电致驱动微进给平台动态特性分析

在线性化的前提下,对电致驱动微进给平台各个组成部分进行了简化,建立了工作台动力学模型,分析了微位移工作台的动态特性,得出了其传递函数;并通过实验,对所建立的动力学模型及开环控制下平台的实际动态特性进行了验证.理论分析和实验结果的一致性说明理论分析的正确性及可靠性.     

用于二维精密定位工作台的微位移机构设计

微位移技术是精密机械与仪器的关键技术之一.本文介绍精密定位系统中的典型微位移机构,分析常用机构的特点及存在问题,并以平行板柔性铰链为基础,通过对其结构的优化,设计应用于扫描探针系统的二维定位工作台,并利用有限元方法对该工作台静态特性进行了仿真分析.     

二维解耦微位移工作台的设计和有限元分析

文中设计了一驱动器固定的二维解耦微位移工作台.根据所选微位移驱动器和微位移工作台空载达到最大位移时所需的驱动力,得到微位移工作台的理论设计刚度值,据此对微位移工作台进行设计,然后对其进行有限元计算,求得微位移工作台刚度的有限元计算值,刚度的理论值和有限元计算值吻合得很好,并且很好地解决了运动耦合问题,定位精度高.     

压电微位移台的动态迟滞建模及实验验证

为了提高压电微位移平台快速定位的精确度,建立了一种表征压电微位移平台驱动电压与输出位移关系的定位模型。考虑压电工作台在快速、大行程精确定位过程中会受压电陶瓷迟滞特性及本身动态特性的影响,本文采用BoucWen模型描述压电陶瓷迟滞特性,并结合压电工作台的动态特性进行共同建模,使模型同时体现压电工作台的动态特性与迟滞特性。为了验证模型的正确性,搭建了基于压电微位移平台和相关驱动器的实验设备对模型进行了实验验证,并进行了测控程序的二次开发。研究结果表明,与单纯的Bouc-Wen模型相比,提出模型在最大位移输出为40μm,输入电压频率为40Hz时的最大误差由3.04μm下降到了0.67μm,此时最大相对误差为1.68%。得到的结果验证了提出的模型可较好地模拟压电工作台的迟滞特性与动态特性,大大提高压电微位移平台在快速、大行程定位中的精确度。     

二维解耦微位移工作台的设计与有限元分析

微位移工作台在微机电系统、超精密加工和生物医学工程等领域有广泛的应用。设计了一种驱动器浮动的二维解耦微位移工作台。工作台采用双层柔性铰链杆对称一体化结构,消除了X、Y方向的耦合运动。推导了微位移工作台的理论刚度。为了验证此微位移工作台能够满足设计要求,采用有限元方法进行分析计算,有限元计算得到的微位移工作台刚度与微位移工作台的理论刚度吻合较好,并且通过有限元计算的结果验证了工作台在X、Y方向的运动无耦合。     

一种用于光纤F-P传感器的微纳米级微位移工作台的研究

标定光纤F-P传感器这种微纳米级位移传感器非常困难。分析常用的微位移技术优缺点，这里提出了一种基于弹性变形原理的工作台的设计方法。建立了工作台位移变形的数学模型，对其产生位移的误差进行了理论分析。在此基础上，实际设计并开发了实验系统，用德国heidenhaiyn光栅位移传感器对光纤F-P传感器进行了标定实验。大量的标定实验证明，该微位移工作台的不确定度为0．1μm。     

基于叠片式柔性铰链和压电陶瓷电动机的大行程直线驱动导轨设计

提出了一种叠片式柔性铰链导轨工作台,可以在保持柔性铰链微位移工作台高直线度的前提下,大幅度提高行程,同时还保持了柔性铰链微位移工作台无机械爬行现象的优点。采用压电陶瓷电动机作为叠片式柔性铰链工作台的驱动器,压电陶瓷电动机应用超声波驻波或行波驱动,具有定位精度高、行程大、频响高等优点,驱动分辨率可达20nm以下。     

压电陶瓷微位移驱动技术研究

精密异形非圆回转曲面的加工是精密加工中很重要的内容,微位移驱动技术是其中的关键技术.目前,微位移驱动元件种类很多,从控制精度和可操作性分析,压电陶瓷驱动有其独特的优点,但它的输出位移小,而且对于一定的驱动电源,输出幅度与输出频率负相关,这在很大程度上制约了它在高频响较大幅度位移输出场合的应用.为此首先对压电陶瓷的静、动态驱动特性进行了分析,并就特定PZT(Piezoelectric translator)进行了试验,在此基础上说明了该类微位移驱动有效的加工范围和改善其输出特性的措施,并提出了一种在较高频率下输出较大位移的方法,通过对系统进行数学建模进行了分析讨论,指出了其应用前景.     

三自由度微定位工作台的设计与特性分析

设计一种用于平面磨削主动控制的新型数控微定位工作台。该工作台采用三个安装在底座上的压电陶瓷 (PZT)驱动器驱动动平台 ,三个圆形凹槽弹性铰链构成的弹性环节实现对压电陶瓷驱动器的预紧。为了提高定位精度采用三个高精度的电容式位移传感器用来测量动平台的输出 ,从而形成闭环控制系统。采用有限元分析软件ANSYS对微定位工作台的静、动态特性进行了数值分析。     

VX380T数控加工中心工作台拓扑分析及多目标参数优化设计

为使VX380T数控加工中心工作台同时具有优越的静、动态性能和轻量化特点。利用拓扑分析的方法研究工作台截面的最佳载荷传递路径,依据拓扑分析结果设计了工作台的加强筋布局。将新结构工作台的整体质量和最大频响幅值为目标函数,以各加强筋的结构参数为设计变量,以原始工作台的静态性能和前3阶固有频率为约束条件进行多目标参数优化设计。对参数优化后工作台的质量、静动态性能进行对比分析,结果表明,其质量减轻了12.19%的同时,其静动态性能也得到了显著提高,证明了优化设计的可行性和有效性。     

基于微定位工作台的精密磨削过程动力学建模与误差补偿技术

为了消除传统平面磨床砂轮振动对加工精度的影响,提出了采用自行设计的纳米级微定位工作台进行在线动态补偿的方法。为了对平面磨床的动平台上安装有微定位工作台的新型机床磨削过程的特性进行研究,分析了磨头-砂轮-微定位工作台组成系统的动力学行为。运用模态综合理论和拉格朗日方程建立了磨削过程模态坐标下的动力学模型,并利用状态空间方法得到了磨床在模态坐标下振动响应的数值计算公式。由振型叠加原理,得到具有微定位工作台补偿装置的新型平面磨床在物理坐标下的响应。在此基础上分析了磨床系统的动态特性和补偿前后的加工精度。仿真结果表明,采用微定位工作台进行在线振动补偿,可有效地提高加工工件的表面质量。     

DEVELOPMENT OF A 3-DOF MICRO-POSITIONING WORKPIECE TABLE

In order to achieve active grinding control, a novel numerical control micropositioning workpiece table with a resolution of 6 nm has been developed. The table is driven by three piezoelectric actuators mounted on the base. An elastic structure with three half-notch flexure hinges is designed to apply preload to the piezoelectric actuators. The position of flexure hinges is also elaborately designed with consideration to reduce the bending deformation of the moving part. Three capacitive sensors are used to form close loop control system. Considering the table as a damped 3-DOF mass-spring system, the models of static and dynamic stiffness and error owing to the action of external forces have been established. In order to make the table have high resolution and positioning accuracy, an error compensation algorithm is implemented by using the established models. The experimental testing has been carried out to verify the performance of the workpiece table and the established models of the micropositionin     

二自由度微定位平台的研制

研制了一台压电陶瓷驱动和弹性铰链导向的一体化微定位平台,该微定位平台具有高刚度、高响应速度和高分辨率等优点。为了克服压电陶瓷驱动器伸长量较小的不足,采用杠杆放大机构增加微定位平台的位移输出。考虑驱动电路的影响,建立了微定位平台的机电耦合模型。通过试验研究了微定位平台的静动态特性,试验结果表明微定位平台的分辨率为5 nm,固有频率分别为143 Hz和180 Hz。该微定位平台可应用于纳米级的微定位。     

DEVELOPMENT OF A 3-DOF MICROOSITIONING WORKPIECE TABLE

In order to achieve active grinding control,a novel numerical control micropositioning workpiece table with a resolution of 6 nm has been developed.The table is driven by three piezoelectric actuators mounted on the base.An elastic structure with three half-notch flexure hinges is designed to apply preload to the piezoelectric actuators.The position of flexure hinges is also elaborately designed with consideration to reduce the bending deformation of the moving part.Three capacitive sensors are used to form close loop control system.Considering the table as a damped 3-DOF mass-spring system,the models of static and dynamic stiffness and error owing to the action of external forces have been established.In order to make the table have high resolution and positioning accuracy,an error compensation algorithm is implemented by using the established models.The experimental testing has been carried out to verify the performance of the workpiece table and the established models of the micropositioning workpieee table.     

亚微米级微位移工作台及其微计算机数字闭环控制系统

本文介绍一种单尾X-Y强性微动工作台及其微计算机数字闭环控制系统,采用自适应P-PID选择控制算法,达到了±0.03μm的位置控制精度和优良的动态品质.     

Observer-based sliding mode control with adaptive perturbation estimation for micropositioning actuators

Control of piezoelectric actuators is under the effects of hysteresis that could affect actuators micropositioning accuracy. In this paper a modified Prandtl-Ishlinskii (PI) operator and its inverse is utilized for both identification and real time compensation of the hysteresis effect. As a result, the actuator dynamic model would be transformed to the second order linear dynamic model. Considering the parametric uncertainties, PI estimation error and probably unmodeled dynamics, a variable structure controller coupled with adaptive perturbation estimation is proposed for trajectory tracking of the piezoelectric position. Considering the very noisy output of the actuator, a high-gain observer would estimate full states from the only measurable position trajectory. The stability of the controller in the presence of the estimated state is demonstrated with the Lyapunov criterion. Comparing to the widely used proportional-integral controller, the experimental results depicts that the proposed approach is greatly achieved in precisely tracking of multiple frequency trajectories.     

超精密切削用车床微量刀架系统研究

给出了一种新颖的微量车床刀架系统，该系统由PZT（piezolectrictransducer）驱动的X－Z二维微进给工作台和Y向的微调对刀装置组成。微量工作台的两个方向均采用三个弹性元件的非对称式新型结构，这种新结构使刀具安装面位于工作台的一个角落，方便了刀具的安装。Y向微调机构利用差分螺纹调节原理使粗精调集为一体，结构紧凑，调节方便。     

Design and characterization of a low-profile micropositioning stage

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.     

Precision X-Y microstagee with maneuverable kinematic coupling mechanism

Within modern manufacturing, there is a growing need for micropositioning units with very fine resolution and high repeatability. In this paper, a new micropositioning system based on the kinematic coupling is developed, and its unique path control is derived. The results show that such a system can provide the user with the ability to exploit the inherent position repeatability of the kinematic coupling, while maintaining full two-dimensional (2-D) motion control. More importantly, this mechanism is shown to have a mechanical amplification (leverage) that can allow for a significant increase in the effective positioning resolution of the position sensors employed by the actuators driving the kinematic coupling mechanism. This may drastically reduce the cost for achieving ultrahigh positioning resolution demanded by industry without using complicated and extremely expensive actuators and position sensors.