The Lawn Ranger was an early robotic lawn mower that was featured as a build-it-yourself project in Radio Electronics magazine. It was presented as a multi-part series of articles by Ramond Rafaels titled Build the Lawn Ranger. The articles ran in the June through September 1990 issues.
The original design was created by a Technical Solutions, Inc. of Damascus, MD. They sold kits, parts, and a demo videotape. The full kit sold for $757.
The Lawn Ranger had much in common with today's robotic mowers. It used two motors to drive the wheels and two motors for cutting. A set of bumpers were employed as a safety shut off. The electronics were divided by function among four PC boards. Control was handled by a Z80 microprocessor.
Everything was mounted an aluminum frame and protected by a molded ABS plastic top.
Navigation was accomplished by a row of 15 infra-red sensors mounted in the front of the unit. These sensors detected the grass height to determine what parts of the lawn had been mowed. The user would first manually mow around the perimeter of the yard and around any obstacles. The mower would then use its infra-red sensors to detect and follow the edge of the previously mowed areas.