检索结果-南通市图书馆

A camouflage target detection method based on local minimum difference constraints

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2023年第3期34卷 696-705页

作者： GAN Yuanying liu chuntong LI Hongcai liu Zhongye School of Missile Engineering Rocket Force University of EngineeringXi’an 710025China

To address the problems of missing inside and incomplete edge contours in camouflaged target detection results,we propose a camouflaged moving target detection algorithm based on local minimum difference constraints(LMDC).The algorithm first uses the mean to optimize the initial background model,removes the stable background region by global comparison,and extracts the edge point set in the potential target region so that each boundary point(seed)grows along the center of the ***,we define the minor difference constraints term,combine the seed path and the target space consistency,and calculate the attributes of each pixel in the potential target area to realize camouflaged moving target *** algorithm of this paper is verified based on a public data sofa video and test videos and compared with the five classic *** experimental results show that the proposed algorithm yields good results based on integrity,accuracy,and a number of objective evaluation indexes,and its overall performance is better than that of the compared algorithms.

关键词： camouflage target detection moving target local contrast

Optical Fiber Grating Vibration Sensor for Vibration Monitoring of Hydraulic Pump

在线全文

学校读者我要写书评

暂无评论

Photonic Sensors 2017年第2期7卷 140-147页

作者： Zhengyi ZHANG chuntong liu Hongcai LI Zhenxin HE Xiaofeng ZHAO Department Two Rocket Force University of Engineering Xi'an 710025 China

In view of the existing electrical vibration monitoring traditional hydraulic pump vibration sensor, the high false alarm rate is susceptible to electromagnetic interference and is not easy to achieve long-term reliable monitoring, based on the design of a beam of the uniform strength structure of the fiber Bragg grating （FBG） vibration sensor. In this paper, based on the analysis of the vibration theory of the equal strength beam, the principle of FBG vibration tuning based on the equal intensity beam is derived. According to the practical application of the project, the structural dimensions of the equal strength beam are determined, and the optimization design of the vibrator is carried out. The finite element analysis of the sensor is carried out by ANSYS, and the first order resonant frequency is 94.739 Hz. The vibration test of the sensor is carried out by using the vibration frequency of 35 Hz and the vibration source of 50 Hz. The time domain and frequency domain analysis results of test data show that the sensor has good dynamic response characteristics, which can realize the accurate monitoring of the vibration frequency and meet the special requirements of vibration monitoring of hydraulic pump under specific environment.

关键词： Fiber Bragg grating uniform strength beam vibrating monitoring vibration sensor

Fiber Optic Gyroscope Dynamic North-Finder Algorithm Modeling and Analysis Based on Simulink

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Photonic Sensors 2017年第3期7卷 283-288页

作者： Zhengyi ZHANG chuntong liu Department Two Rocket Force University of Engineering Xi'an 710025 China

In view of the problems such as the lower automation level and the insufficient precision of the traditional fiber optic gyroscope （FOG） static north-finder, this paper focuses on the in-depth analysis of the FOG dynamic north-finder principle and algorithm. The simulation model of the FOG dynamic north found algorithm with the least square method by points is established using Simulink toolbox, and then the platform rotation speed and sampling frequency, which affect FOG dynamic north found precision obviously, are simulated and calculated, and the optimization analysis is carried out as a key consideration. The simulation results show that, when the platform rotation speed is between 4.5°/s and 8.5°/s and the sampling frequency is at about 50Hz in the case of using the parameters of this paper, the FOG dynamic north finding system can reach the higher precision. And the conclusions can provide the reference and validation for the engineering and practical of FOG dynamic north-finder.

关键词： Fiber optics optical fiber gyroscope dynamic north found modeling

Design of Vibration Sensor Based on Fiber Bragg Grating

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Photonic Sensors 2017年第4期7卷 345-349页

作者： Zhengyi ZHANG chuntong liu Department Two Rocket Force University of Engineering Xi'an 710025 China

Fiber grating is a kind of new type of fiber optic light source device which has been rapidly changing in the refractive index of the core in recent years. Especially, it can realize the high precision of the external parameters by means of the special structure design and the encapsulation technology [1, 2]. In this paper, a fiber grating vibration sensor which is suitable for vibration monitoring in key areas is designed based on the technical background of vibration monitoring system. The sensor uses a single beam structure and pastes the fiber Bragg grating （FBG） to measure the vibration wavelength on the surface. When the vibration is simply harmonic vibration, the Bragg reflection wavelength will change periodically, and the periodic variation of the wavelength curve can be measured by the fiber grating demodulator, then the correctness of the experimental results is verified. In this paper, through the analysis of the data measured by the demodulator, the MATLAB software is used to verify the data, and the different frequency domains, the modes, and the phase frequency curves are obtained. The measurement range is 0Hz-100Hz, and the natural frequency is 90.6Hz.

关键词： Vibration monitoring fiber Bragg grating vibration sensor modal analysis frequency domain

Research on One-Piece Structure Target Flow Sensing Technology Based on Fiber Bragg Grating

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Photonic Sensors 2016年第4期6卷 303-311页

作者： chuntong liu Zhengyi ZHANG Hongcai LI Zhenxin HE Xiaofeng ZHAO Rongjing WU Department Two Rocket Force University of Engineering Xi 'an 710025 China

In view of problems existing in the detection of the traditional hydraulic system, such as the large volume of sensor and the low measurement accuracy, a new one-piece target type flow sensor is designed and researched based on fiber Bragg grating （FBG）. A compact structure is designed, which is convenient to be dismantled, processed, and installed, based on the analysis of the principle of FBG and the structure of target type flow sensor. The force of target put in fluid flow is turned into the FBG wavelength drift, with a corresponding relationship. The problem on the cross sensitivities of the temperature and strain is solved effectively by using double FBG symmetrically pasted on the both surfaces of the cantilever. The impact on the fluid state is analyzed through simulation in the software FLUENT, and the results show that the impact was smaller than that of the traditional structure. The results of experiments in the hydraulic system show that there is a good linear relationship between the change in the dual FBG central wavelength and mass loading on the target sheet has a good linear relationship, and the sensitivity is twice that of a single FBG sensitivity.

关键词： Fiber Bragg grating flow sensor target type structure equal intensity cantilever beam

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

基于三维注意力与混合卷积的高光谱图像分类

系统工程与电子技术 2023年第9期45卷 2673-2680页

作者：赵晓枫牛家辉刘春桐夏玉婷火箭军工程大学导弹工程学院陕西西安710025 兵器发射理论与技术国家重点学科实验室陕西西安710025

针对现有高光谱图像分类模型在特征提取的过程中有效特征关注缺乏的问题,提出了一种基于三维卷积注意力与混合卷积的高光谱图像分类方法。该方法使用三维卷积和二维卷积串联完成对高光谱图像空谱特征的提取,并在三维卷积阶段引入注意力... 详细信息

针对现有高光谱图像分类模型在特征提取的过程中有效特征关注缺乏的问题,提出了一种基于三维卷积注意力与混合卷积的高光谱图像分类方法。该方法使用三维卷积和二维卷积串联完成对高光谱图像空谱特征的提取,并在三维卷积阶段引入注意力机制,使得模型在提取底层空谱特征的同时实现对有效特征的关注和激活。相对于传统三维卷积模型,提出的分类模型减小了运算复杂度,提升了模型噪声抑制能力,提高了分类效果。针对该方法的消融实验证明了提出的三维卷积注意力机制的有效性,在印第安松树林和帕维亚大学两个公开数据集上与其他5种分类模型的对比实验中取得了最优的分类精度。

关键词：高光谱图像分类三维注意力机制混合卷积空谱特征提取

基于Simulink的光纤陀螺动态寻北算法建模及分析

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

红外与激光工程 2018年第S1期47卷 86-91页

作者：李洪才刘春桐赵晓枫马世欣火箭军工程大学陕西西安710025

针对传统光纤陀螺静态寻北方案中存在的自动化程度较低、精度不高等不足，对光纤陀螺动态寻北的原理及算法进行了深入分析，利用MATLAB软件中的Simulink仿真工具箱建立了光纤陀螺逐点最小二乘拟合动态寻北算法的仿真模型，并重点针对影... 详细信息

针对传统光纤陀螺静态寻北方案中存在的自动化程度较低、精度不高等不足，对光纤陀螺动态寻北的原理及算法进行了深入分析，利用MATLAB软件中的Simulink仿真工具箱建立了光纤陀螺逐点最小二乘拟合动态寻北算法的仿真模型，并重点针对影响光纤陀螺动态寻北精度的平台转速和采样频率进行了仿真计算和优化分析。仿真及计算结果表明，在采用文中提出参数的情况下，当旋转平台的转速约位于4．5-8．5（°）／s之间，采样频率为50Hz左右时，光纤陀螺动态寻北系统可以得到较高的寻北精度。论文所建立的模型结构及研究结论可以为光纤陀螺动态寻北系统的设计提供理论参考，同时对于光纤陀螺动态寻北技术的理论研究及具体实现也具有借鉴意义。

关键词：光纤陀螺动态寻北 Simulink 算法建模

在线全文

学校读者我要写书评

暂无评论

基于背景判别与邻域补偿的高光谱异常检测

仪器仪表学报 2019年第3期40卷 239-245页

作者：马世欣刘春桐王欣甘源滢张正义火箭军工程大学导弹工程学院西安710025 高新技术研究所青州262550

为克服高光谱局部异常检测算子背景虚警严重,探测效果不佳等问题,提出了基于核光谱角背景判别与邻域补偿的异常检测算法。算法从背景像元的筛选和探测结果的补偿两个角度提高像元探测精度,在背景像元的处理方面,提出了一种基于核光谱角... 详细信息

为克服高光谱局部异常检测算子背景虚警严重,探测效果不佳等问题,提出了基于核光谱角背景判别与邻域补偿的异常检测算法。算法从背景像元的筛选和探测结果的补偿两个角度提高像元探测精度,在背景像元的处理方面,提出了一种基于核光谱角距离相似度的背景像元筛选算法,将光谱分辨性能更强的核光谱角引入背景差异性判别过程,准确可靠地实现局部背景像元的筛选和优化;同时,针对异常检测算子探测精度不高等问题,引入邻域加权的空谱联合补偿机制,并提出基于核光谱角距离相似度的动态模板卷积补偿算法,显著增强了背景与目标的可分性。在与RX、LRX、KRX和CRD等异常检测算法的对比中发现,该算法表现出较强的探测性能,在抑制虚警和提高探测精度等方面达到了不错的效果。

关键词：高光谱图像异常目标检测核光谱角背景筛选邻域补偿

溶胶晶种法合成纳米高硅Beta分子筛及其对挥发性有机物的吸附特性

在线全文

学校读者我要写书评

暂无评论

化学反应工程与工艺 2022年第3期38卷 201-209页

作者：刘春彤赵晓慧陈海军南开大学电子信息与光学工程学院天津300350 中芯国际集成电路制造(天津)有限公司天津300385

高硅Beta分子筛具有孔径较大、疏水性能好的性能,可用来吸附大气中的挥发性有机物,但如何在无氟体系下合成高硅Beta分子筛仍是一项技术难题。通过添加分子筛前驱体溶胶作为晶种,采用传统的水热合成法在无氟体系中合成了纳米级的高硅Bet... 详细信息

高硅Beta分子筛具有孔径较大、疏水性能好的性能,可用来吸附大气中的挥发性有机物,但如何在无氟体系下合成高硅Beta分子筛仍是一项技术难题。通过添加分子筛前驱体溶胶作为晶种,采用传统的水热合成法在无氟体系中合成了纳米级的高硅Beta分子筛。研究发现:所合成的高硅Beta分子筛具有结晶性良好、比表面积高以及形貌规则均匀等特点;在合成过程中前驱体溶胶所生成的Beta分子筛发生溶解转化,诱导了高硅Beta分子筛的结晶。这种方法所合成的高硅Beta分子筛具有较好的疏水性以及良好的吸附挥发性有机物(VOCs)的性能。

关键词：高硅Beta分子筛晶种溶胶挥发性有机物吸附疏水性