RTPS_TRANSPORT_SHM ERROR

[likemountain]

Hello,

I was able to launch the odrive_bringup, but I see this error message when I publish the velocity command.

It's kind of weird because my motor is moving when publishing a really high number as my velocity, but the velocity is not constant. It's kind of jerking. It repeats rotating fast and slow. I wonder if this is because of the error message or because my control gains are wrong.

Does anybody know how to resolve this issue?

[borongyuan]

Hi,

I haven't seen this error message before. It looks like a DDS related issue.
The velocity problem is a bit odd, as jerking usually occurs at low speeds rather than high speeds. The topic frequency is different from the odrive command frequency. The latter is defined in the yaml file and should preferably match the control bandwidth. Did you encounter similar issues when sending commands using odrivetool?

[likemountain]

The velocity problem is resolved after tuning my control gains, but I still see the RTPS_TRANSPORT_SHM ERROR message from time to time. Should I worry about this error message?

[borongyuan]

I'm not sure. Fast DDS (formerly Fast RTPS) is used as the default DDS vendor by ROS Foxy. So this is what I mainly use. I've been working from home recently and don't have odrive board on hand. I don't know if recent updates of some packages have an impact. It might be related to these two issues.
eProsima/Fast-DDS#2003
eProsima/Fast-DDS#2099