Virtual fences to herd Wi-Fi cattle

Virtual, moving fences controlled from a laptop could one day herd cattle to fresh fields for grazing, a roboticist told the MobiSys 2004 conference in Boston, Massachusetts, on Sunday.

A farmer would control multiple herds from a single server at home as if they were playing a video game, said Zack Butler, of Dartmouth College in Hanover, New Hampshire.

Although static virtual fences already keep dogs inside yards in affluent US neighbourhoods, no-one has attempted a moving virtual fence before, nor attempted to apply the idea to large herds of animals. “Basically we download the fences to the cows,” says Butler. “We say: ‘Today stay here, tomorrow go somewhere else.”

Butler and his colleagues have written software that transmits the chosen GPS co-ordinates of a virtual fence to head-collars worn by the cows in the field.

When a cow strays towards these co-ordinates, software running on the collar triggers a stimulus chosen to scare the cow away, such as a sound or a small electric shock - this is the “virtual” fence. The software also “herds” the cows when the position of the virtual fence is moved.

PDA and GPS

Each collar is equipped with a Wi-Fi networking card, a Zaurus PDA, an eTrex GPS unit and a loudspeaker, all of which are off-the-shelf components. The server and the collars communicate using the 802.11B Wi-Fi standard, using a Wi-Fi base station in the field.

Source: News Scientist