Hello everyone!

i am currently working on a project where I am trying to implement a RecoveryFallback node in Nav2 in python. My goal is to let the robot search for apriltags autonomously in case it loses its position. I already wrote the action server that drives autonomously for as long as it doesn't receive "apriltag found" within a topic. I am using the apriltag detector of christianrauch and wrote a node (update_pose), that computes the robot's pose with the information of the apriltag node and a yaml file, that contains the apriltags position in the coordinate system. This node is suppose to publish data to a topic to let the action server know that an apriltag has been found and what the position of the turtlebot is.

My issue is that I have no idea how to start the apriltag and update_pose node when the action should be run. I only want both nodes to run as long as the action is running. Or do i have to start each node separately when i am using navigation?

Thank you so much in advance!