add option to send goal(s) from bridge

[padhupradheep]

currently there is no option to specify an goal for the robot using the bridge or through RViz

[padhupradheep]

This hold true for ROS and ROS 2..

[neojaw]

The Pilot planners used to listen for goals on topic navigation.new_goal_pose. I removed it at some point because it got in the way of something and I thought it was unnecessary. I only later realized it was meant for the ROS bridge.

The import in the bridge is still there and working, so this is actually a Pilot issue.

[padhupradheep]

Well, from the RViz of both ROS and ROS 2, it is not possible to send any goals to the pilot. The only way possible right now, is to use the /move_base/goal topic in the application code. But that holds true only for ROS 1. In ROS 2, the goals from RViz and the application code is routed only through the action servers, which again needs to be addressed for pilot in #11.

Edit: Action servers are only for Nav2. See the below comment for more info.

[padhupradheep]

Okay, digging bit deep. I think for ROS 2 it make sense to use the publishers for sending the goal to Pilot. There is a rviz tool for setting goal. This tool publishes the goal in the topic type of geometry_msgs/PoseStamped. So, in the configs, we already have the topic /move_base_simple/goal. Just need to rename it and we are good to go.

Somewhere in the future, we can try bridging Nav2 and Pilot (definetely only on request).

@neojaw is it possible for you to ad the new_goal_pose topic back in pilot ? and also if user wants to send multiple goals, could we also have a pose_array topic ?

[neojaw]

I can add the new_goal_pose topic again. The pose_array thing should also be possible but requires a new translation in the bridge, of course. What ROS data type would that be?

[padhupradheep]

In Nav2, we use an array container, something like this geometry_msgs/PoseStamped[] poses. Would it be possible do the same here?

[neojaw]

We can make that work, yes.

Edit: I guess it would be geometry_msgs/PoseArray then. Can be easily translated into Pilot's PoseArray2D.

[neojaw]

Ok, turns out, we removed the new_goal_pose from the planners, but added it to the PilotServer module which relays it to the planners. So at least a single goal should already work. @padhupradheep Can you try that?

[padhupradheep]

Edit: I guess it would be geometry_msgs/PoseArray then. Can be easily translated into Pilot's PoseArray2D.

I think this is different. PoseStamped[] has stamps for each poses and PoseArray has one stamp for all the poses. I would have prefered to use the former because of the fact that Nav2 uses it and would be easy to bridge Nav2 and Pilot later. But for the sake of easy translation, we can go for PoseArray for now.

Can you try that?

Yes, will do that!

[padhupradheep]

By any chance, is the status of the Goals are exposed ?