felixmaisonneuve
commented
3 years ago Hi @civerachb-cpr,
I am not sure I understand everything in your question, so I will try to answer it the best I can.
First, you seem to have trouble getting the robot_description. In kortex_arm_simulation.cpp, the robot_description is found using the hardcoded path "/" + m_robot_name + "/robot_description". This is because in our launchfile (kortex_driver.launch) we have something like
<param name="robot_description" command="$(find xacro)/xacro --inorder $(find kortex_description)/robots/$(arg arm).xacro dof:=$(arg dof) vision:=$(arg vision) sim:=false"defined within the robot_name namespace (<group ns="$(arg robot_name)">). This will publish the robot_description in "/m_robot_name/robot_description".
I don't see where you publish your robot_description using your xacro file. I think you should have something like
<group ns="$(arg robot_name)">
<!-- Load robot description -->
<param name="robot_description" command="$(find xacro)/xacro ...
<!-- Start the kortex_driver node -->
<node name="$(arg robot_name)_driver" pkg="kortex_driver" type="kortex_arm_driver" output="screen"> <!--launch-prefix="gdb -ex run args"-->
<param name="sim" value="$(arg sim)"/>
<param name="ip_address" value="$(arg ip_address)"/>
...Second, you mentionned kortex_arm_simulation.cpp is starting Moveit, which is not the case (or at least I don't see anything related to moveit in kortex_arm_simulation.cpp).
In our launch file (kortex_driver.launch) however, we do have 2 arguments (start_rviz and start_moveit) that are set to true by default. These two will start the simulation by launching ...$(arm)_moveit_config/launch/move_group.launch. So, unless you set those to false when launching the driver (e.g. roslaunch kortex_driver kortex_driver.launch start_rviz:=false start_moveit:=false) it will automatically launch the simulation.
I am not sure what you are trying to achieve with the sim argument.
civerachb-cpr
yj-Tang
dfalveargOT
RX-00
DavidPaulBenjamin
A common use case (for us anyway) is mounting the Gen3 or Gen3 Lite onto a mobile robot platform (e.g. Clearpath's Jackal, Dingo, or Husky). Unfortunately, it appears to be impossible to run a complete simulation of the arm and mobile platform because of some issues inside kortex_arm_simulation.cpp:
1) The robot_description path is hard-coded. When mounting the arm on the real robot, we modify the base robot's URDF to include the arm macro. For example on a Dingo with a Gen3 Lite arm we would use https://github.com/dingo-cpr/dingo_manipulation/blob/main/dingo_kinova_description/urdf/dingo_gen3_lite_description.urdf.xacro to attach the arm to the robot. This results in the robot description parameter being /robot_description, but https://github.com/Kinovarobotics/ros_kortex/blob/eef6758e901d408df5656bb16edc5bd00534d6f9/kortex_driver/src/non-generated/driver/kortex_arm_simulation.cpp#L60 hard-codes the path to be
/<arm-name>/robot_descriptionwhich does not exist in this use-case, and there's no way to modify this path without needing to recompile the driver.2) Even if we do change the
model.initParamline in kortex_arm_simulator.cpp, the fact that this class also tries to launch MoveIt and find planning groups causes the driver to crash anyway. We don't want to launch Moveit as part of the simulated driver; we just want to be able to get the joint states publishing correctly. We can launch Moveit ourselves (e.g. using https://github.com/dingo-cpr/dingo_manipulation/blob/main/dingo_gen3_lite_moveit_config/launch/move_group.launch) -- again, there doesn't appear to be any way to disable auto-launching Moveit without making some major changes to the driver and recompiling it.Is there a different node I should be launching to launch a simulated arm driver that just launches the core driver with a configurable robot_description path and without automatically starting Moveit planning groups? The launch file I'm using to start the arm is this:
with the
simparameter set totrue. This same launch file works properly on a physical robot (with thesimparameter set tofalse). My goal is to be able to have the simulation and real robot work as-similarly as possible. If I need to use a different node than thekortex_driver/kortex_arm_driverinstead, what node should I use instead?