[UAV assembly and debugging] series of courses:
Chapter 2 Questions about the manual of the new Sida 30A ESC
Chapter 3 Servo Installation and Adjustment
1.1 What is a drone?
Unmanned aircraft refers to a type of aerial vehicle driven by power and not carrying operators. It relies on aerodynamics to provide lift for the aircraft, can fly autonomously or remotely, can carry multiple mission equipment, perform multiple tasks, and can be used once or repeatedly for unmanned aerial vehicles, referred to as unmanned aerial vehicles (Unmanned Aerial Vehicle, UAV).
Unmanned aircraft is abbreviated as "UAV" ("UAV"), which is an unmanned aircraft operated by radio remote control equipment and self-provided program control devices. UAV is actually a general term for unmanned aerial vehicles. From a technical perspective, it can be divided into: unmanned fixed-wing aircraft, unmanned vertical take-off and landing aircraft, unmanned airship, unmanned helicopter, unmanned multi-rotor, unmanned Para-wing aircraft, etc. Compared with manned aircraft, it has the advantages of small size, low cost, convenient use, low requirements on the combat environment, and strong battlefield survivability. Due to the importance of unmanned aircraft for future air warfare , major military countries in the world are stepping up the development of unmanned aircraft. In November 2013, the Civil Aviation Administration of China (CA) issued the "Interim Regulations on the Management of Civil Unmanned Aircraft System Pilots", and the China AOPA Association is responsible for the related management of civilian drones. According to the "Regulations", the operation of drones in mainland China can be divided into 11 situations according to the size of the aircraft type and the flight airspace. Among them, only drones of 116 kg or more and airships of 4,600 cubic meters or more fly in the converged airspace and are managed by the Civil Aviation Administration , The rest, including other flights including the increasingly popular miniature aerial vehicles, are managed by industry associations or by the operators themselves.
1.2 Classification of drones
The application fields of UAVs are very wide, and the size, weight, performance and tasks of UAVs are also very different. Due to the diversity of drones, there are multiple classification methods for drones from different perspectives.
1.2.1 Classification by purpose
UAVs are classified according to their purpose and can be divided into two categories: military UAVs and civilian UAVs.
Military UAVs: According to different military uses and combat missions, military UAVs can be divided into unmanned reconnaissance aircraft/surveillance aircraft, unmanned combat aircraft, communication relay UAVs, electronic jamming UAVs and target drones. .
(1) Unmanned combat aircraft: refers to drones that can carry small and powerful precision-guided weapons, laser weapons or anti-radiation missiles to perform air combat or ground attack missions. As shown in the picture is the U.S. MQ-9 "Reaper" unmanned combat aircraft. The MQ-9 "Reaper" UAV is a new type of extremely lethal unmanned combat aircraft. In addition to attacks, it can also perform intelligence, surveillance, and reconnaissance tasks.
(2) Unmanned combat aircraft: refers to drones that can carry small and powerful precision-guided weapons, laser weapons or anti-radiation missiles to perform air combat or ground attack missions. As shown
Show is the U.S. MQ-9 "Reaper" unmanned combat aircraft, MQ-9 "Reaper" UAV is a new type of extremely lethal unmanned combat aircraft. In addition to attacks, it can also perform intelligence, surveillance, and reconnaissance tasks.
(3) Communication relay UAV: As an air relay platform, communication relay UAV can increase the transmission distance of information, that is, use UAV to transmit images and other signals to other military aircraft or land and navy aircraft. Humans and machines are generally equipped with UHF or VHF radio communication equipment. As shown in the figure is an unmanned airship that can be used for air command and communication relay missions.
(4) Electronic jamming UAV: Electronic jamming refers to the use of active or passive electronic jamming equipment to destroy the enemy's communication system and interfere with the enemy's electronic equipment by radiating electromagnetic waves or releasing aluminum foil and metal jamming wires to make it effective Low, or even completely ineffective. At present, many unmanned electronic jammers adopt passive interference methods, and their basic interference devices include aluminum chaff dispensers, tracer bomb dispensers, and radar echo enhancement equipment.
(5) Electronic decoy/deception UAV is also a passive deceptive jamming UAV. Use the jamming equipment carried on the aircraft to enhance the reflected echo of the ground radar, simulate the real target, and simulate the movement posture of the fighter or bomber through the speed and shape of the aircraft to induce the enemy radar or ground air defense weapon to start or fire , So as to expose the location of ground radar or ground air defense weapons, consume local firepower, and then use other weapons and equipment to carry out precise strikes against enemy radar or ground air defense weapons. Figure 1-5 shows the micro decoy UAV MALD-J equipped by the US Air Force for F-16 and B-52. The MALD-J decoy UAV is a flying air-launched decoy that can be used on enemy radars. The radar and flight characteristics of enemy military aircraft consume the opponent’s air defense force.
Civilian UAVs: In the civil field, UAVs are widely used due to their relatively low cost, no risk of casualties, strong survivability, good maneuverability, and ease of use. Its main application markets include: aerial photography, aerial photography, geological and landform surveying and mapping, forest fire prevention, earthquake investigation, nuclear radiation detection, border patrol, emergency disaster response, crop yield estimation, farmland information monitoring, pipeline inspection, high-voltage transmission line inspection, wildlife protection , Scientific research experiments, maritime reconnaissance, fish situation monitoring, environmental monitoring, atmospheric sampling, precipitation enhancement, resource exploration, drug control, anti-terrorism, police investigation and patrol, public security monitoring, fire investigation, communication relay, urban planning, digital city construction, etc. Areas. Table 1-1 shows the classification of civilian drones.
1.2.2 Classified by flight platform configuration
According to the flight platform configuration, UAVs can be divided into:
Fixed-wing UAVs, unmanned helicopters, multi-rotor UAVs, unmanned airships and para-wing UAVs, etc. The picture shows the most common UAV flight platforms.
1.2.3 Sort by size
According to the weight and size of drones, drones can be divided into micro drones, small drones, medium drones and large drones.
The weight of a large UAV is generally greater than 500～800kg;
The weight of medium-sized drones is generally within 200～500kg;
The weight of light UAV is generally 100～200kg;
The weight of a small drone is generally within 1-100kg;
The weight of the micro drone is generally less than 1kg. Table 1-2 shows the weight and size data comparison of drones classified by size.
1.2.4 Classification by flight performance
(1). Classification by speed
UAVs are classified according to speed and can be divided into:
Low-speed UAV, subsonic UAV, transonic UAV, supersonic UAV and hypersonic UAV.
The speed of low-speed UAV is generally less than 0.4Ma (Ma is Mach number);
The speed of subsonic UAV is generally 0.4～0.85Ma;
The speed of transonic UAV is generally 0.85～1.3Ma;
The speed of supersonic UAV is generally 1.3～5Ma;
The speed of hypersonic UAV is generally greater than 5Ma.
Figure 1-10 shows the appearance comparison of supersonic and hypersonic drones.
(2). Classification by voyage
According to the voyage (or radius of activity), drones can be classified into:
Ultra-short-range UAV, short-range UAV, short-range UAV, medium-range UAV and long-range UAV.
The activity radius of the ultra-short-range UAV is between 5-15km,
The radius of short-range UAV activity is between 15～50km,
The short-range UAV has an activity radius between 50 and 200km,
The radius of the medium-range UAV is between 200～800km,
The radius of the long-range drone is greater than 800km.
Figure 1-11 shows the RQ-3 "Dark Star" long-range unmanned reconnaissance aircraft developed by Lockheed Martin, with a combat radius of more than 900 kilometers.
(3). Classified by practical ceiling
UAVs can be classified according to practical ceilings:
Ultra-low-altitude drones, low-altitude drones, medium-altitude drones, high-altitude drones and ultra-high-altitude drones.
The practical ceiling for ultra-low-altitude drones is generally between 0 and 100m.
The practical ceiling for low-altitude drones is generally between 100 and 1000m.
The practical ceiling for hollow UAVs is generally between 1000～7000m,
The practical ceiling for high-altitude drones is generally between 7000 and 20000m.
The practical ceiling for ultra-high altitude UAVs is generally greater than 20000m.
Figure 1-12 shows China's "Rainbow-3A" inspection and attack integrated hollow drone with a combat radius of 200 kilometers.
1.3 Development of drones
Starting from the first UAV invented in 1917, to today’s military UAVs such as unmanned reconnaissance aircraft and unmanned fighter jets, as well as civilian UAVs widely used in aerial photography, geological and geomorphological mapping, forest fire prevention, etc. , The development of UAV has experienced nearly a hundred years of history. UAVs are gradually being valued by countries all over the world for their advantages such as no risk of casualties, strong survivability, good maneuverability, ease of use, and low cost, and are gradually replacing manned aircraft in many fields, taking on more and more flights. task.
The development of UAVs has roughly gone through the following stages: In the 1920s and 1960s, UAVs were mainly used as target drones, which was the initial stage of UAV development; in the 1960s and 1980s, unmanned reconnaissance aircraft and electronics War UAVs have emerged on the battlefield, and UAVs have begun to enter the practical stage; since the 1990s, UAVs have been fully used in modern high-tech local wars, and UAVs have also been rapidly developed in the civilian field. , UAV is in a stage of rapid rise and vigorous development.
During the two world wars, military UAV technology was mainly embodied in missiles and unmanned drones. In 1918, France’s first radio-controlled aircraft was successfully tested; in 1921, Britain developed the world’s first practical unmanned target aircraft, which can fly at an altitude of nearly 2 kilometers at a speed of 160Km/h . In September 1931, the British Fairey Company converted a "Queen" manned biplane into a "Fairey Queen" target drone for 9 minutes of controlled flight. In 1932, the British Home Fleet took the "Queen Ferry" to the Mediterranean Sea for tests to test the effectiveness of the Home Fleet's air defense firepower and the flight performance of the drone. At that time, "Queen Ferry" flew against the intensive air defense firepower of the Home fleet for 2 hours without being hit. This not only demonstrated the inefficiency of naval air defense weapons at that time, but also fully proved the practical value of the drone. In 1933, Britain developed the famous "Queen Bee" (Queen Bee) drone, which was then put into mass production. A total of 420 such drones were produced from 1934 to 1943, and their use continued until after World War II.
It can be said to be a typical representative of the development of the drone during this period. At that time, in order to train fighter pilots and air defense missile operators, the United States began to develop some target aircraft that could imitate the performance of fighters and bombers at that time. The Ryan Aeronautical Company of the United States won a contract with the United States Air Force in 1948 and began to develop a high A subsonic, jet-propelled target drone, this is the well-known "Fire Bee" drone. Due to the successful design, mass production began in 1953, and 1280 early "Firebee" Q-2A and KDA types soon served in the United States Armed Forces and the Royal Canadian Air Force. As of 1984, a total of nearly 6,500 "Firebee" series target drones have been put into use.
At this stage, in addition to the United States, France, Italy, Australia, Canada, Israel, Japan, and Germany have also developed a variety of target drones. Therefore, for a long time, the drone is basically a synonym for UAV.
The development of unmanned target drones has also led to the development of key technologies such as remote control telemetry technology, flight control and guidance technology, small engine technology, launch and recovery technology, and special equipment for drones. In the development process of drones, drone technology has successively broken through the speed limit of low speed, high subsonic speed and supersonic speed, and also broke through the airspace flying limit of ultra-low altitude, low altitude, mid-high altitude and high altitude. Laid the foundation for the all-round development.
During the Cold War in 1960, the United States repeatedly sent U-2 manned reconnaissance aircraft to the former Soviet Union reconnaissance missile base. In May 1960, a U-2 high-altitude reconnaissance aircraft owned by the US Central Intelligence Agency was shot down by SA-2 air defense missiles in the airspace of the former Soviet Union. It was because of this incident that the United States decided to develop an unmanned reconnaissance aircraft. The US Air Force soon launched the "Special Air Vehicle" (SPA) program, which is an unmanned reconnaissance aircraft program developed on the basis of the "Firebee" unmanned target drone. In the summer of 1960, Shui On Company began to try to transform the "Firebee" into an unmanned reconnaissance aircraft with low radar detectability, longer range, and better maneuverability—147A. Later, it quickly improved to complete the range change. The long-distance 147B type; subsequently, based on the characteristics of the former Soviet Union’s air defense missiles, the famous 147D "Firefly" unmanned reconnaissance aircraft was successfully developed. The aircraft is equipped with an electronic intelligence module that can collect the signal characteristics of the SA-2 surface-to-air missile guidance system, and can be used to lure SA-2 surface-to-air guidance.
The missile radar is turned on to intercept its signal characteristics and forward it to the ERB-47 electronic warfare aircraft.
In the 2003 Iraq War, the U.S. military used more than 10 types of drones to support combat operations, more than three times the number of the Afghan War. These drones mainly included the Army’s "Hound", "Pointer" and "Shadow 200". "Unmanned aerial vehicles, the "Longan" and "Pioneer" drones of the Marine Corps, and the "Global Hawk" and "Predator" drones of the Air Force. The "Global Hawk" carried out several combat missions over Baghdad and collected more than 3,700 images. The "Predator" also destroyed multiple ground targets including air defense missile companies, missile launchers, Iraqi TV station radars and satellite facilities. These unmanned aerial vehicles played a great role in the war against Iraq, which marked the beginning of modern warfare into the stage of unmanned operations.
From March to May 2010, the United States successively piloted the HTV-2 "Falcon" hypersonic UAV and X-37B aerospace UAV. On May 20, 2015, at Cape Canaveral Air Force Base, the U.S. Air Force used Atlas-V rockets to send the X-37B into space again for the fourth in-orbit mission. Prior to this, in the third flight test from December 2012 to October 2014, the X-37B flew for a total of 671 days in orbit, which marked the beginning of the drone's move towards higher, farther and faster air. Tian field development. The picture shows the X-37B aerospace drone.
In the military field, the rapid development of unmanned combat aircraft and aerospace UAVs has gradually made UAVs a key force in the military equipment system and a strategic commanding height for maintaining national security. In February 2011, the U.S. Navy's X-47B unmanned combat aircraft successfully made its first flight at Edwards Air Force Base in California. In July 2013, the X-47B successfully achieved an interception landing on the USS George Bush, marking that the U.S. Navy has mastered the key technology for UAVs to take off and land on aircraft carriers.
The picture shows the U.S. Army's "Shadow 200" UAV. A UAV supervisor of the U.S. Army Ground Maneuvering Program said in an AAI statement that for field commanders, the "Shadow" system is "a life-or-death tool." ".
Since the 1990s, many countries have placed the development of drones in an important position, and investment has increased year by year. At present, 57 countries in the world have developed and developed UAVs, and nearly 1,000 types of UAV systems have been developed and developed, of which nearly 400 have become UAV products. The United States occupies the commanding heights of the development of UAVs. Israel started early and has its own characteristics and advantages in tactical UAVs and long-endurance UAVs. Russia has never relaxed the development and application of advanced technologies. European and Asian countries have also accelerated With the development of unmanned aerial vehicles, the development of unmanned aerial vehicles has set off a new climax worldwide.
1.4 The development trend of drones
With the development of unmanned aerial vehicle systems, unmanned aerial vehicles have expanded from unmanned aerial vehicles to nearby unmanned aerial vehicles, and then to unmanned aerial vehicles in space; the mission of unmanned aerial vehicles has expanded from single reconnaissance and surveillance to information countermeasures and communications. Relaying and other aspects are currently further expanded to
Fields such as precision strikes and air dominance operations; the technology of unmanned aerial vehicle systems has further developed in the direction of autonomous control, high survivability, high reliability, and interconnection. In terms of the current development trend of UAVs, the development direction of UAVs is mainly reflected in the following aspects.
(1) High altitude long endurance direction
In future wars, long-endurance drones, especially high-altitude long-endurance drones, will become an important supplement and enhancement method for reconnaissance satellites and manned strategic reconnaissance aircraft. Some countries have included it as a link in the major defense operations system of "military satellites, manned spacecraft, early warning aircraft, strategic missiles, and long-endurance UAVs". The implementation of strategic reconnaissance has become one of the important means of acquiring strategic intelligence. .
(2) Stealth direction
Stealth fighter technology has matured day by day, and the application of stealth technology to drones is also a general trend. The "Dark Star" stealth drone that the US military first developed is a high-altitude long-endurance tactical drone.
(3) Precision strikes and air dominance operations
In the 21st century, there will be unmanned combat aircraft that can penetrate deep into the theater of war and perform attack missions in highly dangerous battlefield environments. This aircraft can perform the tasks of existing bombers, fighter jets, armed helicopters and cruise missiles, becoming a new type of precision strike weapon system.
(4) Miniaturization and intelligence
Due to the simple and flexible operation of micro-UAVs, strong maneuverability and low-altitude flight advantages, with the needs of global counter-terrorism and special operations missions, countries attach great importance to the development of micro-UAVs. Moreover, with the development of electronic technology and control technology, future drones should be able to complete tasks semi-autonomously according to pre-set procedures, or even complete tasks completely autonomously from beginning to end.
(5) Near the space field
Near-space UAVs have unique advantages in continuous reconnaissance and surveillance of specific areas, communication relay, navigation, electronic warfare, missile defense, and space countermeasures. They are an important supplementary force for land, sea, air, and space equipment. Become the focus area of the world's weaponry development.
(6) Network formation flying
The fragility of UAVs and the limitation of load capacity determine that with the continuous expansion of applications and the continuous improvement of use requirements, multi-UAV networking and collaborative execution of tasks will be a good development path.
(7) Multiple fields and diversified directions
In addition to the wide application of UAVs in the military field, in recent years, there has also been a blowout trend in the civilian field. The types of UAVs have also developed in a diversified direction according to the expansion of their application fields. I believe that in the near future, there will be more and more complete drones that will play its unique role in all areas of society.
1.5 System composition of UAV
With the continuous development and improvement of UAV performance, UAV systems capable of performing complex tasks include the following sub-systems:
(1) Unmanned aerial vehicle subsystem: airframe, power unit, flight control and management equipment, etc.;
(2) Mission equipment sub-system: battlefield reconnaissance and shooting equipment, electronic countermeasure equipment, communication relay equipment, attack mission equipment, electronic technology reconnaissance equipment, nuclear, biological and chemical detection equipment, battlefield measurement equipment, target equipment, etc.;
(3) Measurement and control and information transmission subsystem: radio remote control/telemetry equipment, information transmission equipment, relay and forwarding equipment, etc.;
(4) Command and control subsystem: flight control and management equipment, integrated display equipment, map and flight track display equipment, mission planning equipment, recording and playback equipment, intelligence processing and communication equipment, other intelligence and communication information interfaces, etc.;
(5) Launch and recovery subsystem: equipment or devices related to launch (take-off) and recovery (landing), such as launch vehicles, launch boxes, boosters , landing gear, recovery parachutes, arresting nets, etc.;
(6) Support and maintenance subsystem: basic-level support and maintenance equipment, base-level support and maintenance equipment, etc.
The unmanned aerial vehicle subsystem is the carrier of the mission. It carries remote control and telemetry equipment and mission equipment to reach the target area to complete the required mission. The measurement, control and information transmission subsystem realizes the remote control of the UAV through the uplink channel; and completes the remote measurement of the UAV state parameters through the downlink channel. And return the intelligence information obtained by reconnaissance. The mission equipment sub-system completes the required tasks such as reconnaissance, calibration, electronic countermeasures, communication relay, attack on targets and drones. The command and control sub-system completes tasks such as command, battle plan formulation, task data loading, ground and aerial working status monitoring and control of the UAV, as well as flight parameters and intelligence data recording. The launch and recovery sub-system completes the launch (take off) and recovery (landing) tasks of the UAV. The support and maintenance sub-system mainly completes the routine maintenance of the system, as well as the status test and maintenance of the UAV.
1.6 The basic composition of drones
Generally speaking, UAV has six major components: aircraft frame, flight control system, propulsion system, remote control, remote control signal receiver and pan/tilt camera.
1. Aircraft frame
The size of the flying platform depends on the size of the propeller and the volume of the motor (motor/motor): the longer the propeller, the larger the motor, and the larger the rack size. The frame is generally made of light materials to reduce the payload of the drone.
2. Flight Control System
Flight Control System (Flight Control System) is abbreviated as flight control, and generally has built-in sensors such as controller, gyroscope, accelerometer and barometer. The drone relies on these sensors to stabilize the body, and with GPS and barometer data, the drone can be locked at a designated position and altitude.
3. Propulsion system
The UAV's Propulsion System is mainly composed of propeller wings and motors. When the propellers rotate, they can generate a reaction force to drive the body to fly. An Electronic Speed Control (Electronic Speed Control) is installed in the system to adjust the speed of the motor.
4. Remote control
This refers to Remote Controller or Ground Station, which allows aerial players to control the drone's flight movements through remote control technology.
5. Remote control signal receiver
The main function is to allow the aircraft to receive remote control command signals sent by the remote control. A 4-axis UAV must have at least 4 channels to transmit signals in order to control the 4 groups of rotating shafts and motors respectively.
6. Gimbal Camera
At present, the aerial cameras used by drones, in addition to the cameras preset by drone manufacturers on the aircraft, some models allow users to assemble third-party cameras, such as GoPro Hero 4 action cameras or Canon EOS 5D series single-lens cameras. In recent years, some manufacturers have also advocated the use of M4/3 mirrorless single-lens (such as: Panasonic LUMIX GH4) for aerial photography.
The aerial camera is mainly installed on the aircraft through a gimbal. The gimbal is the most important part of the entire aerial photography system. Whether the image of the aerial video is stable or not depends on the performance of the gimbal. The gimbal generally has two built-in motors, which are responsible for the vertical and horizontal swing of the gimbal, so that the camera mounted on the gimbal can maintain the rotation axis unchanged, so that the aerial image will not shake due to the vibration of the aircraft.
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