Design and Experiment of an Underactuated Broccoli-Picking Manipulator

Mature broccoli has large flower balls and thick stems. Therefore, manual broccoli picking is laborious and energy-consuming. However, the big spheroid vegetable-picking manipulator has a complex structure and poor enveloping effect and easily causes mechanical damage. Therefore, a broccoli flower b...

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Main Authors: Huimin Xu, Gaohong Yu, Chenyu Niu, Xiong Zhao, Yimiao Wang, Yijin Chen
Format: Article
Language:English
Published: MDPI AG 2023-04-01
Series:Agriculture
Subjects:
Online Access:https://www.mdpi.com/2077-0472/13/4/848
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author Huimin Xu
Gaohong Yu
Chenyu Niu
Xiong Zhao
Yimiao Wang
Yijin Chen
author_facet Huimin Xu
Gaohong Yu
Chenyu Niu
Xiong Zhao
Yimiao Wang
Yijin Chen
author_sort Huimin Xu
collection DOAJ
description Mature broccoli has large flower balls and thick stems. Therefore, manual broccoli picking is laborious and energy-consuming. However, the big spheroid vegetable-picking manipulator has a complex structure and poor enveloping effect and easily causes mechanical damage. Therefore, a broccoli flower ball-picking manipulator with a compact structure and simple control system was designed. The manipulator was smart in structure and stable in configuration when enveloped in flower balls. First, a physical damage test was carried out on broccoli according to the underactuated manipulator’s design scheme. The maximum surface pressure of the flower ball was 30 N, and the maximum cutting force of the stem was 35 N. Then, kinematic analysis was completed, and the statical model of the underactuated mechanism was established. The dimension of the underactuated mechanism for each connecting rod was determined based on the damage test results and design requirements. The sizes of each connecting rod were 50 cm, 90 cm, 50 cm, 90 cm, 50 cm, 60 cm, and 65 cm. The statical model calculated the required thrust of the underactuated mechanism as 598.66–702.88 N. Then, the manipulator was simulated to verify its reliability of the manipulator. Finally, the manipulator’s motion track, speed, and motor speed were determined in advance in the laboratory environment. One-hundred picking tests were carried out on mature broccoli with a 135–185 mm diameter. Results showed that the manipulator had an 84% success rate in picking and a 100% lossless rate. The fastest single harvest time in the test stand was 11.37 s when the speed of the robot arm was 3.4 m/s, and the speed of the stepper motor was 60 r/min.
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spelling doaj.art-57f72433c1f848f9877570e3e1a3a5802023-11-17T17:54:20ZengMDPI AGAgriculture2077-04722023-04-0113484810.3390/agriculture13040848Design and Experiment of an Underactuated Broccoli-Picking ManipulatorHuimin Xu0Gaohong Yu1Chenyu Niu2Xiong Zhao3Yimiao Wang4Yijin Chen5College of Mechanical Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, ChinaCollege of Mechanical Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, ChinaCollege of Mechanical Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, ChinaCollege of Mechanical Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, ChinaCollege of Mechanical Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, ChinaCollege of Mechanical Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, ChinaMature broccoli has large flower balls and thick stems. Therefore, manual broccoli picking is laborious and energy-consuming. However, the big spheroid vegetable-picking manipulator has a complex structure and poor enveloping effect and easily causes mechanical damage. Therefore, a broccoli flower ball-picking manipulator with a compact structure and simple control system was designed. The manipulator was smart in structure and stable in configuration when enveloped in flower balls. First, a physical damage test was carried out on broccoli according to the underactuated manipulator’s design scheme. The maximum surface pressure of the flower ball was 30 N, and the maximum cutting force of the stem was 35 N. Then, kinematic analysis was completed, and the statical model of the underactuated mechanism was established. The dimension of the underactuated mechanism for each connecting rod was determined based on the damage test results and design requirements. The sizes of each connecting rod were 50 cm, 90 cm, 50 cm, 90 cm, 50 cm, 60 cm, and 65 cm. The statical model calculated the required thrust of the underactuated mechanism as 598.66–702.88 N. Then, the manipulator was simulated to verify its reliability of the manipulator. Finally, the manipulator’s motion track, speed, and motor speed were determined in advance in the laboratory environment. One-hundred picking tests were carried out on mature broccoli with a 135–185 mm diameter. Results showed that the manipulator had an 84% success rate in picking and a 100% lossless rate. The fastest single harvest time in the test stand was 11.37 s when the speed of the robot arm was 3.4 m/s, and the speed of the stepper motor was 60 r/min.https://www.mdpi.com/2077-0472/13/4/848broccoli-pickingunderactuated mechanismmanipulatorsimulationtest
spellingShingle Huimin Xu
Gaohong Yu
Chenyu Niu
Xiong Zhao
Yimiao Wang
Yijin Chen
Design and Experiment of an Underactuated Broccoli-Picking Manipulator
Agriculture
broccoli-picking
underactuated mechanism
manipulator
simulation
test
title Design and Experiment of an Underactuated Broccoli-Picking Manipulator
title_full Design and Experiment of an Underactuated Broccoli-Picking Manipulator
title_fullStr Design and Experiment of an Underactuated Broccoli-Picking Manipulator
title_full_unstemmed Design and Experiment of an Underactuated Broccoli-Picking Manipulator
title_short Design and Experiment of an Underactuated Broccoli-Picking Manipulator
title_sort design and experiment of an underactuated broccoli picking manipulator
topic broccoli-picking
underactuated mechanism
manipulator
simulation
test
url https://www.mdpi.com/2077-0472/13/4/848
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AT xiongzhao designandexperimentofanunderactuatedbroccolipickingmanipulator
AT yimiaowang designandexperimentofanunderactuatedbroccolipickingmanipulator
AT yijinchen designandexperimentofanunderactuatedbroccolipickingmanipulator