Here's a few ideas that were done previously by some senior undergrad students on robotics. These topics were more advanced than what undergrad courses had to offer, but you can simplify them.
1. A robot (on a electric wheelchair chasis), with a robotic arm (I think it was a magnet), that picked up pop cans and moved them to another location. Now this project had fairly sophisticated control from electronics side, but even a more complex image processing that would identify the pop cans in robot's environment.
2. A coordination of robots (distributed or centralized) in a hazardous environment. (Something like a mineshaft, where robots would carry the ore to the surface). This is more of an AI project, but it involves different position and obstacle sensing techniques.
I am not sure if this helps....Maybe somebody else can suggest better projects...