Table of Content

30 June 2025, Volume 46 Issue 6

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Research on Blasting Damage Behavior of Reactive Projectile Penetrating into Ceramic Target

LIU Aoxin, ZHANG Jiahao, ZHOU Sheng, LI Peiyu, CHEN Pengwan, LIU Rui, WANG Haifu

2025, 46(6):  240521.  doi:10.12382/bgxb.2024.0521

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The blasting damage mechanism of reactive projectile penetrating into a ceramic target is studied through the ballistic impact experiment. The blasting damage behaviors of reactive projectile penetrating into the ceramic target at different impact velocities and the dispersion characteristics of debris cloud are obtained from the experimen. Based on the one-dimensional stress wave theory and the activation hypothesis of reactive material,the impact initiation behavior of reactive projectile is analyzed. Furthermore,a theoretical model describing the blasting damage behavior of reactive projectile penetrating into the ceramic target is developed by combining the Bernoulli formula. The blasting damage behavior of reactive projectile penetrating into the ceramic target at different velocities are discussed based on experiment and theoretical model. The damage pattern of target,the initiation characteristics of projectile and the dispersion characteristics of debris cloud are analyzed. The results show that the deflagration reaction has a significant effect on the blasting damage behavior of the reactive projectile penetrating into the ceramic target. With the increase of impact velocity,the deflagration reaction of reactive projectile gets more intense,therefore enhancing the damage effect on the target and continuously intensifying the damage degree of ceramic target. The damage pattern of ceramic target evolves from the overall cracking to the global cracking around the central invasion hole,and gradually to the blasting fragmentation. As the impact velocity increases,the mass of the ceramic cone formed by the impact increases continuously. The dispersion velocity of ceramic debris increases first and then decreases. The morphological characteristics of debris cloud behind the target shows a trend of changing from the truncated ellipse to the dart-like shape.

Comparative Study on Predictive Models for Radial Velocities of Fragments after PELE Impacting on Target Plates

WANG Zhanxuan, LI Xintian, XU Lizhi, DU Zhonghua

2025, 46(6):  240533.  doi:10.12382/bgxb.2024.0533

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In order to effectively predict the maximum radial velocity of fragments formecd after a penetrator with enhanced lateral effect (PELE) penetrating a metal target plate,the collision pressure,radial pressure,and fragment stop acceleration time when the PELE impacts the target plate are analyzed through numerical simulation and theoretical analysis method.The results show that the elastic wave theory underestimates the collision pressure when the PELE impacts the target plate,and the calculated results of the shock wave theory are more consistent with the actual situation.The axial pressure is all converted to radial pressure instead of a certain proportion.When the shell reaches the maximum failure strain,it starts to break and stops accelerating,which is more consistent with the actual situation.The radial velocity model is improved based on the above analysis,and compared with the elastic wave model,shock wave model and test results,respectively.When the collision pressure is high,the proposed model is able to effectively predict the maximum radial velocity of fragments after the PELE penetrates into the metal target plate.

Analysis and Compensation of Inertial Navigation External Gimbal Arm Error for the Fuze of Double Spin Ballistic Correction Projectile

WANG Xiaokang, SHEN Qiang, WANG Hanyu, PU Wenyang, YAN Zexu

2025, 46(6):  240514.  doi:10.12382/bgxb.2024.0514

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A double spin ballistic correction projectile exhibits high dynamic characteristics due to aerodynamic changes during controlled flight,resulting in the external gimbal arm errors to exist in the measured data of strapdown inertial navigation system mounted on the spin-isolated portion of the fuze.The measurement of ballistic parameters is affected by the external gimbal arm errors,resulting in a decrease in correction accuracy.To address this issue,this paper models and analyzes the effects of nutation,precession,and high-speed angular motion of double spin ballistic correction projectile on the SINS measured data at the spin-isolated portion of the fuze,thus verifying the relationships among these factors.A compensation method for the external gimbal arm effect error based on gyroscope measurement data is proposed.Simulated results show that,the high dynamic characteristics of double spin ballistic correction projectile with a range of 30km during the controlled flight cause a range error of approximately 57 meters,which is reduced to less than 10 meters after error compensation.Experimental results demonstrate that this compensation method is used to reduce the calculated error of position by around 55%.The proposed compensation method based on gyroscope measurement data effectively reduces the inertial navigation calculation errors caused by the high dynamic characteristics of double spin ballistic correction projectile,thereby significantly improving the precision strike capability of the munition.

Safety Analysis and Equivalent Test Method for Fuzes during Fast Cook-off

LOU Wenzhong, KAN Wenxing, FENG Hengzhen, FAN Chenyang, LU Sining, LU Yi

2025, 46(6):  240463.  doi:10.12382/bgxb.2024.0463

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The thermal protection technology and equivalent testing technology are the key to improving the safety of fuzes during fast cook-off and the iterative efficiency of multiple rounds of optimization design of thermal protection.According to the one-dimensional fuze heat conduction model,the theoretical equations for the radial temperature distributions of explosive and fuze shell are constructed.An aluminum-silicon aerogel thermal protection model is established for aerial bomb fuze.The simulation study on the fast cook-off of fuze is carried out to obtain the temperature change curve of the explosive inside the fuze undergoing a 20-minute heating environment at 800℃.The critical thickness of thermal protection material is 3 mm,and the final temperature of explosive is 87.8℃ lower than its 5 s explosion temperature (280℃),which can ensure the thermal safety of fuze.Taking the fuze coated with aluminum-silicon aerogel as the verification subject,an equivalent test method for the fast cook-off of fuze is established based on simulation analysis and high-temperature flame injection test platformm,which is combined with the standard fast cook-off test method.Test results show that when comparing the temperature measurement data of fuze vulnerable points in standard tests with simulation data,the accuracy of the standard test results exceeds 91%.When comparing the measured temperature of fuze vulnerable points in equivalent tests with the measurement results of standard tests,the accuracy of the equivalent test results exceeds 95%.

Burning Rate Characteristics of Typical DNAN-based Melt-cast Explosives

LI Zhi, DUAN Zhuoping, BAI Zhiling, XU Liji, ZHANG Liansheng, HUANG Fenglei

2025, 46(6):  240565.  doi:10.12382/bgxb.2024.0565

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The reaction evolution model of constrained charge after ignition is the theoretical basis for the design of safe munition release mechanism,and the explosive burning rate-pressure relationship is an important part of the reaction evolution model. To provide a foundation for the design of safety munition reaction violence control for 2,4-dinitroanisole (DNAN)-based melt-cast explosives,an experimental measurement system for closed bomb burning rate-pressure characteristics is established based on the laser ignition technology and the fast-response thermocouple flame front detection technology. The burning rate-pressure relationship of a typical DNAN-based melt-cast explosive RB-2(DNAN/HMX/Al/binder) was obtained through experiment,and the effect of temperature on the burning rate-pressure characteristics of the explosive was investigated. The results show that the burning rate of RB-2 explosives increases and the pressure index increases with the increase in temperature. At the same time,the higher the pressure is,the more significant the effect of temperature on the burning rate is. When RB-2 explosive is subjected to a pressure of 60MPa,its solid structure will fail to result in a rapid increase in the burning rate and shift the combustion mechanism of explosive from the linear conduction combustion to the convective combustion. Compared to melt-cast B explosives,RB-2 explosives exhibit lower burning rates and pressure index,along with higher structural failure pressures of the explosives. The reaction growth after accidental ignition is slower,and the reaction violence is regulated more easily through the reaction release structure.

Overdriven Detonation Test of CL-20-based Aluminized Explosive and Determination of Its Equation of State

LIU Moyan, LIU Yan, BAI Fan, YANG Li, HE Chao, WANG Hongfu, GAO Chenyu, HUANG Fenglei

2025, 46(6):  240382.  doi:10.12382/bgxb.2024.0382

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The overdriven detonation states of high-energy explosives under the conditions of charge structure,different detonation methods and other strong load excitation can improve the explosive energy release ability. The state of ODD products is accurately characterized to address the core problem of the new hexanitrohexaazaisowurtzitane (CL-20)-based aluminized explosives under the action of overdriven detonation (ODD).To this end,the particle velocity of CL-20-based aluminized explosives under ODD conditions is tested based on the impedance matching method,the interfacial pressures of the shock wave in different media are calculated,and the characteristic parameters of detonation reaction zone of CL-20-based aluminized explosives are determined.The parameters of JWL+γ equation of state for the detonation products are calibrated by combining with the real-arithmetic genetic algorithm (RA-GA),and the effects of the equations of state of the different detonation products on the overdriven Hugoniot pressure are revealed.The results show that,when the content of aluminium powder is 0%-30%,the duration of overdriven detonation reaction zone and the width of detonation reaction zone of CL-20-based aluminium-containing explosives are directly proportional to the content of aluminium powder,and the width of the reaction zone is increased by 1.97-2.7 times compared with that of the reaction zone without added aluminium powder,while the efficiency of energy release of detonation reaction zone is inversely proportional to the content of aluminium powder.When the content of aluminum powder is the same,the energy release efficiency of the detonation reaction zone is decreased by 25% after adding AP.Compared with the existing overdriven detonation equation of state,JWL+γ equation of state can better fit the overpressure Hugoniot parameters and the isentropic expansion of C-J state,and the deviation of the calculated pressure results from the experimental results is less than 5.5%,which can provide theoretical support for thoroughly understanding of the dynamic mechanical behaviour of explosive detonation reaction zone.

Effect of Oxygen Content on the Propagation Characteristics of Liquid Kerosene Rotating Detonation Wave in Hollow Combustor

LI Lele, HAN Xinpei, XIAO Qiang, BAI Qiaodong, ZHENG Quan, WENG Chunsheng

2025, 46(6):  240499.  doi:10.12382/bgxb.2024.0499

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The rotating detonation engine,as a highly promising aerospace propulsion system,is currently a research hotspot and frontier in the field of aerospace propulsion.The effect of oxygen content on the propagation characteristics of rotating detonation waves of liquid kerosene in a hollow combustor is investigated experimentally by varying the oxygen content of the oxygen-enriched air and the equivalence ratio.The experiment is conducted based on the research on the annular combustor in Ref.[15].The oxygen content required for the stable propagation of liquid kerosene-oxygen-enriched air rotating detonation wave in the hollow combustor under ambient temperature condition is successfully decreased to 0.28.The rotating detonation wave propagates in single mode under different oxygen contents and equivalence ratios during the experiment.When the equivalence ratio is approximately 1,the average velocity of detonation wave increases with the increase in the oxygen content in the oxygen-enriched air.For the oxygen content of 0.28,the average propagation velocity of rotating detonation wave is 1 742.7m/s.The propagation velocity of detonation wave is lower than the theoretical velocity under the condition of lower oxygen content,while the detonation wave is over-driven under the condition of higher oxygen content (0.34-0.43).The oxygen content has a significant impact on the stability of detonation wave. The stability of detonation wave is poor with an oxygen content of 0.28 when the equivalence ratio increases to 1.31,while the detonation wave still maintains a high level of stability with an oxygen content of 0.38 when the equivalent ratio is 1.35.

Dynamic Response and Energy Dissipation of Foam Aluminum Sandwich Panel Subjected to Underwater Impulsive Loading

WEI Zhenqian, RONG Jili, WEI Huiyang, LI Furong, CHEN Zichao

2025, 46(6):  240539.  doi:10.12382/bgxb.2024.0539

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The dynamic response and energy dissipation mechanism of foam aluminum sandwich panel under underwater impulsive load are analyzed to provide a scientific basis for the protection design of ships and marine engineering structures.The consistency between the test and simulated results is verified through the underwater explosion equivalent impact test and simulation.The influences of structural parameters,such as core layer mass ratio,panel thickness,foam aluminum density and impact load on the impact resistance of sandwich panels are quantified.Multi-objective optimization of sandwich panel structure is carried out using neural network and genetic algorithm.The results show that the foam aluminum sandwich panels subjected to underwater impact loading exhibit the deformation patterns such as local collapse and boundary shear.When the mass of sandwich panel is constant,there exists an optimal core layer mass ratio and an optimal wet panel thickness,which increase with the increase of dimensionless impulse.As the thickness of wet panel and the density of core layer decrease,the energy absorption efficiency of the compression deformation of core layer increases.The optimized sandwich panel has significantly reduced deformation and mass.

Protection Performance of SiC/UHMWPE Bulletproof Insert Plate with Biomimetic Topology Interlocking Configuration-based Ceramic Assembly

QIAN Haocheng, WEN Yaoke, WANG Meng, LUO Xiaohao, WANG Huicheng, NIE Weixiao, FENG Zhiyan, TONG Liangcheng

2025, 46(6):  240457.  doi:10.12382/bgxb.2024.0457

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To address the issues of the lack of structural synergy between ceramic plates in existing spliced ceramic bulletproof plates and the poor dissipation of impact energy,a biomimetic topological interlocking ceramic splicing scheme based on the exoskeletal structure of phloeodes diabolicus is designed.The numerical simulation research is made on the protective performance of the designed bulletproof plates under the impact of bullets. A non-standard bulletproof ceramic plate with a phloeodes diabolicus exoskeletal structure is designed based on the microstructure of biological materials and the principle of topological interlocking in engineering structures.The accuracy of the simulation model is verified through 3D-DIC testing,and the penetrations of 5.8mm DBP 10 rifle bullets into square,hexagonal and biomimetic topological interlocking ceramic spliced bulletproof plates are simulated.The results show that the biomimetic topological interlocking ceramic blocks can effectively enable the surrounding ceramics to dissipate the impact energy,The back bulge height of the biomimetic topological interlocking ceramic bulletproof insert after being penetrated is reduced by approximately 8% compared to that of the hexagonal ceramic bulletproof insert.An individual soldier protective insert plate based on the biomimetic topological interlocking ceramic configuration is designed,and the numerical simulations are conducted on the blunt trauma effects of M80 rifle bullet penetrating the human torso of the protected individual soldier.The results indicate that the blunt trauma energy is primarily borne by the muscles and thoracic ribs,and the peak stress on thoracic ribs reaches 30.7MPa,which potentially leads to bone fractures.The maximum stress in the heart is 930.2kPa,and the maximum stress in the lungs is 777.5kPa,potentially causing myocardial injury and lung soft tissue contusion.

Target Acquisition Probability of an Airborne Strapdown Missile at Hand-over Point

WU Jiayang, YANG Huabo, BAI Xibin, ZHANG Shifeng

2025, 46(6):  240495.  doi:10.12382/bgxb.2024.0495

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The acquisition of a ground-moving target at the terminal guidance hand-over point in the scenario of an airborne strapdown missile attacking the target is investigated.The influences of three key factors,including missile position dispersion,attitude dispersion,and target dispersion,on the acquisition probability of infrared seeker are studied.Then the analytical expression for the mean square error of line-of-sight angle is derived based on functional error analysis.Furthermore,an analytical model of acquisition probability under two attack modes,namely current point and pre-point,is established.Simulated results verify the model’s accuracy,which enables determining the range of moving velocity of target that can be engaged.

Energy Management Strategy Optimized by Munchausen-PER-DDQN for Hybrid Tracked Vehicle

LU Xiaoran, ZOU Yuan, ZHANG Xudong, SUN Wei, MENG Yihao, ZHANG Bin

2025, 46(6):  240498.  doi:10.12382/bgxb.2024.0498

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To optimize the fuel economy of the series hybrid tracked vehicle and reduce the offline training time of neural network,an energy management strategy (EMS) based on double-deep Q_learning network (DDQN) algorithm with Munchausen gradient optimization and prioritized experience replay (Munchausen-PER-DDQN) is proposed.The required power is calculated by a vehicle model which involves the engine-generator set,the battery pack and drive motor,and then the peoposed strategy is used to optimally control the throttle opening of engine based on power demand.The Munchausen gradient optimization algorithm adds log-policy to the reward to ease the learning of sub-optimal actions,and the prioritized experience replay algorithm assigns higher selection possibility to certain experience for those who have more influence on the training of the algorithm,Tthe energy management strategy based on Munchausen-PER-DDQN algorithm shows a better performance of fuel economy and training time of neural network.The simulated result shows that,compared with TD3-PER algorithm,the Munchausen-PER-DDQN algorithm achieves 35.3% improvement in neural network training time and 4.6% improvement in the fuel economy.

Elastic-plastic Contact Calculation and Sealing Performance Analysis of Metal Sealing Ring

WANG Kai, ZHENG Mengwei, GONG Hao, LIU Jianhua, ZHAO Youlei, LIU Shaoli

2025, 46(6):  240371.  doi:10.12382/bgxb.2024.0371

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Metal sealing rings are widely used in various mechanical products,mainly achieving the sealing effect through the elastic-plastic contact deformation of rough surfaces.The traditional finite element simulation method for the microscopic contact of rough surfaces has the low computational efficiency and difficult convergence of elastic-plastic contact deformation.An elastic-plastic contact calculation method based on coupled finite element and boundary element methods is proposed.A macro-finite element model of metal ring seal structure is established to accurately solve the contact stress distribution of sealing surfaces,and the micro-morphology of sealing surfaces is established.A boundary element method for elastic-plastic contact calculation with the superposition of residual deformation and residual stress fields is proposed by taking the macroscopic contact stress distribution as the boundary condition.The boundary element method is used to solve the contact state of sealing surfaces under elastic-plastic deformation.Meanwhile,the micro-contact equivalent modeling method of sealing surfaces is verified,and compared with the finite element simulation method for the microscopic contact of rough surfaces.The results show that the calculational accuracy of the finite element-boundary element coupling simulation method is equivalent to that of the finite element method,but its calculational efficiency is improved by nearly 8 times.The leakage channels of sealing surfaces are solved by the four-connection grid model and used as the evaluation index of sealing performance.The effects of material parameters,contact stress,surface roughness and rough surface parameters on the sealing performance of metal sealing ring are systematically studied.A sealing test equipment is built to measure the leakage rate of metal sealing ring,and the variation law of the actual leakage rates of metal sealing ring with the normal load is obtained.The simulated results are consistent with the experimental trend.

Experimental Study on Acoustic Emission Characteristics of High-cycle Fatigue Cracks in Blades

LIU Qiang, YU Yang, YANG Ping

2025, 46(6):  240537.  doi:10.12382/bgxb.2024.0537

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In view of the problem that there is no effective online monitoring means in the process of blade high-cycle fatigue crack damage,an acoustic emission technology is adopted to study the online monitoring test of blade high-cycle fatigue crack acoustic emission under the action of fixed amplitude load,and explore the evolution law of blade crack initiation and propagation signal characteristics.The acoustic emission parameters and frequency spectrum characteristics of high-cycle fatigue crack are studied,and a crack activity coefficient index (CAI) is proposed.The high-cycle fatigue cracks in blades are divided into three stages,i.e.,crack initiation,metastable propagation,and rapid propagation.At the end of crack initiation and the rapid propagation stage,the crack activity coefficient significantly increases,which can achieve early warning of cracks.The generalized S transform is used to analyze the frequency spectra of acoustic emission signals at different damage stages,The results show that the signal energy is concentrated at 90-160kHz during crack initiation,the signal energy is mainly concentrated at 80-180kHz during the crack propagation,and a distinct energy peak at 120kHz appears during rapid crack propagation,The signal energy is the highest during rapid crack propagation,the energy is higher during crack initiation,and the energy is the lowest during crack metastable propagation.

Effect of Cryogenic Treatment Time on Microstructure and Mechanical Properties of a Low-carbon High-alloy Martensite Steel

HE Jin, YANG Bin, WANG Yingchun, CHI Hongxiao, ZHOU Jian, CHENG Xingwang

2025, 46(6):  240532.  doi:10.12382/bgxb.2024.0532

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To achieve the superior performance of aerospace bearing steel by controlling the retained austenite content,the optimization of cryogenic treatment parameters is an effective approach.The microstructure and mechanical properties of a low-carbon Co-Cr-Mo-Ni-W high-alloy martensite steel after quenching,cryogenic treatment at -75℃ for different times and tempering are investigated.The results show that the microstructure of the martensite steel after cryogenic tempering contains the complex phases with tempered martensite,retained austenite and nano-carbides.As the cryogenic time increases from 2 to 6h,the strength of the steel significantly improves and its ductility reduces due to the refinement of tempered martensite lath and the decrease in residual austenite volume fraction,the increase in dislocation density and the increase in the quantity of nano-carbides with more uniform distribution.When the cryogenic time exceeds 6h,the strength and ductility of the steel change slightly because the retained austenite volume fraction decreases,the dislocation density increases and the nano-carbide sizes coarsen with the decrease in quantity.An excellent balance of strength and ductility,with the mean yield strength of about 1690MPa,the ultimate strength of about 1940MPa and the mean elongation of about 14.3%,is achieved for the steel after quenching,cryogenic treatment for 6-10h and tempering.

YSG-SLAM:a Real-time Semantic RGB-D SLAM Based on YOLACT in Dynamic Scene

ZHAI Weiguang, WANG Feng, MA Xingyu, ZHAO Wei, MENG Pengshuai

2025, 46(6):  240443.  doi:10.12382/bgxb.2024.0443

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Simultaneous localization and mapping (SLAM) algorithm has the issues such as localization drift and poor real-time performance in attitude estimation within dynamic environment.A real-time semantic RGB-D SLAM system named as YSG-SLAM is proposed.To enhance the system’s real-time performance,two parallel threads,one for semantic segmentation to obtain 2D semantic information and another for semantic mapping, are introduced.To improve the accuracy and robustness of the system in handling the dynamic objects,YSG-SLAM incorporates a fast dynamic feature removal algorithm and couples it with a missed detection compensation module to mitigate potential missed detections from YOLACT segmentation algorithm.This effectively enhances the feature point removal accuracy and overall system stability.To reduce the localization errors caused by feature point clustering and optimize the spatial distribution of feature points,an adaptive corner extraction threshold calculation method is designed to make the distribution of features more uniform.The semantic mapping thread makes full use of 2D semantic information and 3D point cloud data to optionally construct semantic maps and octree maps,thereby improving the environmental perception capability of system and the task execution ability of robots in complex environment.YSG-SLAM has been evaluated on TUM and Bonn datasets,showing a 93% reduction in various localization errors compared to the original ORB-SLAM2.Experimental results indicate that YSG-SLAM significantly improves real-time performance,has high localization accuracy,and can construct two types of maps.

Lightweight Transmedia High-speed Small Target Detection Method Based on Coordinate Attention Mechanism

DONG Yi, KONG Xiaofang, LUO Hong’e, WAN Gang, XIA Yan, WAN Minjie

2025, 46(6):  240380.  doi:10.12382/bgxb.2024.0380

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In the field of high-speed projectile testing,the very high speed of projectiles poses a significant challenge to detection techniques,which in turn limits the ability to detect and localize projectiles in real time.Moreover,the available datasets for projectile detection are scarce due to the high cost and the complexity of projectile experimental setup.To address the above problems,a transmedia projectile water-entry test system is constructed.A transmedia projectile dataset is created from the projectile images captured by a high-speed camera, and expanded with data enhancement method.Aiming at the problem that the detection accuracy of projectile water-entry is significantly lower than that of projectile in air and water,a transmedia small target detection method based on a coordinate attention (CA) mechanism is proposed.The proposed method replaces the traditional convolution with depth-separable convolution on the basis of recognizing the projectile small targets with high accuracy,which achieves a good balance among detection accuracy,speed and model complexity.The experimental results show that the proposed method improves the detection accuracy by 2.68% and the recall ratio by 7.31% at the instant of projectile water-entry,which provides a solution for transmedia high-speed small target detection.

Map Lightweight Processing and Staircase Area Classification Method for Indoor Navigation of Unmanned Ground Platforms

MA Yuwei, WU Weichao, WANG Wei, NIU Ailin, GUO Zhiming, YANG Jianxin

2025, 46(6):  240483.  doi:10.12382/bgxb.2024.0483

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Constructing an environment map is a crucial prerequisite for navigation,and a comprehensive and detailed map can effectively assist in planning the optimal motion paths for unmanned ground platforms.To address the issues of data redundancy and difficulty in distinguishing the terrain structures in traditional map construction methods,a lightweight map processing and staircase area classification method for indoor navigation of unmanned ground platforms is proposed.The method first extracts the traversable area for unmanned platforms to reduce data redundancy and removes the outliers based on the distribution characteristics of stair surfaces.Subsequently,a map construction algorithm incorporating edge smoothing is used to generate multi-layer grid maps with clear boundaries,regular shapes,and distinct levels.Then,the stair environment features are extracted,and a Naive Bayes classification algorithm with Laplace smoothing is employed to distinguish and label the structures such as steps and turning platforms.The experimental results show that the maps generated by this method maintain high resolution while reducing the data volume by an order of magnitude compared to traditional point cloud maps,and the macro-precision rate of map classification reaches 91.3%.Compared with conventional methods,the proposed method can construct more lightweight multi-layer grid maps with terrain classification labels,providing safe and efficient navigation support for unmanned ground platforms.

Construction of Special Obstacle Dataset and Detection Algorithm Evaluation System in Air-ground Collaborative Scenarios

LENG Chengyu, ZHAO Jin, LIU Chang, YANG Shifeng

2025, 46(6):  240583.  doi:10.12382/bgxb.2024.0583

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The recognition and handling of special obstacles are critical to ensuring the safe operation of ground equipment in air-ground collaborative scenarios.To address the lack of data samples in unstructured environments,a detection dataset comprising 33124 images is developed,featuring a wide range of typical special obstacles to support the recognition tasks in complex scenes.A comprehensive evaluation index integrating the category information and localization accuracy is designed to enhance the objectivity and reliability of algorithm performance comparisons.Additionally,a passability analysis method is proposed,which combines the physical properties with the environmental semantics to guide path planning for unmanned ground systems.Experimental results demonstrate that the proposed dataset and evaluation framework significantly improve detection accuracy,and the method effectively identifies typical obstacles such as potholes and water surfaces in unstructured environments.

Joint State Equality Constraint Identification and Recursive Filtering Based on Deep Learning

QIN Yuemei, CHEN Zhong, YANG Yanbo, LI Shuying

2025, 46(6):  240578.  doi:10.12382/bgxb.2024.0578

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The state estimation problem of equality constraint-based target tracking where multiple constraints coexist and the current constraint information is unknown is presented.A joint state equality constraint identification and recursive filtering based on deep learning algorithm is proposed.The gated recurrent units are used to construct a constraint discriminant network,and the current state constraint is identified online by using the radar measurement.A filtering gain learning network based on cascaded gated recurrent units is built in the framework of recursive filtering to adaptively estimate the target state with the help of joint probabilistic modeling and data learning.The final high-precision filtered estimate which meets the real state equality constraint at current sampling instant is obtained based on filtering projection,which combines the state estimate obtained by the gain learning network with the state equality constraint identified by the constraint discriminant network.Experimental results of multi-target tracking example demonstrate that the proposed algorithm outperforms Kalman filtering,interacting multiple model (based on different motion modes/different state equality constraints) and KalmanNet algorithm in terms of estimation accuracy and robustness,with different levels of measurement noises.

Special Topics of Academic Papers at the 27th Annual Meeting of the China Association for Science and technology

Thermal-ignition Response of Warhead Charge and Characteristics of Typical Thermal Protection Structure under Hypersonic Aerodynamic Heating

YAN Ming, WANG Xinjie, HUANG Fenglei, YOU Sa

2025, 46(6):  240401.  doi:10.12382/bgxb.2024.0401

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Hypersonic warheads usually induce serious aerodynamic heating during flying,and the warhead charge also bears a harsh thermal environment because of the structural heating which may affect its thermal safety.The finite volume method and the two-way fluid-structure interaction method are used to simulate the aerodynamic heating and structural heat transfer processes of hypersonic warheads.The temperature field distribution of pneumatic heating of hypersonic warhead and the thermal-ignition response of charge at different speeds and angles of attack are analyzed based on the chemical reaction kinetics model of explosive.The results reveale that the highest temperature occurs at the head of the warhead under aerodynamic heating and structural heating transferduring the hypersonic flight of warhead,and then it decreases backwards and inward.The temperature distribution is asymmetrical at different angles of attack,the temperature on the windward side increases with the increase in the angle of attack,and the temperature on the leeward side decreases with the increase of the angle of attack.After introducing the chemical reaction kinetics model,the ignition of the charge appears on its head at 35.4s and 574K.the faster the warhead’s speed is,the more severe the aerodynamic heating it experiences is,and the shorter the ignition time of charge is.A thermal protection structure is designed,which can effectively increase the temperatures of warhead’s shell and charge by 79.12% and 71.45% during its 100s flight process as well as ensure that the internal charge does not ignite.This study is of great significance in addressing the thermal safety issues of hypersonic warhead charges.

Analysis of the Influence of Shock Waves on the Detection Performance of Laser Fuze under High-speed Flight Conditions

ZHA Jipeng, ZHANG Xiangjin, HUA Tuan, SHENG Na, KANG Yang

2025, 46(6):  241131.  doi:10.12382/bgxb.2024.1131

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The impact of shock waves in front of projectile under high-speed flight conditions is studied to improve the ranging accuracy of projectile-borne pulse laser fuze. Based on the traditional pulse laser echo model,a semi-analytical method is proposed to model the pulse laser echo signals disturbed by shock waves,and the concept of the optimal confidence interval is introduced to construct a ranging data distribution and error evaluation model. A Reynolds average navier-stokes (RANS) solver is used for aerodynamic flow field calculation to obtain the density field distribution around the projectile by taking a typical high-explosive anti-tank cartridge as the research object. The optical path difference (OPD) and Strehl ratio (SR) are used as the evaluation criteria for the aerodynamic optical effects,and a high-precision fourth-order Runge-Kutta method is employed to trace the laser beam passing through the non-uniform flow field in front of the projectile. The effects of different flight Mach numbers,target angles,and detection distances on the pulse laser echo waveforms and detection accuracy are analyzed through simulation. The simulated results show that the ranging performance of pulse laser fuzes below 3 Mach is slightly affected,and the systematic error and random error reach the minimum and maximum,respectively,at 4 Mach. This study provides theoretical foundations for suppressing the aerodynamic optical effects of pulse laser fuzes under high-speed flight conditions.

Initiation and Detonation Characteristics of Small-sized HNS Explosive Charges under the Impact of High-speed Flyers Driven by Electric Explosion

YANG Kun, LIU Danyang, JIAN Yutong, WANG Jing, LIU Changhua, HE Yaxin, GU Lingzhi, CHEN Lang

2025, 46(6):  240081.  doi:10.12382/bgxb.2025.0081

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Exploding foil initiators (EFIs) represents a promising initiation technology for meeting the high requirements of miniaturized and integrated weapon systems for initiation capability.To conduct an in-depth research on the initiation and detonation output characteristics of small-sized charges in the exploding foil initiator system,a synchronous test system for observing the electrical explosion-driven flyer characteristics of metal bridge foils and a particle velocity measurement system for measuring the velocity of particle at the explosive-window interface for flyer-impact-initiated small-sized explosive detonation are built.The velocity and morphological characteristics of flyers and the initiation and detonation reaction behaviors of small-sized Ultrafine Hexanitrostilbene (HNS-IV) explosive under flyer impact were investigated.The results show that the flyer velocity is positively correlated with the initiation voltage.When the initiation voltage ranges from 900V to 1500V, the flyer velocity exiting the accelerator chamber is measured at 2000m/s to 4200m/s.HNS-IV-based explosives demonstrates a short growth distance of detonation under high-intensity impact.For instance,a stable detonation is achieved within just 2.14mm under the action of a 3455m/s flyer.The further analysis of detonation wave structure indicates that HNS-IV has a fast detonation reaction rate,with a reaction time of less than 27 ns and a reaction zone width of only 0.13mm.Under the condition of a 3mm-diameter charge,the main detonation reaction of HNS-IV explosives remaines largely unaffected,but the energy decays rapidly in the late stage of reaction.The detonation reaction rate model is first calibrated with the experimental results,and then the effect of charge size on the energy output is studied through simulation.The results show that the increase in charge thickness is more effective in enhancing the energy output at the end of charge than the increase in charge diameter.

Characteristics of Fragment Cloud Produced by Hypervelocity Impact of Cylindrical Projectile on Stiffened Plate

NI Yingfeng, CHEN Xiaowei

2025, 46(6):  240812.  doi:10.12382/bgxb.2024.0812

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Regarding the issue of hypervelocity impact on ship-stiffened plate structures,the research has predominantly focused on the information about residual projectile and the characteristics of target plate breaches,while there has been a lack of research on the formation and distribution of fragment cloud.In this study,the finite element-smoothed particle hydrodynamics (FE-SPH) adaptive method,incorporating the Johnson-Cook failure criteria and the maximum tensile strain failure criteria is used to simulate the formation of the fragment cloud produced by cylinder projectile impacting a stiffened plate.Simulated results indicate that the cylindrical projectile forms a fragment cloud with double-saddle shape due to the influence of stiffeners during the impact process,and the main part of the fragment cloud is concentrated at the front end,including hazardous fragments on the inside and small fragments on the outside.Moreover,the distribution of fragments is consistent with the experimental result.The impact process is divided into three stages based on the cbharacteristics of fragment distribution,and the formation and propagation of fragments at each stage are discussed.The topographic characteristics of fragment cloud under various stiffener configurations are presented by varying the impact location of cylindrical projectile.Finally,the characteristic parameters,such as mass and kinetic energy,of the hazardous fragments in the fragment cloud are studied,and the degrees of influence of different impact locations are discussed,which is used to assess the damage ability of hazardous fragments to the rear plate.The analyzed results show that the fragments concentrate towards specific areas to form double-saddle shape and saddle shape due to the influence of the stiffeners.The generation of hazardous fragments is primarily influenced by the main stiffener.

A Prediction Model for Dynamic Penetration of Shaped Charge Jet

WANG Yizhen, YIN Jianping, ZHANG Xuepeng, YI Jianya, LI Xudong

2025, 46(6):  240932.  doi:10.12382/bgxb.2024.0932

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In order to study the variation law of the penetration power of shaped charge jet under lateral disturbance,the finite element models of the dynamic penetration of shaped charge jet are established,and the evolutionary process of jet penetration from static to dynamic conditions is analyzed.Based on the virtual origin theory and dimensional analysis method,a virtual source is introduced to characterize the jet in the dimensional analytical model.An engineering prediction model for dynamic jet penetration depth,which considers lateral disturbance,jet and target plate strength,is established.A jet dynamic penetration test based on a rocket sled is designed and conducted,and the numerical simulation and prediction models are validated.The research results indicate that the dynamic penetration depth of shaped charge jet decreases exponentially with the increase in the lateral disturbance of target plates.The numerically simulated results,prediction model,and experimental results are in good agreement with each other,and both the prediction model and numerical simulation have a certain degree of accuracy and effectiveness.The proposed prediction model can describe the influence of lateral disturbance on the penetration power of shaped charge jet,thus providing a basis and reference for evaluating the dynamic damage power of formed charges.

Calculation of Impact Energy Release Based on Fragment Size Distribution for Reactive Materials

ZHOU Jie, ZHAO Xufeng, PI Aiguo

2025, 46(6):  240545.  doi:10.12382/bgxb.2024.0545

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Aiming at the dynamic fragmentation characteristics of reactive material and its effect on the impact energy release behavior,two types of reactive materials,Al/Ti and Al/Ti/W,are selected as the research subjects.Dynamic fragment soft-recovery test is conducted to obtain the fragment size distribution characteristics of reactive material at different impact velocities.Additionally,the impact-induced energy release test is performed to analyze the impact pressure characteristics and reaction processes of Al/Ti and Al/Ti/W.Based on these investigations,a calculation method for impact pressure,which considers material fragmentation characteristics and the critical size of the reaction,is proposed.The results indicate that the fragmentation characteristics of reactive material are crucial in influencing its impact energy release behavior.The cumulative size distribution of fine fragments formed after the impact fragmentations of both Al/Ti and Al/Ti/W materials can be described using a Logistic distribution function.The impact reaction process of reactive material in a reaction chamber can be divided into primary and secondary reaction stages.The calculation error of the proposed calculation method is less than 15% when calculating the quasi-static pressure during the primary reaction stage.

Intelligent Hypersonic Gliding Vehicle Trajectory Prediction Based on Aerodynamic Acceleration Estimation

YU Mingjun, ZHANG Jialiang, SHEN Haidong, LIU Yanbin, CHEN Jinbao

2025, 46(6):  240035.  doi:10.12382/bgxb.2025.0035

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The near-space hypersonic gliding vehicle (HGV) poses a significant threat to existing defense systems due to its ultra-high velocity,extreme maneuverability,and superior penetration capabilities.To address the challenges in tracking and predicting HGV trajectories during interception,this paper presents an intelligent trajectory prediction method based on aerodynamic acceleration estimation.The maneuver patterns and aerodynamic variation laws of HGV are systematically analyzed according to the HGV motion model.On this basis,three critical parameters,i.e.,aerodynamic lift acceleration,drag acceleration and bank angle control,are identified as trajectory prediction variables for replacing the unknown terms in the HGV motion model.A dynamics tracking model based on aerodynamic acceleration estimation is developed to use the radar measurement data and the unscented Kalman filter (UKF) for real-time tracking and estimation of these parameters.These estimated parameters are then used as inputs to train a long short-term memory (LSTM) network,which captures the temporal relationships and variation patterns in the prediction parameters.The trained LSTM network is used to iteratively forecasts future aerodynamic accelerations,which are integrated with the numerical solutions of motion equations to extrapolate HGV trajectories.Numerical simulations confirm that the proposed method achieves high prediction accuracy and robust stability in predicting the trajectories of non-cooperative HGVs.

An Energy-optimal Relative-angle-constrained Cooperative Guidance Method Based on Distributed Convex Optimization

WANG Jiang, ZHU Ziyang, LI Hongyan, WANG Peng

2025, 46(6):  240739.  doi:10.12382/bgxb.2024.0739

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The angle-optimal cooperative guidance of multiple aerial vehicles enables multi-directional interception of maneuvering targets with minimal energy consumption,which is an important research direction in the field of guidance.The current optimal cooperative guidance methods depend on global information and centralized communication which has low reliability in practical applications.To address the issue mentioned above,an energy-optimal relative-angle-constrained cooperative guidance method based on distributed convex optimization is proposed to resolve the contradiction between the locality of distributed information and the global optimality of cooperative commands.Based on the generalized trajectory shaping guidance law (GTSG),the mapping relationship between aerial vehicle control energy and desired terminal line-of-sight (LOS) angle is derived.A convex objective function is formulated using total control energy,and the convex constraints are established based on relative LOS angle constraints,thereby constructing a distributed convex optimization problem.The extended primal-dual algorithm (EPDA) is then introduced to achieve distributed global optimization,enabling the real-time coordination of aerial vehicle LOS angles for minimum-energy interception.The simulated results and analysis demonstrate that the proposed method does not rely on a central node while ensuring global energy optimality compared with existing centralized angle-coordinated guidance algorithms.

Modeling and Verification of Dynamic Imaging of UAV-borne Line-array LiDAR

WANG Weihan, GAO Mingze, SHI Xiaolong, HU Shiyuan, WU Yanjiang, CHEN Huimin

2025, 46(6):  240836.  doi:10.12382/bgxb.2024.0836

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A dynamic imaging model for UAV(Unmanned Aerial Vehicle)-borne line-array LiDAR is proposed to address the scarcity of point cloud datasets in UAV imaging scene.A pillar-voxel-based point cloud target detection algorithm is proposed to verify the authenticity of the simulation data.The typical target models and the typical scenarios with rugged terrain,camouflage,and vegetation cover are established based on a virtual simulation platform.A laser point cloud dataset is generated by using the point cloud simulation model,UAV motion model,stitching imaging and distortion correction methods.The dataset is annotated by using a completeness judgment method based on overlapping areas.A pilar-voxel feature extraction module is used to process the target’s top features.The point cloud target detection algorithm is trained using the annotated simulation dataset,and evaluated on a real dataset obtained from equivalent experiments.The proposed algorithm achieves an accuracy rate of 93.2% on the real dataset.The evaluated result indicates that the simulated data effectively reflect the true characteristics of the targets,and the dynamic imaging model has high credibility.

Space-variant Phase Compensation and Focusing Processing of High-speed Diving 3D Linear Array SAR

LIU Can, TAN Gewei

2025, 46(6):  240596.  doi:10.12382/bgxb.2024.0596

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The combination of 3D linear array synthetic aperture radar (SAR) and high-speed platform can achieve imaging in extreme scenarios.To achieve imaging under this SAR system with high-speed platform,it is necessary to overcome the more complex range migration and space-variant characteristics caused by high speed and large acceleration.This paper proposes an echo signal model and a slant range model suitable for 3D linear array SAR on high-speed platform,and uses the implicit function derivation method to achieve the acquisition of 3D frequency spectrum.To balance the azimuth and cross-track space-variant modulated phases,the least squares fitting method is employed for two-dimensional resampling operations in the azimuth and cross-track directions for completing the compensation for space-variant phase errors in these two dimensions.The proposed compensation algorithm based on least squares fitting can effectively eliminates the impact of space-variant phase errors on imaging,thereby enhancing the imaging performance of 3D linear array SAR in high-speed scenarios.Finally,the effectiveness of the proposed algorithm is verified through simulation experiment.

LiDAR Object Detection Method Based on Point Cloud Mask Pre-training and Gaussian Localization Uncertainty Estimation

FENG Yu, XIE Guangda, LIU Long, SU Yunquan, LIU Junwei, GENG Yandong, MIAO Lie

2025, 46(6):  240788.  doi:10.12382/bgxb.2024.0788

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The 3D point cloud data acquired by LiDAR is crucial for autonomous driving.However,the annotation of point cloud data is difficult;the available data is limited;and there is usually a high uncertainty in its labels,which constrain the training effects of deep learning-based 3D object detection models.To address these issues,this paper proposes a point cloud masking strategy to construct a pre-training dataset,which is combined with transfer learning to improve detection accuracy.Additionally,a Gaussian distribution-based localization uncertainty estimation modeling method is proposed,enabling the object detection model to predict the localization uncertainty of each coordinate while predicting the bounding box coordinates.Experimental results demonstrate that the proposed method effectively reduces the false detections and significantly improves the accuracy of object detection without significantly increasing algorithmic complexity.