基于数字图像处理的自控显微镜聚焦算法研究

自动聚焦的评价函数是基于数字图像处理的自动聚焦算法的关键问题.从空域和频域详细分析了离焦图像的成像原理,利用带步长的拉普{记斯算子比较了一系列模糊l冬I像的清晰度.改进的拉普拉斯算子结合爬山法能够实现自控显微镜的高效率精确聚焦,是一种简洁实用的聚焦策略.改进后的聚焦评价函数具有灵敏度高、单峰值、无偏离、计算量小和较高的信噪比等特点.实验表明,与传统的梯度算子聚焦算法相比较,改进的自动聚焦算法效率更高,聚焦位置更精确.     

显微视觉系统的自动聚焦及控制

对自动显微镜的自动聚焦评价函数及聚焦控制策略进行了研究.首先,介绍了频域聚焦函数提升小波变换及时域聚焦函数Sobel-Tenengrad算子,通过将提升小波变换和Sobel-Tenengrad算子有机组合提出了一种新型聚焦评价函数.然后,利用离焦、正焦样本图像对自组织算法进行无监督训练,使用粒子群优化算法加速训练过程,并以经过学习的自组织映射算法作为聚焦控制器.最后,进行了显微视觉自动聚焦实验.实验结果表明:新型组合算子具有单峰性,峰值处变化陡峭,对不同样本、不同倍数物镜均可在正焦位置达到最大值,鲁棒性强;经过学习控制器后平均仅用7.6步即可完成自动聚焦,与爬山法相比,该聚焦算法不仅大大提高了聚焦速度且性能稳定,对每幅输入图像处理、识别时间约为120ms;满足了显微视觉自动聚焦要求,获得了良好聚焦效果.     

基于CPLD的高分辨力视频展台快速自动聚焦方法及实现

文中设计了一种基于复杂可编程逻辑器件(CPLD)和专用视频处理芯片的高分辨力快速自动聚焦视频展台。把显微镜的快速自动聚焦算法应用在教学视频展台上,具有实现简单、精度高、聚焦快等特点,利用CPLD编程的灵活性的特点进行设计,加快了数据处理的速度,节约了硬件上的成本。实验表明,该系统聚焦速度快、精度高、图像效果较好。     

基于加权邻域相关性的显微镜自动聚焦函数

目的：提出了一种基于加权邻域相关性的显微镜自动聚焦函数,并在研究显微镜聚焦原理及成像过程的基础上,分析了显微镜图像中像素邻域灰度相关性及像散现象对聚焦评价的影响。方法：首先,分别计算每幅显微镜序列图像中各像素与其四邻域像素的灰度相关性。然后,计算基于此相关性加权平均值的二次多项式聚焦函数,其中权值根据对应像素与显微镜视场中心的距离来确定。最后,选取该函数值最大的图像为聚焦图像。结果：实验结果表明,与经典的聚焦函数如方差函数、绝对梯度函数、Roberts梯度函数及Tenengrad函数相比,本文方法的聚焦灵敏度因子提高了0.3185~0.3268,噪声环境下聚焦的平均正确率提高了0~40%。结论：该方法能够准确地评价图像聚焦的程度,并具有较高的灵敏度和较强的抗噪性。     

基于窗口模式的自动聚焦算法

随着数字智能化技术的不断成熟与提高,自动聚焦技术也日益完善并广泛应用。简单介绍了目前一些经典的图像清晰度评价函数,并提出一种改进的拉普拉斯算子的图像清晰度评价函数。该算法把整幅图像分成不同的窗口,提出一个新的概念——兴趣参数,并引入至不同窗口。经过与其它一些经典算法进行大量的实验研究对比,证明该算法在聚焦的适时性、灵敏性和准确性上都具有一定的优越性。     

显微镜自动聚焦算法的研究

自动聚焦技术是全自动控制显微镜系统中的核心部分。自动聚焦算法综合了快速灰度差分法和高精度拉普拉斯函数法的优点,根据聚焦过程中各阶段聚焦评价函数的梯度选择合适的焦距评价函数和步长,并通过改变步长实现了从快速粗调到精确细调的过渡。实验表明,与传统的单一聚焦评价函数和单一步长的聚焦算法相比较,该算法在保证聚焦速度的情况下显著地提高了聚焦位置的精度。     

结核杆菌涂片显微视觉检测系统的自动聚焦

结核杆菌医学涂片大多具有观察区内容稀疏不均匀、杂质较多的特点,使用自动显微镜检方法进行图像采集时,会出现清晰度区分困难、效率低下、甚至聚焦评价失效的问题,为提高自动镜检的效率和准确度,本文自主搭建了显微视觉计算机自动检测系统,对结核杆菌涂片的自动聚焦技术进行系统的研究。首先,对比研究11种常用聚焦函数对结核杆菌镜检玻片图像聚焦评价的优劣,并分析了聚焦成功和失效的原因。在综合分析各聚焦函数对结核杆菌涂片的聚焦效果基础上,提出了一种基于Tenengrad的改进型聚焦评价函数,通过改进内容像素的聚焦权重提高聚焦准确度,优化图像处理算法来提高图像采集效率。实验结果表明:改进型Tenengrad聚焦函数FTen-Q在结核杆菌涂片的各类视野图像评价方面具有高灵敏度和准确度,其聚焦成功率和运算效率分别提高了13.884%和17.616%,可以满足结核杆菌涂片类非均匀涂片的显微视觉自动检测应用要求。     

一种改进型灰度差分聚焦算法研究与实现

为解决显微图像采集中聚焦的准确性和快速性,设计并实现了一种包括图像采集端、图像处理算法实现模块、OSD菜单实现模块、系统控制模块和HDMI输出模块等硬件采集系统。结合实际应用和现有的图像处理算法,提出了适合数字显微图像的图像预处理自动聚焦算法,在灰度差分绝对值之和函数的基础上增加了对周围点的判断,提高了算法的精确度。实验结果表明,通过对切片图像在显微镜物镜10倍、40倍、100倍下采集到的离、聚焦图像以及聚焦曲线呈现单峰性,无偏性等特点,能实现良好的聚焦能力。     

基于ARM7处理器的快速聚焦方法

快速、准确地自动聚焦是获取高质量图像信息的前提。现对基于ARM7处理器和CCD图像传感器的自动聚焦系统进行研究,对模拟视频信号滤波提取高频分量作为判据的方法进行探讨,根据实际需要进行滤波选频和带宽选择,对系统实现中的关键技术进行了详尽的分析讨论。同时,针对系统在自动聚焦过程中实际出现的问题,对聚焦评价函数和搜索策略进行了优化,使系统的聚焦更加准确,并给出相应的实验结果。实验表明,该方法提高了聚焦的精度和速度,并且已成功应用于显微镜自动调焦系统中。     

基于二进小波多分辨率逼近的层析三维数字化图像边缘检测研究

采用Ｂ样条小波来提取层析图像的边缘轮廓,用高斯函数为平滑函数,用Ｍａｌｌａｔ快速算法进行小波分解,分解出的局部极值就是层析图像多尺度边缘。这两种算法在不同的尺度下有不同的提取边缘细节的能力和抑制噪声的能力。做到了抑制噪声和提取边缘细节之间有机的统一。结果证明这种方法比传统的基于微分算子的边缘提取方法更适合于层析图像边缘轮廓的提取     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

RLS and LMS blind adaptive multi-user detection method and comparison in acoustic communication

RLS and LMS blind adaptive multi-user detection algorithm and multi-user detector was proposed to solve the problem of multi-user signal detection problem encountered in underwater acoustic communication networks.In simulation analysis,RLS and the LMS blind adaptive multi-user detector were designed and tested for synchronous and asynchronous multi-user communication process.The results of SIR comparison and MMSE comparison show that,both of the two methods can realize blind adaptive detection when any user change in multi-user communication,during this process,the training communication sequences are not needed.The RLS algorithm has about 5 dB higher in SIR compared with LMS algorithm,and the convergence velocity of RLS algorithm is also higher than LMS algorithm when the communication users change.RLS algorithm has better ability in multi-user detection than that of LMS algorithm,and it has great attraction and guiding significance for solving the problem of multiple access interference(MAI) in multi-user communication.     

Robust Impedance Control of Robots Using an Adaptive Interaction Force Observer

For robot interaction control,the interaction force between the robot and the manipulated object or environment should be monitored.Impedance control is a type ...     

Research on key techniques of expendable conductivity temperature depth measuring system

This paper analysis the developing of expendable conductivity temperature depth measuring system(XCTD)and introduce its principle of measuring about temperature,salinity and depth of ocean.Some key techniques are put forward.According to the real needs of XCTD,conductivity sensor with high sensitivity is designed by principle of electromagnetic induce,the ocean conductivity from induced electromotive force has been calculated.Adding temperature correction circuit would help to reduce error of conductivity measurement because of sharply changing temperature.Advanced temperature measuring circuit of high precision and the constant current source is used to weaken effect of self-heating of resistance and fluctuation of the source.On respect of remote data transmission,LVDS is a good choice for the purpose of guarantee the quality of data transmitted and the transmission distance is reaching to thousand meters in the seawater.Modular programming method is also brought into this research aimed at improve the stability,reliability and maintainability of the whole measuring system.In February,2015,the trials in South China Sea demonstrate that the developed XCTD realize effective measurement at a speed of 6 knots and detection depth at 800 m.The consistency coefficient of the acquired data is greater than 0.99 and the success rate of probe launching is above 90%.     

CHARACTERISTCS OF FLUID FILM IN OPTIMIZED SPIRAL GROOVE MECHANICAL SEAL

In order to investigate the sealing performance variation resulted from the thermal deformation of the end faces, the equations to calculate the fluid film pressure distribution, the bearing force and the leakage rate are derived, for the fluid film both in parallel gap and in wedgy gap. The geometrical parameters of the sealing members are optimized by means of heat transfer analysis and complex method. The analysis results indicate that the shallow spiral grooves can generate hydrodynamic pressure while the rotating ring rotates and the bearing force of the fluid film in spiral groove end faces is much larger than that in the flat end faces. The deformation increases the bearing force of the fluid film in flat end faces, but it decreases the hydrodynamic pressure of the fluid film in spiral groove end faces. The gap dimensions which determine the characteristics of the fluid film is obtained by coupling analysis of the frictional heat and the thermal deformation in consideration of the equilibrium condition of the bearing force and the closing force. For different gap dimensions, the relationship between the closing force and the leakage rate is also investigated, based on which the leakage rate can be controlled by adjusting the closing force.