PRE2020 3 Group5

Emergency Drone

Group Members

Name	Student ID	Department	Email address
Pepijn Hundepool	1427520	Mechanical Engineering	p.c.j.hundepool@student.tue.nl
Lucas Commissaris	1451065	Mechanical Engineering	l.f.h.commissaris@student.tue.nl
Sven Passier	1448781	Mechanical Engineering	s.w.l.passier@student.tue.nl
Bram van den Buijs	1464647	Applied Physics	b.v.d.buijs@student.tue.nl
Stijn Borgers	1495968	Applied Physics	s.borgers@student.tue.nl

Problem statement and objectives

The popularity and usage of compact unmanned aerial vehicles (UAVs), better known as drones, has been increasing radically over the past few years . For only a rather small amount of money, you can already get yourself a drone with some basic abilities. In general, three types of drone users are distinguished. The majority of the drones that are made are made for military purposes. An increasing part of the drones are made for consumers (e.g. hobbyists) and commercial usage. The commercial usage groups will be the point of focus for this project. These drones can have a broad range purposes, such as 3D mapping, delivery, inspections, data transmissions, video collection, etcetera. Although the commercial usage group represents the lowest percentage of sales of the three aforementioned sectors, the revenue value in 2016 was about 60 percent more than the one from consumer purchases. This phenomenom is mainly caused by the fact that price tags of about $100,000 are no exception in the commercial.

A sector that does not really match the term 'commercially' as it regards the type of institution, but does regarding the production price tag, are drones used by governmental bodies. In specific it concerns departments that are of key-importance in emergency situations, with the three most central ones being respectively the police, firefighting and medical (ambulance) departments. In these departments, try-outs and permanent involvements of drones become more and more part of the job . However, since these drones often include high-advanced technologies, their production costs can rise to serious heights. A proper police drone for example lies in the purchasing range from $50,000 to $200,000 .

This project aims to develop a new type of drone, which will be able to carry out tasks for more than one of these departments. Roughly sketched, this will result in a drone with a range of standard functions, on which a specific variation of equipment can be (de)attached. This multifunctional drone will have multiple benefits over the development of drones that are specified per department. A benefit, is that drones can be used more efficiently at for instance an incident or natural disaster, where often more than one department is providing assistance. Since the equipment can be varied for multiple departments, different tasks can be executed with the same drone. As a result, when at a certain moment in time a department is not using their drone(s), other departments can make use of it instead.

After doing a [#Sampeling the users | user analysis] we concluded the best drone to develop would be one that has the ability to give a birds eye view to the users because this type of drone is beneficial to all departments.

Deliverables

This project aims to have the following deliverables at the end of the quartile:

• A study on the experiences and thoughts of the primary users on the development of drones in their expertise.

• A conceptual CAD model of an emergency drone, which should be able to be used by all three main departments. This model will focus rather on the design and type of functions it should be able to perform, to a great extent based on the primary user study, than to show a detailed view on the exact controls that would be required.

• A FEM-analysis on the CAD-model, to show the impact of external forces on the drone's design

• A simulation of the CAD model in Simcenter to show how the drone will propel

• A wiki page shows the consecutive steps that have been taken to accomplish the deliverables stated above

USE Analysis

In this section the different stakeholders of our project will be investigated and elaborated on.

Users

The primary users of the emergency drones are the civil servants that work in the fire, police and medical department. To be more specific: within the fire department the drone will be used as a fire-reconnaissance tool, within the police department it will be used for surveillance and finally within the medical department the drone will be used for the transport of goods between hospitals.

The secondary users are all civilians. Civilians could be trapped inside a burning building, they could be under surveillance or they could be in a hospital with the need for a certain essential good like blood. In all these cases, civilians are on the receiving end of a emergency drone.

Sampling the users

We wanted to confirm and further investigate the user needs, so we set up a questionnaire for each of the three departments. We asked a few questions about technical specifications and how drones could be used best. We also asked them about their attitude towards the implementation of drones into their work to confirm that the users would want to use drones, this is not necessary for the result of our project but it does help confirming the usefulness of it.

After realizing that an interview would be more beneficial for our research, we conducted one. Elaboration can be found in the section below. We did not get any response from the police department. Neither with the questionnaire nor the interview (of which the emails were send to different addresses).

Questionnaire

The answers we got were the answers we expected but we were still missing something. We realized that the questionnaire would either need to be reformulated so that the answers would be useful to us or we had to find another way to get information. In the end we decided to conduct an interview. The reasoning was that if we were to get in contact with even one person that is working with drones, we would be able to obtain more knowledge then with an answer of a multiple choice question. Even an answer to an open question would be subpar.

The results of the questionnaire can still be found in Appendix C.

Interviews

To have a more in-depth understanding of certain technical difficulties and choices, we interviewed some people from each of the three different sectors. These people specialized in the development of the drones to support their respective sectors. We have interviewed 5 people in total and summarized their answers to the different interview question. We will first introduce the participants. Below that will be questions and summarized answers (results).

People

Here the people that we have interviewed will be introduced.

Fire department:
1. Mark Bokdam (Linkedin): Chief officer of the fire department in Twente and a board member at the SWOD foundation on behalf of the Dutch Fire Department. He has worked for the fire department for over 11 years and is the contact for any questions about the drones teams of the fire department.
2. Robbert Nijs (Linkedin): Policy advisor IRA (information, research and analysis) for Mid- and West-Brabant. 19 years of experience with working for the fire department

Medical department:
1. Jaap Hatenboer (Linkedin): Vice president and the Policy and Innovation manager at UMCG Ambulancezorg. In his daily life he deals with new developments surrounding transportation in the health sector. But also the organization of the healthcare department he works in.
2. Mirjam Meerkerk: Paramedic and part of Axira. Axira is a partnership between independent regional organizations that now operates nationally for ambulance care. They say that they combine their knowledge and experience to make innovations faster, better and cheaper . In Anne-Jan's daily life he encounters accidents, cerebral infarction, people in panic and he uses psychiatry to calm victims and/or their relatives.

Questions and answers

Here you can find the questions and the answers from the interviews. The answers will be combined and summarized for the convenience of the reader.

Fire department:

- How do you see drones be used by the fire department?

The drones that are used in The Netherlands today are for areal reconnaissance. These drones are equipped with an optical camera (DJI Zenmuse Z30) and an infrared camera that also has an optical camera inside of it (DJI Zenmuse XT2), so it can produce a video with both optical and infrared footage overlapped.

- Drones are not used to extinguish fires in The Netherlands. Why?

Water is quite heavy, so to compensate the forces to carry and fire this water, the drones will have to have quite a lot of power. This means these drones will be very heavy, think anywhere from 30 to 400 kg. China is already testing with these drones. Robert Nijs doubts that these things can extinguish fires that are inside the building. These drones might be able to carry a good amount of water up, but a fire truck will most of the time be more useful. The one exception is if there is a fire in a high story building (which are quite common in China) where a fire truck will probably have difficulties reaching that high, but a drone can just fly up there. According to Mark Bokdam, The Netherlands will start experimenting with firefighting drones within 5 years.

- Do you think it is possible? Maybe even autonomously?

According to Mark Bokdam, The Netherlands will start experimenting with firefighting drones within 5 years. To have a drone being fully autonomous is a whole other question because a drone needs to be supervised otherwise we encounter a responsibility problem. Who will be held responsible for the things that the drone does? The supervisor? The software engineer? The person that mobilized the drone?

- In which range of fires do you see a drone being deployed? Is it useful to deploy a drone for all types of fire?

In most situations a birds eye view is a good information gatherer for a situation with a lot of unknowns.

- Would transporting equipment be useful? Which equipment?

Probably not, because most of the equipment of the fire department is quite heavy and most of the time the ground vehicles can arrive at the location within 5-10 minutes. In most situations this time is short enough to save the situation and the people inside them. Having a single fire extinguisher or a fire blanket arrive 3 minutes earlier does not have a major impact. Maybe in the future.

- How much should a drone be able to carry?

The current drones weigh around 4.5 kg. Lightweighted sensors can be carried for the surveillance, but a useful amount of water for extinguishing fires by no means.

- What type of drone would be the most useful? A quadcopter, a fixed wing drone, or a hybridcopter (which is a combination of both)?

Fixed wing/hybridcopter is useful for surveying large fires, such as forest fires. This type of drones has not yet been implemented, but it would be a good addition to the tools available. The drones that are currently in use at the fire department are quadcopters, these drones provide a birds eye view with both an infrared camera and an optical camera.

- How can your drones be improved?

Longer batteries, better sensor package, stronger rotors, basically just standard technological improvement. The other thing is the previously mentioned fixed wing drones which can survey large areas and can stay in the air longer.

Medical department:

- How do you see drones be used by the medical personnel?

Mostly as an information gatherer, so the same as the eye in the sky concept the fire department stated. These types of drones will give a visual overview of the situation for the medical personnel so they wont get surprised by unexpected circumstances when they arrive.

- Would using drones to transport equipment between hospitals be useful? Equipment examples: Blood, vaccins, organs, antidotes or first-aid-kits

Helicopters are quite expensive to use. The cost of the vehicle, fuel and the education of a pilot is high. This creates a situation where only in very high demanding situations a helicopter is mobilized and not in all of the situations where the medical helicopter is required can it be mobilized. Transportation using drones is a nice mid-way solution between mobilizing a helicopter and a land vehicle. These drones can be instantly mobilized with small packages of whatever is necessary to whatever location.

- Would it be useful to transport an AED, organs, antidotes or a first-aid-kit using drones for an emergency call?

Transportation of AED's seem to be quite succesfull in populated areas, with enough volunteers that are able to use the equipment properly (ongoing research Göteborg, Sweden). However, for a cardiac arrest, the drone should be at the required location within 6 minutes for it to be of use. As a result, drones should already (constantly) be in the sky, at moment at which the emergency call is made, in order to be close enough already at that point.

- How much should a drone be able to carry?

Around 5kg. This should be enough to carry a sensor package, with an optical camera, an IR camera and maybe a large light. This light will make it easier for the medical personnel to work at night time.

- What type of drone would be the most useful? A quadcopter, a fixed wing drone, or a hybridcopter (which is a combination of both)?

Quadcopter: surveillance / eye in the sky. But sometimes not even this. Jaap Hatenboer argues that it will be more useful to have a fixed wing drone fly loops around the scene. This would make the drone more efficient in energy use and it will create a situation where the drone will have a view of the situation from a wide variety of angles. Fixed wing drone: Long distance flights between developed locations, such as hospitals or bloodbanks. Hybridcopter: Long distance deliveries to for example an emergency caller. It will be difficult for a drone to be useful when the situation is indoors. But the drone might be able to transport aids for the person in distress.

So, most drones can be of use in the medical department, it just depends on the situation. The quadcopter might be the most useless one, especially when technology is able to create a virtual recreation of the situation by having imagery from different angles. This will make a fixed wing drone flying a pattern above the situation more useful.

- How can your drones be improved?

Standard technological improvements like stated in the fire department section.

Society

There are different stakeholders to be considered for the influence of the society. The government is a major stakeholder, because of the legislation of drones for emergencies usage. Animal rights and environmental organizations have a large interest in maintaining and/or improving the current situation. The drone technology could be dangerous and do damage to society. The flying stakeholder who are using the airspace now must be taken into account, like bird, planes or other drones.

The effect on society would be beneficial on a great scale. (source with death due to cardiac arrest). When drones could deliver an AED within 6 minutes, the survival changes would increase significantly. Other medical usage could be the transport of blood or organs. Not only transport of equipment, but also for investigation for the fire and police departments. All of this would increase the safety and save precious time.

Enterprise

In order to realize emergency drones, the product needs to be produced by a technology company. This company will only build, deliver, and repair these drones. The company will work closely together with a government agency. This agency will be responsible for the usage and quality of the drones, after they have been bought from the drone company. A close cooperation between both stakeholders will lead to an better end product.

Whenever an accident happens due to a drone or due to the usage of an drone, this government agency can be hold responsible. The agency will have to test each drone thoroughly, to limit the risks of accidents. The government agency will also be ultimately responsible for the usage of data gathered by drones. The government agency will have to check at police, medical and fire departments how they deal with the information and data form the drones and if all drone deployment regulations are complied. The relation between the agency and the departments could be seen as principal-agent relationship.

When civilians have an unpleasant experience with the usage of drones by a police, medical or fire department or when they simply feel disturbed by the usage of drones in general, the government agency should be contacted. The agency should write a simply report about each of these complains. The agency should also have the tools to track down the specific drone and flightpath, to see if any regulations on drone deployment where infringed.

Use Cases

An use case for the medical department is with the company Zipline. Zipline is a California-based drone start-up that delivers medical supplies in Ghana and Rwanda. They want to deliver covid-19 vaccines throughout the country. The Nigeria’s state Kaduna allowed Zipline to deliver more than 1 million doses of other vaccines in Africa over the past year, also blood products, medications and other vaccines. When they want to deliver the covid-19 vaccines, they need to storage it at very cold temperatures. Zipline also wants to operate in the USA. https://www.cnbc.com/2021/02/04/role-of-medical-drones-in-global-covid-vaccine-campaign-is-growing.html

Legal requisites

From the interviews we realized that there was quite some difficulty with conflicting laws when using drones. In this section we will cover two areas where the usage of drones has been limited or adjusted. In each area we will explain how the laws are conflicting, how much the drone pilots should be allowed to do in order to execute their job unhindered and how the laws should change for this goal. The two areas that we will be covering are laws concerning privacy and aviation.

Privacy law

Aviation law

As of 31 December 2020, the European rules apply for drones. These rules are applied in all the counties in the European Union. There are three categories which depends on the risks; flights with a low risk level, flights with a medium risk level and flights with a high risk level. Each risk level has different rules and requirements. Low risk is under the open category, therefor no authorization or declaration by the operator is required. Medium risk is under the specific category, therefor a Specific Operations Risk Assessment, AESA authorisation and STS and predefined risk assessment EASA. High risk is under the certified category, therefor certified operator, certified UAS, licenced pilot and delegated regulations EU .
In the table below the different risk levels are stated with their rules and requirements .

The requirements

	Low risk	Medium risk
The requirements for drones	• The drone has to be less than 25kg • Maximum height of 120 meters • No transport of hazardous substances • Nothing may be dropped out of the drone • You must always have a visual on the drone	• It is allowed to fly above people • It is allowed to fly in the neighborhood of aerodromes • The drone may be above 25kg • The drone may fly above 120 meters • The drone may drop something • The drone may be out of sight
The requirements for drone pilots	• The age must be 16 years or older • Someone under the age of 16 years can fly if there is an observer with a pilot’s license • You must have your pilot’s license with you when you use your drone • You won’t fly in restricted areas • Not under influence of alcohol or drugs • You are not allowed to flight in the neighborhood of emergency services • You land your drone when other air traffic approaches • Respect other people’s privacy, so filming with permission	• The owner of the drone should be registered (by the RDW in the Netherlands) • The pilot should be licensed • The operator must do a risk analysis before flying with the drone • The operator must have a flight permit (of ILT in the Netherlands)

The rules and requirements for high risk drones are still in development. The EASA expect to have these rules by the second quartile of 2021.There are more rules and exceptions, like a toy drone with a maximum of 250 gram has no registration for the pilot and doesn’t have to do a knowledge test.
This picture gives a clear overview of the rules and requirements of the usage of drones which are stated in the table.

Drone rules

Below is a map of the flight regulations in the Netherlands.

Map of the no flight regulations
Red: no-fly zone
Blue circle: only flying with permission of the administrator
Pink: low flight area, only flying allowed when someone else is present
Green: Natura 2000 area which has a drone prohibition

The maximum height drones are allowed to fly in the Netherlands is 120 meters . This limitation is not limiting our users because drones can fly below this altitude without problem.

The maximum weight of drones we found was 25 kilograms, this was stated in these two documents 1 and 2.
BUT it is stated here that average risk drones are allowed to weigh more than 25 kilograms.??
25 kg max but not for average risk drones? https://www.rijksoverheid.nl/onderwerpen/drone/nieuwe-regels-drones

State of the Art

Transport drones

Medical drone service

Drone company AVY and several partners are currently testing a long range drone delivery service . The consortium, called Medical Drone Service, will research how the system can impact healthcare in the Netherlands. This consortium consists of several companies, that each have their own expertise; the most important ones are: The ANWB (who are also behind the medical helicopters), PostNL (postal logistics), Erasmus MC (hospital) and Sanquin (blood bank).

During this pilot, a distance of 15 km is travelled in a sparsely populated area, and in the current stadium no medical equipment is yet transported. The main transport is meant to consist out of e.g. medicines, blood and urgent medical deliveries .

The drone flies autonomously, but is constantly monitored and at any time the control can be taken over. This specific drone is the AVY Aera, which is also called a Vertical Take Off and Landing wing drone. This term, as you might expect, means that it can take off and land vertically, and subsequently fly horizontally. This can be of great advantage in crowded areas, as the vertical landing makes large landing strips redundant. The drone has a wingspan of 2.5 meters and flies with a speed between the 70 and 80 km/hour, which it can maintain for about an hour. The height it flies at is about 100 meters and at the moment it can only transport a maximum load of 1.5 kilograms. An example of a technical challenge that this drone faces is to maintain a certain temperature, as blood has for instance ideal temperatures at which it should be transported . In addition, it doesn’t fly at bad weather conditions.

Medical drone service's drone

Zipline drone network

Blood transport

The American drone company Zipline created the world’s first ever drone delivery network for blood transportation in Rwanda (Africa), in October 2016 . Zipline has distribution centers from where the drones are launched. These centers also perform the function of storage and warehousing of blood and the drones. When a doctor places an order for blood to the distribution center (e.g. through a message or call), workers at Zipline takes the blood from the refrigerator, wraps it with insulated paper and packs it in an insulated cardboard box, after which it is loaded in the drone. Subsequently, the drone takes off to deliver the cargo to one of the clinics.

Zipline uses planes instead of quad copters (which uses four rotors), as quad copters uses far more energy to fly. They can’t manage the range from batteries necessary to travel longer distances and are relatively slow as well. On an average, one delivery is completed in 15-45 minutes and it takes 5-7 minutes to launch the drone after receiving the order. Zipline handles approximately 500 deliveries per day. These drones travel with a speed of 100 km/hour, with a range of over 160 km (allowing the drone an 80 km zone around the location). When the drone reaches the delivery location, it descends to 30 feet to deliver the packet.

Zipline's plane-like drone

About the physical components of the drone. It has a wingspan of 3 meters and the maximum load it can handle per flight is 1.8 kilograms. The batteries (lithium ion batteries with a total capacity of 1.2 kilowatt hours) are the heaviest part of the aircraft, making up half of the total weight of the aircraft, weighing a total of 10 kilograms. The aircraft itself thus weighs about 20 kg.

The drone has a few specifics that are worth mentioning. Instead of a regular GPS circuit, a detachable battery is used in which a GPS is present. This was done as the regular one experienced delay when connecting to the satellite. Another point is the fact that the cargo is dropped with a little parachute. As a result, the clinic at which it is delivered does not require any additional infrastructure to land the drone, and the drone can immediately return to the distribution center. The landing system for the drone is impressive and complicated at the same time. At the distribution center, two actuated arms are located, between which a wire is strung. The drone flies towards the arms, which catch a hook attached to the drone, and brake and end the drone’s flight.

Takeoff Zipline's drone

Vaccine transport

The company Zipline, which is also behind the delivery drone network for blood discussed above, are starting this spring with delivering COVID-19 vaccines . This will be done in the regions in which they are already active, for example Rwanda, Ghana and Tanzania, but also rural parts of the U.S.

A big challenge presented by many of the vaccines, is their temperature requirement. The Pfizer vaccine for instance has to be stored at minus 70 degrees Celsius. To overcome this issue, Zipline will store vaccines in ultra-cold freezers at its distribution centers, and when a clinic needs vaccines, the drones can make a delivery within roughly half an hour. As a result it allows rural and remote health facilities to bypass the need for having the freezers themselves.

Surveillance/reconnaissance drones

Eye in the sky

On their website the West Midlands Police in the UK discuss the way drones can be used to assist officers in scanning large areas in a short amount of time . These areas being: crime scenes, hard to reach areas, major incidents or looking for missing persons. The drones cost between 2.000 and 10.000 pounds (2.320-11.600 euros). The drones are operated by specially qualified officers that have trained under the Civil Aviation Authority (CAA) regulations. The drones are used for a short 15 minute period of time to minimize noise concerns. The drones are allowed to fly up to 120 meters high. The smallest drone has a top speed of 65 km/h. The drones can fly within 500 meters of the pilot. They make use of a lithium-polymer battery that can be charged either in buildings or on police vehicles.

West Midlands Police Drone

The Fire Department of New York (FDNY) has been using tethered drones at incident scenes since March 2017. The HoverFly drones are equipped with video and infrared cameras. They are able to evaluate fire travel, structural issues like cracks in a building or danger of collapse, and roof operations to determine if anything is unsafe and needs corrective action. HoverFly drones have a constant power source and are able to give very clear pictures. The drones are operated by pilots that are part of a command tactical unit that is dispatched from the FDNY command center.

FDNY uses HoverFly drone

The Millstone Valley (NJ) Fire Department in Franklin Township Fire District No. 1 uses DJI drones . First they had an off-road search and rescue team that used Polaris Ranger utility terrain vehicles and a 4×4 brush truck but then they realized how practical a drone would be. In the first year of usage, they found multiple lost hikers using drones. Millstone Valley also has used its drones on special call from the New Jersey Forest Fire Service, for prescribed burns and uncontrolled wildfires. With the drones, they are able to determine where the fire is and to predict where it goes.

NJ use DJI drones

Design research

Drone requirements

Before we could make a start on the actual design of the drone, we first needed to know what the purpose of the drone is and for what department the drone will work. This was not completely clear until the interviews were done. From these interviews it was concluded that a drone single design could benefit the medical, police and fire department. In order to start the design phase, the most important tasks of each of the departments were listed. Since both police and fire department would have the same requirements for the drone, these departments were listed together in table??. The medical department had other requirements for a drone, so this department was listed in a separate column.

, they were placed together. The goal of the drones for the police and fire department is areal reconnaissance and the goal for the medical department is to carry small loads from A to B as fast as possible.

The importance of the specifications

	Police and fire department	Medical department	Source
Flight speed	Preferred to be high: drones can view the location from large distance and most of the time it will only be hovering in the air, however the drone will need to be on location quickly.	Needs to be high: to deliver the package as quickly to the location as possible and to compete with ground delivery
Flight endurance	Preferred to be high: reconnaissance missions can take long, however landing and recharging does not have to take a long time	Needs to be high: has to be able to make it to the location
Payload	Needs to be quite high: the sensory package can weigh upwards of 5 kilos	Needs to be high: blood and organs can be quite heavy in combination with all sensors required to fly
Stability	Needs to be stable: the camera can stabilize small disturbances but not all	Not required: the packages will be attached firmly to the drone frame

The correct drone type

We then had an idea on some requirements for each of the drones. We started looking at the state of the art of drones and what drones would fit the best for our cases. We looked at rotary drones, fixed wing drones and VTOL (Vertical Take-Off and Landing) fixed wing drones, these can be seen in the figure below from left to right.

From left to right; DJI matrice 600, Lockheed Martin Stalker, ALTI transition VTOL

Drone kinds

	Rotary	Fixed wing	VTOL fixed wing	Sources
Fly speed	60-80kph max	80kph + (highly depended on wing shape and size)	80kph + (highly depended on wing shape and size)
Flight endurance	30 min average	3-12hr	VTOL part +/-15min, Fixed wing part (2-12hr)
Payload	3-5kg (depends on drone size)	2-10kg (depends on size)	2-10kg (depends on size)
Stability	Good	Good	Good
Take off space	Not required	0-10m (depends on size and weight and take off system)	Not required
Landing space	Not required	0-30m (depends on size and weight and landing system)	Not required
Camera suitability	Very stable, even used in movie making	Good	Good

Recommendation

Based on the table above and all the typical specifications for each of the drone types For the police and fire department we recommend to use a VTOL fixed wing drone, it can hold a camera and has high flight time. Both of these factors are important key aspect to support the police and fire department. The medical department will also benefit from a fixed wing VTOL drone since has a high endurance and high fly speed. The drone is also able of taking off and landing anywhere, making it easy to fly from A to B.

Propellor

Regarding a desired flight velocity and energy consumption, the design of a drone’s propellor is of great importance. For a multirotor propellor there are a few key variables that need to be considered in the its design: The size, the pitch, the blade configuration and the material . These variables discussed here will mainly hold for rotary drones, but the general aerodynamics and energy consumption can be also be used for other drone types (e.g. fixed wing).

First of all, the size. The main difference between a small and large propellor is the power consumption and level of thrust. Larger propellors sweep more air and thus take more energy to get spinning. These will have more thrust and can fly more steadily. Smaller ones require less power and will be able to change altitude more rapidly. Just as important as these considerations, is the requirement of a well matched motor. If a small propellor is placed on a motor made for bigger sized propellors, it will lead to a too high RPM (Rotations Per Minute) with very little thrust. A typical diameter is around 8 to 9 inches .

The pitch of a propellor refers to the angle of each of the blades on the propeller. A high pitch will lead to more overall thrust and top speed, while a low pitch increases the response time and uses less power. A propellor with low pitch is only efficient at low speeds, while a high pitch is more suitable for flying in large open areas.

Different propellor pitches

The amount of blades on a propellor is referred to as the blade configuration. Increasing the amount of blades will not have that much of an effect as increasing the size. Many blades are more suitable when flying in places where making fast turns is a requirement, while less blades are when thrust is less critical. In general, tri-blade propellors provide the best balance between efficiency and thrust .

Finally, the material of the propellor, for which polycarbonate is a very common option, known for its good stiffness. Material choice depends also on the climate in which the drone is operating. In a hot climate for instance, glass fiber might be needed to reinforce the propellor, as other materials (e.g. polycarbonate) can become soft and thus less efficient.

Rotor

A rotor is the common name for the combination of a motor with a propellor. In general, multiple rotors are either symmetrically or co-linearly attached to a drone’s frame. There are a few key specifications for these motors. The operating voltage is typically 11.1 or 14.8 Volts, in combination with a three or four cell Li-Po battery. Another important variable is the amount of kilovolt of the motor, which is also indicated as the rotation speed per Volt. From this relation it becomes immediately clear that the propellor will spin faster at a higher kV (RPM/V) rating. However, it is important to keep the balance between the amount of kV and the size of the propellor. For instance, a too high kV combined with a too large propellor will require more torque and can subsequently generate too much heat or even overheating . The weight of one single rotor is usually between the 12 and 20 grams.

The table below provides an indication of several components of a drone (a quadcopter specifically here) relate to each other .

The relation between the rotor components of a quadcopter

Frame size	Prop size	Motor size	Energy
150mm or smaller	3" or smaller	1306 or smaller	3000KV or higher
180mm	4"	1806	2600KV
210mm	5"	2204-2206	between 2300KV and 2600KV
250mm	6"	2204-2208	between 2000KV and 2300KV
350mm	7"	2208	1600KV
340mm	8", 9", 10"	2212 or larger	1000KV or lower

For drones, two main types of motors are distinguished: Brushed and brushless . This distinction is based on the way of generating a magnetic field, which is done through permanent polarity for a brushed one and switching polarity (with a permanent magnet) for the brushless one. The brushed version is commonly used for very basic (consumer) drones, while the brushless one is often used in larger drones, as it has a wider speed range and longer lifespan.

With this knowledge and the info from the table can be concluded that a brushless motor should be used, in combination with a KV value that is not too high. Since the frame from the drone that is to be designed for this project will be near the 450 mm or even a bit more, the lower row of the table will be taken as reference, with the KV of 1000 or lower.

Power Source

Combustion engines

A drone will need a power source to power the propellers and generate lift. There are different ways of powering a drone. Most drones use batteries to power their electric components. The most batterie for powering a drone is a Lithium-ion (Li-ion) battery. Not every battery is meets the requirements for powering a drone. The battery needs to have a high discharge rate, high energy/weight ratio and a fuel gauge is essential for showing the user when a landing is required.

When drones get bigger, they generally have the ability to lift more weight. Especially in fixed wing and VTOL fixed wing drones, the market shows that when drones get larger in size the way of powering a drone changes. Since becomes bigger, the possibility of using an combustion powered engine opens up. These engines are able of powering the drone for long periods of, dependent on the size of the fuel tank. In 2017, MIT engineers build an gas powered fixed wing drone, that was able of staying in the air for 5 days. The engines used in these drones are usually one or two cylinder engines, weighing between 1.3 to 7.3kg and they have power outputs ranging from 1.6kW to 18.9kW .
A fixed wing drone will need one combustion engine to operate, however a VTOL fixed wing drone will also need additional batteries to supply power to the propellers performing the vertical take-off and landing. An endurance focused VTOL fixed wing drone can be called a ‘hybrid’, since it combines multiple energy sources. An example of such endurance focused drone is the ALTI Transition , this drone combines an electric and fuel power and is ably to fly up to 12 hours.

However, the drone that is to be designed in this project, does not have the requirement to fly for such a long time. As stated already above, there is a wide range of fuel motors that are used in UAVs . When looking into one of the smallest versions, a 32 cc , it becomes clear that these already can bring along some practical problems. For this one, the basic engine weight is already 1.3 kg, while in total with all components/accesoires it sums up to about 2.7 kg. In addition, it of course will need fuel to run, 93 octane to be precise. Such a fuel has a density in the range from 0.715-0.790 kg/L . On a long flight, e.g. 120 km, a minimum of about 5 kg of fuel will be required. Combining this with the engine’s weight, a total of 8 kg will be represented by this part of the drone alone.

This is especially high when comparing it to the weight of components for the current relevant drones, discussed in the section State of the Art. The weight of a Zipline drone’s battery for instance is about 10 kg, while a drone with a fuel motor (especially of this size) will need electric support as well, subsequently exceeding this value with a significant amount. Furthermore, on a societal note, with the rapid developing energy-transition in mind, the usage of fuel is also not likely to stay relevant and ‘acceptable’ for many years.

32 cc combustion engine

Battery packs

The battery pack used by the Zipline drone comes down to a total capacity of 1.2 kWh. Such a range should also be strived for the drone to be developed here, as a similar size and transport load will be used. Then there are two options: Either to use multiple, separate batteries (e.g. for each rotor one), or to implement one larger one, that is connected to all rotors via a circuit. The latter one seems to be the most space-efficient option, as these packs can be quite robust. Since the middle part of the drone will already contain some sort of bulge, the drone’s frame only has to be adjusted to the battery pack here, instead of at multiple spots (e.g. towards the sides/wings).

For non-consumer drones (the scope outside the hobbyists), the specific battery packs used are often not revealed or at least can not be found easily. Therefore, a reference battery pack will be used, the ‘Victron lithium accu’ , which also has a capacity of about 1.2 kWh. This one is not specifically created for the usage of drones. It weighs 4 kg more than the one Zipline uses, which makes a significant difference of 40 percent in weight. From this one can assume that the volume of the two packs will also differ with a similar percentage. Therefore, in the CAD model, the battery pack will be modelled with the dimensions of the Victron lithium scaled with a factor of 0.71, to make it more realistic.

Victron lithium battery pack 1.2 kWh

Cameras

In our interview with Robbert Nijs (see interviews) he mentioned the types of cameras that are currently used within his field. The drones that are used in the Netherlands are equipped with an optical camera (DJI Zenmuse Z30) and an infrared camera that also has an optical camera inside of it (DJI Zenmuse XT2), so it can produce a video with both optical and infrared footage that are overlapped.

Material

An important preference of any aerial vehicle is to be as lightweight as possible . With this main preference in mind, there are several other material aspects that are important for a certain vehicle. Airplanes for example use aluminum because of it being lightweight, yet strong, allowing the plane to carry more weight or become more fuel efficient. Another material that excels at being strong, yet lightweight, is carbon fiber composite. It has a density of 1.7 g/cm³. Because of this low density, the drone will be able to stay in the air longer due to decreased fuel usage over time. Furthermore, carbon fiber composites are age resistant and thus require no needless upkeep.

Insulation

To provide a proper transport possibility, the transport cabin's material should meet the conditions of the to be transported goods. For the medical department, a variety of things could be transported, among which for instance blood bags (or samples) and organs. For both of these, preservation will only be feasible when it lies in a certain temperature range. For whole blood (standard donated blood) and red cells, this range is between +2 and +6 degrees Celsius . For most organs, the temperature should be slightly higher, as 4 to 8 degrees Celsius is the standard range for these .

When the drone is to be travelling long distances, e.g. between hospitals, it should be able to meet such temperature demands for quite some consecutive amount of time. This could reach up to a maximum of about 1,5 hours. Therefore, it is important that there is a cooling option provided for such a time range, while also meeting the temperature range of the transported item. One option could be to use a built-in refrigerator, of which the temperature can be specifically adjusted. However, such a system would result in a significant weight increase of the drone, while also increasing the amount of battery capacity (for both compensating the extra weight, as well as the refrigerator's power usage). Therefore, it is more obvious to go fore a cooling system that is more weight and energy efficient here: Insulation.

The insulation method that will be used here, is inspired by the well-known insulated water bottle. Such a bottle has the ability to keep a substance in a certain temperature range for a few hours in a row. This is enabled by the fact that the main bottle actually consists out of an 'inner' and 'outer' bottle. In between these two, instead of air, a vacuum is present . As a result, heat is much less capable to be transferred from both the inside to the ouside, as well as the other way around. This principle can thus also be applied on the drone. Depending on the flight duration and the specific required temperature for the transported item, it could additionally also be combined with a cooling element for instance. The majority of the current insulated bottles are made from stainless steel (RVS in Dutch), which are known to be good insulators and to be fitting well for such applications .

Design

Reference components

In order to make the CAD model and corresponding simulations realistic, a list of reference components will be used. These components give an indication of the properties of the most relevant equipment and parts. It should be noted that these components are thus mainly used to visualize the concept of the emergency drone, rather than to be stated in a detailed interconnected network, such as a system's blueprint would be.

The relation between the rotor components of a quadcopter

Component	Type	Amount	Dimensions	Weight	Source	Section
Infrared camera	DJI Zenmuse XT2	1	25 x 25 x 25 cm	629 g	Link	Cameras
Small propellor	2 blades, PC	4	22 x 2.6 x 0.34 cm	1.12 g/cm3	-	Propelllor
Big propellor	4 blades, PC	1	22 x 22 x 0.34 cm	1.12 g/cm3	-	Propelllor
Small rotor	Brushless Rotor Motor 1000KV	4	Length: 3.2 cm Diameter: 2.77 cm	58 g	Link	Rotor
Big rotor	EZRun SL 56113-800KV brushless motor	1	Length: 11.3 cm Diameter: 5.6 cm	174 g	Link	Rotor
Battery	Victron lithium battery 12.8V/100Ah	1	Original 19.7 x 15.2 x 32.1 cm Scaled with 5/7 14.1 x 10.9x 22.9 cm	Original 14.01 kg Scaled with 5/7 10 kg	Link	Battery packs
Body material	Carbon fiber-composites	-		1.7 g/cm3	-	Material
Insulation transport	Stainless steel (RVS)	-		7.93 g/cm3	-	Insulation

Sketches

First a sketch on paper was made, afterwards we proceeded with this sketch in CAD software.

First sketch, general layout of the drone

Dimensions

For the dimensions, other VTOL fixed wing drones where considered [2] [5] [6]. It is important that the drone is big enough to carry a payload of a +/- 3 kilos. In order to carry this weight a wingspan of +/-3.5m is chosen.

CAD

Not all individual parts have been added yet, as the focus has been on putting together the drone model as a whole. This will be done in the upcoming days.

Wing

We already made a start on the CAD design this week. However the progress was not that great. We were al not very familiar with the Siemens function required to make a wing, howerever after some struggles we figured it out. We also discussed the amount of detail that we want to put into the CAD model, and it was decided that the main focus will be on the main body of the drone.

The first wing

The first wing

Tail

Tail VTOL drone

Propellers

Two types of propellers are needed for our drone: the four propellers for vertical takeoff and landing and the one propeller that actually propels the drone once it is flying horizontally.

VTOL propeller

Horizontal propeller

Rotors

Large and small rotor

Frame big propellor

Frame big propellor

VTOL frame

VTOL frame

Camera

This model is a representation of the DJI Zenmuse XT2

DJI Zenmuse XT2 camera

Battery cabin

Battery pack cabin (lid opened)

Transport cabin

Transport cabin (lid opened)

Landing gear

Landing gear folded in

Landing gear folded out

Full assembly

After all individual parts were designed, an assembly was created. Within this assembly all parts were constrained to their correct location. The result can be seen in the figures??. As can be seen in the figures has the main servo with propellor be placed on top of the drone. This design choice has been made since their is not enough space in the main body for this servo, this design choice also positively influences the weight distribution of the drone. A similar drone design can be seen in a zipline drone to supply Rwandan villages [13].

The drone is also equipped with landing gear. This is an essential part of the drone since it will protect the drone camera from touching the ground during landing and take off. The idea is that the landing gear can be folded in when flying. However due to limitation in time, this has not been fully designed into the model.

In the middle of the drone, the battery will be placed. It is essential that the battery is being placed in the middle of the drone, since the battery is relatively heavy (10kg) and the weight needs to be distributed equally of the drone frame. The battery can be recharged after a flight, by opening the lid on top of the battery. The battery is not able to move inside the drone itself, it will be held in place by a lightweight frame, to deliver a stable drone flight. After finishing all parts, the drone was assembled and constrained.

The final drone design

Front View

Back View

Top View

Bottom View

Side View

Side View with folded out landing gear

FEM Analysis

In order to model the consequences of loads on our drone, FEM analyses were performed. Simcenter was used to optimize the drone's structural characteristics. Two FEM analyses were performed: One of the drone taking of vertically and one of the drone while it is flying horizontally. The 2014 aluminum alloy was used as material property for the entire drone.

Vertical take-off

For modeling the loads in the VTOL setting of the drone, the following constraints were used: displacement in the z-direction was free, rotations in all directions was free and displacement in the x and y directions were fixed. The loads that were modelled are gravity and an upwards force for each propeller, thus making 5 loads in total. Below all views of the reaction forces of the drone can be seen. These reaction forces mainly result from surface interaction and adhesion during sliding.

Reaction forces isometric view

Reaction forces left view

Reaction forces right view

Reaction forces front view

Reaction forces rear view

Reaction forces bottom view

Reaction forces top view

Horizontal flight

Reaction forces isometric view

Reaction forces left view

Reaction forces right view

Reaction forces front view

Reaction forces rear view

Reaction forces bottom view

Reaction forces top view

Planning milestones

In the figure below a planning of the project can be seen.

The planning for the project.

Workload

Here an overview is given of what everyone has done per week.

Week 1

Name	Student ID	Hours worked	Tasks done
Pepijn Hundepool	1427520	9	Intro videos + conference (1h), First meeting (1.5h), Meeting to choose subject's direction (1.5h), Studied and wrote summaries for papers (5h): See Summaries
Lucas Commissaris	1451065	10	Intro videos + conference (1h), First meeting (1.5h), Meeting to choose subject's direction (1.5h), Studied and wrote summaries for papers (6h): See Summaries
Sven Passier	1448781	9.5	Intro videos + conference (1h), First meeting (1.5h), Meeting to choose subject's direction (1.5h), Studied and wrote summaries for papers (5.5h): See Summaries
Bram van den Buijs	1464647		Intro videos + conference (1h), First meeting (1.5h), Meeting to choose subject's direction (1.5h), Studied and wrote summaries for papers: See Summaries
Stijn Borgers	1495968	9	Intro videos + conference (1h), First meeting (1.5h), Meeting to choose subject's direction (1.5h), Studied and wrote summaries for papers (5h): See Summaries

Week 2

Name	Student ID	Hours worked	Tasks done
Pepijn Hundepool	1427520	8,5	Tutor feedback meeting (0,5h), Meeting with the group for setting up user needs (3h), Coming up with questions (2h), Another meeting with the group for setting up survey (3h)
Lucas Commissaris	1451065	8,5	Tutor feedback meeting (0,5h), Meeting with the group for setting up user needs (3h), Coming up with questions (2h), Another meeting with the group for setting up survey (3h)
Sven Passier	1448781	8	Tutor feedback meeting (0,5h), Meeting with the group for setting up user needs (3h), Coming up with questions (1.5h), Another meeting with the group for setting up survey (3h)
Bram van den Buijs	1464647	?	Tutor feedback meeting (0,5h), Meeting with the group for setting up user needs (3h)...
Stijn Borgers	1495968	8	Tutor feedback meeting (0,5h), Meeting with the group for setting up user needs (3h), Coming up with questions (1.5h), Another meeting with the group for setting up survey (3h)

Week 3

Name	Student ID	Hours worked	Tasks done
Pepijn Hundepool	1427520	7	Tutor feedback meeting (0,5h), Setup technical specifications of a firefighting drone (1.5h), Group meetings (3h), Editing planning and wiki (2h)
Lucas Commissaris	1451065	12,5	Tutor feedback meeting (0,5h), Looking for contact information of the respective departments (2h), Finishing up survey and sending it (3,5h), Group meetings (3h), Problem statement and objectives (3,5h)
Sven Passier	1448781	7	Tutor feedback meeting (0,5h), Setup technical specifications of a police drone (1.5h), Group meetings (3h), Writing about Enterprise on wiki (2hr)
Bram van den Buijs	1464647		Tutor feedback meeting (0,5h), Setup technical specifications of a medical drone (...h), Group meetings (3h)
Stijn Borgers	1495968	9	Tutor feedback meeting (0,5h), Making survey and help sending it (5h), Wiki: questionnaire and adding consent form to appendix (0.5h), Group meetings (3h)

Week 4

Name	Student ID	Hours worked	Tasks done
Pepijn Hundepool	1427520	9	Tutor feedback meeting (0,5h), Group meeting (0,5h), Research reconnaissance/surveillance drones for State of the Art (5h), Group meeting on finalizing survey (2h), Edit wiki page State of the Art (1h), put it in main page for now
Lucas Commissaris	1451065	11,5	Tutor feedback meeting (0,5h), Group meeting (0,5h), Research transport drones for State of the Art (3,5h), Create and edit wiki page State of the Art, put it in main page for now (1h), Group meeting on finalizing survey (2h), Design research on propellers and rotors (3,5h), Editing wiki (0,5h)
Sven Passier	1448781	9	Tutor feedback meeting (0,5h), Group meeting (0,5h), Starting on drone design, requirements and types of drones (3.5h), Group meeting on finalizing survey (2h), Design research to power sources (2hr), Editing wiki (0.5h)
Bram van den Buijs	1464647		Tutor feedback meeting (0,5h), Group meeting (0,5h)
Stijn Borgers	1495968	7	Tutor feedback meeting (0,5h), Wiki: finishing questionnaire, adding interview and editing overall layout (3h), Group meeting (0,5h), Research on privacy regulations (3h)

Week 5

Name	Student ID	Hours worked	Tasks done
Pepijn Hundepool	1427520	10	Tutor feedback meeting (0,5h), Group meeting (0,5h), Interview with Mark Bokdam and debriefing (1h), doing Simcenter Fem and motion tutorials (4h), Group meeting (1h), Design meeting with Sven and Lucas (1h), researching drone cameras and materials (2h)
Lucas Commissaris	1451065	13,5	Tutor feedback meeting (0,5h), Group meeting (0,5h), Interview with Jaap Hatenboer and debriefing (1h), Interview with Mark Bokdam and debriefing (1h), Interview with Robbert Nijs and debriefing (1h), Research on Simulink drone (imported NX model) control (3h), Group meeting (1h), Design meeting with Sven and Pepijn (1h), Design research on engines, battery packs and rotors (4h), Editing wiki and adding deliverables (0,5h)
Sven Passier	1448781	11	Tutor feedback meeting (0,5h), Group meeting (0,5h), Interview with Jaap Hatenboer and debriefing (1h), Interview with Mark Bokdam and debriefing (1h), Interview with Robbert Nijs and debriefing (1h), Working on first wing in CAD (3.5h), Group meeting (1h), Design meeting with Lucas and Pepijn (1h), Working on general design and dimensions (1.5h)
Bram van den Buijs	1464647
Stijn Borgers	1495968	13	Tutor feedback meeting (0,5h), Group meeting (0,5h), Interview with Jaap Hatenboer and debriefing (1h), Interview with Robbert Nijs and debriefing (1h), Group meeting (1h). Summarizing and reformulating user sampling (5h). Adding sources from all sections (4h)

Week 6

Name	Student ID	Hours worked	Tasks done
Pepijn Hundepool	1427520	14	Tutor feedback meeting (0,5h), Interview Mirjam Meerkerk (0.5h), Group meeting (0,5h), Meetings with Sven and Lucas to discuss model's approach and progress (2h), Making VTOL and horizontal propellers (4h), Meeting with Sven and Lucas to assemble all parts (2,5h), Meeting with Lucas to finish and assemble all parts (4h)
Lucas Commissaris	1451065	19,5	Tutor feedback meeting (0,5h), Group meeting (0,5h), Meetings with Sven and Pepijn to discuss model's approach and progress (2h), Meeting with Sven to start on drone's frame (2h), Working on tail, frame big propellor, camera and rotors (3,5h), meeting with Pepijn and Sven to assemble all parts (2,5h), Scaling propellors and constraining them to their frame (2h), Meeting with Pepijn to finish and assemble all parts (4h), Constraining the propellors, wings, VTOL frames and editing Wiki (2,5h)
Sven Passier	1448781	16	Tutor feedback meeting (0,5h), Group meeting (0,5h), Meetings with Lucas and Pepijn to discuss model's approach and progress (2h), Meeting with Lucas to start on drone's frame (2h), Working on drone body (3.5h), Meeting with group to discuss progress (1h), Working on back body part and trying to make it hollow (2h), Meeting with Pepijn and Lucas to assemble all parts (2,5h).
Bram van den Buijs	1464647
Stijn Borgers	1495968	15	Tutor feedback meeting (0,5h), Interview Mirjam Meerkerk (0.5h), Group meeting (0,5h), Beginning with a script for the video (1h), Wiki: incorporating feedback & final interview (4h), Adding sources (2h), Researching coding (for tables and links, see next two tasks) (2h), Adding links for navigating this document (0.5h), Converting photos of tables to tables and improving them (4h), Editing new section: laws (1h),

Week 7

Name	Student ID	Hours worked	Tasks done
Pepijn Hundepool	1427520	13	Tutor feedback meeting (0,5h), Group meeting (0,5h), Performing multiple FEM analyses on the entire drone assembly (11h), Group meeting (1h)
Lucas Commissaris	1451065	18,5	Tutor feedback meeting (0,5h), Group meeting (0,5h), Meeting with Sven to look into landing options (1h), Create unfoldable landing gear (0,5h), NX motion try-outs (4,5h), Changing and adding figures CAD (1h), Writing insulation section (2h), Extending reference components table (1h), Editing Wiki (0,5h), Group meeting (1h), Simulation propellors and landing gear NX motion (6h)
Sven Passier	1448781		Tutor feedback meeting (0,5h), Group meeting (0,5h), Meeting with Lucas to look into landing options (1h), Group meeting (1h)
Bram van den Buijs	1464647		Tutor feedback meeting (0,5h), Group meeting (0,5h), Group meeting (1h), Meeting with Stijn to look into Aviation laws (1h)
Stijn Borgers	1495968		Tutor feedback meeting (0,5h), Group meeting (0,5h), Group meeting (1h), Meeting with Bram to look into Aviation laws (1h)

Week 8

Name	Student ID	Hours worked	Tasks done
Pepijn Hundepool	1427520
Lucas Commissaris	1451065
Sven Passier	1448781
Bram van den Buijs	1464647
Stijn Borgers	1495968

Appendix

This contains supplementary material for the text.

A. Summaries 25 sources

The 25 summaries of sources that were required in week 1 can be found on this separate page: Summaries.

B. Consent Form

Information form for participants

This study is performed by Sven Passier, Pepijn Hundepool, Bram van den Buijs, Lucas Commissaris and Stijn Borgers students under the supervision of Elena Torta of the Control System Technology group at Eindhoven University of Technology.

Before participating, you should understand the procedure followed in this study, and give your informed consent for voluntary participation. Please read this page carefully.

About this study

The goal of this study is to examine what the requirements of (insert user) would be for a drone that could assist them in an emergency situation. You are asked to fill in the survey with questions about the functions of such a drone.

This study will take less than 5 minutes to complete and does not involve any risks.

Voluntary Participation

Your participation is completely voluntary. You can stop participation at any time. You can also withdraw your permission to use your data up to after completing this survey.

Confidentiality and use, storage, and sharing of data

This study has been approved by Elena Torta, teacher of the bachelor course Robots Everywhere of Eindhoven University of Technology. In this study experimental data will be stored. The anonymized dataset that, to the best of our knowledge and ability will not contain information that can identify you, will be used in this research and stored on a TU/e OneDrive account.

Further information

If you want more information about this study, the study design, or the results, you can contact Stijn Borgers (contact email: s.borgers@student.tue.nl). You can report irregularities related to scientific integrity to confidential advisors of the TU/e, whose contact information can be found on www.tue.nl.

Certificate of consent

By starting this study, I indicate that I have read and understood the study procedure, and I agree to voluntarily participate.

C. Questionnaire results

To go back to the questionnaire section click here

Below the questions and results of the fire department survey can be seen.

The results of the fire department survey

Below the questions and results of the medical personnel survey can be seen.

The results of the medical personnel survey

References