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Cheat Sheet

Debugging Tips

Common issues and how to fix them: sensors, transforms, latency, URDF

Sensor Data Not Arriving
  1. Verify the sensor driver process is running
  2. Check physical connections (USB, serial, Ethernet)
  3. Confirm baud rate / port settings match the hardware
  4. Look for permission issues (e.g. /dev/ttyUSB0)
  5. Check if the sensor requires a warm-up period
Transform / Frame Errors
  1. Visualize the full transform tree to find missing links
  2. Check for duplicate publishers broadcasting the same frame
  3. Ensure timestamps are synchronized across all nodes
  4. Check for extrapolation errors (timestamps in the future)
  5. Verify URDF has correct parent-child relationships
Simulation Clock Issues
  1. Configure all nodes to use simulation time
  2. Verify the clock topic is being published
  3. Check that simulation time is actually advancing
  4. Ensure the simulator process is running and not paused
  5. Check for real-time vs. sim-time mismatches
High Latency / Slow Performance
  1. Check CPU usage — is one process pegging a core?
  2. Reduce image resolution or use compressed transport
  3. Use lossy delivery for high-frequency sensor streams
  4. Profile message frequencies and bandwidth usage
  5. Consider zero-copy transport for large messages
URDF / Robot Model Issues
  1. Validate XML syntax with check_urdf model.urdf
  2. Ensure all mesh file paths are correct
  3. Check inertia values are reasonable (not all zeros)
  4. Verify joint limits and effort/velocity limits
  5. Confirm the kinematic chain is connected (no orphan links)
Path Planning Failures
  1. Check that the costmap is being updated correctly
  2. Verify start and goal poses are in free space
  3. Increase planner timeout if the environment is complex
  4. Check robot footprint doesn't clip obstacles
  5. Verify the map resolution matches your needs