ModalAI Forum
    • Categories
    • Recent
    • Tags
    • Popular
    • Users
    • Groups
    • Register
    • Login

    Garbage attitude control

    Ask your questions right here!
    9
    27
    2216
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as topic
    Log in to reply
    This topic has been deleted. Only users with topic management privileges can see it.
    • Chad SweetC
      Chad Sweet ModalAI Team
      last edited by

      Which ESCs are you using? The ModalAI ESC is closed loop RPM control for efficiency and requires its own calibration to the motors and propellers

      https://docs.modalai.com/modal-esc-v2-manual/#calibration
      https://gitlab.com/voxl-public/flight-core-px4/voxl-esc/-/blob/master/tools/calibration.md

      1 Reply Last reply Reply Quote 0
      • Patrick HincheyP
        Patrick Hinchey
        last edited by

        Thanks for the quick reply, Chad!
        We're using a standard 4-in-1 racing ESC on PWM. We have a 6S battery so we couldn't use the ModalAI ESC but I've just ordered some of your new T-motor F55As.

        1 Reply Last reply Reply Quote 0
        • Chad SweetC
          Chad Sweet ModalAI Team
          last edited by

          Then it sounds like you're using the M0065 VOXL 2 I/O board with it to generate PWM? If so, have you tried calibrating those ESC? https://docs.modalai.com/voxl2-io-user-guide/#pwm-esc-calibration

          Otherwise, it still sounds like platform tuning... Can you copy the working parameters from your Pixhawk over?

          Patrick HincheyP 1 Reply Last reply Reply Quote 0
          • Patrick HincheyP
            Patrick Hinchey @Chad Sweet
            last edited by

            @Chad-Sweet yep, we're using the I/O expander. We calibrated the ESC and and tried with the pixhawk's gains too, and it was still unflyable. Again, I have plenty of experience tuning PIDs, and nothing I could do could make this stable. Would it help if I uploaded some logs?

            1 Reply Last reply Reply Quote 0
            • Chad SweetC
              Chad Sweet ModalAI Team
              last edited by

              Yes, of course. logs.px4.io is a good way

              1 Reply Last reply Reply Quote 0
              • Chad SweetC
                Chad Sweet ModalAI Team
                last edited by

                Another thought... Did you configure the mixer using these docs: https://docs.modalai.com/voxl2-io-user-guide/#supported-mixers-and-airframe-setup

                And then did you disable the modal_esc driver?

                Tamas Pal 0T 1 Reply Last reply Reply Quote 0
                • Tamas Pal 0T
                  Tamas Pal 0 @Chad Sweet
                  last edited by

                  @Chad-Sweet I am also having same issue. Can you please tell what is modal_esc driver? How to disable it ?

                  Patrick HincheyP 1 Reply Last reply Reply Quote 0
                  • Patrick HincheyP
                    Patrick Hinchey @Tamas Pal 0
                    last edited by

                    Hmm, that's really interesting. Looking back at the parameters from those tests, the UART_ESC_CONFIG was set to 1. I'll set it to 0 and see what happens.
                    @Tamas-Pal-0 go into qgroudcontrol parameters and set UART_ESC_CONFIG to 0. please post your results!

                    1 Reply Last reply Reply Quote 0
                    • modaltbM
                      modaltb ModalAI Team
                      last edited by

                      Guys, I'm actively looking at this and will report what I find, it's my top priority.

                      1 Reply Last reply Reply Quote 0
                      • Patrick HincheyP
                        Patrick Hinchey
                        last edited by

                        Thank you @modaltb , much appreciated. I look forward to your findings. I disabled the modal_esc driver and it didn't help. Here is a log of the VOXL as flight controller, and one with a Pixhawk 4 as flight controller, with identical parameters. Both were mounted to the aircraft the whole time, all we did was swap wires around between flights.
                        Obviously there's still room for improvement with the Pixhawk 4 but for the most part it flew really well with default PID gains, whereas we couldn't even get the VOXL2 stable.

                        VOXL2:
                        https://logs.px4.io/plot_app?log=25afc87c-37cd-4693-9318-df62be99e4bd

                        Pixhawk 4:
                        https://logs.px4.io/plot_app?log=4b8a4762-8f59-49ca-a7fc-af41d38c466b

                        Tamas Pal 0T 1 Reply Last reply Reply Quote 0
                        • Tamas Pal 0T
                          Tamas Pal 0 @Patrick Hinchey
                          last edited by

                          @Patrick-Hinchey I also have same experience like you. After disabling modalai_esc driver. I set UART_ESC_CONFIG to 0 also. It didn't help.

                          1 Reply Last reply Reply Quote 0
                          • modaltbM
                            modaltb ModalAI Team
                            last edited by modaltb

                            @Patrick-Hinchey ,

                            I'm still actively looking into this! One area that caught my eye is here:

                            https://github.com/modalai/px4-firmware/blob/voxl-dev/boards/modalai/rb5-flight/voxl-px4.config#L187

                            Out testing has been on a Sentinel setup and am wondering if there's some settings not propagating correctly.

                            This file can be edited on target to adjust, I'm going through some testing now.

                            1 Reply Last reply Reply Quote 0
                            • M
                              m1baldwin
                              last edited by m1baldwin

                              I saw something similar with PX4 version 1.13.1; I don't have a VOXL2, but I had an issue where with VOXL 1 Flight Deck with PX4 1.13.1 did not work well for me on a standard airframe.

                              I downgraded to 1.11.3 sub-version 0.2.3 - I think this is a Modal AI sub-version? - and had better luck, maybe try an earlier version of px4

                              1 Reply Last reply Reply Quote 0
                              • modaltbM
                                modaltb ModalAI Team
                                last edited by

                                No smoking gun, but here's a commit I have going that uses params instead of hard coded values that we could give a try.

                                https://github.com/modalai/px4-firmware/commit/a0317b59e72eeb90126788e71093726dafe70708

                                File changed is here: https://github.com/modalai/px4-firmware/blob/pr-m0065-mr1/boards/modalai/rb5-flight/voxl-px4.config

                                On monday, I did fly the default Sentinel params with this VOXL2 IO board, it oscillated like crazy and we did a quick dirty tune and got it reasonable.

                                I'm going to request that we do a full tune on our Sentinel here to ensure we can get same perf as expected with this setup so we have a ground truth. Will report back when I have info.

                                1 Reply Last reply Reply Quote 0
                                • modaltbM
                                  modaltb ModalAI Team
                                  last edited by

                                  Also, any chance you could post a link to a video of a flight to help us understand the failure mode even more?

                                  1 Reply Last reply Reply Quote 0
                                  • Patrick HincheyP
                                    Patrick Hinchey
                                    last edited by

                                    Thank you for looking into this.
                                    Here is a video
                                    https://drive.google.com/file/d/1qPXFrxluE-MyOOpnfHQJ5eT4XOLYvGNu/view?usp=share_link
                                    I'll try with the new config file tonight. However the Pixhawk4 parameters are very similar - min=1075, maz=1950 so I would be surprised if that mad all that much difference.
                                    Also, regarding tuning the VOXL2, I'm curious to hear your opinion on why the same gains on the same machine would work great on the Pixhawk4 but not on the VOXL2. The Pixhawk4 is running the latest stable release

                                    1 Reply Last reply Reply Quote 0
                                    • modaltbM
                                      modaltb ModalAI Team
                                      last edited by

                                      Hey @Patrick-Hinchey ,

                                      Thanks for the video, I'm gonna get some teammates to help early this week who are much more versed in this area.

                                      Here's my setup, it's VOXL2 with VOXL2 IO, as you can see it's flyable but a little rough, I too initially had a wobble that prevented me from flying and changed params a bit from our default Sentinel settings to get it airborne:
                                      https://www.youtube.com/watch?v=1INto92k-v0

                                      I'll get some members of the team early this week to better answer your second question and we'll keep cranking away.

                                      1 Reply Last reply Reply Quote 0
                                      • Daniel MellingerD
                                        Daniel Mellinger ModalAI Team
                                        last edited by

                                        Hi @Patrick-Hinchey, we are actively working on figuring out the answer your question about "why the same gains on the same machine would work great on the Pixhawk4 but not on the VOXL2." There are several differences between the PX4 code running on VOXL2 compared to Pixhawk4. Specifically, the path of the PWM commands to the motors including the px4io setup is different on VOXL2 compared to Pixhawk4. Additionally, VOXL2 uses a different IMU than Pixhawk4 and that IMU is configured differently. We will keep you posted on what we are able to figure out.

                                        1 Reply Last reply Reply Quote 0
                                        • ?
                                          A Former User
                                          last edited by A Former User

                                          @Patrick-Hinchey

                                          I hope all is well!

                                          I'm sorry you're dealing with this - I know it can be frustrating.

                                          I'm jumping here a little late and may have missed something. I was wondering, can you confirm that you have the correct motor mapping:
                                          f58f9527-186f-40ab-8c76-a389971eebc1-image.png

                                          Also, were you able to successfully run through a PWM ESC calibration using these Instructions? Which specific ESCs are you using? Did you hear the expected chimes (maybe firmware not accepting)?

                                          1 Reply Last reply Reply Quote 0
                                          • Patrick HincheyP
                                            Patrick Hinchey
                                            last edited by

                                            Thank you for your insight everyone,

                                            We have an important milestone coming up in 2 weeks so we're going to use the external flight controller until then and then resume troubleshooting this issue after that - trying all the suggestions above.

                                            Thanks, see you in 2 weeks!

                                            1 Reply Last reply Reply Quote 0
                                            • First post
                                              Last post
                                            Powered by NodeBB | Contributors