Guided beta caseProbeginnerEncoder sign

The robot drives straight but odometry curves left

Restore odometry direction without swapping motor command polarity.

Pairs with Encoders, IMU, and odometry in Mobile Robot Reliability. Read the concept first, then diagnose it here.

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Operator report

Both wheels move forward physically, but left encoder ticks decrease.

Ubuntu 24.04, ROS 2 Jazzy, Gazebo Harmonic, RViz telemetry, differential-drive warehouse robot

System boundary

Trace only the relevant path.

wheel rotationencoder signdifferential odometry

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.

Verification

Your repair must pass more than the visible symptom.

  • Straight run yaw below 1 degree
  • Reverse run remains symmetric
  • Hidden regression behavior
  • Root cause explanation