如何让我的机器人沿着黑胶带在矩形路径上移动?

I am working on a robot, it's part of the summer robotics workshop in our college. We are using C-STAMP micro controllers by A-WIT. I was able to make it move, turn left, turn right, move backward. I have even managed to make it go along the black tape using a contrast sensor. I am working on a robot, it's part of the summe