UAVs in Agriculture - Intern Project Summary

17 July 2015

UAVs – Intern Project SummaryNetworks and Systems

David Minn

UAV’s – Intern Project Summary

Contents

1. UAV Background

2. Blockers

3. Project

- Opportunities

- Application

- Structural Design

- System Design

4. Testing and Data Analysis

5. The Future

6. Highlights


The Names

• UAV - Unmanned Aerial Vehicle (Often referred to by academic researchers)

• Drone (Most commonly used by the media and recognised by the public but for commercial applications has negative connotations)

• UAS - Unmanned Aircraft System (Referred to within CAA regulations)• SUA – Small Unmanned Aircraft (The acronym currently preferred by

the CAA)• RPAS - Remotely Piloted Aerial System (Now used across Europe

within the context of a proposed new regulatory system)

UAVs are not a survey technology but a remotely controlled, low aerial platform for carrying a wide range of sensors.

A lot of different names are used to describe the system:


What is a UAV?

UAV – UNMANNED AERIAL VEHICLE

Multirotor Fixed Wing Hybrid

• Advantages and disadvantages for using all three• Which type is used depends completely on what application it is being used for


What is a UAV?

UAV – UNMANNED AERIAL VEHICLE

Smal

l

Big


Why UAVs?

Earth Observation Satellite Communication Satellite Navigation

• Refine and complement Data

• Military UAVs use SatComms

• Deployable commsunit

• Robust Positioning• Uses GPS for flight

positioning

General Transferrable Skills

• GNSS Expertise• Data Processing• Machine to Machine• System design (power, weight, payload)• Data fusion


Why UAVs?

Growing Industry:

• Manufacturers are seeing the change in sale numbers

- 3 major manufacturers (Parrot, DJI, 3D Robotics)

• UK RPAS Cross Government Working Group:

- Help the UK lead the way in the market

- All aspects are covered

• Media attention (daily news)

RPAS – Remotely Piloted Aerial System


Rules and Regulations

CAA – Civil Aviation Authority:

Independent specialist aviation regulator and provider of air traffic services

EASA – European Aviation Safety Association

Agency of the European Union (EU) with regulatory and executive tasks in the field of civilian aviation safety

0 20 150

No permit required unless being used for commercial gain

Requires permit

EASA regulation states that a permit is needed


Rules and Regulations

Why is training required and why are rules necessary?


UAV Blockers

Battery Technology

Larger battery for more power means heavier load therefore more power is needed for longer flight time and extra components.

Sense and Avoid

Rules Restrict

Apps

Currently the rules are preventing the market from growing to its potential.

UAV is not fully autonomous without a safe sense and avoid system (not been exploited for sUAS)


Project Outline

Market opportunity – Read around the current UAV applications

that exist worldwide

UAV Concept – Come up with and finalise an idea for the UAV

(Must be a multirotor)

Design Phase – Use CAD software to design the structure and

calculate the necessary electrical components for the system.

Integration/Assembly – Combine all the system components and

put them on to the frame.

Test plan – Create a plan for the chosen application

Flight testing and mission validation – Test the application and

conclude the project.


UAV Opportunities

ApplicationsAgriculture

Archaeology

Journalism

Delivery

Humanitarian Work

MilitaryMapping

Photography


Current Examples – Visual Working


Events

• Commercial UAV Show• Advanced Engineering Show • SUAS – Enforcement Tool or Security

Threat• KTN/ARPAS RPAS Conference• UAVs - Unravelling the Mystery

Information:

• More case studies• Some industries are looking at ways of using UAVs whilst others have genuine

problems that can be addressed by the use of UAVs• Agriculture is a major player in the industry • Network Rail could use their closed environment to show safe usage of UAVs• Rules need to change for the industry to thrive


Agricultural Findings – Elms Farm

Elms Farm:- Located between Grove and Wantage- 300 Hectares (420 full sized football pitches)- Produce wheat, barley and beans.- Farmer – Robert Benson

Key Facts:- Weather dependent- Agronomist comes once a week for an hour (Not enough time) –

Recommends chemicals- Every 5 years a soil sample will be taken at the same GPS point on the farm- Hard to monitor the whole farm as its too big- Target specific areas (2 hectares rather than 50)- Problems that farm encounters:

- Rust- Mildew- Yellow rust- Slugs(These can take out crops in a few days if not spotted)


Application

𝑵𝑫𝑽𝑰 =(𝑵𝑰𝑹 − 𝑹𝒆𝒅)

(𝑵𝑰𝑹 + 𝑹𝒆𝒅)

‘ Design a multirotor for the agricultural purpose of providing end

users with more accurate data of their land.

The Multirotor will capture NDVI (Normalised Difference

Vegetation Index) imagery and transmit data back to a ground

station for processing. The end user will then know the health and

status of the crops and soil.

The data collected will help end users maximise the yield

produced.’

Photo from http://www.publiclab.org/wiki/near-infrared-camera

𝑵𝑫𝑽𝑰 - Normalised Difference Vegetation Index

𝑵𝑰𝑹 – Near Infrared

http://www.publiclab.org/wiki/near-infrared-camera


Application

𝑵𝑫𝑽𝑰 =(𝑵𝑰𝑹 − 𝑹𝒆𝒅)

(𝑵𝑰𝑹 + 𝑹𝒆𝒅)

𝑵𝑫𝑽𝑰 - Normalised Difference Vegetation Index

𝑵𝑰𝑹 – Near Infrared


Structural Design

• Designed on SolidWorks (multiple iterations)

• Hexacopter (6 motors)

• Built from Carbon fibre sheets and tubes (Dremel used)

• 3D printed connectors (Carbon Fibre PLA)

• Metal and plastic screws

• Nylon Spacers

PLA – Polyactic Acid – Thermoplastic


Structural Design

Adjustments:

• Metal coat hangers used to dampen• Extra layer for controller• Sugru used to dampen• Reprint 3D printed parts once broken

Final structural design before components were mounted


System Design

Battery

PDB PDB PDB

ESC

ESC

ESC ESC

ESC

ESCMotor Motor

Motor

Motor

Motor

Motor

Power Module

Flight Controller

PDB – Power Distribution BoardESC – Electronic Speed Controller

Gimbal


System Design

To aim for the best system performance and choose components I used ecalc (online multicopter component calculator):

I then placed the different variations into an excel spreadsheet to compare which were best:


System Design

• I based my choice of components on the outcome that my spreadsheet provided me with and a few other factors.

• Waterproof motors were chosen as they can be used outside in any weather condition.

• The use of light components was necessary to provide a balance between power and weight.

• Each component was checked to make sure that the voltage and current boundaries were compatible with one another.

• A calculation was made to estimate that the battery would last 14 minutes

Equation:

𝐵𝑎𝑡𝑡𝑒𝑟𝑦 𝐶𝑎𝑝𝑎𝑐𝑖𝑡𝑦 (𝑚𝐴ℎ)

𝐿𝑜𝑎𝑑 (𝑚𝐴)= 𝐹𝑙𝑖𝑔ℎ𝑡 𝑡𝑖𝑚𝑒 (ℎ)


APM Flight Controller

• APM 2.6• Open Source Controller• Pre Programmed Arduino• Uses external magnetometer

(Compass)• GPS for waypoint navigation• Comes with computer software

(Mission Planner)

• Calibrate the compass• Calibrate the accelerometer• Auto PID calibration• Add components (ultrasonic sensor, wireless

telemetry, camera gimbals etc)• Pre programmed flight modes• Link

../../../Desktop/Mission Planner.lnk


APM Flight Controller

Flight Controller

ESCESCESCESCESCESC

GPS

RC Receiver

Throttle

Roll

Pitch

Yaw

Gear

AUX 1

Telemetry Antenna

Radio Transmitter Computer

Ground Control

Camera Gimbal


Final Prototype Design


Testing (1)

1. Compass Calibration

2. Accelerometer Calibration

3. Radio Calibration

4. ESC/Motor Calibration


Testing (1)






Testing (1)






Testing (1)






Testing (2)

Adjustments:

PID values weren’t optimum leading to high sensitivity therefore PID calibration was required.

PID – Proportional Integral Derivative – A control loop feedback mechanism.


Testing (3)

Adjustments:

Legs were added with vibration absorption. Controller adjusted to compensate for PID values. 3D printed motor holder snapped. Camera needed to be added.


Camera

• GoPro Hero3 White edition- Light- Durable- Adjustable- Wifi Enabled- Separate internal battery

• Modify with InfraBlue lens- Take GoPro apart- Remove Fisheye lens- Replace with new lens

Attach GoPro to stabilising gimbal!


Farm Test

• Elms Farm• Conditions: Hot and Windy• Problems: Battery and Wind• Imagery attained• Crashes


Image Processing

This is the raw image taken from the Infrablue lens on the GoPro


Image Processing

This is the same image with slight atmospheric correction added to it


Image Processing

This is the NDVI after the image had been processed


Image Processing

These images show all three representations separately

Results

The major results consisted of the following:

• Hexacopter built

• Fully controllable and adaptable UAV

• Imagery attained

• End user requirements captured and utilised


Future

Recommendations:

• More work on the control system and learning its advantages

• Create a covering for the UAV (e.g. Dome)• Gather more images and learn how to analyse them• Create a system architecture to aid the community in

sense and avoid technology• Link the UAV into a machine to machine network to add

another data set (e.g. Connected Farm)• Research into an application that links Satellite and UAV

data• Control camera remotely• Research the use of different innovative sensors


Highlights

• Building a UAV from scratch!

• Seeing a project through from start to finish.

• Networking internally and externally (Events)

• End user engagement (Farm Visits)

• Speaking with a variety of people here at the Catapult both

professionally and socially

• Hands on technical experience

• Learning and building on new and existing skills

• External meetings and presentations (HVM Catapult, Sheffield

University)

• Company working environment

• Annual Conference

• CAKE!

• And CAKE!

Thank You