ROS2 URDF — Debug a Broken Robot Description

Easy URDF 82% pass rate
#urdf#robot-description#xml#validation

Practice the ROS2 URDF — Debug a Broken Robot Description coding problem in URDF. Browser-based execution with automated grading — no local ROS install required. 82% of engineers pass this challenge.

Problem Statement

A URDF file has been given to you with 4 deliberate errors. Your task is to find and fix every error by editing robot.urdf directly.

solution.py loads and validates your URDF automatically — run it after each fix to see which errors remain.

The 4 Error Types Hidden In This URDF

# Error Type What To Look For
1 Link name typo A link name has a spelling mistake
2 Invalid joint type A joint type attribute is misspelled
3 Broken parent reference A joint references a parent link that doesn't exist
4 Broken child reference A joint references a child link that doesn't exist

What A Fixed URDF Must Have

  • base_link and arm_link defined correctly
  • shoulder_joint (revolute) with base_link as parent and arm_link as child
  • elbow_joint (fixed) with arm_link as parent — add a forearm_link to make it valid
  • All joint types from the valid set: revolute, fixed, continuous, prismatic
  • No broken parent/child references

Input/Output Format

You edit: urdf/robot.urdf Do not edit: solution.py

Expected output when all errors are fixed:

[PASSED] All 4 errors fixed — URDF is valid with 3 links and 2 joints

⚠️ Common Pitfalls

  • Read each [FAILED] message carefully — it tells you exactly which link or joint has the problem
  • Fix one error at a time and re-run to confirm
  • When you fix a link name typo, you must update all references to that link in joints too

📚 Helpful Resources

Frequently asked questions

What is the ROS2 URDF — Debug a Broken Robot Description practice problem?

It is a hands-on URDF challenge on SimuCode where you implement and run ROS2 code in the browser with runtime-verified tests.

How do I practice ROS2 URDF — Debug a Broken Robot Description online?

Open this page, sign in, and solve the problem in the built-in IDE. Your solution is graded against real ROS2 execution checks.

What skills does ROS2 URDF — Debug a Broken Robot Description test?

This Easy problem focuses on urdf, robot-description, xml skills used in robotics interviews and production systems.