Added stationkeeping task.

[crvogt]

Added latitude and longitude values to marina.xacro. The values were taken from sandisland.xacro lat/lon.

    <spherical_coordinates>
      <surface_model>EARTH_WGS84</surface_model>
      <world_frame_orientation>ENU</world_frame_orientation>
      <latitude_deg>21.30996</latitude_deg>
      <longitude_deg>-157.8901</longitude_deg>
      <elevation>0.0</elevation>
      <!-- For legacy gazebo reasons, need to rotate -->
      <!--<heading_deg>180</heading_deg>-->
    </spherical_coordinates>

Added vorc topic, though wind speed and direction topics still show VRX. Haven't yet figured out where to add custom topics for wind.

/vorc/debug/contact
/vorc/station_keeping/goal
/vorc/station/keeping/pose_error
/vorc/station_keeping/rms_error
/vorc/task/info
/vrx/debug/wind/direction
/vrx/debug/wind/speed

Modified launch and world files to use cora platform, and marina location.

[mabelzhang]

Custom wind topic can be specified like in this example: https://github.com/osrf/vorc/pull/11

[crvogt]

Custom wind topic can be specified like in this example: #11

Ah okay. Since it occurs in the marina.world.xacro, will that be merged or should I make the change in my own code?

[mabelzhang]

It has already been merged. You should have it if you merge with master. (I haven't done a full review yet, just saw the comment.)

[crvogt]

Thanks, fixed mine! Also combined the two tasks. Though, noticing I should have merged master with my branch and pushed, rather than merged into master :/ ...

[mabelzhang]

Hmm, I'm seeing this PR says it's merged, but the other one says it's closed but not merged? Are you saying both have been combined and pushed into master? It is fine - I can sort it out, just need to make sure I understand correctly.

For future reference, never push to the master branch directly... which sounds like you figured out :) Always make sure you're on a feature branch, and that you only push to the feature branch. The feature branch is reviewed and merged into master only via the GitHub GUI in a pull request, for tractability and visibility.

[crvogt]

Hmm, I'm seeing this PR says it's merged, but the other one says it's closed but not merged? Are you saying both have been combined and pushed into master? It is fine - I can sort it out, just need to make sure I understand correctly.<

Oh, so the only one I meant to merge was the one that I pushed directly to master. The other two PRs I wanted to delete because I'd made the change to include the wind topic and combined both task branches. I thought by closing them I'd avoid deleting the comments and they wouldn't merge.

For future reference, never push to the master branch directly<

Yeah, I figured out that one pretty quick. Mistakenly took 'merge with master' to mean 'merge my code into master'.

Sorry for making more work :/

[mabelzhang]

No worries, my bad for unclear terminology - I think the correct thing I should have said is is merge "from" master.

I'll test out the master branch, probably tomorrow, and open a PR if there's something that needs to be changed. Otherwise thanks for putting in the two tasks!

[mabelzhang]

I was able to test it. Works for me.

To test this task:

$ roslaunch vorc_gazebo station_keeping.launch

Check the pose error:

$ rostopic echo /vorc/station_keeping/pose_error
data: 35.0156621389

Pause Gazebo simulation, move the boat to the red marker by dragging or by entering xy position (41.389682, -360.951298). Check pose error again, and it should be smaller:

$ rostopic echo /vorc/station_keeping/pose_error
data: 1.60657305099