| Note: This tutorial assumes that you have completed the previous tutorials: Basic ROV Usage. |
 Please ask about problems and questions regarding this tutorial on answers.ros.org. Don't forget to include in your question the link to this page, the versions of your OS & ROS, and also add appropriate tags. |
Intermediate ROV Usage
Description: More instructions for using your ROV.Tutorial Level: INTERMEDIATE
ROS Introspection Tools
ROS includes a variety of tools to interrogate a running system. This is a brief overview on a few of them.
rostopic
The rostopic command will list and display ROS network messages from the command line. With the BlueROV core services running, try the follow commands:
rostopic list rostopic hz mavros/rc/override rostopic echo mavros/rc/override
rqt
rqt is a plugin-based framework for GUI widgets. Some of our favorite plugins include:
rviz
rviz fuses many types of information into a 3D world for real-time viewing. An rviz configuration ships with the bluerov package. Try it out like this:
roslaunch bluerov rviz.launch
The pilot and teleop_xbox nodes can be configured while running using the command:
`bash rosrun rqt_reconfigure rqt_reconfigure `
Note that configuration changes during runtime do not persist. Make sure to update the appropriate file in the config/ directory to persist changes.
Saving and Replaying Data
One of the power features of ROS is the ability to record and play back data. Check out the rosbag docs for more info on this.
Exporting Video from ROS Bags
Old process:
# terminal window 1 roscore rosbag play -d 2 something.bag # terminal window 2 mkdir export cd export rosrun image_view extract_images image:=/camera/image _image_transport:=compressed # in terminal window 2 after export has finished cd .. mencoder "mf://export/*.jpg" -mf type=jpg:fps=30 -o output.mpg -speed 1 -ofps 30 -ovc lavc -lavcopts vcodec=mpeg2video:vbitrate=2500 -oac copy -of mpeg 1341 mkdir bag1
Automatically Start ROS On Bootup
To automatically launch ROS on startup, install robot_upstart and then run:
rosrun robot_upstart install bluerov/launch/bluerov_r1.launch
Manually control the upstart job with these:
sudo service bluerov start sudo service bluerov stop
Check the log like this:
sudo tail /var/log/upstart/bluerov.log -n 30
Preparing for a Mission
If you don't have a body of water within a couple of feet of your workstation, performing a wet test can turn into a big ordeal. Here is a checklist of items that we use to ensure everything is good to go before leaving for a wet test or actual mission.
Before you head out for a wet test, make sure that you do as much preparation as possible ahead of time. In particular, attempt to exercise the complete functionality of the ROV as much as possible before heading out for the test.
Mission Checklist
Here is a sample list of what to bring on a mission.
Item |
Notes |
ROV |
dry-run motors, teleop control, and camera ahead of time |
ROV batteries |
check charge |
external camera(s) |
check charge |
teleop controller |
check charge and don't forget wireless dongle if applicable |
workstation/laptop |
check charge |
weights |
to fine-tune buoyancy |
silicone grease |
to keep o-rings and penetrators lubricated |
other tools |
cause you never know |
a towel |
to dry things off |
replacement parts |
to replace something if it breaks |
