urgent help regarding autonomous machine

i have to make an autonomous machine which has to move in a cyclic path of rectangle(10m by 5m).
in this motion, after it has completd one cycle it has to go to a particular point outside the cyclic path......return back and follow the same path again.......

this has 2 continue for abt 10 mins.....

recommned me how i should go about it........the control circuit to be used.......this should be cheap and effective.

please help me urgently..

Do not make us guess about what you need !

Is this a class project or a contest. What is allowed and not allowed.

Does it matter how fast it moves ?

How much time do you have to develop it ?

What quanity of money do you think of as cheap ? Or better yet, what is the limit of your budget?

How close does it have to follow the path and how close does it have to be to the point ? (how sloppy can it be)

Do you want to build this with or without a microController (compuiter).

Can you use tape on the floor act as a guide ? IR markers ? Strings ?

Do you know how to program and if so in what language ?

Do you have an idea of how you would like to build it ?