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BT-Navigator transition error

asked 2021-12-18 07:27:17 -0500

HarunTeper gravatar image


I am currently working on a multi-robot simulation, you can find the package here:

When I try to launch multiple robots with the navigation stack (only localization and navigation, no slam), I get the following transition error link.

This error can be replicated by building the package and running the following command:

ros2 launch car_simulator

What changes do I have to apply to my launch setup, so that the navigation components are properly setup?

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answered 2021-12-18 11:49:31 -0500

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That appears to be your error, I’d look into why that’s being a problem, which is in turn failing the lifecycle transition causing the Lifecycle Manager / BT Navigator issue.

I’d also use the CLI to verify everything is namespaced with robot0/1 properly, but from the logs it looks correct to me. Could also just be an issue with node name collisions when the manager is trying to transition up a server of the same name that was already up from the other robot’s manager.

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I found the source of the error. I am using ROS2-Foxy for this package. In the file bt_navigator.cpp, in line 181+, if I disable "addGrootMonitoring", the error does not occur and I can control both cars.

HarunTeper gravatar image HarunTeper  ( 2021-12-20 10:33:48 -0500 )edit

That makes sense, the fix for multiple ZMQ port options was made in galactic or newer. We couldn’t backport due to the fix requiring ABI breaking changes. Turning Groot monitoring off would entirely fix the issue related to creating multiple ZMQ client instances in a single process.

stevemacenski gravatar image stevemacenski  ( 2021-12-20 19:37:54 -0500 )edit

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Asked: 2021-12-18 07:27:17 -0500

Seen: 240 times

Last updated: Dec 18 '21