Is there any way to calculate inertial property of a robot to simulate it in Gazebo

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I implemented a python script reading an 3D file like stl or dae and outputting the full URDF XML inertial tag based on the gazebosim tutorial. and pymeshlab.

At first the script calculates the center of mass of the object. After that it scales the mesh by a factor of 100 to increase the numerical accuracy. You could manually change that, if you need to scale it more up. Now the convex hull of your object will be calculated. For the hull the geometric properties will be calculated, scaled back down and outputted as URDF XML inertial tag like that (the precision could also be changed in the script)

<inertial>
  <origin xyz="0.00000002 -0.00000001 0.00000000"/>
  <mass value="5.00000000"/>
  <inertia ixx="7.90866056" ixy="0.00000006" ixz="0.00000000" iyy="7.90866060" iyz="0.00000000" izz="2.48398783"/>
</inertial>

Check it out here: https://github.com/vonunwerth/MeshLab...

I know that SolidWorks can calculate this value for you, and I'm assuming that any other CAD program can as well.

As a general rule of thumb, I try to follow a number of guidelines when creating urdf models. These are mostly based on experience, so they should only be taken for what they are.

1. Don't make objects too large
2. Don't make objects too small
3. Avoid modifying the gravity
4. Keep masses for dynamic objects as close as possible. (i.e. the simulator will not like it if you place a 1000kg weight on four 1kg wheels.
5. When in doubt, use the identity mass moment of inertia <1 0 0 1 0 1>

You might also want to try the following to make your links more "solid":

<gazebo reference="back_left_wheel">
  <kp>1000000.0</kp>
  <kd>1.0</kd>
</gazebo>