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Air target recognition method against ISRJ for radio frequency proximity sensors using chaotic stream encryption

Defence technology（防务技术） 2023年第10期28卷 267-279页

作者： Jian-feng Li Jian Dai Xin-hong Hao Xiao-peng Yan Xin-wei Wang Science and Technology on Electromechanical Dynamic Control Laboratory School of Mechatronical EngineeringBeijing Institute of TechnologyBeijing100081China BIT Tangshan Research Institute Beijing100081China

The interrupted-sampling repeater jamming(ISRJ)can cause false targets to the radio-frequency proximity sensors(RFPSs),resulting in a serious decline in the target detection capability of the *** article proposes a recognition method for RFPSs to identify the false targets caused by *** proposed method is realized by assigning a unique identity(ID)to each RFPS,and each ID is a periodically and chaotically encrypted in every pulse *** processing technique of the received signal is divided into ranging and ID *** the ranging part,a high-resolution range profile(HRRP)can be obtained by performing pulse compression with the binary chaotic *** suppress the noise,the singular value decomposition(SVD)is applied in the *** ID decryption,targets and ISRJ can be recognized through the encryption and decryption processes,which are controlled by random *** adaptability analysis conducted in terms of the peak-to-side lobe ratio(PSLR)and bit error rate(BER)indicates that the proposed method performs well within a 70-k Hz Doppler shift.A simulation and experimental results show that the proposed method achieves extremely stable target and ISRJ recognition accuracies at different signal-to-noise ratios(SNRs)and jamming-to-signal ratios(JSRs).

关键词： Interrupted-sampling repeater jamming(ISRJ) Radio frequency proximity sensors(RFPS) Chaotic stream encryption Air target recognition Identity(ID)decryption

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The Application of Immune Genetic Algorithm in BP Neural Network 6

The Application of Immune Genetic Algorithm in BP Neural Net...

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6th IEEE International Conference on Intelligent Computing and Signal Processing, ICSP 2021

作者： Yichang, Zhao Science and Technology on Electromechanical Dynamic Control Laboratory Xi'an China

ISBN: (纸本)9780738143705

Randomly generating the initial weights and thresholds of the neural network will bring uncertainty to the network. We used genetic algorithms to optimize the initial weights and thresholds of the neural network. However, the genetic algorithm may have the problem of premature population maturity during its operation, that is, the algorithm has converged before reaching the global optimal solution. To this end, the immune genetic algorithm is used to optimize the initial weights and thresholds of the neural network to avoid premature maturity of the population. A binary classification problem model is established. From the simulation training results, the use of immune genetic algorithm to optimize the BP neural network can more effectively prevent the network from falling into a local minimum during training, improve the network convergence speed, and complete it more accurately and stably Two classification problems. © 2021 IEEE.

关键词： Genetic algorithms

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Investigation on Effect from variational Electromagnetic Parameters of absorbing patch for RCS of Almond model 13

Investigation on Effect from variational Electromagnetic Par...

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13th International Symposium on Antennas, Propagation and EM Theory, ISAPE 2021

作者： Li, Wei Li, Tie Huang, Dengdian Xie, Yue Science and Technology on Electromechanical Dynamic Control Laboratory Xian China

ISBN: (纸本)9781665418126

The RCS of the almond model which was affected by the change from electromagnetic parameters (ϵ and mu) of the absorbing patch was researched, and the moment method was utilized. The varepsilon andμ of the absorbing patch can be measured and the values were assumed to vary with equal difference in the interval of 5%30%, the measured values of varepsilon and mu worked as variable which were used to calculate the RCS of the almond model with the different varepsilon and mu of the patch. Here, two almond model RCS were obtained, one is circumferential RCS which generated by the gradient of varepsilon and mu of absorbing patch, and the other Radar Cross-Section (RCS) generated by the known electromagnetic parameter measurements. Comparing the two RCS mentioned above, the calculated results show that for the HH polarization, the undulation values of the almond model RCS vary within 0.4dB when the real part of varepsilon and mu of the absorbing patch vary within 5%-30% at 10GHz, and for the VV polarization, the undulation values changes within 2.5 dB, Moreover, the polar differences of both polarizations decrease with the increase of the real part of the varepsilon and mu, in both polarization modes, the polar RCS is sensitive to the variation of varepsilon and mu, and the VV polarization is much more sensitive than the HH polarization. © 2021 IEEE.

关键词： Radar cross section

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A noncontact method for UAV electrostatic charge measurement incorporating the influence of parasitic capacitance

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Measurement 2025年 254卷

作者： Zhongzheng He Sichao Qin Hanzhou Wu Bing Wang Yu Gong Xi Chen School of Mechatronical Engineering Beijing Institute of Technology Beijing 100081 China Science and Technology on Electromechanical Dynamic Control Laboratory China Beijing Institute of Special Mechanic-Electric Beijing 100012 China

During flight operations, unmanned aerial vehicles (UAVs) accumulate significant electrostatic charges, which may lead to electrostatic discharge events, potentially damaging onboard electronic systems and compromising flight safety. Accurate measurement of these accumulated charges is crucial for optimizing anti-static protection measures. First, a refined physical model for UAV charge measurement is proposed, which incorporates the influence of parasitic capacitance. The model utilizes the electrode’s spatial sensitivity to establish a quantitative relationship between the induced charge on the electrode and the UAV electrostatic charge. Then, a noncontact method for measuring UAV charge is proposed, utilizing the spatial sensitivity at the UAV’s position and the induced charge on the electrode to estimate the UAV charge. Further, experimental validation was conducted using electrometer measurements as the reference values. The results demonstrate strong correlation and consistency between measured and reference values, with measurement error maintained within ± 10 %. Finally, the proposed method was applied to measure the UAV charge, and its experiment result ranges from 9 to 18 nC. The proposed method accurately measures the UAV charge during flight and can be used to evaluate electrostatic discharge risk, providing a foundation for the anti-static design of UAVs and enhancing flight safety.

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Underwater four-quadrant dual-beam circumferential scanning laser fuze using nonlinear adaptive backscatter filter based on pauseable SAF-LMS algorithm

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Defence technology（防务技术） 2024年第7期37卷 1-13页

作者： Guangbo Xu Bingting Zha Hailu Yuan Zhen Zheng He Zhang Ministerial Key Laboratory of ZNDY Nanjing University of Science and TechnologyNanjing 210094China Science and Technology on Electromechanical Dynamic Control Laboratory Beijing 100081China Shanghai Radio Equipment Research Institute Shanghai 201109China

The phenomenon of a target echo peak overlapping with the backscattered echo peak significantly undermines the detection range and precision of underwater laser *** overcome this issue,we propose a four-quadrant dual-beam circumferential scanning laser fuze to distinguish various interference signals and provide more real-time data for the backscatter filtering *** enhances the algorithm loading capability of the *** order to address the problem of insufficient filtering capacity in existing linear backscatter filtering algorithms,we develop a nonlinear backscattering adaptive filter based on the spline adaptive filter least mean square(SAF-LMS)*** also designed an algorithm pause module to retain the original trend of the target echo peak,improving the time discrimination accuracy and anti-interference capability of the ***,experiments are conducted with varying signal-to-noise ratios of the original underwater target echo *** experimental results show that the average signal-to-noise ratio before and after filtering can be improved by more than31 d B,with an increase of up to 76%in extreme detection distance.

关键词： Laser fuze Underwater laser detection Backscatter adaptive filter Spline least mean square algorithm Nonlinear filtering algorithm

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V-band antipolar fin line microstrip waveguide conversion structure 13

V-band antipolar fin line microstrip waveguide conversion st...

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13th International Symposium on Antennas, Propagation and EM Theory, ISAPE 2021

作者： Chen, Wei Wen, Rui-Hu Zheng, Xiao-Yan Liu, Shui-Ying Niu, Lan-Jie Science and Technology on Electromechanical Dynamic Control Laboratory Xi'an710065 China

ISBN: (纸本)9781665418126

The V-band microstrip waveguide conversion structure cannot meet the requirements of simple installation and integrated design. The fin line structure with specific size and shape is etched on the surface of the film. By adjusting the parameters of the opposite pole fin line, the conversion structure can meet the requirements of practical performance. The test results show that the center frequency of antipolar fin line microstrip waveguide conversion structure is 71.6GHz, the internal reflection parameter S11 is less than -20dB in the bandwidth of 67.3-77.0GHz and 10GHz, and the conversion structure size is 6.56mm*1.47mm*0.127mm. The conversion structure is installed in the middle of the V-band waveguide along the E-plane of the waveguide, without slotting the waveguide wall, which meets the requirements of superior performance, simple installation and integrated design. © 2021 IEEE.

关键词： Fins (heat exchange)

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Research on a fuze anti-jamming strategy under the background of complex ground objects 13

Research on a fuze anti-jamming strategy under the backgroun...

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13th International Symposium on Antennas, Propagation and EM Theory, ISAPE 2021

作者： Xia, Lei Dai, Liang Zou, Jin-Long Science and Technology on Electromechanical Dynamic Control Laboratory Xi'an710065 China

ISBN: (纸本)9781665418126

Aiming at the problem of the reduced reliability of the radio proximity fuze under the jamming of complex ground objects,a method of fixed height for laser and radio combined detection is proposed. Using the method of dual-beam separate airspace detection and information fusion,a mathematical model of the fuze's fixed height initiation is established. Through the analysis of the dynamic ground detection model and the ground objects jamming detection model, this design idea and mathematical model against the ground objects jamming effectiveness are confirmed. © 2021 IEEE.

关键词： Object detection

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MEMS slide block locking mechanism based on elastic supporting structure

MEMS slide block locking mechanism based on elastic supporti...

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2012 2nd International Conference on Manipulation, Manufacturing and Measurement on the Nanoscale, 3M-NANO 2012

作者： Chenyang, Fan Xiaojie, Li Falin, Wang Science and Technology on Electromechanical Dynamic Control Laboratory xi'an 702265 China

ISBN: (纸本)9781467345897

Aiming at the condition that when the Fuze MEMS (micro electro mechanical system) S&A system bears setback/centrifugal overload in an experiment, the clamping head of a setback/centrifugal slide block deforms considerably when entering the clamping seat of a base plate, so that the slide block cannot be locked successfully by the clamping seat of the base plate, this paper presents an MEMS slide block locking mechanism with an elastic supporting structure. The structure of the mechanism, which is contrary to the original structure, is that rigid barbs are arranged on the clamping head, and an elastic supporting arm is arranged on the base plate. The finite element simulation with ANSYS shows that when the clamping head and the clamping arm of the locking mechanism with the elastic supporting structure bear overload, the stress of the dangerous cross-section of the locking mechanism is reduced by 52%, compared with that of the original mechanism, so that plastic deformation is avoided, and the slide block can enter the clamping seat smoothly and locked. Therefore, it can provide selection and reference for the design of locking mechanisms of MEMS S&A system in future. © 2012 IEEE.

关键词： Finite element method

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Research on dynamic response behavior of the fuze with a combined fuze-warhead structure under different impact positions of bullets 4

Research on dynamic response behavior of the fuze with a com...

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4th International Conference on Defence technology, ICDT 2024

作者： Wang, Qiang Niu, Lanjie Fan, Chenyang Qv, Zhuojun Xv, Rui Science and Technology on Electromechanical Dynamic Control Laboratory Xi’an Institute of Electromechanical Information Technology Xi’an China

Aiming at the problem of unclear fuse detonation response in the process of different positions of the bullet impact detonator, to carry out research on the dynamic response behaviour of the fuse under the difference of the bullet impact position of the fuze-warhead combination structure. Through experiments and LS-DYNA numerical simulation, the influence of different positions of bullet impact booster on fuze reaction level and output pressure is analyzed. The results demonstrate that in the tests where the bullet made contact with the centre of the fuse, transmitting an explosive charge, the velocity of the bullet is 832 m/s, and the fuse exhibits a partial detonation level in response to the impact. The highest fuse response level occurs when the bullet strikes the centre of the pyrotechnic charge - partial detonation, the lowest fuse response level occurs when the bullet strikes the upper side of the pyrotechnic charge - burning, and the fuse response level occurs when the bullet strikes the lower side of the pyrotechnic charge - deflagration or explosion. The maximum fuse output pressure when the bullet strikes the centre of the pyrotechnic charge - 6.09 GPa, the minimum fuse output pressure when the bullet strikes the upper side of the pyrotechnic charge - 0.98 GPa, and the fuse output pressure when the bullet strikes the lower side of the pyrotechnic charge is 2.76 GPa. © 2024 Institute of Physics Publishing. All rights reserved.

关键词： Detonation

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Automatic modulation recognition of radio fuzes using a DR2D-based adaptive denoising method and textural feature extraction

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Defence technology（防务技术） 2024年第4期34卷 328-338页

作者： Yangtian Liu Xiaopeng Yan Qiang Liu Tai An Jian Dai Science and Technology on Electromechanical Dynamic Control Laboratory School of Mechatronical EngineeringBeijing Institute of TechnologyBeijing 100081China China Research and Development Academy of Machinery Equipment Beijing 100089China

The identification of intercepted radio fuze modulation types is a prerequisite for decision-making in interference ***,the electromagnetic environment of modern battlefields is complex,and the signal-to-noise ratio(SNR)of such environments is usually low,which makes it difficult to implement accurate recognition of radio *** solve the above problem,a radio fuze automatic modulation recognition(AMR)method for low-SNR environments is ***,an adaptive denoising algorithm based on data rearrangement and the two-dimensional(2D)fast Fourier transform(FFT)(DR2D)is used to reduce the noise of the intercepted radio fuze intermediate frequency(IF)***,the textural features of the denoised IF signal rearranged data matrix are extracted from the statistical indicator vectors of gray-level cooccurrence matrices(GLCMs),and support vector machines(SVMs)are used for *** DR2D-based adaptive denoising algorithm achieves an average correlation coefficient of more than 0.76 for ten fuze types under SNRs of-10 d B and above,which is higher than that of other typical *** trained SVM classification model achieves an average recognition accuracy of more than 96%on seven modulation types and recognition accuracies of more than 94%on each modulation type under SNRs of-12 d B and above,which represents a good AMR performance of radio fuzes under low SNRs.

关键词： Automatic modulation recognition Adaptive denoising Data rearrangement and the 2D FFT(DR2D) Radio fuze

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