Introduction to drones: basic knowledge

The use of drones in aerial photography has grown rapidly in the past few years, and the market is now full of a variety of Drone products, from small consumer models to complex commercial applications. Whether you are a beginner who just wants to play, or a practitioner who wants to try commercial aerial photography, this is the best time for you.

 If you are a little white who hasn't flown the drone before, it may seem a little daunting, but it does n' t matter. All you have to do is understand it and master it. This series of articles is very suitable for you, we will be divided into three parts, the first part of today will explain the basic characteristics and components of most Drone systems, and in the second and third parts of the future, We will discuss how to choose the most suitable Drone for you and the safety knowledge we need to know before the first flight.

 What is a drone?

 Often we call remote-controlled aircraft "drones ", and in English, in addition to the most commonly used" drone","(Drone" vehicle) and "(UAS" aircraft system). Drone and drone refer to unmanned aircraft, while UAS refer to the entire Drone system. The Drone in this paper refers to the civilian products used in aerial photography.

 

A complete set of UAS can be called

 Each Drone system has its own differences, but some basic common ground. In addition to Drone flight mechanisms, for example, they usually include lithium batteries for power, cameras mounted on stable cloud heads, and radio communication systems. Most drone products also include a dedicated controller, and some cheaper consumer models can only be controlled using smartphones.

 From the appearance, most Drones seem to be a simple device, but in fact they adopt some quite advanced technology, including the various sensors used to track the position of Drones GPS、 to avoid collisions and even to track the intelligent flight mode of mobile subjects and so on.

 Drone

 The core of any system is aircraft. At present, most consumer Drones are four-axis design, and the high-end models used in film shooting have six-axis or even eight-axis design. Today's multi-axis drones use fixed pitch propeller systems, while most models use removable propellers made of plastic or fiberglass composites with simple torsional locking systems. Some models offer foldable propeller designs.

 

DJI Phantom 4Pro twist lock propeller and DJI Mavic Pro folding propeller

 The propeller of the Drone is driven by a brushless motor and rotates at high speed to generate the thrust required for flight. Each motor has a corresponding speed control unit, which can fine-tune the rotor speed. And by changing the relative speed between the propellers, the Drone can be pitching, turning, rolling and lifting.

 Flight controller

 The flight controller allows the user to direct orders to the Drone, which is connected by a radio control system, usually 2.4 GHz or 5.8 GHz.. The flight controller enables the user to order the Drone directly signals from the flight controller rocker are sent to the Drone to manipulate the Drone action by adjusting the speed control unit on each motor.

 At the same time, the radio can transmit video signals from the Drone to the controller screen, showing real-time images of the camera carried by the Drone. A lot of times watching the screen is just an Android or Apple mobile device, paired by APP. Some of the more advanced models have built-in screens.

 

In addition to controlling the flight action of Drone, most controllers also integrate camera control function and additional interface, which can realize the operation of cloud head motion, recording / stopping and so on, and more settings can be accessed through touch screen.

 Stable cloud head

 If you want the drone to take photos or videos in the air, be sure to keep the image stable. The high altitude environment is not as stable as imagined, and the change of airflow will inevitably affect the motion of Drone. If the drone carries an excellent stable cloud head, it can compensate for sloshing and obtain a stable image of the process.

 

Most Drones use a three-axis stable cloud head, which can keep constant in three axes: pitch, roll and roll. A triaxial cloud platform is consistent with the principle of electronic stabilizers commonly used in the industry. In some large movie-grade Drones, stabilizers such as MoVi、Ronin can be installed directly to carry the film camera.

 Global Positioning System

 When the Drone takes off, of course you want it to stay in its intended position or route. Although skilled Drone pilots can do their work without GPS assistance, Nowadays, almost all Drones rely on GPS technology to achieve high-precision automatic mission execution.

 GPS advantage of the system is that the computer can be used to make adjustments to compensate for the influence of wind direction and airflow, so that the flight of Drone can be mastered more easily, and even the automatic flight of preset trajectory can be realized. GPS, however, also has the possibility of failure, so learning drone manipulation is an important part of flying without GPS.

 Anti-collision system

 Over the years, the crash-proofing system has been a major technological advance in identifying and avoiding obstacles through visual, acoustic and infrared sensors. Visual sensors allow drones to "see" objects and stop before the plane hits, but its recognition distance is usually limited (about 15 meters).

 Sound systems use bat-like ultrasound to sense objects, usually for automatic landing operations. while the infrared sensor is an updated option, it is similar to the way the visual sensor works, the detection distance is not far away, and it is also not suitable to work in low light conditions.

 These systems can help novices avoid collisions and aircraft damage, but it is important to remember that flying hands are ultimately responsible for flight safety, and collision prevention systems are useful, but not absolute.

 

A small circle in front of the DJI Mavic Pro that looks like a small eye is a visual sensor for the anti-collision system.

 Battery

 Most Drone products are powered by lithium batteries, which have a wide variety of shapes, sizes and rated power. Smart batteries with built-in charge/discharge regulators and sensors are able to report battery voltage and temperature through applications or external buttons. The single flight time of the Drone is generally between 15 and 30 minutes, depending on the model of the Drone, the flight environment and the intensity of the control operation.

 Lithium batteries have a high energy density, so special care is needed, and improper handling may be life-threatening. Traveling with these batteries can be dangerous if appropriate precautions are not taken. According to the aviation policy of most countries, there are special regulations and restrictions on carrying batteries on commercial flights.

 Intelligent Flight Mode

 Early drones were just a tool to get your camera off the ground and fly into the air, and with the development of technology, modern drones can do more.

 many Drones today use GPS、 computer vision as well as subject tracking techniques to help users achieve more complex tasks, including various "semi-autonomous" intelligent flight modes. Common examples include active tracking of the main body, around the main body, following the programmed navigation point route automatic flight and so on.

 

Smart flight mode allows flying hands to get very creative shooting with minimal effort, allowing users to focus more on creative aspects. but need to be reminded that you also can not rely on them completely, you have to learn how to fly autonomously in order to disable these functions in an emergency.

 Which manufacturers are making drones

 Today, there are countless manufacturers of drones, most people are familiar with DJI, this is the highest market share of heavyweight players. Of course, you can also find some satisfactory models in Yuneec、Autel Robotics、GoPro and Parrot products.

 

Although the products of these manufacturers can be classified into the same category, each model of the product is different, they have different design concepts and technical characteristics. In the second part of this series, we will discuss how to select the Drone that best meets your own needs.

 Conclusion

 Drones are an amazing tool that allows people to remotely control aerial photography, which is extremely low cost and more secure than manned aircraft. As technology advances, these devices will function better and better, and if you've been looking for a way to bring a new perspective to your image work, you can consider flying up the sky. Of course, first of all, you must remember safety first and follow local laws. We will also discuss this issue in subsequent articles