检索结果-内蒙古大学图书馆

10th International Symposium on Test Automation and Instrumentation, ISTAI 2024

作者： Gu, Xibing Su, Zhong Yao, Xiangxian Beijing Key Laboratory of High Dynamic Navigation Technology Beijing Information Science and Technology University Beijing100192 China Key Laboratory of Modern Measurement and Control Technology Ministry of Education Beijing Information Science and Technology University Beijing100192 China

ISBN: (纸本)9781837242672

The precession factor of resonant gyro is the key performance index of gyro sensitive angular velocity, and the main factors affecting the precession factor are the structural parameters of the resonator. In this paper, an all-metal micro-hemispherical resonator with a radius of 3mm is taken as the research object, the expression of the precession factor of the hemispherical resonator is established, and the intrinsic frequencies under different modal orders are obtained through the finite element simulation experimental method, and the influences of the radius of the hemispherical shell, the thickness of the shell, the diameter of the central axis rod, and the radius of the inner fillet angle on the precession factor of the resonator are analyzed. The experimental results show that the size of the inner fillet radius has a significant effect on the precession factor, and the precession factor of the metallic micro-hemispherical resonator is mainly maintained at 0.2980 with a variation range of less than 1%. This study provides reference data for the optimization of the structural parameters of the all-metal micro-hemispherical resonator. © The Institution of Engineering & technology 2024.

关键词： Gyroscopes

来源：评论

学校读者我要写书评

暂无评论

Study on the Monitoring and Analysis Method of the Working Efficiency of Torsional Impactors 29th

Study on the Monitoring and Analysis Method of the Working E...

引用

29th International Conference on Computational and Experimental Engineering and sciences, ICCES 2023

作者： Zhang, Tao Liu, Daixuan Xie, Xue Li, Yumei Beijing Key Laboratory of High Dynamic Navigation Technology Beijing Information Science and Technology University Beijing100101 China Key Laboratory of Modern Measurement and Control Technology Ministry of Education Beijing Information Science and Technology University Beijing100101 China

ISBN: (纸本)9783031425141

The torsional impactor converts the kinetic energy of the drilling fluid into fixed-frequency mechanical circumferential vibration, which can effectively suppress the drilling stick–slip phenomenon and increase the mechanical drilling speed. However, due to various factors such as its performance, formation lithology, and construction parameters such as weight of bit and displacement, it is not possible to effectively monitor and evaluate the working condition and performance of the torsional impactor in the well by relying on surface observation data. In this paper, the torsional impactor is connected to a near-bit measurement tool to form a torsional impactor monitoring system. By experimentally measuring the vibration, rotational speed, bit weight, and torque data of the torsional impactor during operation, the data features are extracted by combining the time domain and frequency domain analysis methods to monitor the operating impact frequency of the torsional impactor and analyze the influence of different drilling parameters on the working efficiency of the torsional impactor. The analysis results show that this study can achieve the monitoring of the working status and working efficiency of the downhole speed lifting tool, which is beneficial to the optimization design of the speed lifting tool and the improvement of the working efficiency. © 2024, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： Condition monitoring

来源：评论

学校读者我要写书评

暂无评论

RSSI-BASED INJECTED GROUND CURRENT FIELD LOCALIZATION STUDY 10

RSSI-BASED INJECTED GROUND CURRENT FIELD LOCALIZATION STUDY

引用

10th International Symposium on Test Automation and Instrumentation, ISTAI 2024

作者： Chu, Sirui Su, Zhong Wang, Yanke Ling, Zhongao Beijing Key Laboratory of High Dynamic Navigation Technology Beijing Information Science and Technology University Beijing100192 China Key Laboratory of Modern Measurement and Control Technology Ministry of Education Beijing Information Science and Technology University Beijing100192 China

ISBN: (纸本)9781837242672

Aiming at the problem that traditional positioning techniques are easily limited in complex environments, this study proposes a positioning method based on Received Signal Strength Indication (RSSI) of injected ground current field, which is suitable for closed or sheltered environments, such as underground alleyways, and also works effectively under extreme conditions, such as alleyways collapsing. Firstly, the validity of the ground current field signals is tested to ensure that the signals are reliable;secondly, the extracted signals are screened to remove signals with low signal-to-noise ratios and high ground resistance, and to reduce the influence of environmental noise on the localization results;next, the RF parameter A as well as the signal transmission constant n are computed using the linear regression least square method, which provide important fitting parameters for the subsequent establishment of the RSSI localization model;finally, a Gaussian filtering to process the RSSI data collected by modelling. The experimental results show that the method achieves the positioning of underground alleyways environment with good feasibility and effectiveness, and provides a feasible solution for carrying out efficient alleyway personnel positioning and rescue operations, which has important theoretical significance and practical value. © The Institution of Engineering & technology 2024.

关键词： Linear regression

来源：评论

学校读者我要写书评

暂无评论

A Spatial Modes Filtering FETD Method for 3-D Periodic Structures

引用

Applied Computational Electromagnetics Society Journal 2025年第2期40卷 96-102页

作者： Wang, Yixin Wei, Bing Fan, Kaihang He, Xinbo Zhao, Sihan Department of Information Technology Shaanxi Police College Xi’an710021 China School of Physics Xidian University Xi’an710071 China School of Information and Communications Engineering Xi’an Jiaotong University Xi’an710049 China Science and Technology on Electromechanical Dynamic Control Laboratory Xi’an710065 China

– A spatial modes filtering (SMF) finite-element time-domain (FETD) method with periodic boundary condition (PBC) is proposed for efficiently analyzing the electromagnetic characteristics of 3-D periodic structures with partial fine structures. The system matrices of FETD become asymmetrical because of the introduction of PBC, which prevents the system eigenvalue analysis. By decomposing the system matrix into PBC-independent and PBC-related parts, the unstable spatial modes under the given large time step can be found and removed from the symmetrical PBC-independent system matrices. Then the system matrix equation and time marching of the SMF-FETD and SMF-FETD method based on local eigenvalue solution (LES-SMF-FETD) with PBC are obtained. Numerical results illustrate the efficiency and effectiveness of the SMF-FETD method with PBC based on non-uniform mesh for analyzing the transport properties of 3-D periodic structures. © ACES.

关键词： Eigenvalues and eigenfunctions

来源：评论

学校读者我要写书评

暂无评论

Anti-jamming Method of Radio Fuze Based on KNN 4

Anti-jamming Method of Radio Fuze Based on KNN

引用

4th International Conference on Intelligent control, Measurement and Signal Processing, ICMSP 2022

作者： Liu, Bing Hao, Xinhong Yang, Jin Science and Technology on Electromechanical Dynamic Control Laboratory Beijing Institute of Technology Beijing China

ISBN: (数字)9781665486583

ISBN: (纸本)9781665486583

In order to improve the anti-jamming ability of radio fuze and maximize the effectiveness of radio fuze in complex electronmagnetic environments, it is necessary to distinguish targets and jamming signals effectively. This research takes a sample of FM radio fuze as an example, mainly considers the sine amplitude modulation frequency-sweeping (Sine-AM) jamming signal and noise amplitude modulation frequency-sweeping (Noise-AM) jamming signal, which are pose the greatest threat to the FM radio fuze. The frequency exponential entropy and norm entropy of the fuze output signal are extracted. Then these features are input to K nearest neighbors classifier, in this way, the target signals and jamming signals can be effectively distinguished, Further improved the FM radio fuze ability to anti-jamming signal. The expermient result shows that using KNN classifier can get a classification accuracy more than 99%. © 2022 IEEE.

关键词： Amplitude modulation

来源：评论

学校读者我要写书评

暂无评论

Design and experimental study of a novel piezoelectric accelerometer 4

Design and experimental study of a novel piezoelectric accel...

引用

4th International Conference on Sensors and Information technology, ICSI 2024

作者： Zou, Qipeng Sui, Li Zhang, Meiyun Zhang, Li Science and Technology on Electromechanical Dynamic Control Laboratory Beijing Institute of Technology Beijing100081 China Northwest Industries Group Co. Ltd. Xi'an710043 China

ISBN: (数字)9781510678699

ISBN: (纸本)9781510678682

The collision or penetration overload signal measured by the general accelerometer may encounter problems such as signal overlap and multi-layer signal adhesion. This paper designs a novel piezoelectric accelerometer with the characteristics of mechanical filtering and switching. The structure and working principle of this accelerometer are described in the paper, and its output characteristics are obtained through experiments. The experimental results show that the output signal of the new piezoelectric accelerometer has the characteristics of less high-frequency interference signal and no signal adhesion, which are conducive to the information extraction of collision and penetration multi-layer target by the flying carrier. © 2024 SPIE.

关键词： Accelerometers

来源：评论

学校读者我要写书评

暂无评论

Blind frequency estimation of pseudo-code phase and linear frequency modulation composited fuze by Duffing oscillator 55

Blind frequency estimation of pseudo-code phase and linear f...

引用

55th International Conference on Vibroengineering

作者： Guan, Enming Yan, Xiaopeng Lv, Minghui Wan, Yi Chen, Yanjun Science and Technology on Electromechanical Dynamic Control Laboratory Beijing Institute of Technology Beijing China

In order to blind estimate pseudo-code (PN) code phase modulation and linear frequency modulation composited fuzecarrier frequency. By improving the traditional Duffing oscillator detection model of strong reference signal, an approximate carrier frequency blind estimation method by small-scale periodic Duffing oscillator is proposed in this paper. In this method, the internal dynamic frequency is used to approximate the changes of the output time domain and phase diagram of the chaotic system during the frequency to be measured. Then calculate the different frequency to blind estimate the carrier frequency of the signal. This method widens the range of frequency detection and can realize blind frequency estimation with less prior knowledge. The parameter estimation effect of the approximate carrier frequency estimation method based on small cycle Duffing oscillator under different signal to noise ration (SNR) is simulated and analyzed in this paper. The results show that this method has better parameter estimation performance than the traditional composited fuze frequency estimation method, especially in the environment of low SNR. © 2022 JVE International. All rights reserved.

关键词： Frequency estimation

来源：评论

学校读者我要写书评

暂无评论

LIGHTWEIGHT MARS SURFACE DETECTION ALGORITHM BASED ON IMPROVED YOLOV7 10

LIGHTWEIGHT MARS SURFACE DETECTION ALGORITHM BASED ON IMPROV...

引用

10th International Symposium on Test Automation and Instrumentation, ISTAI 2024

作者： Liu, Jingwei Dai, Juan Tian, Kaiyuan Sun, Kedong Beijing Key Laboratory of High Dynamic Navigation Technology Beijing Information Science & Technology University Beijing China Key Laboratory of Modern Measurement and Control Technology Ministry of Education Beijing China School of Automation Beijing Information Science & Technology University Beijing China

ISBN: (纸本)9781837242672

Mars surface detection is a challenging task that takes into account environmental factors such as terrain complexity, ground flatness, rock distribution, geological features, and storms. In this paper, we address the complexity of rock distribution on the surface of Mars and the resource-constrained difficulties of intelligences in performing the task, and propose the Yolov7-MFGC model on top of Yolov7, which solves the problems of existing rock detection models in terms of large computational load and number of parameters, as well as resource constraints in a specific environment. In this paper, we use a homemade Mars surface rock dataset for training and testing, and the test results show that Yolov7-MFGC improves the accuracy by 1.7%, reduces the amount of parameters by 49%, shrinks the model volume by 49.6%, and reduces the GFLOPS by 70% compared with Yolov7. Therefore, it can be concluded that Yolov7-MFGC is able to better perform the Mars surface rock detection task. © The Institution of Engineering & technology 2024.

关键词： Martian surface analysis

来源：评论

学校读者我要写书评

暂无评论

A Multi-Layer Frequency Selective Surface with Broad Bandpass and High Selectivity

A Multi-Layer Frequency Selective Surface with Broad Bandpas...

引用

2024 IEEE International Conference on Computational Electromagnetics, ICCEM 2024

作者： Gao, Ruicheng Wen, Shuai Mao, Yongyan Bi, Lige School of Electronic Engineering Xidian University Xian China Science and Technology On Electromechanical Dynamic Control Laboratory China Electronic Engineering Research Institute Xian China

ISBN: (纸本)9798350383317

A novel broadband bandpass Frequency Selective Surface (FSS) is designed with the intention of surpassing the performance of previous designs. Through the utilization of cascading multilayers of capacitive patches and inductive grids, this design achieves our goal of wide bandwidth as well as high selectivity, while maintaining an acceptable thickness. The stimulated results exhibit a broad passband width, ranging from 12.5 GHz to 18.2 GHz, as well as steep out-of-band attenuation with a transitional zone of less than 1 GHz. © 2024 IEEE.

关键词： Frequency selective surfaces

来源：评论

学校读者我要写书评

暂无评论

Blind parameter estimation of pseudo-random binary code-linear frequency modulation signal based on Duffing oscillator at low SNR

引用

Chinese Physics B 2021年第5期30卷 312-319页

作者： Ke Wang Xiaopeng Yan† Ze Li Xinhong Hao Honghai Yu Science and Technology on Electromechanical Dynamic Control Laboratory School of Mechatronical EngineeringBeijing Institute of TechnologyBeijing 100081China

Conventional parameter estimation methods for pseudo-random binary code-linear frequency modulation(PRBC-LFM)signals require prior knowledge,are computationally complex,and exhibit poor performance at low signal-to-noise ratios(SNRs).To overcome these problems,a blind parameter estimation method based on a Duffing oscillator array is proposed.A new relationship formula among the state of the Duffing oscillator,the pseudo-random sequence of the PRBC-LFM signal,and the frequency difference between the PRBC-LFM signal and the periodic driving force signal of the Duffing oscillator is derived,providing the theoretical basis for blind parameter *** based on amplitude method,short-time Fourier transform method,and power spectrum entropy method are used to binarize the output of the Duffing oscillator array,and their performance is *** pseudo-random sequence is estimated using Duffing oscillator array synchronization,and the carrier frequency parameters are obtained by the relational expressions and characteristics of the difference *** results show that this blind estimation method overcomes limitations in prior knowledge and maintains good parameter estimation performance up to an SNR of-35 dB.

关键词： Duffing oscillator pseudo-random binary code-linear frequency modulation(PRBC-LFM)signal blind parameter estimation low signal-to-noise ratio(SNR)

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：