共查询到18条相似文献,搜索用时 78 毫秒
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主动控制式电磁液压悬置隔振性能研究 总被引:1,自引:0,他引:1
在原有液压悬置的基础上,提出一种利用电磁作动器为主动控制元件的主动悬置,研究了电磁作动器的频率特性,并建立了该悬置系统的力学及数学模型.选择滤波后的x-LMS算法作为控制算法,利用Matlab软件,仿真分析了该悬置的隔振性能.结果表明:在不同转速下,主动悬置系统都能使传递到车身的振动力大为减弱,在2秒钟时间内就降到无主动控制时的10%以下,说明采用主动控制后的悬置能有效隔离发动机的振动. 相似文献
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为探索磁控形状记忆合金(MSMA)可作为一种在振动控制领域中可推荐的新型智能驱动材料,在对其力学性能的研究中,给出其输出控制力的变化规律,继后自行研制MSMA作动器,确定MSMA材料的外形尺寸、变形恢复装置、磁路设计等重要的因素。建立平面直径为80m单层球面网壳结构,按照三种方案设置基于MSMA作动器的控制元件,并应用反应谱计算了竖向地震荷载作用下的响应,通过和无控结构的响应进行对比分析取得MSMA的控制效果。结果表明,MSMA主动控制元件对大跨网壳结构的振动控制效果很明显,是一种理想的智能驱动材料,有着广阔的应用前景。 相似文献
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为治疗感音神经性听力损伤,设计的中耳植入式助听器,近年来已成为国内外研究的热点。提出一种砧骨激励式中耳植入助听装置,设计时综合考虑植入位置、空间、手术过程等,并对加工出的装置进行了相关实验。该装置采用压电式作动器,结构简单,作动器产生的力能够高效地传送至听骨链。在设计过程中使用有限单元法(FEM)对装置的共振频率和输出位移进行预估,仿真及实验结果说明该作动器具有良好的动态响应特性,谐波失真度小于1 %,在6.9 Vrms电压驱动下能够提供相当于鼓膜处90 dB SPL激励的效果,可以激励镫骨产生足够的位移以补偿听力损失,是一款有效的助听装置。 相似文献
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提出一种同时含有被动和主动结构的新型汽车主动悬架,与现有主动悬架的最大不同点在于由电磁反力作动器产生的主动控制力仅作用于汽车非悬挂质量.首先,探讨电磁反力作动器的被动特性和以作动器作动力为PI反馈控制量的主动特性,作动器的主动特性显示较好的"天棚"阻尼特性.其次,建立对作动器作动力进行反馈控制的混合型主动悬架1/4车辆模型,并进行特性仿真试验.结果表明,采用作动器作动力进行反馈控制的新型主动悬架效果较好,能够同时改善悬架系统车轮环节共振高频段的平顺性、车轮接地性和减少悬架弹簧的变形. 相似文献
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传统的压电致动器,受限于压电致动的小行程,通常只能测量较小的范围。研发了一种电磁辅助压电致动器,同时具备电磁式致动器长行程与压电式致动器高分辨率的特点,该致动器包含可动件、导引槽、挠性件、电磁铁、压电元件以及控制电路。首先调整挠性可调预压装置并设定电磁铁电流,使得电磁致动力处于最大静摩擦力与动摩擦力之间;再利用压电组件所产生的微震动,控制可动件与导引槽之间的接触情况在静摩擦与动摩擦之间切换,从而完成长行程(10mm)且高分辨率(1.5μm)的往复运动。实验结果表明该致动器具备出色的定位能力。 相似文献
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《IEEE transactions on magnetics》2008,44(9):2181-2185
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《IEEE transactions on magnetics》2009,45(8):3064-3072
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Suzanne M. Kresta 《工程教育杂志》1998,87(1):7-9
Short demonstrations of basic fluid mechanics principles were developed for use in 50 minute seminar sessions, led by graduate student TA's. These have provided structured training for our TA's, lightened the load on our undergraduate lab facilities, and provided our students with visual, active learning opportunities. The demonstrations and handouts were developed by an undergraduate student as a summer project, and expanded on by successive TA's. The response from the students is best illustrated by the increase in seminar attendance from 30% to over 80%. 相似文献
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T. Nakajima 《Journal of Low Temperature Physics》2005,138(5-6):1039-1075
An alternative theory of beat, in which a variation of the intensity of a composite wave is formed from definite distinct waves of which more than two have different frequencies is constructed. It is applied to Pendelloesung beat (hereafter, abbreviated as PB) as an apt example. PB has been observed only in some light elements (below atomic number 32) by using rather hard X-rays up to 60 keV and above the room temperatures. These observations for the formation of PB support the view that the recoil energy loss plays the essentially important role in beat production by the superposition of the photons with the reduction of the momentum. The Bragg law for the reduction of the momentum by the recoil is derived based upon the corpuscular character of the light and the principle of the equipartition of the recoil energy over all the atoms in the crystal. The application of Braggs law, to the superposition of the expected value of the even or odd time multi-reflex photons (taken by the binomial distribution as stochastic events) forms two types of the transmitted or diffracted PB, respectively. The law predicts two types of prominently positive projecting peaks at half wave at even multiples of , and plus or minus projecting peaks at odd times of , according to the multiplicity factor of the reflection, exist as pulsations of bare PB from AM by cosec t in the basic bare envelope curve. It turns out that the AM effect of the binomial distribution on bare PB makes all of the peaks contract as if erased, and makes the intense collimated photon flux follow the Borrmann effect. It is proposed this review can be confirmed experimentally by testing the prediction that the integrated reflection intensity of PB fades into quantum PB as a limit near 0 K by a reduction of the recoil reflections due to the enhancement of the crystal rigidity with decreasing temperature. 相似文献