Introduction Tanks are known as the "Kings of the Ground Battlefield." Modern main battle tanks possess powerful firepower, high mobility, and strong armor protection. For a long time, countries have primarily used tanks as offensive weapons. To meet the requirements of offensive operations, firepower has always been the top priority in tank development. Tank firepower refers to the power of all the tank's weapons. It refers to the tank's ability to quickly hit, destroy, and damage enemy armored targets, infantry anti-tank weapons, field fortifications, and personnel within normal combat distances. Tank firepower is assessed by its ability to destroy or suppress various targets in the shortest time with the least amount of ammunition consumed. The strength of tank firepower depends on two aspects: the performance of the tank's weapons themselves and the performance of the tank's fire control system. Under the condition that the performance of tank weapons is certain, the level of tank fire control technology is the key factor restricting the development of tank firepower. 1 Development and Current Status of Tank Fire Control Systems 1.1 Tank Fire Control Systems and Their Development Broadly speaking, a fire control system is a set of equipment that enables the controlled weapon to achieve maximum effectiveness. A tank fire control system is a device installed inside a tank that can quickly perform functions such as observation, aiming, tracking, ranging, providing ballistic corrections, calculating firing data, automatically loading instruments, controlling weapon pointing, and firing. It mainly consists of the following three subsystems: a. Rangefinding, aiming, and night vision/night aiming system: This system ensures that the tank can quickly detect targets, accurately measure target distances, and perform precise aiming under all weather conditions. b. Tank gun control and stabilization system: This system ensures that the elevation and azimuth angles of the tank gun are not affected by vehicle vibration when firing on the move; it also makes it easier for the gunner to operate the gun. c. Fire control computer and sensor system: This system is used to automatically correct various factors affecting the accuracy of tank gun firing, ensuring that the gunner fires exactly where they aim. These three subsystems are interconnected and are actually a comprehensive control system centered on the fire control computer. Like anything else, the development of tank fire control systems has gone through a process from simple to complex. From the end of World War II to the present, its development has gone through four stages. The first-generation tank fire control system was equipped with only a simple optical sight, relying on visual distance estimation and manual aiming angle setting, resulting in a low hit rate. In the 1950s, the second-generation tank fire control system added an optical rangefinder and a mechanical ballistic computer, improving the first-round hit probability. The third-generation tank fire control system deployed abroad in the 1960s employed an electromechanical analog ballistic computer and some trajectory correction sensors, achieving a 50% first-round hit probability at 1400m during stationary firing. However, these three generations of tank fire control systems were rudimentary and could not predict the lead time for firing at moving targets. Tanks could not accurately engage moving targets during short stops or while moving. By the late 1960s, the United States had successfully developed the fourth-generation integrated fire control system, incorporating a laser rangefinder and a hybrid analog-digital fire control computer, increasing the first-round hit probability at 2000m during stationary firing to 90%. The integrated fire control system of modern tanks is a product of advanced technology, closely related to automatic control theory, computer technology, laser technology, and infrared technology. The integrated fire control system, with a fire control computer at its core, integrates information from day and night observation instruments, rangefinders, and various sensors to calculate the gun's elevation and azimuth lead angles. The gunner and commander control the stabilizer in real time through the operating mechanism to achieve precise aiming and firing. 1.2 Current Status of Tank Fire Control Systems Currently, the integrated fire control systems equipped on main battle tanks in various countries can be divided into three types according to their aiming control methods: disturbed, non-disturbed, and command-and-control. Disturbed Tank Fire Control System In a disturbed tank fire control system, the sight is rigidly connected to the gun. When static, the aiming line and the tank gun axis are calibrated and aligned with the target. In this system, the gunner directly controls the gun through the operating device, while the sight follows the gun. Therefore, while the gunner observes the target through the sight for aiming and tracking, he is actually operating the gun. During aiming and tracking, rangefinding and target motion parameters are collected. The fire control computer then calculates the relative lead angle, i.e., the angle of deviation of the aiming line relative to the gun axis, based on the input distance, motion parameters, trunnion tilt angle, and various ballistic correction parameters. This lead angle information is then transmitted only to the sight's drive system to control the aiming line's deviation. The deviation should equal the lead, and the direction of the deviation is opposite to the direction the gun will move. When the gunner detects the aiming line deviating from the target, he manipulates the control device to re-aime the gun, thus giving the gun the appropriate lead. Once firing preparation is complete, firing can be initiated. This process of the aiming line "deviating" and "re-aiming at the target" is called the disturbance process. Therefore, this control method is called the disturbance-type. Tanks employing disturbance-type fire control systems include the British Chieftain and Challenger 1, the American M60A1, M60A2, and M60A3, the Japanese Type 74, and the Chinese Type 59D, Type 79, and Type 88 tanks. Non-disruptive tank fire control systems are an improvement upon disruptive fire control systems. Compared to disruptive systems, the main difference lies in the addition of a computer-controlled device for the gun. This device receives the lead angle information output by the computer, amplifies it, and uses it to control the turret and gun drive system (i.e., the two-way stabilizer). With this control device, the lead angle information calculated by the computer is transmitted not only to the sight drive system but also to this control device on the gun, causing the gun to automatically move to the lead position. Because the movement of the aiming line and the gun axis is simultaneously controlled by the lead angle information, and the magnitude of the movement is equal but the direction is opposite, the aiming line remains essentially aligned with the target, and the disturbance process is imperceptible. Therefore, this operating mode is called non-disruptive. Tanks employing non-disruptive fire control systems include the French AMX30B2 and AMX-40, and some improved American tanks. Command-and-control tank fire control systems (stabilized fire control systems) represent a significant development in tank fire control systems. Tanks equipped with a command-and-gun fire control system allow the gunner to observe through the sight while the tank is moving. The target and background appear almost stationary, hence the system is sometimes called a "stabilized" fire control system. Using this system, the gunner can fire while the tank is moving, requiring only one aiming maneuver. Once the gunner centers the aiming indicator on the target and fires the laser for rangefinding, the aiming line remains largely undisturbed. Simply continue aiming to fire. This capability stems from a novel control method. In this system, the sight is separate from the gun, and the aiming line is independently stabilized, serving as the system's reference. The stabilization of the aiming line is achieved by using a gyroscope to stabilize the reflecting prism within the sight. In aiming mode, a gunner uses a manual control device to drive the aiming line of the sight, ensuring it tracks and aims at the target, while the gun follows the aiming line. During firing, the fire control computer calculates the lead angle, which is transmitted only to the gun and turret transmission, causing the gun to automatically adjust to the lead angle position, while the aiming line continues to track and aim at the target. Furthermore, the command-line fire control system is usually equipped with a gun-aligned firing device. When the gun is adjusted to the required lead position, this device automatically outputs a firing permission signal. If the gunner has already pressed the firing button, the tank gun will fire automatically. Currently, most advanced main battle tanks are equipped with stabilized fire control systems, such as the Japanese Type 90 tank, the German Leopard 2 tank, the American M1A1 and M1A2 tanks, the British Challenger 2 tank, the French Leclerc tank, the Russian T-90 tank, the Israeli Merkava 3 tank, and the Italian C1 Ariete tank, among others. The new main battle tanks of China, namely the Type 88A, 88B, 88C, and WZ123, are equipped with the domestically developed command and control tank fire control system, which is commonly referred to as the "stabilized fire control system." 2. Strategies for Developing China's Tank Fire Control Technology 2.1 Developing a Large Closed-Loop Fire Control System to Improve the Hit Rate of Secondary Firing Although modern tank fire control systems consider dozens of firing preparation errors, greatly improving the first-round hit rate of tank guns, even a high first-round hit rate cannot guarantee that the projectile will hit the target at any distance. Therefore, there is a problem of second-round firing correction. Currently, the most advanced stabilized tank fire control system in China's arsenal has not solved this problem. As the engagement distance of tank guns increases, it becomes increasingly difficult to observe the impact point with the naked eye, especially when firing on the move, where the impact point may be impossible to observe. Therefore, the correction of secondary firings lacks a basis and is often made by the gunner based on their practical experience. This makes it difficult to guarantee a high hit rate for secondary firings. From a combat perspective, modern main battle tanks equipped with advanced fire control systems, engaging in alternating firefights, generally have very few opportunities to fire a third shell. In other words, if the first two shells fail to destroy the target, it is highly likely that the tank will be destroyed before the third shell can be fired. Therefore, firing first, achieving a first-shot or second-shot hit is of paramount importance. Consequently, my country's main battle tanks urgently need to be equipped with a large closed-loop fire control system. The large closed-loop control principle is a new principle developed abroad in the 1970s. It has been successfully applied to the US Phalanx naval anti-aircraft gun fire control system and tested on the HIMAG prototype of the US main battle tank in the 1990s. The large closed-loop control principle utilizes projectile tracking angle and range measuring devices to measure the miss deviation of the previous shell in real time, automatically inputting this data into the fire control computer for correction calculations of the subsequent shell. The tank gun then fires the next shell based on the corrected firing data from the fire control computer. Therefore, a large closed-loop tank fire control system essentially measures and corrects the projectile's miss deviation in real time. To apply this principle, the tank fire control system must be equipped with an automatic target tracking device and projectile tracking angle and range measuring devices, as well as a digital fire control computer. This computer can store the calculated firing data and correct the tank gun's firing data in real time based on the measured miss distance. Current research and testing abroad indicate that automatic target tracking devices can utilize closed-circuit television and thermal imagers, while projectile tracking angle and range measuring devices can employ radio positioning sensors and other photoelectric sensors. my country's latest main battle tank, the WZ123, is already equipped with a thermal imager, and radio positioning technology is mature. Therefore, China possesses the technical conditions to develop a large closed-loop fire control system, making its development not only possible but also highly realistic. Tank fire control systems employ a large closed-loop control principle, which can improve the hit rate of subsequent rounds, especially significantly increasing the hit rate against targets maneuvering at high speeds on off-road terrain. This reduces the need for automatic ballistic parameter correction sensors and manually set environmental data corrections, thus shortening the tank gun's firing preparation time. However, this requires a high rate of fire and a short projectile flight time. 2.2 Developing an automatic target tracking fire control system to automate target search, identification, and tracking. The stabilized fire control systems equipped on my country's latest main battle tanks, the 88A, 88B, 88C, and WZ123, have a relatively low level of automation. Target search and identification rely entirely on the tank crew's naked eye and photoelectric sensors, and target tracking is manually controlled by the gunner. Due to the widespread use of camouflage and stealth technologies, in future high-tech local wars, not only will it be more difficult for tank crews to search for, detect, and identify targets, but in many cases, they will need to process a large amount of information in the instant of engaging a target. This necessitates a system that integrates sensors, processors, and displays. This system can extract targets more quickly and reliably from complex and chaotic background scattering interference, enabling the crew to fire at targets faster. Furthermore, domestically produced stabilized tank fire control systems only stabilize the line of sight and the gun, while the vehicle and crew remain unstabilized. Therefore, the accuracy of target tracking after the gunner or commander identifies the target is low, especially against moving targets, resulting in large tracking errors and lengthy tracking/finishing times. If the fire control system could automatically control the line of sight to track the target after identification, it could eliminate tracking/finishing errors caused by vehicle and manual tracking instability, thereby improving the accuracy of tracking moving targets while the tank is moving and shortening the tracking/finishing time, further reducing firing reaction time, increasing hit probability, and significantly reducing the workload of the commander/gunner. Therefore, domestically produced tank fire control systems urgently need to improve their automation level to automate target search, identification, and tracking. The typical structure of an automatic target tracking fire control system is to overlay a target tracking line control system on top of the command-line fire control system. This achieves open-loop control of the main control line from target to tracking line to aiming line to gun axis, elevating the technical performance of the fire control system to a new level. In tank fire control systems, available technologies for automatic target tracking include video tracking using television and thermal imaging sensors, millimeter-wave radar tracking, and lidar tracking, but video tracking is the most mature. Video tracking utilizes visible light image sensors (i.e., television cameras) or thermal imaging sensors to capture video image signals of the target for image tracking. During the day, tracking can be performed based on the visible features of the target image; at night or in low visibility conditions, thermal imaging sensors can be used to track the target based on its thermal characteristics, achieving both day and night operation. The tracking process is as follows: The image sensor or thermal imaging sensor installed in the sight captures image signals of the target's visible or thermal features. This signal is either directly processed as a video signal or sent to a computer for image processing and analysis. The target is identified from the scene image, and after Kalman filtering to determine the position of the tracking line, the error is calculated. The aiming line is then automatically controlled to align with the target, achieving automatic tracking. Simultaneously, the image signal is sent to a display to show the target image for the commander and gunner to observe and make necessary judgments. To achieve control of the tracking and aiming lines by the automatic target tracker, relevant data indicates that both PI (proportional-integral) control and optimal control methods are used. Regardless of the method, a target state estimator is present in the control process. Its function is to perform optimal linear filtering (Kalman filtering) calculations on these variables after the computer in the automatic tracker measures the target state parameters (e.g., target velocity) based on image recognition, in order to obtain the best estimated values ​​of the target state parameters, thus effectively preprocessing the important input data of the fire control computer. The core of the automatic target tracker is image tracking. In target image tracking techniques, gate tracking and correlation tracking are the most common. Gate tracking primarily simulates image tracking, determining the target's position based on certain features within a scene image and generating a tracking signal from the identified target information. Its specific tracking principles include edge tracking and centroid tracking. Correlation tracking, on the other hand, digitizes the scene image and uses the correlation function between the current image and a previously selected template image to determine the optimal matching position between the two images, thereby pinpointing the target's location. Correlation tracking utilizes more image information than gate tracking and can be used to track relatively small targets and achieve tracking in complex background conditions, making it a more advanced tracking technique. Recently, multi-feature video tracking technology, which has gained significant attention, integrates correlation tracking with edge tracking or correlation tracking with centroid tracking into a single tracker, significantly improving the reliability of target tracking. Compared to the command-and-control fire control system, the automatic target tracking fire control system has the following advantages: a. Significantly reduced reaction time: The command-and-control fire control system relies on manual tracking and aiming, which takes a long time to track and measure the target's speed. The automatic target tracking fire control system, on the other hand, relies on an automatic target tracker for automatic tracking and aiming, resulting in a shorter tracking time and shorter time to measure motion parameters, thus reducing the system's reaction time. Test data shows that the automatic target tracking fire control system intercepts targets in only 1/5 to 1/10 of the time required for manual tracking. b. Improved hit rate for firing on the move: While the command-and-control fire control system stabilizes the line of sight and the gun, manual tracking on the move can introduce errors in target speed measurement due to vehicle movement and human factors. The automatic target tracking fire control system, however, either automatically and quickly determines the target's speed during image tracking or measures it using a speed sensor when automatic tracking is already in place. Furthermore, it employs a Kalman filter for target state estimation, which reduces measurement errors of target motion parameters and significantly improves tracking accuracy compared to manual tracking, thus significantly increasing the hit rate for firing on the move. c. Improved Tank Sustained Combat Capability: Tank manpower is the most important resource. The automation of tracking and aiming reduces the workload of the gunner. When automatically tracking a target, the gunner no longer needs to perform complex operating procedures for firing on the move; they only need to operate and monitor the automatic target tracking. This saving of manpower will inevitably promote the enhancement of the tank's sustained combat capability. The Japanese Type 90 main battle tank's fire control system has advanced automatic tracking capabilities. It utilizes the output signal of a thermal imager for automatic tracking. The automatic tracker can effectively track ground targets, especially aerial targets such as helicopters. It can be used whether the tank is stationary or moving. When not using the automatic tracker, the gunner or commander uses their manual controller to track the target. When using the automatic tracker, after acquiring a target, the gunner's only action is to press the lock switch once the target enters the tracking door of the sight. If the target is temporarily lost (when it moves behind cover), the sight will continue tracking at the same speed. When the target reappears, the gunner can quickly re-lock on the target and begin automatic tracking again. Currently, besides Japan's Type 90 main battle tank, which has automatic target tracking capabilities, Israel's Merkava 3 main battle tank is also equipped with an automatic tracker. These represent the future direction of tank fire control development and have the potential to replace command-lined tank fire control systems. 2.3 Developing integrated fire control systems combining high-altitude and low-altitude capabilities, and integrating missiles and guns, to improve the air-launched and long-range combat capabilities of main battle tanks. In future high-tech local wars, the threats to main battle tanks will not only come from ground-based anti-tank weapons, but also from the air, which is arguably even greater. Especially given the current emphasis on the development and operational application of armed helicopters by various countries, this undoubtedly poses a fatal threat to tanks. Anti-tank armed helicopters possess unique flight capabilities, superior maneuverability, good visibility, and powerful firepower systems. They have long-range (6000m-7000m) attack capabilities and fire-and-forget automatic homing missiles. For example, the French Gazelle attack helicopter equipped with the HOT missile has an 81% hit probability against tanks and a 100% probability of destroying them. The US military's AH-64 attack helicopter is equipped with a 30mm cannon, 16 anti-tank missiles, or 4 rocket launchers or air-to-air missiles. Multiple simulated combat tests conducted by the US, UK, France, Russia, and other countries have shown that the loss ratio between anti-tank attack helicopters and tanks is generally between 1:14 and 1:20, with an average of 1:17.3 and a maximum of 0:20. Attack helicopters have become the natural enemy of main battle tanks. Therefore, the air-to-air capability of our main battle tanks urgently needs improvement, as relying solely on the 12.7mm tank anti-aircraft machine gun is insufficient for air defense missions. Developing an integrated fire control system capable of both ground attack and air-to-air engagement is crucial to improving the air-to-air capability of main battle tanks, thereby enhancing their battlefield survivability. This is not only a necessity for the development of tank fire control systems but also for winning future local wars under high-tech conditions. The integrated gun-missile system solves the problem of close-range tank gun firing while improving the long-range combat capabilities of main battle tanks (air and ground attack capabilities). Through this combination of close and long-range engagements and the complementary nature of gun-missile systems, the overall combat effectiveness of tanks can be greatly enhanced. Therefore, future development should focus on multi-functional tank fire control systems, striving to achieve a combination of high-altitude and low-altitude fire, curved and straight-line fire, and gun-missile integration. To improve the long-range combat capabilities of its main battle tanks, the Russian army has consistently adhered to the principle of multi-purpose guns and integrated gun-missile systems. The 125mm 2A46A1 smoothbore gun on its T-90E main battle tank can fire both conventional shells and laser-guided AT-11 "Sniper" anti-tank missiles, with an attack range of up to 5000m. The 125mm smoothbore gun on the T-80 main battle tank can fire both conventional shells and AT-88 (Singer) radio command guided, semi-autonomous command wire-aiming gun-launched missiles, with a maximum range of 4000m. Furthermore, the T-72 and T-62 main battle tanks are also equipped with gun-launched missiles, a technology that is quite mature. These missiles are not only compatible with the tank's automatic loader but also possess high flight speeds, thus effectively countering tanks with explosive reactive armor and attacking helicopters, significantly increasing the tank's air-to-air and air-to-ground attack range. The US military's XM872 rocket-assisted smart kinetic energy penetrator, developed for the M1A1 and M1A2 tanks, can extend the attack range to 10km, while the XM943 smart target-activated fire-and-forget (STAFF) projectile enables indirect fire and attacks on concealed targets, as well as attacks on the target's top armor. This demonstrates that major world powers place great emphasis on improving the long-range combat capabilities of their main battle tanks. 2.4 Developing CO2 Laser Rangefinders to Improve Tank All-Weather Combat Capability 2.4.1 Deficiencies of Nd:YAG Laser Rangefinders Currently, the laser rangefinders equipped on my country's main battle tanks are all Nd:YAG laser rangefinders, belonging to the second generation of laser rangefinders. Their wavelength is 1.06μm, which is invisible near-infrared light. Compared with the first-generation ruby ​​laser rangefinders, it has higher electro-optical conversion efficiency, lower threshold, can operate at high repetition frequencies, lower power consumption, smaller size, and stealth capabilities, thus gaining widespread application and becoming the main military laser rangefinder widely equipped by the army, navy, and air force. However, Nd:YAG laser rangefinders have the following three serious defects: ① Significant damage to human eyes. The laser energy emitted by Nd:YAG laser rangefinders can be focused onto the retina through the human eye, causing blindness at close range and damage at long range, thus bringing great difficulties to training and testing. ② Low all-weather ranging capability. The 3–5 μm (mid-infrared) and 8–14 μm (far-infrared) wavelength ranges represent two atmospheric windows for infrared radiation. However, the Nd:YAG laser rangefinder produces a 1.06 μm laser, which is outside these infrared atmospheric windows. Therefore, its propagation in the atmosphere is low and it is easily interfered with. In foggy, hazy, or battlefield dusty environments, not only can the accuracy and quality of ranging be compromised, but ranging may even be impossible. This means that the Nd:YAG laser rangefinder is greatly affected by visibility, reducing the all-weather combat capability of main battle tanks. ③ Poor compatibility. my country's new WZ123 main battle tank is already equipped with a thermal imager. To improve the night combat capability of the PLA's armored forces, thermal imagers will inevitably be deployed in large numbers in the future. Since the operating wavelength of thermal imagers is 8–12 μm, the 1.06 μm Nd:YAG laser rangefinder has poor compatibility with them. Because they operate in different wavelength bands, not only can components and parts not be shared, but targets that can be observed by a thermal imager may not be measurable by an Nd:YAG laser rangefinder (because thermal imagers have a strong ability to penetrate smoke, fog, snow, and dust, while Nd:YAG laser rangefinders have a lower penetration capability). Therefore, it is necessary to further develop new tank laser rangefinders with higher energy conversion efficiency and output power, and which are safer for the human eye. The CO2 laser rangefinder is one such laser rangefinder that meets this requirement. 2.4.2 Advantages of CO2 Laser Rangefinders Compared with the 1.06μm Nd:YAG laser rangefinder, the 10.59μm wavelength CO2 laser rangefinder has the following outstanding advantages: ① Strong transmission capability The operating wavelength of the CO2 laser rangefinder is 10.59μm, which falls within the 8-14μm far-infrared atmospheric window. Therefore, it has good atmospheric transmission performance, strong ability to penetrate atmospheric fog, haze, and battlefield smoke, and visibility has little impact on it. ② Eye Safety: The 10.59μm wavelength of low-power CO2 lasers is far from the transmission wavelength of the eye (visible and near-infrared bands). It is absorbed by the cornea and does not damage the retina, thus it will not damage or blind the irradiated eye. During training and exercises, there are no safety restrictions, and it is not necessary to wear protective glasses or install protective filters inside the instrument. ③ Good Compatibility with Thermal Imagers (Operating Wavelength 8-12μm): CO2 laser rangefinders and thermal imagers can share optical systems, scanning systems, receivers, and power supplies, resulting in a compact, smaller, lighter, and less expensive combined system. Furthermore, they are compatible in performance. ④ High Efficiency: The efficiency of lamp-pumped Nd:YAG lasers is generally 1-3%, with a maximum of no more than 5%, while the efficiency of CO2 lasers is generally 10-20%, and can reach up to 25%, thus reducing the overall weight and size of the device. Currently, the world's most advanced main battle tanks are equipped with CO2 laser rangefinders. Examples include the US M1A1 and M1A2, the South Korean Type 88, and the British Challenger 2. The excellent performance of CO2 tank laser rangefinders was fully demonstrated in the Gulf War, and it can be predicted that CO2 laser rangefinders will gradually replace Nd:YAG laser rangefinders. 2.5 Integrating the Tank Fire Control System into the Vehicle's Integrated Electronic System: Modern tank fire control systems have numerous electronic components and electrical systems, resulting in complex and intricate wiring within the vehicle. This not only occupies a significant amount of space but also reduces its protective performance and reliability. Integrating the tank fire control system into the vehicle's integrated electronic system—that is, using a data bus as the backbone to connect all electronic and electrical systems into a unified system, while reserving interfaces for future electronic systems—integrates target detection and tracking, gun control, automatic ammunition loading, component condition monitoring, various information acquisition and transmission, battlefield command and control, positioning and navigation, and more. This fully utilizes system redundancy to improve the reliability of each subsystem and the entire system, and leverages the high speed of digital transmission to shorten reaction time and improve confidentiality. By rapidly transmitting information, the combat effectiveness of each combat unit can be fully mobilized to improve overall combat effectiveness. The French Leclerc tank is designed according to this integrated vehicle electronic system concept. Its electronic equipment is configured around a digital data bus, with approximately 30 8-bit, 16-bit, or 32-bit microprocessors used to control and test the operation of various components. Through the data bus, devices can continuously exchange data, and the system structure can be rearranged when components malfunction or are damaged. The Leclerc tank's vehicle electronics system enables the crew to transmit critical information to other tanks and higher command levels, and also to receive information from them. This information includes the tank's coordinates, the size and location of detected enemy forces, ammunition and fuel reserves, the operational status of the tank's fire control system, and other systems. The U.S. Army has deployed the Inter-Vehicle Intelligence System (IVIS) on the M1A2 main battle tank. IVIS functionality is implemented through software running on standard vehicle electronics hardware modules. Communication between components is via a dual-redundant military standard 1553B data bus. Fault management software allows one device to replace another that has malfunctioned. For example, if the turret electronics of the fire control system fail, the hull electronics can take over the bus controller function and provide ballistic calculations for the fire control system. Additionally, the U.S. M109A6 155mm self-propelled howitzer, the M2A3 armored vehicle (an improved version of the M2A2 Bradley), and the XM8 armored fighting vehicle's gun system are also equipped with vehicle electronics systems. The digital tanks of our army's armored forces' digital experimental unit are also equipped with a vehicle integrated electronic information system. This system connects the vehicle's main computer, communication equipment, fire control system, propulsion, protection, and other electronic systems via a data bus, enabling information transmission and distribution. Externally, it forms an information network with the company and battalion; internally, it collects workshop information and controls relevant equipment. In summary, integrating the tank fire control system into the vehicle integrated electronic system is the future development trend of main battle tank fire control systems, and the vehicle integrated electronic system is an indispensable core component of digital tanks. It not only improves the reliability of the entire vehicle system but also has good scalability, reduces the workload of tank crews, and facilitates connection with the entire battlefield C3I system, making it a future development direction. 2.6 Developing Standardized, Modular, and Miniaturized Tank Fire Control Systems Main battle tanks are both the assault force on the land battlefield and the target of numerous anti-tank weapons. Therefore, main battle tanks are highly vulnerable to attacks from ground and air weapons. The various electronic components and connecting cables of the tank fire control system are also easily damaged; once a tank is hit, damage to the fire control components is inevitable. Standardization and modularization of tank fire control systems facilitate peacetime maintenance and wartime logistical support, saving manpower, material resources, and financial resources. It also improves the reproducibility of the fire control system, thereby enhancing the combat effectiveness and survivability of main battle tanks. Furthermore, the widespread application of various high-tech weapons and equipment on main battle tanks has led to increasingly cramped interior space. Miniaturization of the fire control system can help alleviate this growing problem, providing tank crews with greater freedom of movement and creating a more favorable environment and conditions for fully utilizing their combat capabilities. About the authors: Zhu Yinggui, male, born in 1958. Associate Professor, Master's Supervisor. Member of the Chinese People's Liberation Army Shooting Society, Editorial Board Member of the *Journal of Shooting*. Graduated from Bengbu Tank Academy in 1980, currently engaged in teaching and research on the theory and practice of tank firepower application. Kong Fanqing, male, born in 1963, Lecturer, graduated from the Chinese People's Liberation Army Armored Forces Engineering Academy in 1986, engaged in teaching tank structure, theoretical research on tank fire control systems, and equipment maintenance. Li Bingzhi, male, born in 1963, graduated from Nanjing Army Academy in 1987, and is currently a lecturer at the Tank Academy. References: 1. Yang Peigen et al. Ordnance Industry Intelligence Research Report. Beijing: Ordnance Industry Intelligence Research Institute, 1994. 2. General Staff Armored Forces Department. Foreign Tank Fire Control Systems and Components. Beijing: PLA Publishing House, 1984. 3. Zhou Qihuang et al. Tank Fire Control System. Beijing: National Defense Industry Press, 1997. Editor: He Shiping