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2021 5th International Conference on Fluid Mechanics and Industrial Applications, FMIA 2021

作者： Ma, Guangsong He, Guanglin Zhang, Yulong Qiao, Zenghui Science and Technology on Electromechanical Dynamic Control Laboratory Beijing Institute of Technology Beijing China PLA Strategic Support Force Beijing10081 China

To study the forming characteristics of the multiple explosively formed projectile (MEFP) warhead of the small-caliber grenade with the integrated design of the liner and shell, the liner thickness is less than the shell thickness as the research object, and LS-DYNA is used for numerical simulation. On this basis, the influence of the curvature radius and the center thickness of the liner on the forming results of the projectile is further studied, and the integrated design of the MEFP forming result and the separate design were compared and analyzed. The simulation results show that, when the liner thickness structure is smaller than the shell thickness, the projectile shape is better. The shape of MEFP with the integral design is better than the separate design, and the forming velocity of the integral design is slightly lower than the separate design with the curvature radius increase of the outer and inner wall. When the liner curvature radius is fixed, the shape of MEFP with the integral design is better than the separate design, and the forming velocity of MEFP with the integral design is slightly less than the separate design with the liner center thickness increase. The results show that the forming characteristics of circumferential MEFP of integrated design and separate design have a certain similarity. The shape of MEFP with the integrated design is better than that with separate design, however, the forming velocity of MEFP with the integrated design is slightly lower than that with separate design. © Published under licence by IOP Publishing Ltd.

关键词： Projectiles

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Self-powered wireless impedance sensing for structural health monitoring

Self-powered wireless impedance sensing for structural healt...

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2019 IEEE International Conference on Unmanned Systems, ICUS 2019

作者： Feng, Yue Tang, Xusong Shao, Bohan Han, Yanhui Beijing Institute of Technology Science and Technology on Electromechanical Dynamic Control Laboratory Beijing China Beijing Orient Institute of Measurement Test Beijing China

ISBN: (纸本)9781728137926

Structural damage is often accompanied by equipment failures and safety incidents. For example, aircraft accidents often result from wing breaks and landing gear damage. The self-powered wireless sensing technology is ideal tool for monitoring structural health in multi-locations. In this work, we designed an airflow-driven energy harvester (EH) and integrate into wireless impedance sensing system. Also, the Energy Management and control Circuit (EMC) is designed to provide a stable DC voltage for intermittently driven sensing system. The experimental results show that the self-powered impedance sensing system can operate at every 3 min at a wind speed of 8 m/s. The system error is within 5% compared to the Agilent 4294A (Precision Impedance Analyzer) and the characteristics of the material cracks could be successfully detected and analyzed. © 2019 IEEE.

关键词： Energy harvesting

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Light scattering characteristic from particles located on a surface

Light scattering characteristic from particles located on a ...

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International Conference on Information technology and Computer Application Engineering, ITCAE 2014

作者： Gong, L. Hou, H.L. Zou, J.L. School of Photoelectric Engineering Xi’an Technological University Xi’an China Science and Technology on Electromechanical Dynamic Control Laboratory Xi’an China

ISBN: (纸本)9781138027176

Based on the Finite Difference Time Domain (FDTD) method, the Generalized Perfectly Matched Lays (GPML) can work very well against the half-space problem about the optical surface and defect particles. The connect boundary condition is reduced by the three-wave method. The reciprocity theorem is applied to the near-far field extrapolation. The angle distributions of double particles with different ratios are shown. Some selected calculations on the effects of the shape are described. © 2015 Taylor & Francis Group, London.

关键词： Finite difference time domain method

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Real-time estimation of maneuvering orbit by compensative modeling of "current" acceleration 27

Real-time estimation of maneuvering orbit by compensative mo...

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27th Conference of Spacecraft TT and C technology

作者： Liu, Y. Cao, Jianfeng Liu, Lei Science and Technology on Aerospace Flight Dynamic Laboratory Beijing100094 China Beijing Aerospace Control Center Beijing100094 China

ISBN: (纸本)9783662446867

The unknown maneuver is a key restriction for the real-time spacecraft tracking. For the modeling residual by dynamic of orbits, a compensative modeling method is developed according to the idea of "current" statistic. Then an orbit filter is established based on the new model and the unscented filter. By utilizing a nonmean value and time correlated stochastic process for the maneuvering acceleration, the new model can achieve an online auto-adaptivity for orbit acceleration with different maneuvers mode. Therefore, it can obtain a continuous and accurately estimated orbit for orbit with unknown maneuver. Simulation results for space target with series of random pulsar and continuous maneuvers validated the feasibility and efficiency of the new tracking filter. © Tsinghua University Press, Beijing and Springer-Verlag Berlin Heidelberg 2015.

关键词： Orbits

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Experimental study on permeability evolution of deep high-stressed coal under major horizontal stress unloading paths

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International Journal of Mining science and technology 2024年第11期34卷 1495-1508页

作者： Chao Liu Jiahao Zhang Songwei Wu Jinghua Qi Beichen Yu Liang Wang School of Mechanics and Civil Engineering China University of Mining and TechnologyXuzhou 221116China State Key Laboratory of Mining Disaster Prevention and Control Ministry of EducationShandong University of Science and TechnologyQingdao 266590China School of Safety Engineering China University of Mining and TechnologyXuzhou 221116China State Key Laboratory of Coal Mine Disaster Prevention and Control China University of Mining and TechnologyXuzhou 221116China Key Laboratory of Theory and Technology on Coal and Rock Dynamic Disaster Prevention and Control National Mine Safety AdministrationChina University of Mining and TechnologyXuzhou 221116China

Both bulk stress(σ_(i i))and stress path(SP)significantly affect the transportation characteristics of deep gas during reservoir pressure ***,the experimental study of horizontal stress unloading on seepage behavior of gas-bearing coal under constantσi i-constraints is *** results show that coal permeability is affected by horizontal stress anisotropy(σ_(H)≠σh),and the contribution of minor horizontal stress to permeability is related to the differential response of horizontal *** slippage phenomenon is prominent in deep high-stress regime,especially in low reservoir pressure.σ_(i i)and SP jointly determine the manifestation of slippage effect and the strength of stress sensitivity(γ)of *** reservoir implies an incremental percentage of slip-based permeability,and SP weakens the slippage effect by changing the elastic–plastic state of ***,γis negatively correlated with slippage *** the Walsh model,narrow(low aspect-ratio)fractures within the coal under unloading SP became the main channel for gas seepage,and bring the effective stress coefficient of permeability(χ)less than 1 for both low-stress elastic and high-stress damaged *** the raise of the effective stress,the effect of pore-lined clay particles on permeability was enhanced,inducing an increase inχfor highstress elastic coal.

关键词： True triaxial stress path Constant bulk stress Horizontal stress Effective stress coefficient of permeability Slippage effect

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Design and Test of Missile-Borne Acquisition and Storage System for Magnetoelectric Sensor 3

Design and Test of Missile-Borne Acquisition and Storage Sys...

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3rd International Symposium on Semiconductor and Electronic technology, ISSET 2024

作者： Li, Jiale Zeng, Tao Sui, Li Beijing Institute of Technology Science and Technology on Eletromechanical Dynamic Control Laboratory Beijing100081 China Xi'an Institute of Electromechanical Information Technology Xi'an710065 China

ISBN: (纸本)9798350390285

The magnetoelectric sensor can solve the problem of acceleration sensor signal adhesion when a large aspect ratio warhead penetrates a multi-layer protective structure at high speed to certain extent, but no missile-borne acquisition and storage system suitable for this sensor has been found. Therefore, this paper designed a magnetoelectric sensor missile-borne acquisition and storage system, which used GD32E230K8T6 as the main control chip, used the on-chip SAR-ADC to realize the analog-to-digital conversion, and used a resistor network to realize the in-phase attenuation linear transformation for the signal. The data was stored in a 256Kbit FRAM with a sampling rate of more than 100kHz and a sampling accuracy of 12bit. The test result showed that the prototype accomplished the acquisition task and the storage task, and had power-off protection with 330ms working time after power-off. The prototype can meet the requirements of missile-borne acquisition and storage. © 2024 IEEE.

关键词： Linear transformations

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Neural dynamic Surface Containment control for Multiple Quadrotors

Neural Dynamic Surface Containment Control for Multiple Quad...

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2019 IEEE International Conference on Unmanned Systems, ICUS 2019

作者： Shao, Xingling Tian, Biao Li, Dongguang Ministry of Education North University of China School of Instrument and Electronics North University of China Key Laboratory of Instrumentation Science Dynamic Measurement Taiyuan030051 China Beijing Institute of Technology Science and Technology on Electromechanical Dynamic Control Laboratory Beijing10081 China

ISBN: (纸本)9781728137926

This paper presents an neural dynamic surface containment control design for multiple quadrotors with uncertainties, such that the followers can be driven into the convex hull constituted by multiple dynamic leaders. To facilitate the control design, the quadrotor dynamics is decomposed into translational and rotational subsystems. For each subsystem, in order to enable smooth and rapid learning of unknown system uncertainties and reduce the computational load in traditional neural network (NN), the estimation errors, instead of tracking errors, are used to regulate NN weights and only one NN learning parameter is required for adaptive neural approximation with the aid of minimal learning parameter (MLP), which is more feasible for real-time implementation. Additionally, dynamic surface control (DSC) technique is introduced to extract the time derivative of virtual control laws, and thus the issue of "explosion of complexity" can be circumvented. Finally, the stability analysis is established. Simulation results illustrate the effectiveness and superiority of the proposed control scheme. © 2019 IEEE.

关键词： Real time control

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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 GPS-only navigation and guidance for course-correction fuze

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International Journal of Earth sciences and Engineering 2016年第3期9卷 1314-1318页

作者： Luo, Xiaolin Li, Dongguang Science and Technology on Electormechanical Dynamic Control Laboratory Beijing Institute of Technology Beijing100081 China Mechanic and Electronic Engineering North University of China Tai yuan030051 China

In the military science of ballistics, circular error probable (CEP) is a measure of a weapon system's precision. The problem is how to calculate the CEP included measurement noise, and process noise, a Kalman filter with model replacement, and a simple navigation and control algorithms. Using an augmented state formulation, covariance techniques were used to determine the variances of CEP, The linear covariance analysis proved to be a very useful and fast analysis tool for the preliminary guidance navigation system design and analysis. © 2016 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.

关键词： Global positioning system

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Nonlinear Spline Prioritization Optimization Adaptive Filter

Nonlinear Spline Prioritization Optimization Adaptive Filter

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International Conference on Guidance, Navigation and control, ICGNC 2022

作者： Guo, Wenyan Zhi, Yongfeng Gao, Huan School of Automation Northwestern Polytechnical University Xi’an710129 China Science and Technology on Electromechanical Dynamic Control Laboratory Xi’an710065 China

ISBN: (纸本)9789811966125

The nonlinear spline prioritization optimization adaptive filter (SPOAF) utilized for system identification is proposed to solve the poor steady-state accuracy caused by the mismatched feedback error of the adaptive strategy in spline adaptive filter (SAF). The FIR filter weight is designed to be updated based on the linear error of the linear module. Then, control point is updated according to the error of the whole system. Next, the least mean square algorithm (LMS) and stochastic gradient descent algorithm (SGD) are applied to the nonlinear spline prioritization optimization adaptive filter. Finally, the convergence performance of the proposed SPOAF approach is analyzed. The simulation confirms the effectiveness and efficiency of our proposed SPOAF algorithm. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Adaptive filters

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