Lectures #4 and #5 looked at basic kinematic models of robots.
Two sets of notes are available. Those from the textbook authors:
The lecture covered material from Chapter 3 of the textbook. You should read this if you have the textbook.
Note that the textbook and the notes from the textbook (which, thanks to the magic of Powerpoint I can't edit) seem to have an error: where they refer to the diameter r of the wheel in the derivation of the motion of the differential drive robot, I think they mean the radius (certainly later in the chapter they use r for radius.