WrightBot Intelligent Robotic Lawnmower

Abstract

<p>The 7th Annual ION Robotic Competition is an annual competition in which top universities vie to be for the best automated lawn mower. The specifications for the WrightBot's design are dictated by the competition. In the midst of competition, the WrightBot will need to avoid both static and dynamic obstacles, while maneuvering and mowing a field. Sensors must be coordinated to efficiently analyze and avoid obstacles. Sensor design for the WrightBot includes: a dual differential global positioning system (GPS), a laser range finder, a force sensing bumper, and an electro-optic (EO) camera. All of these sensors are coordinated with the aid of a computer program. The dual differential GPS allows the WrightBot to determine its direction along with its current global position down to an accuracy of several centimeters. The laser range finder determines the WrightBot's current distance from an obstacle. To avoid static and dynamic obstacles, it is integral to measure distances. The force sensing bumpers incorporate a unique design of a microcontroller and linear potentiometers. This design determines an initial value of the reference voltage from the linear potentiometers and compares it to the current value of the linear potentiometers. This comparison along with a corresponding distance computation is performed by the microcontroller. This is useful when the laser range finder is no longer detecting an object, and the WrightBot is slowly approaching a static obstacle. The EO camera complements the laser range finder operation. With this dual system, the WrightBot is able to detect an object in the grass with the laser range finder and then compare the color spectrum of that object with a flower bed's black edge. Incorporating all of these sensors into an intelligent autonomous lawn mower will payoff during competition.</p><p>This presentation occurred at the Wright State University Campus-Wide Celebration of Research, Scholarship and Creative Activities on April 16, 2010</p>