Have a look at this high tech approach to cutting your lawn. Sanjiv Singh from the Robotic Institute is using technology that we have seen used in many of the DARPA Grand Challenge to cut grass!

"Approach
The first approach to obstacle detection is

• color segmentation, which is the ability to distinguish obstacles based on color. We are developing a method that is robust to changes in color due to shadows and atmospheric conditions.

The second approach we are investigating is

• stereo based homography, to detect objects which lie above the ground plane.

We are also using a

• Sick^TM Laser scanner as a backup detection system, for instances where vision-based methods fail."