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nutonomy / nuscenes-devkit

The devkit of the nuScenes dataset.
https://www.nuScenes.org
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Which one is the IMU data? ego_pose.json/V1.0-trainval, scene-xxxx_ms_imu.json/can_bus, or scene-xxxx_pose.json/can_bus? #1111

Closed Rango-T10000 closed 1 month ago

Rango-T10000 commented 2 months ago

Dear authors:

Thanks for your valuable dataset. I have a question about IMU data. In this dataset, I find the quaternion(w, x, y, z ) is used to express the 3D rotation of ego car in this dataset. However, I find that the quaternion(w, x, y, z ) shows in the following different files:

  1. ego_pose.json/V1.0-trainval:

    image

  2. scene-xxxx_ms_imu.json/can_bus:

    image

  3. scene-xxxx_pose.json/can_bus:

    image

I am confused about all these quaternion(w, x, y, z ), so which one is the real IMU data for the ego car? Could you please help me with that?

whyekit-motional commented 2 months ago

The quaternions in *_imu.json are from the raw IMU data, while those in ego_pose.json and scene_*_pose.json are the outputs of a lidar map-based localization algorithm