Design and experiment of local grapevine trunk targeted precision sprayer

Abstract: Precision pesticide technology is developing fast, and gradually applied to agriculture and forestry production. Precision pesticide will become the standard mode of application in the future for fruit trees. Cutworm is one of the serious harm to the growth of grape pests, "Barrier zone" is the effective control method of cutworm prevention, this method is forming a barrier of not less than 15 cm for medicine close to the soil in grape tree sprayed with pyrethroids, hinder from the root up cutworm crown eating grape's buds and shoots, such method not only reduces the cost, but also reduce the impact on other non-target insects. This paper propose a kind of intelligent target circular precision pesticide method, and designed the mechanism and control system, in order to realize the automatic targeting, and then precisely spraying a "Barrier zone".The work of circular target pesticide application process is the laser sighting, target determination, localization of fine-tuning and spraying around the grape tree. Nozzle motion mechanism is composed of two parts, translation mechanism and a circular rail sliding mechanism. The translation mechanism has 2 degrees of freedom moving axially perpendicular to each other; circular rail sliding has two semicircular orbits which linked by a hinge. When the sprayer working, translation mechanism adjusts the position make grape trunk in the center, then forming a circular orbit with semicircular orbit. The nozzle rotates along the circular orbit around the trunk of grape in the rolling platform, so the nozzles can spray pesticide around grape trunk. The control system includes 2 parts, which are target detection module and motion control module. Laser scanning and visual identification information fusion method is using to detect targets. After the laser range finder has finished a complete two-dimensional scan, the target size and position information can be obtained by the target identification algorithm. CCD camera is used to capture target images, then OpenCV was used to detect the contour of target image acquisition to the spraying equipment to judge the object in front is curved or straight trunk of grape stakes, if it is determined that the bending grape trunk is fine and perform precision pesticide, if it is determined that the straight stakes, then sends signals to let the trailer to move on. In the experiment, 30mm, 40mm, 50mm three different sizes of straight type, slanting type and twisted trunk are included. Two environment situation: wind and no wind were considered in spraying experiment design. Test shows that the application effect of two kinds of application methods of target diameter and shape target slightly affected, but the impact is not marked. Target circular precision pesticide method got the average drug coverage rate as 96.87% on target, and the drug' utilization ratio as 75.61% in wind environment. When in wind environment, the average drug coverage rate is 89.71%, and the drug' utilization ratio was 67.61%. The device with the drug' utilization ratio is not only much higher than the traditional vehicle strip application method is also higher than that of multi nozzle proposed by Washington State University to target pesticide application methods. Circular on target was not only can reduce the cost but also reduce the environmental pollution.