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  3. FC v2 Collision prevention issue with voxl 2

FC v2 Collision prevention issue with voxl 2

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  • S Sean Hickey

    @Jetson-Nano

    Looking through the PX4 codebase, the ARK Flow MR publishes to distance_sensor by default, not obstacle_distance. Have you made any changes to the codebase that would affect obstacle_distance or mounted any other sensors?

    Also, how have you mounted the ark_flow_mr. Is it pointing downwards on the vehicle, or forward pointing or some other configuration?

    Finally, have you tried setting the distance for collision prevention higher, and seeing how the drone reacts in that case?

    Jetson NanoJ Offline
    Jetson NanoJ Offline
    Jetson Nano
    Veteran
    wrote last edited by
    #6

    @Sean-Hickey I am using the optical flow sensor for position hold, it is attached directly to the FC.

    I am getting the obstacle_distance messages from the TOF sensor and I am able to see it.
    I did check with 1 m cp_dist and it was not working.

    S 1 Reply Last reply
    0
    • Jetson NanoJ Jetson Nano

      @Sean-Hickey I am using the optical flow sensor for position hold, it is attached directly to the FC.

      I am getting the obstacle_distance messages from the TOF sensor and I am able to see it.
      I did check with 1 m cp_dist and it was not working.

      S Offline
      S Offline
      Sean Hickey
      wrote last edited by
      #7

      @Jetson-Nano

      What TOF sensor are you using for obstacle distance?

      Just confirming, you are using the ARK Flow MR facing downwards just for optical flow and position hold, but not for collision prevention?

      Jetson NanoJ 1 Reply Last reply
      0
      • S Sean Hickey

        @Jetson-Nano

        What TOF sensor are you using for obstacle distance?

        Just confirming, you are using the ARK Flow MR facing downwards just for optical flow and position hold, but not for collision prevention?

        Jetson NanoJ Offline
        Jetson NanoJ Offline
        Jetson Nano
        Veteran
        wrote last edited by
        #8

        @Sean-Hickey PMD tof that comes with yellow board M0173 - https://docs.modalai.com/M0173/

        Yes optical flow is facing down, it is used for position hold and not for collision prevention.

        S 1 Reply Last reply
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        • Jetson NanoJ Jetson Nano

          @Sean-Hickey PMD tof that comes with yellow board M0173 - https://docs.modalai.com/M0173/

          Yes optical flow is facing down, it is used for position hold and not for collision prevention.

          S Offline
          S Offline
          Sean Hickey
          wrote last edited by
          #9

          @Jetson-Nano

          Can you see if you are using the MO169 or the MO178?

          Jetson NanoJ 1 Reply Last reply
          0
          • S Sean Hickey

            @Jetson-Nano

            Can you see if you are using the MO169 or the MO178?

            Jetson NanoJ Offline
            Jetson NanoJ Offline
            Jetson Nano
            Veteran
            wrote last edited by
            #10

            @Sean-Hickey I am using M0178

            S 1 Reply Last reply
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            • Jetson NanoJ Jetson Nano

              @Sean-Hickey I am using M0178

              S Offline
              S Offline
              Sean Hickey
              wrote last edited by Sean Hickey
              #11

              @Jetson-Nano

              I was able to identify the issue.

              mpc_pos_mode - acceleration based doesn't call Collision Prevention in any of the newest PX4 builds..

              You need to use mpc_pos_mode - Simple Position Control (0) or mpc_pos_mode - smooth position control (3).

              I was able to test this on a similar setup, and confirmed that collision prevention only worked with the mpc_pos_mode indicated above, and notably did not with mpc_pos_mode acceleration.

              Jetson NanoJ 1 Reply Last reply
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              • S Sean Hickey

                @Jetson-Nano

                I was able to identify the issue.

                mpc_pos_mode - acceleration based doesn't call Collision Prevention in any of the newest PX4 builds..

                You need to use mpc_pos_mode - Simple Position Control (0) or mpc_pos_mode - smooth position control (3).

                I was able to test this on a similar setup, and confirmed that collision prevention only worked with the mpc_pos_mode indicated above, and notably did not with mpc_pos_mode acceleration.

                Jetson NanoJ Offline
                Jetson NanoJ Offline
                Jetson Nano
                Veteran
                wrote last edited by
                #12

                @Sean-Hickey that great, just making sure, did you use optical flow with FC?

                Also could you let me know which branch you used, or the Px4 built file. i want to test it out in my setup.

                S 1 Reply Last reply
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                • Jetson NanoJ Jetson Nano

                  @Sean-Hickey that great, just making sure, did you use optical flow with FC?

                  Also could you let me know which branch you used, or the Px4 built file. i want to test it out in my setup.

                  S Offline
                  S Offline
                  Sean Hickey
                  wrote last edited by
                  #13

                  @Jetson-Nano

                  I used VIO with FC, but the path from obstacle detection to Collision Prevention is unchanged between the 2 modes.

                  I used the mainline ModalAI PX4 SDK branch. I can share the built px4 deb build with you if that's helpful, but I would try changing the mpc_pos_mode parameter first on your current build to see if that fixes your issue.

                  Jetson NanoJ 1 Reply Last reply
                  0
                  • S Sean Hickey

                    @Jetson-Nano

                    I used VIO with FC, but the path from obstacle detection to Collision Prevention is unchanged between the 2 modes.

                    I used the mainline ModalAI PX4 SDK branch. I can share the built px4 deb build with you if that's helpful, but I would try changing the mpc_pos_mode parameter first on your current build to see if that fixes your issue.

                    Jetson NanoJ Offline
                    Jetson NanoJ Offline
                    Jetson Nano
                    Veteran
                    wrote last edited by
                    #14

                    @Sean-Hickey
                    I already checked with changing the MPC_POS_MODE, did not work.

                    Could you share the file, I would like to test it out.

                    S 2 Replies Last reply
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                    • Jetson NanoJ Jetson Nano

                      @Sean-Hickey
                      I already checked with changing the MPC_POS_MODE, did not work.

                      Could you share the file, I would like to test it out.

                      S Offline
                      S Offline
                      Sean Hickey
                      wrote last edited by
                      #15

                      @Jetson-Nano

                      voxl-px4_1.14.0-2.0.142_arm64.deb

                      favicon

                      Google Docs (drive.google.com)

                      I attached the link above, I am using parameters:

                      MPC_POS_MODE: Simple position control
                      CP_DIST 1.5 m
                      CP_DELAY 0.4 s
                      CP_GUIDE_ANG : 0 deg
                      CP_GO_NO_DATA: Enabled

                      1 Reply Last reply
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                      • Jetson NanoJ Jetson Nano

                        @Sean-Hickey
                        I already checked with changing the MPC_POS_MODE, did not work.

                        Could you share the file, I would like to test it out.

                        S Offline
                        S Offline
                        Sean Hickey
                        wrote last edited by Sean Hickey
                        #16

                        @Jetson-Nano

                        If this doesn't work, on the mavlink console (after testing the collision prevention) call:
                        listener obstacle_distance_fused 1
                        listener collision_constraints 1

                        and let me know the results.

                        Jetson NanoJ 2 Replies Last reply
                        0
                        • S Sean Hickey

                          @Jetson-Nano

                          If this doesn't work, on the mavlink console (after testing the collision prevention) call:
                          listener obstacle_distance_fused 1
                          listener collision_constraints 1

                          and let me know the results.

                          Jetson NanoJ Offline
                          Jetson NanoJ Offline
                          Jetson Nano
                          Veteran
                          wrote last edited by Jetson Nano
                          #17

                          @Sean-Hickey
                          sorry to disturb you again .
                          I am not able to flash with the deb file, could you please share the .px4 file

                          1 Reply Last reply
                          0
                          • S Sean Hickey

                            @Jetson-Nano

                            If this doesn't work, on the mavlink console (after testing the collision prevention) call:
                            listener obstacle_distance_fused 1
                            listener collision_constraints 1

                            and let me know the results.

                            Jetson NanoJ Offline
                            Jetson NanoJ Offline
                            Jetson Nano
                            Veteran
                            wrote last edited by
                            #18

                            @Sean-Hickey

                            I tested with this firmware modalai_fc-v2_1.14.0-2.0.133.px4 from (http://voxl-packages.modalai.com/dists/fc-v2/sdk-1.6/ ) and it worked, but there is no uavcan thats the only problem.

                            I checked with the parameters you mentioned.

                            When i reduce the cp_dist it stops working but with 1.5 m it is working.

                            Eric KatzfeyE 1 Reply Last reply
                            1
                            • Jetson NanoJ Jetson Nano

                              @Sean-Hickey

                              I tested with this firmware modalai_fc-v2_1.14.0-2.0.133.px4 from (http://voxl-packages.modalai.com/dists/fc-v2/sdk-1.6/ ) and it worked, but there is no uavcan thats the only problem.

                              I checked with the parameters you mentioned.

                              When i reduce the cp_dist it stops working but with 1.5 m it is working.

                              Eric KatzfeyE Offline
                              Eric KatzfeyE Offline
                              Eric Katzfey
                              ModalAI Team
                              wrote last edited by
                              #19

                              @Jetson-Nano Can you rebuild to add UAVCAN? The code is here: https://github.com/modalai/px4-firmware/tree/v1.14.0-2.0.133-dev

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