Design and test of automatic toward-target sprayer used in orchard

Abstract

In order to meet the requirements of large-scale spraying operations in the orchards which covers an extensive area, an Automatic Toward-target Sprayer was designed. The sprayer uses two infrared sensors, which are respectively mounted on both sides of the machine, to detect fruit trees. The control system detects the speed of the tractor in real time by processing the pulse signal of a Hall sensor. If the target is detected, the location and speed, which can be used to calculate the position and width of spraying, will be stored in the memory. After the tractor traveling a certain distance, the spraying valves are triggered. If there is a tree, the sprayer will start spraying, if there is a gap, the sprayer will stop spraying. The spraying width can be changed by setting control parameters to accommodate different size trees. Actual test application shows that while the tractor is moving at a low speed which is not more than 1.5m/s, and the target is within the detection range of the sensor(<=70cm), the sprayer can accurately detect trees. If the target is detected, the sprayer will spray pesticides on target within a set width.