Unmanned Aerial Vehicle (UAV), also known as unmanned aerial vehicle or remotely piloted aircraft, is a non-manned aerial vehicle controlled by radio remote control equipment or operated by preprogrammed. The drone is maneuverable and flexible. It is small in size and light in weight and can be transported and carried at any time. It has low requirements for takeoff and landing and is ready to fly. UAVs generally fly smoothly at low altitudes under the clouds, making up for the shortcomings of satellite optical remote sensing and ordinary aerial photography that are often blocked by clouds. In addition to its broad military application prospects, the use of drones to replace manned aircraft to perform high-risk missions is also an important development aspect of the international aerospace industry. Especially in the international local wars in recent years, drones have been used in large numbers. It is foreseeable that the use of drones will become larger and larger in the future battlefields, and has become the focus of weapons and equipment development in all countries of the world. At the same time, as an air vehicle with high technology content, good performance and broad development prospects, the UAV can also complete disaster prevention and disaster reduction disaster assessment, geological survey aerial photography, police highway inspection, forest fire prevention, maritime affairs in the civilian field. Patrol, large-scale show performance aerial photography and other tasks.
In the field of drones, the "Dajiang drone" has risen, and drones have quickly entered the consumer field. UAVs have become adult toys that everyone can consume. Thousands of yuan can buy a superb performance. Machine, "Wang Feng, Zhang Ziyi's engagement ceremony on the drone to send a wedding ring" and other hot events, with the media hype, the UAV manufacturing industry is also full of capital figure, there are hundreds in Shenzhen Drone manufacturers, just like the days when cottages prevailed, as long as you have demand, you can quickly find a drone program you need in Shenzhen, and drones will slowly become one of the important equipment for family self-driving travel. .
According to statistics, 300,000 drones will be sold every month in the world. Last Christmas, only 1 million UAVs were sold in one country in the United States. UAVs have quickly entered the home market.
UAV control link introductionHow to control the drone? The drone uses a wireless link for remote control and video data backhaul. More than 90% of the drones operate in the ISM band (2.4 GHz), including frequency hopping, Wi-Fi, etc., where the control link uses:
Commonly used frequencies are the ISM band: 2.4 GHz, 5.8 GHz
Rarely used: 433 MHz, farther than 2.4GHz
Use a small amount of outdated remote control bands: 27 MHz, 35 MHz, 72 MHz (using PCM or analog encoding)? These drones have gradually disappeared.
The data link uses:
Video data streams are typically transmitted over 2.4 GHz/5.8 GHz (ISM band) using WiFi or analog PAL/NTSC
Safe flight uses related technologies:
Safe flight through redundant control systems (eg, wireless remote control, and GPS-based "fail-safe" mode)
UAVs have different control methods according to price levels. For example, some low-cost drones use Bluetooth technology (ISM 2.4GHz); most drones use Wi-Fi or frequency hopping (ISM 2.4GHz); some also have high-end The drone uses satellite navigation based on a preset path.
UAV "black fly" hazardThere is a blind spot in the supervision of drones in China, and the large-scale use of drones poses hidden dangers to public safety. More and more drones that were originally used for legitimate purposes are used for criminal purposes. The public has become increasingly aware of the dangers that drones can cause. UAVs can smuggle drugs; drones can pry into privacy/technology; drones can affect civil aviation – close to collisions; drones can occur in sensitive areas, critical locations, and government facilities; drones can even shoot automatically... ...
In the past two years, a number of unmanned aerial vehicles have been suspended in the country, which has become a "stealth killer" for civil aviation flights. At the end of 2013, a Beijing company did not have aerial photography qualifications and did not apply for airspace, and caused aerial navigation and landing delays. In 2017, Zhejiang Xiaoshan Airport and Mianyang Airport, the Chengdu airport was caused by unidentified drones, resulting in hundreds of aircraft delays, tens of thousands of people stranded, and the losses to the country and the people were hundreds of millions.
The biggest problem with drones is "black fly" and "pilot" does not have a qualification certificate. The 2015 China Civil Aviation Pilot Development Annual Report pointed out that the total number of Chinese drone driver certifications last year was only 2,142. In fact, there are more than 20,000 drones in China, and the number of flight operators is far more than 2,142. The phenomenon of “black fly†is serious and there is a huge risk of causing safety accidents. The Civil Aviation Authority began to crack down on drone black flying in 2016. The problem, but as more and more drones enter the ordinary family market, the effect has not yet been effectively seen.
UAV monitoring and counteringThe main means of monitoring UAVs in various countries are divided into two modes: administrative supervision and technical prevention.
In order to strengthen the management of drones, Japan has implemented a new "Air Law" since December 10, stipulating that areas where population is concentrated are prohibited from flying drones, preventing drones from causing accidents or being used for crimes. Offenders will A fine of 500,000 yen is imposed; the United Kingdom also regulates the use of drones. Article 166, paragraph 3 of the Air Law stipulates that small drone operators must be able to see drones all the time, Fully controlled, keep a certain distance from other aircraft, people, vehicles and buildings during flight to avoid collisions.
From a technical point of view. At present, foreign UAV anti-theft technologies generally have signal interference, radar detection, laser shot down, and integrated technology.
(1) Signal interference: The drone needs to know its precise position when working, but the drone itself cannot obtain accurate coordinate data. Therefore, the GPS receiver is installed on the drone, and the GPS satellite navigation system and inertial navigation are adopted. The system is combined in a flight control mode. The signal interference technology is based on the GPS signal receiver that affects the drone, so that it can only rely on the gyroscope-based inertial navigation system, and cannot obtain sufficiently accurate self-coordinate data. American DroneDefender radio gun strike technology Batfeoe, a non-profit development agency in Ohio, recently introduced a DroneDefender anti-UAV device. The DroneDefender looks like a rifle, with a white rod antenna mounted on the front of the front of the unit. This device uses non-destructive technology and is the first dedicated device that can move, accurately and quickly prevent suspicious drones from approaching. The user simply “points down†the target by pointing it to the drone in the air and snapping the trigger. The device is only effective for real-time remote-controlled drones or drones that rely on GPS navigation (such as common quadcopters and six-axis aircraft), with a range of about 400 meters; European Airbus Group anti-UAV system, Airbus Defense and Aerospace developed an anti-UAV system that uses interference techniques to interfere with the frequency of the target signal without affecting signals at other frequencies around it. The system can detect and carry out attacks on illegal drones flying in disputed areas, while minimizing the impact on other objects. The system is equipped with signal analysis technology and interference functions, and is equipped with radar, infrared camera and orientation instrument. It can detect drones within 5 to 10 kilometers and can judge the threat of drones. Based on the huge information base information, the system can also analyze the signal of the drone. Once the problem is found, the system will cut off the connection between the drone and its operator through the interference station, and then the orienter will track the unmanned person. The specific location of the operator is convenient for the implementation of the arrest operation. The system has been tested several times in the company and has also been shown to German and French customers.
(2) Radar detection: Sweden's "Giraffe" radar system, according to the US H JSJane's defense and security intelligence website reported on September 16, 2015, Sweden Saab company demonstrated its "WestFreuqh" shooting range in Scotland. The ability of the Giraffe's agile multi-beam (AMB) radar system to detect small targets at low and low speeds. The test, called "Bristol 15", shows the radar's powerful detection capability (ELSS) for low-altitude, low-speed small targets, which can perform anti-UAV systems while performing all air surveillance missions ( UAS) combat mission. In the "Bristol 15" test, the radar cross section is accurate to 0.001 square meters, which enhances the detection of low-altitude, low-speed small targets, automatically identifies low-altitude, low-speed small targets and tracks them, and amateurs operate at low speeds. Small four-axis unmanned aircraft system. The “Giraffe†Agile Multi-Beam Radar System is a family of two- or three-dimensional G/H-band passive electronically scanned array radars for terrestrial and oceanic applications that provide coastal surveillance capabilities to fixed-wing aircraft, helicopters, ground targets, and interference. Classification and tracking of aircraft and ballistic targets; Italy's "Falcon Shield" system on September 15, 2015, at the British Military Equipment Exhibition DSEI in London, England, the Italian company Finmeconica Group SeIex ES company demonstrated its research and development The "Falcon Shield" drone system. The system is capable of locating, identifying and controlling remote micro or small drones that pose a threat to public safety or private, the so-called “rogue dronesâ€. According to the company, the market value of the device could be hundreds of millions of pounds; the Falcon Shield system uses cameras, radar and advanced electronics to monitor the signals received and transmitted by the drone, tracking it and determining its type. . Once the target is locked, the Falcon Shield uses its proprietary technology to control the drone and even crash it. Compared with other companies that use electronic warfare to destroy drones, the advantage of Falcon Shield is that it can effectively avoid damage to surrounding buildings and other environments while accurately shooting down "rogue" drones. In addition, when transmitting radio signals to control drones, it will not hinder the transmission of other important signals such as emergency services and even mobile communications; Mexico's JAMMER defense system, JAMMER, Mexico, developed the Tamce Bloqueador Direccional AnTI-Drone defense system for families. air defense. The system's interference power is 20 watts, which can suppress hundreds of milliwatts of drones. After the switch is activated, the jammer can interfere with the 2.4G and 5.8G signals. For most consumer-class drones, the remote control signal and the image transmission signal will be lost. After the signal is lost, the drone can only return or the original Landing; US Drone Shield monitoring system Drone Shield, a manufacturer of UAV detection systems in the United States, has developed a technology that uses radar or a microphone to monitor drones. It has a built-in database of Raspberry Pi, signal processor, microphone, analysis software, and drone sound characteristics. By monitoring the sound of the surrounding environment, it is determined by sound comparison whether there is a drone. Alerts via email or text message when there is a drone nearby. In principle, early warning technology is not difficult, so the accuracy of monitoring and low false alarm rate are very important. In this regard, Drone Shield has its own patented technology. It is reported that the US authorities have used this system to provide security for prisons, sporting events and government buildings.
(3) Integrated technology: British anti-UAV defense system AUDS, in October 2015, the British Broadcasting Corporation, the US Homeland Security News Network, the Russian satellite network and other websites respectively for the UK fully integrated "anti-UAV defense system ( AUDS)" reported. The system, commonly known as the EMI ray gun, was developed by three UK defense technology companies (Blighter Surveillance Systems, Chess Dynamics and Enterprise Control Systems) to detect, track and destroy small and large drones. The system can be turned on 24 hours a day, fully automatic operation. First, radar and optical instruments (ie radar detection systems) are used to search for drones. When the radar or optical system detects the target, the dynamic positioning and video tracking system tracks, and then the directional RF interference system starts to work, transmitting directional high-power interference. The radio frequency interferes with the drone automatic control system and cuts off the data connection or radio communication between the drone and the rear control center, so that the drone cannot fly autonomously, resulting in crash, forced landing or returning. The AUDS system is priced at approximately $1 million and can be installed on a vehicle platform for deployment to military front lines, remote borders or urban areas to perform anti-UAV missions. The system consists of three subsystems and a set of master control equipment. The three subsystems are radar detection system, dynamic positioning and video tracking system, and directional radio frequency interference device. Developed by Blighter, the radar detection system is said to detect targets with a reflection area of ​​0.01 square meters, with a maximum detection range of up to 8 km, and the selection of different antennas to achieve changes in pitch angle and horizontal rotation angle; dynamic positioning Developed by CHESS Dynamic, the video tracking system consists of a rotatable mechanical platform plus high-resolution cameras and thermal imaging cameras for video tracking, with optional optical interference to emit high-density beams; Developed by Enterprise Control Systems, it uses a high-gain quad-band antenna to align the target to emit radio waves, which can cause the wireless remote control unit operating on the C2 channel to malfunction. The drone that cannot receive the command can only circulate until the power consumption It crashed. According to the report, the system was first publicly released in May 2015 and tested in different terrains such as the wilderness and cities in Europe (such as the United Kingdom, France) and North America (such as the United States); Thales is equipped with Thales A combination of radar, sound image detectors, orientation meters, RF and video positioners and laser scanning devices was introduced. The suppression of illegal drones is done by kinetic weapons (artillery or sniper rifles), or by laser interference, selective interference, GPS spoofing, electromagnetic pulses, or by another device that interferes with the device. The drone is intercepted. Thales has conducted technical tests on anti-UAVs for 4-rotor drones and other small drones.
(4) Other technologies: Radio control uses a receiver to track and determine the drone, and uses a sufficiently powerful electronic signal to illuminate the drone to seize its radio control. During the operation, once the drone can't receive the signal, it will crash. By intercepting the transmission code used by the drone, the drone will be controlled and returned. The Federal Aviation Administration (FAA) and information technology company CACI have launched the SkyTracker system, which builds electronic boundaries around sensitive areas such as airports. CACI said the system can use drone radio lines to identify and locate drones flying in no-fly or protected airspace, as well as to locate drone operators. The CACI website mentioned: "The CACI system can accurately locate the black flying drone and distinguish other drones in the same airspace." CACI said that SkyTracker can also effectively prevent designated drones; microwave interference, Microwave weapons, also known as radio frequency weapons, use high-energy electromagnetic radiation to attack and destroy targets. Compared with laser weapons, microwave weapons have a long-distance effect, are less affected by climate, and are convenient for fire control. Military experts predict that with the continuous development of new technologies and new materials, microwave weapons will play more and more role. Russia's United Instrument Manufacturing Group has produced ultra-high-frequency microwave guns that can be used to help ground-to-air missiles "beech" attack drones and high-precision weapon electronics. The microwave gun has a range of more than 10 kilometers and can be mounted on a special platform to achieve 360-degree defense. In addition to being used for air defense, this weapon can also be used to detect the anti-microwave radiation capability of Russian military electronic systems. Acoustic interference, sonic interference technology is to use sound waves to make the gyroscope resonate and output error information. Causes the drone to fall. The researchers found that if the sound is strong enough (for example, 140 decibels), the sound waves can shoot down drones 40 meters away. South Korea announced in August 2015 a technique for shooting down drones with sonic interference gyroscopes. The researchers connected the drone to a very small commercial speaker that was about 4 inches (about 10 cm) from the gyroscope and then wirelessly controlled the speaker through the laptop. When the noise matched with the gyroscope was issued, an unmanned opportunity that was originally flying normally suddenly fell from the air. Of course, it is impossible to connect the speaker to the drone in a real attack scenario. This method is not really effective anti-UAV measures. The current difficulty lies in aiming and tracking, and may be used in conjunction with tracking radar in the future.
ViewWith the drones moving from military and industrial applications to mass consumption, the safety of drones has become increasingly prominent. The Chengdu airport’s event, the social impact of four small drones of less than 10,000 yuan to Chengdu Airport And the loss of economic efficiency is incalculable.
How to achieve the monitoring and counter-measure of drones has become a hot topic in the industry. Although China Civil Aviation has also commissioned mainstream drone manufacturers such as “Dajiang†to regulate the manufacture of drones and set sensitive no-fly zones. However, compared with the vast number of UAV manufacturing and sales markets, it is not enough to rely solely on UAV host manufacturers for monitoring and control. In some sensitive areas, UAVs are actively monitored and monitored, and certain counter-attack capabilities are built. The fundamental way to solve the problem is that there have been many research results in this field in foreign countries. As a manufacturing and powering country for drones, China is now paying more attention to the manufacturing and manufacturing of drones. The safety monitoring technology for drones is still in its infancy. How to build a mature and perfect UAV safety monitoring and counter-system is especially important for promoting the healthy development of the UAV industry in the future.
With the rapid development of the economy, drones have entered all aspects of life. Therefore, how to ensure the safe and effective operation of the drone and the harmonious coexistence with the existing aviation aircraft has become a relatively urgent need in real life. This will inevitably lead to a huge drone surveillance market. This area needs more and more investment to ensure that UAVs have early warning and counter-attacks in important areas such as airports in the development of the UAV industry. Ability to better solve the safety supervision problem in the context of universal application of drones.
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