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  4. VIO errors with new AR0144 tracking camera unstable flight/crashing

VIO errors with new AR0144 tracking camera unstable flight/crashing

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  • Gary HolmgrenG Offline
    Gary HolmgrenG Offline
    Gary Holmgren
    Regular
    wrote on last edited by
    #1
    This post is deleted!
    Alex KushleyevA 1 Reply Last reply
    0
    • Gary HolmgrenG Gary Holmgren

      This post is deleted!

      Alex KushleyevA Offline
      Alex KushleyevA Offline
      Alex Kushleyev
      ModalAI Team
      wrote on last edited by Alex Kushleyev
      #2

      @Gary-Holmgren ,

      Here are a few suggestions to help debug this:

      • I noticed that you have a 180 degree rotation specified for the camera config. This rotation is achieved by reversing the readout order from the camera, which affects the intrinsic calibration. Make sure you calibrate your camera's intrinsics with the same rotation (enabled or disabled) as you are testing, otherwise the intrinsics will not be valid.
      • whenever working on a new setup, always test VIO in hand-held tests in order to eliminate other variables. If VIO does not work in hand-held tests, there is no hope that it will work in flight
      • do you ever have cases where VIO works for some time, maybe 5-10 seconds while you are moving (and then blows up) or is it always blowing up as soon as you start moving? If the latter is the case, majority of the cases is incorrect extrinsic parameters (specifically, camera to IMU rotation). did you calculate your extrinsics based on rotated or not rotated camera configuration?
      • please share the results of your intrinsic calibration, just to double check it
      • double check camera focus, anything farther than 6 inches or so should be in clear focus (fisheye lenses have very short focal distance and large depth of field)

      Alex

      Gary HolmgrenG 2 Replies Last reply
      1
      • Alex KushleyevA Alex Kushleyev referenced this topic on
      • Alex KushleyevA Alex Kushleyev

        @Gary-Holmgren ,

        Here are a few suggestions to help debug this:

        • I noticed that you have a 180 degree rotation specified for the camera config. This rotation is achieved by reversing the readout order from the camera, which affects the intrinsic calibration. Make sure you calibrate your camera's intrinsics with the same rotation (enabled or disabled) as you are testing, otherwise the intrinsics will not be valid.
        • whenever working on a new setup, always test VIO in hand-held tests in order to eliminate other variables. If VIO does not work in hand-held tests, there is no hope that it will work in flight
        • do you ever have cases where VIO works for some time, maybe 5-10 seconds while you are moving (and then blows up) or is it always blowing up as soon as you start moving? If the latter is the case, majority of the cases is incorrect extrinsic parameters (specifically, camera to IMU rotation). did you calculate your extrinsics based on rotated or not rotated camera configuration?
        • please share the results of your intrinsic calibration, just to double check it
        • double check camera focus, anything farther than 6 inches or so should be in clear focus (fisheye lenses have very short focal distance and large depth of field)

        Alex

        Gary HolmgrenG Offline
        Gary HolmgrenG Offline
        Gary Holmgren
        Regular
        wrote on last edited by
        #3
        This post is deleted!
        1 Reply Last reply
        0
        • Alex KushleyevA Alex Kushleyev

          @Gary-Holmgren ,

          Here are a few suggestions to help debug this:

          • I noticed that you have a 180 degree rotation specified for the camera config. This rotation is achieved by reversing the readout order from the camera, which affects the intrinsic calibration. Make sure you calibrate your camera's intrinsics with the same rotation (enabled or disabled) as you are testing, otherwise the intrinsics will not be valid.
          • whenever working on a new setup, always test VIO in hand-held tests in order to eliminate other variables. If VIO does not work in hand-held tests, there is no hope that it will work in flight
          • do you ever have cases where VIO works for some time, maybe 5-10 seconds while you are moving (and then blows up) or is it always blowing up as soon as you start moving? If the latter is the case, majority of the cases is incorrect extrinsic parameters (specifically, camera to IMU rotation). did you calculate your extrinsics based on rotated or not rotated camera configuration?
          • please share the results of your intrinsic calibration, just to double check it
          • double check camera focus, anything farther than 6 inches or so should be in clear focus (fisheye lenses have very short focal distance and large depth of field)

          Alex

          Gary HolmgrenG Offline
          Gary HolmgrenG Offline
          Gary Holmgren
          Regular
          wrote on last edited by Gary Holmgren
          #4
          This post is deleted!
          Alex KushleyevA 1 Reply Last reply
          0
          • Gary HolmgrenG Gary Holmgren

            This post is deleted!

            Alex KushleyevA Offline
            Alex KushleyevA Offline
            Alex Kushleyev
            ModalAI Team
            wrote on last edited by Alex Kushleyev
            #5

            @Gary-Holmgren , I think your imu -> tracking camera rotation should be:

            "RPY_parent_to_child": [0, 45, 90] (+90, not -90). Even though your flex is pointing up, you have specified in camera server config to rotate the image (in the camera ISP itself).

            Try that..

            What i meant about the calibration / rotation.. make sure that you set the "en_rotate": true in voxl-camera-server.conf and then perform the camera calibration, so that you calibrate the camera with the correct internal (to camera) image rotation. If you perform intrinsics calibration and then change the internal camera rotation, the calibration will not be correct (principal points will be flipped, at least).

            I checked, the video, it basically shows ZERO feature tracking, so the transform issue is probably causing this.

            Alex

            Gary HolmgrenG 2 Replies Last reply
            1
            • Alex KushleyevA Alex Kushleyev

              @Gary-Holmgren , I think your imu -> tracking camera rotation should be:

              "RPY_parent_to_child": [0, 45, 90] (+90, not -90). Even though your flex is pointing up, you have specified in camera server config to rotate the image (in the camera ISP itself).

              Try that..

              What i meant about the calibration / rotation.. make sure that you set the "en_rotate": true in voxl-camera-server.conf and then perform the camera calibration, so that you calibrate the camera with the correct internal (to camera) image rotation. If you perform intrinsics calibration and then change the internal camera rotation, the calibration will not be correct (principal points will be flipped, at least).

              I checked, the video, it basically shows ZERO feature tracking, so the transform issue is probably causing this.

              Alex

              Gary HolmgrenG Offline
              Gary HolmgrenG Offline
              Gary Holmgren
              Regular
              wrote on last edited by
              #6
              This post is deleted!
              1 Reply Last reply
              0
              • Alex KushleyevA Alex Kushleyev

                @Gary-Holmgren , I think your imu -> tracking camera rotation should be:

                "RPY_parent_to_child": [0, 45, 90] (+90, not -90). Even though your flex is pointing up, you have specified in camera server config to rotate the image (in the camera ISP itself).

                Try that..

                What i meant about the calibration / rotation.. make sure that you set the "en_rotate": true in voxl-camera-server.conf and then perform the camera calibration, so that you calibrate the camera with the correct internal (to camera) image rotation. If you perform intrinsics calibration and then change the internal camera rotation, the calibration will not be correct (principal points will be flipped, at least).

                I checked, the video, it basically shows ZERO feature tracking, so the transform issue is probably causing this.

                Alex

                Gary HolmgrenG Offline
                Gary HolmgrenG Offline
                Gary Holmgren
                Regular
                wrote on last edited by Gary Holmgren
                #7
                This post is deleted!
                Alex KushleyevA 1 Reply Last reply
                0
                • Gary HolmgrenG Gary Holmgren

                  This post is deleted!

                  Alex KushleyevA Offline
                  Alex KushleyevA Offline
                  Alex Kushleyev
                  ModalAI Team
                  wrote on last edited by
                  #8

                  @Gary-Holmgren , great! The transforms can be tricky sometimes especially with the added complexity of the image rotation in the camera…

                  Alex

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