problem with MoveIt + joystick_control.launch

Question

I've created a simple arm and I want to control it using a joystick.

Here's my launch file:

<launch>
  <include file="$(find cougarbot)/cougarbot.launch"/>
  <include file="$(find cougarbot_moveit_config)/launch/joystick_control.launch"/>
  <include file="$(find cougarbot_moveit_config)/launch/move_group.launch"/>
  <include file="$(find cougarbot_moveit_config)/launch/moveit_rviz.launch">
    <arg name="config" value="True"/>
  </include>
</launch>

The error I'm getting is from joystick_control.launch is "[FATAL] Check if you started movegroups. Exiting." Here's the full stack trace:

$ roslaunch cougarbot_moveit_config joystick_control.launch 
[ INFO] [1486692499.658150322]: Loading robot model 'cougarbot'...
[ INFO] [1486692499.659144317]: No root/virtual joint specified in SRDF. Assuming fixed joint
[ WARN] [1486692499.660517007]: Could not identify parent group for end-effector 'hand'
[ INFO] [1486692500.876474349, 182.851000000]: Loading robot model 'cougarbot'...
[ INFO] [1486692500.877637693, 182.851000000]: No root/virtual joint specified in SRDF. Assuming fixed joint
[ WARN] [1486692500.878770531, 182.851000000]: Could not identify parent group for end-effector 'hand'
[FATAL] [WallTime: 1486692501.117867] [0.000000] Check if you started movegroups. Exiting.
Traceback (most recent call last):
  File "/opt/ros/indigo/lib/moveit_ros_visualization/moveit_joy.py", line 42, in <module>
    app = MoveitJoy()
  File "/opt/ros/indigo/lib/python2.7/dist-packages/moveit_ros_visualization/moveitjoy_module.py", line 381, in __init__
    self.updatePlanningGroup(0)
  File "/opt/ros/indigo/lib/python2.7/dist-packages/moveit_ros_visualization/moveitjoy_module.py", line 405, in updatePlanningGroup
    raise rospy.ROSInitException(msg)

rospy.exceptions.ROSInitException: Check if you started movegroups. Exiting.

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Originally posted by danielsnider on ROS Answers with karma: 203 on 2017-02-11

Post score: 0

Answer 1

I found the solution to my own problem.

The warning "[WARN] Could not identify parent group for end-effector 'hand'" led me to add another group to my SRDF. Then joystick_control.launch worked and I could control my robot arm with a joystick!

Specifically, I added this to my arm's SRDF located at "cougarbot_moveit_config/config/cougarbot.srdf".

    <group name="hand">
      <link name="hand" />
    </group>

Here's my full SRDF.

solution: cougarbot_moveit_config/config/cougarbot.srdf
<?xml version="1.0" ?>
<!--This does not replace URDF, and is not an extension of URDF.
    This is a format for representing semantic information about the robot structure.
    A URDF file must exist for this robot as well, where the joints and the links that are referenced are defined
-->
<robot name="cougarbot">
    <!--GROUPS: Representation of a set of joints and links. This can be useful for specifying DOF to plan for, defining arms, end effectors, etc-->
    <!--LINKS: When a link is specified, the parent joint of that link (if it exists) is automatically included-->
    <!--JOINTS: When a joint is specified, the child link of that joint (which will always exist) is automatically included-->
    <!--CHAINS: When a chain is specified, all the links along the chain (including endpoints) are included in the group. Additionally, all the joints that are parents to included links are also included. This means that joints along the chain and the parent joint of the base link are included in the group-->
    <!--SUBGROUPS: Groups can also be formed by referencing to already defined group names-->
    <group name="arm">
        <joint name="fixed" />
        <joint name="hip" />
        <joint name="shoulder" />
        <joint name="elbow" />
        <joint name="wrist" />
    </group> 
    <group name="hand"> <!--added this to fix-->
      <link name="hand" />
    </group>

    <!--END EFFECTOR: Purpose: Represent information about an end effector.-->
    <end_effector name="hand" parent_link="hand" group="arm" />
    <!--DISABLE COLLISIONS: By default it is assumed that any link of the robot could potentially come into collision with any other link in the robot. This tag disables collision checking between a specified pair of links. -->
    <disable_collisions link1="base_link" link2="torso" reason="Adjacent" />
    <disable_collisions link1="base_link" link2="upper_arm" reason="Never" />
    <disable_collisions link1="hand" link2="lower_arm" reason="Adjacent" />
    <disable_collisions link1="hand" link2="upper_arm" reason="Never" />
    <disable_collisions link1="lower_arm" link2="upper_arm" reason="Adjacent" />
    <disable_collisions link1="torso" link2="upper_arm" reason="Adjacent" />
</robot>

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Originally posted by danielsnider with karma: 203 on 2017-02-11

This answer was ACCEPTED on the original site

Post score: 2