Introduction to Drones

Drones have been become one of the hottest tech toys in recent years, but what are these flying machines and what are they capable of?

Definitions

The word “drone” got its origins from an old English word drān, which referred to a male bee whose job is to mate with the queen bee or a monotonous sustained sound.  

When we think of drones, we think of a missile or a remote-controlled pilotless aircraft, a surveillance tool meant to keep watch over a place or an innovation developed for delivering products.

One of the most common definitions for drone is an unmanned aircraft or ship that can navigate autonomously, without human control or beyond the line of sight.

History

Types of Drones

There are 3 major types of drones which have different characteristics to cater to different need

1. Multi Rotor Drones

Multi rotor drones are most commonly used for photography and videography.

This can be further classified by the number of rotors: tricopters have three rotors, quadcopters, have four and hexacopter and octocopter have 6 and 8 rotors respectively. 

Multi rotor drones typically have a limited flying time of only 20 to 30 minutes because most of the drone’s energy is used to power each rotor to help it stay balanced. Thus, energy efficiency increases as the number of rotors decrease.

Multi rotor drones are beginner friendly because they require minimal skill and are usually the cheapest and easiest to manufacture. Multi rotor drones can only operate on electric motors due to their fast and high precision throttle changes that gas engines have difficulty supporting.

2. Fixed Wing Drones

Fixed wing drones have wings instead of rotors to provide lift. Because of this, they only need energy to propel them forward and are more energy efficient than multi rotor drones. 

Gas engines can be used to power fixed wing drones which can allow them to fly for longer periods of time.

Despite these pros, fixed wing drones are not equipped to carry cameras so they can not be used for photography; they also require more skill to successfully launch and land. 

The average pricing of fixed wing drones tend to be higher than multi rotor drones, so the required skills and pricing make fixed wing drones less accessible to beginner.

3. Single Rotor Drone

Single rotor drones are very strong and look similar in structure and design to actual helicopters

Despite its name, single rotor helicopters actually have 2 rotors. There is one large rotor at the top of the helicopter for lift and one small rotor at the back for controlling direction. 

They have one big rotor like a big spinning wing and a small sized rotor on the tail for direction and stability. In case if you have a mixture of hover possessing heavy loads but need a faster flight time with longer endurance then single rotor type helicopters can be the best choice for you.

How They Work?

With a joystick and a GPS system, the operations of most consumer drones seem no more complex than playing a video game.

However, behind the easy user interface are an accelerometer, a gyroscope, and other complex technologies working to make the mechanics of drone flight as smooth as possible.

1. Main Controller (MC)

The heart of the flight-control system, this can be thought of as the “brains” of the UAV. It is an embedded computer (many run Linux) that has custom software for controlling the aircraft, sometimes user-reprogrammable through a software development kit (SDK). 

In some designs, the MC is a separate module with connection ports. On others, especially consumer products, there may be a single circuit board (PCB) that includes the MC, gyros/sensors, electronic speed controllers (ESCs), and other core flight electronics.

2. Gyros/Sensors

For autonomy to work, the MC needs to track how the aircraft is flying. To accomplish this, some form of sensor array is provided.

Generally, it will include accelerometers, inertial measurement units (IMUs), and gyros, and may also work in conjunction with positional data from an optical flow system or GPS/compass.

Basically, these sensors tell the UAV how fast its acceleration is changing, in what direction, and whether it is right-side up.

Those familiar with motorized gimbal camera stabilizers may recognize the same sensor technology being employed here as in gimbals.

3. Electronic Speed Controllers (ESCs)

HUBSAN ESC for H501S X4 FPV Quadcopter

Each motor has an ESC (though some designs put all on one board).

Electronic Speed Controllers (ESCs) translate the signal to the electrical supply, controlling the rotational speed of the motor by adjusting electric current (Amp) to ensure the motors run smoothly and efficiently.

With six or more rotors, active feedback makes it possible to keep flying (enough to land safety) if one motor fails.

4. Receiver

Spektrum AR400 4-Channel DSMX RC Aircraft Receiver

This receiver is for the radio control system. It pairs (“binds”) with the controller the pilot or operator holds, which logically, if confusingly, is known as the “transmitter.”

Receiver doesn’t just receive signals from the drone controller. It also interprets the signals and converts them into alternating current pulses.

This information is then sent to the flight control board, or flight controller, which puts the information into action by controlling the drone as indicated by the original radio signals.

5. Motors

3DR Motor Pod for Solo Quadcopter

Motors are usually paired, each pair a set containing one clockwise (CW) motor partnered with one counterclockwise (CCW) rotating motor, though they may be sold individually.

Motors provide the spinning motion to the propellers which allows them to “push” off the ground and provide lift.

Aside from providing lift, drones also rely on the propellers for directional movement. By varying the rate of rotation of each propeller, drones achieve a directional bias that allows them to move in any direction.

This process involves a little more sophistication, as the rotational speed of each propeller needs to be adjusted for the drone to move in the intended direction. This control is provided by the Electronic Speed Controller (ESC) module of each motor

If you’ve been spent some time shopping for drones, then you have undoubtedly come across the terms “brushed” or “brushless” motors. What’s the difference between the two? Is one better than the other?

FeaturesBrushed MotorsBrushless Motors
CommutationBrushedElectronic
ManintenancePeriodicLess/No
Jangka HayatShorterLonger
KecekapanModerateHigh
KelajuanLowerHigher

6. Propeller

As the props spin, air flows over the top of the wing to create low air pressure. At the same time, high air pressure occurs underneath the wing which effectively pushes the quadcopter upward.

For the props to be able to spin to such incredible speed, it would require powerful motors.

The more power the motor generates, the faster the blades spin. Moreover, the faster they spin, the more lift they create.

The motor’s power and capacity have a lot to do with the flight performance. However, there are also other characteristics that can influence the efficiency of the drone propellers such as the angle of attack, size and thickness, balance and number of blades.

7. GPS

Parrot GPS Board

By providing (relatively) precise positional data, GPS enables flight modes including fixed hovering, auto return home, orientation control, and safety “bubbles” that limit how close the UAV can get to the pilot.

GPS also provides an extra level of granularity to further enhance flight stability.

8. Optical Flow

Optical flow is a feature that allows the drone to hold its position without a pilot’s input. It is a feature that works by having a downward-facing camera “view” the ground surface while sending a continuous flow of optical feed back to the flight controller which then makes flight adjustments to keep the drone in its position. 

For instance, if the FC senses that the drone is drifting backwards, it will make appropriate adjustments to counter that movement.

9. Telemetry / OSO

Telemetry is data about your flight—speed, altitude, battery voltage, etc. This can be viewed in several ways. The old-school way is via a display built into transmitter.

In some cases, the telemetry will operate on its own radio system with a unique frequency, so a transmitter with a dedicated telemetry receiver or the ability to install one is required.

More recent is on-screen display (OSD), an addition to FPV that superimposes select data over the video feed from the flight camera. In this case, an OSD module is required, through which the video feed will pass after leaving the camera, and before arriving at the video transmitter.

10. Ground Station

A ground station is some software that runs on your PC, or tablet that you can use to monitor where your drone is flying, set new waypoints, or tell your drone to do other commands such as follow you. Most drone pilots will use a smartphone or tablet as their ground control station.

However depending on what autopilot you use this might not be possible.

Important features to note when choosing a drone

1. Camera

Built-in cameras give you the flexibility in how you use your drone for video and photography. Most Film directors and shooting experts love to buy drones equipped with a camera to capture spectacular shots at tough locations, they are also used in football matches to capture every angle of the field.

2. GPS

Drone guide for dummies

An introduction to drones and advice before you buy.

The word “drone” got its origins from an old English word drān, which referred to a male bee whose job is to mate with the queen bee or a monotonous sustained sound.  When we think of drones, we think of a missile or a remote-controlled pilotless aircraft, a surveillance tool meant to keep watch over a place or an innovation developed for delivering products.

Quadcopter with radio controller.

Important features to note when choosing a drone

1. Camera

Built-in cameras give you the flexibility in how you use your drone for video and photography. Most Film directors and shooting experts love to buy drones equipped with a camera to capture spectacular shots at tough locations, they are also used in football matches to capture every angle of the field. The filmmaking industry is utilizing them commonly for movie footage.

Within the last years, the prices of drones have dropped so the numbers of buyers have increased. You can easily buy one in the price range of $100 to $1000 only. Most of the action cameras these days are manufactured with special drone mounting capabilities.

The highly advanced DJI Inspire camera drone.

2.GPS

One important feature that a drone can come with is GPS compatibility, Most Higher priced drones have it and most lower priced models don’t. 

These units are gaining more and more popularity these days as they are capable enough to capture location information on the go. You can send this drone to record scenes at any fixed location as they are highly stable and they will come home after completing a task.

An interesting fact to know is that they have a “Return to home” feature which will allow the drone to remember the last shoot location and can be sent again to the same position for next shoot.

3. Stabilizer

Gyro stabilization technology is majorly developed for improving the flight capabilities of drones. Drones today are designed with three and six-axis gyro stabilization technology so that your device can stay stable in air and can manage movements at steeper turns.

Its central flight control mechanism helps users to enjoy smooth flights even in strong winds and it allows us to film spectacular aerial views.

4. FPV (First Person Viewing)

It is a very common application of drones in which a video camera is mounted on the drone and broadcasts live video to the pilot on the ground so the pilot is flying the aircraft as if he was on-board instead of looking at the drone from the pilot’s actual position.

It is possible to control these drones by sight with the help of a portable monitor. FPV controls allow the drone to fly around obstacles more precisely especially with drones like quadcopter which can fly indoors and through rough terrains.

5. Sensors

  • Accelerometer – They calculate the drone’s current altitude and perform necessary corrections.
  • Magnetometer – Measure the magnetic force like a compass to help in locating the drone.
  • Barometer – It is a pressure sensor also used to detect the drone’s altitude by noticing changes in air pressure when the drone moves a bit.
  • Airspeed Sensor – It measures how fast air passes the drone.

Choosing A Drone

  • Buy a drone that complies with your skill level
  • Buy a drone that you can afford
  • Buy a drone that has only the features you need

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