A First Course in Aerial Robots and Drones

Yasmina Bestaoui Sebbane

• Publisher: Chapman and Hall/CRC
• Year: 2022
• ISBN:
  9781000543087
• Edition: 1
• Topic: Informatica
• Subtopic: Intelligenza artificiale (IA) e semantica

A First Course in Aerial Robots and Drones provides an accessible and student friendly introduction to aerial robots and drones. Drones figure prominently as opportunities for students to learn various aspects of aerospace engineering and design. Drones offer an enticing entry point for STEM studies. As the use of drones in STEM studies grows, there is an emerging generation of drone pilots who are not just good at flying, but experts in specific niches, such as mapping or thermography.

Key Features:

• Focuses on algorithms that are currently used to solve diverse problems.
• Enables students to solve problems and improve their science skills.
• Introduces difficult concepts with simple, accessible examples.

Suitable for undergraduate students, this textbook provides students and other readers with methods for solving problems and improving their science skills.

CHAPTER 1Introduction

DOI: 10.1201/​9781003121787-1

1.1 INTRODUCTION

This book prepares readers to the field of unmanned aircraft systems (UAS), also known as remotely piloted aircraft systems (RPAS) or drones. The term unmanned aircraft includes very large aircraft similar in size and complexity to manned aircraft, but also very small drones. The smaller ones have the size of an insect. Even small UAS may be equipped with advanced features that allow the drone operator to operate out of their visual line of sight (VLOSVisual line of sight), relying on the guidance and navigation control system of the drones. The UAV performance capabilities coupled with the installation of cameras and other sensors make small UAVs very attractive for both commercial and not commercial operations. The remote pilot keeps the UAV close enough to be capable of seeing it with vision unaided by any device other than corrective lenses, and seeing and avoiding all threats and hazards. Drones can hover or reach a speed of more than 1000 Km/h, be controlled by a computer, a smartphone, a tablet or satellite communication, and carry all kinds of material.

The civil operation of UAS is a rapidly growing area of aviation as technical developments are booming. New actors compared to those of manned aviation are appearing and different uses be commercial or leisure are being found. UAVs mostly perform services and tasks considered by humans as dull, dirty or dangerous. Drones that can fly closer to the ground than manned aircraft are considered well-suited for risky flights to accident areas. During the hurricane season in the US of 2017, drones came to the rescue in many different locations and scenarios. Drones were used to identify the location of hurricane survivors that needed to be rescued, to assess damage, to evaluate routes toward saving those caught up in flood conditions, and to collect vital information on the status of places that would otherwise be impossible to reach. They can help in fire-fighting, survey of flooded areas or areas affected by chemical, biological or nuclear accidents, help in various domains of science research, and also finding missing persons.

Drone applications in agriculture are booming, and new agriculture focused drone companies and products are being announced all the time. UAVs allow farmers to collect more actionable data about their crops. Also, new data-focused platforms are helping to analyze and use the data gathered to better pinpoint crop damage. By helping to create detailed maps, aerial robots UAV can assist in detecting illegal logging operations, as well as tracking and monitoring overall tree count and the health of a forest. Using Normalized Difference Vegetation Index (NDVI) imagery, areas of dry vegetation can be monitored, which can assist with forest fire prevention. NDVI quantifies vegetation by measuring the difference between near-infrared (which vegetation strongly reflects) and red light (which vegetation absorbs). Maps can also help identify dead trees, revealing whether a disease might be affecting the forest.

UAVs can also provide commercial services, such as delivery of packages, infrastructure maintenance and monitoring, aerial mapping, and so on. For example, as drones become cheaper, they are becoming a viable tool for countries with fewer resources to use for mapping projects. The Zanzibar mapping initiative has the goal of creating a high resolution map of the islands of Zanzibar and Pemba, covering an area of over 2,000 square kilometers, by using low-cost drones instead of satellite images or manned planes. Zipline announced a partnership with the government of Rwanda to deliver blood and other crucial medical supplies to rural areas that are difficult to reach by land. Drones are helping archaeologists to create detailed 3D maps of important sites so that even if they do fade with time, an accurate replica will persist that can be studied and used as a resource for future generations. As time passes, archaeological sites can become degraded and even fall into danger of disappearing beyond recognition.

Drones can also provide complete coverage of telecommunications and help authorities in security. For example, the FAAFederal aviation administration has officially approved the use of drones to restore cell service in Puerto Rico, following the devastation brought by Hurricane Maria. The Sea Shepherd Conservation Society has been using drones to help in stopping poachers on the open oceans. Police Departments around the world are starting to incorporate drones into their operations. Police officers are using drones to help assess damage following floods, fires, and other natural disasters; to create detailed orthomosaic maps of crime scenes, and even of places where a crime might be likely to happen so that they can use that knowledge to respond more quickly to potential threats; for accident reconstruction; and for fugitive apprehension, among others. Using aerial thermography, a drone can fly over the sight of a fire that is almost out to identify smoldering hot spots that might not be visible to the naked eye. Aerial thermography can also help to quickly find potential fire victims who need immediate medical attention in fires that are still smoldering.

UAVs are an option of inspection that continues to improve with collision avoidance possibility, higher levels of autonomy, higher payloads and alternative imaging sensors. Time is crucial in search and rescue scenarios. If someone is lost in the woods in harsh conditions, the chances of survival all come down to how long they are out there before someone finds them. Drones help search and rescue teams find people quickly using aerial thermography to identify heat signatures. Drones can also be helpful for getting an aerial view of an area where a search and rescue mission needs to take place in order to help guide the work being done by people on the ground. In Canada, a search and rescue team found a group of five missing snowboarders and skiers that had been missing for two days using UAVs with infrared cameras.

Some advantages of UAVs over conventional manned aircraft include:

1. It is programmable such that the UAV does not exceed its limits. The on-board computer uses the information given by the sensors and can calculate the limits of the aircraft. Thus the UAV will not undertake a maneuver that will cause it to stall.
2. Drones tolerate wider environmental ranges, greater ranges of pressure, temperature, and turbulence.
3. UAVs are also able to operate in areas that would prove hostile to humans, such as Nuclear, Biological, or Chemical (NBC) radiated areas.
4. UAVs save weight as there is no pilot and no-pilot related equipment on-board.
5. UAVs have lower operational costs. The reduction in weight and size allows the vehicles to operate on far less power.

Remark 1 UAVs generally possess shorter flight endurance than manned aircraft which limits their overall operations and work area.

Fundamental safety requirements are the same for manned or unmanned aviation. The basic principles are:

1. UAVs should be as safe as manned aviation;
2. UAVs operations should not exclude other airspace users;
3. UAVs should adapt to Air traffic management (ATM) and to existing regulations. UAVs should be transparent to Air traffic control (ATCAir traffic control) and to other airspace users;

Definition 2 Air traffic management (ATM) consists primarily of air traffic control ensuring that aircraft are safely separated in the sky and at airports), air traffic flow management (sending flight paths to a central repository, analyzing and computing them) and aeronautical information services (compilation and distribution of aeronautical information needed by airspace users). Air traffic control (ATC) is responsible for providing the safe, orderly and expeditious flow of air traffic at airports where the type of operations and/or volume of traffic requires such a service.

The current chapter begins by introducing common UAV categories, and then it describes some current regulations.

1.2 UAV CATEGORIES

An Unmanned Aircraft System (UAS) includes an unmanned aircraft, the human element (UAV operator, payload operator, flight technician, etc.), payload, control elements (autopilot and ground control stations) and data link communication (line-of-sight, satellite).

Definition 3 Remote pilot or operator person who is in control of the flight part of the aircraft.

UAVs can be remotely controlled or fly autonomously based on pre-programmed flight plans or more complex dynamic automation systems. Unmanned does not imply fully autonomous flight.

Definition 4 The payload is the equipment a UAV carries during the flight that is necessary to accomplish the mission. There are various types of payloads that are mounted according to the mission type. They describe the capability of the airframe structure to resist expected flight loads and provide test data/ or analysis. External load operations are allowed if the object being carried by the UAS is securely attached and does not adversely affect the flight characteristics or controllability of the aircraft.

For classification according to size, the following sub-classes can be presented: Micro or Nano UAVs, Mini UAVs, Very small UAVs, Small UAVs, Medium UAVs, Large UAVs. UAVs also can be classified according to the ranges they can travel and their endurance in the air using the following sub-classes: Very low close range UAVs, Close range UAVs, Short Range UAVs, Mid-range UAVs, Endurance UAVs.

Definition 5 Unmanned aerial vehicle (UAV) aircraft with no on-board pilot, from a few grams to hundreds of kilograms. The term drone is more common for military use, whereas UAV or aerial robot is more common in universities.

They also be of different types: fixed wing-airplane; lighter than air-airship; rotary wing-helicopter or quadcopter (quadrotor); Bird or insect-like.

Definition 6 the lift is the carrier effect of the combined actions of the pressures and depressions that the air exerts on a body. Pressure is the application of a force on a surface.

A rotor craft is heavier than aircraft that depends principally for its support in flight on the lift generated by its rotors. The lift of the fixed-wing type is created mainly by the wings. Lighter than air drones rely on low-density gas inside the envelope to balance its own weight and the weight of the payload. It uses buoyancy to float in the air. Flapping wings drones fly like birds, and they mimic avian flight. They are expected to better navigate in rugged, unpredictable environments. They seem to be more efficient and wind-tolerant than inert wings.

Remark 7 Among the various types of UAS, the one with highest units worldwide is the rotor-craft or rotary-wing type followed by the fixed-wing category. Fixed-wing UAVs are able to carry more equipment on less power. These features determine that fixed-wing UAVs suit perfectly long missions. However, airplanes are not the best option to perform a precision mission. Due to the air moving over their wings to generate lift, they cannot hover in one spot and, as a result, cannot provide the precise camera positioning, while rotary-wings vehicles can do this perfectly.

The ongoing improvement of cost-effective multirotors symbolizes game-changing technological breakthrough. Even though drones seem at first look to be an easy application of simple physics—air gets pushed down, craft gets pushed up—in fact, they represent an intersection of numerous advancements in electronic miniaturization, applied computing, robotics, imaging and satellite navigation.

UAVs being susceptible to weather conditions, the remote pilot should use accurate and timely weather information to make informed decisions, to plan and execute effective fuel management, diversions and alternate route planning. Many UAVs often fly at lower altitudes, causing them to be directly affected by the weather. The UAVs can be more sensitive to wind or precipitation than large aircraft, but they may also be able to adapt to the weather changes with more agility due to their lower operating altitudes. Information on wind speed and direction, cloud ceiling, visibility, precipitation, humidity and temperature is crucial for flight plan preparation and execution. Visibility is the greatest horizontal distance at which prominent objects can be viewed with the naked eye. The remote pilot must be able to see the UAV at all times during flight.

Even small UAS may be equipped with advanced features that allow the user to operate the UAS out of their VLOS (visual line of sight), relying on the guidance and navigation control system of the unmanned aircraft, which usually provides self-stabilization and some automated functions. Navigation determines the location of the UAV, then allows the UAV to navigate ...