How to change the robot_description paramter for the joint_trajectory_controller

edit

You can remap parameter just like topics, so for instance this works:

  <node pkg="robot_self_filter" type="self_filter" name="self_filter">
    <remap from="robot_description" to="robot_description_self_filter" />
  </node>

For ros_control, things might be a little more complicated as the remapping has to be performed for the node, which is the controller_manager that loads a joint_trajectory_controller.

Dear Panda1638

I changed the line of code that you suggest in the joint_trajectory_controller_impl.h file from

urdf::ModelSharedPtr urdf = getUrdf(root_nh, "robot_description");

to

std::string robot_description = "robot_description";
controller_nh_.getParam("robot_description", robot_description);
boost::shared_ptr<urdf::Model> urdf = getUrdf(root_nh, robot_description);

and i specified the robot_description in my controllers .yaml file as so :

boom_robot_arm_controller:
  robot_description: robot_description
  type: position_controllers/JointTrajectoryController
  joints:
....

I recompiled the joint_trajectory_controller pkg and when i try to choose the controller manage ns i get the following error :

Traceback (most recent call last):
  File "/opt/ros/kinetic/lib/python2.7/dist-packages/rqt_joint_trajectory_controller/joint_trajectory_controller.py", line 271, in _on_cm_change
    self._update_jtc_list()
  File "/opt/ros/kinetic/lib/python2.7/dist-packages/rqt_joint_trajectory_controller/joint_trajectory_controller.py", line 243, in _update_jtc_list
    self._robot_joint_limits = get_joint_limits()  # Lazy evaluation
  File "/opt/ros/kinetic/lib/python2.7/dist-packages/rqt_joint_trajectory_controller/joint_limits_urdf.py", line 21, in get_joint_limits
    description = rospy.get_param(key)
  File "/opt/ros/kinetic/lib/python2.7/dist-packages/rospy/client.py", line 465, in get_param
    return _param_server[param_name] #MasterProxy does all the magic for us
  File "/opt/ros/kinetic/lib/python2.7/dist-packages/rospy/msproxy.py", line 123, in __getitem__
    raise KeyError(key)
KeyError: 'robot_description'

This is my robot group namespace in my launch file :

  <group ns="/boom_robot_arm_gazebo">

  <param name="tf_prefix" 
         value="boom_robot_arm_gazebo" />

  <!--   <rosparam file="$(find robot_description)/config/control.yaml" command="load" ns="/robot1" /> -->
  <param name="robot_description" 
         command="$(find xacro)/xacro --inorder $(find boom_robot_gazebo)/urdf/boom_robot_arm_gazebo.xacro"/>

  <!-- Spawning the robot arm initial joint poses don't work because of gazebo_ros_control, maybe in gazebo 11 -->
      <node name="boom_robot_arm_gazebo_spawn" 
            pkg="gazebo_ros" 
            type="spawn_model"
            respawn="false" 
            output="screen"
            args="-urdf -param robot_description  -model boom_robot_arm_gazebo -x 19 -y 0 -z 0.0 -R 0.0 -P 0.0 -Y -1.57079632679 Turret_Joint 0 -J Boom_Joint 0 -J Boom_telesc1_Joint 0 -J Boom_telesc2_Joint 0 -J Rotary_hydraulic_cylinder_Joint 0 -J Basket_Joint 0 -J Chariot_Joint 0 -J Frame_Joint 0 -J Slider_Joint 0 -J Effector_Joint 0">
      </node>

  <!-- convert joint states to TF transforms for rviz, etc -->
  <node name="robot_state_publisher_2" pkg="robot_state_publisher" type="robot_state_publisher"
  output="screen">
  </node>

  <!-- init and start Gazebo ros_control interface for boom_robot_arm_gazebo -->
  <include file="$(find boom_robot_gazebo)/launch/boom_robot_arm_gazebo_control.launch"/> 

  </group>

Can you please help me with this problem. I also tried "robot_description: /boom_robot_arm_gazebo_control/robot_description" in the controllers yaml file.

Thank you