Classification and regression models of audio and vibration signals for machine state monitoring in precision machining systems

We present a data-driven method for monitoring machine status in manufacturing processes. Audio and vibration data from precision machining are used for inference in two operating scenarios: (a) variable machine health states (anomaly detection); and (b) settings of machine operation (state estimation). Audio and vibration signals are first processed through Fast Fourier Transform and Principal Component Analysis to extract transformed and informative features. These features are then used in the training of classification and regression models for machine state monitoring. Specifically, three classifiers (K-nearest neighbors, convolutional neural networks and support vector machines) and two regressors (support vector regression and neural network regression) were explored, in terms of their accuracy in machine state prediction. It is shown that the audio and vibration signals are sufficiently rich in information about the machine that 100% state classification accuracy could be accomplished. Data fusion was also explored, showing overall superior accuracy of data-driven regression models.     

基于云概率密度分布估计的大坝监测数据分析

大坝运行监测易受自然环境和监测条件影响，存在时间和空间上的变异性，监测数据具有不确定性。以云理论的随机性和不确定性分析方法为基础，并与空间数据辐射思想相结合，建立了云滴概率密度分布估计模型，然后导出云概率密度分布函数，依据样本监测数据推求母体空间数据的分布特征，并设计了基于逆向云算法云变换的计算程序。分析陆浑水库1979~1999年测压管监测数据和位移变形数据的云概率密度分布特征和云数字特征，得出了20 a来大坝的数据分布特征和运行状态。监测数据分析结果表明，云概率密度分布估计不仅能有效合理地分析大坝的运行状态，而且能够依据云数字特征来判断监测状态和监测环境的异常变化。      

Dissociating uncertainty responses and reinforcement signals in the comparative study of uncertainty monitoring.

Although researchers are exploring animals' capacity for monitoring their states of uncertainty, the use of some paradigms allows the criticism that animals map avoidance responses to error-causing stimuli not because of uncertainty monitored but because of feedback signals and stimulus aversion. The authors addressed this criticism with an uncertainty-monitoring task in which participants completed blocks of trials with feedback deferred so that they could not associate reinforcement signals to particular stimuli or stimulus-response pairs. Humans and 1 of 2 monkeys were able to make cognitive, decisional uncertainty responses that were independent of feedback or reinforcement history within a task. This finding unifies the comparative literature on uncertainty monitoring. The dissociation of performance from reinforcement has theoretical implications, and the deferred-feedback technique has many applications. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

井喷失控预警的远距离自动调焦控制研究

井喷失控是石油及天然气钻井、完井过程可能出现的灾难性事故，给人类生命财产造成严重伤害，污染环境，破坏地下资源以及在城市火灾、森林火灾、环境变化等监测工作中常需要远距离目标监测，为了获得高清晰的实时图像数据，需要实时自动调焦。通过系统分析远距离相机离焦的原因，建立了一个实时调焦数学模型，并以此为基础研制了一种新的对应距离和温度变化的离焦补偿控制系统。该系统采用微型步进电机实现智能控制，通过监测目标距离确定监测相机的初始焦距，以及环境温度变化的实时反馈实现焦距的实时控制，使相机可以在－40～125 ℃范围内获得清晰、稳定的远距离图像。该系统适用于井喷失控石油及天然气火灾、城市火灾、森林火灾、环境变化等远距离目标的实时监测。     

HART通信协议在汽油机速度测量和监控方面的应用

首先介绍了HART通信协议及他的优点，然后介绍了HART通信协议在汽油机测速方面的软件实现。该软件主要采用目前流行的VB编程语言。可设计出界面友好、功能强大的测量和监控软件。     

随机减量技术中周期激励的影响及消除方法

本文针对机械系统中通常存在确定性周期激励的事实 ,论证了周期干扰成分的存在对提取的随机减量特征信号的影响 ,基于数字滤波技术提出了一种从周期干扰环境中提取随机减量特征信号的简便方法。在回转机械稳定性监测中的应用实例表明本文提出的方法是有效的。     

宝珠寺重力坝安全监测设计及优化研究

大坝安全监测设计指导和控制着安全监测工作的进行，安全监测的效果和作用与监测设计质量有很大关系。通过对宝珠寺大级安全监测设计结果的研究，提出变形监测采用分段连续引张线法；渗流监测方面，测压管管径应小于50mm，且应根据不同测点量程，选用不同规格的仪器，以保证精度；应力监测有必要结合地质情况对监测设计进行优化；还应选择可能存在安全隐患和异常部位的测点进行自动化跟踪监测。     

无线电车载监测站的信号采集与通讯系统

本系统采用LabVIEW对无线电监测信号进行采集和处理．并开发用户界面。在Delphi平台上运用远程访问服务实现了无线电车载监测站与中心固定站的通讯。LabVIEW主程序对通讯子程序进行调用。     

Research and Development of a Network—Based Intelligent Maintenance Information System

A maintenance information system is an important part of equipment management.An intelli-gent maintenance information system(IMIS)is a synthesis of network technology,information technology and intelligent technology.The IMIS in used to finish flexible maintenance decision-making and fast main-tenance planning,which helps enterprises to effectively reduce maintenance cost and increase working effi-ciency.Because the IMIS integrates advanced technologies,its performance is better than a traditional one.The difference between an IMIS and a traditional maintenance information system,and the functions,struc-ture,important realizations,and application of an IMIS are discussed in this paper.