OFweekRobotIn recent years, there have been more and more low-altitude and small aircraft (hereinafter referred to as “low, slow and small”) represented by light/ultra-light UAVs, multi-rotors, delta wings, model aircraft, and powered parachutes. Statistics show that in May, there were 19 incidents of drones affecting the normal operation of flights at airports in the southwest, northwest, and central and southern regions, which brought great inconvenience to safe operations and passenger travel.
In addition to threatening the take-off and landing of flights, “low, slow and small” may also cause harm to national security. In 2014, ten nuclear power plants in France encountered unidentified drones “stealing”; drones flew over the Blue House in South Korea many times and took close-up photos; on January 16, 2015, a “phantom” drone Breaking through the “world’s tightest defense network”, it crashed on the lawn of the White House in the United States; on April 22, a drone was found over the Japanese Prime Minister’s residence…
“The ‘low-slow-small’ aircraft has the characteristics of simple production, low cost, easy acquisition, strong remote control capability, and difficulty to be discovered and disposed of.” said Fan Guobin, deputy chief engineer of the Chinese Academy of Engineering Physics (hereinafter referred to as the Chinese Academy of Physics). .
Although the Civil Aviation Administration of China has carried out the real-name registration of drones since June 1 this year, experts pointed out that the “unintentional interference” of regular manufacturers and compliant users can be controlled, but the “black flight” of malicious people is hard to prevent.
In order to solve the problem of “low, slow and small” threats to security, the organization unit of the Chinese Academy of Sciences has successfully developed the “Low-altitude Guardian” series of laser interception systems.
Inadequate traditional means
According to Fan Guobin, “low, slow and small” generally has the following characteristics: low altitude – most of the flight heights are below 500 meters; slow speed – the flight speed is generally below 50 m/s; small target size – usually 1 square meter A large number of batteries are used as power, and most of them can fly more than 5 kilometers and carry a load of several kilograms. Most of them are autonomously controlled according to predetermined procedures.
“Low, slow and small” has a small geometric size and weak infrared characteristics, coupled with the complex background of the urban low-altitude environment, making early warning and tracking difficult. Even if radar and optoelectronic systems find it, due to the short distance, short warning time, strong maneuverability, and poor positioning accuracy, the use of modern air defense means combining missiles and anti-aircraft artillery is inefficient. It is a bit like hitting mosquitoes with cannons, and It also has the potential to cause collateral damage to the ground and people, making it unsuitable for use in urban environments and major events.
Therefore, the disposal of “low, slow and small” targets has always been a difficult point in security. It can be said that low-altitude security is a worldwide problem.
At present, the development of “low, slow and small” is extremely rapid, which makes it more and more likely that criminals will use it to cause illegal accidents. When “low, slow and small” pose a threat to the security of important areas or major event venues, the current general response methods mainly rely on snipers and rapid-fire guns to intercept, or rely on aerial nets or helicopters to capture in the air, and there is also radio frequency interference. devices, but these methods have a low success rate.
Lasers come in handy
The world’s first ruby laser was invented by American scientist Maiman in 1960. Since then, laser technology has developed by leaps and bounds.industrymedical, information science, biotechnology and military have been widely used.
Laser has the characteristics of good directionality. It does a good job of focusing light on a small area of the object. For example, the light of the flashlight we usually use is divergent, and the laser pointer used in lectures and classes is a single light, with a high degree of concentration. In addition, the laser has the characteristics of high illumination. The illumination intensity of the sun directly hitting the ground is generally hundreds of watts per square meter, while the illumination of the laser can reach several kilowatts per square centimeter.
Scientists use this feature to transmit and project high-power lasers to the target at a long distance, and through thermal ablation, destroy the target structure, thereby destroying or incapacitating the target.
“Low-altitude Defender” has bright eyes
On the basis of extensive research, in order to solve the hidden problem of “low, slow and small” aircraft, the scientific research team headed by Fan Guobin, deputy chief engineer of the Chinese Academy of Sciences, took advantage of long-term research on lasers to develop a low-altitude security service. “Low-altitude Guardian” high-tech system.
According to reports, the system independently proposed and realized a new configuration of the split-type combined laser system, breaking through the high-efficiency and high-quality laser synthesis technology, the rapid disassembly optical assembly technology, the one-key calibration of the coupling optical path, and the split design of the tracking turntable, etc. A series of key technologies realize the fast connection of optical, electrical, mechanical and thermal interfaces, and effectively solve the problems of deployment in various complex areas such as urban dense areas and high-rise building roofs; improve the trajectory prediction ability of targets with random disturbances, and achieve low Stable tracking of slow and small targets; establishes the spatiotemporal correlation criterion of true and false targets, effectively reducing the false alarm rate of automatic target extraction.
The “Low-altitude Guardian” system strikes the “low-slow-small” by emitting lasers, and its damage is mainly by ablating the surface materials and functional components of the “low-slow-small” to destroy its dynamic characteristics, energy system, flight control system, etc. , making the target incapacitated. When the laser radiation heating and the combustion heat release of the composite material work together, it will cause a large area of the flying wing or body material to be ablated and carbonized, resulting in a decrease in the strength of its structural material, which makes the “low, slow and small” unable to withstand the flight. Mechanical load; and when laser irradiation directly or indirectly ablates the energy system and flight control system, it will also cause the aircraft to have air disaster consequences.
According to the introduction of the system development unit, in actual use, the radar continues to search the airspace on a large scale. Once a suspicious target such as a drone is found, the target’s position information is sent to the “Low-altitude Guard”, and the “Low-altitude Guard” is guided to automatically capture and sustain the target. Track, and Display the target image on the command screen in real time. The command and control system judges whether the target enters the strike range according to the ranging information. When the target enters the strike range, the commander selects the aiming position, launches the main laser, and burns the key parts of the target until the target is reached. crash. After that, the system can switch to the duty state or immediately enter the strike state of the new threat target according to the task.
Strong mobile power on call
The “Low-altitude Guardian” system has a single set of transmit power of nearly 10,000 watts, and a low-altitude effective escort area of 12 square kilometers. After its deployment, it can accurately intercept a variety of fixed-wing aircraft with a radius of about 2.5 kilometers and a 360-degree airspace within 5 seconds. It is fast, accurate, silent, and free of collateral damage. According to reports, the “Low-altitude Guardian” has successfully completed many tests and demonstrations, and shot down more than 30 typical small aircraft such as fixed-wing, multi-rotor and helicopter, with a success rate of 100%.
In order to deal with “low, slow and small” more flexibly and effectively, the Chinese Academy of Physical Sciences has successfully developed the world’s first split-combined “low-altitude guard” system, which can be disassembled into several parts for manual handling, such as transporting to the roof, and then quickly assembled. At the same time, the system adopts the automatic protection design of light output to avoid accidental hit and accidental damage to the target. The system is equipped with infrared imaging tracking and has all-weather combat capability. In order to improve the autonomous operation capability of the system, the Chinese Academy of Physical Sciences has simultaneously developed a radar system for the “Low-altitude Guardian”, which can achieve effective monitoring and target guidance for “low, slow and small” targets, overcoming the large size and slow rotation of traditional radars. , the sensitivity is limited, and it cannot be deployed on high-rise buildings.
The split and combined low-altitude guard system has been successfully developed, effectively solving the problems of deploying various positions in dense urban areas and high-rise building roofs, and providing an important means for low-altitude security in cities and important core areas, and has been used in major tasks. It has played an important role and is the first system in the world with practical application.
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