SUGISAKAMASANORI

Journal of Robotics, Networking and Artificial Life
Vol. 9(1); June (2022), pp. 20–24
ISSN (Online): 2352-6386; ISSN (Print): 2405-9021
https://alife-robotics.org/jrnal.html

Research Article

System Design of Daylily Picking Robot
Jichao Zhao, Fengzhi Dai, Tianyi Zhang

College of Electronic Information and Automation, Tianjin University of Science and Technology, Tianjin, China

ARTIC LE INFO
Article History
Received 20 November 2020
Accepted 10 August 2021

Keywords
Picking Robot
Daylily
Agricultural
Robot DesignABS TRACT
Agricultural picking is a key part of agricultural production activities. In recent years, people
are committed to improving picking efficiency and freeing labor, and agricultural picking robots
have emerged and are widely used. Daylily, as a crop for daily consumption, can significantly
reduce serum cholesterol and has extremely high nutritional value. However, Daylily picking
time and picking standards are relatively strict, long-term picking daylily will also damage thehealth of the work. The daylily picking robot designed in this paper can effectively solve thecurrent picking problems, such as: improving picking efficiency, standardizing picking, andreducing physical hazards to laborers© 2022 The Author. Published by Sugisaka Masanori at ALife Robotics Corporation Ltd
This is an open access article distributed under the CC BY-NC 4.0 license(http://creativecommons.org/licenses/by-nc/4.0/).

automatically pick daylily have become an important andurgent need.
Regarding the research of automated daylily picking, in2012, Shanxi Province, China, developed a riding style
daylily picker. The production efficiency of this picking
device is 1.45 times higher than the traditional production
method, and the production cost is reduced by 25.2%. Thiseffectively solves the problem that daylily pickers are
soaked by dew and harms their bodies, significantly
improves the working conditions of daylily pickers,
reduces labor intensity, and has obvious economic andsocial benefits.
This paper designs a daylily picking robot 1. The robot
mainly completes four tasks. 1) Using the camera to collectthe image, then using the image processing algorithm
based on machine vision deep learning in the device tolearn the characteristics of daylilies independently. such ascolor, contour shape, size, etc. 2) According to the above
characteristics to determine whether the object being
photographed is the pickable daylily. 3) Through the

1. Introduction
Daylily, also known as Golden Needle, has been cultivatedin China since ancient times. The flower of daylily has
high ornamental value, and its buds are picked and dried
to become vegetables with high nutritional value. Daylilies
usually grow buds at dusk each summer, bloom the nextmorning from 5-8 am and wither around noon.
According to the physiological characteristics of daylily,
its harvesting season is usually from June to August everyyear, which lasts more than 40 days. During that time, thepicking staff must pick at 5-8 am every day to ensure thebest quality of daylily, which is shown in Fig.1. Otherwise,
nutrients will be lost after blooming, and both the quality
and the price will be low. The harsh picking conditions
have greatly affected the picking efficiency of daylily, andlong-term picking activities will cause certain harm to thehuman body. Therefore, agricultural robots that
Corresponding author’s E-mail: daifz@tust.edu.cn, www.tust.edu.cn20

how the driving mechanism moves. The power system isresponsible for powering the entire robot.

camera to determine the location of the pickable daylily,
after the coordinate conversion algorithm to determine thehorizontal and vertical position of the daylily2, 3. 4) Finallyusing the parallel robotic arm with cutting and grabbing
functions to pick the daylily and put it into the designatedposition4.

2.1. Vision System
In this design, the vision system is an important part
responsible for obtaining picture information and feedingit back to the robot arm, and its recognition accuracy andspeed have a great impact on the picking speed of the robot.
The vision system needs to meet the following
requirements. 1) Can effectively identify the maturity ofdaylily, selective picking, to ensure the quality of picked
daylily. 2) Identify the position coordinates of daylily inspace, including horizontal and vertical coordinates andthe distance between the camera module and daylily, assist
the picking of the manipulator. 3) It can judge whether therobot is still in the field by identifying the environment,
and assist the robot in walking to a certain extent.
Therefore, we choose the RGB-D binocular camera withdepth function as our visual system 5, which is shown inFig.3.

Fig.1. Pick daylily

2. Robot Design

Fig.3. The main global currents

The agricultural robot designed in this paper includes avision system, picking structure, mobile structure,microcontroller, and power system. The functional
structure of the robot is shown in Fig.2.

The camera module has the following characteristics:• Depth range: 0.6-8m• Depth map resolution: 1280*1024 max• Depth filed angle: 58.4*45.5cm• Time delay: 30-45ms• RGB: 1080P• Connection type: USB

Fig.2. The functional structure of the robot

The functions of each part of this robot are described asfollows. Through the vision system to identify the maturityof daylilies and the location information on the branches,the picking structure uses the recognized image
information to separate the ripe daylilies from the branches.
The mobile structure is responsible for the movement ofthe robot. The microcontroller is used to process theinformation sent back by the recognition module, and issue
the instruction whether the picking structure picks, and2.2. Picking Structure
In the picking part, we use an under-actuated flexible
manipulator instead of the common rigid manipulator tocomplete the Daylily picking work to ensure no secondary
damage to the crop. When picking, the manipulator relieson the cylinder to provide pressure to drive the fingers toclose. This manipulator adopts a pneumatic drive.
Compared with an electric drive, it can further adjust the21gripping force of the manipulator by adjusting thepneumatic pressure to protect the daylily from being
damaged 6. The manipulator is shown in Fig.4.

We use a crawler drive. The contact area between thecrawler and the ground is large, the conflict force grip isstrong, and it is not easy to sink. The crawler type can walkon any messy terrain without any influence, and can also
walk normally in any muddy and soft ground. Whether itis the rainy southern part of China or the monotonous north,whether it is a mountain or a plain, whether it is sandy or
muddy, the crawler drive can make the robot seem to walkon flat ground.

2.4. Microcontroller
The microcontroller adopts the design scheme of dual
controller STM32-Raspberry Pi. The two controllers areshown in Fig.6 and Fig.7 respectively.
Fig.4. The manipulator

2.3. Mobile Structure
The movement of the picking robot should be adapted to
the growing environment of Daylily. According to thegrowing environment of daylily, we adopt the crawler
drive instead of the conventional wheel drive.
As is shown in Fig.5, the planting base of daylily issandy land, which has a high requirement for the tire of thepicking robot. If the wheel drive, it is easy for the tire toslip. And if it is cloudy and rainy, the ground will become
muddy, and wheeled robots will be unable to move at all.

Fig.6. STM32 main global currents

Fig.7. Raspberry Pi main global currents

STM32 microcontroller is general-purpose embedded
microcontrollers based on the ARM Cortex-M3 core. It is
the first choice for embedded control chips. This
microcontroller has the characteristics of strong real-time,
low power consumption, high integration, and a richperipheral library, which is convenient for development.
Here we use it to connect the mobile structure that drives
the robot and the picking structure.
Raspberry PI runs a customized version of Linuxinternally, which allows for a rich set of processing
software to be installed within the system for different

Fig.5. Daylily planting base22

robot can effectively improve people's labor production
efficiency, and more importantly, avoid the harm caused
to the human body by the daylily picking.

processing functions. It can process the captured video andimages can be processed multiple times and arbitrarilymodified.
We use the Raspberry PI to connect to the vision system
to process video information.

References
1. Zhao JC, Dai FZ, et al. Device Design Based on
TDS Water Quality Detection, International
Conference on Artificial Life and Robotics, Oita,
Japan, 2020, 1: P620-623.
2. J. B. Han, K. M. Yang, et al. A Modeling andSimulation based on the Multi body Dynamics for
an Autonomous Agricultural Robot. 7thInternational
Conference
onControl,Mechatronics and Automation, Delft, Netherlands,
2019, pp. 137-143.
3. U. Rao. Design of automatic cottonpicking robot
with Machine vision using Image Processing
algorithms. International Conference on Control,Automation, Robotics and Embedded Systems,Jabalpur, 2013, pp. 1-5.
4. Y. Yu, K. Zhang, et al. Real-Time VisualLocalization of the Picking Points for a RidgePlanting Strawberry Harvesting Robot. IEEEAccess, 2020, 8: pp. 116556-116568.
5. Z. Xu, R. Jia, Y. Liu, et al. Fast Method ofDetecting Tomatoes in a Complex Scene for
Picking Robots. IEEE Access, 2020, 8: pp. 5528955299.
6. G. Bao, P. Yao, et al. Flexible pneumatic endeffector for agricultural robot: Design &experiment. IEEE International Conference onRobotics and Biomimetics, Zhuhai, 2015, pp. 21752180.
7. A. J. Scarfe, R. C. Flemmer, et al. Development of
an autonomous kiwifruit picking robot. 4thInternational Conference on Autonomous Robots
and Agents, Wellington, 2009, pp. 380-384.

2.5. Power System
The power system is the power source of the whole system
and is responsible for providing power for STM32,
Raspberry PI, vision system, etc. The L78 series of threeterminal positive regulators (Fig.8) is available in TO-220,
TO-220FP, D²PAK, and DPAK packages and several
fixed output voltages, making it useful in a wide range ofapplications 7.

Fig.8. The L78 serial package

Different systems require different voltages, thisrequires the power system to be able to output different
voltages stably., this requires the power system to be able
to output different voltages stably. Therefore, L78 meets
our power demand, so the L78 series is adopted as ourpower chip.

Authors Introduction
Mr. Jichao Zhao

3. Conclusion
In this paper, we designed an agricultural picking robot of
daylily according to its physiological characteristics,
growth environment，and growth traits. The robot obtains
the spatial coordinates of daylily through image
recognition, then analyzes its data information and passes
it to the controller to drive the robot arm for picking. The23

He is a third-year mastercandidateinTianjin
University of Science andTechnology. His research isabout multi-agent system,
controlsystem
andreinforcement learning

Dr. Fengzhi Dai

He eceived an M.E. andDoctor of Engineering (PhD)from the Beijing Institute ofTechnology, China in 1998
and Oita University, Japan in
2004 respectively. His main
research interests are artificial
intelligence,patternrecognition and robotics. Heworked in National Institute ofTechnology, Matsue College, Japan from 2003 to 2009.
Since October 2009, he has been the staff in Tianjin
University of Science and Technology, China, where heis currently an associate Professor of the College ofElectronic Information and Automation.
Ms. Tianyi Zhang

She is a second-year mastercandidate in Tianjin Universityof Science and Technology. Her
major is image processing,machine learn and deeplearning.

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