If you don't know what a control systems is, you probably won't be able to do a project on one until you do more research. What a control system tries to do is use feedback to translate an input into a desired output state, and cause the output to approach this desired state as fast as possible with minimum overshoot.
Probably doesnt even matter...since they probably will never come back seeing as how they left their e-mail. Sounds like someone who just wants a homework project which is a bit strange if they are in a controls class and don't know what a control systems is. So that could mean that they are just curious about control systems, in which case they'd come back to check up on the thread soon.