共查询到19条相似文献,搜索用时 68 毫秒
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根据桥式放大机构和平行四边形导向机构相结合设计了一种新型的垂直运动精密微定位平台。利用卡式定理推导了微定位平台的最大行程、刚度及放大比,利用拉格朗日方程推导了微定位平台的动力学模型及其固有频率。采用有限元仿真软件分析微定位平台的动静力学特性,并与理论分析结果进行对比,两者结果吻合良好。制造了微定位平台的原型样机,并进行了实验验证,实验结果表明:垂直运动精密微定位平台的行程可达112.9μm,闭环分辨率为10 nm,可以用于显微镜聚焦系统的微调等垂直定位精度较高的场合。 相似文献
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纳米尺度研究的发展对原子力显微镜的核心运动部件——纳米定位平台的定位精度与扫描速度提出了更高要求。针对平台运动耦合与谐振频率两项关键性能展开研究,设计了一种新型基于压电陶瓷驱动的二维高带宽低耦合纳米定位平台。结构设计上,首先提出高刚度并联解耦结构,然后基于内外侧柔性铰链刚度解耦假设,确立了高刚度低耦合设计方案。为进一步提升平台谐振频率,建立尺寸参数优化模型,以平台一阶谐振频率为优化目标进行优化设计。优化结果与有限元仿真结果误差小于6%,验证了设计方法的准确性。最后,加工样机并搭建实验系统。性能实验结果证明本文设计平台达到高带宽低耦合设计目标。平台性能与同类型现有平台相比,谐振频率提升20%,静态耦合降低80%,动态耦合降低30%,有助于原子力显微镜性能提升。 相似文献
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压电叠堆与柔性机构构成了微位移的基本形式,其行程与精度、输出力的矛盾需要结合应用要求对结构进行综合设计。针对所构建的超精密加工工具对六自由度微位移的需求,提出了一种以压电叠堆作为驱动元件,以柔性铰链和楔形机构作为传动机构的空间六自由度微位移定位平台。由于压电叠堆需要一定的预紧力才能发挥其微位移精度和输出力的优势,通过静力分析,得出了微位移平台各个自由度驱动力和位移输出关系的表达式及刚度表达式,对结构进行了优化。试验表明,各自由度的行程与分辨率如下:x,y,z方向的最大位移分别为7.48,8.33和4.14μm,分辨率为0.01μm;沿θ_x,θ_y,θ_z方向的最大旋转角度均为0.13°,分辨率为0.01°,满足所构建的超精密加工工具定位的精度要求。试验获得了微位移定位平台的激励电压与各自由度位移输出曲线,为平台的运动、定位控制提供了依据,也为柔性铰链机构和楔形机构在其他结构中的应用提供了理论依据和试验基础。 相似文献
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针对微操作与微装配任务对多维大范围精密定位运动的需求,采用粘滑驱动原理并结合压电柔顺机构设计二自由度、大行程、无耦合并联定位平台。利用桥式机构对内置压电驱动器进行位移放大,并与复合解耦结构配合构成二维柔顺驱动机构。交叉滚柱导轨则连接移动台与驱动机构,并通过预紧螺钉调整接触摩擦力,进而获得良好的粘滑运动特性。采用有限元法建立定位平台的静力学模型,并对位移放大倍数、应力和固有频率进行仿真分析。最后,搭建实验测试系统验证定位平台的输出性能。实验结果表明:在扫描驱动模式下,驱动电压为150 V时,平台x和y向的输出位移分别为63.84μm和62.61μm,耦合比为0.52%和0.59%,分辨率为6.5 nm和7.2 nm;在步进驱动模式下,驱动电压为120 V时,平台在x和y向的单步位移分别为47.31μm和47.20μm,耦合比为0.69%和0.73%,x正向、x反向、y正向和y反向的运动分辨率分别为0.49,0.47,0.47和0.42μm,最大垂直负载为50 N,设计的压电粘滑定位平台满足所需性能要求。 相似文献
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为了减小定位平台在X,Y方向的振动误差,实现高精度定位,搭建了宏微结合精密定位系统,由高性能直线电机驱动,气体静压导轨支撑和导向的宏动平台实现系统的大行程微米级定位,并由安装在宏动平台上的压电陶瓷驱动的微动平台对系统进行定位精度补偿。建立了定位系统机电耦合振动模型,采用比例积分微分(proportion integral derivative,简称PID)控制与最小节拍响应控制相结合的策略控制宏动平台,采用前馈-PID控制驱动微动平台,通过电容式微位移传感器实时检测定位系统终端的位置输出信号作为微动台的输入信号,实现定位系统的闭环反馈控制,达到宏动平台的振动误差实时补偿的目的。实验结果显示,所设计的微动补偿平台具有良好的动态特性,定位系统具有良好的误差实时补偿效果,针对X,Y向的振动范围由补偿前的4和3.5μm,补偿后减小到1μm的范围内。结果表明,所研究的振动误差补偿方法可以有效减小定位系统的振动误差,提高系统的定位精度。 相似文献
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This paper discusses the design and characterization of a new, single-axis, low-profile, piezo-driven vertical motion micropositioning stage for use in laser welding applications. A low-profile configuration is attained by mounting the piezo actuator horizontally and using a novel lever arrangement to transfer the horizontal motion of the actuator into the desired vertical motion. An analytical model for the static and dynamic behavior of the stage is presented, along with finite element (FE) modeling verification. A 200 μm motion-range stage was built, and tests show that the stage has a vertical stiffness of 6.0 N/μm and a resonance frequency of 364 Hz. The results are in very close agreement to those predicted by the model. 相似文献
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D. Zhang D.G. Chetwynd X. Liu Y. Tian 《International Journal of Mechanical Sciences》2006,48(12):1401-1408
A novel three degree of freedom numerically controlled micro-positioning table has been developed, optimized for applications such as improving the machining precision of precision grinders. The table consists of a moving platform, coupled to a base, three piezoelectric actuators and three capacitive sensors. An elastic structure with three notch-type flexure hinges both guides the platform and generates a preload for the piezoelectric actuators. The dimensions of the platform and flexure hinges and the position of flexure hinges are designed with the aid of finite element modeling to provide good stiffness with little bending deformation of the platform. The inverse model of the table is developed for numerical control. Experimental results are compared to the model predictions. The table has a natural frequency of 584 Hz, a resolution of 6 nm, an open loop control stiffness of 104 N/μm at the center of the moving platform and a closed loop control stiffness of 650 N/μm across the working area of the table. 相似文献
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压电陶瓷微位移器件控制模型的研究 总被引:8,自引:5,他引:8
从不同角度介绍了压电陶瓷微位移器件的两种控制模型.首先,借助于统计物理学分析,结合数学建模方法,建立了一个简单实用的压电陶瓷的迟滞数学模型.其次,借助于弹性体变形理论,介绍了压电/电致伸缩陶瓷的归一化控制模型,从理论上说明了采用电极化强度的方法可以有效减小迟滞的观点.并设计了两种实验系统,对两种控制模型进行了实验验证,实验结果表明,所建立的两种模型可有效减小压电陶瓷的迟滞非线性误差,提高压电陶瓷微位移的控制精度,有助于实现压电陶瓷驱动器的高精度开环微位移控制. 相似文献
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纳米级精密定位工作台研究 总被引:2,自引:0,他引:2
为实现压印设备的精密加工,应尽可能地提高工作台的定位精度.通过合理选材,设计出具有六自由度的工作台,并分析工作台定位精度的影响因素,通过误差分析,得到能够满足纳米级定位精度的工作台结构参数. 相似文献
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An investigation is undertaken to minimize residual vibrations associated with high-speed, low-amplitude machining processes. A numerically computed input signal allows the system to follow a desired output trajectory once an accurate dynamic model of the system is developed. Specific application of this method is focused on controlling tool motion while cutting micron depth surface features into a flat, rotating workpiece during a single-point diamond turning process. The synthesized input signal, applied open-loop, is used to eliminate transient surface features that are created by uncontrolled motion of the tool when it is plunged into the workpiece surface during the cutting process. Controlled and uncontrolled cuts are shown to demonstrate a significant improvement in resulting surface features. 相似文献
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A new 3-DOF Z-tilts micropositioning system using electromagnetic actuators and air bearings 总被引:1,自引:0,他引:1
A new 3-DOF Z-tilts (z, pitch, and roll motion) micropositioning system has been developed. It uses electromagnetic actuators and air bearings. An electromagnetic actuator produces an attraction force between the air bearing and the base plate. An air bearing has the role of suspension and guidance, with a clearance of several tens of micrometers in the z-direction. Therefore, this system has design features of guiding 3-DOF XYθ motion without limiting the plane motion and playing the role of a z-directional position actuator. With the control of current, the equilibrium position between magnetic attraction force and air bearing thrust force can be controlled with inherently infinite resolutions. The theoretical background of an electromagnetic actuator is explained. Then, an air bearing is analyzed in the point of z-directional positioning mechanism. The air bearing can be modeled as a second-order system with parameter variation—stiffness and damping vary with respect to the z-directional displacement. Therefore, a simple robust control algorithm is applied to improve the control performance. With the aid of robust control, this system provides 25 nm positioning resolution over the total range of 40 μm along the z-direction and, accordingly, 0.29 μrad resolution over the total range of 460 μrad in pitch and roll motion. 相似文献