Adaptive vibration control of micro-cantilever beam with piezoelectric actuator in MEMS

This paper proposes a dynamical model and the governing equations of motion of the micro-cantilever beams based MEMS with piezoelectric actuator (PZT). The Rayleigh–Ritz method is used to reduce the order of the system and the state equations are presented in modal space. The first ten mode frequencies and mode shapes of the micro-cantilever beam with and without PZT are studied. The effects of PZT on the modal frequencies and shapes of the beam system can be ignored for the reason that the beam holds larger nature frequencies and Q values in micro-scale. A rational linearizing feedback controller with a high gain observer is designed to eliminate the unwanted deflection of the micro-cantilever beam system. The open-loop step response and the effects of situated places of PZT on the frequency responses of the system are discussed. Various frequency responses of the beam system, subject to different applied control voltages and feedback gains, are illustrated. The four resonances are well controlled, while the anti-resonance has little change. Computer simulations are provided to demonstrate the performance of the designed control scheme.     

Comparison of collocation strategies of sensor and actuator for vibration control

Some possible collocation strategies of sensor and actuator pairs for the application to active vibration control systems are analyzed, compared and discussed in this paper. This is becausea well-designed sensor — actuator collocation configuration can provide a simpler control algorithm with excellent performance and stability, especially when velocity feedback is adopted. As an ideal point collocation pair of a sensor and actuator shows high possibility in actual vibration control problems, the advantage of a collocated accelerometer — shaker pair is proven experimentally and discussed first. Then as a similar approach, a collocated piezosensor — piezoactuator pair is analyzed in depth with the in-plane motion coupling. Finally, two configurations of a practically collocated configuration with an accelerometer — piezoactuator pair and a non-overlapped collocated pair of a bimorph piezosensor — two bimorph piezoactuators are described in detail in terms of performance and stability with experimental results. Those two configurations are expected for the applications to more practical active control of vibration systems with the velocity feedback control scheme.     

应变式微型精密压电驱动器的一体化设计及其PID控制

基于有限元分析设计了一种利用应变片进行位移反馈的微型精密压电驱动器.该驱动器采用位移放大机构对微小应变进行放大,通过测量应变电桥的输出间接地测量出驱动器的微小位移.标定实验显示该传感器的精度为80 nm.虽然该应变反馈式压电驱动器是一种含有迟滞特性的复杂受控对象,但是在准静态条件下PID算法可以对其进行有效的闭环控制.分别进行了准静态的定位实验和跟踪实验,结果表明,PID控制算法对本驱动器的控制效果比较理想.在定位试验中,定位效果与开环相比有明显提高,定位误差不超过0.059 μm;单频正弦信号跟踪误差不超过0.085 μm;多频正弦信号跟踪误差不超过0.092 μm.实验证明了该方法在准静态条件下的有效性.     

基于压电执行器的切削振动主动控制实验研究

利用压电执行器,构造了切削振动主动控制实验系统并分析了该系统的控制机理;该系统根据以振抑振的思想,采用位移反馈策略对切削过程的振动行为进行干预,进而实施对振动的主动控制.从实验结果看,达到了明显的减振效果,该系统为将来制作更具商业前景的智能刀杆奠定了良好的基础.     

叠堆式压电陶瓷驱动器的复合控制

提出了逆Bouc-Wen前馈控制与反馈控制相结合的复合控制算法,用于改善压电陶瓷驱动器对目标轨迹的跟踪性能。建立了压电陶瓷驱动器的Bouc-Wen迟滞动力学模型,并用粒子群算法(PSO)对该模型的参数进行识别。基于Bouc-Wen迟滞模型,提出了逆Bouc-Wen前馈补偿控制。最后,为消除迟滞模型的不确定性,引入比例积分(PI)反馈控制,并与前馈补偿控制构成复合控制算法。建立了基于dSPACE实时系统的压电陶瓷驱动实验平台,迟滞实验结果表明:压电陶瓷的迟滞误差量几乎为0,线性度高达96.5%;目标轨迹跟踪实验结果表明:复合控制算法的最大跟踪误差为0.180 5μm,均方根(RMS-Root mean square)跟踪误差为0.055 4μm,跟踪精度达到了10-8 m。相比于开环控制、前馈控制及PI反馈控制,提出的复合控制算法能够基本消除压电陶瓷的迟滞非线性,同时具有很好的轨迹跟踪性能。     

Optimal control of random vibration in plate and shell structures with distributed piezoelectric components

The state covariance assignment (SCA) method of Skelton and associates has been extended to the optimal random vibration control of large-scale complicated shell structures with distributed piezoelectric components and under nonstationary random excitations. It provides a direct approach for achieving performance goals stated in terms of the root-mean-square (RMS) values which are common in many engineering system designs. The large-scale shell structures with distributed piezoelectric components of complicated geometrical configurations are approximated by the hybrid strain or mixed formulation based lower order triangular shell finite elements developed in the present investigation. Each of these shell finite elements has three nodes. Every node has seven degrees of freedom (dof) which include three translational, three rotational and one electric potential dof. These elements are better alternatives to those based on the displacement formulation and that hinged on the truly hybrid strain formulation in that they eliminate locking problems commonly associated with displacement based lower order shell finite elements. Computed results applying the proposed approach for a plate and a cylindrical shell structures with distributed piezoelectric components and under stationary random excitations are included to demonstrate its simplicity of use and efficiency of implementing the proposed approach.     

Assessment of shell theories for hybrid piezoelectric cylindrical shell under electromechanical load

The assessment of classical lamination shell theory and first-order shear deformation theory is presented for simply supported finite circular cylindrical hybrid shell with cross-ply composite laminate as elastic substrate under electromechanical static load. Navier-type solutions are obtained and used in threedimensional equilibrium equations and transverse strain—displacement relation to obtain transverse stress components and improved value of deflection. These solutions are assessed by comparison with the threedimensional solution. The error in the two-dimensional shell theories increases as the shell becomes thicker and it is more for the patch loads in comparison to the uniformly distributed and sinusoidal loads.     

Semi-active vibration control using piezoelectric actuators in smart structures

The piezoelectric materials, as the most widely used functional materials in smart structures, have many outstanding advantages for sensors and actuators, especially in vibration control, because of their excellent mechanical-electrical coupling characteristics and frequency response characteristics. Semi-active vibration control based on state switching and pulse switching has been receiving much attention over the past decade because of several advantages. Compared with standard passive piezoelectric damping, these new semi-passive techniques offer higher robustness. Compared with active damping systems, their implementation does not require any sophisticated signal processing systems or any bulky power amplifier. In this review article, the principles of the semi-active control methods based on switched shunt circuit, including state-switched method, synchronized switch damping techniques, and active control theorybased switching techniques, and their recent developments are introduced. Moreover, the future directions of research in semi-active control are also summarized.     

Beam vibration control using cellulose-based Electro-Active Paper sensor

Cellulose based Electro-Active Paper (EAPap) has recently shown a great potential as an environment-friendly smart material due to its biodegradability, biocompatibility and flexibility. Lots of studies have been conducted to investigate the basic smart characteristics of EAPap, but its application has not yet developed well. In this paper, the possibility of cellulose-based Electro-Active Paper (EAPap) as a piezoelectric sensor was investigated by the vibration control of the cantilevered beam. The EAPap sample was attached at the root of the cantilevered beam and used as a vibration sensor. The piezoceramic patch was also attached at the root of the beam and played as an actuator. The voltage output of EAPap showed exact dynamic characteristics of the cantilevered beam. The frequency bandwidth and quality factor of EAPap were similar to those of piezoceramic patch, which results EAPap has similar sensing capability of piezoceramic patch. To find the application of EAPap sensor, beam vibration control was performed. EAPap sensor output was considered as a position error of the cantilevered beam and a simple PID controller was designed to suppress the vibration of the beam. The EAPap sensor output provided clear time response of the beam. The controlled system showed good vibration control performance of the beam. The results provided that the piezoelectric characteristic of EAPap has a great potential as a sensor and also as a new smart material.     

Free vibration of transversely isotropic piezoelectric circular cylindrical panels

This paper presents an exact three-dimensional free vibration analysis of a transversely isotropic piezoelectric circular cylindrical panel. The general solution for coupled equations for piezoelectric media that was recently proposed by Ding et al. (Int. J. Solids Struct. 33 (1996) 2283) is employed. By using the variable separation method, three-dimensional exact solutions are obtained under several boundary conditions. Numerical results are finally presented and compared with available data in literature. The results show the non-dimensional frequencies of the piezoelectric panel are bigger than that of the non-piezoelectric one.     

Vortex-induced vibration control by micro actuator

The control of vortex-induced vibration of two side-by-side circular cylinders in a cross flow is carried out experimentally. One cylinder is elastically supported and the other is fix-supported at both ends. The two cylinders vibrate under the action of the unsteady flow-induced forces. A micro actuator is embedded on the surface of each cylinder to perturb the boundary layer. The spacing ratio is set at 1.2. The measurement shows that the structural vibration can be suppressed significantly when the reduced excitation frequency is around 2.655.     

尺蠖型压电驱动器的闭环控制研究

针对尺蠖型压电驱动器的输出特性,提出利用驱动电压与输出位移分段线性拟合曲线、逐步“搜索”驱动电压值,从而逼近目标位置的闭环控制方法,分析了控制方法的可行性。针对该方法,构建了闭环控制试验系统,对该方法进行了验证,试验结果表明：采用该方法可以实现对尺蠖型压电驱动器的闭环精确控制,相比于开环工作而言定位精度提高了14.4%,该方法具有控制精度较高、响应迅速等优点。     

压电陶瓷微位移器件控制模型的研究

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.     

Active vibration control of flexible cantilever beam using piezo actuator and Filtered-X LMS algorithm

This paper presents the active vibration control of a flexible cantilever beam. The cantilever beam was excited by steady-state sinusoidal and white noise point forces. The vibrational control system was implemented using one piezo ceramic actuator bonded on the beam and the adaptive controller based on the Filtered-X LMS algorithm. Control results indicated that a considerable vibrational reduction could be achieved in a few seconds. Experimental results, demonstrate the feasibility of active vibration control of the flexible cantilever beam based on piezo ceramic actuator and the Filtered-X LMS algorithm.     

Modeling and analysis of curved beams with debonded piezoelectric sensor/actuator patches

In this paper, a mathematical model for thin-walled curved beams with partially debonded piezoelectric actuator/sensor patches is presented for investigating the effect of debonding of the actuator/sensor on their open- and closed-loop behaviors. The actuator equations and the sensor equations of the curved beam in perfectly bonded and debonded regions are derived. In the perfect bonding region, the adhesive layer is modeled to carry constant peel and shear stresses; while in the debonding area, it is assumed that there is no peel and shear stress transfer between the host beam and the piezoelectric layer. Both displacement continuity and force equilibrium conditions are imposed at the interfaces between the bonded and debonded regions. Based on the model and the sensing equation of the sensor, a closed-loop vibration control for the curved beams is performed. To obtain the frequency response from the presented model, a solution scheme for solving the complex governing equations is given. Using this model and the solution scheme, the effects of the debonding of actuator and sensor patches on open- and closed-loop control are investigated through an example. The results show that edge debonding of the piezoelectric patch has a significant side effect on the closed-loop control of the curved beams.     

Robust observer-based OMF vibration control of flexible linkage mechanisms using piezoelectric films

Based on the state-space model of the flexible linkage mechanism equipped with piezoelectric films, a robust control methodology for actively suppressing the elastodynamic responses of the high-speed flexible linkage mechanism with linear structured time-varying parameter perturbations by employing an observer-based optimal model-following (OMF) controller is presented. The advantage of the proposed robust observer-based OMF control methodology is that it not only can avoid the problem of how to choose the appropriate weighting matrices in the quadratic cost function of the linear-quadratic/linear-quadratic-Gaussian (LQ/LQG) control method but also can make the controlled closed-loop system to have the specified system response characteristics. Besides, in order to guarantee that the designed observer-based OMF controller can make the controlled flexible linkage mechanism system to avoid the possibilities of both spillover-induced instability and time-varying-parameter-perturbation-induced instability, a robust stability criterion is also presented in this paper. The control method, presented in this paper, can not only make the controlled closed-loop system to have the specified system response characteristics, but also guarantee the controlled closed-loop system to have robust stability properties by using the proposed robust stability criterion; while those control methods reported recently do not have these above-mentioned merits. Finally, an active robust vibration control problem of a slider-crank mechanism is provided for illustrating the applicability of the proposed method.     

Dynamic analysis of laminated composite plates with piezoelectric sensor/actuator patches using the FSDT mesh-free method

This paper investigates the active control of laminated composite plates with piezoelectric sensor/actuator patches using an efficient mesh-free method, i.e. the element-free Galerkin (EFG) method. The formulation of the problem is based on the first-order shear deformation plate theory (FSDT) and the principle of virtual displacements. A simple control algorithm coupling the direct and converse piezoelectric effect is used to control the dynamic response of the laminate plate with distributed sensor/actuator patches through a closed control loop. Several example problems are studied to show the influence of stacking sequence and position of sensor/actuator patches on the dynamic responses of the laminate plate. These simulations provide us with the best location of the sensor/actuator patches for active control of the laminate plate.     

基于迟滞模型压电陶瓷跟踪控制方法

压电陶瓷存在迟滞现象,开环定位精度受到严重影响.本文提出一个能够精确描述迟滞现象的数学模型,通过实验发现压电陶瓷迟滞曲线由转换电压决定.提出基于这个迟滞模型的开环逆控制方法,压电陶瓷迟滞减少至1%以内,控制性能显著提高.     

基于压电式传感器的强夯振动测试分析(英文)

以山西大学城某新校区工程场地为例,对该场地强夯振动影响以及隔振沟的隔振效果进行了测试,对比了有无隔振沟工况下强夯振动对周围建筑物的影响,研究了不同夯击能下强夯振动在黄土地区填方地基中的衰减规律及如何确定强夯施工安全距离,提出了该场地的加速度和振源距的定量关系。通过与现有标准、规范的规定进行比较,分析得出了强夯施工振动对相邻建筑物影响的评价方法。监测结果表明,隔振沟在强夯施工中减振效果好,隔振沟对强夯振动水平速度的衰减幅度高达75%,且在6 000kN·m夯击能下,强夯安全距离为30m。     

基于移相控制的压电陶瓷驱动器设计

为解决开关式压电陶瓷驱器输出电流失真,纹波大等问题,设计了一套基于移相控制的压电陶瓷驱动器.主电路拓扑上采用多路半桥并联结合LCL滤波器电路,并采用移相控制,对拓扑和控制方法进行了仿真,通过了实验验证.实验结果表明:当负载电容为5μF,输入信号幅值为0～9.5V,频率在5kHz～2kHz范围内,驱动器能以良好的动态性能...