Weed ’em and Reap

Sally B. Patterson

Farmers may one day reap the benefit of a robot under development at the University of Illinois at Urbana-Champaign that could help them destroy more weeds with less herbicide. The device travels through a field using plant descriptions stored in its computer to identify intruder species. It has an arm that can cut the offending weeds and daub the cut stalks with herbicide. The researchers are working on coordinating these activities. They hope that, with weed killer applied precisely rather than being sprayed indiscriminately, there will be less contamination of food crops and soil.

PhD candidate Hong Young Jeon stands beside a weed-destroying robot that he helped develop at the University of Illinois. The device is powered by a solar panel and uses global positioning and a camera vision system for navigation. Courtesy of the University of Illinois.

Early renditions of the robot ran on batteries that had to be recharged every few hours. Now, agricultural engineer Lei Tian and his graduate assistants have installed a curved solar panel that not only recharges the batteries powering the machine to run at about three miles per hour, but also shades the technical equipment and protects it from the weather. Graduate student Nathanael Gingrich said that the device has operated for up to four hours on solar power alone. He added that extending operating time is the focus of his current work.

The robot’s vision system is based on two FireWire stereocameras from Videre Design of Menlo Park, Calif. A ProPak G2 global positioning system from NovaTel Inc. of Calgary, Alberta, Canada, helps to guide the wheeled device, which is roughly 5 feet long and a little more than 2 feet wide.

The developers do not yet have specific plans for commercializing the machine, but they foresee its eventually having uses far beyond weed eradication. They hope to adapt it to collect agricultural data on soil conditions and plant development as well.

Two green thumbs up!