Autonomous lawnmower event is GPS cutting edge

GPS World, July, 2004

A novel competition among university engineering students to build a GPS-guided lawnmower that could cut 150 square meters of grass without human intervention didn't turn out to be quite the Tom Sawyer moment that some had imagined.

Sponsored by the Institute of Navigation (ION) and held during the group's annual meeting in Dayton, Ohio, the Autonomous Lawn Mower Competition drew teams from Illinois Institute of Technology, Miami University--Ohio, and Ohio University.

The event was somewhat reminiscent of the recent Grand Challenge by the Defense Advanced Research Projects Administration (DARPA) in which 15 teams attempted to navigate autonomous vehicles across the southern California desert ((See Global View, April 2004, GPS World). None finished the course to gain the $1 million prize.

Similarly, the lawnmowing event's premiere--co-hosted by ION's Dayton Section--left unshorn most of the greensward at the Rotary Park in Beavercreek, Ohio. But that appears to have only inspired greater interest in the 2005 competition, which has already drawn interest from several additional schools, according to Mikel Miller, a senior electronics engineer for the Air Force Research Laboratory's Sensors Directorate and the ION's chair for the event.

"This was a great competition for students to gain an appreciation for the difficulty associated with autonomous vehicle research and development," said. Miller. "Mowing a yard accurately and precisely is an extremely difficult and challenging systems problem. Centimeter-level accuracy and precision control are required for straight lines and smooth turns. Unfortunately, not much grass was cut this year; however, we are confident that all the teams learned critical lessons that will lead to much greater success next year."

In this year's event, the teams were given world coordinates for the fields' corners in order to incorporate GPS into their robots' navigational schemes. Armed with this information, the lawnmowers were to mow an assigned area without going outside a threemeter safety zone. The team that cut the field of grass in the shortest amount of time was crowned the winner. Any uncut grass after a run was converted to a time penalty, as was any time spent outside the playing field but within the safety zone.

Each team participating in this exciting event had a unique design, and all teams were able to cut some portion of the playing field. Ohio University was awarded first place and a check for $2,500, edging out second place Miami University, who was able to cut a larger portion of grass but at a much slower pace and outside the designated lawn area. Miami received $1,500 for their efforts. Illinois Institute of Technology finished in third place and was awarded $1,000.

Teams have a year to prepare for the next competition scheduled for June 2005, when the course will be slightly more difficult as a result of added obstacles on the playing field, says Miller. Each subsequent year will bring additional complications to the competition with the end goal of developing mowers with the ability to autonomously navigate any lawn safely.

For more information on the competition, visit the ION website at www.ion.org or email Mikel Miller at Mikel.Miller@wpafb.af.mil.