29 research outputs found

    The development of online detecting system of five-axis CNC grinding machine for indexable insert

    Get PDF
    五轴可转位刀片磨床具有高速、高精的特点,为了使所磨的刀片符合精度要求,需要针对刀片的尺寸开发一种在线检测系统。本文所介绍的在线检测系统主要由两方面构成:一是在磨床数控系统中将测头伸缩时发出的电压信号转换为测量值;二是建立刀片尺寸的加工模型。在线检测系统通过调用系统的测量宏程序,获取刀片测量值,将此测量值输入到加工模型中,得到所加工刀片的指导尺寸。通过实验,得到了刀片的指导尺寸和测量时间,验证了此在线检测系统是可行并且可靠的。The five-axis CNC grinder of indexable insert is characterized by high-speed and high-precision.,in order to meet the accuracy requirements of grinding blades, needed an online detection system developed for the size of the blade.The online detection system described in this article consists of two aspects: First, the voltage signal that when the probe telescopics will be converted to the measured value; Second, establishing the process model of the blade size.The online detection system will get the blade measurements by calling the measure macro, then the measured value input into the process model, obtaining the guidance blade size.Through the experiment, verifying this online detection system is feasible and reliable by the obtained guidance blade size and the measuring time.国家“高档数控机床与基础制造装备”科技重大专项资助(2010ZX04001-162

    The Study on Target Detection Technique in Complex Sea Area

    No full text
    复杂海域的舰船、潜艇、蛙人等水下目标在运动过程中将不可避免的向周围辐射噪声,这些噪声中含有目标的重要特征信息,是声呐探测、目标识别和参数估计等等一系列工作的依据所在,对国家安全的意义非常重大。 然而,海洋环境具有多样性,是最复杂多变的无线信道,辐射噪声传输时通常会淹没在海洋环境噪声中,同时减震降噪技术的快速发展,使得本就非常微弱的辐射噪声信号更加难以捕捉和探测。因此,本文对复杂海域的目标探测问题展开了研究。 文章从海洋环境噪声入手,分析了海洋声信道的物理特性和传播特性,建立了镜像双扩展兼冲击噪声信道模型以及舰船、蛙人等水下目标辐射噪声模型,以混沌和随机共振等微弱信号检测技术为指导,结合实际...Underwater targets in complex sea area like ship, submarine and frogman will inevitably radiate noises to surrounded environment. These noises tend to contain significant target feature information, which is the foundation of a series of future work such as sonar detection, target identification and parameter estimation and is vital to our country's security. However, marine environment is va...学位:工学硕士院系专业:信息科学与技术学院_电磁场与微波技术学号:2312014115310

    a novel dynamic path optimization method for urban traffic networks

    No full text
    针对静态路径寻优方法中没有考虑到交通流随时间变化的问题,本文提出一种基于交通流量预测的路径寻优方法.首先,从实际交通路网本身的特点和人类对路网的 认识出发,构建以"道路"为基本元素的新型路网模型;其次,采用基于单变量时间序列的预测方法对路网上各路段未来一段时间内的道路交通流量进行预测,并根 据预测结果估计出行者在未来时段各路段上的交通代价;再次,通过估计的交通代价把车辆从起点到该路段时间内的道路交通变化状况融入改进A*算法的路径搜索 过程,从而建立一种高效的动态改进A*路径搜索算法;最后,实例表明预测交通流量与实际交通流量具有很好的拟合度,路径搜索结果能够对出行者起到诱导作用 ,提高出行者行驶效率.北京市优秀人才培养课题Aiming at the problem that traffic flow varying with the departure time has not been taken into account in static path optimization method,a path optimization method based on traffic flow prediction is proposed.First of all,a novel road-based model,based on the characteristics of traffic network and the human's understanding to the road traffic network,is constructed.Then,a prediction method based on single time series is adopted to obtain the future information of traffic flow of road sections,and transportation cost of travelers for each section is estimated by the forecast result.Next,the change of road traffic situation during the traveling from the origin to the destination is integrated into path search process of improved A?* algorithm by the estimated transportation cost,thus a high efficient dynamic improved A?* algorithm for path optimization is obtained.Finally,the path-search examples show that the predicted traffic flow and measured traffic flow can march well,thus the path searching result can guide travelers to improve their driving efficiency

    亚洲百合与东方百合远缘杂交亲和性

    No full text
    为得到花色丰富、带有芳香气味、抗性强的OA或AO(O为东方百合杂种系,A为亚洲百合杂种系)型优势杂种,采用常规杂交和切割柱头的方法进行杂交,结果 AO型的22个组合,仅有亚洲百合‘Pollyanna’×东方百合‘Sambuca’这一组合得到了4个膨大的蒴果和40粒有胚种子,结实率为0.27%;85个LA(LA为Longiflorum hybrids×Asiatic hybrids的杂交后代)×O型组合均未得到完全膨大的果实和有胚种子;而21个OA型组合,有7个组合得到了膨大的蒴果及有胚种子。采用切割柱头的方法也未提高结实率,说明其没能有效克服其远缘杂交的障碍。通过花粉管荧光显微观察发现,亚洲百合和东方百合花粉几乎均能在母本的柱头上萌发,并沿着花柱道伸长生长,最终达到子房进入胚珠,说明AO型或OA型远缘杂交的受精障碍主要为受精后障碍

    「特集 分子進化と統計科学」について

    Get PDF
    要旨なし分子進化と統計科学その他・前書き特集前書

    Space Docking for Reconfigurable Planetary Robot System

    No full text
    提出了以改装后的位置敏感传感器来引导机器人完成自动对接的方法,分析了具体工作原理。对可重构星球探测机器人在运动模式下完成对接的两种姿态进行了比较,分别用一般方法和改进后的规划方法计算出了对接工作空间,比较结果说明,机器人在运动模式下三角边着地有利于完成自动对接。对工作模式机器人在工作空间内的运动进行了静力学分析,分析结果表明,机器人在工作空间内可以自由运动。用VC和OpenGL搭建的平台对空间对接进行了仿真试验,试验结果验证了对接工作空间计算的正确性和完成空间自动对接的可能性
    corecore