Fix an existing URDF file so it works with pybullet

We are looking for an experienced freelancer to debug and enhance a URDF (Unified Robot Description Format) file. The current URDF file loads fine in URDF Viz but fails to load in PyBullet. Your task will be to ensure that the URDF file:

1. Loads correctly in PyBullet and renders without issues.
2. Allows moving joints to function in PyBullet as they do in URDF Viz, without joints becoming detached.
3. Ensures robot joints have limits enforced, similar to those in URDF Viz.

Requirements:

• Ensure the URDF file loads correctly in PyBullet.
• Ensure moving joints succeed in PyBullet, similar to URDF Viz, without joints becoming detached.
• Ensure robot joint limits are enforced, using the same limits as in URDF Viz.
• Provide a Python demo code that demonstrates the successful loading and operation of the URDF file in PyBullet.

Additional Information:

• Current Issues: Incorrect physics behavior, parts not loading correctly in PyBullet.
• Robot Components Described: Mechanical joints, actuators.

Deliverables:

1. A corrected URDF file that meets the above requirements.
2. Python demo code to demonstrate the URDF file’s successful loading and operation in PyBullet.