Design of and Experiment with Seedling Selection System for Automatic Transplanter for Vegetable Plug Seedlings

Yongshuang Wen,Ting Yuan,Junxiong Zhang,Zhongbin Feng,Xuemei Huang,Yuzhi Tan,Leian Zhang

doi:10.3390/agronomy11102031

Abstract

In the process of vegetable plug seedling cultivation, packaging, and transportation, there may be missing, unhealthy or injured seedlings in the tray, which results in a missed planting or a low seedling survival rate after automatic transplanting. In this study, a seedling selection system with the function of seedlings identification, week seedlings elimination, and missing seedlings supplement was developed for an automatic transplanter. A plug seedling identification system based on a machine vision was used to detect vegetable plug seedlings based on the area characteristics of plug seedlings, stem leaves and plug bodies. The identification results were transmitted to a programmable logic controller (PLC), which controlled a nozzle to eliminate the unqualified seedlings from the conveyor belt lattice. When the empty conveyor belt lattice reaches the seedling throwing funnel, the rear conveyor belt lattice with the plug seedling is accelerated to ensure the continuity of seedlings supply. The adaptive fuzzy PID control algorithm was used to control the stepper motor of the conveyor belt to realize accurate seedling conveying and a seedling supplement. Using 30 days pepper plug seedlings as experimental seedlings, a comparative field experiment was carried out to evaluate the performance of the seedling selection system. The results showed that when the seedling selection system was turned on and the seedling extracting frequencies were 60, 80, and 100 plants/min, the success rates of plug seedling identification were 98.84%, 98.38%, and 96.99%, and the robust seedling rates were 98.05%, 97.78%, and 95.83%. The robust seedling rates were increased by 15.64%, 16.07%, and 13.89%, respectively, in contrast to turning off the seedling selection system.

Highlights

Vegetables are rich in nutrients, such as vitamins, minerals, and dietary fiber, which are essential for the human body
The goal of this study is to develop a seedling selection system with multiple functions of seedling identification, weak seedling elimination and missing seedling supplement for an automatic transplanter of vegetable plug seedlings [20] to improve the quality of transplanting
In the field transplanting experiment, the automatic transplanter was driven by a tractor (Luzhong, model: 604), and the frequency of taking seedlings was controlled by the throttles and the gear of the tractor

Summary

Introduction

Vegetables are rich in nutrients, such as vitamins, minerals, and dietary fiber, which are essential for the human body. They are important food sources and economic crops all around the world [1,2]. The growth status of plug seedlings is detected in real time, and the unqualified seedlings (dead, weak, diseased, and injured seedlings) are eliminated, and only robust seedlings are planted, which can improve land utilization, reduce waste of resources, and meet the requirements of precision, automatic, and intelligent agriculture [6,7]. The research on seedling selection systems has important significance for automatic transplanting and further development of the vegetable industry [8,9]

Objectives

Methods

Results

Conclusion