Modified Design of a Precision Planter For a Robotic Assistant Farmer

3-2- Conceptual design 
The conceptual design phase started with the selection of the parts that were preferred to 
be used in the planter. Taking a look at an existing planter, figure 3-2, we can see different parts 
and components. 
CNH-Saskatoon partially supported this research, and they donated two planters to us to 
be used for prototype. Some of parts of this planter were used, and other parts were modified for 
our new planter. Coupled seed hopper and precision seed metering system is one of the parts 
that was used without any change from the donated planter. No research or analyses were 
performed on this part; because design of the seed hopper and singulation system was not part of 
the objectives of this research. So the seed hopper and its frame were kept without any change 
and they were added to new designed parts. 

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Figure 3- 2- Existing planter and its components, 1)Disc Coulter, 2)Gauge wheel, 3)Soil 
covering disc, 4)Press wheel, 5)Seed hopper, 6)Down force spring, 7)Parallelogram linkage 
With these in mind, few design ideas were suggested. Figure 3-3 shows a couple of 
sketches for conceptual design that were done by hand. In the first sketches and conceptual 
design step, the main objective was to keep the planter easy to pull, small so that can be 
connected to the robot, easy to build, inexpensive and as light as possible so it does not require 
huge power. When the decision has been made on the general idea, a first sketch of 3D model 
was generated in SolidWorks. Figure 3-4 shows the 3D model of the modified planter. In this 
figure, the parts that are shown in grey, are the parts that are used from the existing planter 
without any change, and the blue parts are the developed and new parts that further analysis has 
been performed on them. 

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Figure 3- 3- Sketches of the design of two planters, utilizing disc coulter 

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Generally it can be said that, most of the research and analysis has performed on the parts 
that are in contact with the soil and their attachments (Figure 3-4). These parts can be 
categorized in groups for easier further analysis, 

Furrow opener assembly: Disc, gauge wheel, disc holder and depth control link 

Packing assembly: Press wheel, Press wheel links, Spring connection and 
extension spring 

Seeding assembly: Seed drop tube, runner type opener, power transmission and 
vacuum system 

Connection assembly: Main spring, vertical connection bar, horizontal connection 
bar and lifting mechanism. 
Figure 3- 4- SolidWorks model of the new designed planter 

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Details of each of these groups and their parts that are studied for design purpose come in 
order.