DESIGN AND EXPERIMENTAL STUDY OF A SMART TREE WHITEWASH DEVICE BASED ON HUMAN–COMPUTER INTERACTION

Abstract

Tree whitewash has the functions of parasite prevention and cold protection and is therefore commonly used in the maintenance and management of trees. At present, tree whitewash mainly relies on manual operation, which has the problems of low efficiency, poor quality, and uneven distribution of the whitewash agent. To address this issue, this study developed a smart tree whitewash device based on human–computer interaction. The device was controlled mainly by a programmable logic controller (PLC). Once the trunk information collected by sensors was received by the PLC, it would control the up and down motions of the ball screw to manipulate the mechanical arm for whitewash. In addition, a Mitsubishi GT12 touch screen was adopted to facilitate system operation. Subsequently, a whitewash experiment was performed on poplar trunks with lengths of 10–35 cm using three different whitewash devices, i.e., a backpack sprayer, a semi-automatic tree sprayer, and the proposed smart tree whitewash device; the efficiency and the amount of whitewash agents used were compared. The results suggested that as the tree diameter at breast height increased, the amount of required whitewash agent elevated accordingly. In this case, the time required by the backpack sprayer and the semiautomatic tree sprayer to complete the job both increased, whereas that required by the smart tree whitewash device remained almost identical. In terms of work efficiency, the time required by the smart whitewash device to whitewash a tree was 109.89 s, which was approximately 1/2 of the time required by the backpack sprayer or 2/3 of that required by the semiautomatic tree spraying device. Meanwhile, the amount of whitewash agent required by the smart whitewash device to whitewash a tree was 140.23 g, which was approximately 0.46 of the amount required by the backpack sprayer or 0.74 of that required by the semiautomatic tree spraying device. Therefore, it was concluded that the proposed smart tree whitewash device could not only improve the work efficiency of tree whitewash but also greatly reduce the amount of whitewash agent required, thereby decreasing the cost and minimising environmental pollution. This study provides theoretical guidance and technical support for future research on smart tree whitewash devices.