Virtual Joint/World Joint not working with Gazebo
Hello friends,
I am unsure of where this post belongs as I posted something similar in the ROS Answers and did not get much attention that side.
I am attempting to correctly fix my gazebo model to the empty world as I have seen in so many tutorials (like this one), but am struggling...a lot.
My GitHub for the project can be found here...where I am attempting to launch demo_gazebo.launch
but get a similar behavior as this previously asked question: 22078.
I have attempted both the solutions there with no luck.
The URDF being utilized is here.
I have tried several iterations with and without the "world" link (truncated URDF):
<?xml version="1.0" ?>
<!-- =================================================================================== -->
<!-- | This document was autogenerated by xacro from arm.xacro | -->
<!-- | EDITING THIS FILE BY HAND IS NOT RECOMMENDED | -->
<!-- =================================================================================== -->
<robot name="arm" xmlns:xacro="http://www.ros.org/wiki/xacro">
<!-- base_link -->
<gazebo reference="base_link">
</gazebo>
<!-- plat_link -->
<gazebo reference="plat_link">
</gazebo>
<!-- lock_link -->
<gazebo reference="lock_link">
</gazebo>
<!-- shoulder_link -->
<gazebo reference="shoulder_link">
</gazebo>
<!-- forearm_link -->
<gazebo reference="forearm_link">
</gazebo>
<!-- wrist_link -->
<gazebo reference="wrist_link">
</gazebo>
<create/>
<gazebo>
<plugin filename="libgazebo_ros_control.so" name="gazebo_ros_control">
<robotSimType>gazebo_ros_control/DefaultRobotHWSim</robotSimType>
<legacyModeNS>true</legacyModeNS>
</plugin>
</gazebo>
<!--World Link-->
<link name="world"/>
<!-- World Joint -->
<joint name="world_joint" type="fixed">
<parent link="world"/>
<child link="base_link"/>
</joint>
<!--Base Link-->
<link name="base_link">
<inertial>
<mass value="1.0"/>
<origin rpy="0 0 0" xyz="0 0 0"/>
<inertia ixx="0.00153508333333" ixy="0" ixz="0" iyy="0.00153508333333" iyz="0" izz="0.00245"/>
</inertial>
<collision>....................................................
I realize this is probably a one line quick fix but I am so stumped and I really want my custom 4 DOF shakin' before June!
Any time you fine people can give is greatly appreciated.
m
Asked by matthewmarkey on 2020-05-19 03:56:35 UTC
Answers
Hi,
Adding these lines at the end of the URDF should be enough
<link name="world"/>
<joint name="world_joint" type="fixed">
<parent link="world"/>
<child link="dummy_link"/>
</joint>
Asked by ahcorde on 2020-05-19 09:48:43 UTC
Comments
Hey @ahcorde, thank you for checking out my question, I appreciate your time.
In my quest to solve this, I have tried your suggestion as well. I have updated the URDF and the SRDF in my project in a form that I feel should be the solution.
When this is run, the arm acts erratically in both Gazebo and Rviz/Moveit.
Asked by matthewmarkey on 2020-05-20 06:32:44 UTC
Whenever I use the lines of code you have suggested, my model moves very quickly in many different directions.
Asked by matthewmarkey on 2020-05-20 06:35:24 UTC
Comments