Development of a Combined Orchard Harvesting Robot Navigation System

Zhijie Liu,Fuzeng Yang,Wei Hao,Heng Liu,Wenju Mao

doi:10.3390/rs14030675

Abstract

Our research concerned the development of an autonomous robotic navigation system for orchard harvesting with a dual master-slave mode, the autonomous navigation tractor orchard transport robot being the master followed by a navigation orchard picking robot as the slave. This addresses the problem that in single master-slave navigation mode, agricultural combined harvesting equipment cannot stop repeatedly between rows of apple trees and drive continuously when turning. According to distances obtained from a global positioning system (GNSS), ground points were used to switch the navigation mode of the transport and picking robot. A cloth simulation filter (CSF) and random sample consensus (RANSAC) algorithm was used to obtain inter-row waypoints. The GNSS point was manually selected as the turn waypoint of the master and a kinematic model was used to compute the turn waypoints of the slave. Finally, we used a pure pursuit algorithm to track these waypoints sequentially to achieve master-slave navigation and ground head master-slave command navigation. The experimental results show that the data packet loss rate was less than 1.2% when the robot communicated in the orchard row within 50 m which meets the robot orchard communication requirements. The master-slave robot can achieve repeated stops in the row using follow navigation, which meets the demands of joint orchard harvesting. The maximum, minimum, mean and standard deviation of position deviation of the master robot were 5.3 cm, 0.8 cm, 2.4 cm, and 0.9 cm, respectively. The position deviations of the slave robot were larger than those of the master robot, with maximum, minimum, mean and standard deviation of 39.7 cm, 1.1 cm, 4.1 cm, and 5.6 cm, respectively. The maximum, minimum, mean and standard deviation of the following error between the master-slave robot were 4.4 cm, 0 cm, 1.3 cm, and 1 cm respectively. Concerning the ground head turn, the command navigation method allowed continuous turning, but the lateral deviation between robots was more than 0.3 m and less than 1 m, and the heading deviation was more than 10° and less than 90°.

Highlights

Where the apple tree rows are partially interspersed with branches and leaves, a reflective film was laid on the ground near the apple trees, and the ground not covered by the film was covered by weeds
Based on the process of commercial apple harvesting, our research developed an autonomous navigation system for a combined orchard harvesting robot using two masterslave navigation methods, Wi-Fi point-to-point communication technology, target feature extraction, and pure tracking control technology, in which the transport robot is the master and the picking robot is the slave
The performance of this combined harvesting robot navigation system was verified through orchard trials

Summary

Introduction

Multi-arm picking robots [6,7], or used human-machine collaboration [8,9] to replace manual operations at individual stages of picking or transportation. Some scholars have proposed the use of combined harvesting robots to collaboratively complete picking and transportation, and their simulation results have shown that the co–robotics. 2022, 14, 675 picking and transportation, and their simulation results have shown that the co–robotics greatly reduced the labor intensity, and increased the picking efficiency by combining combining picking picking robots robots and transport robots to complete about 60% [10]. Picking is a trend in the development of fruit picking technology [3]

Methods

Results

Discussion

Conclusion