Build the base of the robot with four wheels by creating a file in the chapter6_tutorials/robot_description/urdf folder with the name mobile_robot.urdf, and add the following code:
<?xml version="1.0"?> <robot name="mobile"> <link name="base_link"> <visual> <geometry> <box size="0.2 .3 .1"/> </geometry> <origin rpy="0 0 0" xyz="0 0 0.05"/> <material name="yellow"> <color rgba="255 255 0 1"/> </material> </visual> <collision> <geometry> <box size="0.2 .3 0.1"/> </geometry> </collision> <inertial> <mass value="100"/> <inertia ixx="1.0" ixy="0.0" ixz="0.0" iyy="1.0" iyz="0.0" izz="1.0"/> </inertial> </link> <link name="wheel_1"> <visual> <geometry> <cylinder length="0.05" radius="0.05"/> </geometry> <origin rpy="0 1.5 0" xyz="0.1 ...
