Robot Lawn Mower At UF Designed To Change Suburban Landscape

A robot lawn mower called LawnNibbler, developed at the University of Florida's Machine Intelligence Laboratory, can cut your grass intelligently -- avoiding dogs, kids, trees and birdbaths -- while you're out on the golf course or taking the kids to soccer practice.

"The LawnNibbler can provide a substitute for the majority of the work a person does caring for a lawn," said Kevin Hakala, the graduate student who designed and built LawnNibbler for his engineering master's thesis, written under the guidance of Professor Keith L. Doty, laboratory director. "It will trim the grass in a defined area while avoiding obstacles such as trees, children, toys or pets. It uses two smart systems: one to tell it where it is and another to tell it what to avoid."

Hakala said LawnNibbler promises to be the first low-cost and efficient robot lawn mower. It uses a radio wire buried at the perimeter of its work area and a navigational beacon system using sonar and infrared emitters and detectors to tell it where it is in its environment.

"LawnNibbler uses signals to treat the buried wire as an obstacle that it cannot cross," Hakala said. "It moves straight ahead until its sonar senses a beacon in its work environment or an obstacle."

Beacon or obstacle identified, LawnNibbler makes the appropriate turns and continues. Additionally, LawnNibbler can keep track of where it has already cut. LawnNibbler's navigation system scans its surroundings with sonar pulses. If a beacon in the yard "hears" the sonar, the beacon replies with an infrared light. The infrared light also provides LawnNibbler with its obstacle avoidance mechanism.

Just 24 inches high, 23 3/4 inches long, 12 3/4 inches wide and weighing 35 pounds, LawnNibbler uses a weed trimmer-like nylon cord that cuts a 6-inch swath.

Hakala said that the mower, driven by a rechar