Drones: Driving Low-Altitude Economy and National Growth
06 Jun 2024
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Historical Development of Drones
The development of drones began shortly after the end of World War I. Following World War II, many military powers around the world independently converted various retired combat aircraft into target drones, an action that initiated the modern development of drones. With advancements in electronic technology, drones increasingly demonstrated their superiority in reconnaissance missions. For example, during the Vietnam War, the U.S. military frequently used drones to scout high-value or heavily defended targets on the battlefield.
Recent Industry Developments
The "2024 8th World Drone Conference and International Low-Altitude Economy and Unmanned Systems Expo / 9th Shenzhen International Drone Exhibition / Autonomous Driving and Unmanned Vehicle Technology Exhibition," themed "Low-Altitude Economy, The Future is Here," successfully concluded at the end of May in Shenzhen, the drone capital. The conference was attended by over 10,000 industry experts, scholars, and entrepreneurs from more than 110 countries and regions. The event featured over 30 parallel forums and more than 60 product and technology exchange meetings, covering topics such as drones and the low-altitude economy, low-altitude digital transportation, low-altitude flight services, eVTOL technology innovation and application, low-altitude airspace openness and management, logistics emergency drones, AI robots, manned unmanned aerial vehicles, low-altitude flying cars, low-speed unmanned vehicles, and aquatic unmanned systems.
Currently, the drone industry is also a new high-tech sector involving numerous fields, from product research and development, production and manufacturing, to industry use, management, and services. The industry chain spans many high-tech areas. The upstream primarily includes new materials such as composite materials for drone bodies, weapon-carrying equipment, control systems, launch and recovery devices, and other components. The downstream markets are mainly military and civilian, with a focus on military applications, but also including scientific research, agriculture, power, transportation, meteorology, and many other industries. There is vast potential for development in the civilian sector as well.
Whether it's DoorDash and Wing's collaboration on drone delivery services in Virginia, Lego's drone light show showcasing children's spacecraft designs, the UK's plan to build a drone "superhighway," or Aerodome's initiative to use drones for crime scene emergency response, all these examples demonstrate the increasingly widespread application of drones across various fields. Even a brutal clash between two Middle Eastern countries in 2020 highlighted the significant role of drones, as countless bystanders realized through various platform reports that the essence of future development lies in drones: those who control drones will dominate! The next 10-20 years are expected to be a golden period for drone development, with market demand expanding and continuous breakthroughs in high technology, offering immense potential for growth.
Introduction to Drone Hardware Components and Structure
1. FrameThe frame is the skeleton of the drone, supporting all the electronic components. As shown in the image, all the electronic components are fixed to the frame to function properly. The size of the frame is distinguished by the wheelbase, with larger frames requiring more powerful motors and larger propellers; otherwise, the drone cannot take off. Currently, frames are mainly made of plastic and carbon fiber. Carbon fiber has better mechanical properties but is more expensive.
2. Propellers
Propellers are of specific models, and according to physical principles, the rotational inertia of the propeller (relative to the axis of rotation) is approximately proportional to the fifth power of the radius. Therefore, larger propellers respond more slowly and are less able to change their state of motion (i.e., rotational speed). Propellers also come in clockwise and counterclockwise versions. When a single propeller is driven by the motor, it generates a force that causes the drone to rotate horizontally along the central axis. To counteract this, different propellers must be set to rotate in different directions; otherwise, a multirotor drone would continuously rotate after takeoff. However, based on this principle, the rotational speed can be used to control the drone's yaw movement. Generally, smaller propellers with high rotational speeds contribute to increased stability, allowing the drone to fly more steadily, but this comes at the cost of shorter endurance.
3. Motors
The motors used in drones are specialized three-phase brushless motors. These motors have three terminals (with no positive or negative polarity, allowing reverse rotation by switching any two terminals). They rotate in one direction, have high power output, low friction, and can provide significant lift.
The motor's KV value indicates the number of revolutions per minute (RPM) the motor will make per volt when unloaded. For example, a 400KV motor means that at 1V, the motor will turn 400 times per minute without any load.
Brushless motors of the same series and physical dimensions will exhibit different KV characteristics depending on the number of winding turns. Motors with more winding turns have a lower KV value, resulting in a lower maximum output current and higher torque. Conversely, motors with fewer winding turns have a higher KV value, resulting in a higher maximum output current and lower torque.
However, a higher KV value does not always mean better performance. With the same power, a higher KV value means the motor provides less torque. Therefore, high KV motors are paired with smaller propellers, and low KV motors are paired with larger propellers. For example, a 380KV motor typically uses a 16-inch diameter propeller, while a 980KV motor uses a 10-inch diameter propeller. Even higher KV motors may be equipped with 6-inch or 4-inch small propellers, or used as ducted fans (used in fixed-wing aircraft, such as fighter jets, for rear propulsion).
4. Electronic Speed Controllers (ESCs)
Electronic Speed Controllers (ESCs) are electronic devices that receive PWM control signals and regulate the speed of the motors. They can accept PWM signals from a Pixhawk flight controller or a signal receiver, and then control the motor's rotation. Currently, multi-rotor drones commonly use the Hobbywing brand, with the Letai models specifically designed for multi-rotor use.
As shown in the image, the ESC has three types of wires. The three black circular connectors (known as banana plugs, as shown in the second image above) connect to the brushless motor without regard to polarity; reversing any two connections will reverse the motor's rotation direction. The long, thick black and red wires connect to the power supply, with the black wire connected to ground (negative) and the red wire to Vcc (positive). It is crucial not to reverse these connections, as doing so will damage the ESC when power is applied.
Lastly, the twisted black and white wires are the signal wires, which receive control signals and regulate the current. The black wire is the ground, and the white wire is the signal line, which connects to the signal receiver or the output end of the flight controller.
5. Current Sensor
A current sensor is not just a device that displays the current value; it is a module that supplies power to the flight controller. It connects to high-voltage lithium batteries and outputs a stable voltage to drive the flight controller. The current sensor for the Pixhawk 4 (as shown in the image) integrates even more functions, serving as a hub for supplying power to the ESCs (acting like a power distribution board) and as an adapter board for the flight controller (extending multiple pins from the flight controller to help reduce its size).
6. Battery
The battery is the power source of the drone, specifically designed for high discharge power and efficiency. "1S" indicates a single lithium battery cell in series (drones use lithium batteries connected in series). For example, a 3S battery consists of three lithium cells in series. The larger the drone, the higher the voltage required. For instance, a 450-sized drone typically uses a 3S or 4S lithium battery, a 680-sized drone uses a 6S lithium battery, and very large drones (with a wheelbase of over 1000mm) may use a 12S lithium battery.
Each lithium battery cell has a full charge voltage of 4.2V and a nominal voltage of 3.7V. Therefore, when the battery reaches its maximum voltage (4.2V per cell), it is fully charged, and when it reaches its minimum voltage (3.7V per cell), it should no longer be used to prevent damage.
Future Trends of Drones
1.Logistics and DeliveryFrom the rapid delivery of everyday goods to the timely transport of emergency medical supplies, and even acting as "romantic messengers" delivering surprises and warmth, the drone logistics and delivery industry has quietly integrated into people's daily lives. For example, companies like DoorDash and Wing have already begun testing drone delivery services to enhance speed and efficiency. In the future, drones could become common tools for express delivery, especially in urban environments and hard-to-reach areas. (Homepage | Defensebridge)
2. Public Safety and Law Enforcement
The application of drones in public safety and law enforcement is also expanding. Police departments can use drones for surveillance, tracking, and emergency response. For example, Aerodome has begun using drones at crime scenes to provide real-time video and data support. This technology can enhance the efficiency and safety of law enforcement agencies.(MIT News) (Pilot Institute)
Drones have significant potential in infrastructure monitoring and maintenance. They can be used to inspect bridges, pipelines, power lines, and buildings, providing efficient and cost-effective solutions. For example, in the UK, there are plans to build a drone "superhighway" to support the use of drones in logistics and infrastructure monitoring.(MIT News)
Agriculture is another important field for drone applications. Drones can be used for crop monitoring, pest management, and precision fertilization. They are capable of providing high-resolution images and data, helping farmers increase yields and reduce resource wastage.
The application of drones in entertainment and education is also increasing. For example, Lego held a drone light show showcasing children's spacecraft designs. This demonstrates the creative use of drones in entertainment and education.(Homepage | Defensebridge)
Drones will play an important role in future smart cities. They can be used for traffic monitoring, environmental surveillance, and public services. By integrating with Internet of Things (IoT) devices, drones can provide real-time data to help city managers make better decisions. (MIT News)
7. Technological and Regulatory Developments
As drone technology advances, new algorithms and artificial intelligence technologies will further enhance the autonomy and efficiency of drones. For example, new algorithms developed by MIT can help drones handle tasks in complex environments more efficiently.(Pilot Institute) Additionally, as the applications of drones expand, related regulations and policies will continue to be refined to ensure the safety and privacy protection of drone operations.
Drones have become an important support for the development of the low-altitude economy
As the leading industry in the low-altitude economy, drones have an annual growth rate exceeding 20%, becoming a new growth point for the national economy. They provide new means for social public services, effectively supporting the modernization of government governance capabilities and systems. Drones also offer new space for regional economic development, optimizing regional economic layout and promoting three-dimensional regional economic growth.
Vigorously promoting the development of the low-altitude economy not only helps expand market space but also meets the inherent demand for high-quality development. The low-altitude economy inherits traditional general aviation modes while integrating new low-altitude production services supported by drones. Relying on information and digital management technologies, it forms a highly dynamic and creative comprehensive economic form that accommodates and promotes coordinated development across multiple fields. To achieve better development of the low-altitude economy, low-altitude openness is an inevitable trend. Building urban low-altitude skyways to support the large-scale and commercial development of drone applications, the low-altitude economy represented by drones is also expected to become a new engine driving social and economic growth.
