0,
                "video.video_backend": "pyav",
                "video.extra_options": {}
            }
        },
        "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": 40,
    "total_frames": 35676,
    "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": "0:40"
    }
}

Citation

BibTeX:

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