外穿式集中绕组激励旋转电磁场涡流无损检测系统

本文提出带集中式绕组可方便开合的新型探头设计,实现基于旋转电磁场涡流原理的管件外检测。通过COMSOL有限元模型研究了集中式绕组产生的旋转磁场特征及接收线圈参数对检测效果的影响,仿真结果表明集中式绕组可产生适于管件外壁缺陷检测的旋转电磁场,匝数较多、紧贴管道外壁并位于激励线圈端部的圆形线圈可更好地实现畸变信号拾取。构建了外穿式集中绕组激励旋转电磁场涡流无损检测系统,实现了对0.5 mm宽的周向与轴向裂纹检测,测试了系统对不同深度裂纹的识别能力,并利用位于管道外壁0到90°不同位置的裂纹验证了检测系统对裂纹周向定位能力,结果表明研发系统可进行任意方向裂纹的检测和周向定位,为连续管等管状构件的外检测提供一种新的方法。     

基于外穿式交流电磁场检测的钻杆轴向裂纹在役检测技术研究

钻杆是钻井过程中易受破坏的关键部件,在其服役过程中进行检测,对于减少钻具失效事故具有重要意义。针对钻杆在役检测的特点,提出一种新型外穿式交流电磁场检测方法,建立针对钻杆外表面轴向裂纹的外穿式交流电磁场检测有限元仿真模型,分析钻杆表面感应电磁场分布以及裂纹引起的电磁场畸变信号与裂纹尺寸关系,在此基础上提取裂纹识别特征信号,基于仿真模型分析激励线圈提离高度影响,设计开发井口钻杆外表面轴向裂纹在役检测系统,并进行试验测试,仿真和试验结果表明:外穿式交流电磁场检测探头所提取的钻杆轴向裂纹特征信号Bx和Bz分别反映裂纹深度和长度,具有定量识别能力;激励线圈提离高度可满足在役检测需要;外穿式交流电磁场检测系统利用周向阵列检测线圈可有效检测钻杆表面轴向裂纹。     

漏磁结合涡流的非铁磁性金属材料探伤研究

针对非铁磁性金属的内外壁损伤检测问题,设计了一种中低频的交流电磁场检测模型,对漏磁及涡流效应在交流电磁场检测中的耦合机制进行了分析,并制作电磁检测装置进行实验验证.基于COMSOL有限元仿真建立二维仿真模型,针对不同深度、不同大小的表面缺陷及埋深缺陷进行仿真检测,得到相应的检测线圈电压幅值、相位与缺陷深度的关系;以仿真...     

磁流变液的力觉反馈系统研究

提出一种基于磁流变液的力觉感知驱动装置,该装置具有内、外两个线圈,并且绕向相反,其中内部线圈缠绕在活塞外部,外部线圈则缠绕在缸体外部,通过内、外线圈磁场力的相互作用使其具有复位功能.根据磁流变液的特性及磁流变效应,结合线圈参数、结构参数和磁路设计等原则,给出了主动式磁流变阻尼器的结构设计模型,并建立了Bingham模型和修正的Bouc-wen模型的Simulink软件仿真,仿真结果验证了该装置结构设计的合理性,为其在力觉反馈系统中的应用提供了依据.     

基于Maxwell 3D高速磁浮列车间隙传感器检测线圈的分析设计

高速磁浮列车长定子轨道的齿槽结构,给悬浮间隙传感器的输出带来了齿槽效应,使磁浮车不能稳定运行.为了减小齿槽效应,利用Ansoft Maxwell 3D电磁场分析软件,对传统矩形检测线圈进行静态电磁特性仿真,并根据仿真得出的磁感应强度分布规律,设计了一种新的检测线圈结构,并通过仿真和实验验证了该线圈结构能有效减小齿槽效应.     

七沟道球笼式等速万向节受力及仿真分析

基于球笼式等速万向节钢球的受力模型,推导了一个钢球在星形套内沟道和钟形壳外沟道内运动时,沟道对钢球的周向力、沟道对钢球的法向接触力、保持架窗口对钢球的法向接触力的表达式。在此基础上,基于Herzt接触理论,对上述受力进行了Adams动力学验证。结果表明:仿真结果和理论计算基本吻合,七沟道球笼式等速万向节的周向力、法向接触力、钢球与星形套的摩擦力、与保持架的摩擦力均小于六沟道,并且随着摆角的变化而变化。     

基于光学散射原理的液体颗粒计数器的研制

开发了一种基于光学散射原理的液体颗粒计数器,分析了光学检测传感器的检测原理。设计了液体颗粒计数器系统的各个功能模块,进行了加工制作和装配;研制了一台完整的液体颗粒计数器,并进行了测试和分析。实验结果表明该仪器可以检测到纯水中0.5微米的乳胶球颗粒,研制出了国内首台商用化的亚微米液体颗粒计数器。     

插装式比例节流阀多目标遗传算法结构优化

提出了插装式比例节流阀先导级结构参数优化设计方法。在插装式比例节流阀非线性数学建模的基础上,通过仿真研究了先导级结构参数的改变对整阀动态特性的影响规律。为提高设计效率,充分考虑了优化过程中各参数的约束条件。提出了基于多目标遗传算法的插装式比例节流阀结构优化方法,以提高其动态特性。对优化前后的整阀动态特性进行了验证。研究结果表明:基于优化设计方法设计的整阀动态特性显著提高。     

基于电磁感应原理的球压试验压痕直径测试传感器研究

球压试验中传统的压痕测量方法由于难以准确区分压痕的真实边界,很容易导致测量结果出现较大偏差.基于电磁感应原理的球压试验压痕直径测试传感器,应用了互感线圈轴向距离发生变化会引起互感电压变化的原理.在球压试验中,当球压试验装置在重力作用下向下发生位移时,互感线圈轴向距离变大,从而引起互感电压发生变化.通过试验对位移量与互感电压建立数学模型,可对球压试验装置的向下位移量进行定标.应用基于电磁感应原理的新型传感器,可较为准确地测量出施压装置向下的位移量并计算出压痕直径,为球压试验的结果判定提供较为准确的依据.在实际研究中,通过理论分析与大量的试验数据相关结合,验证了应用该传感器进行球压试验压痕直径测试的可行性.     

基于DSP的大电机线圈内部缺陷无损检测系统

在电机制造厂的大型电机线圈绝缘体发空的检测中,采用的是人工的"听声法",人为因素较多.文中根据大型电机无内部缺陷线圈与有内部缺陷线圈声学特性的差异,设计出一种基于TMS320F2812 DSP的大型电机线圈无损检测系统.该系统包括了敲击系统、信号检测系统和DSP系统.通过对所设计的硬件电路进行模拟仿真和局部硬件测试,完成了硬件平台的开发,并开发了相应的应用软件,使系统基本上能实现线圈的内部缺陷在线无损检测.     

Application of dfb diode laser sensor to reacting flow (II) —liquid-gas 2-phase reacting flow—

Diode laser sensor is conducted to measure the gas temperature in the liquid-gas 2-phase counter flow flame. C₁₀H₂₂ and city gas were used as liquid fuel and gas fuel, respectively. Two vibrational overtones of H₂O were selected and measurements were carried out in the spray flame region stabilized the above gaseous premixed flame. The path-averaged temperature measurement using diode laser absorption method succeeded in the liquid fuel combustion environment regardless of droplets of wide range diameter. The path-averaged temperature measured in the post flame of liquid-gas 2-phase counter flow flame showed qualitative reliable results. The successful demonstration of time series temperature measurement in the liquid-gas 2-phase counter flow flame gave us motivation of trying to establish the effective control system in practical combustion system. These results demonstrated the ability of real-time feedback from combustor inside using the non-intrusive measurement as well as the possibility of application to practical combustion system. Failure case due to influence of spray flame was also discussed.     

APPLICATION OF CIRCUIT SIMULATION IN HARDWARE DESIGN FOR ELECTRONIC CONTROL HIGH PRESSURE COMMON-RAIL FUEL SYSTEM OF DIESEL ENGINE

By means of circuit simulation,hardware of electronic control unit (ECU) of high pressure common-rail electronic control fuel system for diesel engine is designed.According to the system requirements for hardware of ECU,signal-processing circuit of variable reluctance (VR) sensor,filter circuit for input signal,high voltage power circuit and driver and protection circuit of solenoid are simulated as emphases.Difficulties of wide scope of VR sensor output signal,efficiency of high voltage power and reliable and swift driver of solenoid are solved.The results of simulation show that the hardware meets the requirement of the fuel system.At the same time,circuit simulation can greatly increase quality of the design,alleviate design labor and shorten design time.     

基于模糊对向传播网络的PEMFC建模

质子交换膜燃料电池是由一种质子导体聚合电解膜构成的燃料电池,作为21世纪的绿色环保能源,对质子交换膜燃料电池进行输出特性研究有助于改善其性能,提高其工作效率。对于这种离散非线性系统,文章将神经网络和模糊控制技术相结合,设计出了一种以模糊神经网络自适应控制系统为核心的建模方法,它是由模糊对向传播（FCP）网络辨识器构成,仿真结果表明该模型可行,而且模型精度较高,从而为设计PEMFC实时控制系统奠定了一定的基础。     

六磁极差动式逆磁致伸缩效应应力传感器的设计

基于铁磁材料逆磁致伸缩效应的应力测试是一种新技术。目前对该技术的研究重点是如何提高它的测试灵敏度。涉及测试灵敏度的因素很多 ,其中最主要的因素就是传感器的合理设计。设计了一种六磁极差动式磁致伸缩效应应力传感器 ,并对试件进行了扭转和单向拉伸应力测试。通过与应变电测试验比较 ,验证了该传感器的基本磁测性能与理论分析的一致性 ,结果也表明这种传感器具有灵敏度高、结构简单以及可用于多种形式应力检测等特点。     

Car Fuel Economy Simulation Forecast Method Based on CVT Efficiencies Measured from Bench Test

Researchers face difficulties in studying the effects of driveline efficiency on car fuel economy via bench and road tests because of long working periods, high costs, and heavy workloads. To simplify the study process and shorten test cycles, a car fuel economy simulation forecast method for combining computer simulation forecasting with bench tests is proposed. Taking a continuously variable transmission (CVT) as the research object, a transmission efficiency model based on a bench test is constructed. An optimal economic variogram based on the original CVT variogram, the boundary conditions of vehicle performance, the road conditions and the driving behavior of the driver is generated in the Gear Shift Program (GSP)-Generation module in AVL Cruise. And on this basis a driveline simulation model that can calculate the fuel consumption based on the driveline data of a test car is built. The model is used to forecast fuel consumption and calculate real-time CVT efficiency under different conditions. Contrastive analyses on simulation results and real car drum test results are made. The largest error between simulation results and drum test results in driving cycles is 4.099%, which is 5.449% under constant velocity condition in driver control mode and 4.2% under constant velocity condition in automatic cruise mode. The results confirm the feasibility of the method and the good performance of the driveline simulation model in accurately forecasting fuel consumption. The method can efficiently investigate the effects of driveline efficiency on car fuel economy. Moreover, this research provides instruction for accurately forecasting fuel economy as well as references for studies on the effects of drivelines on car fuel economy.     

高精度超声波式飞机油量传感器设计

运用超声波测距原理设计了超声波式飞机燃油油量传感器.该传感器具有体积小、重量轻和精度高等优点,可以准确地、实时地测量飞机各油箱的燃油油量,有助于实现飞机燃油系统的精确测控.     

Car Fuel Economy Simulation Forecast Method Based on CVT Efficiencies Measured from Bench Test

Researchers face di culties in studying the e ects of driveline e ciency on car fuel economy via bench and road tests because of long working periods, high costs, and heavy workloads. To simplify the study process and shorten test cycles, a car fuel economy simulation forecast method for combining computer simulation forecasting with bench tests is proposed. Taking a continuously variable transmission(CVT) as the research object, a transmission e ?ciency model based on a bench test is constructed. An optimal economic variogram based on the original CVT vari?ogram, the boundary conditions of vehicle performance, the road conditions and the driving behavior of the driver is generated in the Gear Shift Program(GSP)?Generation module in AVL Cruise. And on this basis a driveline simulation model that can calculate the fuel consumption based on the driveline data of a test car is built. The model is used to forecast fuel consumption and calculate real?time CVT e ciency under di erent conditions. Contrastive analyses on simulation results and real car drum test results are made. The largest error between simulation results and drum test results in driving cycles is 4.099%, which is 5.449% under constant velocity condition in driver control mode and 4.2% under constant velocity condition in automatic cruise mode. The results confirm the feasibility of the method and the good performance of the driveline simulation model in accurately forecasting fuel consumption. The method can e ciently investigate the e ects of driveline e ciency on car fuel economy. Moreover, this research provides instruc?tion for accurately forecasting fuel economy as well as references for studies on the e ects of drivelines on car fuel economy.     

基于红外光电传感器的转速测量系统设计

该文设计了以AT89C51单片机为核心的一种基于红外光电传感器的智能转速测量系统。系统采用红外光电传感器采集信号,利用整形电路获取转数计数器的计数脉冲,通过单片机进行数据处理,最后用LED数码管对测量结果进行显示。研究结果表明,该系统硬件电路简单、精度高、抗干扰能力强、测量速度快。     

半差动环形角度传感器的研究

本文研制了适用于电控燃油系统的一种新型角度传感器,并对其结构、工作原理以及测量电路进行了分析。分析结果表明该传感器的特性能满足电控燃油系统性能的要求。     

缸内直喷汽油机冷启动燃烧与排放光学试验研究

结合光学单缸机和激光诱导荧光测量技术对直喷汽油机冷怠速工况缸内油气混合与燃烧过程进行了可视化试验研究。试验采用了屋脊形透明缸套和双侧激光,利用统计图像评估方法得到了缸内混合气浓度和燃烧火焰分布图像,通过缸压传感器和燃烧分析仪对燃烧稳定性进行了分析,采用废气分析仪和光学传感器分别对碳氢和碳烟排放进行了分析评估。研究表明：燃烧稳定时燃油与缸套碰壁是碳氢排放产生的主要原因,碳烟排放则主要由活塞顶部燃油碰壁造成;适当推迟第二次喷油时刻有利于点火时刻火花塞附近稳定浓混合气的形成,继而提高燃烧稳定性,同时减少碳氢排放,过迟喷射会导致碳烟明显增加,过早喷射会造成缸内失火,碳氢排放增加。