Modern Defense Technology

Characteristic Analysis of Magnetic Field Before Armature and Its Magneto-Dynamic Effect on Armature of Electromagnetic Railgun

LI Tian-liang, YIN Da-hu, CHEN Lang-zhong, QIAO Peng-peng

2021, 49(4): 1-6. doi:10.3969/j.issn.1009-086x.2021.04.001

Asbtract ( 1747 )

PDF (1067KB) ( 1171 )

References | Related Articles | Metrics

Armature is the critical moving part of electromagnetic railgun,which is also the intermediary that converts electromagnetic energy of the railgun into kinetic energy of the projectile.The current and induced magnetic field in front of the armature are the fundamental reasons for the armature movement and directly determine the energy conversion rate of the railgun system.Based on uniform current hypothesis,the electromagnetic force model of the armature and the calculation model of electromagnetic induction intensity field in front of armature are established without considering the rail resistance and current skin effect.Based on the simulation results, the characteristics of magnetic induction intensity field are studied,and the effects of current length on armature magneto-dynamic force are analyzed.

Analysis on the Development of Medium and Large Sized Unmanned Surface Vehicle and Formation Coordinated

WANG De-chao, JIN Xiao, CHEN Zhe-liang, ZHAO Zheng-dang

2021, 49(4): 7-14. doi:10.3969/j.issn.1009-086x.2021.04.002

Asbtract ( 918 )

PDF (8965KB) ( 455 )

References | Related Articles | Metrics

The current unmanned trend on the battlefield becomes increasingly obvious,and various types of unmanned equipment have played a huge role in reconnaissance, strike and support.However,the unmanned surface vehicles (USV),due to the technical complexity,started late in development,which have a lower level of maturity than other unmanned equipment and less actual combat in battlefield applications and currently still focusing on trial and test.By sorting out the current overseas manned/unmanned cooperation projects,the roles of medium and large unmanned USV in the manned/unmanned formation are envisioned,and a new coordinate mode of the future manned warship and medium-to-large sized USV formation operation on the ocean is established.The ability advantages of this mode in actual combat are analyzed,and the key technologies faced by future operational applications are proposed to provide reference for future maritime combat model innovation.

Decision Tree Integration Method Application in Effectiveness Evaluation of Anti-Ship Missile Weapon System

JI Zheng-yi, CHEN Yang, SHEN Pei-zhi, HAN Xian-ping, QI Hong-kun

2021, 49(4): 15-23. doi:10.3969/j.issn.1009-086x.2021.04.003

Asbtract ( 626 )

PDF (2051KB) ( 391 )

References | Related Articles | Metrics

Methods based on random forest and gradient boosting regression tree are proposed in order to improve the problem of subjective experience and high cost of calculation time in the effectiveness evaluation of anti-ship missile.By constructing a 3-layer and 19-component anti-ship missile effectiveness evaluation index system,240 operational parameter data samples of anti-ship missile in different states are set up by the improved ADC evaluation model,then the data set is segmented and normalized,combining with cross validation and grid search,two ideal decision tree integration effectiveness evaluation models are obtained.In the simulation test,the accuracy of the two models is high,which proves the practicability of the method and provides new ideas for anti-ship missile effectiveness evaluation.

Study on the Influence of Clearances in Airborne Store Vibration

LIU Xiang-qiu, LIU Kai, ZHANG Hong-bo

2021, 49(4): 24-27. doi:10.3969/j.issn.1009-086x.2021.04.004

Asbtract ( 348 )

PDF (936KB) ( 416 )

References | Related Articles | Metrics

In hanging flight Environment,the nonlinear vibration of aircraft stores is induced by the clearances between the missiles and launchers.Aiming at above problem,the dynamic model of a aircraft store is established.The influence on vibration of the clearance between the missile and launcher is studied theoretically.The vibration responses of various clearances are simulated respectively.The influence trend on vibration response of variation clearance is obtained.The simulation results show that the peak frequency components of the vibration response in the low frequency band are complex,and the vibration response decreases initially and then increases along with the clearance increasing.The peak values of vibration response for various clearances have no distinct difference in mid-frequency band.In higher frequency band, the response decreases along with the clearance increasing.

The Micro Ultrasonic Motor Driver Based on Resonant Boost Circuit

XU Hao-tong, WANG San-zhou, HUANG Bo-chao, JI Ye, XU Nuo

2021, 49(4): 28-34. doi:10.3969/j.issn.1009-086x.2021.04.005

Asbtract ( 497 )

PDF (1838KB) ( 317 )

References | Related Articles | Metrics

According to the application prospect of the miniaturized ultrasonic motor,and focusing on the miniaturization problem of the ultrasonic motor driving circuit,a miniaturized driving circuit based on resonant boost principle is designed.To reduce the colume of the driving circuit,the resonant boost and micro half-bridge inverter are applied to exclude the transformers which are difficult to be miniaturized.Based on the modeling of the ultrasonic motor equivalent circuit and the analysis of the LC resonant circuit,the driving circuit output waveform,the selection of the best matching inductor and the influence of real inductance are researched.The resonant boost output waveform is analyzed based on Matlab/Simulink simulation platform.The driving performance of the resonant boost circuit on the columnar traveling wave type ultrasonic motor is verified by experiments.The experimental results show that the performance meets expectation,and the size is much smaller than the traditional driving circuit with transformers.

Application of UKF Filter Algorithm in Solving Two-Point Boundary Value Problem

ZANG Jie, LIU Sheng-gang

2021, 49(4): 35-42. doi:10.3969/j.issn.1009-086x.2021.04.006

Asbtract ( 430 )

PDF (883KB) ( 287 )

References | Related Articles | Metrics

Application of unscented Kalman filter (UKF) algorithm in solving two-point boundary value problem (TPBVP) is a key technology in the indirect method of optimization problem solving algorithms,and usually the final solution can only be given through numerical iteration methods.Due to the high sensitivity and strong nonlinear dynamic characteristics of the two-point boundary value problem,the accuracy of the initial value of the numerical iteration is required to be very high,otherwise it is difficult to obtain a convergent solution.In order to reduce the requirements of the initial value accuracy,based on the UKF algorithm,an optimal parameter estimation method is given,which can be used to solve the two-point boundary value problem.This method adopts Gaussian distribution model,which can describe the original nonlinear problem with accuracy of second order or higher,and has a larger convergence range and stronger robustness.The example of spacecraft trajectory optimization verifies the effectiveness and reliability of this algorithm.

Research on PMSM Control Based on Optimized Neural-Net PID

YAN Hao-an, LI Jian-dong

2021, 49(4): 43-48. doi:10.3969/j.issn.1009-086x.2021.04.007

Asbtract ( 568 )

PDF (942KB) ( 337 )

References | Related Articles | Metrics

Permanent synchronous motor is a highly coupling non-linear time-varying system.In view of the traditional PID control method cannot fully exploit the advantages of fast response and high accuracy of maximum torque to current ratio control of Interior PMSM,an optimized PID tuning method with neural net based on differential evolution algorithm is proposed,and proved by Matlab/Simulink simulation model.Compared with traditional PID,the result turns out that the proposed method performs better in precision and dynamics.

Track Association in Distributed 2D Radar Network

TAN Shun-cheng, CHEN Zhong-hua, YU Hong-bo

2021, 49(4): 49-55. doi:10.3969/j.issn.1009-086x.2021.04.008

Asbtract ( 422 )

PDF (750KB) ( 401 )

References | Related Articles | Metrics

Due to the lack of altitude information,aircraft targets can not be made track association by the distributed 2D radar network.A novel track association algorithm for 2D and 2D radar is proposed.The tracks coming from two radars belong to different places are united based on geometrical features of radars and target,and association function is created.The linear relationship between association function and radar measurement noise is built with the first-order of Taylor expansion of the association function,and the association threshold is obtained according to the confidence interval of measurement noise.The association cost matrix based on historical information is established after rough track association,and precise track association is realized through optimal assignment with Hungary algorithm.Simulation results demonstrate that the proposed method can solve the track association in distributed 2D radar network effectively,and be of certain practical application value.

Research on Physical and Functional Damage Assessment of Phased Array Antenna

ZHOU Li, SHI Jian, ZHANG Qing-bo, CHEN Guang-yang, YANG Shuang-ling

2021, 49(4): 56-63. doi:10.3969/j.issn.1009-086x.2021.04.009

Asbtract ( 324 )

PDF (10631KB) ( 249 )

References | Related Articles | Metrics

To deal with the difficulties in physical damage information extraction and functional damage assessment in damage assessment of phased array antenna,an intelligent damage assessment method is explored by using computer vision and phased array antenna simulation technology.On the basis of space reconnaissance images,the position of damaged array elements is extracted by computer vision technology,and the physical damage results are obtained.According to the position information of the array elements,the antenna model is built in the Matlab environment,and the changes of detection distance and anti-jamming before and after the attack are simulated and compared to obtain the functional damage.The simulation results show that the proposed method can better extract the physical damage information and build the mapping relationship between physical damage and functional damage through software simulation.The relevant research results provide a new method and idea for intelligent and rapid phased array antenna damage assessment.

The Effect of Stealth Aircraft Bombing on the Leading Angle Error of Air Defense Weapon

LIU Ming-jie, WANG Chun-yang, ZENG Hui-yong, BAO Lei, PAN Xin-rui, ZHOU Chang-lin

2021, 49(4): 64-71. doi:10.3969/j.issn.1009-086x.2021.04.010

Asbtract ( 292 )

PDF (1350KB) ( 349 )

References | Related Articles | Metrics

Aiming at the problem of insufficient analysis of the impact of stealth aircraft bombing on the launch of air defense system weapons,a weapon launch front angle error model is proposed.Set the normal flight path and the bomb dropped flight path of the stealth aircraft,extract the RCS (radar cross section) sequence according to the two-dimensional attitude of the aircraft in real time,and combine the radar measurement error model to compare and study the target parameter measurement error under two flight paths.The mechanism of the measurement error affecting the air defense weapon system prediction of the weapon launch lead angle is analyzed,and a judgment criterion for judging the effect of the lead angle error is established.The simulation results show that during the dropping of stealth aircraft,the radar parameter measurement error of the aircraft is small,which makes the prediction of the launch front angle of air defense weapons more accurate,and lays the foundation for subsequent weapons to accurately intercept targets.

Observability and Simulation Analysis of Fixed Single Observer Passive Location

XIANG Fei-hua, WANG Jie-gui

2021, 49(4): 72-78. doi:10.3969/j.issn.1009-086x.2021.04.011

Asbtract ( 284 )

PDF (901KB) ( 243 )

References | Related Articles | Metrics

To solve the difficulty of analyzing the observability of fixed single station passive location in strongly nonlinear systems,an analysis method based on linear system observability theory is proposed.Taking the target azimuth,azimuth change rate and Doppler frequency change rate as observations,the complex Jacobian matrix is avoided by pseudo-linearization of the observation equation.Observable analysis of uniform velocity,uniform acceleration linear motion and uniform turning motion leads to observable conditions and provides theoretical premise for further research.Simulations examples are given to verify the correctness of the theoretical analysis of observability.

Design and Implementation of Acquisition Processor in Detector for Marine Environment Elements

FENG Jian-feng, WANG Li-chun, LUAN Ying-hong, LI Dan, ZHAO Feng

2021, 49(4): 79-85. doi:10.3969/j.issn.1009-086x.2021.04.012

Asbtract ( 235 )

PDF (5209KB) ( 314 )

References | Related Articles | Metrics

The detection of marine environment elements include surface temperature,salinity,ice thickness,significant wave height etc.Usually,marine environment elements are detected by microwave radiometer.High resolution and sensitivity radiometer normally has wide signal bandwidth,multi-channel,hybrid system for acquisition,correlation and inversion processing with distributed and classification strategy.According to the project requirements,the design and realization of detector with multi-channel acquisition and processing unit for marine environment elements are highlighted.The test and verification are combined with radiometer system and acquisition and processing unit.The results show that the designed multi-channel acquisition and processing unit can correctly acquire and process the broadband signal at 400 MHz,assist the digital correlator to realize the interference processing,and complete the extraction of inversion imaging parameters.

The Present Situation and Suggestion of Missile Equipment Natural Environmental Test

LIU Yan, CHEN Jiang-pan, LIU Yi, SUN Li-min, ZHANG Wei-wen, WANG Dong

2021, 49(4): 86-90. doi:10.3969/j.issn.1009-086x.2021.04.013

Asbtract ( 385 )

PDF (710KB) ( 301 )

References | Related Articles | Metrics

At present,the impact of long-term natural environmental effects on missile equipment is getting increasingly attention by more and more equipment development affiliations,and a large number of natural environmental tests have been carried out for multi-level products to verify and evaluate the adaptability of natural environment.In order to more effectively implement and promote the natural environmental test work for equipment,the natural environmental test requirements,test types,test technology development and its application of typical missile equipment are demonstrated on the basis of both characteristics and weak links of typical missile equipment.Moreover,as to the problems encountered in the implementation of current natural environmental test,the development suggestions of missile equipment natural environmental test technology are put forward in terms of system planning,data mining,research and application of accelerated test technology.

Missile Condition Evaluation and Decision Based on Improved Grey Relational Analysis with Combination Weighting

LI Hai-jun, XU Ting-xue

2021, 49(4): 91-98. doi:10.3969/j.issn.1009-086x.2021.04.014

Asbtract ( 234 )

PDF (903KB) ( 270 )

References | Related Articles | Metrics

For the problem of missile condition evaluation and decision,a method of missile condition evaluation and decision based on improved grey relational analysis with combination weighting is proposed.By analyzing the influencing factors of missile state,the index system of missile state parameters is constructed.On this basis,the improved grey relational analysis method is used to evaluate the missile state and make decision.Because the grey correlation analysis can only give the order of the correlation coefficient of the missile state to be selected,it can not reflect the real state of the missile.It is improved by introducing the lowest state parameter comparison sequence to obtain the objective missile state.The determination of gray relational analysis index weights is a key factor in determining the accuracy of the evaluation.In order to balance the advantages and disadvantages of subjective weighting and objective weighting,the weight determination scheme of the combination of Fuzzy AHP and entropy weight method is used.Through the analysis of an example and comparison with traditional methods,the feasibility and accuracy of the method are verified.

Self-Evaluation Method of Long-Range Rocket Simulation Training Results Based on Optimized AHP

YAO Kai, HUANG Shao-luo, WANG Jin-sheng, LIU Yue-he

2021, 49(4): 99-106. doi:10.3969/j.issn.1009-086x.2021.04.015

Asbtract ( 222 )

PDF (959KB) ( 269 )

References | Related Articles | Metrics

Aiming at the problems of imperfect performance evaluation indexes and difficulties in computer evaluation of existing simulation training system,a simulation training performance evaluation model based on improved analytic hierarchy process (AHP) is proposed.Starting from the actual operation of long-range rocket weapons and equipment,a simulation training performance evaluation system is constructed,which takes accuracy,proficiency,influence and mental outlook as evaluation indexes.By adopting the improved analytic hierarchy process,the inter-class coefficient and intra-class coefficient are introduced to optimize the ratio of experts,and the mathematical model of simulation system training performance evaluation is established.The effectiveness of the model is verified by the comparative analysis of the simulation training system,and the final results of the trainees are obtained.The results show that this method can quantify the evaluation index and decompose the final score,which has certain reference value for improving the efficiency of performance evaluation of equipment simulation system.

Monitoring and Testing Methods for Composite Shell of Solid-Propellant Rocket Engine

WU Hao, DU Peng-cheng, WANG Hua-bin

2021, 49(4): 107-114. doi:10.3969/j.issn.1009-086x.2021.04.016

Asbtract ( 303 )

PDF (4358KB) ( 377 )

References | Related Articles | Metrics

The carbon-fiber composite shell is an important part of solid-propellant rocket engine.The structural integrity of the shell is one of the key research objects in the field of health monitoring and testing for solid-propellant rocket engine.The methods and research progress of nondestructive testing and health monitoring of carbon-fiber composite and shell in recent years are reviewed,and the crucial technologies of health monitoring and testing are sumarized.The development direction of health monitoring for solid-propellant rocket engine shell is pointed out.

Table of Content