用自校正的方法提高SiO_2的测量精度

介绍了一种自校正方法 ,能够在自动分析 Si O2 —二氧化硅浓度的过程中 ,自动校正参数 ,克服了环境温度对硅光电池的影响 ,从而提高了测量精度     

A self-calibration algorithm for cross array in the presence of mutual coupling

In this paper,a novel blind mutual coupling self-calibration algorithm especially tailored to cross array is proposed.This method compensates for the mutual coupling not only between sensors in each subarray but also between two subarrays.Exploiting the property of coupling matrix,the proposed method requires neither the calibration sources in known locations nor the multidimensional nonlinear search.This method can jointly estimate the DOAs of the incoming signals and the unknown mutual coupling coefficien...     

多波束天线通道幅相误差的自校正算法

多波束天线利用多信号分类(MUSIC)算法对目标参数进行精确估计时,存在多波束天线的通道幅度和相位误差的失配现象,使MUSIC算法的性能严重下降;针对基于MUSIC的数字波束通道不一致问题,给出了一种新的基于MUSIC算法的最小化代价函数的波束无源自校正算法,利用阵列结构的先验知识对接收数据进行预处理,得到校正矩阵后自校正,并根据多波束阵列天线形成网络天线实测参数,加入随机幅度和相位误差进行计算机模拟仿真,验证仿真算法的正确性。     

WSNS中基于箱线图的误差自校正定位算法

针对基于接收信号强度指示(RSSI)的无线传感器网络(WSNs)节点定位技术易受环境影响、算法运算量大等问题,提出一种基于箱线图的误差自校正定位算法.该算法采用箱线图法处理测距过程中的异常RSSI值,利用自校正最小二乘法消除测距误差进而实现节点定位.仿真和实验结果表明,该算法可以有效抑制异常RSSI值,显著提高节点定位的准确性和稳定性,而且无需建立复杂的数据传播模型或构造RSSI位置指纹分布图.     

Self-calibration of stationary non-rotating zooming cameras

This paper proposes a new method for self-calibrating a set of stationary non-rotating zooming cameras. This is a realistic configuration, usually encountered in surveillance systems, in which each zooming camera is physically attached to a static structure (wall, ceiling, robot, or tripod). In particular, a linear, yet effective method to recover the affine structure of the observed scene from two or more such stationary zooming cameras is presented. The proposed method solely relies on point correspondences across images and no knowledge about the scene is required. Our method exploits the mostly translational displacement of the so-called principal plane of each zooming camera to estimate the location of the plane at infinity. The principal plane of a camera, at any given setting of its zoom, is encoded in its corresponding perspective projection matrix from which it can be easily extracted. As a displacement of the principal plane of a camera under the effect of zooming allows the identification of a pair of parallel planes, each zooming camera can be used to locate a line on the plane at infinity. Hence, two or more such zooming cameras in general positions allow the obtainment of an estimate of the plane at infinity making it possible, under the assumption of zero-skew and/or known aspect ratio, to linearly calculate the camera's parameters. Finally, the parameters of the camera and the coordinates of the plane at infinity are refined through a nonlinear least-squares optimization procedure. The results of our extensive experiments using both simulated and real data are also reported in this paper.     

Self-calibration of a binocular vision system based on a one-dimensional target

This paper proposes a method of self-calibration of a binocular vision system based on a one-dimensional (1D) target. This method only needs a 1D target with two feature points and the distance between the two points is unknown. During the process of computation, the distance value can be set an arbitrary value which is near the actual distance value. Using the method proposed in this paper, we can get the parameters of the binocular vision system including internal parameters of the two cameras and the external parameters (but there exists a non-zero scale factor in the translation vector which is connected to the initial distance value we set), the distortion parameters of cameras and the three-dimensional coordinates of the two points in different positions. In this paper, we determine theoretically that the initial distance value will not influence the results, and also the results of numerical simulation and experiment example are shown to demonstrate the method. Most importantly, this method is insensitive to the initial distance value, and it is the biggest advantage. In a practical application, we can use a 1D target with unknown distance to calibrate the binocular system conveniently; also we can use this method to calibrate the camera in a large field of view with a small 1D target.     

可程控精密直流参考源的设计

介绍了单片低功耗,具有片内自校准功能的20bit串行DAC1220数/模转换器在双极性DC参考源中的设计应用,并给出了与AT89C52系列单片机接口电路。     

光纤干涉绝对测距技术

提出一种利用短扫描导轨实现１ｍ以上绝对距离测量的光纤干涉测距新方法：测系统由定位干涉仪和扫描干涉仪组成,定位干涉仪采用准光光源实现测量中的定位瞄准,扫描干涉仪完成距离的测量。     

基于小波变换的视频能见度检测算法研究与实现

由于传统能见度仪价格昂贵、架设困难、不能给出道路能见度分布,提出了基于小波变换的视频能见度检测算法.利用摄像机自标定模型恢复图像距离信息,采用小波变换提取图像边缘特征点,使用能见度检测模型提取符合人眼的特征,结合曲线拟合,给出能见度变化曲线.该算法及其系统已在江苏宁常镇溧高速公路上进行试点使用,其结果与人眼及能见度仪检测误差在+10%之内,符合相关国际及国家标准.     

A Fractional-N CMOS DPLL with Self-Calibration

A digital phase-locked loop (DPLL) based on a new digital phase-frequency detector is presented.The self-calibration technique is employed to acquire wide lock range,low jitter,and fast acquisition.The DPLL works from 60 to 600MHz at a supply voltage of 1.8V.It also features a fractional-N synthesizer with digital 2nd-order sigma-delta noise shaping,which can achieve a short lock time,a high frequency resolution,and an improved phase-noise spectrum.The DPLL has been implemented in SMIC 0.18μm 1.8V 1P6M CMOS technology.The peak-to-peak jitter is less than 0.8% of the output clock period and the lock time is less than 150 times of the reference clock period after the pre-divider.