基于镜面反射的手眼标定方法

针对Eye-on-Hand机器人手眼系统的标定问题,提出一种基于镜面反射的手眼标定方法。通过镜面反射获取图像,根据镜像原理,通过线性求解算法确定机器人末端执行器和相机坐标系的位姿关系。与以往的标定方法不同,该方法只需要3次改变平面镜的姿态,就能同时获得相机的内参数和手眼视觉系统的位姿关系,不会引入传统标定方法中利用机器人运动参数而产生的机器人运动误差。最后将其与Halcon手眼标定算法进行对比,验证了所提方法的正确性和可行性。     

理论分析光偏振对导光管光传输效率的影响

光传输效率(LTE)是衡量导光管采光性能的最重要参数。在导光管LTE计算中，常常忽略了光线在管中若干次镜面反射引起的光偏振的累积效应。因此，为厘清连续镜面反射引起光偏振的累积效应，通过光学理论分析与公式推导，在确定光偏振对镜面反射材质反射率的影响之后，首次揭示了导光管内壁反射率随反射次数的变化规律，以及反射率的变化对导光管LTE的影响。结果表明：单束自然光线每投射到管内壁一次，就会产生一次光偏振，并在两个正交分量上产生不同的反射率，即ρ_⊥和ρ_‖,且ρ_⊥≥ρ_‖;历次反射中ρ_⊥和ρ_‖数值保持不变，但整体反射率会随反射次数增多而逐渐变大，故导光管内光损速率会不断减缓；由此提出了导光管中单束光线的LTE表达式，为建立复杂光源下LTE数学计算模型，奠定了理论基础。     

基于格子波尔兹曼模型的内镜图像高光修复

在内窥镜检查中,由于器官内腔粘膜表面黏液对光源的反射,高清图像中常常存在高光。高光的修复对内窥镜检查和诊断具有重要的临床意义。本文提出一种基于四元数和格子波尔兹曼模型的高光修复方法,首先通过四元数表达高清图像的彩色信息,然后利用四元数旋转操作表达两个像素的色差,并将色差引入到格子波尔兹曼模型的松弛因子设计中,最后利用格子波尔兹曼模型的扩散实现高光的修复。实验结果表明,该方法修复高光效果更好,局部区域细节保持效果提升了50%,颜色保持效果提升了5倍。     

小斜率近似方法分析粗糙界面声散射问题

利用小斜率近似方法计算了起伏海面的声散射特性,得到了具有高斯分布粗糙海面的平均反射系数（即镜反射系数）计算公式,并与微扰法和Kirchhoff近似做了比较,结果表明小斜率近似是一种非常有效的分析起伏表面散射特性的近似方法。最后讨论了海面镜反射系数随海面的不平整度（波浪的均方根高度）、声波频率和声波入射方向的变化关系,得出了只有在声波波长和起伏波浪高度可比拟时,才有明显的镜反射的结论。这为分析浅海目标声散射特性时,选择是否需要考虑海面（海底）所引起的多途效应提供了理论依据。     

海面多路径效应对被动微波测角的影响分析

在拦截超低空目标时,海面多路径效应会严重影响被动制导型舰空导弹的测角精度。首先阐述海面多路径效应产生机理,然后结合旋转式相位干涉仪的测角原理,通过建立海面多路径镜面反射几何模型,给出了双天线直达信号和镜面反射信号表达式。在此基础上,选取典型超低空弹道,根据仿真结果代入多路径计算模型,分析超低空弹道多路径效应对测角精度的影响。仿真结果表明,海面多路径效应对被动微波体制导引头测角影响显著,为下一步研究抑制多路径影响措施提供了重要参考。     

Conformational rearrangements in interfacial region of polydimethylsiloxane melt films

Synchrotron X-ray reflectivity (XRR) confirms the formation of a quasi-immobilized layer in thin films of polydimethylsiloxane (PDMS) melts near silica surfaces. This layer (40-60 Å) has a lower density than the bulk value, and its thickness varies slightly with PDMS molecular weight. Formation of this layer is very rapid for PDMS melts with low molecular weights (below entanglement limit for these molecules) but takes 5-10 h for higher molecular weights (close to and above their entanglement value).     

非镜面散射条件高度测量研究

以现代信号处理和火箭外弹道理论为基础，综合利用武器系统和引信的先验信息，研究了在弹丸具有任意落速、落角、目标为平坦地面和非镜面散射条件下，引信距离面目标的垂直高度确定问题。从理论上解决了在假设条件下引信炸高测量问题，并给出了高度测量的具体运算方法。     

Radiation heat transfer in three‐dimensional closed space including diffuse and specular surfaces

A method of numerical calculation for radiation heat transfer in a three‐dimensional closed space including diffuse and specular surfaces was developed. To enable an analysis of the radiation heat exchange on each surface considering multiple specular reflections and obstacles to radiation in the space, an improved heat ray‐tracing method was presented to calculate view factors accurately. The method was determined to be applicable to complicated problems in test calculations using models with specular surfaces and obstacles. Continuing efforts are being applied to more realistic problems. The example examined in this paper is an infrared emitter with a parabolic specular reflector, which is a conventional electric heating apparatus. The measured result for radiant power distribution agrees well with the calculated one. The practical validity of our method was verified. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(2): 108–129, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.10074     

一种新的非均匀介质表面漫反射光成分提取方法

在非均匀介质表面,强光是漫反射光成分和镜面反射光成分的线性组合．结合非均匀介质表面反射特点和漫反射光成分之间的线性组合关系,文中提出一种新的基于测定光度的线性化方法,它可以计算出不同光照条件下图像之间的线性组合系数,并在此基础上提取非均匀介质表面漫反射光成分．实验结果表明,该方法可以有效地提取真实瓷器表面的漫反射光成分．     

Method for Calculation of Sky Light Luminance Aiming at an Interactive Architectural Design

Recently, computer graphics are frequently used for both architectural design and visual environmental assessment. Using computer graphics, designers can easily compare the effect of the natural light on their architectural designs under various conditions, such as different times of day, seasons, atmospheric conditions (clear or overcast sky) or building wall materials. In traditional methods of calculating the luminance due to sky light, however, all calculation must be performed from scratch if such conditions undergo change. Therefore, to compare the architectural designs under different conditions, a great deal of time has to be spent on generating the images. This paper proposes a new method of quickly generating images of an outdoor scene, taking into account glossy specular reflection, even if such conditions change. In this method, luminance due to sky light is expressed by a series of basis functions, and basis luminances corresponding to each basis function are precalculated and stored in a compressed form in the preprocess. Once the basis luminances are calculated, the luminance due to sky light can be quickly calculated by the weighted sum of the basis luminances. Several examples of an architectural design demonstrate the usefulness of the proposed method.