Designing Purpose-Built Drones for Ardupilot Pixhawk 2.1: Build drones with Ardupilot

Designing Purpose-Built Drones for Ardupilot Pixhawk 2.1

Build drones with Ardupilot

Ty Audronis

BIRMINGHAM - MUMBAI

Designing Purpose-Built Drones for Ardupilot Pixhawk 2.1

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First published: December 2017

Production reference: 1271217

Published by Packt Publishing Ltd.

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ISBN 978-1-78646-916-8

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Credits

About the Author

Ty Audronis has been called a technology-age renaissance man. He’s a professional drone pilot, post-production specialist in the entertainment and media industries, a highly experienced interactive game developer, and an accomplished digital artist. He has worked for companies ranging from frog Design to California Academy of Sciences in roles, where he has worn many hats.

Ty has been programming software and games since 1981 (when he was 8 years old) professionally. He majored in Computer Generated Animation and Visual Effects in college (where he won Best Animation for the entire CSU system – a Rosebud Award). He has been building drones since the days when sensors and components had to be torn out of cell phones and game controllers.

Ty is also a mentor, having taught many interns his skills and speaks regularly at venues, including Interdrone. He also serves on the advisory board for the Society of Aerial Cinematographers and for Genarts (now Boris) Sapphire.

About the Reviewer

Ayan Pahwa is an embedded software engineer from New Delhi, India currently working at Mentor Graphics - a Siemens business with 5 plus years of experience in building and racing first person view multi-rotor drones. His professional work areas mainly focus on embedded firmware, device drivers, automotive IoT, and Linux system programming. He has co-founded SDIoT for flourishing drone and other new technologies within local communities. His drone aerial videos can be viewed on his YouTube channel.

Ersin Gonul is a senior design engineer at Turkish Aerospace Industries in Ankara, Turkey. Previously Gonul worked as R & D engineer for companies which they develop unmanned aerial vehicles. He graduated with honors from Selcuk University in Electrical and Electronics Engineering and also he holds a Master degree of Electrical and Electronics Engineering from the Hacettepe University, Ankara. His expertise based on helicopter autopilots and unmanned systems. He is passionate about aviation, multicopters, VTOLs and their control systems. He also holds a Private Pilot License (PPL-H).

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Table of Contents

Preface

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Downloading the color images of this book

Errata

Piracy

Questions

Drones 101

Introduction to drones

Purposes for drones

Types of drones

USV drones

Rovers

Submersibles

UAV drones

Multirotors

Fixed-wing drones – airplanes

Hybrid drones – VTOL

Helicopter drones

Dirigible drones – Blimps

Ardupilot 101 – A quick overview of Pixhawk 2.1

Safety and best practices

Summary

Your First Drone - An Autonomous RC Car

Our rover

Kitbashing

Rustler VXL

Planning and limitations

Identifying the components

Planning the placement of Pixhawk

3D modeling, printing, and silicone molding

Measure five times, print once

Model it in 3D

Print it in 3D

Preparing for molding

Pouring the mould

Demolding and curing

Hooking up your Pixhawk

Global Positioning System (GPS)

Radio telemetry

RC receiver

Connecting the brain to the body

Programming the Pixhawk for our (basic) rover

The wizard

More calibration...

Testing and driving

Setting waypoints

Summary

A Drone for Hunters – Autonomous Duck Decoy

Spawning a marketable deal

Outlining the scope before you design

Choosing the kitbash boat

Designing the duck body for 3D printing

The basics of 3D modeling

Modeling with subdivs

Box modeling 101

Knifing polygons

Extruding and shifting

Making the duck hollow

Freezing curves into polygons – subdividing

Booleans

Printing large 3D models

Testing for water-tightness

Installing the propulsion system

Steering and electronics

Hooking everything up!

Summary

A Drone for Golfers

The design

Using tank locomotion

Adapting Pixhawk for skid-steering

Using Bluetooth to control Pixhawk with a phone

Using LIDAR to avoid obstacles

LIDAR 101

Making LIDAR work

Mounting the module

Configuring LIDAR with Mission Planner

Summary

Introduction to UAVs

Safety concerns

Propellers - flying cuisinarts

Designing for air versus ground

Weight

Power/lift

Fuel - battery

Learning some physics

Designing a multicopter airframe

Symmetry

Even numbers

Blade clearance

Designing a fixed wing - airplane

Wing design

Summary

A Simple Multicopter Drone

What is 360 VR video, and why make a drone for it?

Spec-ing out the parts

Starting with the payload

Choosing the gimbal

Landing gear

A first-person view – FPV system

The actual aerial platform – drone

Batteries

Running the numbers

Assembling the drone

Too many freakin' wires!

GPS on a stick

Rails are awesome

Anything loose? Tuck it away and tie it down

Hooking up the ESCs to Pixhawk

Configuring Pixhawk and Mission Planner

The initial configuration of Pixhawk

Configuring the ground station

Using joysticks to control a drone

Setting up video

Final configuration before test flights

Summary

The Holy Grail - A Fixed Wing Drone

Why this particular airplane kit?

The assembly

Placing the Pixhawk

Placing the components

Tuning a fixed wing aircraft with mission planner

Configuring the pitot tube

Setting up the LIDAR range finder

Setting up for tuning

Fixed wing flight modes

Setting flight modes

Autotune level

The tuning process

Your maiden flight

AUTOTUNE flight

Taking off and getting ready to tune

Entering AUTOTUNE

How to fly in AUTOTUNE

Testing AUTOTUNE

Autopilot tune

Setting up the mission

Flying the tuning mission

Auto-landing tuning

TECS tuning

Testing and fine tuning TECS

Auto-landing setup and parameters

The testing

Summary

The Principles of VTOL with Pixhawk

The types of VTOL

The hybrid VTOL

Thrust vectored VTOL

Designing your first VTOL

The challenge

The simple gets more complex

The (re-imagined) airframe

Creating our shopping list

The final plan

Implementing Pixhawk

Test and tune before making the leap

Setting up the firmware

Quadplane flight modes

Transitioning from VTOL to airplane

Recommended VTOL RTL procedure

Notes before attempting any transitions

Summary

Programming Ardupilot

The Flight Data interface

The Flight Plan Screen

The Initial Setup screen

Wizard

Mandatory hardware

Optional hardware

Config/Tuning screen

Planner

Flight Modes

Basic Tuning

Standard Params

Advanced Params

Full Parameter List

Full Parameter Tree

The Simulation Screen

Mission Planner terminal

Summary

Preface

We live in the drone age. Drones currently serve purposes in defense, entertainment, and in some countries, package delivery. However, the drone age is still in its infancy. There are a plethora of uses for drones that are just on the cusp of being discovered; drones for mapping, drones for convenience, and even drones for scientific research.

This book will walk you through the design process for drones that navigate the air, land, and even the sea. We will show you how to come up with ideas, overcome the limitations of budget and current technology, and implement them. However, a drone without a brain is just an RC vehicle. We’ll show you how to integrate the Pixhawk 2.1 guidance system into your drone and how to add peripherals and sensors to Pixhawk to make ordinary RC vehicles into smart drones that serve purposes.

What this book covers

Chapter 1, Drones 101, introduces you to the world of drones and explains that there are many types of drones. We also give you a high-level overview of Ardupilot and Pixhawk flight controller systems. Finally, we walk you through some of the safety best practices to minimize the risks associated with prototyping new drones.

Chapter 2, Your First Drone - An Autonomous RC Car, walks you through kitbashing (using an existing) RC car and turning it into a surface drone (a rover). We show you the basics of designing, 3D-printing, and even molding new parts for your rover to adapt it to Pixhawk. You will be given even more familiarity with the plugs on the Pixhawk 2.1 board and how sensors are attached, as well as a basic overview of the Mission Planner interface. By the end of this chapter, you will have an understanding of how to create a rover using Pixhawk 2.1, a GPS sensor, and a remote telemetry transmitter.

Chapter 3, A Drone for Hunters – Autonomous Duck Decoy, takes the principles of a rover and applies them to the open water. This chapter focuses largely on the process of coming up with a marketable idea and planning your design. You will be shown how to cannibalize parts from an RC boat and implement them into a custom 3D-printed hull (a duck). We will also educate you on the pitfalls of a water drone with regards to waterproofing, ballast, and even water-cooling your drive motor.

Chapter 4, A Drone for Golfers, takes purpose-built rovers to the next level by showing you that drones can fit into almost any market demographic: in this case, golf. We will build a golf trolley on an existing RC golf trolley’s frame and motor system. It implements skid-steering and Bluetooth for telemetry and control, enabling it to follow a golfer that is carrying a phone in their pocket. Also, we will integrate a new sensor: a LIDAR rangefinder that allows the trolley to avoid obstacles while it follows the golfer autonomously.

Chapter 5, Introduction to UAVs, transitions the reader from the surface to the air. Aerial drones represent a whole new level of complexity. With weight considerations, balance, and safety concerns being the focus of this chapter, you will learn to think more like an aeronautical engineer when designing your aerial drones.

Chapter 6, A Simple Multicopter Drone, shows the reader how to build and tune a multicopter drone. We adopt a GoPro gimbal (designed to stabilize a GoPro camera) to hold a 360° VR camera (a Ricoh Theta S). We also walk you step-by-step through the Mission Planner interface to get a ground station up and running, which will display a video on a laptop screen, along with the heads-up display and even allows you to fly the drone using gaming joysticks.

Chapter 7, The Holy Grail - A Fixed Wing Drone, walks you through designing and setting up a fixed-wing drone. We will integrate an airspeed sensor (pitot tube) and use a rangefinder again but this time to sense altitude from the ground to assist with autonomous landings. This chapter largely focuses on the Mission Planner software. Using it to tune a fixed-wing drone to fly properly, we will execute autonomous missions and even land with no input from the pilot.

Chapter 8, The Principles of VTOL with Pixhawk, is a bonus chapter added due to the popular demand from the drone community. VTOL (Vertical Takeoff and Landing) drones are airplanes that can also hover and land/take off like a helicopter. Rather than build a drone in this chapter, we walk you through the concepts of planning, building, and tuning a VTOL aircraft.

Chapter 9, Programming Ardupilot, is largely a reference chapter designed to give you quick reference to the Mission Planner interface and all of the basic parameters therein.

What you need for this book

This book guides you through building various types of drones by example. You do not have to buy all of the materials, nor even build along-side. All this book really requires from you is an imagination, which we hope to spark by example.

Who this book is for

This book is intended beginners and intermediate drone enthusiasts. But at some point, even professional designers may benefit from the book’s contents.

Conventions

In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: The next lines of code read the link and assigns it to the to the BeautifulSoup function.

New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: In order to download new modules, we will go to Files | Settings | Project Name | Project Interpreter.

Warnings or important notes appear in a box like this.

Tips and tricks appear like this.

Reader feedback

Feedback from our readers is always welcome. Let us know what you think about this book-what you liked or disliked. Reader feedback is important for us as it helps us develop titles that you will really get the most out of. To send us general feedback, simply email [email protected], and mention the book's title in the subject of your message. If there is a topic that you have expertise in and you are interested in either writing or contributing to a book, see our author guide at www.packtpub.com/authors.

Customer support

Now that you are the proud owner of a Packt book, we have a number of things to help you to get the most from your purchase.

Downloading the color images of this book

We also provide you with a PDF file that has color images of the screenshots/diagrams used in this book. The color images will help you better understand the changes in the output. You can download this file from https://www.packtpub.com/sites/default/files/downloads/DesigningPurposeBuiltDronesforArdupilotPixhawk21_ColorImages.pdf.

Errata

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To view the previously submitted errata, go to https://www.packtpub.com/books/content/support and enter the name of the book in the search field. The required information will appear