RB5 Motor Cogging/Stuttering, Unable to upload firmware to new ESC
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Hi,
Our ModalAI RB5 has had an issue that make the motors cog/stutter - the motor halts spinning for a brief moment mid flight and then resumes spinning. We purchased and installed a new ESC (https://www.modalai.com/products/voxl-esc?variant=44746120298800) because we believed that the probable cause was an old ESC firmware and the ESC we had installed was too old making it incompatible with newer firmware versions.
Unfortunately, the cogging persists even with the new ESC. Attempts to upload the newer version firmware fails with the following error:
ERROR: An error occured during the write process.
See the entire command line output when we tried to upload the new firmware below:
rb5:/usr/share/modalai/voxl-esc-tools$ ./voxl-esc-upload-firmware.py --id 0 -f /usr/share/modalai/voxl-esc-tools/firmware/modalai_esc_fi
rmware_m0134_6_v0_39_RC11_17d64675.bin
Detected Python version : 3.6.9 (default, Mar 10 2023, 16:46:00)
[GCC 8.4.0]
dpkg-query: no packages found matching voxl-esc-board-detect.py
dpkg-query: no packages found matching voxl-esc-calibrate.py
dpkg-query: no packages found matching voxl-esc-led.py
dpkg-query: no packages found matching voxl-esc-neopixel-test.py
dpkg-query: no packages found matching voxl-esc-scan.py
dpkg-query: no packages found matching voxl-esc-spin-helper.sh
dpkg-query: no packages found matching voxl-esc-spin-sine.py
dpkg-query: no packages found matching voxl-esc-spin-step.py
dpkg-query: no packages found matching voxl-esc-spin.py
dpkg-query: no packages found matching voxl-esc-tools-bin
dpkg-query: no packages found matching voxl-esc-upload-firmware-all.sh
dpkg-query: no packages found matching voxl-esc-upload-firmware.py
dpkg-query: no packages found matching voxl-esc-upload-params.py
dpkg-query: no packages found matching voxl-esc-verify-params.py
dpkg-query: no packages found matching voxl_esc_setup_paths.py
dpkg-query: no packages found matching voxl_serial.py
Found voxl-esc tools bin version: 1.6INFO: Firmware file name : /usr/share/modalai/voxl-esc-tools/firmware/modalai_esc_firmware_m0134_6_v0_39_RC11_17d64675.bin
INFO: Firmware file size : 23104 bytesVOXL Platform: M0052
Detected RB5 Flight, VOXL2 M0054 or M0104!
INFO: Scanning for ESC firmware: /dev/slpi-uart-2, baud: 2000000
Sending library name request: libslpi_qrb5165_io.so
Received standard error event 2
Sending initialization request
INFO: ESC(s) detected on port: /dev/slpi-uart-2, baud rate: 2000000
INFO: ESC(s) detected: [0, 1, 2, 3]
INFO: Sending reset command to ESC ID 0
Updated baud rate to 230400
INFO: Installing firmware to ESC ID 0 : /usr/share/modalai/voxl-esc-tools/firmware/modalai_esc_firmware_m0134_6_v0_39_RC11_17d64675.bin
Progress: 3% [# ]
NACK ReceivedERROR: An error occured during the write process.
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Hello @senoa95 ,
The NACK reply from ESC means that you are trying to upload incompatible firmware (firmware for a different ESC board). You can check which board variant you have by running ./voxl-esc-scan.py , it will tell you, perahaps it is M0134-1 instead of M0134-6.
Also, there is an automatic script that detects the board type and uploads the latest firmware. Additionally, the firmware you are trying to upload is not the latest. Please get the latest scripts and firmware here : https://gitlab.com/voxl-public/voxl-sdk/utilities/voxl-esc (master or dev branch). The latest firmware for all ESC boards is 39.20. Just download the whole repository to your rb5 with latest voxl-esc tools. Depending on which SDK you have installed, you may be able to update it just by using
apt install voxl-escbut if your apt sources are set up to use the old sdk, you won't get the latestvoxl-escpackage, so it may be easier to just directly download it from gitlab.The script
voxl-esc-upload-firmware-all.shhas the ESC autodetect built-in and it will upload the latest firmware to all ESCs. Please try it.Regarding motor stuttering / cogging, it could be a mechanical issue with the motor, such as mounting screws penetrating into the motor windings, or something else like debris stuck between the motor stator and rotor and gets occasionally lodged and dislodged (since i don't know the nature of the cogging, this is just a guess).
If switching the ESC did not help, i would suggest carefully installing the latest firmware first. If the cogging still persists, please describe how often this happens (like once a minute or very rarely like once per 10 minutes of spinning). Does the cogging. happen on the same motor ever time? Replacing the motor is also a good idea if the latest esc firmware does not resolve this.
Alex
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@Alex-Kushleyev Thanks for your detailed response. The ESC version is M0134-1. I observed that the correct firmware was loaded. To your point, the NAK was due to the fact that I attempted uploading the wrong firmware version.
The motor Cogging happens on all 4 motors when I rapidly change the thrust input - I noticed this only happens when there are no propellers attached. The issue does not seem to happen when I do the same thrust variations with propellers attached so this might be due to a lack of inertia. As of now, the cogging is no longer present with Propellers attached. I will update the ticket the issue persists after performing additional flight tests.
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@senoa95 ,
Thanks for the update.If you share a short video of the “cogging” without the propellers, i can tell you if that is expected or not.
Also, did you perform the motor calibration foe your motor+prop combination?
Alex
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@Alex-Kushleyev Yes, I can share a video of the motor cogging, but it seems I do not have permissions to upload a video on this forum. I can send you the video if you share an where I can reach you.
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@senoa95 , are you able to use google drive or dropbox or anything similar? We don't have anything set up for uploading videos.
Alex
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@Alex-Kushleyev Can you provide me an EMAIL where I can share the video?
