工程试验检测中应变测量技术方法的试验研究

文章采用电阻应变计及磁感应变传感器对试验梁进行堆载试验,同时采用限元软件Midas FEA与ANSYS建立试验梁实体模型进行理论分析,结合实测数据与理论计算结果对应变(应力)测试方法中应该注意的问题提出建议,并分析了两种应变测试仪器的优劣与理论计算的差异。     

钢管内螺纹在漏磁检测中的影响

利用ansys软件,对钢管内螺纹在漏磁检测中带来的影响进行了仿真,叙述了计算的步骤,经过比较,得到了初步规律。     

Use of magnetic monitoring of vehicles for proactive strategy development

The proactive operational strategy in the transport system which is a parallel concept associated with the Intelligent Transportation System (ITS) seems to be modern and right direction of development. However, the basis for its operation is the “information” in the broad sense of the term, on the functioning of the transport system itself. As new technologies develop, there emerge new opportunities of putting to use a wide array of sensors which can deliver more complete traffic data but using complex matrix of sensors is often unjustified economically and confusing. The paper proposes use of magnetometers as an interesting alternative to pass the requirements of simplicity of application, minimum costs and maximum of acquired information. The process of obtaining the information requires analysis of the quantitative and qualitative changes of the magnetic field. The conducted analyses demonstrate the possibility of using the passive magnetic methods for the purpose of monitoring of vehicles. Placement of the magnetic sensor bear out an important issue and was also discussed. During the experimental research it has been proven that passive magnetic methods enable obtaining the information on the movement of a vehicle as well as on the vehicle itself. Estimations of such values as: vehicle’s moving direction, velocity, dimensions, clearance or mass having ferromagnetic properties and even the state of strain in a vehicle’s structure were confirmed in practice. In addition thanks to magneto-mechanical effects the theoretical possibility of assessing the stress occurring in the components of vehicles, which could be indicative of the volume of cargo carried. Moreover, the crash experiment showed the possibility of a collision detection using magnetic signal. The need for obtaining information increases from year to year, with information becoming the biggest asset which enables both development and effective use of the transport system. Included researches, proofs emerging opportunity of more extensive use of magnetic sensors and the passive magnetic methods which could be applied in the modern transportation system.     

船电设备电磁工程学的有限元法研究

论及船舶电工设备电磁工程学的基础理论——电磁场数值分析方法。提出了有限元原理的一种新的证明方法，其命题为：在磁阻连续或间断的区域中，磁场边值问题（非线性Ｐｏｉｓｓｏｎ方程）总是等价于条件变分问题（能量泛函取极小值）。     

磁浮系统中免疫专家PID控制器的改进

磁浮系统是一种典型的非线性、不稳定性开环系统。由于传统的比例-积分-微分（PID）控制器的参数是固定的,因此,控制系统无法兼顾悬浮系统的静态和动态性能。本文提出一种基于粒子群优化（PSO）算法的分段专家免疫PID控制器。该控制器先利用免疫PID控制器给出悬浮系统的阶跃响应曲线,再根据误差变化将该曲线划分为五个阶段,分段实现基于PSO算法的专家PID控制器。该控制器的优点是能够在悬浮系统工作时在线对PID参数进行调节,适应误差的不同变化,使控制器响应速度加快、调节精度提高,稳态性能变好,而且几乎没有超调和振荡。利用Matlab仿真,结果表明在相同精度要求下,该控制方法与单一的专家PID控制器的相比,磁浮控制系统的过渡时间变短,调节时间变短且过渡性能较好。     

电动车异步电动机控制方法研究

本文简要介绍了电动汽车异步电动机滑差角频率控制基本思想，系统的整体设计，电机矢量控制及其动态性能。     

节流式磁流体阻尼可调减震器的试验研究

本文介绍了以两种不同的磁流体作为工作液的节流式磁流体阻尼可调减震器的外特性试验，试验结果表明：其中ＢＨ－１磁流体的粘－磁性能和粘－温性有均优于０６－Ａ，满足了磁流体阻尼可调减震器的性能的要求，节流式磁流体阻尼可调减震器的示功图饱满，阻尼力变化显著，可调性能优良；其结构合理，为实用型磁流体阻尼可调减震器的研究奠定了良好的基础。     

船舶消除磁罗经自差的“人为航向法”

船舶磁罗经是重要的助航仪器,其剩余自差过大时（一般指50以上时）对船舶安全航行的影响应该引起高度重视。船舶磁罗经自差的主要来源是B／λ和C／λH等两个半圆白差力对罗盘磁针的作用,采用“人为航向法”消除磁罗经自差,对于中小型船舶来说是一种既简捷又实用的有效方法。     

金属转轴无线感应供电系统传输功率分析与结构优化

金属转轴扭矩、功率和形变等参数的在线检测在船舶等领域具有广泛的工程应用背景,对旋转机构的供电问题是影响检测可靠性和实用性的关键。传统的滑环和电池供电方式存在可靠性和寿命上的局限性。本文设计了一种用于金属转轴的侧置式感应供电系统,建立了磁场耦合单元的有限元分析模型,分析了互感耦合参数对系统传输功率和效率的影响,得出了在不同谐振拓扑结构下以最大传输功率为目标的最佳互感耦合参数,包括最佳的原副边线圈电感值及其比例等等关系,以及金属转轴与磁芯间距离。进一步分析了通过磁屏蔽技术和改进原边线圈绕制方式来提高金属转轴感应供电系统能量传输效率的可行性。最后通过实验验证了本文设计和分析方法的准确性和有效性。