Modified Design of a Precision Planter For a Robotic Assistant Farmer

5-2-1- Outdoor tests: 
Outdoor tests were performed on the north-west side of the College of Engineering 
building, University of Saskatchewan (See Figure 5-3).
The main objective of this test was to observe the performance of the planter and mobile 
robot in, 
- Lifting and transportation
- Cutting the hard soil, opening the furrow and closing the furrow 
- Residue handling performance of the planter 
The planter was attached to the Grizzly mobile robot, lifted up from the ground, and 
transported to the test area by the mobile robot (See Figure 5-4). When the robot and planter 
were in the place to start the test, the planter was set down on the ground, and the depth of cut 
was set to 50 mm, and then it was pushed into the soil to start the test.
The soil in that area has been used to cultivate grass, and it has become packed and hard 
over time. Therefore it has a hard soil compared to the common medium packed soil used for 
corn planting. The water content of the soil was about %15 on the day of the test, 31
st
of October 
of 2013. The grass on the soil was used to simulate the residue which is available in farms, when 

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practicing no-till farming. The reason this area was chosen for test was its ease of transportation 
of the mobile robot and the new planter set. 
Figure 5- 3- Location of the outdoor tests, north of engineering building 
Figure 5- 4- The set of two planters, attached to the wheeled mobile robot in transport 
position 

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So when the disc and other parts are engaged with the soil, the robot goes a straight path. 
The planter opens two furrows and later closes them after seeding. Each furrow is 50 mm deep 
and two furrows are 380 mm away from each other. Figure 5-5 shows the opened furrow and its 
width. It can be seen that opened furrow is wider than the width of a corn. It can be estimated 
easily form the size of the seed drop tube that the width of the furrow is about 40 mm. Although 
the residue which is available in a farm is more packed than the grass on the test field, but, it can 
be observed that disc coulter has been successful in cutting through a light amount of residue 
(grass).
Figure 5-6 shows the line remaining from the closed furrow after was opened by the disc. 
It can be observed that the disturbance that is caused by this implement is very small. Fewer 
disturbances in the soil mean less loss of moisture and nutrients of the soil. Also this picture 
show how complete the press wheel has done its job in covering the soil. If the soil is not 
covered properly, the seed may not germinate well, or it can even be blown away by wind or can 
be eaten by small animals and birds. 
Figure 5- 5- The furrow opened by the planter 

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Figure 5- 6- The closed furrows by press wheels 
The results that were obtained from this outdoor test were satisfactory and as expected. 
This was the very first time that designed planter was tested in contact with the soil. In all the 
steps of the test, from lifting off the ground and transportation to opening the furrow and closing 
it, its performance was as expected.