What is a Drone?
The term “drone” is an all-encompassing one that was originally used in describing aerial unmanned or “pilotless” aircrafts. Today, the term is used amorphously to describe all kinds of remote controlled aerial vehicles but there is a better defined distinction of the various unmanned vehicles in existence today.
Broadly, the unmanned flying systems (UAS) can be described using any of the following terms:-
- UAVs or Unmanned Aerial Vehicles
For the mass consumer market, all these “unmanned systems” are simply referred to as drones but we will attempt to highlight the distinctions between the terms. In some cases, it is simply a question of semantics where one term is more informally used by “laymen” while the other is a technical term and name used by professionals in the robotics or electronics industry to describe the unmanned aerial vehicles.
The term “drone” is used in a very broad sense in describing all kinds of remotely controlled vehicles. Many experts prefer to call these quadcopters and reserve the term drone only for unmanned aircraft systems that are capable of autonomous flight.
In technical terms, a drone can, theoretically, describe anything from a remote controlled car to a full size remote controlled airplane to an autonomous aircraft like the ones used in the military capable of flying on its own and returning to the starting point. However, in common jargon, when someone talks of a drone, they are usually referring to a multirotor or quadcopter or generally, a consumer drone.
The term UAV or Unmanned Aerial Vehicle is probably the most all-encompassing. It refers to all kinds of unmanned flying objects ranging from the small toy drones to the military grade drones used in war and espionage. If you are a consumer planning to buy a small remote controlled aircraft for hobbyist flying and other uses, of course you will simply say that you want a drone not “can I buy some unmanned aerial vehicle”. It is more of a technical term.
Thanks to the popularity of quadcopters, many users are now using the term “quadcopter” in place of a drone. In other words, they are referring to all drones as quadcopters which is inaccurate. A quadcopter is simply a drone or UAV with four propellers. The name quadcopter has become synonymous with all drones because most of the leading drone manufacturers in the market such as DJI are now exclusively manufacturing quadcopters.
What Makes a Drone a Drone?
By “drone”, we mean the consumer drones or the small to medium sized drone used by individuals and small businesses for various functions ranging from recreation to photography and product deliveries.
In this market, too, there is a good deal of differentiation. They range from those with simple functions to more complex drones with superior functions. Depending on its class and technical capabilities, a drone can be equipped with everything from GPS navigation to sensors and much more.
Like every human invention, drone technology has been evolving constantly over the years. Initially, developments were geared towards improving range and various functional aspects. There was also a strong trend towards drone miniaturization. Today, we have drones so tiny that you can fit them in your palms and fold your hands to cover them. Drone technology development has mainly focused on the following areas:-
- Motors: The need for powerful and durable motors with an impressive lifetime. The lifetime of motors is generally expressed in terms of hours. The higher the lifetime, the longer the motor is likely to last without the need for replacement. Today, it is not uncommon to find drone motors with a lifetime of at least 5000 hours though most of the low-end drones still have a relatively short lifetime.
Battery: Improvements are being made to have drones fitted with batteries that can offer longer flight times. Most of the consumer drones in the market currently offer 5 to 15 minutes of flight time. Currently, the best flight times for consumer drones is about 23 to 28 minutes found in the higher end DJI Phantom drones.
- GPS Navigation: This is an important feature in most modern drones allowing the operator to track the position and location of a drone from a smart device.
- P2P Streaming: Modern drones are being equipped with P2P streaming technologies allowing the drones to stream live footage to a remote smartphone or tablet as it is being shot.
- Light weight: Drones are getting smaller and lighter even as their functionality and features improve.
- Cameras: Modern drones are equipped with high resolution cameras capable of capturing clear photo and video footage.
- Obstacle Avoidance: One of the main challenges of flying a drone is a high probability of collision with objects in its path. Obstacle avoidance technology helps lengthen the lifespan of drones by minimizing collisions. Intelligent obstacle avoidance technology will maneuver drones around walls and trees using technologies such as infrared sensors.
- Instant take off and landing: Improvements in technology means that many modern drones can take off right from your palm.
Modern Drones are equipped with the following technologies to facilitate smooth flying and various other functions:-
The gyroscope stabilization is one of the main features of drones that facilitates a smooth flight. The gyroscope should be highly sensitive and respond promptly to the forces that might derail the quadcopter flight.
In quadcopters, gyroscopes are an essential feature of the flight. In practice, the gyroscope cannot fly without the gyroscope; it needs it along with the accelerometer in order to stay stable in the air and fly smoothly.
To understand the importance of the gyroscope and the accelerometer, visualize the quadcopter as a steel plate balancing on top of a thin long stick. It is a tough balancing act but in the quadcopter, this is easily achieved through the gyroscope-accelerometer combination. The accelerometer will send signal to the drone if it is falling too fast off the “stick” and the gyroscope tells drone where it is falling over. This allows the drone to automatically apply sufficient amount of power to the right motors that drive the rotors and props that will balance the drone and get it out of its fall. It is a very effective stabilization action. This action occurs within a micro or millisecond. No human being can respond that fast and drive several motors simultaneously to stabilize the quadcopter. The gyro stabilization is thus a highly sophisticated balancing act.
There are three core pieces of information needed to balance the quadcopter flight. One is the motor speed. The other variables are fed into a negative feedback loop by the accelerometer and the gyroscope. The accelerometer detects the current rate of acceleration of the quadcopter and the gyroscope is a part of the inertial measuring unit (IMU) which helps in detecting variables such as the yaw, roll and pitch of the quad. All these are part of the multirotor’s flight controller which is literally the “console point” of the drone. It is the reason they are highly stable in flight. They prevent the quad from degenerating into undampened oscillations when in mid-air.
No-Fly Zone Technology
Drones are equipped with various inbuilt safety features to prevent collisions and also prevent them from crashing when they lose battery power. A lot of the latest drones have an even more advanced protective feature through the drone no-fly zone. It is designed to offer you greater flight safety and prevent any accidental flights into a restricted area.
Most of the latest drones such as the Phantom UAV have a no-fly zone firmware that prevents accidental flights into such restricted zones. The US Federal Aviation Administration (FAA) has proposed certain rules that will govern the use of unmanned aircraft systems (UAS) weighing less than 55 pounds for non-recreational uses. The rules cover areas such as height restrictions and limit the use of UAS to daylight and in the visual line of sight. It also has requirements such as user certification and aircraft marking and registrations.
In some of the bigger city such as
Drones with a no-fly zone are usually the higher end ones and will likely cost you more. But technology is evolving fast and soon, the technology will also be available in the cheaper drones.
Drone GPS Technology
Not all drones (quadcopters to be specific in our case) are equipped with GPS technology but the more advanced ones are generally equipped with the functionality. So what is GPS technology and what does it add to your quadcopter?
There are two main ways to fly a drone: you can either steer it manually using your transmitter or you can fly it through GPS wayfinding. The former is obvious and is available in the simpler and cheaper drones. The latter is available in the more advanced drones and involves the deployment of GPS receivers in a control and navigation loop to provide smart drone navigation. GPS in drones is primarily used in navigation and it has the following features:-
Position Hold: The position hold function will maintain a fixed altitude and location of the drone.
Return to Home: With the Return to Home function, you can simply press a button and the drone will get back to its starting point. This is because due to the GPS navigation, the drone is able to “remember” the point at which it started at its flight and will return to that position at the press of a button. It is a pretty marvelous functionality.
Autonomous Flight: With the autonomous flight feature, you can predetermine the flight path of the drone by marking out its GPS waypoints that will chart out its flight trajectory. After setting out your GPS positions and flight path, you can then execute the flight and the drone will fly autonomously using its autopilot.
To fly a drone with a GPS system, it is essential to have some basic knowledge on how GPS systems work.
Internal Compass and Failsafe
Some drones also have an internal compass that will enable the UAV to trace its exact flight location. To operate this, the compass must be calibrated and the home point fixed. The home point refers to the location where the drone will return to in case you lose the connection between the controller-transmitter and the drone. This functionality is also called a failsafe and is a flight safety feature that will ensure you don’t lose your drone even if you lose sight of it.
First Person View or FPV Technology
The First Person View or FPV is commonly used in drone racing and refers to where a video camera fitted on the drone transmits live video images to the operator on the ground. With FPV, you will feel like you are onboard the drone when you are actually several meters away operating the drone controller. It is a very sophisticated feature that gives you a real time view of the terrain covered by the drone from your ground position.
Because you are virtually “on board” the drone, the first person view or FPV allows you to cover a broader range and altitude on the drone compared to someone who is operating the drone and looking at it from the ground. With FPV technology installed on your drone, you can also enjoy more precise flying with your quadcopter. This is what makes it a key component in most of the racing drones in the market. With a First Person View, you can easily navigate the drone around the obstacles on your path. It enables you to fly the drone through narrow pathways including forests and various manmade objects. Most drone racing tracks generally have several obstacles that a user must navigate without crashing the drone. Without an FPV, you cannot race a drone around those narrow confines and obstacles. The technology utilizes a radio signal in relaying and receiving the live video.
The live video signals from the FPV enabled drone can be received by a variety of interfaces depending on the drone type. These can range from tablets to smartphones, remote controllers and computers. To transmit the signals to the receiving device, the drone utilizes a multi-band wireless transmitter that is built into the quadcopter along with the antenna.
The quality of the live video coming to the receiving device on the ground will depend on the strength of the signal between the quad’s ground control. The range over which the live video feed can be transmitted is also dependent on the transmitter technology used. There are new advanced drones with FPV that can transmit live video over a distance of up to 7km or 4.1miles. A good transmission system will enable you to fly the drone farther away from your control position while still receiving very clear FPV HD video feed. The more advanced FPV technologies minimize latency as much as possible while boosting your maximum range thus offering you superior performance and reliability when it comes to the drone’s First Person View characteristics. Some of the more advanced drone racers generally put a great premium on the FPV functionality alongside other important drone performance characteristics such as the flight time and speed.
The need for clearer and high definition video images has also led to greater innovations in this area. Now it is even possible to transmit an FPV live video feed over a 4G or LTE network. For flyers, this capability offers even more enhanced improvements in the latency and range. These drones will typically come equipped with camera modules, data modules and a modem that can either be 4G or LTE.
LED Light Indicators in the Drone
All drones are fitted with LED light indicators. These are installed on the front part as well as on the rear end of the drone. They are generally fitted in the underside of the props. The front LEDs will tell you where the nose of the drone is situated while the rear LED lights show the flight status of the drone when the battery is powered on. The front and rear LEDs have different colors allowing you to easily differentiate the two when the drone is in flight.
The Drone Remote Control System
The remote control is a must-have requirement for flying a drone. Even the so called “autonomous” drones still use some form of remote control. Remote controllers are wireless communication gadgets using certain frequency bands to communicate with the drone. They allow you to control the drone within a certain range depending on the frequency.
When the drone leaves the ground, its firmware should be paired with the drone remote control in order to enable the control. There are a host of things that you can do with the remote control depending on the drone firmware. For example, you can use it to hover the drone at a fixed position at a certain altitude; you can also use the drone RC to take pictures, perform tricks and flips, move the drone forward and sideways and much more.
Apart from the drone controllers, current advanced UAVs can also be controlled using various other third party devices such as smartphones, tablets and even wireless game controllers like the PS4 controllers. Before pairing a drone with a particular controller, make sure that you ascertain their compatibility.
Extenders Drone Range
Once you become an avid drone racing enthusiast, there are various accessories that you add to your drone in order to extend their power and functionality. One of these is the drone range extender. Like the transmitter, it is a wireless communication device running in a certain frequency band that you can use in extending the range of communication between a controller and a drone.
Every drone range extender comes with a unique network name and MAC address and depending on the specs, will extend the range of your controller by several meters. Some can even extend the range by several hundred meters. Given that the latest drones already give you a very good range, an FPV range extender can really push the drone capabilities to a whole new level.
Most professional and even hobbyist drones now come with cameras for quality photography and videography. The best drone cameras will depend on your individual requirements. For consumer drones, the cameras found in some of the high quality drones such as the DJI Phantom 4 would be sufficient but these may not be adequate for a high performance environment where you need to take high speed shots, for example.
There are other high end and costlier drones like the DJI Inspire 2 that are equipped with very powerful cameras. To have the flexibility to fit a camera of your choice, you can purchase drones that are highly customizable which will allow you to experiment with different kinds of cameras. For crystal clear videos, you will need a camera with a resolution of at least 720p/60 frames per seconds.
Cameras in the latest advanced drones such as the DJI Phantom 4, the DJI Inspire 1 and the DJI Phantom 3 Professional are generally of very good quality and are perfectly suited for aerial photography and videography.
Gimbals are an essential feature for the drones used in capturing quality aerial photography and videography. The main purpose of the gimbal is to dampen the vibration of the drone and prevent it from reaching the drone camera. This stabilization action of the drone allows you to capture crystal clear images even if the drone is tilted at an angle. The gimbals can have a 3-axis or 6-axis stabilization with the latter offering the best vibration dampening. The earlier drones may not have a gimbal but all the latest drones in the market currently are fitted with a gimbal.
A gimbal will make your videos and photos look even more professional. There are various types of camera gimbals that you can use on your drone. These include the standard gimbals and the brushless gimbals. There are also numerous drone camera gimbal accessories that you can purchase in order to boost their performance.
Some drones are not fitted with gimbals but are built with electronic image stabilization that allows you to capture high quality footage.
Depending on its intended uses, the possibilities of extending the functions of a drone are simply endless. One way of doing this is by attaching sensors that perform various functions. There are certain basic sensors that are a must-have in almost every drone and make up the “secret sauce” in the drone that makes it function in a certain way. Some sensors can only be found in the higher end drones and offer more specialized functions. Here is an overview of the various sensors found in drones:-
· Inertial Measurement Unit (IMU)
· Current sensors
· Tilt sensors
· Magnetic sensors
· Moving target indicators
· Infrared sensors
· Light Detection and Ranging (LIDAR)
· Photogrammetry Sensors
· Electro-Optical Sensors
· Chemical and biological sensors
· Pressure sensors
· GPS sensors
Of course you won’t find all sensors in a single drone. Rather, certain specialized drones will have certain types of sensors. That is why when buying a drone, the potential area of application is often of great importance. Knowing what you are planning to use your drone for allows you to narrow in on drones that have the desired features.
Like all aspects of UAV technologies, drone sensor technologies are also continuing to evolve. Latest advancements in drone sensor technology application includes the use of Time-of-Flight three-dimensional depth camera sensors which can be put into a variety of applications such as obstacle avoidance, 3D photography, augmented reality drone applications, object scanning and gesture recognition among others.
Sensor technologies such as photogrammetry and LIDAR can be used to fly the drone autonomously and capture photographs in rapid intervals which can be used in 3D mapping and so on.
A sensor technology like Inertial Measuring Unit (IMU) works in combination with GPS to maintain the drone’s flight path and direction. These are particularly important in an ecosystem where many drones are now becoming more autonomous. The operator simply plots the waypoints on GPS and the sensors ensure the drones adhere to flight rules. The IMU sensor technology is based on magnetometers with multiple axes which can detect the changes in direction and feed back the information to the drone’s firmware via a negative feedback loop which will show the drone’s speed, orientation and direction of flight.
Intelligent Flight Control
Autonomous flight or intelligent flight is one of the frontiers in drone innovation and this has already been achieved to a large extent in some of the more advanced drones. Intelligent flight controls range from the most basic such as Return to Home to the more advanced controls such as waypoints plotted on GPS. The DJI range of drones, for example, offers various intelligent flight modes including Follow Me, Waypoints, Point of Interest and Course Lock and Home Lock.
Top Drone Brands
The drone market is littered with numerous companies with many of them coming up every few months as others close shop. While you should judge every drone model on its own merit, there are certain drone brands that have built a reputation for high quality standards and excellent performance. These include the following:-
- Precision Hawk
These vary vastly on factors such as price and performance. Some of them build niche drones targeted at particular niche markets such as agricultural drones, aerial cinematography drones, hobbyist drones and so on.
Drone Buying Guide
Given the large spectrum of drones that are available in the market, it is important to know what you are looking for when purchasing a drone. This will help you choose a quadcopter drone with the right specifications and which will serve its intended purpose:-
The Flight Time: This is one of the most important performance factors to keep in mind. It refers to the duration of flight that the drone will last on a single charge cycle. The higher the value, the better. Drones with higher flight times are generally costlier.
Camera: Not all drones are equipped with cameras. If you are planning to use your drone to take some footage, check to ensure that it is equipped for aerial cinematography. If it has a camera, look at its specifications. Check if it offers you a First Person View or FPV although you are unlikely to find this in the cheaper drone models.
Skill Level: If you are planning to purchase a drone, you must factor in your skill level. If you are a beginner, then you will need to purchase an beginner drone. These tend to be cheaper and easier to fly. If you purchase a drone that is above your level and more expensive and difficult to fly, you are going to crash it and waste a lot of money down the drain. It is better to work on your skills using a cheaper drone.
Drone Controllers: The Drone Flight controller experience is also an important factor in the operation of drone. Most drone transmitters are built with two analogue sticks and operate in a 2.4GHz frequency. However, there are more advanced transmitters that offer you more detail about your drone flight.
Price: This is also an important consideration. Drone prices can range anywhere from $15 to $2000 depending on its functionality and performance so you should budget accordingly depending on the features that you are looking for.
If you liked this article, you should check out our article on drones for real estate photography