Pricing
00
Guided beta caseProbeginnerCommand interface

The controller loads but cannot activate

Expose the required interface without weakening controller validation.

Pairs with ros2_control interfaces in Hardware Integration & CANopen. Read the concept first, then diagnose it here.

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Operator report

`diff_drive_controller` is loaded but activation fails with missing `left_wheel_joint/velocity`.

Ubuntu 24.04, ROS 2 Jazzy, SocketCAN vcan, CANopen drive simulator, ros2_control

01

System boundary

Trace only the relevant path.

3 nodes
  1. 01hardware interface export→
  2. 02controller resource claim→
  3. 03wheel commandOUT
02

How this lab works

You diagnose it. No command list.

Open the repair workspace and gather your own evidence in a real terminal. No diagnostic commands are handed to you - finding the fault is the exercise. Stuck? Progressive hints unlock inside the workspace.

03

Verification

Pass more than the visible symptom.

4 checks
  • Controller activates
  • Velocity interfaces are claimed
  • Hidden regression behavior
  • Root cause explanation