ROS2 The Graceful Degrader

Hard Safety-Critical
#safety-critical#fault-tolerance#state-machine#sensors#degradation

Practice the ROS2 The Graceful Degrader coding problem in Safety-Critical. Browser-based execution with automated grading — no local ROS install required.

System Design — Safety-Critical

Build a system health monitor for an autonomous delivery robot. When sensors fail, the robot must degrade gracefully rather than crash or behave unsafely.

Degradation rules

Failed sensor Required behavior
GPS only Continue with odometry + map matching (50% speed)
Camera only Continue with LiDAR only, 50% speed
LiDAR Stop immediately, wait for recovery
WiFi Complete current delivery, return to base, no new tasks
GPS + Camera Continue at 30% speed (degraded but safe)

Required topics

  • Subscribe: /sensors/gps_ok, /sensors/camera_ok, /sensors/lidar_ok, /sensors/wifi_ok (Bool)
  • Publish: /robot/mode (String) — one of: full, gps_degraded, camera_degraded, critical_degraded, stopped, return_to_base
  • Publish: /robot/max_speed (Float32) — speed cap for current mode

Your task

Implement the SystemHealthMonitor node. Starter code has empty callbacks and wrong mode logic.

Frequently asked questions

What is the ROS2 The Graceful Degrader practice problem?

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

How do I practice ROS2 The Graceful Degrader 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 The Graceful Degrader test?

This Hard problem focuses on safety-critical, fault-tolerance, state-machine skills used in robotics interviews and production systems.