Unit 10: Mobile Robot Motion

Two wheels can produce straight motion, arcs, and rotation. The geometry is simple enough to model and rich enough to fail in interesting ways.

Turn wheel motion into robot motion

How Two Wheels Make a Robot Turn connects left/right velocity to angular motion. Wheel Speed to Robot Motion converts rotation and units into ground velocity. Drive a Path on Paper or in Simulation turns those relationships into pose checkpoints.

The core model is differential drive, but the bigger lesson is kinematics: component motion combines into system motion.

Prediction comes first

Produce a differential-drive motion model and a path comparison.

Set a known starting pose. Predict at least one intermediate and final pose. Then compare the prediction with a simulation, supplied trace, or approved physical test.

If the result differs, locate where the error first appears instead of rewriting the entire path.

Keep the model honest

Wheel slip, compliance, unequal diameters, and geometry error can all break ideal assumptions. That is not a reason to abandon equations. It is a reason to state what the equations assume.