Physical and mechanical properties of hydroponic lettuce for automatic harvesting  

作　　者：Wenqi Wang Yidong Ma Longsheng Fu Yongjie Cui Yaqoob Majeed 

机构地区：[1]College of Mechanical and Electronic Engineering,Northwest A&F University,Yangling,Shaanxi 712100,China [2]Key Laboratory of Agricultural Internet of Things,Ministry of Agriculture and Rural Affairs,Yangling 712100,China [3]Shaanxi Key Laboratory of Agricultural Information Perception and Intelligent Service,Yangling 712100,China [4]College of Agricultural Equipment Engineering,Henan University of Science and Technology,Luoyang 471003,China [5]Centre for Precision and Automated Agricultural Systems,Washington State University,Prosser,WA 99350,USA

出　　处：《Information Processing in Agriculture》2021年第4期550-559,共10页农业信息处理（英文）

基　　金：supported by the Key Research and Development Program in Shaanxi Province of China[grant number 2018TSCXL-NY-05-04,2019ZDLNY02-04].

摘　　要：To design an automatic harvesting machine for hydroponic lettuce(Lactuca sativa L.),physical and mechanical properties of hydroponic lettuce were investigated and analyzed.Moisture content of stem,root and leaf,geometric characteristics,pulling force,and root cutting force were studied for harvesting hydroponic lettuce.The pulling force was examined by a tensile experiment,while the root cutting force was investigated by a shear experiment on the electronic universal testing machine.The moisture content of hydroponic lettuce was obtained by direct drying.Experiment data were processed using regression analysis and mathematical statistics method.A regression equation and the law of numerical distribution were obtained.The results showed that the geometric size of different hydroponic lettuce had little difference,and the distribution of physical parameters was concentrated.Moisture content was found statistically similar in stem and root(around 91%),while the highest moisture content was found in the leaf of 95.73%.The root cutting force decrease with the increase of cutting speed and decrease with the cutting position move downward.The minimum average root cutting force in the experiment was 1.41 N.The average pulling force was 13 N.This study provides adequate theoretical support for the design of the automatic harvesting machine of hydroponic lettuce.

关 键 词：Greenhouse vegetable HARVESTER Variance analysis Response surface 

分 类 号：S225[农业科学—农业机械化工程]