1. Design Of Unmanned Aerial Vehicle
For Agricultural Purposes

2. •
Every year billions of dollars are spent on the agricultural fields to
enhance the life of the crops. This is achieved by the use of strong
detrimental pesticides.
•
To ameliorate the health of a farmer who encounters the use of such
pesticide we are developing a UMAV (unmanned Ariel Vehicle) .
•
The purposed work presents design of a vehicle which can remotely
spray the pesticides under video surveillance in the agricultural field.
•
This UMAV features an economical design such that its affordability and
reliability can be assured.
•
The structural design would be carried out by use of CATIA/SolidWorks.
Later stress analysis would be conducted by use of ANSYS.
•
Farmers in underdeveloped and developing countries would be
recommended to make use of this device as working standards for an
average farmer is not high in those countries.
Abstract

3. Project Objectives
•
Select an appropriate material to ensure proper strength and
stability to the structure.
•
To design a model on Solidworks/CATIA based on based on
dimensions decided.
•
The structure should have provision for spraying pesticides.
•
The do the required calculations and verify the results using an
output from ANYSIS.
•
Formulate the results and check if there can be any further
scope for improvement.
•
Setting up a platform for future research on the work done.

4. Literature review
Author Methodology Salient Results
M. Pérez-Ortiz
(2015)
Observation They used uav for aerial surveillance to map
weeds in sunflower crop to increase
production buy use of camera footage.
``A semi-supervised system for weed mapping in
sunflower``
Mr. Kalpesh N. Shah
(2014)
Design & analysis Designed structure of quadrotor and
performed design analysis using ansys
``Quadrotor An Unmanned Aerial Vehicle``
Michael Bronstein
. (2015)
Structural analysis They used a predesigned Aircraft and
performed ansys by using stick model and
3d shell model. “Assessment of dynamic effects
on aircraft design loads: The landing impact case”
Bruno S. Faiçal
(2014)
application Use of uav to spray pesticides in agricultural
field “The use of unmanned aerial vehicles and
wireless sensor networks for spraying pesticides”

5. Frame Restrictions
•
The frame shall have a provision for spraying hence structure
should have proper sections available for placing spray nozzles.
A triangular shape was decided from a number of geometrical
shapes. The benefit of selecting a triangular shape is as follows:
•
Shape helps to reduce the overall weight and at the same time
give stability.
•
The manufacturing of a standard shape is easy and simplifies
design.
Designing on SOLIDWORKS
•
The project involves designing the above proposed design on
either CATIA or SOLIDWORKS. We had chosen solid works
because of its simplicity and user friendliness.

6. Components Weight
Components Description Weight (kg)
Battery weight 1.3
liquid pesticides container 1.4
Masterflow 12v Portable reciprocating compressor 1.3
Piping and nozzle arrangement 0.2
Electrical components 0.1

7. Aluminum
•
Low Density and therefore low weight
•
High Strength
•
Superior Malleability
•
Easy Machining
•
Excellent Corrosion resistance and
•
Good Thermal and Electrical Conductivity

8. Magnesium alloy
•
The lightest of all structural metals, magnesium
preserves the light weight of a design without
sacrificing strength and rigidity. This benefit is
important when portability is a key element of the
product design such as UMAV.
•
The elastic energy absorption characteristics of
magnesium result in good impact and dent
resistance and energy management.
•
Magnesium shrinkage rates are more consistent and
predictable in comparison to other nonferrous
metals.

9. Delrin/Acetal
•
The Acetal resins are among the strongest and
stiffest of all thermoplastics,
•
good fatigue life,
•
low moisture sensitivity,
•
high resistance to solvents and chemicals,
•
good electrical properties.

10. Pesticides Drift
•
Pesticide spray drift can be described as the physical
movement of a pesticide through air at the time of
application or soon thereafter, to any site other than
that intended for application.
•
When pesticide solutions are sprayed by ground
spray equipment or aircraft, droplets are produced
by the nozzles of the equipment. Many of these
droplets can be so small that they stay suspended in
air and are carried by air currents until they contact a
surface or drop to the ground.
•
A number of factors influence drift including weather
conditions, topography, the crop or area being
sprayed, application equipment and methods, and
decisions by the applicator.

11. Height
•
The higher the nozzle is above the crop or target, the
more opportunity the wind or air flow has to move
droplets from the intended site.
•
Spray equipment operated at high speeds can create
turbulence in the airflow around the machine that can
catch small droplets and make them vulnerable to
drift.
•
Determine the optimum height for the particular
nozzle from the nozzle literature to reduce drift
potential. If the nozzles are too low, uneven patterns
or skips may occur. To prevent the boom ends from
striking the ground, nozzle heights are frequently much
higher than optimum on large application equipment
traveling at higher speeds.

12. Moments of Aircraft vs. Quad rotor
• Roll (tilting left and right) - Controlled by increasing speed of one motor and
lowering the opposite one.
• Pitch (moving up and down) - Same way as roll, but second pair of motors
are used.
• Yaw (turning left and right) - Controlled by turning up the speed of the
regular rotating motors and taking away power from the counter rotating.

13. Moments of Aircraft vs. Quad rotor
Cont.

14. Bending stress

15. Shear force
•
Shear stress is a stress state where the stress
is parallel to the surface of the material, as
opposed to normal stress when the stress
is vertical to the surface.

16. Mathematical Calculations•
σ = 0.08046 * F (N/mm2
)
•
T = 7.3486 * 10-4
F (N/mm2
)
•
Stress = σ + T
Stress = 0.08046 * F + 7.3486 * 10-4
F
Stress = .08120 F (N/mm2
)
•
Stress in various Materials

Aluminum
•
Stress = .08120 F (N/mm2
)
•
F = 88.504 N
•
Stress = 7.18 N/mm2
or 7.18 * 106
Pa

Magnesium Alloy
•
Stress = .08120 F (N/mm2
)
•
F = 60.944 N
•
Stress = 4.95 N/mm2
or 4.95 * 106
Pa

Delrin
•
Stress = .08120 F (N/mm2
)
•
F = 50.148 N
•
Stress = 4.07 N/mm2
or 4.07 * 106
Pa

17. Designing

18. Aluminium Analysis
Forces Acting on the frame Magnitude (Newtons)
Force A: Propeller Force 88.504
Force B: Propeller Force 88.504
Force C: Propeller Force 88.504
Force D: Propeller Force 88.504
Force E: Gravity Effect 9.8066 (m/s^2)
Force F: Battery 12.258 N
Force G: Compressor 12.258 N
Force H: Liquid Container and electrical Components 14.709N

19. Forces and Pressures

20. Deformation Plot on ANSYS

21. Stress Plot on ANSYS

22. Summary of Results
Parameter Aluminum Delrin Magnesium
Maximum
Deformation
.5289 mm 5.3217 mm 4.8043 mm
Maximum
stress
7.4276 * 10^6 Pa 4.3006 * 10^6 Pa 5.17146 * 10^6
Pa
FOS SAFE SAFE SAFE

23. Interpretation
•
We can see that maximum deformation occurs in
Delrin while minimum occurs in aluminum. Stress
induced in Delrin is least when compared to
aluminum and magnesium.
•
Aluminum is most expressive of all three materials
while Delrin and magnesium follow after that
respectively.
•
As compensation between the cost and strength we
will select Delrin to be the preferred material.
•
Also the results calculated my mathematical
modeling are close to the above ANSYS results.