基于灰度共生矩阵的微动干扰分类识别

针对雷达成像中面临的调制转发微动干扰、微动散射波干扰、脉冲卷积微动干扰3种新型微动干扰样式的识别问题,提出一种基于灰度共生矩阵的干扰识别方法。该方法从图像域角度出发,首先对雷达接收信号矩阵进行灰度化处理,然后利用灰度共生矩阵提取其纹理参数并构造特征参数,最后采用KNN分类器实现了对雷达接收信号中目标回波和3种微动干扰样式的检测与识别。仿真实验结果表明,当信噪比为-5 dB时,不同干信比下4种信号样式的识别率均能够达到90%以上,每种信号样式整体识别率在98%以上;当信噪比为5 dB时,不同干信比下4种信号样式的识别率均能够达到95%以上,每种信号样式整体识别率在99%以上。     

Infrared super-resolution imaging method based on retina micro-motion

With the wide application of infrared focal plane arrays (IRFPA), military, aerospace, public security and other applications have higher and higher requirements on the spatial resolution of infrared images. However, traditional super-resolution imaging methods have increasingly unable to meet this requirement in technology. In this paper, we adopt the achievement that the human retina micro-motion is the important reason why the human has the hyperacuity ability. Based on the achievement, we bring forward an infrared super-resolution imaging method based on retina micro-motion. In the method, we use the piezoelectric ceramic equipment to control the infrared detector moving variably within a plane parallel to the focal plane. The motion direction is toward each other into a direction of 90°. In the four directions of the movement, we get four sub-images and generate a high spatial resolution infrared image by image interpolation method. In the process of the shifting movement of the detector, we set the threshold of the detector response and record the response time difference when adjacent pixel responses are up to the threshold. By the method, we get the object’s edges, enhance them in the high resolution infrared image and get the super-resolution infrared image. The experimental results show that our proposed super-resolution imaging methods can improve the spatial resolution of the infrared image effectively. The method will offer a new idea for the super-resolution reconstruction of infrared images.     

两类柔性微动直线导轨的刚度特性

分析了两类柔性微动直线导轨的结构特点,提出一种以刚度比指标来综合衡量柔性微动直线导轨导向性能的方法。基于C astig liano(位移)第二定理推导了计算两类柔性微动直线导轨不同方向静刚度的解析表达式。对两类柔性微动直线导轨的设计实例进行分析,结果表明其中一种具有叠形支链的柔性微动直线导轨具有更好的导向性能。该文方法和结论可为柔性微动直线导轨的选型与设计提供参考。     

双曲余弦曲线轮廓柔性关节的设计与分析

基于弹性力学中的应变能理论和卡式第二位移最小定理,推导出了利用双曲余弦曲线轮廓设计的单轴平面微动关节在平面内3个自由度微运动中的柔度解析表达式.在此基础上将各方向柔度变化规律与目前广泛应用于柔性机构设计中的半圆弧曲线平面微动关节的对应规律进行比较,揭示了这种类型微动关节在柔性机构设计中一些有用性能,如不存在变形耦合,且柔度随关节尺寸变化较为稳定.     

基于动态散斑时频特性的合作目标微动参数反演

基于激光动态散斑的时频信号,建立了一套适用于角反射器阵列的微动参数反演算法.首先利用物理光学方法推导了角反射器及角反射器阵列激光散斑的实时强度公式,然后基于短时傅里叶变换研究了散斑功率谱形成机制及其数字特征,最后提出了频谱相关法及时频-相幅变换算法,并采用该方法提取了动态散斑时频谱线周期及振幅分布,反演了三种典型运动状...     

基于瞬时频率率的平动刚体目标微动参数测量

为了估计具有二阶平动的刚体目标的微动参数,提出一种基于短时三次相位函数（CPF）和逆Radon变换（IRT）的参数测量方法.基于典型旋转微动模型,推导并分析初步平动补偿后微动散射中心的瞬时频率率（IFR）;采用短时三次相位函数得到雷达回波的时间瞬时频率率二维平面;基于时间瞬时频率率二维平面,利用逆Radon变换对正弦曲线的测量原理实现平动补偿的速度误差、加速度误差以及微动参数的测量。仿真结果验证了该方法的有效性。      

频率步进信号距离像互相关精确测速算法

针对距离像互相关算法可以实现频率步进信号自测速但测速精度有限这一问题,通过对互相关输出包络和相位的分析,提出了距离像互相关波形分析法和距离像互相关峰值相位法2种测速算法,结合这2种方法提出了一种频率步进信号距离像互相关精确测速算法,该算法的测速精度可以与多普勒测速相比拟,不仅能满足频率步进信号速度补偿的要求,还可以实现微动目标的测量.仿真结果验证了该算法的有效性.     

新型微动工作台的设计与计算

文章设计了一种新型压电式双自由度微位移工作台,提出了一种采用直角双杆机构代替平行四杆机构实现双自由度运动的方法; 基于卡氏第二定理推导了新型工作台在不同方向上的输出刚度解析表达式,在此基础上推导出了工作台的前2阶固有频率;根据得到的输出刚度表达式,定量地分析了柔性铰链参数及连杆长度对工作台输出刚度的影响;同时针对3组不同尺寸参数的工作台,采用有限元法对其进行数值计算,并与理论计算比较,结果表明2种方法计算结果吻合很好,说明了理论模型的正确性.     

面向高精度放大比的微动机构设计与实现

以一种微位移放大模块为研究对象,提出一种以高精度放大比为目标的参数设计方法. 根据伪刚体模型法建立各柔性单元的变形协调关系,利用拉格朗日能量守恒原理推导出系统能量与柔性单元位移的对应关系,在此基础上采用系统能量均布原则使得结构参数关联化,实现了微位移放大模块结构参数的层递式设计. 同时应用有限元ANSYS软件对微位移放大模块进行仿真分析,对比分析表明该理论计算方法与软件仿真结果偏差为6.25%,为面向高精度放大比的微动机构参数设计提供了理论依据.      

Nonuniform stretch processing for the range profile of a target with micro-motion

Complex motions such as micro-motions induce complex range-Doppler coupling effect in radar imaging. Hence, it is a challenge to reconstruct a clear range profile of a target with micro-motion. Stretch processing with fine motion compensation cannot perform well while it ties to eliminate the distortion of range profile caused by Doppler effect, because it is difficult to accurately estimate each scattering center velocity during coherent processing interval. Based on nonuniform stretch processing (NSP), a new technology is proposed to decouple range, time and Doppler and then achieve range profile of target with micro-motion. The new technology uses a new synthetic wide-band waveform and has an innovative mathematic interpretation. Statistical properties of the new approach are primarily examined. Typical models of target with micro-motion for high resolution radar are presented. Monte Carlo simulations demonstrate the performance of the new technology and the simulation results confirm our expectations.