Robotic arm fall to ground in gazebo

Question

I create a custom URDF in Solidworks and simulate it in ROS when ever I launch the robot in the gazebo simulator the arm fall to the ground. the robot is perfectly fine in rviz.

Answer 1

That is because you are not sending any signals to the joints, so it is behaving as links connected to a movable joint that is not powered. You need to:

Define the joints as fixed joints as

    <joint name="footprint" type="fixed" >
        <parent link="base_footprint" />
        <child link="base_link" />
        <origin xyz="0 0 0.05" rpy="0 0 0" />
    </joint>

or add a controller to your system as described here.

Follow the Gazebo ROS Control to add those to your system and be able to interact with your joints via the joint_state_publisher topic.