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31st International Symposium on Ballistics, BALLISTICS 2019

作者： Zhang, Zhibiao Meng, Cheng Wang, Yushi Science and Technology on Electromechanical Dynamic Control Laboratory China School of Mechanical Engineering Nanjing University of Science and Technology Jiangsu Nanjing210094 China

ISBN: (纸本)9781605956107

The fabrication error and assembly error of warhead and fuse will cause the dynamicunbalance of howitzer projectile, which will bring a negative impact on the safety andreliability of fuse. In order to obtain the motion of a certain 155 mm howitzer projectile onthe exterior ballistics, the six-dimensional rigid body motion equations of the projectile werestudied. The aerodynamic parameters which needed for the six-dimensional rigid bodymotion equations of the projectile's exterior ballistics need to be obtained by ***, the credibility of the simulation method is verified in this paper. Then theaerodynamic parameters of the projectile are obtained by numerical simulation of theprojectile flow field. When solving the six-dimensional rigid body motion equations ofprojectile exterior ballistics, the dynamic unbalance of projectile is considered. Thecalculation results are very important for the safety and reliability of fuze on the projectileunder the condition of dynamic unbalance. © 2019 by International Ballistics Society All rights reserved.

关键词： Projectiles

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A C-Band Reconfigurable Pixel Antenna for Anti-Jamming Fuze

A C-Band Reconfigurable Pixel Antenna for Anti-Jamming Fuze

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International Conference on Microwave and Millimeter Wave technology Proceedings

作者： Yiming Wang Wentao Li Xiaowei Shi Science and Technology on Electromechanical Dynamic Control Laboratory China School of Electronic Engineering Xidian University Xi’an China

ISBN: (数字)9781728157337

ISBN: (纸本)9781728157344

Radio fuze devices are used to detect the location of targets on the battlefield. With the continuous development of electronic technology, their ability to resist external interference has received increasing attention. In this letter, a reconfigurable pixel antenna working in the C-band is proposed. The antenna consists of a driving patch and a parasitic pixel surface that is divided into two layers, the inner and outer layers. By changing the connection of the inner and outer pixel surfaces, the antenna's operating frequency, polarization, and radiation pattern can be controlled in real time, the reconfigurable performance of two frequency and polarization states and three pattern modes for each operating state are obtained. Both operating states are in the C-band, and the antenna gain is about 5dB and 4dB, respectively. This antenna can be used in anti-jamming fuze. Compared with the traditional microstrip fuze antenna, the designed antenna is suitable for more working scenarios, and the flexible reconfigurable performance is more conducive to the realization of anti-jamming performance.

关键词： Microwave antennas Time-frequency analysis Microstrip antennas Resists Real-time systems Frequency control Antenna radiation patterns

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Experimental Study on Adsorption-Deformation-Seepage of Co2, Ch4, and N2 in Anthracite

SSRN

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SSRN 2022年

作者： Jia, Jinzhang Wu, Yumo Zhao, Dan Li, Bin Wang, Dongming College of Safety Science and Engineering Liaoning Technical University Liaoning Fuxin123000 China Key Laboratory of Thermal Dynamic Disaster Prevention and Control of Ministry of Education Liaoning Technical University Liaoning Huludao125105 China Faculty of Civil Engineering and Architecture Zhanjiang University of Science and Technology Guangdong Zhanjiang524000 China School of Environmental and Chemical Engineering Shenyang Ligong University Shenyang110159 China

The adsorption capacity, deformation, and permeability of coal are the key factors that affect coalbed methane yield and CO 2 geological storage. To explore the adsorption-deformation-seepage mechanism of coal, this paper takes anthracite as the research object and uses the coal rock adsorption-deformation-seepage test platform under multi-physical field conditions to conduct an adsorption-deformation-seepage experimental study of columnar anthracite through the adsorption of CO 2 , CH 4 , and N 2 under stress. The results showed that the adsorption capacity and deformation of anthracite for CO 2 gas were the largest, followed by CH 4 and N 2 . An increase in the adsorption pressure showed an initial decrease and then increase in the permeability of anthracite. The critical pressure points of CO 2 /CH 4 /N 2 gas permeabilities in anthracite were about 2.0 MPa, 1.75 MPa, and 1.5 MPa, respectively. N 2 showed the greatest permeability, followed by CH 4 and CO 2 . Improvements in the dynamic prediction models of adsorption capacity, coal deformation, and permeability based on the law of adsorption-deformation-seepage of coal were established. © 2022, The Authors. All rights reserved.

关键词： Carbon dioxide

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Modeling and Analysis of a Non-linear Electret Electrostatic Energy Harvester

Modeling and Analysis of a Non-linear Electret Electrostatic...

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IEEE International Conference on Automation, Electronics and Electrical Engineering (AUTEEE)

作者： Shaohua Niu Chunhui Gao Jian Chen Science and Technology on Electromechanical Dynamic Control Laboratory Beijing Institute of Technology Beijing China Beijing Power Machinery Institute Beijing China

ISBN: (数字)9781728198279

ISBN: (纸本)9781728181585

With the rapid development of MEMS and CMOS sensors and improvement of data processing capabilities we have entered the era of the internet of everything (IoE), and the ensuing problem of sensor power supply has attracted more and more people's attention. Vibration energy harvester that can directly convert vibration energy into electrical energy from the environment have become hot topics in recent years because of the short life, large size, long-term storage and other shortcomings of traditional chemical batteries. The electrostatic vibration energy harvester is a typical harvester, which always uses beam structure to capture the environmental energy. However the working bandwidth of traditional beam is always relatively narrow, while the vibration frequency range of environment is relatively wide. Thus the capture energy efficiency of traditional beam structure is relatively low. In this paper, a nonlinear method is introduced into electret electrostatic energy harvester, which employed magnetic body structure to introduce nonlinear force. In the paper, the model of this nonlinear harvest is built, and its characteristics are analyzed. According the analysis result, magnetic force introduced can improve capture energy bandwidth, moreover, repulsive force expands the bandwidth larger than attractive force.

关键词： Vibrations Force Electrets Magnetic forces Magnetic resonance Magnetoelasticity Electrostatics

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Adsorption of Ch4/Co2/N2 by Different Functional Groups in Coal

SSRN

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SSRN 2022年

To explore the microscopic mechanism of gas adsorption by different functional groups in coal and provide theoretical support for the prevention and control of coal mine gas disasters, a slit-pore model and fragment model modified by different functional groups were built using Materials Studio software, based on density functional theory and the Monte Carlo method. The adsorption characteristics of seven different functional group models on the gas were analyzed, and the microscopic mechanism of adsorption performance of different functional groups on CH 4 /CO 2 /N 2 was revealed. The results showed that the order of the electrophilic ability of each functional group fragment followed benzene ring >‒OH>‒C=O>‒O‒CH 3 >‒COOH>‒CH 3 >‒CH 2 ‒CH 3 , and the order of nucleophilic ability was benzene ring >‒CH 2 ‒CH 3 >‒CH 3 >‒COOH>‒OH>‒C=O>‒O‒CH 3 . After adding different functional groups to the surface of the complete activated carbon, the electrophilic ability and nucleophilic ability decreased. The adsorption heat was not only affected by the adsorption amount but also by the non-uniformity of the adsorbent surface. The oxygen-containing functional groups were beneficial to the adsorption of CO 2 gas, and the aliphatic functional groups were committed to the adsorption of CH 4 and N 2 . © 2022, The Authors. All rights reserved.

关键词： Coal

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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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Analysis on Stability of Three-loop Autopilot with An Acceleration Feedback Augmentation Loop

Analysis on Stability of Three-loop Autopilot with An Accele...

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第40届中国控制会议

作者： Hui Wang Tao Li Daoguang Tang Junfang Fan Yifang Yuan Luyao Zang Wugang Wang Chunyan Xiao School of Aerospace Engineering Beijing Institute of Technology Beijing Key Laboratory of UAV Autonomous Control Beijing Institute of Technology School of Electrical and Control Engineering North University of China Beijing Key Laboratory of High-Dynamic Navigation Technology Beijing Information Science and Technology University China PLA 63961 Unit Beijing System Design Institute of Electro-Mechanic Engineering Northwest Industries Group CO. Ltd.

In order to construct a stable augmentation loop, a novel three-loop autopilot structure with an acceleration feedback is proposed. Based on LQR and analytical methods, the design process of the controller parameters is deduced. For a static unstable missile, the control characteristics of a three-loop autopilot with acceleration feedback are compared with classical three-loop and pseudo-angle-of-attack feedback three-loop autopilots. It is pointed out that the closed-loop gain of the three-loop autopilot with acceleration signal feedback is 1, which is not affected by the control parameters. The autopilot can control the static unstable missile, and the acceleration signal is easier to obtain than the pseudo-angle-of-attack.

关键词： Acceleration feedback Stable augmentation loop Autopilot Static unstable missile

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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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Weak wide-band signal detection method based on small-scale periodic state of Duffing oscillator

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Chinese Physics B 2018年第3期27卷 205-215页

作者： Jian Hou Xiao-peng Yan Ping Li Xin-hong Hao Science and Technology on Electromechanical Dynamic Control Laboratory School of Mechatronical Engineering Beijing Institute of Technology Beijing 100081 China

The conventional Duffing oscillator weak signal detection method, which is based on a strong reference signal, has inherent deficiencies. To address these issues, the characteristics of the Duffing oscillator＇s phase trajectory in a small- scale periodic state are analyzed by introducing the theory of stopping oscillation system. Based on this approach, a novel Duffing oscillator weak wide-band signal detection method is proposed. In this novel method, the reference signal is discarded, and the to-be-detected signal is directly used as a driving force. By calculating the cosine function of a phase space angle, a single Duffing oscillator can be used for weak wide-band signal detection instead of an array of uncoupled Duffing oscillators. Simulation results indicate that, compared with the conventional Duffing oscillator detection method, this approach performs better in frequency detection intervals, and reduces the signal-to-noise ratio detection threshold, while improving the real-time performance of the system.

关键词： Duffing oscillator weak signal detection stopping oscillation system small-scale periodic state

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State Estimation for Linear Systems with Quadratic Outputs

arXiv

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arXiv 2023年

作者： Berkane, Soulaimane Theodosis, Dionysis Hamel, Tarek Dimarogonas, Dimos V. Département d’informatique et d’ingénierie Université du Québec en Outaouis GatineauQC Canada theDepartment of Electrical Engineering Lakehead University ON Canada the Dynamic Systems and Simulation Laboratory Technical University of Crete Greece the Divi-sion of Decision and Control Systems School of Electrical Engineering and Computer Science KTH Royal Institute of Technology Sweden I3S-CNRS University Côte d’Azur Institut universitaire de France France

This letter deals with the problem of state estimation for a class of systems involving linear dynamics with multiple quadratic output measurements. We propose a systematic approach to immerse the original system into a linear time-varying (LTV) system of a higher dimension. The methodology extends the original system by incorporating a minimum number of auxiliary states, ensuring that the resulting extended system exhibits both linear dynamics and linear output. Consequently, any Kalman-type observer can showcase global state estimation, provided the system is uniformly observable. © 2023, CC BY.

关键词： Time varying systems

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