Development and evaluation of an intelligent multivariable spraying robot for orchards and nurseries

Pesticide spraying is one of the important measures to protect crops from pests and diseases in agricultural environment. In this paper, a precision multivariable spraying robot with swing fan structure is designed. The robot has the characteristics of variable flow rate, variable air volume, adjustable droplet diameter and adjustable spray direction. The function of changing spray direction is realized by crank rocker mechanism, and its swing angle reaches up to 30 degrees. degrees . Target plants are extracted from the orchard environment point cloud by an improved DBSCAN(Density Based Spatial Clustering of Applications with Noise) algorithm. A multivariable spray model was proposed for controlling each spray unit and air-assisted unit according to the extracted target plant information. Further more, the robot can change the droplet diameter by adjusting the rotating speed of the centrifugal nozzle. The experiment results show that the multivariable spraying robot reduces the spray dosage by 83% compared with conventional spray and the spray effect is improved.