The launch of the Mars ascent vehicle(MAV) is the first step for ascent from the Martian surface to orbit around Mars, a critical step in the Mars sample return mission. In the MAV's inclined hot launch process, the force-thermal impacts are significant and gas flow structure is complex, so when designing its launch system, it is necessary to consider the complex force-thermal effect in launching process. This study employs computational fluid dynamics to conduct a numerical simulation of the force-thermal impacts of the MAV's inclined thermal launch on the Martian surface, with comparisons to similar launch conditions on earth. The findings reveal that during the inclined hot launch from Mars, the MAV's maximum surface temperature reaches 2 868 K, while the launch platform attains a peak temperature of 2 908 K. Furthermore, during ejection, the platform's pitch-up moment progressively increases, the launch apparatus may topple under Mars' low-gravity conditions. Notable differences are observed between inclined hot launch processes on Mars and Earth; the MAV launch on Mars exhibits greater stability yet endures more severe force-thermal impacts on both the platform and the MAV.

In order to study the influence of the missile ejection condition in initial phaseon the deploying process of folding rudders, ADAMS is used to analyze the dynamic response of a torsion bar folding rudders without mechanical limit structure. The actual structural dynamic performance of the folding rudders is obtained through the observation of the folding rudders deploying test on the ground by mean of high-speed photography, and the model parameters of the dynamic simulation are modified according to the experimental results. Considering the impact of missile body attitude variations during aerial ejection on the folding rudders deploying process, the ejection force of the ejection device on the missile is measured by the ejection test on the ground, and CFD simulation is used to calculate the time-varying aerodynamic force experienced by the control surface of the rudders when they are deployed under the complex flow field of the plane belly, a dynamic deployment model for the rudders is established, which involving both ejection device force and aerodynamic resistance. The failure risks of folding rudders deployingt process are analyzed under multiple external folding rudder unlock time conditions and aerodynamic force deviations. Based on simulation results, a reasonable design range for external folding rudder unlock time is proposed. This work provides valuable reference for the engineering design and application of folding rudder.

Liquid propellant sloshing alters the rocket's center of mass and generates dynamic loads on storage tanks, adversely affecting launch stability and safety. Aiming at the coupling problem between attitude deviation and liquid sloshing during the multi-stage piston eccentric ejection process of liquid rockets, a fluid-structure interaction model of the liquid rocket and its launch system was established by using the finite element method and smooth particle hydrodynamics method (FEM-SPH). The entire eccentric ejection process of the liquid rocket was simulated and analyzed, and the influence of the number and spatial distribution of the liquid rocket adapter on the initial disturbance of the rocket, the force on the rocket tank and the force characteristics of the adapter itself was investigated. The results indicate that the eccentric ejection of a liquid rocket induces deviations in the rocket's yaw angle. During the ejection process, the lateral sloshing loads on the oxidizer tank exceed those on the fuel tank at the same stage, and the force variations on the first-stage adapter located in the upper section of the rocket are more pronounced. When the adapters are distributed in a sparse upper and dense lower configuration, the rocket's yaw angle and the force variation on the adapter are the largest. When the adapters are arranged in a dense upper and sparse lower configuration, the peak sloshing forces on all tanks are the highest. Increasing the adapter from four to six circles reduces the rocket ejection yaw angle by 26.9%, the peak value of lateral slosh force on each tank by an average of 24.1%, and the change in force on the first adapter by 34.6%.

During the hot launch process of a carrier rocket, the high-temperature and high-pressure gas generated by the rocket engine will cause significant high-temperature erosion on flame division trough. In order to achieve the thermal protection of the division trough during launch of a rocket, the variation of the flow field during water injection onto the surface of a single-sided division trough was analyzed based on the computational fluid dynamics (CFD) method with coupled mixture multiphase flow model and Lee model for different water injection velocities for a rocket with two booster stages. The results show that spraying water into the division trough effectively suppresses the phenomenon of gas splashing, significantly reduces the distribution area of the high-temperature zone on the surface of the division trough, and provides good protection for the division trough. When the water spraying speed is low, it will cause oscillation of the maximum temperature on the surface of the division trough. As the water spraying speed increases, the degree of oscillation of the maximum temperature on the surface of the division trough gradually weakens until it disappears. As the water spraying speed increases, the maximum temperature on the surface of the division trough decreases, and the maximum vaporization rate also increases. Spraying water onto the gas jet will change the shape of the flow field. Different spraying positions will result in different distributions of physical parameters along the axis of the gas jet. Directly impacting the gas jet with the water jet will have a better cooling effect. This conclusion can provide some reference for the launch process of carrier rockets.

In order to study the hot launch shock wave opening process of small launcher, a numerical simulation of the process is carried out by using CFD-FASTRAN aerodynamic analysis software. According to the calculation results analysis, it gives the changing process of surface temperature and pressure of main components affects by gas shock wave in the process of hot launch shock wave opening of small launch tube. The whole process of hot launch shock cap opening is analyzed by using CFD-FASTRAN pneumatic analysis software innovatively, and the influence of the distance between nozzle and back cap and the expansion angle of nozzle on the shock cap opening process is systematically analyzed for the first time. The results show that the pressure decreases from edge to center and the temperature increases from edge to center under the influence of gas jet. The shock wave reflected by the gas flow moves along the axis of the launch tube towards the warhead, and the pressure and temperature on the wall of the launch tube gradually decrease with the direction of the shock wave. The temperature and pressure of the front cover are weakened from edge to center by the gas shock wave influence. The increase of the distance between the nozzle outlet and the rear cover and the increase of the expansion angle of the nozzle can enhance the total energy reflected by the shock wave to the front cover, and shorten the opening time of the shock wave. The calculation and simulation method can provide a reference for the strength design and structure design of the front and back covers of the small launch tube with hot launch shock wave.

In view of the fact that the existing research has not systematically revealed the scientific issue of the dynamic response of the unanchored launch system to road damage, this study based on the dynamic model of the underground cavity-damaged road and the unanchored mobile launch system, analyzes the influence of the spatial distribution of cavities on the coupled system. The results show that the cavity damage causes the road to undergo brittle fracture, and the maximum deflection of the road increases by 23.5%. However, the initial disturbance of the missile decreases by 21.5% due to the road damage. When the cavity shifts longitudinally, the maximum deflection of the road first increases by 3.36% and then gradually decreases. When the cavity shifts towards the rear of the vehicle, the initial disturbance of the missile first increases by 42.1% and then gradually decreases. When the cavity shifts towards the front of the vehicle, the initial disturbance of the missile monotonically decreases by 28.95%. When the cavity shifts laterally, the maximum deflection of the road first increases by 14.33% and then decreases by 22.76%, and the yaw rate of the missile increases from 0.001°/s to -0.091°/s and then decreases to -0.049°/s. The depth parameter of the cavity has a relatively small influence on the coupled system. With the increase in the size of the cavity, the maximum deflection of the road increases by 47.65%, while the initial disturbance of the missile first decreases by 21.8% and then gradually increases due to the road damage.

In order to improve the detection ability of infrared small targets in complex backgrounds, a small infrared target detection algorithm based on joint gradient discrimination and adaptive matching was proposed. The suspected target area is screened out for the first time in the image through multi-directional gradient features, and the adaptive model is generated by using the grayscale information in the region for re-judgment. Quantitative evaluation was established for gradient judgment and adaptive model matching, and confidence functions were introduced to evaluate different suspected target areas and screen out suspected targets. In order to enable the algorithm to be applied in dynamic platforms such as UAVs, an embedded system was built to realize the detection of small targets in real scenes by the detection system through infrared camera framing. By testing different public datasets and comparing with WSLCM (weighted strengthened local contrast measure) and TLLCM (tri-layer local contrast measure) algorithms in different complex scenarios, the proposed algorithm has good adaptability, and the recognition rate under different samples is more than 92%. The algorithm is processed by hardware acceleration through the customization of the IP core of the embedded platform and the co-design of software and hardware, and the real-time video frame rate is greater than 30 frame/s, which verifies its effectiveness.

Cold launching of rocket is a kind of launching method by means of the gas generator in the launching tube to catapult the rocket out of the launching tube, and then ignite the main engine after the projectile body leaves the tube. In order to ensure that the rocket can get enough muzzle velocity at the end of the cold launching process, a structure of the cold launcher is designed and improved, and the internal ballistic characteristics during the launching process are studied, then a two-dimensional axisymmetric model of rocket cold launcher is established. It adopts layer spread dynamic grid technology and fluid control equation to numerically simulate the internal flow field of the launcher under the same propellant quantity and different working time, and obtain the pressure inside the launcher and the motion characteristic curves of the projectile body under different working conditions. The simulation results show that under the condition of the same mass of the propellant column, the increase of the working time of the gas generator will lead to the extension of the rocket discharge time and the decrease of the discharge speed, but it will also reduce the peak pressure and acceleration in the launching tube, the rate of change in the acceleration of the rocket is more stable, and the rocket overload will be reduced during the launching process.

A three-dimensional simulation model is established to investigate the impact of engine gas flow on the fragile front cover of surrounding launch tube during the process of a missile leaving its launch tube matrix. The dynamic grid method is used to simulate the motion of the missile body, and the transient flow field on the surface of the surrounding front cover is numerically simulated and calculated. By analyzing the gas streamline and flow field contours, the influence of the engine expansion and compression wave on the airflow direction and pressure distribution on the surface of the front cover during missile motion is obtained. Based on the changes in pressure difference between the inside and outside of the front cover at different times, combined with the safe range of pressure difference obtained from experiments, it assists in determining whether the front cover will rupture prematurely. By changing the distance between adjacent launch tubes, the magnitude of the change in pressure difference between the inside and outside of the front cover is calculated, and the safe distance between launch tubes is obtained. This provides simulation prediction and data support for the structural optimization design of the front cover and the arrangement scheme of multiple launch tube units.

For the tube-launched missiles carried on air based platforms, the launchers equipped with traditional flat sealing film lead to unavoidable issues that aerodynamic drag increases and broken fairing threatens the safety of aircraft. To address the problem, the influences of the aspect ratio of ellipsoidal fairing and aircraft cruising speed on its aerodynamic characteristics are studied. The relationship between fairing aerodynamic moment and increment of rotation angle is established. Based on the model of twins torsional spring, a fairing mechanism with tandem torsional springs is designed. The analytical model for the contact force of fairing adapter and its contact point parameters is established to obtain the optimal contact point and the minimum contact force. As a result, a multifunctional fairing mechanism is proposed which is capable of reducing aerodynamic drag, nondestructively opening, reducing contact force and automatically resetting itself. The analysis results of the virtual prototype indicate that the dynamic contact force of the adapter and the reset time are respectively 224.0 N and 17.7 ms, it verifies the rationality and feasibility of the mechanism. The proposed method has important reference significance for the design of launch tube fairing of tube-launched missiles equipped on aircraft platform.

It is difficult to accurately test overload of a projectile moving in a bore by conventional testing methods and the strong electromagnetic environment interferes with the testing devices in electromagnetic launching, a new method for testing the overload of the projectile in the bore is proposed. Firstly, based on the technical advantage of electromagnetic launching technology that the overload in the bore is adjustable and controllable, a testing principle for projectile overload test is put forward, that controls the current waveform and makes it into a flat wave, then establishes a constant overload loading interval to test projectile overload. Secondly, a new test method of the projectile overload, that is launched by electromagnetic rail, is established. By controlling the current loading waveform and changing the current amplitude, the corresponding relationship between the overload and the current is established, and through electromagnetic launching test, it can get the loading current and corresponding relationship and indirectly get overload of the projectile in-bore. Finally, the electromagnetic launching test is carried out, and the conventional test method and the new test method are compared. The results show that the new test method can complete the overload loading process test of the whole inner bore, and can more truly reflect the process of the projectile starting to move after overcoming the static friction. This test method can meet the requirements of in-bore overload test of electromagnetic projectile, and avoid the influence of electromagnetic interference on the test.

The gas jet generated during rocket launching has a strong impact on the launching platform and may cause great damage to the launching platform. Therefore, it is necessary to study the impact effect of gas jet, researching the the wake field of rocket under different elevation angles. Based on computational fluid dynamics method, a finite volume method is used to discrete the rocket wake fields, and mathematical physical models of wake fields at different elevation angles are established for numerical simulation. Within the range of high and low angle adjustment, five angles of 0°, 5°, 15°, 28° and 38° are selected for simulation. By analyzing the distribution of jet velocity and pressure with the change of elevation angles and time, the development law of jet under different elevation angles can be obtained. Based on the analysis of the wall pressure distribution and maximum pressure variation, the impact effect of jet on the launching platform under different elevation angles can be obtained. The research results show that the wall pressure tends to increase with the increase of the elevation angle. And when the elevation angle is greater than 15°, the wall pressure will increase greatly. Each position of the launch platform is affected by jet impact to different degrees, and different protection strategies need to be adopted. The research provides theoretical support for the launch platform protection design.

　　航天发射技术是研究运载火箭、各类飞行器等的发射原理、发射方式和发射设施设计、制造、试验和使用的工程科学技术，是航天技术的一个分支和重要组成部分，是一门综合性、系统性极强的学科方向。航天发射技术的发展水平决定了一个国家航天活动和国防保障区域的范围，反映了一个国家工程科学和基础工业的综合水平。
　　近年来，为适应航天运载工具的快速发展，全球航天发射技术正朝着规模化、复杂化、自动化与国际化的方向迈进。我国航天发射技术也获得了长足的进步，取得了丰硕的成果，如海南发射场的建成有力保障了我国未来各类航天任务的开展；以“长征-11”运载火箭为代表的机动航天发射技术的出现为我国应急航天发射任务提供了多元化发射手段。这些进展不仅彰显了我国航天技术的创新实力，也为未来深空探测、商业发射和国防需求奠定了坚实基础。
　　当前，各航天大国均把发展先进的发射和运载技术作为保持其在航天领域领先地位的战略部署之一。无论是空间应用、科学探测、载人航天、国际商业发射与国际合作，还是国防建设，都对发射技术提出了新的要求，亟待发展规模更大、成本更低、兼容性更强、可靠性更高、发射周期更短、更加智能的大型航天发射场；随着航天发射任务的大幅增加和各类应急发射需求的大量涌现，提出了发展快速机动的低成本航天发射方式；面向低碳、绿色、高效、低成本发射的需求，提出了地面超高速发射一级直接入轨等新型发射概念；此外，深空探测任务的推进，使得地外天体发射技术成为前沿研究热点。
　　在此背景下，《弹箭与制导学报》编辑部联合北京理工大学姜毅教授团队，策划推出本期“火箭导弹发射技术”专刊，旨在汇聚领域内最新研究成果，推动学术交流与技术突破。本期专刊特邀姜毅教授(北京理工大学)、姚建勇教授(南京理工大学)担任编审，共收录18篇高质量论文，内容涵盖发射技术理论创新、工程实践及未来发展趋势，以期为国家航天事业发展提供有益参考。
　　我们谨向所有参与本专刊撰写的专家学者致以诚挚谢意，也期待本期专刊能为航天发射技术的进步注入新动力，助力我国迈向航天强国的宏伟目标。

Transonic shock oscillations and cavity flows are both primary contributors to the intense pulsating pressures and structural vibrations in laterally maneuverable rocket missiles. However, existing studies have predominantly focused on single flow characteristics impacting on the wall load environment, while neglecting the coupling effects between two unsteady flow phenomena. This oversight poses potential risks to the flight safety of aerospace vehicles under specific flight conditions. In this study, a rocket fairing and a sidewall cavity structure are employed as the research subjects. The Delayed Detached Eddy Simulation (DDES) method is utilized to conduct a numerical investigation into the flow field characteristics and the time-frequency properties of pulsating pressures in the presence of both transonic shock oscillations and cavity flows, aiming to explore the coupling mechanisms between shock oscillations and cavity flows. The research findings indicate that cavity flows reduce the effect of separated flows on the shock, thereby weakening the intensity of transonic shock oscillations, while shock oscillations stabilize the cavity flow field, significantly lowering the sound pressure level (SPL) on the cavity walls, maximally, which can reach up to 30 dB at Mach 0.95. Based on the flow dynamics cognition in coupled transonic flow fields, 3 flow control strategies for the coupled flow field are designed. Comparative results reveal that a steep rise in leading edge of the cavity promotes the mutual inhibition of shock oscillations and cavity flows, thereby reducing the pulsating pressure levels on the cavity walls. The analysis of the coupled flow field involving transonic shock oscillations and cavity flows provides valuable support for the development of next-generation aerospace vehicles.

Rolling linear guides, known for their precise guidance and dynamic stability, are widely used in rocket and missile weapon launch transmission systems. Due to differences in functional adaptability, multiple sets of rolling linear guides are involved in the same launch system. To achieve efficient modeling, simplify the design process, and accelerate the product design iteration cycle for different purposes and models of rolling linear guides, this paper proposes a dual-drive parametric design system that integrates dynamic and static characteristic simulation analysis results with the engineering design experience of the engineers. The system extracts key structural parameters that affect the performance of the components, redevelops the Abaqus finite element software using the Python language and take multiple models of rolling linear guides as examples to establish a parametric modeling method for the rail pair. The results of typical test cases show that, based on the dual-drive parametric design system and using the Python-Abaqus parametric modeling method, a parametric model with adjustable geometric parameters can be established. This method creates a three-dimensional model of the rail pair with a geometric error of less than 0.3% in under 4 seconds.

The rapid separation characteristic for a sabot from its integrated launch projectile has an important impact on the projectile firing accuracy, and is one of the main design requirements about sabot. In order to improve the separation performance of the sabot, an unsteady CFD method based on six degrees of freedom equation coupled with URANS equation is created for the separation calculation of the sabot, and a surrogate optimization framework for the shape of the windward nest of the sabot is constructed based on Kriging model and genetic algorithm. A 16 degree compression corner example is used to verify the reliability of the CFD method by comparing with the experimental values. The shape of the optimized windward nest is obtained by surrogate optimization method, and the flow field and separation characteristics of the optimized sabot are compared with the initial sabot, which reveals the aerodynamic mechanism of the improved separation performance of the optimized sabot. The results show that the decrease of the pressure on the inner surface of the optimized sabot is significantly less than that of the initial sabot during the separation process, while the pressure on windward nest of the optimized sabot is basically the same as that of the initial sabot. Therefore, the overall separation force of the optimized sabot is significantly increased, with the transverse separation displacement increases by 14.86% and separation pitching angle increases by 13.75%, and the separation performance is improved.

The visible light image of the rocket emitted at night provides clear texture and color information of the tail flame, while the infrared image offers a complete outline of the arrow body and saturated tail flame. Due to the high complementarity between the two, fusion of visible and infrared images has been a focal point in research aimed at enhancing rocket imaging observation capability at launch sites. This paper introduces a fusion method for nighttime visible and infrared images based on rocket tail recognition and region reconstruction. In this method, the invariant features of the arrow body are used to search for the tail secant line, which is then utilized to divide the region. Finally, a fusion strategy for region reconstruction is employed to merge the infrared arrow body with the visible tail flame. This approach effectively prevents loss of feature information from both types of images and maximizes semantic information fusion. Experimental results demonstrate that compared with current main image fusion methods, our proposed method significantly improves fusion effectiveness while better preserving feature details from both visible and infrared source images. Furthermore, it achieves quasi-real-time effects within a short time frame.

Loitering munitions integrate multiple functions such as reconnaissance, attack, and assessment. They have low usage costs, flexible combat deployment, and are difficult to detect and intercept. They have significantly enhanced the strike accuracy and ability against targets and have become important weapons in the Russia-Ukraine conflict, attracting great attention from major military powers. This paper summarizes the characteristics of loitering munitions, introduces the development status of major loitering munitions at home and abroad, including the “Switchblade” series and “BattleHawk” series of the United States, the “KUB” series and “Lancet” series of Russia, and the “Hero” series and “Harpy” series of Israel, which have practical applications. It comparatively analyzes the performance parameters of relevant loitering munitions, combs the key technologies in the development of loitering munitions, including power technology, anti-interference technology, modular technology, and intelligent cooperative combat technology, summarizes the development trends of loitering munitions, and on this basis, analyzes the combat applications of loitering munitions and the defense means against them.

To address the practical challenges of nonlinear dynamic modeling in missile hydraulic erection systems, as well as the presence of mechanical and hydraulic dynamic uncertainties, this study proposes an incremental nonlinear dynamic inversion (INDI) control method. The proposed approach reduces the reliance on complex nonlinear hydraulic models, offers strong robustness, and enables a concise and efficient controller design with a clear structure. First, a dynamic model of the valve-controlled cylinder-driven system is established, and a virtual control law for the hydraulic channel is constructed using the backstepping method. Then, a first-order Taylor expansion is applied to decouple the nonlinear hydraulic dynamics, based on which an INDI controller is designed to track the virtual control law and achieve accurate missile erection trajectory tracking. The stability of the closed-loop system is proven using the Lyapunov theory. Comparative simulations provide further evidence supporting the effectiveness of the proposed controller.

To ensure that the UAV (unmanned aerial vehicle) can accurately locate the reconnaissance target, image matching plays a critical role in the localization process, and its performance directly affects the localization accuracy of the targets. However, UAVs often encounter challenges when performing reconnaissance tasks in complex environments, especially when background information is similar, which hinders the effective elimination of a large number of outliers. This paper proposes an improved RANSAC (random sample consensus) algorithm. First, an initial dataset is constructed using triplet relationships. Based on these relationships, an improved strategy for selecting initial data is proposed, which reduces computational costs and improves matching accuracy through neighborhood-based geometric consistency and triangulation. Second, a data subset refinement strategy is introduced to further enhance the algorithm's sampling performance. Finally, the proposed algorithm is compared with other advanced algorithms on UAV reconnaissance image datasets featuring complex environments and similar background information. Experimental results demonstrate that the proposed algorithm achieves higher computational efficiency and correct matching rates, thus improving both the computational speed and localization accuracy, providing a novel method for UAV reconnaissance target localization.

Infrared tracking of small and weak targets is an indispensable technology in anti-unmanned aerial vehicle systems. The small size, low contrast, strong maneuverability, and complex background of unmanned aerial vehicles pose lots of difficulties and challenges to tracking algorithms. To address these issues, an improved visual tracking Siamese fully convolutional classification and regression network (ISIAMCAR) is proposed. Initially, a side window filter is incorporated into the model to enhance the feature extraction capabilities of the deep convolutional neural network for small targets within the original network. Additionally, a location-aware module is integrated into the network to maintain the efficient propagation of deep convolutional features for infrared weak and small targets detection and tracking, thereby improving the classification and regression capabilities for infrared small and weak targets. The visual and numerical experimental results demonstrate that our approach outperforms existing state-of-the-art methods, achieving the highest tracking success rate and precision rate. Furthermore, the typical computational time of our proposed model has been thoroughly tested, and the ISIAMCAR network we designed meets the real-time requirements of the target tracking task in the anti-unmanned aerial vehicle system. Finally, ablation experiments have been designed and conducted to verify the effectiveness of the side window filtering and location-aware module in the proposed model.

In view of the problem that the infrared imaging for terminal guidance of rockets is affected by aerodynamic heating, the temperature response of the sapphire infraredwindow structure caused by aerodynamic heating is obtained through numerical simulation. On this basis, a wind tunnel test is designed to study the effect of aerodynamic heating on the infrared imaging of the seeker. In the numerical simulation, the aerodynamic heating of the infrared dome along the ballistic trajectory is obtained by combining computational fluid dynamics and engineering algorithms, and the temperature response of the dome structure is obtained by the finite element method. In the wind tunnel test, measuring points are installed on the inner surface of the dome to obtain the temperature response of the dome structure under aerodynamic heating, and the imaging effect of the infrared seeker under aerodynamic heating is tested. The research results show that, under aerodynamic heating, the highestinner wall temperature of the dome is 148 ℃, which is much higher than the target temperature of 27 ℃. Based on the sapphire window temperature, it needs to reduce the integration time of the infrared detector and adjust imaging algorithmto perform image correction.

In view of the technical difficulties such as unstable and target loss in the process of tracking targets of the image seeker, this paper combines the advantages of reliable and stable control of “people in the loop” in manual tracking mode, and the advantages of automated information processing and simple shooter operation in automatic tracking mode, and innovatively proposes an anti-interference stable tracking fusion design method for image seeker. In the automatic tracking mode of seeker, when occasional abnormalities such as target tracking failure or target loss occur, the tracking point is slightly corrected through manual adjustment, which not only reduces the operation pressure of the shooter, but also maximizes the reliability and anti-interference ability of automatic tracking under complex backgrounds, bad weather and other conditions. At the same time, based on the principles of intervention continuity, correction agility and automatic tracking stationary, the optimal solution for micro-revision interval time and correction cycle is designed using the analytic hierarchy process method. The semi-physical simulation results show that the micro-repair preferred solution can achieve a missile hit rate of 99% under different simulation conditions.

Image semantic segmentation assigns labels to each pixel in the target category based on the “semantics” of the image scene, distinguishing different types of things in the image. Existing semantic segmentation methods based on DeepLabV3+ have high computational complexity and large memory consumption, and it is difficult to fully utilize multi-scale information when extracting image feature information, which may lead to the loss of detailed information and reduce segmentation accuracy. The outdoor environment has a variety of targets, large changes in lighting conditions, and obstructions, which increase the difficulty of scene understanding and object recognition. Therefore, an improved DeepLabV3+ network outdoor multi-target scene segmentation method is proposed, with the improved MobileNetv2 as the model backbone. The ECAnet channel attention mechanism is applied to low-level features to reduce computational complexity and improve target boundary clarity. After the ASPP module, a polarized self-attention mechanism is introduced to improve the spatial feature representation of the feature mPA. The improved model has an average intersection to union ratio (mIoU) and average accuracy (mPA) of 69.5% and 82.35% on the outdoor dataset Standford BackgroundDataset, respectively. Compared with the original DeepLabV3+model, it has improved by 5.2% and 4.5%. The addition of new modules has no significant impact on the running time, effectively improving the inference efficiency and accuracy of the model.

In modern warfare, the damage efficacy of high-speed penetration weapons against high-strength targets such as underground bunkers and reinforced structures has become a focal point of research. This paper systematically reviews the research progress on the dynamic behavior of projectile materials, constitutive models, and structural responses under high-speed penetration. It analyzes the mechanisms of strain hardening, thermal softening, and adiabatic shear deformation under the coupled effects of high temperature and high strain rate, and compares the applicability of typical constitutive models such as the Johnson-Cook model. Key factors influencing mass erosion, critical instability velocity, and structural failure during high-speed penetration are emphasized, along with their underlying mechanisms. Additionally, technical approaches to enhance penetration capabilities through material optimization and structural design are explored, providing valuable references for researchers in related fields.

In order to study the effect of heat insulation coating structure on the thermal protection performance of fuzes in different thermal environments,the typical large-caliber grenade fuze of JHX-1 charge was taken as the research object,and the slow burning and fast burning simulation of fuzes with no heat insulation coating structure,single heat insulation coating structure and composite heat insulation coating structure were carried out.The simulation results show that the design of the thermal insulation coating structure can prolong the response time of the fuze under both fast and slow burning conditions,and the delay effect is the most obvious in the fast burning environment,the delay effect is 69.1%.Under the same thermal environment and the same thickness of the overall thermal insulation coating of the fuze,the delay effect of the single-coating thermal insulation structure on the response time is better than that of the composite coating thermal insulation structure,and the thermal protection performance is the best when the shell is coated with flame retardant thermal insulation material,and the delay effect is 51.6% under the fast burning ring.According to the comprehensive analysis,the inner/outer composite thermal insulation coating structure can be considered for the fuze body with limited coating thickness,and the thermal protection effect of the composite coating structure can be improved by increasing the coating thickness of the outer material on the basis of meeting the functional requirements of the fuze.

Considering the coexistence of both matched and unmatched unknown disturbances in electro-hydraulic valve-controlled erection systems and the inherent dead-zone nonlinearity in hydraulic valves, a novel nonlinear controller is proposed. First, a nonlinear mathematical model of the electro-hydraulic erection system is established based on the electromechanical-hydraulic coupled dynamics of the system and the dead-zone characteristics of the hydraulic valve. Second, based on the full-state feedback condition, the aforementioned mathematical model is reformulated, and an adaptive extended state observer (AESO) along with a disturbance observer (DO) is designed to estimate both matched and unmatched disturbances, and effectively suppress the observation peaking phenomenon. Third, a novel active disturbance rejection controller is developed leveraging the aforementioned AESO and DO to achieve feedforward compensation for disturbances. Simultaneously, to address the inherent "differential explosion" issue in the conventional backstepping-based controller design framework, a nonlinear command filter is incorporated. At last, through rigorous analysis based on Lyapunov's theory, it demonstrates the boundedness of the motion errors of the system, observer estimation errors and filter error, and verifies the stability of the controller. A simulation platform is developed to validate the performance of the proposed controller. Comparative results with conventional industrial PID controller demonstrate that the proposed controller significantly enhances motion tracking accuracy of the electro-hydraulic erection system.

In order to study the spinning projectile stability of coning motion,provide the dynamic equation around the center of mass in quasi-body coordinate system and establish the short period dynamic model.Derive the equations of coning motion represented by Euler angles.Obtain the analytical solution by introducing complex angle of attack.Analyze the stability of coning motion with initial disturbance in two cases:One situation is ignoring the Magnus effect and damping effect,only analyze the coning motion influenced by the gyroscope effect and the aerodynamic static moment.Another situation is the coning motion adding in the Magnus effect and damping effect,analyze the stabilization and provide the conditions for coning stability.Finally,summarize the influence of rotating speed and statically stability acting on the dynamic stability of coning motion based on theoretical analysis and simulation results:For the low-speed rotating missiles,only under the influence of gyroscopic effect and aerodynamic static moment,a statically stable aerodynamic shape is necessary to achieve coning stability.Statically unstable missiles can only achieve dynamic stability by significantly increasing the rotating speed.Considering the Magnus effect and damping effect,the convergent coning motion of the statically stable missiles with low rotating speed is the easiest to achieve.The divergence of coning motion may occur result in the increasing of rotating speed.For the statically unstable missiles,it is necessary to select the moment of inertia reasonably and increase the rotating speed to achieve dynamic stability.

To improve the resistance of B₄C/Al composite targets against explosively-formed projectile (EFP) penetration, the surface morphology of ceramic strike face is modified. Seven types of B₄C/Al composite targets featuring different protrusion-array structures on the strike face are examined. The processes of EFPs penetrating into the composite targets at 1.5, 1.7, and 1.9 km/s are simulated using LS-DYNA. The evolutions of the projectile's mass, velocity and kinetic energy during penetration are analyzed. The results indicate that B₄C/Al composite targets with protruded strike-face structures exhibit superior penetration resistance and deceleration capability compared with B₄C/Al flat-faced targets. Among them, the composite target with a pyramidal protrusion array provides the best deceleration performance for the simulated EFP.The R3 semi-cylindrical target demonstrates the best protective performance under normal impact. The penetration direction significantly affects the penetration resistance of anisotropic protrusion-array targets and the sinusoidal-structured target has the optimal protection performance under oblique impact.

It is an important direction for the future development of UAV military field to coordinated attack of multi-UAV to accomplish specific strike tasks. Aiming at the problem of coordinated attack of multi-UAV, a typical confrontation scenario is constructed. The unmanned aerial vehicle cooperative attack problem is modeled as a decentralized partially observable Markov decision process (Dec-POMDP), and a unique reward function is designed. The multi-agent deep deterministic policy gradient (MADDPG) algorithm is used to train the attack strategy. Monte Carlo method is used to analyze the simulation experiment, and the results show that after the training of the multi-agent reinforcement learning algorithm, the completion rate of the UAV cooperative attack task reaches 82.9% in specific confrontation scenarios.

In recent years, the development of large-scale low-earth-orbit (LEO) satellite constellations has been progressing at an unprecedented pace, and their potential applications in the military domain have become increasingly prominent. These constellations possess unique technical characteristics that enable them to restructure the traditional kill chain, effectively addressing core challenges such as reconnaissance delays and insufficient cross-domain coordination in precision strikes. This paper provides a comprehensive introduction to the development of large-scale LEO satellite constellations and delves into their application directions in the military field. By examining typical combat scenarios from the perspectives of the kill chain and kill web, this paper analyzes how large-scale LEO satellite constellations can enhance the construction of the kill web and facilitate the closure of the kill chain in the field of precision strike. The findings of this study offer valuable insights and references for the construction of a global and systematic kill web based on a large-scale low-Earth-orbit constellation. Moreover, this research holds significant reference value for the development of China’s anti-access/area denial (A2/AD) strategic system architecture. As related projects in our country continue to advance steadily, the exploration of the potential of large-scale LEO satellite constellations in enhancing military capabilities becomes even more crucial.

In order to support the selection of materials for the combustion chamber shell of solid rocket motor, an evaluation model for the effective volume, mass, mass ratio, and PV/W coefficient of the cylinder section is established based on thickness. Based on 30CrSiNiMoVA, the variation of the structural characteristics of the cylindrical shell under typical metal and non-metallic material conditions could be obtained through non quantitative derivation analysis and a fast lateral analogy method for the comprehensive benefits of typical material shells is proposed. The results indicate that when calculating various structural features, both metallic and non-metallic materials can be equivalent to the same structural form calculation formula. With the increase of pressure, the change of effective volume and mass ratio of cylinder section caused by material replacement is larger and linear,but it has little effect on the change of mass and volumetric efficiency coefficient of cylinder section; Without considering the material craftsmanship and comparing with metal materials,the use of titanium alloy and fiber materials has advantages in improving the comprehensive performance of the shell,and the advantages of fiber materials are more obvious. When using conventional aluminum alloys, it does not have advantages.

Random vibration screening test is essential for the development of on-missile electronics used in steering gear control drivers, whether the structure of the vibration test fixture is reasonable plays an important role in the accuracy and reliability of the test. To combat some problems such as excessive mass, poor vibration transmission characteristics and so on existing in this kind of vibration test fixture, a method of optimization design by comprehensively using topological optimization, parameter optimization combined with pre-stress modal analysis and frequency response analysis is proposed. Taking a typical vibration test fixture as an example, the basic shape of fixture structure is obtained by topological optimization, and the interface location between the fixture and the vibration table is adjusted by parameter optimization according to the actual working conditions and design principles. While the mass of the optimized fixture is reduced by 32.65%, the natural frequency and the quality factor of the response point did not deteriorate significantly and the vibration transmission characteristics meet the design requirements. Through the physical random tests, the power spectral density response curve of the test point is basically consistent with the acceleration amplitude-frequency curve of the simulation response point, which proves the accuracy of the finite element model and the effectiveness of the comprehensive optimization design, and provides references for the subsequent design of the vibration test fixture for missile-borne electronics.

To address the issue of poor impact accuracy in elevated firing operations of helicopter-mounted aerial rockets, an improved method for elevated firing has been proposed through analyzing the combat mechanisms involved. A simulation model for the ballistic trajectory and the damage effectiveness has been established based on the publicly available parameters of a certain armed helicopter and its aerial rockets from abroad. Typical conditions of elevated and level flight firings are selected for comparative analysis of range, dispersion, and damage effectiveness. The simulation results indicate that the improved aerial rockets, when fired in an elevated position, can achieve an attack distance of up to 9 km, while also exhibiting a trend of reduced longitudinal dispersion. The effective damage area of the rocket salvo is 3 times that under level flight conditions. The improved elevated firing method and the suggestions for the fire control and the aiming stabilization optimization mentioned in this paper have certain guiding significance for the application of helicopter elevated firing operations.

A two-stage cooperative trajectory fast planning method based on pseudo-spectral method and sequence convex optimization is proposed for the cooperative guidance problem of hypersonic gliding vehicle. First, a hypersonic gliding vehicle dynamics and kinematics model is established. Secondly, considering multiple path constraints and terminal constraints in the re-entry gliding section, the pseudo-spectral method is used to solve the complex kinematic model of the vehicle offline, and trajectories that satisfy the relevant cooperative indexes are obtained. Then, on the basis of the offline optimized trajectories, an improved sequential convex optimization algorithm is adopted to adaptively update the radius of the trust region, which improves the convergence speed of the algorithm and realizes the rapid planning of the synergistic trajectories under the premise of guaranteeing the accuracy of the solution. Finally, the proposed method is verified by mathematical simulation, and the results show that the method can realize cooperative flight under the state of uncertainty of the initial conditions and model of the vehicle, and the time cooperative error is less than 0.5 s, and the average CPU time of a single trajectory optimization is 3.67 s, which has a good potential for engineering application.

As unmanned combat systems have increasingly emerged as a critical asymmetric warfare approach in naval operations, small unmanned surface vehicles (USVs) have become focal points of international military competition.While leading military powers are actively developing and equipping USVs while advancing countermeasure technologies, significant challenges remain. This study adopts the offensive-defensive dynamics of USVs as its analytical framework, examines the evolving nature of naval warfare in contemporary conflicts, and systematically analyzes the technical specifications, operational tactics, and defensive countermeasures associated with advanced small USVs deployed internationally.Building upon the concept of the USV closed-loop kill chain, we proposes an integrated anti-USV defense architecture that synergistically combines radar surveillance, electronic warfare (reconnaissance/jamming), infrared/electro-optical detection, multi-domain interception systems (air-to-surface/underwater), and asymmetric countermeasures. The findings establish a theoretical foundation for advancing USV-related technologies while providing actionable insights for the development and tactical deployment of next-generation counter-USV systems.

The direction-finding performance of guidance and direction-finding system is limited with a small-aperture array and the array configuration optimization is a key step to improve system performance due to platform resource constraints such as weight,volume,and deployment space.In this paper,the Cramér-Rao bounds (CRBs) for wideband two-dimensional direction-of-arrival (DOA) estimation of both scalar arrays and polarization-sensitive arrays are derived,and a CRB-based performance evaluation and configuration optimization method for small-aperture arrays is proposed.Firstly,the development of wideband DOA estimation and the typical two-dimensional array structures are reviewed,and the wideband signal models based on subband decomposition are established for both scalar arrays and polarization-sensitive arrays.For scalar arrays,a closed-form expression for the CRB of wideband two-dimensional DOA estimation is provided.Subsequently,a general framework and closed-form expression for the CRB of wideband two-dimensional DOA estimation of polarization-sensitive arrays are derived,and a performance evaluation criterion for two-dimensional direction finding with such arrays is established.Finally,A two-dimensional array configuration optimization method based on the derived CRB is proposed by considering the constraints ofguidance system platform on the number of array elements and array aperture.The quantitative optimization of array layout can be achieved by constructing an array configuration optimization set and conducting theoretical performance evaluation.The research results provide theoretical support and technical guidance for the array configuration design and performance evaluation of small-aperture guidance direction-finding systems.

In traditional chined waverider design, the adjustment of design profile parameters is complex and the design intuitiveness is insufficient. To address these issues, this paper proposes a chined upper surface design method based on B-spline curves. The design flexibility and convenience are improved by directly adjusting the design profile through control points. The base profile is constructed by means of Bezier curves, the leading edge and lower surface base profile are determined using the osculating cone theory, and the upper surface profile is designed using cubic and quadratic B-spline curves. The reliability of the proposed method is verified by computational fluid dynamics (CFD) methods, and the aerodynamic performance of the chined waverider is analyzed. The results demonstrate that, as the angle of attack gradually increases, the influence of the chined upper surface on aerodynamic characteristics weakens gradually, and the maximum lift-to-drag ratio appears at the angle of attack ranging from 4° to 6°. The proposed method provides a more intuitive profile optimization means for waverider design, which has reference value for engineering design.

Aiming at the path planning problem of UAVs in complex scenes,this paper proposes a coupling algorithm that uses the improved A-star algorithm and the improved dynamic window method for path planning,so that the UAV has the ability to avoid static and dynamic obstacles.In terms of global planning,by improving the evaluation function of the A^* algorithm,a path planning algorithm that does not rely on the obstacle expansion map is proposed,so that the UAV can plan a safe path against a priori static obstacles.In terms of local planning,an evaluation function for handling dynamic obstacles is added,so that the UAV has good obstacle avoidance capabilities when facing high-speed dynamic obstacles.Aiming at the problem of too many inflection points on the path resulting in frequent acceleration and deceleration after improving the global planning algorithm,a redundant inflection point deletion strategy was proposed.The simulation results show that compared with the traditional algorithm,the improved algorithm has better obstacle avoidance ability and shorter driving trajectory,which verifies the practicability of the algorithm.