Modified Design of a Precision Planter For a Robotic Assistant Farmer

Abstract 
Modified design of a planter to be attached to a mobile robot, was the main objective of 
this project. This research project was part of a larger project, called “Developing robotics 
assisted technology for farming”.
The main motivation for this research project is the fact that mobile robot, is an electric 
powered vehicle with limited power and pulling force. Thus, a customized planter with a 
customized connection mechanism should be designed. Besides, it should require less draft force 
compared to existing planters so that it can be pulled by the mobile robot. The developed planter 
should have the same efficiency as the existing planters in seeding. 
To find the forces between soil engagement tool (disc coulter) and soil, experiments were 
designed and performed in the Linear Soil Bin at University of Saskatchewan. Disc and tilt angle 
of a disc coulter was changed and draft, vertical and side forces applied to it were measured to 
find the disc and tilt angle combinations that results in minimum draft force. Experiments 
showed that 7° disc angle and 25° tilt angle provides the least draft force compared to other disc 
angle and tilt angle combinations. Then, using the knowledge obtained from literature and the 
soil bin experiments, a planter was designed conceptually and in detail, based on the existing 
CNH planter. For further analyses computer modeling was performed. The whole planter was 
modeled in 3D, using SolidWorks. Stress analysis was performed in ANSYS Workbench to 
calculate safety factor of the designed parts. Two prototypes were fabricated and were attached 
to the mobile robot for field tests. Tests were performed in indoor settings to measure the total 
draft force required to pull developed planters. Draft force was very close to the value that was 
calculated in design stage. Results showed that an average of 460 N pulling force is required to 

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pull one row planter for 50 mm depth of cut, which can be compared to n existing CNH corn 
planter that requires a pulling force of between 900 N to 1300 N. Seed drop accuracy and 
function of the developed planters in opening and closing a packed soil in presence of residue, 
were also observed in outdoor tests.

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Acknowledgment 
I want to thank my supervisor Prof. Reza Fotouhi who guided me through the work and 
supported me both in my research and my personal life. I am also grateful for the help of my 
advisory committee for excellence of this research. I want to appreciate the time and financial 
support that Mr. Jim Henry and CNH industries dedicated to this research.
I also want to thank my colleagues, Mr. Ahad Armin, Mr. Carlos Mondragon, Mr. 
Ashkan Oghabi and Mr. Farzam Ayatizadeh, who helped me with my experiments and analysis. 
Also the help of department assistants, Mr. Douglas Bitner and Mr. Louis Ruth are greatly 
appreciated for helping me to setup the experiment setups and tests.

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Dedication 
This thesis is dedicated to my mom and dad, 
who sacrificed their dreams to make mines come true. 
& 
My lovely sister, Neda, and my best friends, Farnoosh and Sina, 
which being away from them was the hardest thing I have ever experienced. 

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