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A question about VIO reference system.

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  • Caio Licínio Vasconcelos PantarottoC Offline
    Caio Licínio Vasconcelos PantarottoC Offline
    Caio Licínio Vasconcelos Pantarotto
    Contributor
    wrote on last edited by
    #1

    There is one thing on the VIO reference system that made me confused... We have T_imu_wrt_vio which is "Translation of the IMU with respect to VIO frame in meters", and we have T_cam_wrt_imu which is "Location of the optical center of the camera with respect to the IMU." I just want to clarify...

    1. I would think that T_cam_wrt_imu (Also the rotation) is a fixed number (since the vector between the camera and the imu should be constant in the fixed frame of the drone).. and when I measured it on the Starling indeed is something like (0.026 0.007 0.024) most of the time.. but the T and R (0 45 90) changes slightly during movement.. is this because the IMU itself moves internally a bit ?

    2. is the T_imu_wrt_vio the XYZ global position of the IMU that is given by the VIO algorithm ? So it should be interpreted as the position in space of the drone... Sorry the sentence "with respect to VIO frame" confused me a bit...

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    • Caio Licínio Vasconcelos PantarottoC Caio Licínio Vasconcelos Pantarotto

      There is one thing on the VIO reference system that made me confused... We have T_imu_wrt_vio which is "Translation of the IMU with respect to VIO frame in meters", and we have T_cam_wrt_imu which is "Location of the optical center of the camera with respect to the IMU." I just want to clarify...

      1. I would think that T_cam_wrt_imu (Also the rotation) is a fixed number (since the vector between the camera and the imu should be constant in the fixed frame of the drone).. and when I measured it on the Starling indeed is something like (0.026 0.007 0.024) most of the time.. but the T and R (0 45 90) changes slightly during movement.. is this because the IMU itself moves internally a bit ?

      2. is the T_imu_wrt_vio the XYZ global position of the IMU that is given by the VIO algorithm ? So it should be interpreted as the position in space of the drone... Sorry the sentence "with respect to VIO frame" confused me a bit...

      ModeratorM Offline
      ModeratorM Offline
      Moderator
      ModalAI Team
      wrote on last edited by
      #2

      @Caio-Licínio-Vasconcelos-Pantarotto the VIO algorithm takes the starting extrinsics and refines based on movement of the system. So, it's normal to see small updates to the value

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