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超磁致伸缩执行器(GMA)具有驱动结构简单,响应快,输出力大等特点,在高性能电能-机械能与电能-液压能能量转换领域中具有广泛应用。该文分析了影响GMA位移输出的各个因素,首先介绍了GMA的工作原理及结构,随后对GMA进行电磁场仿真,比较不同线圈长度对GMA内部磁场强度分布的影响。最后搭建实验平台,分析了不同骨架材料、材料的不同处理方式及不同的预压力对GMA输出性能的影响。该文为设计高性能GMA提供参考准则,并总结出不同条件下GMA输出性能的优劣,为提高GMA性能及其结构优化提供可靠方案。 相似文献
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本文针对超磁致伸缩换能器磁路设计进行分析,包括驱动器磁路设计、磁路分析与设计、偏置磁场设计、激励线圈设置、超磁致伸缩棒的处理等,结合超磁致伸缩换能器发热分析,通过研究换能器磁场有限元、伸缩棒磁场有限元、伸缩换能器温度场有限元、样机与测试、测试结果分析等内容,目的在于提高超磁致伸缩换能器运行的稳定性,提升系统运行的可靠性。 相似文献
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超磁致伸缩致动器(GMA)是一种具有广阔应用前景的新型智能驱动元件。为方便GMA特性研究和控制实验的开展,设计了以DSP为核心的GMA测控系统。硬件方面,将上位机和DSP集成配置,可实现GMA的开环测试和闭环控制;软件方面,采用C++和Matlab混合编程编写上位机程序,实现上位机对测控过程的实时监控;控制策略方面,将GMA位移逆模型和单神经元PID算法写入DSP,提高GMA的控制精度。经实验表明,能够较好地完成GMA测控实验,有助于GMA的优化设计和控制策略的验证。 相似文献
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为满足超磁致伸缩驱动器(giant magnetostrictive actuator,简称GMA)对输入电流微步进、高精度和宽范围的要求,提出一种GMA程控电流源的设计方案。基于该微步进连续调整型电流源的电路原理,设计了微步进控制和恒流源控制电路,并通过电路仿真与实验测试验证设计方案的可行性。结果表明:该GMA程控电流源在电路仿真和实验测试中输出的电流精度分别达到0.5%和3%,电流步进值1.8mA,电流输出范围0A至7A。研究成果表明提出的程控恒流源的电路设计方案符合设计要求。 相似文献
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《Mechatronics》2000,10(4-5):457-466
Since the discovery and understanding of the magnetic properties of the rare earth elements, the transduction properties of magnetostrictive alloys has improved significantly over earlier nickel based alloys. Alongside the advances in permanent magnet technology, novel compounds containing terbium, dysprosium and iron are now available in commerical quantities. Given giant magnetostrictive strains (∼1200 ppm) coupled with a high transduction efficiency (>50%) and a large load bearing capability, all of which can be realised in modest magnetic fields, these new materials are now being employed in a variety of applications. High frequency generation is still dominated by piezoelectrics. However, the new materials have an excellent low frequency response, operate at low voltages and can withstand stress cycling. Non-linear and hysteretic behaviour has been controlled by state of the art digital control techniques and algorithms to such an extent that active vibration cancellation has been successfully demonstrated. 相似文献
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Based on the density functional theory combined with the nonequilibrium Green’s function formalism, the magnetic transport properties of dibenzotetraaza[14]annulene (DBTAA) and transition metal (TM)-DBTAA (TM = Fe and Co) sandwiched between two ferromagnetic zigzag-edge graphene nanoribbon electrodes are investigated. The results show that giant magnetoresistance, spin-filtering and spin-polarized current rectifying effects can be realized simultaneously in the DBTAA system by modulating the external magnetic field. Introducing of TM atoms has obvious effects on these spin-related effects. The mechanisms of these intriguing phenomena are proposed and these phenomena would be instructive in the design of high-performance magnetic nanodevices. 相似文献
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为了探究小功率激光模具自动修复技术,利用同轴视觉采集系统采集模具的裂纹图像,结合数字图像形态学细化处理识别裂纹位置信息,建立了数字图像处理流程,得到裂纹的轨迹信息,将裂纹轨迹信息矢量化后,经曲线拟合生成数控代码,导入到数控系统完成激光模具修复。裂纹图像经图像去噪增强、形态学细化等处理后,能够有效地得到裂纹中心线,将裂纹位图矢量化后转为DXF文件格式,通过CAM软件生成数控加工代码。结果表明,该方法加工精度达到0.0368mm,满足模具修复的精度要求;通过图像形态学细化处理技术可以实现激光模具自动修复。这对激光加工设备实现自动化和智能化提供了理论支持和技术基础。 相似文献
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《Progress in Quantum Electronics》2006,30(2-3):45-73
In this paper, we review the different configurations proposed for electromagnetic field optical sensing. Intrinsic and extrinsic optical fiber sensors for electric and magnetic field measurement are examined, including those realized jacketing the fiber by magnetostrictive, conductive, electrochromic and polymeric materials and those measuring induced strain by magnetostrictive, electrostrictive and piezoelectric transducers. Extrinsic optical fiber sensors exploiting magneto-optic, electro-optic and Joule effects are also presented.Moreover, integrated optical electric and magnetic field sensors in which microwave signal provided by an antenna modulates the optical signal generated by an optical source are reviewed. Finally, active and coupled resonators based on electric field sensors are investigated. 相似文献
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提出了一种用单片机控制光介质薄膜干涉滤波器探测光纤光栅波长偏移量的方法,并
构建了对外界应力实时检测的光纤光栅应力传感系统。实验中采用了一种超磁致伸缩材料(GMM) ,使光纤布拉格光栅( FBG)产生有效的B ragg波长偏移,用控制电流来调控FBG的应变和Bragg波长偏移;电流加到1A~5A之间时,反射峰的中心波长的偏移量随所加电流呈线性增加的趋势,偏移量达到1. 10nm ( 1551. 94nm~1553. 04nm) 。该系统具有对应力测量结果分辨率高、精度高等优点。 相似文献
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为解决因超磁致伸缩材料(GMM)磁致伸缩系数 对温度敏感而影响GMM-FBG光纤电流传 感器响应准确度的问题,研究了温度补偿的方法,构建了GMM磁场与温度的多场耦合模型, 进行温度传感实验、电流的通断实验、及不同磁场方向上的电流响应实验,设计了十字形传 感探头,利用垂直磁场方向的GMM的磁场不敏感性进行电流传感器的温度补偿,提高了GMM- F BG光纤电流传感器响应准确度。结果表明:垂直于磁场方向上的传感器中心波长值变化量为 ±0.05 pm,可忽略磁场的影响,温补后的拟合曲线与通断实验的拟 合曲线残差平方和为0.011,几乎完全重合, 可消除温度对GMM-FBG电流传感器的影响,使电流测量更加精确,并实 现电流与温度的同时测量,可满足当代电力系统的应用需求。 相似文献
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By applying the density functional theory and the nonequilibrium Green’s function formalism, we investigate the spin transport properties of a single-molecule magnet Mn(dmit)2 sandwiched between two ferromagnetic zigzag-edge graphene nanoribbon electrodes. The results show that the system can present large rectifying, giant magnetoresistance, spin-filtering and negative differential resistance effects with the help of magnetic field modulation. Moreover, an improved switching effect can also be realized by changing the orientation between planes of two dmit ligands. Therefore, the system will provide the possibilities for a multifunctional molecular device design. 相似文献
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Ru Huang Jinyan Wang Jin He Min Yu Xing Zhang Yangyuan Wang 《Microelectronics Reliability》2003,43(5):707-711
In this paper the hot carrier degradation behavior of the SOI dynamic-threshold-voltage nMOSFET’s (n-DTMOSFET’s) is investigated based on the forward gated-diode configuration. With peak diode current as an indicator, the hot carrier induced degradation of SOI n-DTMOSFET’s is compared with the corresponding SOI nMOSFET’s. Due to the connection of the gate and the body and thus the positive-biased source–body and drain–body junction, the SOI n-DTMOSFET’s exhibit lower peak diode current than the conventional counterparts, showing smaller generated defect density and thus lower hot carrier induced degradation. The generated defect distribution in SOI n-DTMOSFET is analyzed. It is shown that despite of the tied gate-body, the peak of the generated defect density tends to lie in the gate-to-drain overlap region. The defect distribution exerts different influences on the diode current of the long channel device and short channel device with different electric field. Moreover, even with the positive biased body, the generated defects in SOI DTMOSFT are more apt to flow to front interface rather than back interface, resulting in the more severe degradation of the front interface in SOI n-DTMOSFET’s. This gives the main flow direction of the generated defects. 相似文献