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基于单片机的红外超声室内定位系统 总被引:2,自引:0,他引:2
介绍一个以单片机为主控制单元、红外和超声传感器为测距工具、采用三个参考点的较高精度室内定位系统。其中重点说明系统测距的原理与实现,详细论述了一种新的测距方法,并通过实际的测距实验说明此方法的可行性与优点。 相似文献
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针对DV-Hop测距定位精度不准问题,提出基于DV-Hop测距修正的对数搜索(improved DV-Hop Ranging-based Logarithmic Search,DH-RLS)定位算法。DH-RLS算法利用锚节点间的真实距离信息估计跳距误差,修正跳距值,提高测距精度。利用质心定位算法估计未知节点的位置,并将此位置作为搜索起点,再利用搜索目标函数进行搜索,直至搜索到具有最小距离误差和的点。仿真数据表明,DH-RLS定位算法的归一化平均误差低于同类算法。通过对测距修正,降低了测距误差,同时利用搜索目标算法提高了定位精度。 相似文献
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针对传统相位式激光测距的不足,通过时间延迟链(TDC)结合相位测距的方式,设计了适用于大范围测距的高精度测距电路。应用该方式制作的电路,经过测试表明鉴相误差可控制到5 ps以下,实现了细时间间隔测量,相比于传统相位测距减少了算法难度及硬件处理资源。结合传统的多周期粗时间计数的方式,可以实现大范围远距离时间测量,具有实际使用价值。 相似文献
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刘星 《自动化与仪器仪表》2023,(3):162-167
针对铁路运输系统中输电线路故障测距和定位效果不佳的问题,提出基于FPGA的铁路电力行波故障定位系统装置。首先,基于暂态行波方法进行故障性质判断,并采用行波信号采集装置进行信号采集;然后利用模极大值算法进行故障特征提取,并通过模量波速时差分段法求出故障距离,从而实现电力行波故障准确定位。仿真结果表明,在铁路线路长度为60 km的状况下,本方法的绝对误差和相对误差分别控制在100 m和0.12%范围内,适应性极强;故障初相角仿真模拟中,故障初相角测距中的绝对误差始终低于80 m,测距误差较小。在不同故障类型测试中,提出故障测距方法的距离误差控制在100 m范围内,测距精度较高。最后在不同故障类型、故障距离和时间差的条件下,本装置的故障距离绝对误差均稳定在200 m范围内。由此可知,设计的故障测距定位装置具备操作性和稳定性,核心故障测距算法提高了电力行波故障定位精度,满足系统设计需求。 相似文献
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本文提出了一种基于信息融合的物体三维特征的提取方法,该方法利用两幅互相配准的三维测距图像和灰度图像,来提取多面体的三维特征。首先,通过分析灰度图像中的灰度变化及测距图像中的测距值变化,分别求取各自图像中物体的特征点及特征边;然后,利用两配准图像之间的对应关系,求得所有特征点、面与多边形在三维测距图像中的三维表示;接着,通过分析三维测距图像中所测得的各候选平面上特定点与边处的曲率及法向,验证候选平面 相似文献
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分布式系统安全性和可靠性检测的难点在于缺乏对系统脆性的动态评估. 针对这一难点, 提出一种新的概念脆性相对熵来衡量系统的脆性, 并给出评估方法. 利用脆性相对熵可以动态地衡量当前概率分布与系统崩溃概率分布之间的相对距离, 有效地评估系统当前状态, 并对系统脆性的概率风险加以定量分析. 仿真结果表明, 脆性相对熵可以衡量系统的脆性特征, 且越接近系统脆性分布, 脆性相对熵越小. 相似文献
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为实现基于投影仪和摄像机的结构光视觉系统连续扫描,需要计算投影仪投影的任意光平面与摄像机图像平面的空间位置关系,进而需要求取摄像机光心与投影仪光心之间的相对位置关系。求取摄像机的内参数,在标定板上选取四个角点作为特征点并利用摄像机内参数求取该四个特征点的外参数,从而知道四个特征点在摄像机坐标系中的坐标。利用投影仪自身参数求解特征点在投影仪坐标系中的坐标,从而计算出摄像机光心与投影仪光心之间的相对位置关系,实现结构光视觉标定。利用标定后的视觉系统,对标定板上的角点距离进行测量,最大相对误差为0.277%,表明该标定算法可以应用于基于投影仪和摄像机的结构光视觉系统。 相似文献
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一种远距离激光位移/挠度测量系统的设计 总被引:1,自引:0,他引:1
描述一种能够测量远处物体的位移或者挠度的远距离激光位移/挠度测量系统,并对该系统的结构、工作原理以及硬件和软件部分进行了详细的介绍,给出了实验测试结果.该系统由一个激光光源和一个线性测量系统组成.激光光束首先经过校准,然后聚焦在测量系统上来进行长距离精确测量.激光光源和测量系统之间的相对位移反映出了物体的位移或者挠度.该系统使用了一定的信号和图像处理方法来提高系统的精度和准确性,并且使用了长距离无线数字通信,提高了信号传输的稳定性、安全性,避免了长距离信号线布线的繁琐.该系统还使用单片机系统和8位数码管结合的方式进行数据计算和显示,不再依赖计算机,使测量系统具有更好的便携性.由于该测量系统具有高精度、高准确度的特点并且结构简单、成本低廉,将有良好的应用前景. 相似文献
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A cluster separation measure 总被引:20,自引:0,他引:20
Davies DL Bouldin DW 《IEEE transactions on pattern analysis and machine intelligence》1979,(2):224-227
A measure is presented which indicates the similarity of clusters which are assumed to have a data density which is a decreasing function of distance from a vector characteristic of the cluster. The measure can be used to infer the appropriateness of data partitions and can therefore be used to compare relative appropriateness of various divisions of the data. The measure does not depend on either the number of clusters analyzed nor the method of partitioning of the data and can be used to guide a cluster seeking algorithm. 相似文献
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This paper presents a fuzzy based leader‐follower flocking system. To maintain the distance between robots, we use a fuzzy logic controller to design a “force function” which is related to the relative distance between neighbours. The “force function” is used to control velocity of robots. To prove stability of the flocking system, we build a Hamilton function which is kinetic energy of the flocking system. Utilizing the LaSalle's invariance principle, we prove that the system is stable. Specially, we develop a flocking controller in local form. By using the local controller, the robots in the flocking system only need to know local information (relative distances and relative angles between neighbours). To evaluate performance of the flocking system, we simulate the flocking system tracking trajectories with different shapes. The local flocking algorithm is tested with three Pioneer robots. We use the SICK laser scanner to measure the relative distances and relative angles between neighbours. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society 相似文献
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一种微控制器的倒车雷达系统的设计 总被引:1,自引:1,他引:0
设计实现了一种倒车用超声波测距仪;系统以MC68HC908GP32型微控制器为核心进行模块化设计,采用4路探头进行超声波的发射和接收,通过通道选择电路对四路回波进行循环检测;回波信号经多重反馈带通滤波放大电路和过零比较电路后,触发定时器的输入捕捉中断,微控制器存储回波往返时间,经过温度校正和运算后送所测最短距离进行显示并报警;经调试该仪器能满足1.5m范围内的距离测距要求,测量"盲区"小于20 cm,具有高的精确度和可靠性;适当改进后可用于其它短距离测距要求的相关系统中. 相似文献
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Leo Liberti Carlile Lavor Antonio Mucherino Nelson Maculan 《International Transactions in Operational Research》2011,18(1):33-51
Distance geometry problems (DGP) arise from the need to position entities in the Euclidean K‐space given some of their respective distances. Entities may be atoms (molecular distance geometry), wireless sensors (sensor network localization), or abstract vertices of a graph (graph drawing). In the context of molecular distance geometry, the distances are usually known because of chemical properties and nuclear magnetic resonance experiments; sensor networks can estimate their relative distance by recording the power loss during a two‐way exchange; finally, when drawing graphs in two or three dimensions, the graph to be drawn is given, and therefore distances between vertices can be computed. DGPs involve a search in a continuous Euclidean space, but sometimes the problem structure helps reduce the search to a discrete set of points. In this paper we survey some continuous and discrete methods for solving some problems of molecular distance geometry. 相似文献
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One of the most significant threats of a national economy is the bankruptcy of its firms. Assessment of bankruptcy provides valuable information on which governments, investors and shareholders can base their financial decisions in order to prevent possible losses. Data envelopment analysis (DEA) has generally been used to assess the best relative efficiency of decision making units (DMUs). In this paper we modify directional distance formulation of DEA to assess bankruptcy. The method we develop is the most general non-oriented, non-radial directional distance model. This model measures worst relative efficiency within the range of zero to one. This is contrary to the best relative efficiencies of conventional DEA method. Our model locates worst performing DMUs and determines an inefficient frontier. This model simultaneously contracts output and expands input. This idea of bankruptcy assessment is in agreement with economic theory of bankruptcy. The study introduces a precise and comprehensive bankruptcy measure that could be used as an early warning system for bankruptcy assessment. Further, we apply our model to Information Technology (IT) and IT enabled services (ITES) companies in India as a case study. We find that Hewlett-Packard Globalsoft Ltd. has the least possibility of bankruptcy and Logix Microsystems has the greatest possibility of bankruptcy. 相似文献