imc_ros_bridge

Minimal library for bridging ROS and IMC messages

Building

A simple catkin_make should do.

Launching

The command

roslaunch imc_ros_bridge bridge.launch server_addr:=127.0.0.1 server_port:=6002

will launch the imc_bridge node.

ROS to IMC conversion and use on vehicles

See the vehicles documents.

Trying with Neptus

These instructions have been tested for Ubuntu 16.04, 18.04, 20.04. For 18.04 and 20.04, you may have to comment a line in a jdk file to get it running (See Troubleshooting).

First, install dependencies: sudo apt install openjdk-11-jdk. Second, make sure there are no other Javas in your system, you might have a jre-default installed by default. Use apt remove ... to remove it (See Troubleshooting for more details).

Clone and build Neptus at a known-working commit:

git clone https://github.com/LSTS/neptus.git
git checkout 38c7f41a9885c6b059f79b38861edb4b7b67511b
cd neptus
./gradlew

If successful, run it with ./neptus. As of Mar 2 2021, this will open up a map view and you should see the vehicles in this map. (Neptus is being actively developed nowadays, so things might change, contact @KKalem if need be)

If you go to the systems list panel (top bar: view), you should also see the ROS auv displayed as a cyan panel. This indicates that neptus can communicate with the auv. Any other color indicates som problem, see this link.

For SMaRC Vehicles:

Delete the neptus/vehicle-defs folder and copy imc_ros_bridge/vehicle-defs into neptus/ instead (You could also merge the two instead of replacing). This way, in Neptus, you will (only) see SAM and LOLO as options and Neptus will know the maneuvers they are capable of. You will need to update these files manually if they ever change in the future. (As of Mar 2 2021, the vehicle-files are not used because the 'main window' of Neptus no longer exists, this might change in the future)

Troubleshooting

If Neptus does not seem to work, try these: On Ubuntu 18.04 and 20.04, you might have openjdk-11-jre-headless and default-jre remove them with apt remove ... manually and make sure that apt list --installed | grep jre only shows one jre, it should look like this:

$ apt list --installed | grep jre

WARNING: apt does not have a stable CLI interface. Use with caution in scripts.

openjdk-8-jre-headless/focal-updates,focal-security,now 8u282-b08-0ubuntu1~20.04 amd64 [installed,automatic]
openjdk-8-jre/focal-updates,focal-security,now 8u282-b08-0ubuntu1~20.04 amd64 [installed,automatic]

This is a known-working setup as of Mar 2 2021.

Additionally, if you get a "No VTK Java Packages Found" message in Neptus's console AND things are not working, do this(might need to change the java version to the version you have):

sudo vim /etc/java-8-openjdk/accessibility.properties Comment out the following line: assistive_technologies=org.GNOME.Accessibility.AtkWrapper

If you get an error that involves iced-tea in the Neptus terminal window when you try to open a console, check that you have openjdk-8-jre. Not just the headless version of it, Neptus needs the head.

Existing conversions

ros_to_imc

• std_msgs::Empty on topic /heartbeat -> IMC::Heartbeat
• sensor_msgs::NavSatFix on topic /gps_fix -> IMC::GpsFix
• geometry_msgs::Pose on topic /goto_input -> IMC::Goto
• sensor_msgs::NavSatFix on topic /gps_nav_data -> IMC::GpsNavData
• sensor_msgs::NavSatFix on topic /estimated_state -> IMC::EstimatedState
• imc_ros_bridge::PlanControlState on topic plan_control_state -> IMC::PlanControlState

imc_to_ros

• IMC::Goto -> geometry_msgs::Pose on topic /goto_waypoint
• IMC::Abort -> std_msgs::Empty on topic /abort
• IMC::Heartbeat -> std_msgs::Empty on topic /imc_heartbeat
• IMC::PlanDB -> std_msgs::String on topic /plan_db (JSON)
• IMC::Plancontrol -> imc_ros_bridge::PlanControl on topic /plan_control

Creating new conversions

For each conversion in either direction, you need to create a new library that contains a specialized convert function for the types you want to convert. You then need to add a BridgeServer to the node, see details below.

ros_to_imc

Check out examples in the include/imc_ros_bridge/ros_to_imc and src/ros_to_imc folders for more examples. All conversions specialize the convert function like this:

namespace ros_to_imc {
template <>
bool convert(const sensor_msgs::NavSatFix& ros_msg, IMC::GpsFix& imc_msg)
{
    imc_msg.lat = ros_msg.latitude;
    imc_msg.lon = ros_msg.longitude;
    imc_msg.height = ros_msg.altitude;

    return true;
}
}

And they also add the bridge server to the bridge_node like this:

ros_to_imc::BridgeServer<sensor_msgs::NavSatFix, IMC::GpsFix> gpsfix_server(ros_node, imc_handle, "/gps_fix");

And link the convert libary into ros_to_imc_node in the CMakeLists.txt file.

imc_to_ros

Check out examples in the include/imc_ros_bridge/imc_to_ros and src/imc_to_ros folders for more examples. All conversions specialize the convert function like this:

namespace imc_to_ros {
template <>
bool convert(const IMC::Goto& imc_msg, geometry_msgs::Pose& ros_msg)
{
    ros_msg.position.x = imc_msg.lon;
    ros_msg.position.y = imc_msg.lat;
    ros_msg.position.z = imc_msg.z;
    return true;
}
}

And they also add the bridge server to the bridge_node like this:

imc_to_ros::BridgeServer<IMC::Goto, geometry_msgs::Pose> goto_server(imc_handle, ros_node, "/goto_waypoint");

And link the convert libary into imc_to_ros_node in the CMakeLists.txt file.

Neptus-AUV Integration

For some vehicle named $VEHICLE. In this repo, we have three vehicles available: sam-auv, lolo-auv and imc_ros_bridge.

IMPORTANT NOTE

The bridge should be running on the same physical device as Neptus. This is a current limitation due to IP address shenanigans that is planned to be fixed eventually. Both for physical and simulated vehicles, Neptus and bridge must run on the same device.

Adding a vehicle to Neptus

An arbitrary integer $NUMBER is used by Neptus as a convention to group together similar vehicles.

Copy neptus_vehicle_definitions/$VEHICLE_files/$NUMBER-$VEHICLE.nvcl into .../neptus/vehicle-defs/ and neptus_vehicle_definitions/$VEHICLE_files/$VEHICLE folder into .../neptus/vehicle_files/. This will add $VEHICLE to the list of vehicles available in Neptus' list, with $VEHICLE's visuals.

Do the same thing with imc_ros_bridge to get a generic vehicle. The imc_ros_bridge fake vehicle has id 4.

When starting the imc_ros_brdige node, be careful to set the imc_id parameter to the correct one, otherwise the bridge will not receive data from the respective console window. Do not forget to select the correct vehicle in the console window (top right, drop down menu) either.

The .nvcl file contains the id of the vehicle you are adding. You can find the imc-id field under <communication-means> -> <comm-mean> -> <protocols-args> -> <imc>. This field should be changed to whatever imc id you might want to use. It also must match the imc_id parameter used by the bridge node.

For advanced uses of the .nvcl file, consult Neptus documentation.

Moving a vehicle around

Using the console (opened by going to Vehicles -> $VEHICLE -> click console button) generate a plan (In the console window: Tools -> Generate plan or use the plan tool on the left). Select the plan on the right section of the console and click the blue arrow (upload button) towards the top. This will create and send out a JSON formatted plan to the ros topic /plan_db. Parse this JSON on the vehicle, and control $VEHICLE.

In order to see the updated pose of $VEHICLE in the Neptus console, publish to the ros topic /estimated_state. Currently only lat, lon, altitude are used. The update rate on the Neptus console can be about once every 1-2 seconds, be patient.

See this tutorial for a demo that uses this bridge as part of a full planning -> execution pipeline in simulation.

Emergency

From the Neptus console, the big red ABORT button can be used to send an empty message to the ros topic /abort. Probably a good idea to subscribe to this topic. Disregard the errors that pop out in the Neptus console due to missing acoustic transponders and such.