Add corrections (AR tags) to EKF
I'm using the EKF of the robot_localization package. The inputs of the EKF would be just the IMU or maybe the IMU and an odometry (using a visual odometry package, but I couldn't make it work well, so maybe I don't use it).
But, when a predefined AR tag is in the FOV of my quadcopter, using the ar_track_alvar package I have the relative position and orientation of my quadcopter (i.e, the position and orientation in the tag frame).
I need to add the information provided by the tag detector, when it exists. And, when it exists, that information is discrete.
I don't know how to do that but I think that what I have to do is to store the relative pose (position+orientation) in a specific topic. When there's information, I store that information. When there's no information, I store an error message so I know that I don't need to use that information. Is that correct?
But now, how can I add that information to the robot_localization package? It would be something similar to the GPS data, but the package only talks about the GPS data, not data provided by a tag detector, for example.
I hope someone can help me. I really need to make this work. Thanks!