Terminal control proximity fuze setting and firing system

Abstract

The application discloses a terminal control near bomb warhead fuze setting and detonating system and belongs to the field of electronic industry. The patent comprises a laser irradiator outside a cannon tube, a coding communication mechanism, a laser receiver arranged at the bottom of a cannon warhead, an electronic near explosion fuze in the cannon warhead and a search and fire control system. The system can detonate the ammunition near the enemy target by transmitting the coded laser from the launching platform or the independent fire control platform, so that the low-cost and widely-used air explosion ammunition precise near explosion control effect which is difficult to be considered in the known art can be realized.

Description

Technical Field

[0001] This invention relates to a high-precision, multi-functional, and low-cost ammunition proximity fuse setting and control system, belonging to the field of military industry. Background Technology

[0002] Currently, given that high-power laser air defense systems are still severely constrained by factors such as the large size of the power supply system, rain and snow, and battlefield smoke, small and medium caliber anti-aircraft guns have become the most effective means of intercepting and defending against various small and medium-sized drones and stealth cruise missiles.

[0003] Taking the AHEAD projectile as an example, the time fuze is the primary operating mode of the airburst fuze, and its timing accuracy determines the fuze's overall accuracy. An electronic time fuze consists of an oscillator, frequency divider, storage counter, electronic safety circuit, ignition circuit, interface and timing logic circuit, power supply, boost circuit, mechanical safety, and detonation sequence. In current technology, after the projectile is fired, as it approaches the muzzle, the electronic fuze performs several steps, including power supply activation, circuit initialization, and clearing relevant storage devices. Within tens of microseconds before and after the projectile leaves the muzzle, the detonation time (for a timing fuze) or detonation revolutions (for a revolution-counting fuze) is set in real-time into the fuze using an inductive setting method.

[0004] Modern small-caliber rapid-fire cannons are all automated artillery, and their rate of fire is gradually increasing. For example, the theoretical rate of fire for twin 25mm anti-aircraft guns is 800 rounds per minute, while the rate of fire for 30mm and 35mm rotary cannons can reach 6,000 to 10,000 rounds per minute. Because the velocity of each projectile must be measured in real time and the velocity information transferred to the projectile's fuse, very high demands are placed on the programmable airburst ammunition control hardware and the programming speed of the muzzle induction coil. Furthermore, the stability issues of the muzzle velocity measurement coil and programming coil make it difficult to achieve programmable airburst for ultra-high rate-of-fire rotary cannons with current technology.

[0005] From the working principle of AHEAD projectiles achieving high-precision strikes, the key technology is to measure the muzzle velocity of each projectile and set high-speed muzzle data. Because the muzzle environment during velocity measurement is a harsh environment of high speed, high temperature, and high pressure, achieving velocity measurement and setting under such conditions is very difficult. For small-caliber anti-aircraft projectiles, the maximum recoil impact overload during firing can typically reach 50,000G to 60,000G. On the external trajectory, the projectile's surface temperature rises due to continuous friction with the air, sometimes even reaching thousands of degrees Celsius. 0.5 seconds after firing, the domestically produced 35mm anti-aircraft gun projectile still has a rotational speed of 7333.6 rad / s, and the time for one rotation is approximately 750 × 10⁻⁶ rad / s. -6The time difference of 0.75 milliseconds (seconds) creates enormous radial centrifugal and inertial forces on the fuze. Under these conditions, the quartz crystal oscillator built into a typical industrial microcontroller, which determines the calculation of the main frequency and timing accuracy, cannot start or function properly because its working principle requires coupling mechanical and electrical oscillations. Similarly, various civilian and industrial sensors and chips (such as giant magnetoresistive sensors used to measure the number of rotations of a projectile) are difficult to use directly in projectile fuzes, or at least require custom development and special packaging processes to ensure they meet military-grade standards. All of these factors significantly increase the production cost of AHEAD ammunition.

[0006] Besides cost issues, existing AHEAD or 3P ammunition also suffers from additional accuracy problems in detonation point positioning due to their operating principles. For example, the muzzle velocity measuring coil required for AHEAD ammunition is susceptible to interference from external electromagnetic fields in actual combat. Furthermore, because the electrical dimensions of the velocity measuring coil cannot perfectly align with its geometric centerline, a certain target distance error occurs, leading to velocity measurement errors. This dimensional error further increases due to vibration and other factors during actual combat and continuous use. In contrast, the initial velocity measurement error and the slant distance error of a programmable ammunition within a certain range (e.g., the effective range of a 35mm anti-aircraft gun shell is typically 4km) are almost linearly related. For instance, if the relative intermediate error of the velocity measurement for an AHEAD anti-aircraft gun shell is increased from 0.4% to 0.2%, the deviation in slant distance at the detonation point will be reduced by up to 50%, effectively halving it. When the shell's position is already beyond the effective range of the launch platform, the projectile's trajectory begins to deviate significantly from a straight line, rendering the airburst fuse of existing programmable ammunition ineffective for proximity detonation. Meanwhile, electronic time-fuse systems inevitably contain execution errors, including: setting errors, loading time errors, setting reticle errors, timer start errors, and time base oscillator errors. These further reduce the accuracy and increase the cost of existing programmable airburst ammunition. In addition, the width of the fuze setting coil is very large, even approaching ten times that of the velocity measuring coil. The additional length and weight caused by the muzzle induction coil device and fuze programming setting coil required for AHEAD ammunition significantly increases barrel vibration, which is very detrimental to the accuracy of the artillery system and makes it susceptible to damage in combat due to impacts, repeated vibrations, and shock waves.

[0007] Besides being used in anti-aircraft guns and shipborne close-in weapon systems, existing airburst rounds can also be used as dedicated ammunition for anti-trenching and anti-fortification purposes. For example, the MK310ZRAVM-T programmable airburst round used in the US military's Mk44 "Bushmaster" autocannon can explode above trenches or behind bunkers, scattering a large number of fragments to directly kill soft targets such as infantry. Its airburst detonation point control principle is similar to that of AHEAD ammunition. The main difference is that, in order to reduce some costs, this type of ammunition uses a projectile rotation count fuse instead of the timing fuse used in AHEAD ammunition, and uses pre-fragmented fragments instead of tungsten alloy bullet heads.

[0008] It is easy to understand that the problem of high ammunition costs and the mutual constraint of airburst positioning accuracy is caused by the fact that in order to solve the problem of controlling the precise airburst position of ammunition, the artillery system chooses to adopt the design concept of "edge computing" in computer networks for programmable airburst ammunition. That is, the control system built into the shell itself needs to participate in and realize the automatic control principle of airburst.

[0009] Due to limitations in existing programmable airburst munitions, including their impact on launch platform cost, accuracy, and reliability, as well as the insufficient damage capability of proximity-guided warheads against anti-ship missiles and JDAMs with penetrating warheads, or their inability to intercept anti-ship missiles and glide bombs with penetrating warheads within their effective range, programmable airburst munitions, represented by AHEAD munitions, were gradually being phased out in air defense and ship close-in weapon systems before the rise of small and medium-sized UAVs. However, conversely, once the cost and range issues of programmable airburst munitions can be resolved, their combat effectiveness and cost-effectiveness can be significantly improved.

[0010] To address the cost and performance issues of programmable airburst bombs, Wang Benqing of Nanjing University of Science and Technology proposed a scheme in his 2006 master's thesis, "Research on the Principle of Semi-Active Laser Proximity Fuze for Small-Caliber Anti-Aircraft Guns," which utilizes an anti-aircraft gun launch platform to emit an coded target-illuminating laser. The distance between the projectile and the target is determined by comparing the shape and size of the diffuse reflection pattern of the laser emitted by the target. More specifically, the anti-aircraft gun projectile uses multiple laser receivers surrounding the projectile body to detect the diffuse reflection laser pattern on the target surface. When the projectile detects a target diffuse reflection pattern with a diameter of 3 meters and a central dark area the size of a set annular eclipse shape, it indicates that the projectile is inside the illuminating laser column. At this point, the laser illuminator, the projectile, and the target will be aligned and within a set distance, allowing for detonation. The detonation principle of the anti-aircraft gun projectile is similar to that of an active laser-guided airburst bomb, which continuously calculates the real-time distance between the bomb and the ground by measuring the size of the diffuse reflection projection pattern to determine when to detonate. The problem with this approach is that, limited by the size of the small-caliber shell, the performance of its laser proximity fuse is limited. Even without considering any actual errors and assuming the target is a sufficiently large, perfectly diffuse reflective plane, its theoretical maximum ranging accuracy is approximately 8 meters, which is barely adequate within the maximum kill radius of a 37mm high-explosive anti-aircraft shell (8 meters). Furthermore, setting up multiple laser receivers around the shell's circumference and performing image analysis within the shell increases shell cost, reduces proximity reliability, and decreases propellant charge. In other words, this technical solution, derived from the principle of active laser-guided munition ranging, suffers from severe reliability issues in actual combat due to factors such as atmospheric smoke interference with the laser signal, the accuracy of the laser transmitter and shell fuse, and the accuracy of the target's diffuse reflective image (e.g., the target is not a perfectly diffuse reflective plane). Moreover, this proximity ranging principle cannot effectively detect and attack small to medium-sized UAVs with a cross-sectional area less than 7 square meters (1.5 × 1.5 × 3.14 = 7.065 square meters) facing the shell, which greatly limits the application range of this type of self-ranged airburst munition. This type of problem remains unsolved due to limitations in technical principles.

[0011] Currently, publicly available information shows that the Chinese military has only adopted programmable proximity explosives on two active-duty equipment units: the PG-99 twin 35mm anti-aircraft gun and the PGZ-09 self-propelled anti-aircraft gun. Other platforms use them only as optional equipment. Although the Nanjing University of Science and Technology (NJUST) technology adopted by the PLA is closer to the US "Bushmaster" programmable airburst bomb than the Swiss Oerlikon AHEAD technology, it still faces problems such as relatively high cost and limited application. In conclusion, it is still necessary for my country to develop a new technological approach for proximity explosive weapon systems that are cheaper, more reliable, and more versatile.

[0012] Finally, let's supplement the current publicly known technical approaches to laser guidance and proximity bombing. These approaches are mainly divided into three categories: active laser guidance / proximity bombing, semi-active laser guidance / proximity bombing, and laser beam-riding guidance. Active laser guidance / proximity bombs emit positioning or ranging lasers from the bomb itself, while semi-active laser guidance / proximity bombs emit lasers from the launch platform or guidance equipment. Because both require receiving diffusely reflected laser signals from the target, the laser receiving window on both types of bombs is located at the front end or near the front sidewall. Laser beam-riding guided missiles, on the other hand, install the laser receiver at the tail of the missile. A rotating encoded laser transmitter at the rear of the missile continuously emits a laser information field cone encoded by a rotating modulation disk, containing spatial positioning information, to control the missile's flight trajectory in real time and correct any deviations. The laser cone with the laser information field only contains positioning data on the cross-section of the cone, but does not include the missile's own identification code or detonation time information. In other words, the laser is only responsible for trajectory guidance; laser beam-riding guided missiles are essentially impact bombs. All three technical approaches have significant limitations in terms of functionality and application scope. Summary of the Invention

[0013] The purpose of this invention is to provide a high-precision, low-cost ammunition proximity fuse setting and control system, belonging to the military industry, to solve the problems of high cost of programmable proximity shells and poor reliability of muzzle programming equipment under the existing technology, which also affects the accuracy of artillery.

[0014] To achieve the above objectives, the technical solution of this invention is as follows: A coding communication mechanism between the search and fire control system and the projectile is installed outside the gun barrel (unlike the AHEDA and 3P technical routes which use a programming coil at the muzzle). Its function is to facilitate data communication between the projectile and the search and fire control system, exchanging the projectile's unique digital identification code (hereinafter referred to as the projectile identification code) set in the projectile's electronic fuse. For both the search and fire control system and the projectile, the projectile identification code is unique and non-repeating for each projectile in a volley or in each battle. This projectile identification code can be generated by the projectile manufacturer, by the logistics and warehousing unit, or automatically generated by the search and fire control system before or after firing. More specifically: When affixing NFC or RFID tags to the shell casing, the artillery or shell feeding / loading mechanism should be equipped with a reader capable of reading the electronic tags, which then transmits the shell identification code to the search and fire control system. Alternatively, barcodes or QR codes (which can be multiple independent barcodes or form a ring around the shell) can be affixed or printed on the shell casing, and the shell feeding / loading mechanism should be equipped with a camera or scanner capable of reading the barcodes or QR codes, transmitting the shell identification code to the search and fire control system. Conversely, the search and fire control system can also generate a shell identification code and write it to the shell's electronic fuse via wireless near-field communication or coded optical signals. More specifically, an induction coil or signal antenna, along with corresponding filtering and digital-to-analog conversion signal processing circuits, can be installed in the electronic fuse of the projectile. Before loading, an identification code can be written to the projectile using a coil installed on the loader or added to the muzzle, or a handheld electromagnetic induction signal transmitter. This eliminates reliability and interference issues associated with setting the airburst time using an induction programming coil at the muzzle. Alternatively, a laser receiver can be installed on the projectile, and an coded laser transmitter connected to the search and fire control system can write the projectile's identification code into the internal electronic fuse before firing. However, these two methods of writing the projectile's identification code through the search and fire control system are not preferred solutions and are only disclosed as feasible embodiments in this patent. This is because the limited internal space of the projectile makes it unsuitable to install a large-capacity battery to achieve long-term standby of the projectile's electronic fuse; therefore, a design scheme that activates the electronic fuse battery for coding before firing is not advisable. Because the shell's identification information needs to be pre-written into the fuse's built-in memory, the proximity fuse must be powered on before firing to activate the internal microcontroller and data read / write module to meet the data writing requirements. This is detrimental to the reliability and storability of the built-in battery, affecting the reliability and storage time of the shell's proximity fuse. A more appropriate solution is to assign a shell identification code to the electronic fuse after firing. A detailed analysis of this solution is as follows: The system should ideally be equipped with a coded laser illumination system that can be aimed directly at the gun muzzle. A laser receiver should be placed at the bottom of the projectile's warhead. This allows the coded laser illumination system to immediately illuminate the receiver at the bottom of the projectile's warhead before and after the projectile leaves the barrel, writing the projectile's coded data, set by the fire control system, into the electronic airburst fuse inside the projectile. This coded data is unique and non-repeating for each projectile in a volley or in each battle. The artillery's fire control system uses radar, electro-optical detection systems, or velocity measurement systems to measure velocity and perform trajectory calculations. When one or more projectiles are sufficiently close to the target, the coded laser illumination system points at both the projectile and the target, firing the projectile's coded data at the closest projectile. Simultaneously, the laser receiver at the bottom of the projectile's warhead receives and compares the laser coded data. When the projectile's electronic airburst fuse confirms that the laser coded data, after photoelectric conversion, filtering, and signal amplification, is indeed the given data written at the time of leaving the barrel, or the correctly encrypted data corresponding to the given data after specific calculations, it immediately detonates the projectile, thereby destroying targets near the projectile. It should be emphasized that, based on the principles of structure and function, it is easy to deduce that the gun barrels mentioned in the text also include recoilless gun barrels, rocket launcher tubes, rocket launcher tubes, or grenade launcher tubes, and the projectiles mentioned also include rockets and grenades.

[0015] More specifically, the terminal control proximity explosive fuse setting and detonation system of the present invention, in addition to the artillery itself, may also include a set of coded laser illumination systems. This coded laser illumination system consists of one or more sets of coded laser illuminators, at least one of which is installed in a position that ensures its laser beam far-field divergence angle (for ease of memorization and simplification, this technical term will be referred to as laser divergence angle below) can encompass, or in other words, the laser field cone can cover the tail of the projectile before and after it leaves the barrel. This set of coded laser illuminators capable of covering the tail of a directly fired projectile can be attached near the muzzle of the artillery, or fixed to the turret or outer shield of the artillery platform to move in elevation and depression with the artillery, or mounted on a rotatable elevation platform structure to ensure that the coded laser illuminator is aligned with the muzzle when the artillery fires, and that the emitted coded laser illuminates and covers the tail of the projectile at the moment of exiting the barrel.

[0016] The coded laser illumination system also includes at least one coded laser designator capable of overcoming the curvature of the ballistic trajectory caused by factors such as gravity and wind, and ensuring that the coded laser designator remains pointed at the target even when the turret or gun barrel is tilting or rotating to obtain the lead of the ballistic trajectory. This laser designator can be mounted on a fixed mechanism by increasing the laser divergence angle, or mounted on a slewing and tilting mechanism (or "follow-up mechanism"), to ensure that the emitted coded laser illumination can always illuminate the target of the artillery system. When it meets the needs of actual combat (such as when this system is applied to weapons with short range and low rate of fire such as grenade launchers, rocket launchers, and recoilless rifles), it can also be combined with the laser designator mentioned above for illuminating the base of the projectile before and after it leaves the barrel, sharing a single set of equipment. By increasing the laser divergence angle, it can compensate for the target displacement lead in the projectile's flight path, the deviation between the projectile's curved trajectory and its orientation when it leaves the barrel.

[0017] The terminal control proximity fuse setting and detonation system of this patent also includes a laser receiver installed at the bottom of the projectile and an electronic proximity fuse connected to the laser receiver. The laser receiver comprises a lens that transmits laser light and a photoelectric conversion element, such as a photodiode or phototransistor, covering the lens to convert the coded laser light illuminating the laser receiver into a pulsed electrical signal. To prevent interference from external natural light and battlefield illumination light on the photoelectric conversion element, the lens covering the laser receiver should be coated or plated with one or more bandpass filter films. This effectively shields the lens from light of wavelengths other than the coded laser light, reducing the workload of the back-end filtering and decoding circuitry. It should be noted that the description of the laser receiver being installed at the bottom of the projectile is for simplification of the principle explanation and also includes installing the laser receiver on the tail fin of the rocket facing the launch platform.

[0018] The electronic proximity fuse includes a power supply module, a filtering and amplification circuit module, a shaping and decoding circuit module, a signal processing, storage, and calculation module, a detonation module, and an electric detonator (including fuse). Delayed self-detonation fuses and piezoelectric ceramic impact fuses can also be added to the electronic fuse as needed. Of course, in the prior art, these modules can be given other names, or multiple modules can be combined into one. For example, the filtering and amplification circuit module and the shaping and decoding circuit module can be equivalently combined and called a signal processing module, etc., as equivalent substitutes. Therefore, changes in the combination or name of the modules, rather than changes in their essential functions, do not affect the scope of protection of this patent. The function of the electronic proximity fuse is that after the projectile leaves the barrel, the laser receiver receives the first coded laser beam projected by the coded laser irradiation system and converts it into an electrical pulse signal, which is then transmitted to the electronic fuse. The power supply module of the electronic fuse is preferably a chemical battery, which is activated and stabilized with a large acceleration overload and centrifugal force before the projectile leaves the barrel, ensuring that the electronic fuse of the projectile has a stable power supply upon leaving the barrel. Chemical battery technology was first used in World War II to power the VT radio proximity fuses of US Navy naval guns, and it is now quite mature. At this point, the filtering and amplification circuit module filters and amplifies the electrical pulse signal transmitted by the laser receiver. The shaping and decoding circuit module performs secondary filtering on the analog signal from the amplification and filtering circuit modules, converting it into a digital signal, and then transmits it to the signal processing, storage, and calculation module. The signal processing, storage, and calculation module stores the initially obtained digitized encoded laser signal in the microcontroller and, after a certain period, commands the detonation module and electric detonator to open the fuse of the projectile. It is important to emphasize that the stored signal code should be unique within a single shot or a battle, and is bound to that projectile as its identification code.

[0019] When the shell finally approaches the target and reaches the detonation distance threshold, the artillery's search and fire control system determines this time point through fire control radar, the electro-optical detection system targeting the target, or shell trajectory prediction calculations. It then transmits the corresponding coded laser to the pre-aimed coded laser designator via a data link, targeting both the target and any shells near the target location. To facilitate differentiation and understanding of the two different laser codes, this coded laser will be referred to as the detonation code below. For the system of this patent, the identification code can be the same as the detonation code, and the two can also be converted based on various encryption algorithms. Once the shell receives the correct detonation code, the electronic fuse confirms the code's correctness and detonates the shell to carry out a proximity attack.

[0020] More specifically, when the radar controlling the artillery is an advanced radar such as millimeter-wave radar that can simultaneously detect targets and projectiles (such as the millimeter-wave radar of the Type 1130 close-in weapon system), the relative distance between the projectile and the target, as well as the specific moment when the detonation threshold is reached, can be measured and calculated by the radar and fire control system. Then, the coded laser illuminator emits a detonation code to detonate the projectile.

[0021] When an artillery system lacks an advanced radar system capable of tracking projectiles due to cost considerations or the need for radar concealment, a tracer tube (or even tracer tubes of different colors installed at intervals and in cycles between projectiles in a continuous ammunition belt) or an illuminating LED can be installed at the tail of the projectile to highlight and distinguish the images captured by each projectile. The image processing algorithm of the binocular camera or camera array of the photoelectric system is used to measure the distance and relative distance between the target and the projectile, calculate the detonation time, and then launch a detonation code to detonate the projectile.

[0022] When artillery systems cannot be equipped with radar and electro-optical detection systems due to cost, size, or weight constraints (such as on individual grenade launchers, recoilless rifles, and rocket launchers), the initial velocity of the fired ammunition can be determined (or the fire control system can estimate the initial velocity using pre-set propellant temperature). Then, based on the initial velocity, the fire control system calculates the target distance and the deceleration curve of the projectile due to range and elevation angle. After determining the flight time and confirming that the distance between the projectile and the target has reached a set threshold, the system controls the coded laser illumination system to fire a detonation code to activate the electronic fuse, achieving a proximity-based airburst. In this case, the velocity measurement components for the projectile can be muzzle coil velocity measurement, eddy current velocity measurement, or laser velocity measurement, all of which are mature and well-known technologies in the military industry.

[0023] The beneficial effects of this invention are: it solves the problems in the prior art where programmable smart airburst bombs and proximity bombs are difficult to miniaturize, have limited applications but are expensive, and the implementation schemes will compromise the accuracy of the artillery itself. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the module structure of the present invention; in the figure: 1 target; 2 projectile; 3 coded laser irradiation system; 4 artillery; 5 search and fire control system; 6 laser receiver.

[0025] Figure 2 This is a feasible embodiment of the present invention; in the figure: 1 target; 2 projectile; 3 coded laser irradiation system. Detailed Implementation

[0026] The following is a detailed explanation with reference to the accompanying drawings.

[0027] This system can either attach a near-field communication electronic tag to the shell 2, with the artillery 4 or the shell feeding or loading mechanism equipped with a card reader capable of reading the electronic tag on the shell 2, and the card reader transmitting the shell 2's identification code to the search and fire control system 5; or attach or paint a printed barcode or QR code to the shell 2 or the shell casing, with the shell feeding or loading mechanism equipped with a camera or barcode scanner capable of reading the barcode or QR code, transmitting the shell's identification code to the search and fire control system 5 during feeding or loading. In both of these schemes, the corresponding electronic tag or image-coded shell identification code should be pre-written into the electronic fuse inside the shell by the manufacturer or logistics storage unit. Conversely, the search and fire control system 5 can also generate the shell 2's identification code and write it into the shell 2's electronic fuse via wireless near-field communication or coded optical signals. More specifically, an induction coil or signal antenna, along with corresponding filtering and digital-to-analog conversion signal processing circuits, can be installed in the electronic fuse of shell 2. Before loading, a detonation code writing coil can be added to the loading machine or muzzle, or a handheld electromagnetic induction signal transmitter can be used to write the identification code to the shell. Alternatively, a laser receiver can be installed on shell 2, especially on the side of the warhead. Then, an coded laser transmitter connected to the search and fire control system can write the shell's identification code into the electronic fuse of shell 2 before firing. Because the identification information of shell 2 needs to be written into the fuse's built-in memory beforehand, this means that the proximity fuse must be powered on before firing to activate the internal microcontroller and data read / write module to meet the data writing requirements. However, considering the need to reduce the complexity of the internal electronic fuse structure of shell 2, the battery size, and to improve the execution speed, automation, and reliability of the entire operation process, these pre-firing programming schemes are not preferred options and are disclosed here only as alternative feasible solutions.

[0028] The optimal solution is to install a coded laser illumination system 3 outside the barrel of the artillery 4, and a laser receiver 6, which can be aligned with the muzzle, at the bottom of the projectile 2's warhead. After the projectile 2 leaves the barrel, the coded laser illumination system 3 immediately illuminates the laser receiver 6 at the bottom of the projectile's warhead, writing the projectile's coded data, set by the fire control system, into the electronic airburst fuse inside the projectile 2. This coded data, serving as the projectile's identification code, should ideally be unique and non-repeating for each projectile 2 in a volley or in each battle. When applied to close-to-medium range combat equipment such as rocket launchers or recoilless rifles, the laser illumination system 3 can preferably be an infrared laser or an ultraviolet laser to avoid visual detection by enemy soldiers.

[0029] The fire control system of artillery 4 can detect targets using radar or an optoelectronic system, measure velocity, and perform ballistic calculations. When one or more shells 2 are sufficiently close to target 1, the coded laser illumination system 3 points to both shell 2 and target 1, emitting a shell detonation code laser data signal to the shell 2 closest to target 1. Simultaneously, a laser receiver 6 at the bottom of the shell 2's warhead receives and compares the detonation code data. When the electronic airburst fuse of shell 2 determines that the code, after photoelectric conversion, filtering, and signal amplification, matches the given data written at the time of muzzle exit, at the factory, or during loading, it immediately detonates the shell, thereby destroying target 1 near shell 2. It should be emphasized that the gun barrel 4 mentioned in this text also includes recoilless rifle barrels, rocket launcher tubes, rocket launchers, or grenade launcher tubes; therefore, the shell 2 also includes rockets or small-caliber grenades.

[0030] More specifically, the terminal control proximity explosive fuse setting and detonation system of the present invention includes, in addition to the artillery 4 itself, a set of coded laser illumination system 3. This coded laser illumination system 3 consists of one or more sets of coded laser illuminators, with at least one set installed in a position that ensures its laser divergence angle can encompass, or in other words, the laser field's light cone can cover the tail of the projectile 2 at the moment of ejection from the barrel. This set of coded laser illuminators capable of covering the tail of the projectile 2 can be attached near the muzzle of the artillery 4, or fixed to the turret or outer shield of the artillery platform, moving in elevation and depression with the artillery 4. By changing the lens curvature to increase the far-field divergence angle of the refracted laser beam, it compensates for the lead of the target 1 in the flight path of the projectile 2 and the deviation between the trajectory curvature of the projectile 2 and its orientation upon ejection from the barrel. Alternatively, it can be mounted on a rotatable gimbal structure to ensure that the coded laser illuminator is aligned with the muzzle when the artillery 4 fires, and that the coded laser of the projectile 2's identification code can illuminate and cover the tail of the projectile 2 at the moment of ejection from the barrel.

[0031] Since the coded laser designator does not require precise muzzle attachment like traditional velocity measurement and airburst time writing coils, a single coded laser designator fixed to the outside of gun 4 can be used to program all shells fired from multiple rotary cannons. This solves the problem in existing technologies where high-rate-of-fire rotary cannons (such as the Type 730, Type 1130 close-in weapon systems, and Type 625 self-propelled anti-aircraft guns) cannot use intelligent programmable proximity-bomb shells. It also allows these high-speed rotary cannons, which previously could only use armor-piercing shells for direct interception, to possess a so-called "dual-hit system" function of "direct hit plus proximity-bomb fragmentation hit." This is highly advantageous for anti-aircraft guns to improve the hit rate against shells without penetrating warheads or armor-piercing projectiles, missiles (especially anti-radiation missiles coming directly at anti-aircraft guns), and small and medium-sized UAVs. This coded laser designator should ideally use a low-power laser, such as one below 0.5 watts. Its laser signal only needs to ensure that it can penetrate the propellant smoke at the muzzle and reliably illuminate the bottom of the just-fired shell 2 within a small cone angle. The lower the power, the easier it is for the laser beam's energy to be blocked by muzzle smoke and dissipated into the air earlier, making the launch code of shell 2 less likely to be detected by enemy reconnaissance methods such as drones. When the power is low enough to ensure that the laser penetrates the propellant smoke and rain mist and is received by shell 2 (at which point the launch power should be manually or automatically adjustable according to the current battlefield environment), the enemy will not be able to obtain this laser code signal, thus eliminating the possibility of the enemy activating the laser warning system or prematurely activating the active defense system (such as smoke launchers).

[0032] It should be emphasized that the description of the laser receiver 6 being installed at the bottom of the projectile 2 is for ease of understanding and simplification of the accompanying drawings and technical principles. A practically feasible solution also includes installing the laser receiver 6 on the tail fin of the rocket facing the launch platform. Regardless of the installation method, the laser receiver 6 always faces the launch platform and away from the enemy target 1. Therefore, there is no possibility of laser suppression or interference from enemy active defense systems such as Rheinmetall's "MUSS" and Israel's "IRON FIRST." Consequently, there is no need to employ anti-jamming technologies such as pseudo-random laser coding and gate gating. Therefore, the requirements for the performance, power, size, and cost of the fire control system and proximity fuse can be significantly reduced.

[0033] The aforementioned coded laser illumination system 3 also includes at least one coded laser designator capable of overcoming the bending of the trajectory due to factors such as gravity and wind, and ensuring that the turret or gun barrel can still point at target 1 when obtaining trajectory lead during elevation or horizontal rotation. This laser designator can ensure that the emitted coded laser illumination can always illuminate target 1 aimed by the artillery system 4 by increasing the laser divergence angle or mounting it on a rotatable platform. When it meets the needs of actual combat (such as applying this system to weapons with short range and low rate of fire such as grenade launchers, rocket launchers, and recoilless rifles), it can also be combined with the laser designator mentioned above for illuminating the bottom of the shell before and after leaving the barrel to transmit identification codes, sharing a single set of equipment.

[0034] The end-control proximity fuse setting and detonation system of this patent also includes a laser receiver 6 installed at the bottom of the projectile 2, and an electronic proximity fuse connected to the laser receiver 6. The laser receiver 6 includes a lens that transmits laser light, and a photoelectric conversion element covered by the lens—such as a photodiode or a more sensitive phototransistor—used to convert the coded laser light illuminating the laser receiver 6 into a pulsed electrical signal. To prevent interference from external natural light and battlefield illumination light on the photoelectric conversion element, one or more bandpass filter films should be pasted, coated, or plated (including vacuum ion sputtering) on ​​the lens of the laser receiver 6. This effectively shields other light of wavelengths not belonging to the coded laser, reducing the workload of the back-end filtering and decoding circuitry. This lens should preferably be made of materials capable of withstanding high temperatures and pressures, such as transparent aluminum with a transmittance exceeding 80% from infrared, visible light to ultraviolet light. Considering that after launch, the projectile 2 will deviate from its external trajectory due to internal ballistic factors at an angle of attack, and that the external trajectory curve of the projectile 2 is not a straight line, the laser receiving window of the laser receiver 6 cannot be perpendicular to the coded laser irradiator after launch. Therefore, the laser receiving window of the laser receiver 6 should preferably adopt a conical focusing channel structure that is wider at the outer edge and narrower at the inner edge to increase the maximum deviation angle threshold for the laser receiver 6 to receive the coded laser irradiation system 3. The appropriate cone angle value for this focusing channel is easy to calculate and will not be elaborated upon in this patent.

[0035] It should be emphasized that in this patent Figure 1 and Figure 2 In this diagram, the laser receiver 6 is positioned at the very center of the bottom of the projectile 2 for ease of explanation and identification. In actual applications, it can also be positioned at other locations on the bottom of the projectile 2 to avoid the exhaust port and other necessary structures at the bottom of the projectile.

[0036] The electronic proximity fuse includes a power supply module, a filtering and amplification circuit module, a shaping and decoding circuit module, a signal processing, storage, and calculation module, a detonation module, and an electric detonator (including fuse). Delayed self-detonation fuses and piezoelectric ceramic impact fuses can also be added as needed. Its function is that after the projectile 2 leaves the barrel, the laser receiver 6 receives the first laser beam coded with the projectile 2's unique identification code projected by the coded laser irradiation system 3, converts it into an electrical pulse signal, and transmits it to the electronic fuse. When using a post-exit programming scheme, the power supply of the electronic fuse can preferably be a chemical battery. Before the projectile leaves the barrel, it is activated and stabilized by a large acceleration overload and centrifugal force, ensuring a stable power supply to the electronic fuse upon exiting the barrel and simultaneously initiating the electronic fuse's initialization settings. At this time, the filtering and amplification circuit module filters and amplifies the electrical pulse signal transmitted by the laser receiver 6. The shaping and decoding circuit module performs secondary filtering on the analog signals transmitted by the amplification and filtering / amplification circuit modules, converts them into digital signals, and transmits them to the signal processing, storage, and calculation module. The signal processing and storage calculation module stores the first obtained digital identification code in the microcontroller or DSP and, after a certain period of time, commands the detonation module and electric detonator to open the fuse safety of the shell. It is important to emphasize that the stored identification code should be unique in a single shot or in a battle (for example, using the precise system clock data of the fire control system at the moment of the electric ignition or electronic fuse programming of shell 2 as the random value selected by the system; if necessary, the launch platform number can be added for encryption calculation before encoding). This stored signal is thus bound to shell 2, becoming the randomly acquired identification code of shell 2. Because the electronic fuse of the second shell does not require any high-impact, high-overload precision timing chip or rotation counting sensor, as well as a high-speed muzzle programming sensor (induction coil) and corresponding high-speed data processing and storage chip, and does not require high-power electromagnetic interference shielding protection for the electronic fuse circuit, the complexity of the fuse circuit, the requirements for analog circuit filtering performance, anti-interference capability, and computing chip speed are all greatly reduced. Therefore, the cost and reliability of the shell can be greatly improved, and the explosive charge of the shell can be increased by simplifying the size of the electronic fuse.

[0037] During the flight of projectile 2, the laser receiver 6 at its base may continuously receive coded laser signals. These signals may be the identification code to be written for subsequent projectiles, or the detonation code signal of previously fired projectiles. The laser receiver 6 will ultimately transmit them to the signal processing, storage, and computing module, which will then calculate and compare whether the identification code of projectile 2 matches.

[0038] When the shell 2 finally approaches the target 1 and reaches the detonation distance threshold, the fire control radar integrated in the search and fire control system 5 of the artillery 4, or the electro-optical detection system targeting the target 1, or the shell trajectory prediction calculation determines this time point. It then transmits the corresponding detonation code pulse laser to the pre-aimed coded laser illuminator 3, which is already aimed at the target 1, and to the target 1 and shells near the target 1, via a data link. This causes the shell 2, having received the correct detonation code, to detonate in the air. At this point, as long as the previously randomly generated identification code of the shell 2, which serves as the key, is not intercepted by the enemy, even if the enemy receives the detonation codes of other shells, they cannot reverse-engineer the detonation code of the shell 2 to interfere with its precise airburst operation. Since the light signal, which travels at the speed of light, can propagate at its maximum effective range of 10km for most direct-fire and medium-to-large caliber anti-aircraft guns (such as 76mm naval guns) or machine guns, does not require consideration of signal transmission time errors or can be compensated for by simple calculations within its maximum effective range of 10km, and the computational delay data of the fire control system and electronic fuse are stable, measurable, and pre-compensated in the computational program, firing the laser-detonated shell 2 at this time will not cause additional ranging and positioning errors between shell 2 and target 1. This ensures the maximum possible positioning accuracy of shell 2 upon near-detonation. At this point, through the data link networking and calculation of the fire control system, when target 1 is far enough away (for example, target 1 is several kilometers away from the artillery position, while the distance between artillery pieces 4 is only tens of meters), the trajectories of the distributed shells 2 that are aimed at the same target 1 can be approximated as parallel flight. The angle difference between the tails of the shells 2 and the artillery position is very small. Therefore, a single-coded laser illuminator with variable laser projection direction can even simultaneously irradiate and control multiple shells 2 launched from different artillery platforms to achieve proximity-to-air detonation when a fixed focal length is reasonably selected or a simple adjustment system is used to ensure that the laser divergence angle makes the laser field a cone with a certain reasonable cone. This can significantly reduce the cost of precise control of the artillery cluster, or enable the use of another system to control the proximity-to-air detonation of all artillery pieces 4 when one radar fire control system is destroyed by enemy anti-radiation missiles or other means. At this point, the laser illuminator can even employ a fixed focal length or a simple multi-point focusing optical system. This avoids the technical and cost issues inherent in laser beam-riding guidance, where the laser must continuously and precisely adjust its focal length based on the real-time position between the missile and the laser to ensure a constant laser spot area. Therefore, this system can achieve extremely low cost by adding only one or two low-cost shell identification coding laser illuminators to each existing non-intelligent anti-aircraft gun group, such as older stockpiled Type 74 37mm anti-aircraft guns or Type 99 twin 35mm towed anti-aircraft guns, and then adding a fire control system and one or more detonation coding laser illuminators to the entire anti-aircraft gun group.This allows for highly efficient air defense, equivalent to or even exceeding the capabilities envisioned by the German Rheinmetall Oerlikon Skyne distributed intelligent air defense system. This system comprises multiple 35mm programmable anti-aircraft guns, each controlled by a single radar and fire control system, forming what Rheinmetall calls the "Skynex" air defense network. This enables the rapid modernization of previously outdated artillery pieces at minimal cost. With this improvement, each artillery piece no longer needs its own high-performance fire control system and high-speed, high-precision muzzle traverse system. Precise proximity-based kills can be achieved simply by one or more shells approaching the target at any given moment within the barrage fired by the artillery cluster, instead of relying on increasing the quantity of ammunition to gamble on a low-probability direct hit, as was the case in the past.

[0039] It should be added that when the radar controlling the artillery 4 is an advanced radar such as a millimeter-wave radar that can simultaneously detect target 1 and shell 2 (such as the millimeter-wave radar of the Type 1130 close-in weapon system), the relative distance between shell 2 and target 1 can be measured and calculated by the radar and fire control system.

[0040] When the Artillery 4 system lacks an advanced radar system capable of tracking projectiles due to cost constraints (such as for tanks, infantry fighting vehicles, and the lowest-spec version of the 625mm self-propelled anti-aircraft gun) or the need for radar concealment, but possesses an electro-optical detector, the existing electro-optical imaging tracking system, while achieving a target tracking accuracy of approximately 0.1 to 0.5 milliradians (mRA), significantly higher than the minimum 0.5 mRA of ordinary centimeter-wave radar, is limited by CCD sensor technology (and similarly, CMOS sensors) and video processing hardware and software technology. This limits its ability to extract and track high-speed targets with weak signals, making it difficult to accurately track each projectile and determine the projectile's miss distance. For example, even disregarding cost, significantly increasing the number of pixels (i.e., increasing video resolution) of a CCD sensor can improve the chances of capturing images of small projectiles, but it also increases noise. Furthermore, increasing the number of pixels reduces the frame rate (the number of images output per second). In other words, the three key performance parameters for improving the success rate of projectile signal capture—"CCD pixel count, signal-to-noise ratio, and frame rate"—are contradictory and cancel each other out. To address the shortcomings of existing photoelectric imaging technology, a tracer tube can be added to the tail of the projectile 2. Alternatively, tracer tubes of different colors or high-brightness LEDs of different colors such as COB can be installed intermittently and cyclically between projectiles in a continuous ammunition belt to highlight and distinguish the images captured by each projectile 2. When using high-brightness LEDs to illuminate the image of the projectile 2 in the photoelectric detector, since most direct-fire projectiles will not have a flight time of more than 10 seconds within their effective range (taking a 35mm AHEAD projectile as an example, with a muzzle velocity of 1050m / s, it reaches its maximum range of 3000 meters approximately 3.98 seconds after leaving the barrel, meaning that the tracer only needs to last for a maximum of 4 seconds to meet the high-contrast tracking requirements of the photoelectric imaging tracking system for the AHEAD projectile throughout its flight), the power supply for a few seconds will not put much pressure on the power supply inside the projectile 2. Moreover, the LEDs can be lit up after a delay of a fraction of a second to one second after the projectile 2 is fired, or even later (again, taking a 35mm AHEAD projectile with a muzzle velocity of 1050m / s as an example, considering flight deceleration, its flight distance in 1.05 seconds is exactly 1000 meters, and at close range, the photoelectric detection system is relatively less likely to lose the projectile image) to prevent directly exposing the position of the artillery 4 and reduce the pressure on the power supply. We can further improve the contrast of each shell 2 in the photoelectric detector with the background image (generally the sky and clouds for anti-aircraft guns) and adjacent shells by combining multi-color tracer tubes or multi-color LEDs with polarizing lenses (for example, the tracer tubes or LEDs installed on the shell 2 in the ammunition belt or automatic feeder are arranged in a sequence such as "red, green, yellow, polarized red, polarized green, polarized yellow").If further improvements are needed in optical detection contrast and coding tolerance between each shell, a high-power LED tracer array with variable or multi-color properties can be installed at the bottom of the two shells. This allows for precise digital coding image recognition of high-density shells by setting multiple colors, or even periodically changing colors, of the tracer array at the bottom of the same shell. Since this method improves image contrast by changing the color of the tracer rather than its brightness, the image processing system can easily enhance the contrast between the shell and the background. This is because, from the perspective of image sensor technology and processing technology, noise generated in image sensors is mainly divided into two categories: brightness noise and color noise. Brightness noise, i.e., white highlights and black shadows, does not contain color information, and its impact can be completely resolved by the colored tracer of the shell. Color noise in image sensors is mostly randomly distributed and is often "thermal noise" caused by sensor heating, which can be mitigated by enhancing the heat dissipation of the image sensor. Furthermore, color noise that appears randomly in each frame is unlikely to exist continuously and stably in multiple consecutive images, making it easier to eliminate with algorithms such as frame-to-frame comparison. As for other random single-pixel color noise caused by signal amplification, it is easier to filter out by existing mature algorithms. Therefore, when the contrast between different projectiles 2, and the contrast between projectile 2 and the background image, are high enough, the probability of projectile-free imaging frames appearing in the image processing system will be greatly reduced. Moreover, by brightening the projectile tracer and using multi-color tracer contrast to achieve projectile photoelectric tracking, and using infrared tracking for the target, the problem of existing technologies being unable to track projectiles in low ambient light and at night can be solved. This enables anti-aircraft guns and artillery with photoelectric detector-based fire control to have the ability to conduct precise airburst close-range bombardment operations at night. This technical solution can largely solve the problem in existing technologies where photoelectric detection technology and detection systems cannot accurately measure the miss distance of projectile 2 (i.e., the distance between the missed projectile and the target) due to the large number of projectile-free frames in the captured video, thus making it difficult to achieve fire control closed-loop correction. At this point, although most optoelectronic detection systems are equipped with laser rangefinders, the current tracking and pointing accuracy and sensitivity of optoelectronic detection systems can generally only ensure that the rangefinder laser can lock onto target 1, but it is difficult to aim at each shell 2. At the same time, the laser rangefinder should not be continuously and frequently turned on to expose the specific location of the fire control system (some studies suggest that the sampling frequency of the laser rangefinder should be between 3.125Hz and 5Hz when considering all factors on the battlefield) or to trigger the laser illumination alarm of the target.Therefore, after solving the problem of no imaging frame for shell 2, the electro-optical detection fire control system can use image processing algorithms such as binocular cameras or camera arrays (for example, for close-range firing platforms such as rocket launchers and recoilless rifles, a single-camera ranging algorithm like YOLO can be used; for medium- and long-range firing platforms, deep learning algorithms, YOLO, RANSAC, DFDCNN, or Census, etc., binocular ranging algorithms, i.e., dual-camera ranging algorithms, can be used) to measure the distance and relative distance between target 1 and shell 2. This technology is relatively mature due to the development and popularization of autonomous driving technology and IRST (Infrared Search and Track System) technology in civilian vehicles, and will not be elaborated on in this article. At the same time, the "dual-station positioning ranging method" and "single-station positioning ranging method" in passive infrared ranging technology can also be considered for ranging shell 2. Both are well-known technologies in the military industry and will not be described in detail in this article. At this time, since the television or infrared photoelectric detector of the electro-optical system needs to track and aim at target 1 in real time, the coded laser illuminator used to emit the detonation code can be integrated into the follow-up platform of the electro-optical system detection system to reduce system cost. Of course, tracer rounds and ordinary rounds can also be arranged alternately on the ammunition belt. Since the firing rate and projectile velocity of the rapid-fire gun can be predicted, the distance between several ordinary rounds between two tracer rounds can also be calculated by the fire control system. As long as the position of the tracer round can be accurately located, the position of the ordinary rounds in between can also be calculated.

[0041] When the artillery system 4 cannot be equipped with radar and electro-optical detection systems due to cost, size, or weight constraints (such as on man-portable grenade launchers, recoilless rifles, rocket launchers, etc.), but can still perform simple range finding or manual distance estimation for target 1, it can also measure the initial velocity of the fired projectile 2 (or the fire control system can estimate the initial velocity using pre-set propellant temperature) and have the coded laser illumination system 3 send an identification code to projectile 2. Then, based on the initial velocity, the fire control system calculates the distance to target 1 and the deceleration curve of projectile 2 caused by range and elevation angle (for simplified fire control systems used in close-range weapons such as rifle grenade launchers, this calculation result can be quickly read from a data table obtained through repeated test firings rather than calculated in real time). After calculating the flight time and determining that the distance between the warhead and target 1 has reached a set threshold, the coded laser illumination system 3 is controlled to fire a detonation code signal at target 1 and projectile 2 near target 1 to achieve proximity-to-air detonation. This control mode is very suitable for low-cost and lightweight man-portable, lightweight UAV-borne, or lightweight vehicle-mounted weapons. In fact, ATK's Bushmaster airburst grenade and the US military's XM-29 grenade launcher even employ open-loop control logic for airburst position, where the ammunition is programmed directly on the loading mechanism without measuring the projectile's velocity. Therefore, the cases of the "US Future Individual Combat Weapon System" and the Bushmaster airburst grenade, which pre-set airburst parameters without velocity measurement, demonstrate that for low-speed or stationary targets (such as enemy machine gun emplacements or low-speed vehicles), the airburst position accuracy of this patented method, which uses muzzle velocity measurement followed by proximity parameter calculation, is perfectly adequate and significantly higher than that of the Bushmaster airburst grenade. In this case, the velocity measurement component for projectile 2 can be selected from muzzle induction coil velocity measurement, eddy current velocity measurement, pulse laser velocity measurement, laser phase velocity measurement, or direct laser grating velocity measurement, all of which are mature and well-known technologies in both civilian and military fields. This proximity-based control principle suffers from low accuracy in fire control system ballistic simulation and various disturbances in the external trajectory, making it impossible to accurately determine the projectile's miss distance. When intercepting high-speed and highly maneuverable targets, it's advisable to continuously detonate several projectiles predicted to be close to target 1, creating a fragmentation zone instead of detonating individual projectiles 2 each time. This is similar to using mine-clearing explosives to detonate randomly distributed mines, thus improving hit probability. This approach is particularly suitable for upgrading low-cost combat robot platforms, allowing low-cost platforms like "robot dogs" to cover enemy forces with proximity-based attacks using rockets, grenades, or recoilless rifled shells, eliminating the need for precise target aiming.

[0042] Besides the above-mentioned solutions, when cost is a constraint and the system cannot perform actual measurements but can only simulate and estimate the trajectory and specific spatial location of the projectile, there is another method to achieve reliable airburst. For example... Figure 2As shown, by rationally designing the taper of the light-transmitting aperture of the laser receiver 6 or increasing the number of laser receivers 6, and arranging the coded laser irradiation system 3 at a large distance away from the "line connecting the artillery, shells, and target," it is possible to ensure that the laser divergence angle of the emitted laser (at this time, it is advisable to design a precision continuous zoom system similar to that of a laser beam-riding guided laser irradiator) makes the target 1 appear as if it were locked by a guiding laser in a laser beam-riding guided mode. The target 1 will be continuously enveloped in a light cone bottom section of a fixed radius (it should be emphasized that at this time, the focal length is dynamically adjusted, and it is advisable to measure the distance to the target 1, but the difficulty of measuring the distance to the target 1 is much less than that of measuring the distance to a large number of shells 2), and ensure that the radius of the light cone bottom section is less than or close to the kill radius or kill area of ​​the shell 2. By rapidly and continuously looping (i.e., high repetition frequency and short duration) a series of detonation codes for shells 2 within this light cone, shells 2 flying towards target 1 but not close enough will not receive the detonation codes because they are still outside the light cone. However, when one shell 2 in the series is close enough to target 1, it will be covered by the laser cone of detonation codes, thus being activated within the kill radius by the looping detonation codes and achieving proximity detonation. The key to implementing this scheme is that the detonation code for each shell 2 should be short enough to loop a set of detonation codes within a sufficiently short time, and the electronic fuse decoding speed of the shell 2 should also be fast enough to prevent the shell 2 from missing the target during multiple detonation code loops. For an artillery array consisting of a small number of artillery pieces 4, this is not difficult to solve with existing technology. However, for a gun group consisting of a large number of artillery pieces distributed at a wide distance, rotating the detonation codes of different shells would significantly affect the airburst positioning accuracy. Therefore, it is also possible to use a unified time code for different artillery pieces or other launch platforms.

[0043] Taking a simple, unencrypted encoding scheme as an example, the identification codes of the shells 2 fired by each cannon 4 at the same time are "N+Xy", where N can be the time difference between the time of firing shell 2 and the "synchronization time" (or time of time synchronization) of each cannon 4, and Xy is the compensation time code (denoted as X) required due to the flight time difference when shells 2 fired by different cannons 4 (the cannon identification code is set as y in this article) approach the future predicted position (also known as the "target domain") of target 1 (hereinafter referred to as target 1 for simplicity) after firing, because the placement positions of the shells 2 are different from the target 2, and the trajectory arc lengths are different. Further examples include... Figure 2As shown, there are two cannons 4 in the artillery group, distributed at a relatively large distance. At a certain moment, assuming the search and fire control system 5 calculates that the flight time of the left cannon shell 2 towards the future target 1's intersection area is 2.746 seconds (for ease of reading and understanding, this patent assumes the timing and calculation accuracy of the fire control system is simplified to 1ms), and it arrives at target 1 0.634 seconds faster than the right cannon shell 2. Then, in the simplest case without considering encryption of the detonation code, an identification code N+2746 can be assigned to the cannon shell 2 fired by the left cannon 4 at the current moment, and an identification code N+2746 can also be assigned to the first cannon shell 2 fired by the right cannon 4 around 0.634 seconds (the time before and after this point considers system error, and its threshold is calculated separately). Furthermore, assuming the time difference between the cannon shell's firing time and the fire control system's previous clock reset time is 12.875 seconds, then N=12875. Therefore, when the laser illumination system 3 cyclically fires detonation code 15621 (i.e., 12875+2746) at target 1, both shells 2 on the left and right will be detonated at approximately the same target distance and at the same time. When the same laser illumination system 3 controls more artillery pieces 4, the specific Xy codes of more shells 2 can be deduced in the same way. Of course, as target 1 continuously changes its spatial position, the distance difference correction time Xy in N+Xy of the identification codes of different shells 2 needs to be continuously corrected and changed. The value N can also be periodically and synchronously reset to zero to reduce the number of digits in the detonation code and prevent the enemy from intercepting the identification codes of shells 2 and interfering with them. This solution avoids adding expensive and easily detected anti-radiation missile-equipped high-precision fire control radars and sophisticated electro-optical image tracking systems to existing stockpiled anti-aircraft guns. It only requires adding a low-power laser illumination system 3 to input the identification code of the shell 2, a simple rangefinding and electro-optical tracking system to track the target 1, and a wired or wireless real-time shell identification code encoding data transmission system for the corresponding "cloud" fire control system. This enables the upgrade of the artillery's programmable airburst function, greatly reducing the fire control technology requirements and modification costs of the artillery 4 firing platform to achieve accurate and intelligent airburst proximity bombardment. It can retrofit old stockpiled anti-aircraft guns and infantry fighting vehicles at the lowest cost, and is especially suitable as a supplement and upgrade to the "distributed (anti-aircraft gun) weapon system" and "distributed fire control system" projects researched by our army around 2005.

[0044] This is easy to understand because the principle of proximity-to-air detonation control for shell 2 is as simple as an infrared remote control for pointing at household appliances. Therefore, the amount of data transmitted by the coded laser illuminator to a single shell 2 can be very low, but we can still use high code rate and high data transmission rate laser modulation coding to reduce laser illumination time. In current civilian technology, the optical wireless communication technology under the IEEE 802.11bb standard published by the Institute of Electrical and Electronics Engineers (IEEE) has a theoretical bandwidth of 224 GB / s, while the identification code data for a single shell only needs to be in KB. That is, without considering the signal processing speed of each shell's electronic fuse and environmental interference such as occasional explosion smoke fragments blocking laser signal transmission and data packet loss, theoretically, within one second, the same laser illumination system 3 (with a sufficiently large light cone divergence angle) can simultaneously control the precise airburst of millions of shells. Conversely, theoretically, the optical signal communication time required for each shell 2 can be as low as one ten-millionth of a second, lower than the alarm threshold of noise signal filtering circuits in most laser illumination alarm devices. This means that in most implementations, the system does not need to continuously and precisely illuminate the target 1 with a laser, as is the case with semi-active laser guidance (such as the UK's self-proclaimed advanced "Starlight" air defense / anti-tank missile) and laser cross-beam guidance. Instead, it only needs to fire a very short laser beam to illuminate and detonate the projectile 2 when it is determined that the projectile 2 is about to or has already reached the designated position. Therefore, even if the target 1 is equipped with a laser illumination alarm, it will be ineffective or destroyed by the proximity explosion of the projectile 2 at the moment the alarm is triggered, leaving no time for maneuvering evasion or electro-optical countermeasures. At the same time, since the one-way response principle of the projectile 2 is similar to that of an infrared remote control lamp holder or remote control bulb, the internal electronic airburst fuse is only responsible for decoding the encoded signal and does not undertake high-precision timing, counting of rotations, or active laser ranging calculations based on diffuse reflection laser image analysis. Therefore, its internal electronic fuse has very low requirements for power supply and microcontroller chip computing power, which greatly reduces the cost of the electronic fuse and significantly improves its reliability and response speed. This means that the control logic of the existing programmable proximity explosives has been changed from the "edge computing" (for shell 2) mode, where the shell 2 has its own high-speed and accurate computing power and needs to accurately time the launch but cannot perceive the specific location of the target 1, to the "cloud computing" (for shell 2) mode, where the search and fire control system 5, which has stronger computing power and is less sensitive to cost, undertakes all the calculations. It also eliminates the accuracy problems of the existing technology, which requires the setting of multiple muzzle velocity measuring coils and programming coils, and the impact of adding coils on the accuracy of the cannon 4, which causes the center of gravity of the cannon 4 to move forward towards the muzzle.More importantly, the AHEAD round, 3P round, the PLA's existing 35mm airburst round, and the Bushmaster airburst round have already been programmed with airburst parameters in the feeding mechanism or when they leave the barrel and pass through the programming coil. The control of the proximity position of the actual target 1 is essentially an open-loop control state. Its airburst positioning accuracy depends heavily on the fire control system's prediction and estimation of the target 1's flight time of several seconds to tens of seconds in the future. If the target 1 is a high-speed aircraft capable of complex trajectory changes (such as a manned ultra-low-altitude fighter jet and a supersonic anti-ship ballistic missile with terminal continuous trajectory changes), the interception efficiency of the anti-aircraft gun will be greatly reduced. Because of its open-loop control precision issues, existing proximity shells must be detonated at a considerable distance from the target to create a fragmentation barrage with the largest possible kill radius (for example, for the AHEAD shell, this is an inverted cone barrage with a depth of at least 10 meters and a diameter of at least 8 meters) to improve the interception rate. However, the "far-netting" and "wide-netting" open-loop control logic of detonating as far away from the target as possible to create a barrage with the largest possible interception area inevitably reduces the number, density, and kinetic energy of fragments and projectiles that can actually hit the target. This increases the probability of hitting armored heavy attack helicopters, heavy fighters, and attack aircraft and bombers with ultra-low-altitude penetration, but greatly reduces the single-shot kill capability. Conversely, the system of this patent possesses closed-loop control capabilities. It can cover the airspace where target 1 is located or about to arrive as much as possible by firing a large number of low-cost shells 2. For shells 2 that are too far from target 1 due to low first-shot hit probability or environmental interference, the search and fire control system 5 can directly abandon tracking. This significantly reduces the computational speed and target tracking capability requirements of the search and fire control system 5. All shells 2 that approach target 1 will enter the light cone covering target 1 and be reliably detonated by the coded laser, thus avoiding the "near miss" phenomenon. Moreover, by reasonably adjusting the cross-sectional area of ​​the coded laser light cone, we can use closed-loop control to ensure that shells 2 only explode when they are sufficiently close to target 1. This greatly increases the density, quantity, and impact kinetic energy of fragments hitting target 1. At the same time, as the search and fire control system 5 of our artillery continues to improve the search accuracy and movement path prediction accuracy of enemy target 1 through software and hardware upgrades in future improvements, the airburst accuracy of this closed-loop control will also be improved simultaneously without any upgrades to stockpiled ammunition.

[0045] Alternatively, we can leverage the advantage of this patented system—that it avoids significant "near-miss" at long ranges due to calculation errors in the fire control system's prediction of future target distance and external ballistic errors—to further and substantially increase the effective range of airburst rounds. For example, ballistic calculations using the 35mm anti-aircraft gun tracer rounds used by our military (detailed calculations can be found in Dr. He Zhencai's doctoral dissertation, "Research on Precise Control Technology of Fuze Airburst Point," at 4000 meters) show an error of less than one ten-thousandth in the trajectory arc length and oblique firing range. However, once outside the effective range, the error, even within the oblique firing range of 3670 meters to 4116 meters, increases from 2.7 × 10⁻⁶. -5 Rapidly increased to 9.7×10 -5 This means that the error increased by a factor of 3.6 within a 446-meter oblique firing range difference. Therefore, it's easy to understand that beyond an effective range of 4000 meters, the fire control system can hardly simulate the trajectory of the PLA's 35mm anti-aircraft gun tracer rounds using a straight trajectory. This means that the same caliber programmable airburst rounds from Switzerland's Oerlikon, Sweden's Bofors, the US's Northrop Grumman, and the PLA's existing programmable airburst rounds that perform muzzle velocity measurement and programming at launch can only have the same effective range. However, this patented system, which does not rely entirely on muzzle velocity measurement and trajectory calculation, can still significantly increase the effective range limit even when used to attack small, long-range flying objects that traditional programmable munitions struggle to handle.

[0046] To illustrate further, the existing AHEAD airburst warhead contains almost no explosive charge. Its control method involves the internal airburst fuse's timer counting down to zero, then opening (using a trace amount of explosive, approximately 1 gram), which detonates the warhead's wind cap or fairing, thus ejecting the internal tungsten alloy sub-projectiles. Therefore, the terminal velocity and kinetic energy of the tungsten alloy sub-projectiles are provided by the propellant. This results in the AHEAD warhead's kinetic energy decreasing with distance, meaning its destructive power decreases. The closer to its claimed maximum range of 4km, the greater the warhead's deceleration, leading to a significant reduction in the volume of its coverage cone (meaning the coverage cone is far smaller than its nominal maximum diameter of 8m and maximum length of 10m), as well as the sub-projectile's kinetic energy and penetration effect. Furthermore, assuming the AHEAD warhead can achieve an airburst at close to medium range with 152 tungsten alloy sub-projectiles evenly distributed within a maximum cone diameter of 8m (50.24 square meters), then there would only be one sub-projectile per 0.331 square meter cone cross-section. Not to mention that the AHEAD bullet's internal warhead is actually arranged in several rings within the kill cone rather than being evenly distributed. This makes it suitable for attacking large targets such as armed helicopters, but its airburst hit efficiency against small targets such as small commercial drones and micro military reconnaissance drones is likely insufficient.

[0047] To further illustrate, the DJI Mavic Air drone, widely used for reconnaissance, has unfolded dimensions of 168 mm × 184 mm × 64 mm. Its maximum projected area is 0.031 square meters, and its minimum projected area is 0.012 square meters. This means that even under the most ideal theoretical conditions, where the 152 tungsten alloy bullets of the AHEAD round are evenly distributed across the base of an 8-meter diameter cone, it would likely require firing 10 to 30 or more rounds to completely cover the kill cone before a single bullet would have a high probability of hitting the DJI drone. Furthermore, the bullets of the AHEAD round are not actually evenly distributed within the kill cone. Conversely, the airburst projectile of this patent utilizes the kinetic energy and kill radius of the numerous fragments generated by the explosion of the internal explosive charge (for example, a domestically produced 35mm anti-aircraft gun shell of the same caliber as the AHEAD shell can maintain a stable kill radius of 8m × 17m at any distance without reduction, meaning it can have more than twice the kill radius and a much higher fragment spatial distribution density at long range) without linearly decreasing with the deceleration of the projectile. Furthermore, in addition to fragments, the detonation products and shock wave of the explosive charge itself also have a damaging effect on the target. This allows the artillery system using this patent to overcome the inherent problem of increased trajectory curvature beyond the traditional range limit by upgrading the fire control system, ballistic computer and its algorithms, and firing more shells 2. Even beyond the maximum effective range of traditional anti-aircraft guns and machine guns, it can still detect and control several individual shells 2 that are sufficiently close to the target 1 for precise airburst damage from a large number of fired shells 2, thereby extending the effective range of traditional artillery. For fire control systems, this simply means that the corresponding algorithm for ultra-long-range firing can expand the target area and increase the amount of ammunition delivered within a reasonable range. However, this is impossible for impact-detonating shells and AHEAD shells that control airburst accuracy using non-intelligent "edge computing" logic. This is because whether an AHEAD shell can hit the target is determined the moment its muzzle programming is completed. Its fire control algorithm requires the smallest possible target area. Once the future flight trajectory of target 1 is estimated to be incorrect, there is no possibility of hitting the target. However, the system in this patent can still compensate for this by increasing the target area and the number of firepower projected.

[0048] The ease of understanding, longer effective range, larger kill radius, and lack of limitations imposed by parameters programmed during muzzle firing make it highly valuable for intercepting saturation attacks from enemy drones, anti-radiation missiles, cruise missiles, and glide bombs. It is particularly advantageous in intercepting high-G, high-maneuverability unmanned aerial vehicles (UAVs) with basic AI that can continuously maneuver and change course (when they detect being locked onto by radar), which are bound to emerge in the future. (Human pilots are generally considered to be able to withstand a safe G-force of 6.5G for a short period, with a maximum instantaneous acceleration of around 9G, and cannot maintain this maneuvering G-force for extended periods, while UAVs do not have these limitations.)

[0049] Furthermore, existing muzzle-sensor-programmed airburst projectile technology requires the detonation time or detonation speed to be set in real-time to the electronic fuze within tens of microseconds before and after the projectile leaves the muzzle using an inductive setting method. However, programmable airburst projectiles are constrained by various physical factors, such as the size of the fuze programming coil and the internal signal induction coil of the projectile, making it difficult to achieve inductive programming for projectiles with calibers of 25mm and below (ATK claims to have conducted research on the 25mm Bushmaster airburst projectile, but even though the Bushmaster airburst projectile does not require muzzle velocity measurement, programmable airburst projectiles with calibers less than 30mm have never been actually deployed). Conversely, my country's current technology for manufacturing miniature lenses for pinhole cameras (with diameters as small as 0.4 mm, approximately the size of 2 to 3 human hairs) is already very mature. Furthermore, the lens of the laser receiver 6 in this patent only needs to transmit beams of light of varying intensities without needing to consider distortion of the optical path and image details. Therefore, a Fresnel lens, which is easy to mass-produce and has very low processing costs (requiring only rough machining such as chemical etching or cutting), can replace the convex lens, which requires precision grinding. This eliminates the size limitation of the projectile's minimum diameter of 30 mm. Thus, before the adoption of proximity explosives, the PLA's existing small-caliber anti-aircraft guns, such as the 625mm self-propelled anti-aircraft gun, can only use specific fire control algorithms based on "satisfactory index estimation and satisfactory control theory of tracking systems" to project a calculated number of proximity explosives or armor-piercing projectiles into a certain range of "target domain" to achieve the expected hit probability. This algorithm is effective against targets with sufficiently large projected areas (the magnified area of ​​the target domain) such as cruise missiles, attack helicopters, and low-altitude penetration fighters and bombers. However, for smaller targets like anti-ship missiles, anti-tank missiles, drones, and loitering munitions, especially those with constantly random or intelligent trajectory changes and "human-in-the-loop" control, it may require launching munitions one or more orders of magnitude more to achieve a direct hit. However, once reliable proximity explosives are used, only a small amount of precisely controlled proximity explosives needs to be deployed into the target domain to achieve reliable damage. Therefore, programmable airburst ammunition can be equipped, significantly improving the combat effectiveness of small- and medium-caliber anti-aircraft guns and enhancing their sustained combat capability with the same amount of ammunition. Similarly, this advantage is also beneficial for upgrading the Air Force's 23mm cannons.

[0050] It should be added that when a large number of artillery pieces 4 are simultaneously aiming at the same target 1, there may be instances within a short period of time where the laser receiver 6 of the same shell 2 receives detonation code lasers emitted by different coded laser illumination systems 3 from multiple different artillery pieces 4 targeting different shells. When a large number of pulsed laser signals overlap with the same laser receiver 6, it may cause the electronic fuse of the shell 2, which is composed of a simple filtering circuit, to fail to effectively filter and extract the required detonation signal. At this point, we can significantly reduce the duration of the detonation signal illumination for each shell by increasing the code rate, and by changing the re-emission interval of the detonation code signal for shells that need to be detonated immediately but failed to detonate due to code loss or other reasons and need to re-communicate, in order to reduce the possibility of signal overlap. Alternatively, we can directly set different optical pulse signal modulation frequencies in the fire control channels of different shells, or use significantly different minimum symbol intervals for optical pulse signals to reduce the filtering difficulty of the electronic fuse of the shell 2. Furthermore, we can improve the signal-to-noise ratio when a single shell 2 receives and analyzes the illumination signals from multiple coded laser illumination systems 3 by using tunable laser systems with different wavelengths of laser and corresponding bandpass filters in the laser illumination systems and corresponding shells of different shells. Another simple method is to attach a light-converting film to the lens of the laser illumination system of the shell 4 to quickly change the laser frequency emitted by each shell, and attach a corresponding light-converting film to the lens of the laser receiver 6 at the bottom of the corresponding ammunition. Due to the rapid development of the domestic photovoltaic industry, light-converting films capable of changing spectral frequencies are already in mass production. These kinds of technical means are the most basic and well-known technologies in the field of signal anti-interference technology, and will not be discussed in detail in this patent.

[0051] As another preferred solution for the practical application of this patent, if our military upgrades the artillery reconnaissance radar of traditional howitzer units, or enables the fire control system of each howitzer to connect with the data link of the accompanying air defense system, so that its detection accuracy against UAVs meets the threshold, then it is only necessary to add a laser illumination system 3 to the existing howitzer units to encode the shells 2 fired from the muzzle. Then, by adding a laser illumination system 3 to the artillery reconnaissance radar fire control system or the accompanying air defense system to illuminate the target 1, the howitzer can also fire dedicated large-caliber airburst shells when needed. Utilizing the significantly larger fragmentation area compared to small-caliber anti-aircraft gun airburst shells, it can intercept a large number of UAVs, cruise missiles, and ultra-low-altitude aircraft attacking artillery positions or passing by with high precision and efficiency at long range. Because the muzzle velocity of large-caliber howitzer shells is relatively lower than that of anti-aircraft gun shells, and the projectile volume is larger with a lower rate of fire, the technical difficulty for the search and fire control system 5 in measuring the distance between the projectile and the target and determining the moment of projectile-target intersection will be greatly reduced. If data fusion can be achieved between artillery reconnaissance radar and infrared photoelectric sensors of accompanying air defense systems such as the Type 625 self-propelled anti-aircraft gun, research papers such as Wang Shinian et al.'s "Design and Implementation of Anti-UAV System for Key Area Protection" show that the positioning accuracy of UAVs can be improved by more than three times. Furthermore, if howitzers can be equipped with "axially enhanced projectiles"—the specific principles and structure of which can be found in Zhang Hui et al.'s paper "Optimization Control and Anti-missile Effectiveness Analysis of Axially Enhanced Projectile Fragment Field"—the detection accuracy requirements of the fire control system at the moment of projectile-target intersection can be further reduced. If the fire control system algorithm of the howitzer is further upgraded and improved, enabling it to achieve near-simultaneous impact of multiple rounds from a single gun against ground targets by increasing or decreasing the propellant charge and altering the trajectory, a denser aerial fragmentation barrage can be formed in a rapid firing salvo, further enhancing the air defense effect of large-caliber howitzers. This would partially solve the problem of reconnaissance-strike drones, mortar shell-launching shuttles, and loitering munitions being the biggest counter-battery threats. It would also make tactics that rely on drones and loitering munitions to destroy large-caliber artillery and self-propelled artillery in large numbers ineffective against our artillery, especially self-propelled howitzers. Furthermore, this technological approach could potentially replace Israel's Iron Dome for intercepting rockets and low-velocity projectiles through continuous technological upgrades and iterations, and ultimately even intercept enemy counter-battery fire. It's easy to understand that the airburst accuracy of this large-caliber airburst projectile is primarily limited by the fire control system, rather than the timing or rotation accuracy of each projectile's time fuse. It can also network with mobile artillery reconnaissance radars or air defense radars deployed near howitzers, utilizing their radar, electro-optical sensors, and fire control system computing power to control the operation of the coded laser illumination system, achieving centralized control and distributed deployment to further reduce system costs.Its control principle may be more accurate and cheaper than the 155mm air defense proximity grenade (which the US military reportedly began researching in 2013 and began adapting and testing for the M109A6 self-propelled howitzer on September 2, 2020, and which is still under development) that is similar to a radio command guided air defense missile (the main difference between it and a radio command guided air defense missile is that the gun-launched missile of the HGWS system uses a GPS system for self-positioning, rather than installing a millimeter-wave radar inside the warhead to track the target), which can only deal with the subsonic BQM-157 target drone. It must be emphasized that the main reason why current technology limits the use of large-caliber howitzers for air defense is that, unless the warhead structure of the projectile is completely redesigned (i.e., the "axially reinforced projectile" mentioned earlier), the fragments produced by existing natural fragmentation or pre-fragmented high-explosive shells during airburst are far from uniformly distributed in space. They are not the "fragment kill radius of 60 meters," "covering more than a football field," or a "fragment cloud" described by some military media. Instead, a "fragment ring" is formed due to the presence of a fragmentation direction angle φ0, which is related to the projectile's real-time flight velocity, between the fragmentation direction and the ejection direction, resulting in a large number of gaps in the spatial distribution of fragments. More specifically, experimental tests have found that the static fragmentation angle Ω of a 127mm high-explosive shell is only about 65°, and the dynamic fragmentation angle Ω continues to decrease. At the same time, numerous studies have found that the fragmentation field density of high-explosive shells decreases significantly with increasing distance between the projectile and the target, and the lethality is also closely related to the mutual trajectories between the projectile and the target. Therefore, the kill zone and effective kill radius of a large-caliber howitzer during an airburst are drastically different for targets with varying frontal areas, relative trajectories, and relative velocities. In actual combat, the target area and kill zone of large-caliber howitzers intercepting targets of varying sizes, such as low-flying fighter jets and attack helicopters, glide bombs (like the US JDAM or "Dynamic JDAM"), land-based small-diameter munitions (GLSDB), small air-to-ground missiles (like "Hellfire" and "Maverick"), small drones and loitering munitions, or howitzer shells, will vary by several orders of magnitude. For example, Lan Tian of Shenyang University of Technology, in his master's thesis "Research on the Damage of Fragmentation Warheads to Aerial Targets," showed that a naturally fragmented 155mm high-explosive anti-tank round has a frontal area of ​​4m². 2 up to 20m 2 The kill space for reconnaissance balloon-level targets is approximately 4400 m² at an initial fragment velocity of 1400 m / s. 3However, it's clear that the kill zone of the same high-explosive fragmentation shell against a small drone would be reduced by several orders of magnitude. This means that a closer approach to the drone is required for a close-range airburst to inflict effective damage. This presents significant challenges and drastically increased costs for a range of technologies, including the high-speed signal parameter setting of the airburst fuse, the positioning accuracy of the projectile's own high-speed real-time 3D GPS data receiving module (a key technology of HGWS), the data link transmission of the target's real-time 3D positioning data (also a key technology of HGWS), and the radio proximity fuse detection capability. This is likely why the US military has been unable to commercialize the "Multi-Domain Artillery" (HGWS) system since 2013. However, as mentioned above, without being constrained by the performance and accuracy of the intelligent fuse of the ammunition itself, based on the target search, analysis and classification capabilities of the search and fire control system 5 of this patent, and relying on the high-speed computing capabilities of the search and fire control system 5 that are impossible to achieve with the intelligent fuse inside the warhead, the full closed-loop control of the airburst position of the ammunition can be realized. In addition, with the aforementioned "(fragment) axially enhanced projectile" and other technologies as supplements, the problem that the US military has been unable to solve to this day—the problem of intelligent airburst fuses for large-caliber high-explosive fragmentation grenades intelligently selecting airburst positions for different targets, as well as the corresponding system reliability, control accuracy and the resulting cost issues—can be effectively solved.

[0052] Therefore, in the future, large-caliber howitzer units may not need to adopt "hit-and-run" tactics when facing enemy ground-based air forces and loitering munitions without stealth capabilities. This would greatly improve the PLA's sustained firepower projection capability and allow tracked self-propelled artillery to intercept aerial targets while on the move. To further reduce costs, if the projectile 2 in this patent is designed and stored separately from the fuze and warhead, like the 155mm howitzer shell and installed before use, it could also consider referencing the US military's PGK (Precision Guidance Kit) precision guidance kit project for its stockpiled conventional 155mm howitzer shells. This would involve directly installing an electronic proximity fuse module on the top of the existing stockpiled howitzer shell warhead to replace the original fuse, and fixing a separate laser receiver 6 module at the bottom of the warhead. The split-type laser receiver module 6 can be a disc-shaped structure fixed to the bottom of a common grenade warhead by pasting, clamping, magnetic attraction, or a combination of these methods. Alternatively, it can be a sleeve-type structure inserted into the recess of the bottom or the bottom-row extended-range grenade and fixed therein. This split-type laser receiver module 6 should transmit detonation code data wirelessly to the electronic proximity fuse module installed on the top of the warhead. However, it is also possible to add a large capacitor or a high-frequency signal transmitting antenna based on self-excited oscillation (used to absorb and consume a small amount of signal current) to the fuse at the front of the warhead to replace the neutral wire and form a short-term temporary circuit. The metal shell of the warhead can be used as the live wire to transmit a brief AC signal or anti-interference digital signal between the fuse and the split-type laser receiver 6 at the bottom. The specific circuit principle can refer to the voltage testing principle of a test pen that uses a human body insulated from ground or an ungrounded antenna as a capacitor or load in known electronic technology, and the "single live wire touch switch," etc., which will not be elaborated in this patent. Since the shell 2 is generally used for airburst attacks in air defense missions and suppression of direct-fire targets within 5 kilometers of the ground, the slight deviation of the center of mass of the warhead caused by the split laser receiver 6 module has little impact on the close-range airburst accuracy caused by the change in the stability of the internal and external ballistics of the projectile, and can be compensated for by changing the firing data parameters in the firing table.

[0053] It should be added that this patent also has a special application embodiment. If in the future our military wants to develop long-range gun-launched missiles for fourth-generation tanks that are equivalent to or even superior to the XM943 STAFF fly-by-fly top-attack multi-purpose munition and the XM1111MRM dive-attack top-attack multi-purpose indirect-fire munition used by the US military on the Abrams X, capable of attacking enemy targets and fortifications beyond visual range from 5 kilometers to over ten kilometers, then the existing laser beam-riding guidance system and gun-launched missiles, which are derived from Russian technology and can only operate within visual range, will no longer be effective. In fact, the US military began researching the STAFF beyond-visual-range gun-launched missile after 1990, but the project was halted in 2000 and then restarted, yet it has yet to be finalized and deployed. The main reason is likely that it is difficult to install a large-capacity, high-power battery and a high-performance active search seeker with a wide field of view and long operating time within the size of a gun-launched missile. Data shows that it must rely on forward-deployed drones or reconnaissance helicopters (such as the Comanche stealth reconnaissance helicopter, which was discontinued by the US military four years after the STAFF project was halted) to continuously update the enemy's real-time location via a high-speed, high-precision IVIS (in-vehicle communication system; after the US military implemented the so-called Integrated Visual Augmentation System "IVAS") battlefield network data link for target reconnaissance, detection, relay guidance, and even terminal guidance for STAFF and XM111MRM gun-launched missiles. However, in actual combat, high-performance, high-cost gun reconnaissance and guidance drones and reconnaissance helicopters with high target detection and missile guidance accuracy may not be able to accompany and advance to provide reconnaissance and guidance for tanks throughout the entire battle. Conversely, if the cost and equipment of drones and reconnaissance helicopters are already acceptable enough to equip them with high-performance radar, electro-optical observation and missile guidance systems, and high-performance IVIS battlefield network data links, then why not let drones and reconnaissance helicopters carry cheaper, terminally guided miniature top-attack anti-tank missiles or miniature loitering munitions that can be launched closer to the target for direct attack, instead of having them advance to guide the more expensive and longer-flying "human-in-the-loop" gun-launched missiles launched from the tanks behind them? Therefore, not only are the ammunition for STAFF and MRM gun-launched missiles complex and expensive, but the entire combat support system is also very expensive and unreliable.

[0054] Conversely, our military only needs to integrate a low-power coded laser illumination system 3 and a simple, low-bandwidth data link system (requiring only target locking capabilities from the UAV, without the need for real-time transmission of multiple high-speed, low-latency video streams between the fire system and the UAV) into forward-deployed micro or small reconnaissance UAVs. This allows them to estimate the time it takes for our beyond-visual-range artillery-launched missiles to approach an enemy target several kilometers away using photoelectric sensors or ballistic calculations. Then, by illuminating the laser receiver 6 of the artillery-launched missile with the coded laser, they can activate the high-power active guidance seeker and booster engine, which only require a short time (e.g., a few seconds) to operate. This avoids the problems of the US military's long-range artillery-launched missiles requiring high-cost UAVs or reconnaissance helicopters for continuous guidance and advanced artillery-launched missiles requiring high-performance infrared focal plane array detectors, large-capacity batteries, and rocket boosters and trajectory maneuvers under full-range human-in-the-loop control. Even disregarding cost and reliability issues, the excessive fuel required for continuous trajectory maneuvers and the large volume of batteries for continuous active homing or long-term relay guidance significantly reduces the range and warhead power. If the amount of laser-coded data from the UAV is further increased, the laser identification code data received by the gun-launched missile can also include some information needed to cancel relay guidance, such as compensation information for the current target's relative trajectory deviation or trajectory change information. This allows the gun-launched missile to improve its homing accuracy against high-speed moving targets (such as armed helicopters and high-speed light vehicles) or reduce the difficulty of terminal guidance technology, while delaying the activation of the missile's active seeker as much as possible. Unlike the US military's two-way radio data link relay guidance, the UAV uses a coded laser with an extremely short duration and low data volume to send a one-way activation guidance signal to the missile, which can greatly reduce or even eliminate the power consumption of the missile's two-way data link communication and has better anti-jamming performance. Although the control method of this patent does not belong to the narrow definition of direct terminal control proximity attack, it does belong to the terminal control activation of the gun-launched missile to enter the terminal guidance proximity attack (or fly-by attack or dive attack) mode, which is an extension of the terminal proximity attack control logic and scheme. Moreover, this patent only protects the system structure and not restricts the system's usage method, so it is disclosed in this patent as well. This is easy to understand, and it has the potential to become a cost-effective technical solution for our army's future fourth-generation tanks, armored vehicles, and self-propelled artillery to achieve ultra-long-range terminal-guided attacks that cannot be achieved with existing known technologies.

[0055] If we add a laser receiver 6 to the mother warhead (including rockets, aerial bombs, or glide bombs) carrying terminally guided munitions, and have a forward-deployed small artillery reconnaissance UAV carrying a coded laser illumination system 3 take over and control the specific location and timing of the mother warhead's activation and dispersal of the terminally guided munitions (equivalent to converting and upgrading a "timed activation terminal guidance" projectile into a "human-in-the-loop plus terminal guidance" mode), we can prevent the terminally guided munition mother warhead from missing the area where the enemy time-sensitive target 2 is located on its flight path. For example, our army can launch glide bombs or rockets that fly along a straight road. When the glide bomb or rocket approaches an enemy armored formation traveling on the road, a UAV following the enemy can fire a coded laser to control the dispersal of the terminally guided munitions, which can simulate the "reconnaissance and strike" function to a certain extent.

[0056] If the scanning mechanical system is further improved, and the coded laser illumination system 3 carried by the UAV is used to provide relay guidance for the terminally guided munition (which can be considered as a projectile 2), this would reduce or even eliminate the time required for the terminally guided munition to descend slowly via parachute and enter a steady-state spiral scan until it finally locks onto the target. This would be achieved by replacing the direct transmission of command data to a specific and relatively small fan-shaped area of ​​the target with a "N"-shaped scan instead of a spiral scan of the entire target domain. Alternatively, gliding trajectory control could be used, which would significantly improve the attack effectiveness of the terminally guided munition against time-sensitive targets. If the descent mechanism of the terminally guided munition is further improved (e.g., replacing the vortex-type rotating parachute with a directionally controllable parachute) to enable it to drift and fly for a long time with a controllable direction, then the terminally guided munition could, to some extent, replace loitering munitions, which have a short flight and control distance but a several-order-of-magnitude increase in attack success rate. This is another feasible embodiment of this patent, which will not be analyzed in detail here.

Claims

1. A terminal-controlled proximity explosive fuse setting and detonation system, characterized in that: The system includes a coded laser illumination system, comprising one or more laser illuminators mounted outside the gun barrel to illuminate a laser receiver located at the base of the projectile's head after the projectile leaves the barrel. It also includes a search and fire control system with a data link connected to the coded laser illumination system for searching and tracking targets, measuring the initial velocity of the projectile, measuring or calculating the projectile's real-time position, and calculating and transmitting coded data to the projectile. The coded laser illumination system includes a laser illuminator capable of emitting coded laser light at the target or projectile under the control of the search and fire control system. A coded communication mechanism is established between the fire control system and the projectile. The system also includes an electronic proximity fuse installed inside the projectile.

2. The terminal control proximity explosive fuse setting and detonation system according to claim 1, characterized in that: The laser receiver at the bottom of the projectile's warhead includes a lens coated or plated with one or more bandpass filter films, and a photoelectric conversion element covered by the lens; the bandpass filter film allows light frequencies that are consistent with the laser frequencies emitted by the coded laser irradiation system to shield against interference light in the combat environment.

3. A terminal control proximity explosive fuse setting and detonation system according to claim 1, characterized in that: The electronic proximity fuse is electrically connected to the laser receiver and includes a power supply module, a filter amplification circuit module, a shaping and decoding circuit module, a signal processing, storage and calculation module, a detonation module and an electric detonator. It is used to filter and amplify the weak voltage signal output by the laser receiver, shape the signal, perform digital-to-analog conversion, and calculate and store the signal. Ultimately, when the laser receiver receives the correct coded laser, it can detonate the electric detonator to achieve airburst proximity of the shell at a controlled position.

4. A terminal control proximity explosive fuse setting and detonation system according to claim 1, characterized in that: The aforementioned set of one or more laser illuminators installed outside the gun barrel. When using one set of laser illuminators, the laser illuminator also serves as an coded communication mechanism. The laser illuminator is used to illuminate the projectile and the target respectively through a set of pitch and rotation follow-up mechanisms. It can also be fixedly connected to the gun barrel to form a fixed angle. By setting the curvature of the lens to ensure the far-field divergence angle of the refracted laser beam, it can compensate for the target displacement lead in the projectile's flight path and the deviation between the projectile's trajectory and the direction when the projectile leaves the barrel. When using multiple sets of laser illuminators, at least one set of laser illuminators that can be rotated or mounted on the follow-up system must be used to track and point at the target and the projectiles located near it.

5. A terminal control proximity explosive fuse setting and detonation system according to claim 1, characterized in that: The aforementioned encoding communication mechanism is a near-field communication reader, a graphic code reader / scanner, a wireless signal writing antenna or coil, or an encoding laser transmitter. Its function is to transmit the shell's identification code data between the fire control system and the shell's electronic fuse.

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