课程文献中心 更多>>

关键词： 水声传感器网络   鲸鱼优化算法   分簇路由  

摘要： 针对水声传感器网络(UASN)能耗效率问题,提出了一种基于改进鲸鱼优化算法的水声传感器网络分簇路由方法 .该方法能够有效平衡UASN中传感器节点的能量消耗,从而延长网络生命周期.同时能够根据簇头剩余能量等因素动态调整簇大小,平衡簇头负载.仿真结果表明:该方法相对其他典型能耗优化方法,能够有效降低整体网络能耗,延长网络生存时间.

关键词： 磁流体力学   方管流动   热电效应   对流换热  

摘要： 以液态金属锂和不锈钢为研究对象,采用磁流体力学相容守恒数值格式以及多区域耦合物理问题分区迭代算法,模拟部分导电管道内液态锂在有/无热电效应作用下的流动现象,磁场方向沿管道展向。模拟了较大雷诺数(Re=745.6)时,热电效应作用下液态金属在部分导电管道内的流动现象。研究发现,热电效应会在方管的4个角点处形成与流动方向相反的回流涡,该回流涡增大了中心区域的流速,并且强化了金属流体的对流换热能力。随着磁场强度增大,流动状态由非稳态变为稳态,说明磁阻尼效应逐渐占主导地位,热电效应的作用尺度由弱磁场下的整个流场逐渐收缩至强磁场下的流固壁面附近,速度与温度的耦合关系由弱磁场下的双向耦合转变为强磁场下的单向耦合。

关键词： 公路隧道   分布式光纤传感   温度探测   振动探测   振动信号  

摘要： 分布式光纤传感技术,包括温度测量和振动测量两个主要方向。将两根普通的单模光缆同时布设于公路隧道的沿线,实时监测隧道沿线机电设备所处环境的温度异常和振动异常,能够及时地发现机电系统在运行过程中出现的危险源,可实现隧道机电设备安全状态的连续实时监测,集测温与测振于一体的光纤传感系统,具有监测状态量在时间和空间连续、前端探测设备和后端处理设备安装布设简单、后期运行和维护所需的人力物力较少等应用优势。

关键词： 采煤工作面   自动调直系统   光纤捷联惯性导航  

摘要： 针对煤矿采煤井下作业时的定位实时性和精确性需要,开展了采煤工作面自动调直系统设计及试验。根据煤矿采煤作业的工作特点,设计了一种基于光纤惯导的自动调直系统。分析了综采面设备工况特性及定位需求,给出了工作流程、硬件组成、软件功能和自动调直算法等,并在国能所属矿井综采工作面进行了系统现场试验。试验结果表明,所设计的自动调直系统具有测量精度高、误差小等优点。该方案已经在煤炭领域具体项目中进行应用,证明其有很好的推广应用价值。

关键词： 机器视觉   缺陷检测   易拉罐罐盖   分类  

摘要： 易拉罐在饮料包装中被广泛应用,其罐盖在生产加工过程中可能会产生脏污、划痕、形变、拉环缺少等缺陷,为确保包装完好及食品安全,设计了一种基于机器视觉的易拉罐罐盖的缺陷检测系统.该检测系统硬件由机器视觉系统、传输分类系统两部分构成:选取合适的相机、镜头和光源等构建机器视觉成像系统实现高质量图像采集,选取合适的步进电机、步进驱动器、电缸、传感器等构建传输分类系统.运用LabVIEW、IMAQ VISION实现罐盖图像的采集与缺陷检测,运用LabVIEW和DAQmx实现对待测罐盖的传输,并依据缺陷检测结果对其进行分类,确保只有合格罐盖进入下道工序,从而提高生产效率,确保产品质量和食品安全.结果表明,所设计的系统能够满足设计要求,可为企业罐盖自动化检测提供参考,同时也可作为高校相关课程的实践项目,提升学生的工程实践能力.

关键词： Laser interference   Progressive scan CCD   Nanosecond pulsed laser   Crosstalk line   Spatial and temporal arrangement  

摘要： To investigate how a short-pulse laser impacts a charge coupled device (CCD), a laser with a 532 nm wavelength and an 8 ns pulse duration was employed to irradiate the CCD. Images formed by targeting representative CCD locations with a nanosecond pulse laser at various delay intervals were documented. Laser spots become visible in the resulting images if the CCD is exposed to the laser before the process of the readout transfer is completed. The count of saturated pixels in the laser spot, as the laser fluence rises, can be categorized into three parts. In addition, owing to the effect of channel barriers between adjacent vertical charge-transport channels, the length of the crosstalk line in the vertical direction is greater than that in the horizontal direction, and the difference becomes more obvious with increasing laser fluence. Moreover, the dimensions of the crosstalk lines were estimated theoretically. Besides, the experimental findings indicate that the spatial arrangement of the laser spot and the crosstalk line are influenced by two factors: the irradiation location and the delay duration. Nevertheless, the influences of the two elements on the spatial arrangement of the laser spot are separate, whereas their impacts on that of the crosstalk line are interconnected.

关键词： Charge-coupled devices   Imaging spectroscopy   X-ray imaging   Spectroscopy   X-rays   Image segmentation   Electrodes   Fermium   Frequency modulation   CCD cameras  

摘要： The Soft X-ray Imager (SXI) is an X-ray charge-coupled device (CCD) camera of the Xtend system onboard the X-Ray Imaging and Spectroscopy Mission (XRISM), which was successfully launched on September 7, 2023 (JST). During ground cooling tests of the CCDs in 2020/2021, using the flight-model detector housing, electronic boards, and a mechanical cooler, we encountered an unexpected issue. Anomalous charges appeared outside the imaging area of the CCDs and intruded into the imaging area, causing pulse heights to stick to the maximum value over a wide region. Although this issue has not occurred in subsequent tests or in orbit so far, it could seriously affect the imaging and spectroscopic performance of the SXI if it were to happen in the future. Through experiments with non-flight-model detector components, we successfully reproduced the issue and identified that the anomalous charges intrude via the potential structure created by the charge injection (CI) electrode at the top of the imaging area. To prevent anomalous charge intrusion and maintain imaging and spectroscopic performance that satisfies the requirements, even if this issue occurs in orbit, we developed a new CCD driving technique. This technique is different from the normal operation in terms of potential structure and its changes during imaging and CI. We report an overview of the anomalous charge issue, the related potential structures, the development of the new CCD driving technique to prevent the issue, the imaging and spectroscopic performance of the new technique, and the results of experiments to investigate the cause of anomalous charges.

关键词： 猪舍环境湿度   无线传感器网络   多速率测量   数据融合  

摘要： 在智能化养殖背景下，针对猪舍环境数据融合精度不高的问题，提出了一种基于无线传感器网络的新型数据融合算法。首先对猪舍环境数据进行卡尔曼滤波估计，然后将估计值和测量值发送到头节点进行一致性分析和加权数据融合，最后将头节点的集群数据融合值发送给汇聚节点，并基于一致性分析，在汇聚节点上对不同头节点的集群数据融合值进行加权数据融合。通过实例试验验证，该算法能在保证猪舍环境湿度测量精度的前提下，利用自适应多速率测量模式减少无线湿度传感器的数据传输量和能量消耗。