Novel Approach for Fault Detection and Diagnosis of Sensors in Air Handling Units Using Wavelet Energy Entropy

A novel fault diagnosis method for sensors in air handling unit(AHU)using wavelet energy entropy was presented.Instead of directly comparing the numerous data under noise conditions,the wavelet energy entropy residual was compared in the proposed method.Three-level wavelet analysis was used to decompose the measurement data under both fault-free and faulty operation conditions.The concept of Shannon entropy was referred to define wavelet energy entropy of the wavelet coefficients.The sensor faults were diagnosed by comparing the deviation of the wavelet energy entropy of the measured signal and the estimated one with the preset threshold.Testing results showed that the wavelet energy entropy was sensitive to diagnose the biased faults.The wavelet energy entropy residuals exceed the threshold significantly when faults occur.In addition,the severer the faults were,the larger the residuals would be.The results prove that the proposed method is feasible and effective for the fault detection and diagnosis of the sensors.     

智能感应灯的设计

鉴于马路和教室等公共场所电能利用的不合理,设计并制作了智能感应灯。光线强弱采用光敏电阻判断。当周围环境较暗时,单片机根据微波传感器采集的是否有人信号智能控制灯具状态;而当周围环境较亮时,灯具自然熄灭。通过检测,此设计基本实现了灯具状态的智能控制,实现了电能的节约和合理利用。     

Electrical Power Assisted Steering for EVs and HEVs

Electrical power assisted steering (EPAS) is one of the key components, especially for electrical vehicle. It has attracted much attention for their advantages with respect to improved fuel economy and has been widely adopted as automotive power-steering equipment in recent years. EPS (electrical power steering) controllers contain MCU (microprocessor control unit) to implement the complex control algorithms. EPS control strategy development is the core technology of the whole system. To achieve the better performance of driving, both mechanical structures and electrical structures are totally designed as a whole. Model-based development is recommended to software design. There are several trends about EPS’ future, such as high power EPS development, high voltage EPS development and steering-by-wire technology.     

WKZ型无触点控制装置的研究

WKZ型无触点控制装置作为一种方向型无触点开关装置，实现了对被控电动机开关时间的连续调节。     

酚微生物传感器快速测定仪的研制

介绍一种以微生物膜电极为传感器的酚快速测定仪的结构和工作原理、技术性能和应用。仪器传感器的寿命可达１ａ以上；对酚类物质的线性响应范围为０．１～２０ｍｇ／Ｌ；响应时间为５～１０ｍｉｎ；与酚标准法对照同步测定废水样品，结果相关性良好，相对误差≤４％，是一种具有实用价值的分析仪器。     

Sequential Track Monitoring with Multiple 2-D Passive Sensors

1.INTSODUCTIONTargettrackinginamultitargetenvironmenthasreceivedagreatdealofattention.Todetermineorestimatethestatesoftheindividualtargetsinviewisachallengingproblem.Illnnlltiplesensorapplicationscenarios,trackmonitoringisafastmethodofdeterminingillcorrectreturn-to-trackandtrack--to-trackassignmellts.Whentrackingmultipletargetswitlltwo-dimensionalpassivesensors,falsereturn-to-trackassignments,targetmaneuvers,andfalsetrack-to-trackassignmentscanbedistinguishedbymonitoringthetrackingfilterr…     

对铁路接触网激光测量系统的探讨

本文叙述了测量系统的组成和测量原理,详细介绍了系统的数学模型和误差分析,并对铁路接触网主要测量参数的不确定度进行了分析和评定。与以往的测量方式相比,此测量系统可进行方位向旋转,从而对铁路接触网的测量参数更全、速度更快,测量精度可达±5mm。     

几种重要的气体传感器的特性分析

分析了几种常见的气体传感器——CO传感器、CO2传感器、H2传感器、CH4传感器和最新敏感材料的特性，指出稳定性，灵敏度，选择性以及抗腐蚀性是决定气体传感器性能的四项指标，在此基础上论述了气体传感器的广泛用途。     

大学物理实验中传感器综合实验教学改革初探

针对大学物理实验课程中传感器综合实验存在的问题,结合传感器综合实验的实验课程特点,对该部分的教学进行了一系列改革,旨在提高学员学习兴趣,培养学员综合能力和创新精神.     

用于变压器故障特征气体分析的气敏阵列传感系统

提出将气敏元件阵列技术和径向基函数神经网络（Ｒａｄｉａｌ Ｂａｓｉｓ ＦｕｎｃｔｉｏｎＮｅｕｒａｌＮｅｔｗｏｒｋ，ＲＢＦ－ＮＮ）相结合，以检测电力变压器油中的４种微量故障特征气体（１＊１０＾－６－１０＊１０＾－６级Ｈ２、Ｃ２Ｈ４、Ｃ２Ｈ２和５０＊１０＾－６级ＣＯ）。实验结果表明，与目前基于误差反向传播算法（ＥｒｒｏｒＢａｃｋ－ＰｒｏｐａｇａｔｉｏｎＡｌｇｏｒｔｈｍ，ＢＰ）神经网络的气体分析结果相比