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 response to the application requirements of inertial navigation systems for quartz flexible accelerometers with a large range and high dynamic flight accuracy, a new structure for the pendulum assembly of quartz flexible accelerometer is proposed to enhance the range and second-order coefficient of accelerometer. A mathematical model of the designed pendulum assembly is established to derive the scale factor of the designed accelerometer. The design range of accelerometer is theoretically calculated based on the load capacity of servo circuit. The optimization method for the second-order coefficient of the accelerometer is analyzed, and an optimization scheme for the second-order coefficient is provided. Through numerical simulations, it is verified that the deflection and stress of the designed pendulum assembly under full-scale conditions meet the design requirements. Experimental results show that the quartz flexible accelerometer achieves a range of 110g and a second-order coefficient better than 5 μg/g², thereby improving the dynamic application capability of quartz flexible accelerometers in inertial navigation systems.

Hypersonic missiles,unmanned combat aerial vehicles,and other highly maneuverable targets possess maneuverability comparable to that of interceptors,where the interceptor's maneuverability does not exceed 1.2 times that of the target.The terminal acceleration is easily saturated when applying the traditional guidance laws,leading to a significant degradation in interception accuracy.To address this issue,this paper proposes an optimal guidance law for intercepting maneuvering targets with equilibrium maneuverability.By introducing a relative reference frame,an optimal equilibrium compensation strategy that accounts for target maneuvering with dynamic delays is proposed.This strategy overcomes the under-compensation or over-compensation limitations of conventional guidance laws,which rely on presupposed target maneuver pattern.Based on this strategy,terminal constraints for equilibrium interception are formulated,and a two-stage optimal integrated guidance and control method is derived using kinematics in the relative reference frame.In the first stage,the guidance law is designed based on a minimum-distance performance index to rapidly eliminate pointing errors and converge to the equilibrium interception constraint.In the second stage,a quadratic optimal performance index of acceleration is adopted to deal with the effects of target maneuver and inner-loop delay with minimum required acceleration,thereby achieving terminal equilibrium interception of highly maneuverable targets.Comparative simulation results demonstrate that the proposed guidance law significantly reduces the required interception acceleration and improves terminal guidance accuracy compared to existing optimal guidance methods.

This paper investigates the guidance of missiles striking the maneuvering targets in three-dimensional (3D) space in the presence of model uncertainties, unknown target maneuvers and terminal impact angle constraints. An impact angle control guidance law based on nonsingular fixed-time sliding mode control (NFTSMC) and fuzzy logic is proposed. First, a 3D missile-target relative motion model is established, and the terminal impact angle constraint control is reformulated as a line-of-sight (LOS) angle tracking problem. To overcome the singularity commonly encountered in conventional terminal sliding mode control, a nonsingular fixed-time sliding mode surface (NFTSMS) is constructed, and an auxiliary function is introduced to guarantee singularity-free controller design. In addition, a fuzzy logic system (FLS) is incorporated to online approximate the lumped disturbances induced by target maneuvers and model uncertainties. The fixed-time stability of all signals from the closed-loop system is strictly proved based on Lyapunov stability theory. The simulated results show that the proposed guidance law can achieve the accurate interception of maneuvering targets under different initial conditions. Compared with the existing fixed-time sliding mode guidance strategy, it has significant advantages in suppressing the control command chattering and improving the line-of-sight angle tracking accuracy.

In counter-unmanned aerial vehicle （UAV） swarm operations，the attack intent recognition（AIR），as the core preceding link in the decision-making chain，directly determines the effectiveness of counter-UAV resource allocation and countermeasure formulation.In response to the problems of existing intention recognition methods，such as difficult modeling，sensitivity to noise，and poor adaptability to non-attack scenarios，an attack intent recognition method based on long short-term memory （LSTM） and interacting multiple model （IMM） is proposed.The multi-classification problem is transformed into a binary classification task through scenario decoupling，and LSTM is used to extract the temporal motion features.The likelihood value of attack intent is calculated based on the additivity of mutually exclusive event probabilities，and the smooth update and normalization of intent probability are realized combined with the IMM mechanism.Multi-scenario simulations and Monte Carlo experiments show that the proposed method improves the recognition accuracy by more than 10% and shortens the convergence time by more than 2s compared with the traditional UKF-IMM method.It can effectively adapt to complex scenarios such as intent switching and non-attack maneuvers，and has stronger noise robustness，providing accurate intent support for air defense decision-making.

As cislunar space missions transition from exploration to long-term habitation and resource development,there is an escalating demand for positioning,navigation and timing (PNT) technologies characterized by superior autonomy,high precision and robustness.To address the fragmented technologies and insufficient resilience in current systems,this paper first identifies four core challenges for cislunar space PNT:the uneven distribution of ground-based tracking,telemetry,and command (TT&C) infrastructure,the poor geometry and severe signal attenuation of GNSS space service volume (SSV),the low accuracy of celestial navigation,and the lack of a mature cislunar navigation constellation.A holistic intelligent PNT technical framework is constructed from three critical dimensions:(1) intelligent navigation perception and multi-source data fusion,(2) adaptive decision-making with fault tolerance,and (3) resilient earth-moon collaborative architecture.Furthermore,the core implementation paths and coupling mechanisms are clarified.The developement trends,including multimodal large models and edge computing,are also discusses,and the strategic recommendations for future development are proposed.Results demonstrate that this integrated architecture can provide mission-critical support for China’s next-generation comprehensive PNT systems,specifically catering to the high-reliability requirements of establishing a lunar research station and conducting the manned lunar landings.

For the flight control of quadrotor unmanned aerial vehicles (UAVs) affected by multi-source disturbance,a self-tuning sliding mode flight control algorithm based on multi-source disturbance compensation and hierarchical sliding mode control is proposed.The quadrotor UAV system is divided into a two-degrees-of-freedom dual-input fully-actuated subsystem and a four-degrees-of-freedom dual-input underactuated subsystem,based on which the sliding variable of the fully-actuated subsystem is defined.A sliding variable construction method for hierarchical sliding mode controller is proposed,and the sliding variable of the underactuated subsystem is designed by adopting this method.A generalized Super-Twisting disturbance approximator is designed to observe the multi-source disturbance,and a fuzzy compensator is designed to compensate for the approximation error of the disturbance approximator.A reaching gain self-tuning sliding mode controller is designed by utilizing the combined power reaching law,and the disturbance approximator with fuzzy compensator is used to suppress the influence of the multi-source disturbance.The roles of the core modules in the proposed control algorithm are analyzed,and the proposed control algorithm is compared with the existing control algorithms.The comparison results show that the proposed control algorithm has good multi-source disturbance rejection ability,and can also provide superior dynamic control performance.

Fort the tracking control problem of quadrotor unmanned aerial vehicles (UAVs)under the conditions of parameter uncertainties and external interference,an adaptive anti-saturation and anti-singularity appointed-time prescribed performance control method is proposed.Firstly,an adaptive anti-saturation and anti-singularity appointed-time prescribed performance function is designed.The transient and steady-state performance requirements of the system are achieved by selecting the design parameters of this function,ensuring that the tracking errors converge within any appointed time T_ρ.The actuator saturation is effectively avoided by adjusting the design parameter b without additional anti-saturation compensators.Secondly,an adaptive adjustment term is designed to ensure that the tracking errors are always constrained within the preset range,thereby avoiding the singularity problems caused by sudden disturbances in the system.Moreover,the issues of system parameter uncertainties and unknown external disturbances ingeniously resolved using the adaptive method.Subsequently,an event-triggered control mechanism is proposed to reduce the communication and computation burdens and decrease the system energy consumption.Finally,the effectiveness of the designed control method is proved based on the Lyapunov stability theory,and the effectiveness and superiority of the proposed control algorithm are verified through simulation.

Fragments,as the primary damage elements of blast-fragmentation warhead,have their damage lethality which is quantitatively evaluated through precise testing of parameters such as fragment velocity,spatial distribution and mass characteristics.This paper systematically reviews the latest advancements in the parameter testing technologies for the fragment fields of blast-fragmentation warheads,focusing on comparative analysis under two typical conditions of static and dynamic detonations.In the context of static detonation testing,the principles and features of the contact-type technologies such as net targets,the sectional optoelectronic technologies of light curtains and radar and the 3D reconstruction technologies like high-speed stereovision are compared in detail,and their technological improvements and development trends are elaborated.In the context of dynamic detonation testing,the research achievements in testing methods and simulation modeling at home and abroad are reviewed,and the unique challenges such as detonation point control and spatiotemporal synchronizationunder dynamic detonation conditions as well as the corresponding solutions are thoroughly analyzed.Furthermore,this paper also explores the applications and enabling potential of intelligent algorithms represented by machine learning (particularly deep learning) in the aspects fragment target recognition,trajectory tracking,data fusion,and dynamic explosion parameter prediction.Finally,it offers prospects for the future development trends in fragment field parameter testing technologies,and proposes the need to prioritize high-precision dynamic detonation fragment parameter testing technologies,enhance the 3D reconstruction capabilities and strengthen the integration of machine learning in testing methodologies,thereby supporting the optimized design and damage effectiveness evaluation of blast-fragmentation warheads.

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.

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.

The mechanical properties of high-entropy alloys (HEAs) are studied. For this purpose, a simple and precise testing system is established for determining the equation-of-state parameters of HEAs. Based on the principle of wave impedance matching, a test setup is designed using the pressure comparison method to obtain the shock adiabat data of HEA materials. The acquired experimental data is then optimized through adaptive clustering detection. After optimization, the confidence intervals for the slope and intercept of the experimentally determined shock adiabat are narrowed from [1.66293, 2.03332] and [4.01158, 4.38089] to [1.6461, 1.92734] and [4.15248, 4.27542], respectively, and the coefficient of determination (R²) is improved from 0.9687 to 0.9849. The Hugoniot equation-of-state parameters for the HEA are determined as C₂=4.214km/s and λ₂=1.787.The Hugoniot equation of state established in this study is applicable within a pressure range of approximately 5.86-32.77 GPa, and its extrapolation to higher pressure regimes necessitates further experimental validation to guarantee reliability. The results demonstrate that the proposed system achieves high-precision measurement of equation-of-state parameters for high-entropy alloys hrough the combination of data optimization algorithms with experimental design. This work provides critical technical support for the performance assessment and practical application of such materials under dynamic mechanical conditions.

To address the issue of small penetration aperture in traditional shaped charge warheads against underwater single-layer targets,a novel W-shaped shaped charge structure design method based on the inner cone angle α and outer cone angle β is proposed.The influence of liner structure on jet formation and damage effectiveness is studied.The ratio μ of the lengths of the inner and outer sides of the liner is defined a-s a characterization parameter affecting the underwater formation and damage performance of the W-shaped liner.The influence of the ratio μ on the formation and initiation points on the formation and penetration of annular jet are analyzed through numerical simulations.The results indicate that,the annular jet converges excessively toward the axis when μ is 0.22,forming an explosively formed projectile (EFP).When 0<μ<1,the outward expansion trend of the annular jet gradually intensifies,the head-to-tail velocity difference decreases,and the jet stability improves with the increase in μ.When μ>1,the slug at the jet tail is reduced,the jet head expands,the head-to-tail velocity difference increases,and the jet stability significantly decreases under the influence of the external water medium with the increase in μ.Additionally,the increase in the number of initiation points induces necking at the head of the annular jet,which has little impact on penetration and aperture formation under the condition of small standoff distance.The large-area damage of annular jet to the target plate can be achieved by optimizing the combination of the inner and outer cone angles of the liner to adjust the value of μ and the number of initiation points.

The penetration tests on three sets of geometrically similar projectiles with scaling ratios of 1/1, 1/2 and 1/3 are carried out to investigate the size effect of penetration depth of projectile into concrete media. A calculation method for penetration depth with the projectile diameter coefficient as a variable is proposed, and a conversion coefficient model that takes into account the scaling ratio is established for penetration depth. The dynamic strain rate of material in the projectile-target contact zone during the penetration processare quantitatively analyzed through numerical simulation, and the values of penetration depth conversion coefficients under different scaling ratios are ultimately determined. The results show that the size effect exists in the dimensionless penetration depth between the prototype projectile and the model projectile, which arises from the difference in the average strain rates of target in the tests with different scaling ratios. The strain rate increases with the increase of penetration velocity and the decrease of projectile diameter, and does not conform to the geometric similarity scaling relationship. The established penetration depth conversion coefficient is correlated with the target strain rate and the scaling ratio. This conversion coefficient not only quantifies the influence of the material strain rate on the size effect, but also clarifies the mechanism of the size effect of penetration depth in concrete media from a mechanistic perspective.

The influence of grooved structure on the penetration and damage performance of copper-aluminum/polytetrafluoroethylene (Cu-Al/PTFE) energetic composite liner is investigated.A energetic composite liner with large cone angle (140°) is numerically simulated and experimented,and the damage effect of a pre-grooved energetic composite liner on concrete target is examined.A comparison shows good agreement between the experimental and simulated results.The influences of groove structure parameters such as groove width,depth,and wall thickness ratio on the damage effect of jet are further analyzed.The results show that the groovee structure has an effect on the distribution of jet energy between radial expansion and axial penetration.The smaller widths,shallow depths and narrow spacing of grooves are conducive to the radial hole enlargement,whereas the larger widths,greater depths and wider spacing of grooves enhance energy concentration,thereby increasing the penetration depth.Additionally,the number of grooves and the wall thickness ratio significantly influence the stability of jet and the ability of reactive materials to follow up.In particular,a wall thickness ratio of 1∶1 between the copper and reactive material layers yields favourable jet formation and damage performance.

To address the challenge that the frequency-agile radars in the stable tracking phase in modern complex electromagnetic environments struggle have difficulty in balancing both coherent integration gain and anti-jamming capability under blanket jamming,this paper proposes a joint control method for frequency and dwell time based on proximal policy optimization (PPO).Firstly,the trade-off relationship between radar coherent integration gain and intercept risk is analyzed.The dynamic combined jamming behavior of jammers is modeled,and a Markov decision process model for radar anti-jamming,incorporating signal-level feature feedback,is constructed.Secondly,the PPO algorithm is introduced.A compound reward function that takes into account both detection performance and survivability is designed,enabling the radar agent to autonomously learn the optimal strategy in unknown dynamical adversarial environments.This strategy can adjust the operating frequency and dwell time in real-time based on environmental feedback to maximize the signal-to-interference-plus-noise ratio.Simulated results demonstrate that,compared to traditional strategies,the proposed strategy can effectively evade the combined blanket jamming.It significantly reduces the probability of being jammed while substantially improving the output SINR,exhibiting strong environmental adaptability and robustness.

The modal parameters of large-scale missile and rocket systems are generally obtained through finite element analysis and ground vibration tests.Due to the inability to simulate the time-varying characteristics of the system under flight conditions,it is usually necessary to conduct finite element modeling or ground vibration tests based on several characteristic conditions,and finally obtain the flight modal frequency through numerical interpolation.The repeated modeling and ground testing process is time-consuming and laborious.This article presents a fast prediction method for time-varying modal parameters of missile and rocket,which is based on the concentrated mass beam model and finite element method.This method introduces time-varying mass matrix,stiffness matrix,and damping matrix to describe the time-varying system,which can quickly provide the time-varying modal frequency parameters of the system.This method has been validated through ground vibration test and flight test,the results show that this method can reliably simulate the time-varying modal parameters of the system,effectively solving the pain points of the tedious simulation of time-varying systems.Moreover,the time-varying dynamic response data obtained based on this method can be used for dynamic inverse problems such as the modal consistency analysis and load identification.

To address the low decision-making efficiency and poor practicality of weapon-target assignment (WTA) in modern air-defense operations,a multi-objective WTA model that comprehensively considers four performance metrics including ammunition consumption,operational cost,total engagement time,and interception benefit is constructed.Practical constraints such as weapon-ammunition compatibility,ammunition inventory,and damage thresholds,etc,are also taken into account to enhance the battlefield applicability of the model.Secondly,a hybrid heuristic algorithm—hybrid ahaotic quantum particle swarm optimization-variable neighborhood search (HCQPSO-VNS) is proposed to solve the proposed WTA model.In the proposed algorithm,a logistic chaotic mapping is employed to improve the quality of the initial population,the quantum particle swarm optimization (QPSO) is utilized for global search; and the variable neighborhood search (VNS) with multiple neighborhood structures is integrated for local optimization to avoid premature convergence.Simulated results demonstrate that the proposed algorithm converges to a high-quality feasible solution within very few iterations.The obtained assignment schemes satisfy the expected lower bounds for damage,weapon-ammunition compatibility,and other constraints,while achieving an effective balance among four performance metrics.Comparative analysis shows that the overall performance of the proposed algorithm outperforms several mainstream algorithms,and can effectively improve the efficiency and scientific rigor of air-defense firepower allocation decisions.Meanwhile,as the problem complexity increases,the proposed algorithm retains high optimization efficiency and acceptable computational load,demonstrating favorable scalability.

The damage expansion of the interface between the coating sleeve and the propellant in the initial operating section of a fully loaded solid rocket motor is analyzed using the LS-DYNA platform.The numerically simulated results show that the pressure difference between the inner and outer surfaces of the coating sleeve is determined only by the minimum flow cross-sectional area between the coating sleeve and the insulation layer without the consideration of fluid-structure interaction，which is inconsistent with the actual physical process.However，when the fluid-structure interaction is taken into account，the pressure difference between the inner and outer of the coating sleeve first increases and then decreases with the increase of the motor operating time.The pressure difference reaches its peak value of 0.604MPa at 0.4s.The additional stresses might exist at the interface between the coating sleeve and the propellant under the effect of this pressure difference，which could lead to the damage and expansion of the interface.During the design of motor，the gap between the coating sleeve and the insulation layer as well as the elastic modulus of coating sleeve should be comprehensively evaluated to ensure the stable interfacial mechanical properties and slower damage propagation，thereby enhancing the structural stability and reliability.

To further improve the prediction accuracy of solid rocket motor performance a parameter-model coupling-based predictive method for the internal ballistic performance of solid rocket motors is proposed.Firstly,the key factors influencing the prediction deviations are identified by analyzing the discrepancies between the predicted results of the classical zero-dimensional internal ballistic model and the actual motor operations.Secondly,in consideration of the characteristics of these factors,the prediction method is adjusted by using the undetermined parameters and the performance correction models to account for their respective effects.Based on this,a coupled prediction framework integrating both approaches is established.Finally,the internal ballistic performance is predicted and analyzed based on test data by taking the precise performance prediction problems of single-chamber single-thrust and single-chamber dual-thrust solid rocket motors as examples The results indicate that the proposed method significantly enhances the prediction accuracy of macroscopic internal ballistic parameters such as thrust and chamber pressure,while also enabling the precise estimation of mesoscopic parameters including burning surface area,nozzle throat diameter,and propellant burning rate.The prediction deviations for thrust and chamber pressure remain within 1%,and the prediction deviation for mass flow rate remains within 0.1%,thereby supporting comprehensive analysis of the engine's operational process.

Aiming at the problems of insufficient samples， semantic ambiguity and blurred entity boundaries in Chinese named entity recognition for UAV communication， this paper proposes a multifeature fusion Chinese named entity recognition model RCPAC （roberta-wwm-ext-large-CNN-PositionAwareAttention-BiLSTM-CRF）. Firstly， the UAV communication domain dictionary is dynamically integrated into the robertawwmextlarge model to obtain global features fused with domainspecific lexical information. A SqueezeandExcitation Networks （SENet） attention mechanism is introduced into the Convolutional Neural Network （CNN） layer to extraction key feature. Within the bidirectional positionaware attention mechanism， two regiondivided forward and backward attention modules are designed to capture entity boundary features. Then， dynamic weightbased fusion is conducted on the global features with lexical information， multiscale local features extracted by the CNN layer， as well as position information and entity features obtained from the bidirectional positionaware attention mechanism. Next， the Bidirectional Long ShortTerm Memory （BiLSTM） layer is used to model longrange sequence dependencies and filter redundant features. Finally， the Conditional Random Fields （CRF） decoding layer outputs the optimal label sequence. Comparative experiments and ablation experiments verify the effectiveness and superiority of the proposed model. On the selfconstructed smallscale UAV communication dataset， the F1score of the RCPAC model is improved by 1.01%-9.95% compared with other baseline models. In addition， the model achieves F1scores of 92.15% and 95.56% on the CCKS2021 Chinese address element parsing dataset and the MSRA dataset respectively， demonstrating its generalization ability and effectiveness.

It was directed against the power characteristics of high explosive shell of forward enhanced lethal action.On the basis of the shooting line method,a new method for evaluating the damage effectiveness of attacking on vehicles with light thickness armor has been put forward.First of all,the damage levels of vehicles with light thickness armor were clearly separate out.And the criteria for damage caused by fragments to vehicles with light thickness armor was definitely put out.After that,the power characteristics of high explosive shell of forward enhanced lethal action have been thoroughly studied.On the basis of terminal velocity of high explosive shell of forward enhanced lethal action,the theoretical model of ammunition power field has been effectively sit up.On this basis,the process of high explosive shell of forward enhanced lethal action striking vehicles with light thickness armor during the intersection of the projectile and target was carefully researched.Base on the above research results,the damage effectiveness evaluation method based on the shooting line method has been scientifically put forward.In the end,based on the constructed power field theoretical model and damage effectiveness computational method,the destructive efficiency of high explosive shell of forward enhanced lethal action against vehicles with light thickness armor has been carefully calculated.As a result,the technical support for high explosive shell of forward enhanced lethal action attacking on vehicles with light thickness armor has been provided.

A low-sidelobe array pattern design method utilizing fmincon is proposed based on MATLAB.The array beam optimization problem is transformed into a nonlinear constrained optimization problem with continuous variables by constructing a hybrid penalty cost function with the objective of minimizing the sidelobe level in the target region and utilizing the nonlinear constraints for controlling the gain fluctuation of mainlobe.Numerical results demonstrate that The designed array can achieve a suppression of 15-20dB sidelobe level within specified spatial regions while ensuring that the gain fluctuation of mainlobe is less than 0.3dB.And the optimization process exhibits rapid convergence and excellent stability.The proposed method gives consideration to optimization precision and computational efficiency.It provides a high-performance and high-reliability solution for antenna array designs requiring the mainlobe shaping and sidelobe suppression in specific region,has significant engineering practical value.

Under the current conditions of air combat confrontation,targets often behave medium and large overloads and strong maneuvers,and it is difficult to predict the trajectory of maneuver.In order to solve the problems of low prediction accuracy and short prediction time of the traditional trajectory prediction methods,a multi-step trajectory prediction method based on Bayesian optimization hyperparameters in bidirectional long short-term memory network (BO-Bi-LSTM)is proposed in this paper.The sliding prediction method is analyzed,and an online rolling prediction mathematical model is established to solve the problem of prediction value construction.The network hyperparameters are optimized automatically by using Bayesian optimization method,and the optimal hyperparameters are obtained after iteration several times.The length of the sliding window is analyzed,and the length of the sliding window with the highest prediction accuracy is obtained among the classical sliding window length.In order to test the prediction performance of this method on the maneuvering trajectory,a classical maneuvering flight trajectory is predicted and simulated in this paper,and compared with three other neural network prediction models,the simulation results prove that the bidirectional long and short time domain memory network multi-step prediction method with Bayesian optimization hyperparameters is higher in prediction accuracy than the other three neural networks.The accuracy of the 3D trajectory error is less than 200m,which can be predicted continuously for about 4.5s.

The shaped charge is widely used in the field of unexploded ordnance destruction disposal due to its high energy utilization rate.For the safe and effective disposal of unexploded ordnance in water,this paper investigates the factors influencing on the underwater initiation capability of jets.Numerical simulation methods are employed to characterize the jet formation process of two charge structures in water.Focusing on the flared liner shaped charge structure,the effects of the charge structure,the length of the combined cavity structure at the head,and the water depth on the initiation capability of the shaped charge jet are analyzed.The results indicate that the flared liner charge structure affects the jet’s initiation capability in the following order of significance:liner height,liner thickness,explosive column height,and liner curvature.The combined cavity structure significantly reduces the energy loss of the jet by 74.8%.The Random Forest (RF) model effectively predicts the nonlinear variation characteristics of the contact velocity between jet and shelled charges in water with the increase in water depth.

The high-velocity impact of large-mass kinetic energy block is a key technological means of air defense and anti-missile for effectively detonating the internal charges of missile warhead.To improve the interception capability against tactical ballistic missile,reveal the shock initiation laws of cased charges and determine the shock initiation threshold of high-energy explosive charges,the shock initiation effect of kinetic energy block on cased high-energy explosive charges is studied through numerical simulation.Firstly,a cased charge target with HMX and PBX-9404 as fillers is designed based on the existing literatures and target characteristic analysis,of which the impact surface is made of steels with four typical thicknesses ranging from 10 mm to 40 mm.A numerical simulation model for shock initiation effect is established with by seleting the reasonable material parameters.The response of cased charges under high-velocity impact of tungsten alloy block is simulated,and the shock initiation velocity thresholds at impact angles of 0°-80° are obtained.The variation laws of initiation thresholds under different impact angles and shell thicknesses are analyzed,and a threshold calculation model is constructed.Results show that the shock initiation velocity threshold of HMX presents two stages.It remains between 1175m/s and 1525m/s when the impact angle is less than 50° or the shell thickness is less than 30mm; however,as the impact angle or shell thickness further increases,the threshold rises sharply by nearly 300%.The shock initiation velocity threshold of PBX-9404 ranges from 35m/s to 1475m/s and increases with the increment of impact angle and shell thickness.Notably,the growth rate significantly rises to 200% once the impact angle exceeds 50°,which is approximately linearly correlated to the increase in shell thickness.Furthermore,a predictive model for shock initiation velocity threshold is constructed,achieving R² correlation coefficients of 0.93 for HMX and 0.90 for PBX-9404.This research provides support for interception-type anti-missile warhead design.

In modern warfare,reconnaissance and strike integrated unmanned aerial vehicles (RSUAV) face the significant threat of precise strikes from enemy missiles when carrying out tasks such as reconnaissance,surveillance,target location,and precision strikes.To address this challenge,this paper proposes a hybrid dispensing strategy that combines the advantages of chaff and infrared decoys to extend the lifespan of RSUAV in battlefield environments.Specifically,we first construct kinematic models for the RSUAV,chaff decoys,and infrared decoys,and for the first time,integrate a dynamic Radar Cross Section (RCS) model for chaff clouds and a time-varying radiation model for infrared decoys into a unified framework.Subsequently,based on centroid jamming principles,we formulate an objective function for hybrid dispensing decision-making,dynamically adjusting the dispensing strategy by incorporating infrared and radar sensitivity weights to address the challenge of effectively countering composite-guided missiles.Finally,we develop an adaptive genetic algorithm that enhances convergence efficiency by optimizing parameters such as population size and fitness criteria,thereby ensuring real-time responsiveness in complex and dynamic battlefield environments.Simulation experiments show that this method can effectively interfere with enemy missiles,regardless of whether they are infrared,radar,or composite-guided,thereby significantly enhancing the survival capability of RSUAV.This mixed deployment strategy provides more effective electronic warfare means for modern battlefields and holds significant strategic value and application prospects.

Manual assembly of aero-engine casings with dissimilar flanges suffers from low efficiency,poor mating accuracy and high safety risk.To overcome these problems,this paper proposes a compliant control scheme for a six-degree-of-freedom Stewart platform that learns to insert a flange test specimen via reinforcement learning.Firstly,the kinematic and dynamic models of the Stewart platform are established,and its ability to adjust posture under complex constraints is analyzed.Secondly,a data-driven compliant strategy that fuses admittance control with a reinforcement-learning algorithm is designed to realize high-precision mating and gentle insertion.Finally,a co-simulation framework combining Webots and PyCharm is built to verify the effectiveness and robustness of the proposed method under various initial misalignments and disturbances.Results show that,compared with traditional fixed parameter admittance control methods,the proposed method reduces the maximum contact force of the platform by 30.4% and improves the assembly efficiency by about 90% during the assembly process,and achieves a steady-state position error of only 7.5mm.This indicates that the proposed method significantly improves work efficiency and accuracy while ensuring assembly safety,and has good engineering promotion value.

The performance of signal acquisition in satellite navigation receivers is significantly influenced by the setting of detection thresholds.The existing methods are difficult to to adapt to the increasingly complex electromagnetic environments in urban areas,where they are prone to generate false alarms under multiple interference conditions,severely affecting acquisition reliability.To address this issue,a constant false alarm rate (CFAR) detection technique is incorporated into the acquisition of BeiDou B1C signals.An algorithm that dynamically adjusts the decision threshold based on the estimated number of interference targets is proposed.This algorithm adaptively determines the decision threshold of signal acquisition according to the real-time estimated number of interference targets in the environment,thereby enhancing the performance of receiver in multi-interference environment.Simulated results demonstrate that the proposed algorithm significantly improves the robustness and acquisition sensitivity of the receiver in complex interference environments,thereby increasing the operational reliability of military equipment in urban warfare.

To address the challenge of intercepting high-speed maneuvering targets with anti-aircraft missiles,a three-dimensional terminal guidance law that considers the constraints of the terminal line-of-sight angle is proposed.Initially,an adaptive estimation model for target acceleration is established,based on the three-dimensional relative motion model between the missile and its target.This model effectively tracks the line-of-sight angular velocity and achieves high-precision estimation of the target’s maneuver acceleration.Following this,the formula for converting the terminal line-of-sight angle constraints from the ground coordinate to the missile coordinate is derived.Subsequently,a terminal guidance law that is capable of directly utilizing the missile’s seeker measurement information is designed,by integrating sliding mode variable structure control with finite-time convergence theory.It is rigorously proven through mathematical derivations that the proposed guidance law ensures the stability and finite-time convergence of the guidance system’s state variables.Lastly,a digital simulation validation is conducted to evaluate the designed terminal guidance law.The results demonstrate that it not only effectively controls the line-of-sight angle to attain the targeted value but also significantly reduces the missile’s mean miss distance to within 1 meter.Compared to the conventional biased proportional navigation law,it notably decreases the required terminal overload and enhances the missile’s guidance accuracy.Furthermore,by directly incorporating seeker measurement information,the proposed guidance law contributes to simplifying the complexity of the guidance system,offering significant reference and application value for advancing research in air defense missile guidance technology.

To address the threats posed to the unmanned aerial vehicles (UAVs) by flame spread and smoke dispersion in forest fires,this paper proposes a real-time method for generating a regular virtual tube in a dynamic environment with coupled fire and smoke to support safety-critical UAV flight.Firstly,a dynamic environment prediction model is developed based on the wildfire spread dynamics and a smoke advection-diffusion mechanism.A dual-metric mechanism is then proposed to simultaneously characterize the real-time positional risk and spatiotemporal predictive risk,resulting in a unified quantified cost field for both static and dynamic obstacles and a spatiotemporal constraint window.Next,a risk-aware tube-generation framework is built to search a spatiotemporally feasible path by using a risk-aware A* algorithm and generate the regular virtual tube by using an adaptive safe virtual-tube generation algorithm.Simulated results show that the proposed method can regenerate the virtual tube in real time as the fire conditions evolve.Compared with the existing methods,the proposed method increases the minimum safe distance by 43.2%,reduces the maximum cost by 28.7%,and decreases the replanning time by 82.9%,significantly improving both the trajectory safety and flight safety of UAVs in multi-source high-risk environments.

The performance of an electric cruise missile promotion device directly affects its flight speed,range,battery life,and mobility. Therefore,accurately obtaining the performance data of the promotional device plays an important role in the overall design and combat effectiveness evaluation of the cruise missile. Because the propeller of the electric loitering missile is small in size,it is easily affected by the missile body and the coming air. Therefore,the traditional propeller wind tunnel test method is not suitable for the performance test of the propulsion device of the electric loitering missile. This paper took the entire propulsion device of the electric loitering missile as the test object,studied and designed a set of wind tunnel test systems,so as to directly measure and obtain the performance data of the loitering missile propulsion device through the means of wind tunnel tests. The key issues of power supply voltage drop and heating of DC motors were studied. In the end,the wind tunnel test was conducted in the CG-02 low-speed wind tunnel. The results showed that the test system had good accuracy and the test data were closer to the flight test data compared with those of propeller wind tunnel tests. The test system can provide data support for the selection and optimization of the propulsion device of the electric loitering missile,and effectively guide the overall design of the loitering missile.

The overall design of target missiles and their propulsion system design,as sequential steps,require multiple rounds of iterative optimization.Since the propulsion system design adheres to the engine optimization principle,it cannot directly derive optimal overall target missile performance from the input system parameters,leading to extended design cycles and increased costs.Specifically,a solid rocket motor performance analysis model and an external ballistic simulation model for target missiles were developed,achieving single-pass optimization of integrated internal-external ballistic design.A joint design optimization algorithm is established with the objective of maximizing cruise time under constraints including engine structural strength,propellant mechanical properties,overall layout of the missile body,and stability and control characteristics of the target missile.Compared with the initial scheme,the low-altitude supersonic cruise time of the target missile is increased by 27.4%,thereby verifying the rationality of the integrated optimization design scheme for internal and external ballistics.

Rocket sleds are essential for dynamic testing of speed and acceleration in aircraft,missiles,and aerospace vehicles.Finite element analysis (FEA) is a critical component in predicting test conditions for successful rocket sled experiments.As the speed of rocket sled tests increases,the accuracy requirements for FEA models also escalate.Consequently,it is necessary to advance the overall modeling techniques of rocket sleds to meet diverse test requirements.To more accurately predict the dynamic response of rocket sled tests,a high-precision model based on thin-walled structures has been developed.The proposed model employs a shell-solid mixed element approach for precise modeling of thin-walled structures and utilizes displacement coordination methods to ensure displacement consistency between shell and solid elements.This methodology ensures the accurate transfer of loads,thereby enhancing the calculation accuracy and stability of the model.Simulation results of high- and low-speed rocket sled operations indicate that the thin-walled structure of mixed elements outperforms the solid element structure in predicting vibration responses.A comparison between experimental and simulation results shows that,within the study range,the model’s error meets test requirements,and its effectiveness and reliability are validated.Thus,modeling with a mixed element thin-walled structure can more accurately predict the dynamic response of rocket sleds.This approach provides critical technical support for the design and optimization of rocket sled structures and is significantly important in enhancing rocket sled capabilities.

The evaluation of aviation weaponry’s combat capability is not merely a technical matter,but also a strategic one.It directly determines whether the equipment can fulfill its intended operational roles on the battlefield and whether future warfare patterns can be accurately predicted.To address the inherent limitations of traditional evaluation methods—including such as over-reliance on expert experience,insufficient persuasiveness of evaluation models,and difficulties in indicator acquisition,this paper proposes a combat capability evaluation approach for aviation weaponry based on Uncertainty Structural Equation Modeling (USEM).Specifically,Triangular Fuzzy Number (TFN) and Deep Neural Networks (DNN) are both integrated to process collected simulation data,aiming to mitigate the drawbacks of limited data availability and significant subjectivity in expert-derived data,thereby enhancing modeling accuracy.The combat capability indicator values processed via the triangular fuzzy number algorithm are converted into SPSS-compatible files,and imported into AMOS for analysis,enabling the establishment of correlations between the combat capability index values and the structural equation model.The results demonstrate that the CN value ranges from 0 to 3,and the RMSEA value is less than 0.08,The CFI and TLI values are both greater than 0.9,all indicating excellent model fit.Furthermore,the model’s estimated values align with the actual missile combat capability indicators,verifying its validity for evaluating the combat capability of aviation weapons and equipment.

To address the requirements of intercontinental high-speed transportation and global precision strike capabilities,this study innovatively proposes a dual-mode orbital design scheme based on distinct aerospace domain characteristics.For the suborbital vehicle scheme utilizing inertial gliding,a velocity vector resolution method is established through dynamic modeling,combined with Tsiolkovsky’s equation for precise fuel requirement calculation.Regarding the near-space hypersonic flight scheme,a cruise mathematical model is constructed and scramjet engine fuel equations are derived based on lift-to-drag ratio characteristics.Theoretical calculations and numerical simulations reveal that both schemes exhibit significant range-dependent fuel consumption characteristics with a defined technological advantage crossover point:beyond critical range thresholds,orbital vehicles demonstrate substantially lower fuel demands compared to baseline hypersonic solutions.Notably,near-space vehicle performance shows strong coupling with both range and lift-to-drag ratio parameters.Through systematic comparison of technical characteristics between the two orbital schemes,this research provides theoretical foundations and quantitative decision-making support for aerospace transportation vehicle design.

For the requirements of precursor charges in tandem warheads,including large-diameter opening,regular through-hole formation,and stable passage of follow-through projectile,this paper investigates the formation characteristics and penetration performance of a W-truncated annular shaped charge (WTASC).A numerical model is validated against existing experimental results,and the roles of the inner liner region,outer liner region and truncated region in the jet formation and target penetration are analyzed.The results show that the damage effect of the WTASC is jointly governed by the high-velocity jet,the annular penetration band and the mass loading from the truncated region.The penetration process can be divided into four stages:initial crater formation by the jet head,main-body penetration,tail loading,and plug-assisted hole enlargement.Structural parameter analysis indicates that the cone angles mainly affect the energy distribution between axial penetration and radial hole expansion,while the truncation length and outer-liner height mainly influence the jet continuity and plugging behavior.Furthermore,a multi-index evaluation system for penetration capability is established by considering entrance-hole,through-hole,exit-hole and plug characteristics.By introducing an equivalent channel damage index and classifying the penetration capability,this study provides an engineering-oriented evaluation method for the structural optimization of WTASC and the precursor-charge opening design of tandem warhead.

A class of intelligent cooperative differential game guidance problems is investigated for multiple vehicles and manuvering targets.In particular,a leader-follower high-order nonlinear guidance model is established based on the master-slave cooperative guidance structure,and an intelligent cooperative optimal guidance strategy is developed via differential games.An evaluation neural network is established based on the adaptive dynamic programming (ADP) algorithm for self-learning and solving the guidance method online.The stability of the closed-loop system as well as the convergence of evaluation network weights are proved by applying the Lyapunov stability theory and the invariant set principle.Finally,the effectiveness of the method is verified through simulation,where the maximum miss distance and time error of multiple vehicles are less than 0.1m and 0.5s,respectively,demonstrating the accurate cooperative attack on the maneuvering targets.

Hypervelocity guided projectiles are survived the high-g loads within the initial launch and required in-flight alignment after power on,the measurement accuracy of MEMS IMU will decrease after high-g load shocks.In order to solve the problem of low accuracy of in-flight alignment,on the premise of not increasing extra mechanism on the projectile,the idea of rotational modulation is presented to realize the self-compensation of MEMS IMU.The method of improving the accuracy of in-flight alignment through the rotation of the projectile itself in the air is proposed.The roll angle identification algorithm based on the rotational modulation method is derived under the single-axis (roll axis) rotation of the projectile.Based on the established ballistic model,the Monte Carlo simulations are carried out using trajectories with different roll angles,different launching azimuths.The simulation results show that the accuracy of roll angle identification is within 3°.Compared with the traditional roll angle identification method,the accuracy of the rotation modulation method is demonstrated.

To address the difficulty of balancing the operational resources and spatiotemporal constraints in the cooperative interception against high-speed maneuvering targets，this paper proposes a cooperative interception timing optimization method based on an improved SA-ACO algorithm.Firstly，a bilevel programming model for launch scheduling is constructed：the outer layer determines the minimum number of interceptors based on a preset interception probability threshold，while the inner layer cooperatively optimizes the optimal launch time windows for the interceptor missiles.Secondly，to address the difficulty in the continuous-domain optimization of the inner layer，an adaptive simulated annealing-ant colony optimization （SA-ACO） hybrid algorithm is designed as the solver.The shortcomings of traditional algorithms，which are prone to getting stuck in local optima and have slow convergence are overcome by integrating the dynamic hybrid regulation and experience-inspired strategies.Simulations show that the proposed method quickly outputs the optimal combination of minimum interceptor quantity and launch timing while ensuring a high interception probability.It achieves the significant improvements in convergence speed，optimization accuracy and stability，providing an efficient and robust decision-making scheme for multi-missile cooperative scheduling.