Differential Drive Kinematics

Source: ros2-copilot-skills differential drive model skill

Why This Matters

Diff-drive robots look mechanically simple, but their control and odometry logic only make sense when the underlying kinematic assumptions are explicit. Many navigation problems trace back to misunderstanding that model.

Distilled Takeaways

• Diff-drive motion comes from the relationship between left and right wheel motion.
• Wheel radius, track width, and slip assumptions shape both control and odometry.
• A clean kinematic model is prerequisite knowledge for tuning higher-level navigation.
• Real robots depart from the ideal model, which is why calibration matters.

Practical Guidance

• Use the ideal kinematic model as a baseline, then validate it against the real robot.
• Recheck track width and wheel radius assumptions after hardware changes.
• Treat persistent turn or arc errors as model-calibration issues early.
• Keep the kinematic model in mind when interpreting cmd_vel and odometry behavior.

Corroborating References

• REP 103 standard units and conventions
• ros2_control diff drive controller docs

When to Read the Original Source

Go to the original skill when you want the diff-drive math intuition and the practical relationship between ideal kinematics and real robot behavior.