urdf-robot-model

A URDF robot model requires each link to include visual geometry, collision shapes, and inertial properties, with joints properly defined by type and axis. Create links with three-element definitions, compute inertia using standard formulas, specify joint origins in radians, then validate with check_urdf and visualize in RViz or Gazebo.

Each URDF link must contain three components: visual geometry for display, collision shape for physics calculations, and inertial data specifying mass and moment of inertia. All three elements are required for realistic simulation and proper dynamics behavior in Gazebo or other simulators.

Use check_urdf to validate URDF syntax and structure, then visualize the model in RViz to confirm geometry, joint placement, and coordinate frames are correct. Common mistakes include missing inertial data, incorrect joint axes, or rotation values not in radians—all detectable through these debug steps.

Yes, xacro modularity supports reusable URDF definitions by allowing macros, parameters, and includes. This approach reduces duplication across similar links and joints, making large robot models easier to maintain and update.

URDF is compatible with both Gazebo for physics simulation and RViz for visualization. Both tools read the same URDF format, though Gazebo requires complete inertial properties and collision geometries for accurate dynamic simulation.