AUTONOMOUS Robotic Vehicle for Greenhouse Spraying

Abstract

A six-wheel differential steering vehicle was designed and built to act as a greenhousesprayer. Power was transmitted from the DC motors to all wheels through a chain and sprocketsystem. A fuzzy logic-based proportional-derivative controller was developed and tested to controlthe left and right motors, which navigate the vehicle through the aisle way using range informationprovided by ultrasonic sensors. The vehicle was tested on sand and concrete surfaces using twomodes of operation. In the first mode (self-contained mode), the base vehicle contained the wholespraying system, i.e., sprayer tank, boom, pump, etc., while in the second mode (trailer mode) thespraying system was towed by the base vehicle along the aisle.<br><br>Results show that the self-contained mode performed better than the trailer mode on both sand andconcrete. There was an average RMS path error less than 1 for an aisle width of 24, and aninstantaneous average error less than 0.25. The robotic sprayer successfully navigated 18, 20 and24 aisle widths.