板材矫直机传动轴扭矩在线监测的研究与应用

针对邯钢中板厂板材矫直机主传动万向接轴频繁断裂问题,开发了采用焊接式全桥电阻应变片变形评估扭矩值的控制技术,增加主传动万向接轴扭矩监测装置,实现扭矩的实时监测.通过采集扭矩数据,分析研究万向接轴的损坏失效原因,制定合理的应对措施,有效避免了万向接轴断裂的再次发生.     

M-Copula函数在洪水遭遇中的应用研究

针对求解多变量情况下的设计水文特征值,采用M-Copula函数分析洪水遭遇问题,并采用适线法估计参数分析长江干流的设计洪峰流量.研究结果表明,M-Copula函数具有灵活性和应用范围广等特点,可更好地拟合两变量的相关关系,能更全面地描述设计洪水空间组成,在多变量水文频率分析中具有广泛应用前景.     

金属基体表面超疏水涂层材料的制备及应用 研究进展

金属材料因具有优异的综合力学性能,广泛应用于国防军工、工业装备制造等领域中。由于应用环境复杂多变,金属基体材料很容易受到外界环境的影响而发生表面腐蚀和结冰等问题,从而导致关键装备的功能显著下降甚至失效。为解决上述问题,国内外科研人员研发了在金属基体表面沉积超疏水涂层。由于超疏水涂层材料表面通常具有水接触角超过150°和滚动角低于10°的特殊润湿表面特性,要达到超疏水性能,一般需要具备微纳米粗糙结构和低表面能物质修饰两个条件。首先,介绍了制备超疏水涂层材料的常用方法,包括喷涂法、刻蚀法、模板法、沉积法等,并对主要优缺点进行了探讨。然后,在不同制备方法的基础上,进一步探讨了超疏水涂层在防结冰、防腐蚀、减阻、自清洁等领域中有效应用。最后,总结了近年来超疏水涂层材料技术的研究进展,并对未来超疏水涂层材料的研发方向进行了展望。这些研究成果为金属材料在复杂多变的应用环境中提供了更可靠的保护措施,有望提升关键装备的性能和寿命。     

基于引导滤波和快速共现滤波的红外和可见光图像融合

针对红外和可见光图像融合结果背景信息不足、对比度较低的问题,提出一种结合引导滤波和快速共现滤波的融合方法。首先,以高斯滤波将源图像分解为细节层和基础层。然后以去除值域滤波器、全局统计共现信息的方式简化共现滤波,形成快速共现滤波,再用其融合细节层;此外,引入窗口因子,用图像大小与窗口因子比值确定引导滤波窗口值,再用其融合基础层。实验结果表明该算法增加了图像背景细节,提高了人物与背景的对比度。主观和客观的实验分析验证了该算法的有效性。     

粉床型电子束增材制造W-3.5Nb合金孔洞缺陷及其形成机制

采用粉床型电子束增材制造(SEBM)技术制备了W-3.5Nb合金,研究了电子束线能量密度对W-3.5Nb合金孔洞缺陷形成的影响规律,分析了不同类型孔洞缺陷的形成原因.结果 表明:随着电子束线能量密度的升高,缺陷含量降低,当线能量密度升高到1.44 J/mm时,缺陷的体积含量最低为0.01％,继续增大线能量密度,缺陷的体...     

A model-based, semi-global segmentation approach for automatic 3-D point landmark localization in neuroimages

The existing differential approaches for localization of 3-D anatomic point landmarks in 3-D images are sensitive to noise and usually extract numerous spurious landmarks. The parametric model-based approaches are not practically usable for localization of landmarks that can not be modeled by simple parametric forms. Some dedicated methods using anatomic knowledge to identify particular landmarks are not general enough to cope with other landmarks. In this paper, we propose a model-based, semi-global segmentation approach to automatically localize 3-D point landmarks in neuroimages. To localize a landmark, the semi-global segmentation (meaning the segmentation of a part of the studied structure in a certain neighborhood of the landmark) is first achieved by an active surface model, and then the landmark is localized by analyzing the segmented part only. The joint use of global model-to-image registration, semi-global structure registration, active surface-based segmentation, and point-anchored surface registration makes our method robust to noise and shape variation. To evaluate the method, we apply it to the localization of ventricular landmarks including curvature extrema, centerline intersections, and terminal points. Experiments with 48 clinical and 18 simulated magnetic resonance (MR) volumetric images show that the proposed approach is able to localize these landmarks with an average accuracy of 1 mm (i.e., at the level of image resolution). We also illustrate the use of the proposed approach to cortical landmark identification and discuss its potential applications ranging from computer-aided radiology and surgery to atlas registration with scans.      

Flexible liquid metal coil prepared for electromagnetic energy harvesting and wireless charging

This paper reported a study on a flexible liquid metal coil (LMC) for electromagnetic collection from the transmission line for self-powered sensor and electromagnetic generation for wireless charging of cellular telephone. The room temperature liquid metal of Galinstan was perfused to elastic silicone tube, which is then terminated with gallium-plated copper wire. The as-prepared liquid metal wire can sustain stretching, twisting, and bending with large deformation, and has a good electrical contact stability with the external circuit. The LMC based magnetic energy harvester was then designed and demonstrated to collect the magnetic field energy induced by a wire carrying alternating current. The power of 260 mW was obtained for the wire carrying current of 10 A. The flexible toroidal inductor was fabricated and tested for magnetic energy harvesting. The flexible spiral-shaped LMC was also designed and demonstrated to power cellular telephone through wireless charging. The present study opens the way for further applications of elastic LMC in electromagnetic energy harvesting and charging.     

基于局部特征过滤的快速火焰图像识别方法

传统的基于物理信号的火焰识别方法易被外部环境干扰,且现有火焰图像特征提取方法对于火焰和场景的区分度较低,从而导致火焰种类或场景改变时识别精度降低。针对这一问题,提出一种基于局部特征过滤和极限学习机的快速火焰识别方法,将颜色空间信息引入尺度不变特征变换（SIFT）算法。首先,将视频文件转化成帧图像,利用SIFT算法对所有图像提取特征描述符;其次,通过火焰在颜色空间上的信息特性进一步过滤局部噪声特征点,并借助关键点词袋（BOK）方法,将特征描述符转换成对应的特征向量;最后放入极限学习机进行训练,从而快速得到火焰识别模型。在火焰公开数据集及真实火灾场景图像进行的实验结果表明：所提方法对不同场景和火焰类型均具有较高的识别率和较快的检测速度,实验识别精度达97%以上;对于包含4301张图片数据的测试集,模型识别时间仅需2.19 s;与基于信息熵、纹理特征、火焰蔓延率的支持向量机模型,基于SIFT、火焰颜色空间特性的支持向量机模型,基于SIFT的极限学习机模型三种方法相比,所提方法在测试集精度、模型构建时间上均占有优势。     

微纳操纵成像系统的线性自抗扰控制器设计

针对比例积分(PI)控制微纳操纵成像系统存在控制精度低、抗干扰能力弱等问题,提出了一种基于线性自抗扰的控制方法。该文分析了微纳操纵成像系统的结构及数学模型,并设计了线性自抗扰控制器,利用所得模型的参数,确定带模型信息的线性扩展状态观测器的部分参数和PI控制器的参数。在Matlab/Simulink中搭建控制器模型,并进行仿真实验的对比。结果表明,该研究与传统PI控制相比,具有控制精度高,抗扰能力强等特点,有效改善了系统的性能。     

A mobile dual-arm manipulation robot system for stocking and disposing of items in a convenience store by using universal vacuum grippers for grasping items

ABSTRACT

A mobile dual-arm robot with universal vacuum grippers (UVG) for performing stocking and disposing tasks was developed. The robot grasps items in the tasks by using UVGs whose surface adapts to the various shapes of the items. A selection algorithm that determines whether the robot should use one or both manipulators to arrange an item was also developed. A ‘reachable-grasp pose’ is defined as a pose in which the robot’s UVG can easily place an item with a target attitude if it grasps the item. By using the selection algorithm, the robot re-grasps the item by adopting the reachable-grasp pose if the two manipulators do not collide when one is in the current grasp pose and the other is in the reachable-grasp pose. The robot system won the third prize of the Future Convenience Store Challenge 2018. In experiments on stocking and disposing tasks, the robot system achieved success rates of 100% for the stocking task and 80% for the disposing task. We believe that the results of this study will help researchers to develop a robot system for not only the stocking and disposing tasks but also other tasks in convenience stores (like customer interaction).