Development and evaluation of a rope climbing sprayer robot for greenhouse environment

Abstract

The ever-increasing population has promoted inventions and innovations such as greenhouse cultivation to enhance agricultural production in terms of both quantity and quality. Despite its advantages, greenhouse cultivation provides favorable conditions for the spread of diseases and pests. While agricultural pesticides have been exploited to protect plants and crops and to combat their diseases, they are unfortunately a major source of environmental pollution. In this study, a smart sprayer rope climbing robot was designed to spray the plant row from the side in two directions (top to bottom and vice versa). Using the Mylar sheets to collect and measure droplets, the robot's performance was evaluated in terms of the effects of nozzle speed (12, 15, and 18 m/min), pressure (1.4, 2.6, and 3.6 bar), and type (flat-fan and hollow-cone nozzles) as well as leaf position (upper, middle, and lower) on such indices as numerical median diameter (NMD), volumetric median diameter (VMD), coverage percentage, uniformity index of droplet spectrum, and droplet number per unit area. In addition, comparisons were made between the proposed sprayer robot and the two back-pack and trolley sprayers in terms of their pesticide consumption and user exposure levels. Maximum and minimum pesticide consumption rates of the robot were recorded at 1.16 L and 2.6 L, respectively, when it was used to spray two rows 15 m long in a greenhouse. Finally, pesticide consumption rate by the robot was found to be by 55% and 82.9% less than those recorded for the backpack and trolley sprayers, respectively.