共查询到17条相似文献,搜索用时 156 毫秒
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采用双晶片型压电执行器,对微夹钳进行了结构设计。根据压电陶瓷晶体变形的本质是极化及极化与表面电荷的关系,提出了基于积分电荷的钳指位移与夹持力的自感知方法。基于Jan G.Smits的压电悬臂梁静态模型,建立了钳指位移与夹持力的自感知数学模型。实验结果表明,静态或低频情况下,自感知的钳指位移同传感器获得的钳指位移具有很好的一致性;自感知方法所获得的夹持力(最大值为0.072N)大于微量电子天平的测量结果(最大值为0.052N),通过对自感知夹持力曲线进行相应的系数修正,自感知方法所获得的结果能很好地反映夹持力的真实大小。 相似文献
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采用双晶片型压电执行器,对微夹钳进行了结构设计。根据压电陶瓷晶体变形的本质是极化及极化与表面电荷的关系,提出了基于积分电荷的钳指位移与夹持力的自感知方法。基于Jan G.Smits的压电悬臂梁静态模型,建立了钳指位移与夹持力的自感知数学模型。实验结果表明,静态或低频情况下,自感知的钳指位移同传感器获得的钳指位移具有很好的一致性;自感知方法所获得的夹持力(最大值为0.072N)大于微量电子天平的测量结果(最大值为0.052N),通过对自感知夹持力曲线进行相应的系数修正,自感知方法所获得的结果能很好地反映夹持力的真实大小。 相似文献
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基于钳指可平动并能感知钳指位移与夹持力的要求,采用柔性放大机构对压电微夹钳进行了结构设计。基于ANSYS的压电耦合场分析技术,对压电微夹钳的静动态特性进行了分析表明,在200V的最大驱动电压下,钳指最大位移为233.9μm;在20V的阶跃驱动电压下,钳指的稳态位移为20.6μm,响应时间为0.1s;通过实验对压电微夹钳的静动态特性进行了测试,结果表明,在150 V的驱动电压下,钳指位移为78.4μm,夹持0.3mm×8mm微轴所产生的夹持力为9.2mN。 相似文献
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为提高压电微夹钳的操作精度,对其迟滞及蠕变误差进行补偿。基于压电材料迟滞曲线的非对称性,为提高微夹钳迟滞模型的精度,采用升回程分别建模的方法,建立了微夹钳的Prandtl-Ishlinskii(PI)迟滞模型,对迟滞误差进行了补偿。在综合考虑模型简单且具有较高精度的前提下,采用二阶惯性环节建立了微夹钳的蠕变模型,设计出无需求蠕变逆模型的补偿器,对蠕变误差进行了补偿。实验结果表明,在最大位移为120μm时,钳指位移的迟滞误差由补偿前的-11.8~10.7μm减小为-1.7~1.0μm;在900 s作用时间内,钳指位移的蠕变由补偿前的4μm几乎减小为0。 相似文献
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针对Prandtl-Ishlinskii(PI)模型要求被描述对象的初载曲线为凸函数,且模型与其逆模型都应关于算子中心对称的不足,通过引入死区算子对PI模型进行改进,以使其更好地描述具有非凸、非奇对称的压电陶瓷材料的迟滞特性。基于实测的压电微夹钳初载曲线,采用等分阈值方式,并通过使改进PI模型与实测初载曲线间的误差函数为最小,辨识出改进PI模型的参数,建立了压电微夹钳的迟滞模型。实验结果表明,在微夹钳15.2μm的最大位移范围内,模型误差的变化范围为-0.310~0.156μm,所建模型能很好地描述压电微夹钳的迟滞特性。 相似文献
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在结构的振动主动控制中,采用自感知执行器能减小结构的质量和体积,真正实现同位控制。设计了一种基于时分复用解耦系统的压电自感知执行器,使压电元件在传感时隙内作为测量振动的传感器,在执行时隙内作为控制振动的执行器,在放电时隙内释放积累的驱动电荷。设计了开关时序脉冲用于控制3个时隙的切换。基于LabVIEW软件平台,采用正位置反馈控制算法,将时分复用结构的压电自感知执行器用于悬臂梁1阶模态的振动主动控制,实验结果表明达到了良好的控制效果。 相似文献
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《Mechatronics》2023
To improve the operational flexibility of the piezoelectric microgripper, a new four-degree-of-freedom piezoelectric microgripper was designed and fabricated. The clamp fingers can move both along the clamping direction and along its vertical direction. Also, clamping experiments were conducted on a φ 300 μm × 20 mm micro-shaft. Based on the transverse inverse piezoelectric effect of two groups of vertical intersections, a new configuration of a four-degree-of-freedom piezoelectric micro-gripper is designed. It can produce micro-displacement along the clamping direction and vertical clamping direction simultaneously. According to the Euler-Bernoulli beam equation, the Lagrangian function method and Hamilton variational principle are used to model the four-degree-of-freedom piezoelectric micro-gripper. Then, based on the optimization of the geometric parameters of the fingers, the static and dynamic characteristics of the microgripper are analyzed by the finite element method. After that, the micro-gripper is made using lithography, gluing, and laser cutting. Finally, the piezoelectric microgripper's static and dynamic characteristics and the micro-shaft's clamping operation are tested by experiments. The experimental results show that the maximum displacement, response time, and natural frequency of the designed micro-gripper along and perpendicular to the clamping direction agree well with the finite element simulation. The designed microgripper exhibits a promising prospect in practical micromanipulation applications. 相似文献
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A smart microrobot on chip: design, identification, and control 总被引:1,自引:0,他引:1
A. Ferreira J. Agnus N. Chaillet J.-M. Breguet 《Mechatronics, IEEE/ASME Transactions on》2004,9(3):508-519
This paper deals with the microrobot on chip (MOC) concept which corresponds to the development of compact, inexpensive, and easily "plug and use" microrobotic components (as it is the usual case with electronic chips). A first prototype of a 6 degrees-of-freedom (DOF) piezoelectric micromanipulator MOC (MMOC) illustrates this concept: one scanning piezostage can move the gripper in x-y axes and the piezoelectric microgripper itself has two y-z DOF per finger. An embedded optical fiber connected to a CCD camera and a force self-sensing system allowing force feedback. The first prototype of MMOC is electrically and mechanically connected to a smartcard reader. In order to be able to manipulate safely and accurately micro-objects, a force/position closed-loop controller is proposed taking into account the static and dynamic behavior of the microgripper. Hysteresis compensation is obtained through Preisach model and then an adaptive inverse control method is employed for open-loop control strategy. Numerical and experimental results which validate the theoretical developments are presented. 相似文献
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《Mechatronics》2020
In this paper, a flexure-based piezoelectric actuated microgripper is presented for high precision micro/nano manipulation tasks. A new design of microgripper based on a three-stage displacement amplification mechanism is utilized to magnify the piezoelectric actuator displacement. A bridge-type mechanism with a two-sided output port is serially connected with two consecutive lever mechanisms. The output motion on both sides is linearized by parallelogram mechanisms. The single-notch and double-notch circular flexural hinges were used in lever, bridge-type and parallelogram configuration. The displacement amplification and transmission mechanisms are arranged symmetrically to obtain stability of shape and compact layout of the entire microgripper. Analytical modeling was performed to establish an input and output displacement relationship. Finite Element Analysis (FEA) method was utilized to evaluate the performance of the microgripper. The design parameters of the microgripper were optimized through FEA method. The simulation results of the FEA method were validated through experimentation on the established design. The experimental results show that the total displacement amplification ratio of the microgripper is 12.76. The microgripper jaws have a high precision positioning accuracy. The microgripper also achieves a high-level working mode frequency of 1044 Hz, which is capable of accommodating rapid transient responses. 相似文献
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This paper discusses the development of a displacement self-sensing estimator for a one degree of freedom (DOF) magnetically levitated system using the parameter estimation technique. Current demodulation technique is known to be capable of extracting the air gap length from the coil current with demodulation filters. However, one of its main disadvantages is that its output is a function of the air gap length and the duty cycle of the PWM amplifiers. It is therefore demonstrated here, through computer simulation and experimental investigation, that the self-sensing parameter estimation technique is capable of removing the variable duty cycle from the estimated output. It is composed of two identical demodulation filters, one coil inductance simulator and one PI convergence controller. Benefiting from the closed loop characteristics of the self-sensing parameter estimation, not only is the influence of the duty cycle removed, but the dynamic characteristics of the selfsensing system are also greatly enhanced. The design of the analogue circuitries implementing the algorithm of the self-sensing parameter estimator is described. Very good agreement in the static and dynamic calibrations of the estimator output is observed, when compared with a dial gauge and commercial eddy current probe. While the self-sensing active magnetic bearing (AMB) system is levitated, excellent signal tracking capability of the parameter estimator is noted. 相似文献
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为提高压电微动平台的位移输出精度,设计极点配置比例、积分、微分(PID)控制器对其进行控制。首先,在对压电执行器进行电学特性、机电特性分析的基础上,建立了压电执行器的数学模型;其次,在对平台进行受力分析、运动分析的基础上,建立了平台的动力学模型;然后,在保持平台极点虚部不变,且将系统闭环阻尼比取为1的情况下,将平台极点沿着平行于实轴的方向平移,设计出平台的PID反馈控制器;最后,实验验证了所设计控制器的有效性。实验结果表明,所设计的控制器可使平台具有较快的响应,在不考虑传感器噪声水平的情况下,平台在控制系统作用下的定位误差基本为0。 相似文献