The visual fiducial based pose estimation of mobile manipulator in large-scale components manufacturing

The accurate estimation of the end-effector’s pose in large operating spaces is the key for the mobile manipulator to realize efficient manufacturing of large and complex components. We propose a novel pose tracking method in large-range using visual fiducial markers, and further propose the layout optimization method for the encoded fiducial markers. A metric named orientational dilution of precision (ODOP) is proposed to evaluate the magnification of the pose estimation error compared with the measurement error of the coded fiducial markers. The distribution pattern of the coded markers is analyzed based on ODOP, and the square-shaped layout is determined to be a satisfactory distribution pattern for the minimum positioning unit of markers, and the side length of the square-shaped layout is further selected. The simulations and experiments prove the effectiveness of the ODOP index. Finally, the square-shaped layout and the designed distribution density for positioning coded markers are adopted to realize the high-precision measurement of large components by the mobile manipulator.

     

测试驱动开发探讨

测试驱动开发是一种新的软件开发方式。探讨了测试驱动开发方法对于软件开发的各个阶段的影响,并探讨了测试驱动开发方法的优点及其存在的问题。测试驱动开发能够提高代码的质量,帮助设计出可重用和可测试性的代码,是一个有影响的研究方向。     

长沙市劳动路湘江隧道岩溶发育特征及其影响

岩溶是地下水地质作用的过程和结果,是隧道建设面临的不良地质现象之一,对隧道工程建设影响极大。采用物探与钻探相结合的勘察手段,查清了场地范围内的地层岩性及水文地质条件。通过对隧址地形地貌、地层岩性、地质构造、地表水系、地下水的补、径、排条件综合分析,查明了岩溶发育程度及其规律,分析了岩溶对隧道工程建设的影响,提出了应对措施。     

On the tension necking of copper single crystal specimen under slip deformation mechanism

The tension necking of FCC copper single crystal specimen with a square cross section was analyzed under the slip deformation mechanism. The actual clamp manner of the specimen was modeled by setting correlative boundary condition,and the small angle deflection between tension loading axis and crystallography axis [100] was taken into account. The finite deformation numerical analysis of three-dimensional necking deformation for the specimen was performed by apply-ing crystal plasticity theory associated with a numerical algorithm suggested by the first author. According to the comparison with experimental observation,the fact was confirmed that the numerical results could describe the loading elongation curve of the copper single crystal specimen under large strain tension reasonably,and the method could be used to investigate the necking characteristic in neck shape and the effect due to the small angle deflection. Further,the investigation into the influence of specimen cross-section shape on necking was also performed;the results on mechanical response and neck profile evolution obtained through modeling of cylindrical specimen were compared with those obtained with square cross-section specimen.     

用代表中值损伤的"飞行大纲"编排飞机载荷谱的方法

通过对飞机使用情况的统计分析,在“用中值寿命(损伤)代表起落编制飞机载荷谱方法”的基础上,提出用代表中值损伤的飞机实用“飞行大纲”来编排各代表起落的编谱方法。按这种方法编出的载荷谱,能真实地反映整个机群的平均使用情况。     

A new kind of magnetic targeting induction heating drug carrier and its physical and biological properties

Nano-carbon and iron composite―carbon-coated iron nanoparticles (CCINs) produced by carbon arc method can be used as a new kind of magnetic targeting induction heating drug carrier for cancer therapy. The structure and morphology of CCINs are studied by X-ray diffraction (XRD) and transmission electron microscope (TEM). Mossbauer spectra of these nanoparticles show that they contain only iron and carbon, without ferric carbide and ferric oxide. CCINs can be used as the magnetic drug carrier, with the effect...     

赖家剪切石英脉带型金矿地质特征

以赖家金矿床为实例,从矿床地质特征、矿床成因、矿化富集规律等方面阐述剪切石英脉带型金矿的基本地质特征,对赣东北分布广泛的剪切石英脉带型金矿的勘查与开发前景进行探讨.     

一种电涡流传感器的研制——光纤传输时分双信道低功耗调频式电涡流传感器

本文提出利用时分双信道传输测量与参考信号的原理,阐述抑制电涡流传感器探头温漂,提高测量精度的技术措施,讨论光纤远距离传输的防电磁干扰等特性,给出了温漂抑制、位移等性能指标的试验结果。