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4th International Conference on Defence technology, ICDT 2024

作者： Lv, Sining Lou, Wenzhong Feng, Hengzhen Xiao, Chuan Li, Shiyi Science and Technology on Electromechanical Dynamic Control Laboratory School of Mechatronical Engineering Beijing Institute of Technology Beijing China

Metal Additive Manufacturing (MAM) technology has become an important means of rapid prototyping of special high dynamic complex components. This study employs selective laser melting (SLM) as a technological approach for investigating micro-sized high dynamic components. The parameters that affect SLM process are analysed, mainly including laser power, laser speed, laser diameter, and scan spacing. Based on prior studies, feasible parameter ranges are identified, and an orthogonal experimental design table is established for simulation and experimental co-verification. Range and variance analysis are conducted and the influence ability of each influencing factor is explored from both simulation and experimental aspects. The SLM process model is established using finite element software, taking into account parameters such as residual stress and maximum deformation. The conclusion is drawn that the order of influence of each factor on the preparation of micro-sized high dynamic components is: scan spacing>laser power>laser diameter> laser speed. Samples of components are fabricated and subjected to static testing. The density of the components can reach over 99.15%, and the structural strength can reach 348 MPa, which meet the required standards and confirm the simulation analysis. The results demonstrates that SLM provides a novel manufacturing method for micro-sized high dynamic components. © 2024 Published under licence by IOP Publishing Ltd.

关键词： Selective laser melting

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Adaptive Cancellation Method of Pseudo Code Phase Modulation Fuze Leakage Noise 6

Adaptive Cancellation Method of Pseudo Code Phase Modulation...

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6th IEEE Information technology and Mechatronics Engineering Conference, ITOEC 2022

作者： Wang, Qihai Xue, Chao Pan, Xi Beijing Institute of Technology Key Laboratory of Electromechanical Dynamic Control Beijing China

ISBN: (纸本)9781665431859

The leakage noise of the pseudo-code phase modulation fuze system is the noise interference caused by the insufficient isolation of the radio frequency part. Since the leakage signal is similar to the echo signal waveform, it will affect the output of the correlator and lead to misjudgment of the fuze. In this paper, the pseudo-code phase modulation fuze's emission leakage signal is modeled, and its characteristics are analyzed, and an adaptive noise cancellation method for the pseudo-code phase modulation leakage signal is proposed. The algorithm simulation shows that the noise filtering effect is good. Pseudo-code phase modulation fuze prototype is used to actually test the algorithm. The algorithm can increase the correlation peak value of the actual target signal and reduce the influence of leakage noise and natural noise floor. © 2022 IEEE.

关键词： Adaptive filters

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High-Efficiency Graphene Photo Sensor Using a Transparent Electrode

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Chinese Physics Letters 2011年第10期28卷 192-194页

作者： LIU Tao HUANG Zheng National Key Laboratory for Electronic Measurement Technology and Key Laboratory of Instrumentation Science and Dynamic Measurement North University of ChinaTaiyuan 030051 Xi'an Institute of Electromechanical Information Technology Xi'an 710065

We report the first implementation of transparent electrodes in bottom-gate graphene transistors used for photo *** to conventional nontransparent electrodes,the transparent electrodes allow photons to transmit through to the graphene beneath,providing an enlarged absorption area and thereby giving rise to an enhancement of photocurrent *** devices are fabricated with an asymmetric metallization scheme and the experimental results show that the maximum photocurrent density using the transparent electrodes(ITO and Pd/ITO)is over two times higher than that using the nontransparent electrodes(Ti and Pd),indicating a significant enhancement in the performance of graphene photo sensors.

关键词： transparent thereby asymmetric

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Backscattering characteristics of forest canopy for radio fuze 4

Backscattering characteristics of forest canopy for radio fu...

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2022 4th International Conference on Electronic Engineering and Informatics, EEI 2022

作者： Liu, Bing Hao, Xinhong Chen, Yanjun Science and Technology on Electromechanical Dynamic Control Laboratroy Beijing Insitute of Technology Beijing China

ISBN: (纸本)9783800759231

When the radio fuze is used in a forest environment, it is susceptible to interference from strong canopy backscattering clutter. In order to study the electromagnetic backscattering characteristics of the forest canopy and improve the ability of the radio fuze to anti forest clutter interference, based on the MIMICS theroy, the backscattering coefficients of radio fuzes under different incident angles, electromagnetic frequencyies, forest canopy height and forest canopy water content are analyzed. The influence model of backscattering coefficient on radio fuze echo wave amplitude is established to provide a basis for determining the optimal burst height. The result can be applied to the parameter optimization design of radio fuze against forest canopy backscattering. © VDE VERLAG GMBH ∙ Berlin ∙ Offenbach.

关键词： Backscattering

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Research on Numerical Simulation of the instantaneity of a Mechanical Impact Fuze 4

Research on Numerical Simulation of the instantaneity of a M...

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4th International Conference on Defence technology, ICDT 2024

作者： Yang, Shanglin Wang, Yabin Luan, Donglin Guo, Pengda School of Mechatronical Engineering Beijing Institute of Technology Beijing China Science and Technology on Electromechanical Dynamic Control Laboratory China

The instantaneity of a fuze refers to the time interval between the projectile's impact on the target and the completion of detonation. This parameter is a critical indicator for evaluating the performance of ammunition. To investigate the factors influencing instantaneity, a numerical simulation was conducted on the process of a projectile striking a target under different conditions, including impact angle, fuze material, and target material. The simulation results, under 12 different conditions, produced acceleration curves and instantaneity for the firing device. Through the analysis of the results, the study establishes key design principles for the firing device of the fuze: the protection design of the ignition device and the selection of the ignition strategy should consider the maximum and minimum impact angles and target hardness. Choosing an ignition device with a low structural strength or a fuze body material with lower hardness and strength can enhance the fuze's instantaneity The target hardness and impact angle greatly affect the fuze's instantaneity of the fuze, and appropriate structural strength should be selected in the design. © 2024 Institute of Physics Publishing. All rights reserved.

关键词： Projectiles

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Simulation and Analysis of Position Change Deviation of Equivalent Measurement of Time Domain Transient Magnetic Field Differential Probe 17th

Simulation and Analysis of Position Change Deviation of Equi...

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17th Annual Conference of China Electrotechnical Society, CES 2022

作者： Li, Fadong Cao, Ronggang Li, Jiawu Cao, Yuxi Zhou, Yu Zhang, Anqi Science and Technology On Electromechanical Dynamic Control Laboratory Beijing Institute of Technology Beijing100081 China Tangshan063611 China

ISBN: (纸本)9789819903566

This paper used Ls-Dyna to simulate the measurement process of the differential probe in the time-domain transient magnetic field, then figure out the displacement-time and velocity-time data measured by the differential probes. There is a variation in the equivalent measurement position of the differential probes by comparing the displacement data of the probes with the corresponding simulation values. From the simulation results. In the previous phase of the armature acceleration, the probe displacement deviates significantly from the simulated value;with the increase of the armature velocity, this value fluctuates;at the telophase of acceleration, the displacement difference is negligible. The equivalent displacement deviation of the corresponding simulation value shows positive and negative fluctuations based on the displacement difference of adjacent probes. Excluding extreme cases, the absolute value of the deviation is within 5%;at the acceleration telophase, it is within 2%. This deviation makes the output of the differential probes inaccurate in the time domain, which is significant for the related experiments when measuring the transient information of the armature motion in the electromagnetic launch by the differential probe. © 2023, Beijing Paike Culture Commu. Co., Ltd.

关键词： Probes

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Low SNR FM signal preprocessing method based on low-order cyclic statistics and WVD distribution 2

Low SNR FM signal preprocessing method based on low-order cy...

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2nd International Conference on Robotics, Artificial Intelligence and Intelligent control, RAIIC 2023

作者： Li, Jianfeng Huang, Dingkun Yan, Xiaopeng Dai, Jian Beijing Institute of Technology Science and Technology on Electromechanical Dynamic Control Laboratory School of Mechatronical Engineering Beijing100081 China

ISBN: (纸本)9798350328004

In order to solve the problem of poor noise suppression effect and long processing time of FM signal under the condition of low SNR by traditional preprocessing methods, a signal preprocessing method based on low-order cyclic statistics and WVD distribution is proposed. The method firstly calculates the cyclic mean value of incoming wave signal, and then transforms the incoming wave signal domain through IFFT algorithm with variable points. Finally, the time-frequency ridge of the FM signal is obtained by WVD time-frequency analysis, and the binary image transformation is carried out. Through simulation analysis, the time-frequency preprocessing method proposed in this paper can greatly reduce the calculation amount and improve the real-time performance while retaining the accuracy of time-frequency features, and provide effective support for subsequent sorting identification and parameter estimation. © 2023 IEEE.

关键词： Binary images

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Accurate azimuth estimation method for FMCW radar based on moving arrays

Accurate azimuth estimation method for FMCW radar based on m...

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2024 International Conference on Image, Signal Processing, and Pattern Recognition, ISPP 2024

作者： An, Tai Yan, Xiaopeng Han, Yanwen Dai, Jian Wang, Jiawei Science and Technology on Electromechanical Dynamic Control Laboratory School of Mechatronical Engineering Beijing Institute of Technology Beijing100081 China

ISBN: (纸本)9781510680425

Addressing the current challenges of weak target azimuth detection and inadequate precision in frequency modulated continuous wave (FMCW) radar systems, this paper proposes a novel method for precise imaging based on a motion array using FMCW radar for accurate range and azimuth estimation. The approach involves the use of a millimeter-wave FMCW radar with a motion array to capture target angular information, leading to a substantial improvement in azimuth estimation resolution, particularly for munitions. Additionally, spatial Fourier transform array signal processing is employed to achieve two-dimensional precise imaging of radar targets, encompassing both range and azimuth dimensions. Experimental results validate the effectiveness of the proposed approach, showcasing an enhanced angular resolution of the millimeter-wave radar, reaching 2.6°. The method demonstrates favorable azimuth estimation outcomes in diverse scenarios, including those involving multiple and planar targets. Overall, the introduced technique significantly elevates the precise detection capability of automotive millimeter-wave radar systems. © 2024 SPIE.

关键词： Radar imaging

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Research on the performance optimisation method of linear array infrared detector based on pixel decomposition 4

Research on the performance optimisation method of linear ar...

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4th International Conference on Defence technology, ICDT 2024

作者： Hu, Shiyuan Wu, Yanjiang Si, Xinlu Han, Shaorong Chen, Huimin Science and Technology on Electromechanical Dynamic Control Laboratory Beijing Institute of Technology Beijing100081 China Xi'an Institute of Electromechanical Information Technology Xi'an710065 China

Facing the background of proximity detection applications, this paper proposes an optimisation method based on pixel decomposition to improve the detection performance in view of the strong dark current and blind pixel rate problems brought by the increase of pixel size. By establishing the linear array infrared detection model, the influence of pixel size on detector system dynamic range, noise equivalent temperature difference, spatial resolution and other performance parameters is obtained. Based on the idea of pixel decomposition, a suitable resolution is chosen to decompose a large-size pixel, and the photoelectric conversion process of each sub-pixel is equated. The simulation verifies that the proposed optimisation method of the pixel decomposition improves the detection signal-to-noise ratio. © 2024 Institute of Physics Publishing. All rights reserved.

关键词： Infrared detectors

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Research on ground target detection method under foliage shade

Research on ground target detection method under foliage sha...

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2022 International Conference on Image, Signal Processing, and Pattern Recognition, ISPP 2022

作者： Wan, Yi Chen, Qile Zhang, Jiaxu Chen, Yanjun Guan, Enming Science and Technology on Electromechanical Dynamic Control Laboratory School of Mechatronical Engineering Beijing Institute of Technology Beijing100081 China

ISBN: (纸本)9781510654846

As the main product of fuze equipment, radio fuze has the advantages of strong anti-interference ability and high precision. In the face of increasingly complex battlefield environment, radio fuze is more and more susceptible to environmental interference, which makes the explosion point walk larger and lose the best damage effect. The fuze needs to be able to actively identify the environment and make decisions. Like the dense jungle at the end of the trajectory would interfere with fuze control of the blast site. To further address the issues raised by this situation,this paper analyzes the Michigan microwave vegetation scattering model and summarizes the advantages and disadvantages of the fuze platform. The echo model of leaf cluster based on pendulum model is proposed, and the echo micro-Doppler characteristics of different blade sizes are simulated. The characteristics of the two methods are summarized, which lays a foundation for further analysis of fuze echo signal. © 2022 SPIE.

关键词： Tracking radar

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