一种新的三维测量机器人手眼标定方法

为了提高三维测量机器人的手眼标定精度以更好地满足工业需求,提出了一种采用动态改变变异率的自适应差异进化算法进行手眼标定的新方法。首先构建了由线结构光测头和机器人组成的视觉测量系统,利用齐次坐标变换的方法建立了测量系统的数学模型;然后针对数学模型中的手眼关系,使用半径已知的球体,采用定点变位姿的方法,进行粗略的估计,并对手眼关系求解的精度进行分析;最后采用动态改变变异率的自适应差异进化算法对手眼关系做进一步寻优。实验结果表明,算法具有较高的求解精度。该方法用于手眼标定是可行的、有效的,整个标定过程简单,便于实际应用。     

Influence of the Alkyl Chain Length on the Self‐Assembly of Amphiphilic Iron Complexes: An Analysis of X‐ray Structures

Several new amphiphilic iron complexes were synthesised and characterised by single crystal X‐ray structure analysis. The Schiff‐base‐like equatorial ligands contain long alkyl chains in their outer periphery with chain lengths of 8, 12, 16 and 22 carbon atoms. As axial ligands methanol, pyridine, 4‐aminopyridine, 4‐(dimethylamino)pyridine and 1,2‐bis(4‐pyridyl)ethane were used. X‐ray structure analysis of the products reveals different coordination numbers, depending on the combination of equatorial and axial ligand. The driving force for this is the self‐assembly to lipid‐layer‐like arrangements. This can be controlled through the chain lengths and the dimension of the axial ligands in a crystal‐engineering‐like approach. For this an empirical rule is introduced concerning the crystallisation behaviour of the complexes. The efficacy of this rule is confirmed with the crystallisation of an octahedral complex with two docosyl (C22) chains in the outer periphery. The rule is also applied to other ligand systems.     

Surfactant Chain Length Effect on the Structural Parameters of Nonionic Microemulsions

In this study we estimated the structural parameters of (water+propylene glycol)/sucrose esters/(benzaldhyde+ethanol) systems. The weight ratios of water/propylene glycol and that of benzaldhyde/ethanol equal 2 and 1, respectively. The sucrose esters were sucrose laurates (L595, L1695, and SM1200), sucrose myristate (M1695), sucrose palmitate (P1670), sucrose oleate (O1570), and sucrose stearate (S1570). The pseudoternary phase behavior at 37°C was explored to determine the extension of the microemulsion phase regions. A one‐phase microemulsion region extending from the oil rich region to the water rich corner was observed in these systems. It was found that minor changes in the surfactant chain length, structure, and composition suffice to provoke a considerable change in the aggregation number, core radius and interfacial area per surfactant and cosurfactant molecules head groups in the formed microemulsions. The interfacial area per surfactant head group decreases with the increase in the surfactant chain length. For a sucrose ester with a given chain length the interfacial area per surfactant head group decreases with the increase in the surfactant monoester content. The interfacial area per surfactant head group increases with the increase in the surfactant concentration and the water core volume in the formulated microemulsions.     

光学头光束孔径匹配

光学头是光盘存储器的核心部件，光学头光束孔径匹配是光学头设计的一个至关重要的问题。必须合理地确定光源的光束口径与光盘物镜孔径比值，才能保证其光能量耦合效率，并获得较小的光斑尺寸和合理的焦深。本文以衍射光学为基础，详尽地分析了光束孔径匹配对光能耦合效率、光斑尺寸、物镜焦深的影响。     

电视导引头跟踪系统物理建模与分析

对某型空地导弹电视导引头进行实测建模，通过建模和仿真分析，对系统提出改进意见。     

用于微电子硅芯片液晶显示的反射式中继目视系统

设计了用对角为 18mm的微电子硅芯片液晶显示器、6 0°视场角的反射中继头盔显示系统。该系统由一个常用的艾尔弗 (Erfle)接目镜和一个反射中继镜组成。反射中继镜和接目镜的场曲异号 ,因此相互部分抵消 ,系统具有较小的场曲和像散。中继系统的采用 ,不仅保证了头盔显示的特定规格要求 ,诸如出瞳直径和出瞳距离 ,而且为反射式微电子硅芯片液晶显示器的照明光源提供了空间。该系统像差较小 ,尺寸和重量合理 ,适用于特定用途的头盔显示     

集中受热的晶体和镜子的冷却问题和热变形问题

1引言以接近光速运动的电子转弯时会沿轨道切线方向在非常小的立体角内（通常小于1mrad）发出强烈的电磁幅射，它被称为同步幅射。近年来随着同步辐射功率增加同步辐射装置中镜子和晶体的冷却问题越来越引起人们注意[1-3]。现在计算机能力越来越强，使我们能够更精细地以第三类边界条件研究三维温度场及其相应的变形场。2温度场同步辐射装置中镜子和晶体冷却问题可以看成在高斯分布的热源和均匀的热沉之间的热传导。很久以前有人研究过这类问题[4]。他们假设边界条件为第一类。在我们研究的问题中第三类齐次边界条件更接近实际情况[5]。我们…     

非球面超光滑加工磨头控制技术研究

为了避免在超光滑加工过程中破坏光学元件的原有面形,同时保证整个表面粗糙度的均匀一致,研究了超光滑加工过程中的磨头控制技术.首先分析了超光滑加工机床的结构形式及超光滑加工工艺特点;然后研究了非球面母线的双圆弧拟合算法以及磨头进给速度的控制方法;最后将所研究的磨头运动控制算法应用于超光滑加工控制软件.以顶点曲率半径为300...     

Interaction phenomena of ion‐acoustic quasi‐solitons and classical‐solitons in three component plasma

The space–time evolution of the cnoidal‐soliton solution, characteristics of the quasi‐soliton solution of Korteweg‐de‐Vries (KdV) equation, and the interaction phenomena of ion‐acoustic waves (IAWs) are investigated in a plasma system consisting of positive and negative ions with superthermal electrons. To do this, and (Ar⁺, F^?) plasmas are considered and two‐sided KdV equations (KdVEs) are derived applying the extended Poincaré‐Lighthill‐Kuo (ePLK) method. The effects on wave structures, potential profiles, and propagation characteristics with plasma parameters of the cnoidal‐wave, quasi‐soliton solution, and head‐on collision phenomena of IAWs are presented graphically. It was found that the superthermality parameter and the mass ratio of ions play a significant role in the head‐on collision between soliton and standing cnoidal wave and reveal that the collision is elastic and both waves change their phase shifts due to collision. Moreover, the superthermality parameters are also responsible for the production of compressive and rarefactive phase shifts in overtaking collision processes between right travelling classical soliton (CS) and cnoidal wave (CW) and reduced the amplitudes of IAWs. It was also found that a new wave is created with a high amplitude in the interacting region during collision depending on the plasma parameters.