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robot_description not found on parameter server while launching the controller.

asked 2022-03-05 14:15:12 -0600

aarsh_t gravatar image

Hello everyone, I have one own created controller for one crane arm. Here you can find the necessary information from controller yaml file,

    - neck_L_j1
    - arm_j1_j2
    - arm_j2_j3
  sim_control_mode: 1 # 0: position, 1: velocity

# Publish all joint states -----------------------------------
    type: joint_state_controller/JointStateController
    publish_rate: 500  

     type: effort_controllers/JointGroupPositionController
       - neck_L_j1
       - arm_j1_j2
       - arm_j2_j3

       pid: {p: 3000.0, i: 1.0, d: 0.01}
       pid: {p: 3000.0, i: 1.0, d: 0.01}
       pid: {p: 3500.0, i: 1.0, d: 0.01}

I have created the controller launch file which contains the following information.

<?xml version="1.0"?>
<group ns="/robot1">
    <rosparam file="$(find crane_arm_controller_robot1)/config/crane_arm_controller.yaml" command="load" />

    <arg name="controllers" default="joint_state_controller crane_left_eff_pos_controller" />

    <!-- Loads the controllers -->
    <node name="leftArm_controller_spawner" pkg="controller_manager" type="spawner"
    output="screen" args="$(arg controllers)"/>

I have same namespace into urdf file as well while loading the plugin.

    <plugin name="gazebo_ros_control" filename="">

Now whenever I launch the module, I have robot_description param loaded as /robot1/robot_description so controller should be able to find it but that is not the case with me. it gives the following error.

[ERROR] [1646509768.321224385]: Could not find parameter robot_description on parameter server
[ERROR] [1646509768.321700089]: Failed to parse urdf file
[ERROR] [1646509768.321938019]: Failed to initialize the controller
[ERROR] [1646509768.322140682]: Initializing controller 'crane_left_eff_pos_controller' failed
[ERROR] [1646509769.337931]: Failed to load crane_left_eff_pos_controller

Now here comes the best part, Everything runs smoothy when I have robot_description param loaded as /robot_description. On top of that if I do not use effort_controllers/JointGroupPositionController and use effort_controllers/JointPositionController for individual joints, the controller identify the robot_description loaded into namespace /robot1/robot_description

Please let me know if you know some way to solve this. If you want more information on the issue, please let me know.

Thank you.

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answered 2022-03-06 07:50:17 -0600

aarsh_t gravatar image

It was an issue with the ros_controllers package, I have modified the relevant file and opened a PR, in the mean time it get accepted, you can use building from source with my repo.

Here is the link to PR.

And here is the link to the updated repo.

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Asked: 2022-03-05 14:15:12 -0600

Seen: 377 times

Last updated: Mar 06 '22