ROS2 Manipulation Basics - demo 1.1 not working

I am attempting the " ROS2 Manipulation Basics" course. The very first step is Demo 1.1, but I can’t get that working. I am able to start the action bridge in Shell #1, but when trying to make available to ROS2 the ROS1 topics by running the “roslaunch load_params load_params.lauch” command, it fails. If I then continue on with the next step (starting MoveIt in ROS2) anyway, nothing happens.

Output when running the roslaunch command as follows:

user:~$ roslaunch load_params load_params.launch
... logging to /home/user/.ros/log/2e90e84c-7a53-11ec-bd71-0242ac140008/roslaunch-1_xterm-6326.log
Checking log directory for disk usage. This may take a while.
Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.

started roslaunch server http://1_xterm:35067/


 * /rosdistro: noetic
 * /rosversion: 1.15.11
 * /topics: [{'topic': '/join...



No processes to monitor
shutting down processing monitor...
... shutting down processing monitor complete

Any suggestions what I am doing wrong?

Hi @Geoff_S , you are actually not doing anything wrong.

The load_params.launch only loads the topics you want to bridge as ROS parameters, and then it dies. If you want to see what it did, then in that same terminal you can run rosparam get /topics. You should see a list of topics generated by load_params.

Once you have them ready, you have to launch the parameter_bridge, in addition to the action bridge in Shell#1. So the process would be:

  1. Shell 1: Action bridge. Make sure that it is working by going to another terminal and typing ros2 action list
  2. Shell 2: Source ROS1 and launch load_params.launch
  3. Shell 3: Run the parameter_bridge:
source /opt/ros/noetic/setup.bash
source /opt/ros/foxy/setup.bash
ros2 run ros1_bridge parameter_bridge
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Thanks for the reply and suggestions. After a while I guessed the load_params was perhaps meant to die after executing. I’m not sure why I then had problems with Moveit in the remaining steps, but I re-tried a couple of times and managed to get it working as intended. Thanks again for the help.

I have come across a subsequent small bug with the instructions. The notes for the next exercise “Create a Moveit2 Package” includes the following:

As you may have noticed from the launch file, you are loading a XACRO file named **ur3e_robot.urdf.xacro**, from the package **ur_e_description**, which is supposed to contain the definition of your robot. However, this package or file is nowhere to be seen in your ROS2 workspace.
Download this package with the following command:
Execute in Shell #1

cd ~/ros2_ws/src git clone
# Some extra dependencies 
git clone

However the default branch for the grasping_msgs repo is for ROS1, so the colcon build will fail. Need to specify the ROS2 branch instead:

git clone -b ros2`

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