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1.
利用图像处理实现平面工作台三自由度位移的同步检测   总被引:2,自引:0,他引:2  
吴鹰飞  周兆英 《光学技术》2002,28(4):326-328
为了实现平面工作台三自由度位移的同步检测 ,研制了图像处理位移检测系统。以CCD相机为核心 ,结合显微镜放大、图像采集和图像处理构成检测系统。图像处理软件用VC编制 ,计算并绘制了工作台三自由度位移随时间的变化关系 ,以及工作台在平面内的运动轨迹。系统的位移检测不受工作台大幅转动的影响。检测系统达到了亚像素级的位移分辨率。选择合适的显微镜放大倍率 ,可使检测系统既有较高的位移分辨率 ,又有一定的位移检测范围  相似文献   

2.
纳米级两维微位移工作台的参数测试   总被引:1,自引:0,他引:1  
崔岩梅  周自力  曹航 《光学技术》2002,28(5):447-448
为了分析纳米级两维微位移工作台引入的测量误差 ,介绍了其机械结构及工作原理 ,进行了定位准确度实验和运动方向的直线度 (偏摆 )实验 ,实验结果表明 ,工作台的定位准确度较高 ,运动方向的直线度在工作台工作范围内无需修正 ,即可满足高精度测量的需要  相似文献   

3.
手-眼视觉动态目标定位方法研究   总被引:3,自引:1,他引:2  
提出了一种机器人手-眼视觉分步动态目标定位方法,实验中保持摄像机图像平面与工作台平面平行,通过摄像机在不同高度对工作台上目标的分步拍摄并获取目标位置信息,将目标定位的三维关系简化为二维关系处理。在摄像机对目标定位的过程中,目标位置信息被不断修正,最终将目标定位在图像的中心位置,进而引导末端执行器完成对目标的准确抓取。实验结果显示该手-眼视觉分步动态目标定位方法定位准确、可靠性高。  相似文献   

4.
基于时反算子分解的时反高分辨率定位技术研究   总被引:2,自引:0,他引:2  
基于时反算子分解技术,提出了主动时间反转选择性定位方法.为提高此定位方法的分辨率,根据时反算子和协方差矩阵的相似性,提出了时反MUSIC和对角线加载时反MVDR定位技术.传统的获取时反算子的方法是通过单个阵元依次发射,该方法的缺点是每次只有单个元发射,导致输入信噪比较小,本文提出通过多个波束正交发射获取时反算子,能得到较大的输入信噪比,从而改善三种定位方法的定位性能.波导实验分别对三种定位方法和正交发射技术进行了验证,结果显示三种定位算法中,子空间基于的时反MUSIC方法具有较好的定位精度,时反MVDR技术具有较高的分辨率.  相似文献   

5.
鉴于空间光通信系统中分辨率在很大程度上影响着整个通信系统的性能,而PSD(position sensitive detector)作为APT(acquisition, pointing and tracking)子系统常用的探测器件,具有分辨率高,无盲区,响应速度较快的优点,分析了PSD的基本结构和定位原理,研究了使用PSD作为空间光通信APT子系统粗跟踪技术的位置分辨率,并指出了提高PSD分辨率的着手点。用实验方案对PSD的分辨率进行了具体的实验分析。通过对实验数据分析可知,PSD的平均位置分辨率达到12.6μm,该值与理论分辨率吻合得较好。这说明PSD作为APT子系统精跟踪探测器的可行性。  相似文献   

6.
皮少华  王冰洁  赵栋  贾波 《物理学报》2016,65(4):44210-044210
基于Sagnac结构的分布式光纤干涉仪具有灵敏度高和动态范围大等特点, 特别适合监测入侵信号, 并确定其发生位置. 不同于现有的时域自相关及频域陷波点定位方法, 本文提出将两相干光束相位差信号变换到倒谱域, 通过倒谱系数峰来方便准确地确定入侵位置. 此外, 为克服倒谱定位中降采样带来的分辨率粗糙问题, 提出了多分辨率定位综合的改进方法. 通过改变降采样因子和利用高阶倒谱峰两种措施对同一入侵信号得到一系列定位值, 并对所有定位值取平均作为入侵信号的最终定位值. 实验首先在距离传感光缆尾端40.498 km处制造3个入侵信号. 采用本文提出的倒谱方法对该入侵得到84个定位值, 综合后的定位误差分别只有9 m, 17 m 和 11 m, 显示了对入侵信号定位的准确性. 之后对不同位置的入侵信号进行定位, 7次实验的定位误差的标准差达到12 m, 而相同情况下的自相关方法和陷波点方法的定位误差标准差分别为695 m和118 m. 此外, 这种方法还具有操作简单、易于自动测量等特点, 有望在Sagnac干涉传感系统中发挥重要作用.  相似文献   

7.
机械振动是物理学研究的一个重要内容,但在教学中存在两个问题:一是其中一些概念、理论较抽象,难于理解,学生学习有一定难度.二是教学中研究的是单自由度振动系统,而实际生产、生活中所见到的振动现象,都属于多自由度振动系统,二者差距很大.为此我们设计并制做了悬臂梁受迫振动实验仪,帮助学生掌握振动基本理论,又可对实际振动现象有所了解.一、测振系统的设计原理1.工作台结构该工作台结构如图1所示.要求底座和支架要有足够的稳定性和刚度,悬臂梁为矩形截面梁,弹性要好,伸出端的长短可通过压板调节(还可换上不同刚度、质量及…  相似文献   

8.
活体小动物成像系统是疾病研究、新药开发的重要组成部分.其中,X射线微型锥束计算机断层成像(X-ray micro cone-beam computed tomography,Micro-CBCT)能实现数十至数百微米空间分辨率的解剖结构成像研究.Micro-CBCT成像仪的一个关键挑战是其空间和对比度分辨率主要取决于X射线源焦斑大小、探测器分辨率和系统几何结构等因素.为提高Micro-CBCT的空间分辨率、对比度分辨率和成像均一性,本文基于毛细管X光透镜研制了一款能够调控照射X射线束斑孔径的Micro-CBCT扫描仪,用于小动物成像研究.此系统由微焦斑X射线源、非晶硅平板探测器、旋转工作台和控制电脑组成,并采用Feldkamp-Daivs-Kress算法重建投影图像.对该系统的性能进行了测试,结果表明,系统在10%调制传递函数下的空间分辨率为9.1 lp/mm,提高了1.35倍.同时,由于毛细管X光透镜对低能X射线的吸收和散射抑制作用,实现了2倍以上的对比度增强,减轻了多色X射线束硬化效应引起的图像均一性恶化问题.应用该Micro-CBCT系统对麻醉小鼠进行了活体成像,验证了该系统在小...  相似文献   

9.
基于图象灰度分布的边缘中心定位算法   总被引:13,自引:12,他引:1  
刘卫光  周利华 《光子学报》2003,32(9):1122-1125
提出了一种对图象线性边缘检测的精确定位算法,传统方法是基于系统分辨率的定位方法,其精度最高只能达到一个象素.该算法利用了图象象素的亮度信息,用概率分布方法进行定位估值,使定位精度小于一个象素,即在较低系统分辨率的情况下,获得较高分辨率的定位精度,用此算法设计的自动测量系统,在实际使用中取得了令人满意的结果.  相似文献   

10.
提出了一种机器人"手-眼"视觉分步动态目标定位方法,实验中保持摄像机图像平面与工作台平面平行,并对摄像机的拍摄高度进行设定,最终将目标定位在图像的中心位置。在目标类型识别过程中,采用BP神经网络技术对目标表面字符进行识别,通过识别的字符判定目标类别。最终由字符信息及目标定位信息引导末端执行器完成对目标的准确分选。  相似文献   

11.
We develop a displacement measurement and positioning system with nanometer resolution over the millimeter traveling range. The method is based on a heterodyne grating shearing interferometry, a homemade lock-in amplifier and a servo control loop for displacement sensing and positioning. The quasi-common optical path configuration of our system provides better immunity against environmental disturbances. The experimental results demonstrate that our system can measure small and long displacement with nanometric resolution. The device achieves a positioning resolution of 2.3 nm over a traveling range of 20 mm.  相似文献   

12.
Snitka V 《Ultrasonics》2000,38(1-8):20-25
This paper deals with ultrasonic motors based on bimodal plate vibrations and their application to nanometre resolution stepper positioning systems. The concept of a linear ultrasonic motor drive capable of nanometric steps, long-range travel and reversible controlled motion is presented. The motor concept developed is based on the superposition of a longitudinal and bending vibrations of a rectangular resonator. The ultrasonic motor model based on system identification via discrete observations and prediction has been developed for control applications. The control algorithm for ultrasonic motors has been developed and theoretical investigations have been made. The open loop positioning system with designed stepper ultrasonic drive produced 10 nm resolution and 5% displacement repeatability. The system with computer controlled position feedback has shown 0.3 micron positioning accuracy over the 100 mm positioning range.  相似文献   

13.
利用声源定位技术测量弹丸落点坐标时,针对多发炮弹短间隔连续射击试验中,传感器接收信号的时序关系复杂,严重影响声源定位结果准确性的问题,提出了采用模拟退火遗传算法实现短间隔连续多声源目标的精确定位。试验测试了发射间隔为0.15 s的7发炮弹在600 m×600 m区域内的定位情况,结果表明:文章的算法能快速有效的对短间隔连续多声源目标进行定位解算,定位精度小于5 m。  相似文献   

14.
A new honeycomb core design has been used to increase the stiffness of the panel and applied to improve the noise transmission loss at frequencies between 100 and 200 Hz. A model is presented to predict the transmission loss of the honeycomb panels based on the structural modal parameters. A new test specimen with fiber reinforced plastic cores and face sheets had been used to investigate the effect of stiffness and damping on noise transmission loss. The measurements of noise transmission loss have been compared with data for common structural panels. The results show that the new core fabrication techniques using moulding to improve the noise transmission are effective. In comparison to a cement panel of the same mass, the honeycomb panels have higher TL at low frequencies between 100 and 200 Hz due to higher stiffness and damping. The honeycomb panels have more significant vibration responses above 500 Hz but these are limited by damping.  相似文献   

15.
消光起伏光谱法(TFS)是一种新的颗粒测量方法,可同时测量两相流中颗粒的粒径分布和体积浓度。由于在测量原理和结构上非常简单,这种方法可用来实现在线、实时测量。然而在实际测量中,消光起伏光谱法对颗粒粒径分布的分辨率还比较低且对高浓度颗粒系的测量须考虑颗粒相互作用效应。本文提出一种新的数据处理方法-消光起伏相关光谱法(TFCS),通过对消光起伏信号在不同相关时间参数下进行相关计算来得到消光起伏光谱以提高消光起伏法对颗粒粒径分布的分辨率。  相似文献   

16.
Analysis on the positioning precision of CAPS   总被引:1,自引:1,他引:0  
As a newly developed satellite positioning system, the Chinese Area Positioning System (CAPS) is a typical direct sequence spread spectrum ranging system like GPS. The positioning precision of such navigation signals depends on many factors, including the pseudo-code rate, the signal to noise ratio, the processing methods for tracking loops and so on. This paper describes the CAPS link budget, the solution approach for CAPS positioning, focusing on the autocorrelation function feature of C/A code signals. The CAPS signal measurement precision is studied by the software approach together with theoretical analysis of the range resolution. Because the conventional Delay Lock Loop (DLL) is vulnerable to the impact of noise, a narrow correlator and multiple correlators as well as the corresponding discrimination methods of phases are proposed, which improves the robustness of DLL and the code-phase resolution of the measurement. The results show that the improvement of the DLL structure and the discrimination method are the most important way to improve the ranging resolution. Theoretical analysis and experimental results show that a CAPS receiver could reach a 20-m positioning precision by using three satellites with a supported height from an altimeter. Supported by the National Key Basic Research and Development Technology Plan (Grant No. 2007CB815500) and the National Natural Science Foundation of China (Grant No. 60802018)  相似文献   

17.
基于莫尔信号的精密位移测量与控制的研究   总被引:1,自引:0,他引:1  
应用光衍射理论分析了一种纳米级位移分辨率的双级衍射光栅测量系统,建立了衍射莫尔信号与对应位移的数学模型,并通过计算机仿真对莫尔信号的位移特性进行了研究。在此基础上构建了一套精密位移测量与控制装置,取差动零次激光莫尔信号为控制信号,由微机控制实现高精度位移检测及全自动精密定位。实验结果表明,基于激光莫尔信号的精密检测与控制装置可获得得5nm的位移分辨率及±0.4μm的定位精度。  相似文献   

18.
A combination of light-emitting diode(LED) identification and a time-division multiplexing scheme is proposed in this Letter for indoor location-based service. With the scheme, the arrangement of white LED lamps and the structure of a data frame are designed to realize high-accuracy indoor positioning and location-based payload data transmission simultaneously. The results of the experiment demonstrate that the indoor positioning accuracy is 10 cm and 2 Mb/s data transmission with high signal quality is realized.  相似文献   

19.
李缙  张丕状 《应用声学》2018,37(2):232-237
针对在军事演习或爆炸实验中对冲击波超压传感器位置的精确定位,设计了一种实时主动声定位系统。该系统由声信号发射系统、声信号接收处理系统和无线监控终端系统三部分组成。声信号发射系统与无线监控终端以单片机STC12C5A60S2作为核心控制器,接收处理系统以ARM9系列的S3C2440作为核心控制器。发射系统发射四种已知频率的声信号,接收处理系统接收并处理收到的四种声信号,然后把处理结果反馈到无线监控终端。通过实验表明,该系统在一定条件下,能够稳定地发射、接收并处理声信号,达到实时定位目标,并在200 m范围内将定位误差控制在厘米级内。  相似文献   

20.
The purpose of this study was to determine an optimal condition (vibration frequency and image filtering) for stiffness estimation with high accuracy and stiffness measurement with high repeatability in magnetic resonance elastography (MRE) of the supraspinatus muscle. Nine healthy volunteers underwent two MRE exams separated by at least a 30 min break, on the same day. MRE acquisitions were performed with a gradient-echo type multi-echo MR sequence at 75, 100, and 125 Hz pneumatic vibration. Wave images were processed by a bandpass filter or filter combining bandpass and directional filters (bandpass-directional filter). An observer specified the region of interest (ROI) on clear wave propagation in the supraspinatus muscle, within which the observer measured the stiffness. This study assessed wave image quality according to two indices, as a substitute for the assessment of the accuracy of the stiffness estimation. One is the size of the clear wave propagation area (ROI size used to measure the stiffness) and the other is the qualitative stiffness resolution score in that area. These measurements made by the observer were repeated twice at least one month apart after each MRE exam.This study assessed the intra-examiner and observer repeatability of the stiffness value, ROI size and resolution score in each combination of vibration frequency and image filter. Repeatability of the data was analyzed using the intraclass correlation coefficient (ICC) and 95% limits-of-agreement (LOA) in Bland-Altman analysis. The analyses on intra-examiner and observer repeatability of stiffness indicated that the ICC and 95% LOA were not varied greatly depending on vibration frequency and image filter (intra-examiner repeatability, ICC range, 0.79 to 0.88; 95% LOA range, ±23.95 to ±32.42%, intra-observer repeatability, ICC range, 0.98 to 1.00; 95% LOA range, ±5.10 to ±10.99%). In the analyses on intra-examiner repeatability of ROI size, ICCs were rather low (ranging from: 0.03 to 0.69) while 95% LOA was large in all the combinations of vibration frequency and image filter (ranging from: ±62.66 to ±83.33%). In the analyses on intra-observer repeatability of ROI size, ICCs were sufficiently high in the total combination of vibration frequency and image filter (ranging from 0.80 to 0.87) while the 95% LOAs were better (lower) in the bandpass-directional filter than the bandpass filter (bandpass directional filter vs. bandpass filter, ±28.81 vs. ±54.83% at 75 Hz; ±25.63 vs. ±37.83% at 100 Hz; ±34.51 vs. ±43.36% at 125 Hz). In the analyses on intra-examiner and observer repeatability of resolution score, the mean difference (bias) between the two exams (or observations) was significantly low and there was almost no difference across all the combinations of vibration frequency and image filter (range of bias: −0.11–0.11 and −0.17–0.00, respectively).Additionally, effects of vibration frequency and image filter on wave image quality (ROI size and resolution score) were assessed separately in each exam. Both mean ROI size and resolution score in the bandpass-directional filter were larger than those in the bandpass filter. Among the data in the bandpass-directional filter, mean ROI size was larger at 75 and 100 Hz, and mean resolution score was larger at 100 and 125 Hz. Taking into consideration with the results of repeatability and wave image quality, the present results suggest that optimal vibration frequency and image filter for MRE of the supraspinatus muscles is 100 Hz and bandpass-directional filter, respectively.  相似文献   

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