Optimal Path Planning Program for Autonomous Speed Sprayer in Orchard Using Order-Picking Algorithm

This study was conducted to develop a software program which computes optimal path for autonomous navigation in orchard, especially for speed sprayer. Possibilities of autonomous navigation in orchard were shown by other researches which have minimized distance error between planned path and performed path. But, research of planning an optimal path for speed sprayer in orchard is hardly founded. In this study, a digital map and a database for orchard which contains GPS coordinate information (coordinates of trees and boundary of orchard) and entity information (heights and widths of trees, radius of main stem of trees, disease of trees) was designed. An orderpicking algorithm which has been used for management of warehouse was used to calculate optimum path based on the digital map. Database for digital map was created by using Microsoft Access and graphic interface for database was made by using Microsoft Visual C++ 6.0. It was possible to search and display information about boundary of an orchard, locations of trees, daily plan for scattering chemicals and plan optimal path on different orchard based on digital map, on each circumstance (starting speed sprayer in different location, scattering chemicals for only selected trees). In efficiency, developed path from this program was compared to conventional path by calculating travel distance on several occasions. Optimum path for rectangular-shaped orchards traveling whole trees showed the same working path as conventional method. But, for irregular-shaped orchards, the program developed in 5% shorter path than conventional method. 10 T. S. Park , S. J. Park , K. Y. Hwang , S. I. Cho When optimum path was created to travel randomly selected trees, the program developed in 11.5% shorter path. The program always developed shorter path on any shape of orchard. Order-picking algorithm based optimal path developing program in orchard showed efficiency of traveling distance and expected to present path which lead working time and cost efficiently in orchard.