Determination of coordinates of a moving object by a concentrated seismic observation system

A signal processing algorithm for a passive seismic monitoring system is proposed and experimentally verified. This algorithm ensures effective detection and determination of the trajectory of a moving object. A concentrated receiver consisting of two geophones separated by a distance much smaller than the detected signal wavelength is used in experiments. Processing of experimental results shows that it is possible to determine not only the position of the seismically active object, but also the parameters of its motion.     

视觉伺服机器人系统的无标定目标运动估计

机器人视觉伺服系统是机器人领域一重要的研究方向。该文建立了三自由度平面机器人视觉伺服系统,着重研究在摄像机与机器人坐标系无标定的情况下对目标的运动估计,提出了一种无标定算法,采用Kalman滤波完成目标的运动估计,并验证了它的有效性。     

Tracing the motion of a large object in a fluidized bed using electrical capacitance tomography

An innovative method using electrical capacitance tomography (ECT) to trace a large object's motion on an air distributor in a fluidized bed is described here. The method fills the large object to be traced with a high permittivity material, and then a recalibration process is applied to reduce the nonlinearity caused by the large permittivity difference between the tracer particle and other fine particles in the measurement zone. The local dynamic threshold selection method is performed on the reconstructed image to locate the tracer particle's position.Static simulations and dynamic experiments testify that tracer particles with a diameter of one ninth of the measured cross-section and a fluidization velocity v/v_cr≤4.2 can be accurately located and traced. Employing this method to trace the motion of a spherical object in a bed shows that the fluidization velocity significantly influences the directional motion of a large, heavy object on an inclined air distributor.     

中央空调系统运转过程与对象特性的研究

为了制定中央空调系统的计算机控制方案,首先分析了中央空调系统的运转过程,研究了被控对象的动态特性,运用分解协调方法对系统整体过程按功能分解成为空调主机、冷冻泵、冷却泵和风机等4个子过程,对各子过程之间的关联进行了分析;给出了传递函数模型并规定了主要温度变量的约束范围,为控制规律提供了依据。     

A local method for loading a tested object during acoustic-emission diagnostics

A new acoustic-emission diagnostics method in which there is no need to load an entire structure has been studied. This method of monitoring (as a conventional acoustic-emission method) is based on making a deformation of the tested surface; however in this case, the load is applied to a preliminarily chosen site of the tested object in the most dangerous area.     

Comparative analysis of the efficiency of the Kalman filter and particle filter in solving the problem of object tracking in a seismic security system

Algorithms of filtration of trajectory points with the use of the Kalman filter and particle filter are studied from the viewpoint of object tracking in a seismic security system. A comparative analysis of the algorithms is performed in terms of the accuracy of determining the coordinates of the object trajectory points and computational complexity.     

基于传感器网络的动态车重测量系统设计

汽车动态测重是当前交通运输领域中的一个研究热点,本文提出了一种基于传感器网络的动态车重测量方案.该方案以无线传感器网络作为动态车重的测量前端,利用传感器网络节点数量多、分布广等优势,对动态车重参数进行初步采集.然后再利用传感器网络的数据融合和处理功能,对采集的数据进行处理,得到精确的车辆重量.该方案的关键是对采集的数据进行融合和处理.文中详细阐述了车辆动态重量参数的测量原理和数据的融合算法,包括对无线传感器网络采集到的多个原始数据之间的误差处理方法.     

基于电磁传感器的特殊环境高速运动目标速度测量

本文根据高速运动目标运动速度的测速原理,提出采用电磁传感器测速的方法。根据测试的要求和电磁感应原理,设计合适的电磁传感器。在分析问题的过程中,建立了磁化运动目标的磁偶极子模型和测速模型,分析运动目标在测速管中穿越电磁传感器时感应线圈产生的感应电动势和气体体积变化引起运动目标加速度的变化。最后通过仿真实验和高速运动目标在高温高压气体条件下运动的真实实验,来验证电磁传感器测速的可行性并分析影响测速精确度的因素。     

An efficient representative for object recognition in structural health monitoring

Structural health monitoring (SHM) program has been widely applied for damage assessment or monitoring the performances and the reliabilities of structures. Usually, structural damage is assessed by discriminating abnormal change from normal change in the structural dynamic behavior. This paper takes the SHM data from a real bridge as a study example and recognizes the trains which daily cross this bridge. The main aim of the current work is to improve the accuracy of structural damage detection. In this paper, symbolic data analysis (SDA) is introduced to extract hidden patterns from raw data, and principal component analysis (PCA) is performed to extract the most important properties of the signals and eliminate the influence of noise. A new representative is proposed in this paper and the recognition results obtained by the clustering algorithms with different representatives are compared. The results show that the new representative is robust to recognize the trains, and PCA is very useful to extract the properties of the signals as well as to reduce the influence of noise.     

Estimating the characteristics of piezoelectric transducers

A method for estimating the sensitivity of piezoelectric transducers (PETs) is proposed. It is based on normalizing the amplitude of the PET-exciting voltage and calculating the sensitivity with respect to a conventional unit level. The results obtained from measuring PETs produced by well-known foreign manufacturers and at our factory are presented. Attention is also given to measuring the duration of echo signals. The described technique for evaluating the characteristics of echo signals can also be applied to contact angle PETs. The results obtained and proposals put forward in this study can be considered when correcting the Russian Standard for measuring the PET characteristics.Translated from Defektoskopiya, Vol. 41, No. 1, 2005, pp. 20–28.Original Russian Text Copyright © 2005 by Senyutkin, Chineikina.     

Determining the distance to a ferromagnetic object with unknown magnetic characteristics

The possibilities for determining the distance to a ferromagnetic object with unknown magnetic characteristics by the measurement of its magnetic field at two spatial points are considered. An unconventional measurement device, which allows us to determine the distance to an object in real time, as well as an algorithm and software for the processing of measurement results with the computer-generated visualization of the parameters of a magnetic field induced by an object, were developed. The error in determining the distance to a sought object does not exceed 20.0%.     

Automatic recording of object motion by the speckle method in the terahertz range

Using a microbolometer detector array, we recorded real-time images of metallic and dielectric objects illuminated by monochromatic terahertz radiation, including those hidden behind an opaque barrier. It is shown that the characteristics of movement of rough objects dynamic can be retrieved from the dynamics of the speckle structure of their images in the terahertz range. An automatic processing algorithm for terahertz videos with recording of moving objects was developed and software implemented.     

水火管式工业锅炉给水微机控制系统的对象和调节特性

本文通过对给水微机控制系统的研究和现场试验，分析水火管式工业锅炉控制对象和系统的动态特性，并提出了合理的控制方案和优化参数。     

聚丙烯在线分析系统的研制

介绍了聚丙烯在线分析系统的结构、工作原理和应用方法.采用专利设计的采样预处理系统解决了气固混相样品的在线分析问题,而针对性开发的固体样品流通池保证的光谱的代表性和重复性.实验表明,采用该技术研制的聚丙烯在线分析系统能够在聚丙烯生产装置的粉料输送管线内自动取出气固混相的粉末样品,通过固体样品流通池采集到光谱并分析得到等规...     

一种波浪监测系统的硬件设计

海洋状态的实时信息,如海浪波高、方向和周期等海流参数,对于海岸保护、离岸海上活动如钻井平台或船只都具有重要的意义。文章介绍的WaMoS可用于遥控测量海况及表面海流参数。该系统可根据航海的X-波段雷达的信号进行交通控制和导航。     

虚拟心电监护系统设计

提出了一种基于LabVIEW的心电信号实时采集和分析系统。该系统采用自行设计的心电信号采集电路,实现心电数据的测量和数据转换,并利用LabVIEW开发环境完成心电数据的处理、分析和显示功能。     

Modal analysis of a multi-blade system undergoing rotational motion

A modeling method for the modal analysis of a multi-blade system undergoing rotational motion is presented in this paper. Blades are assumed as cantilever beams and the coupling stiffness which originates from the shroud flexibility is considered for the modeling. To obtain general conclusions from the numerical results, the equations of motion are transformed into a dimensionless form. Dimensionless parameters related to the angular speed, the hub radius, and the coupling stiffness are identified and the effects of the parameters on the modal characteristics of the system are investigated. It is shown that the coupling stiffness especially plays an important role to change the modal characteristics of the system. The range of critical angular speed is also obtained through the numerical analysis. This paper was recommended for publication in revised form by Associate Editor Seockhyun Kim Ha Seong Lim graduated from Department of Mechanical Engineering at Hanyang University in 2006 and received his Master’s degree in 2008. He is currently a technical engineer in STX Offshore & Shipbuilding Company, Seoul, Korea. Hong Hee Yoo graduated from the Department of Mechanical Design and Production Engineering at Seoul National University in 1980 and received his Master’s degree from the same department in 1982. He received his Ph.D. degree in 1989 from the Department of Mechanical Engineering and Applied Mechanics at the University of Michigan at Ann Arbor, U.S.A. He is currently a professor in the School of Mechanical Engineering in Hanyang University, Seoul, Korea.     

Friction characteristics of a ferritic-austenitic stainless steel during lubricated reciprocating motion

This report describes friction measurements of stainless steel against stainless steel during lubricated, small-amplitude reciprocating motion. The experimental investigation was divided into two parts. First, four different lubricants were evaluated using a response surface design, during which the average contact pressure and the sliding velocity were varied. Secondly, a 2⁴ factorial design with three replicate runs was performed. Here, the coefficient of friction in the initial stage and the duration of that stage were studied. The independent variables were the average contact pressure, sliding velocity, surface roughness and type of lubricant. In the early state (stage I), the value of the frictional force is controlled by plowing of the surfaces by asperities. In many lubricated contacts, this is the practically useful stage. The experimental results from the response surface design show that the duration of stage I depends on the type of lubricant. Adhesive wear can take place before 100 cycles. The factorial design indicates that the coefficient of friction in the initial stage is affected by the type of lubricant, surface roughness and the simultaneous change of the surface roughness and type of lubricant. The duration of the initial stage is affected by a change in the surface roughness, average contact pressure and a simultaneous change in average contact pressure and surface roughness. A two-parameter Weibull analysis was performed on the data from the factorial design. For the tests where lubricant no. 3 was used, a mixed distribution was indicated for the duration of stage I. This mixed distribution indicates that a weakest-link process as well as a healing process were involved.     

Integrated control chart system for time-between-events monitoring in a multistage manufacturing system

This article develops a control chart system consisting of several individual time-between-events (TBE) charts, each of which is used to monitor the time between successive events at different process stages in the manufacturing of a product in a multistage manufacturing system. The design algorithm considers all the TBE charts within a system in an integrative and optimal manner. Numerical studies show that the proposed design algorithm improves the performance characteristics of the chart system significantly and thus the product quality is further guaranteed. The proposed control chart system is easy to understand and operate; thus, the floor operators can utilize and understand it as easily as for the traditional system.