ROS2 Fault-Tolerant Localization

Hard System Design
#sensor-fusion#fault-tolerance#localization#gps#imu#odometry

Practice the ROS2 Fault-Tolerant Localization coding problem in System Design. Browser-based execution with automated grading — no local ROS install required.

System Design

Build a localization fusion node that combines GPS, IMU, and wheel odometry. The system must keep running even when individual sensors fail.

Input topics

  • /gps/fix (Float32) — GPS position, 1Hz, weight: highest
  • /imu/data (Float32) — IMU acceleration integral, 100Hz, weight: medium
  • /odom (Float32) — Wheel odometry position, 50Hz, weight: medium

Required output

  • /localization/position (Float32) — fused position estimate
  • /localization/status (String) — active sources, e.g. "gps+imu+odom", "imu+odom", "imu_only"

Fault tolerance rules

  • With all 3: weighted average (GPS weight=3, odom weight=2, imu weight=1)
  • GPS failed (no data for >2s): use odom+imu average
  • GPS + odom failed: use imu only (degraded)
  • All failed: publish last known position, status="dead_reckoning"

Your task

Implement LocalizationFusionNode. Starter code has the subscriptions but wrong fusion logic.

Frequently asked questions

What is the ROS2 Fault-Tolerant Localization practice problem?

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

How do I practice ROS2 Fault-Tolerant Localization 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 Fault-Tolerant Localization test?

This Hard problem focuses on sensor-fusion, fault-tolerance, localization skills used in robotics interviews and production systems.