基于光-压电的非接触式弹性圆环独立模态控制

在接近紫外波长的高能光束均匀照射下,极化的镧改性锆钛酸铅(PbLaZrTi,PLZT)铁电陶瓷具有反常的光生伏特效应,即在两极间会产生很高的电压。利用此电压信号来驱动层合于柔性板壳结构的压电作动器,可以实现对柔性板壳结构的非接触式控制。为实现弹性圆环的非接触式独立模态控制,利用模态展开技术及振型函数的正交性设计余弦状正交模态作动器,并利用PLZT产生的电压来驱动层合于圆环上的聚偏二氟乙烯(Polymeric polyvinylidene fluoride,PVDF)压电模态作动器。在控制策略上采用速度反馈的定光强控制,通过模态速度符号来调节压电作动器与PLZT的连接方向,以实现作动器产生控制力的正/负切换。采用Newmark-β法对弹性圆环在不同光强下的动态响应进行数值仿真分析。仿真结果表明,在PLZT产生的电压信号的驱动下,压电作动器对系统产生的驱动力随光照时间成指数倍增加,且光照强度越大控制效果越好。

Independent Modal Control of Circular Rings Based on Non-contact Hybrid Photostrictive/piezoelectric Acutation Mechanism

When a near ultravolet light illuminates on polarized PbLaZrTi(PLZT) materials,a large voltage can be generated between the electrodes due to the anomalous photovoltaic effect.The non-contact control of flexible shell can be realized using hybrid photovoltaic/piezoelectric actuation mechanism.In order to realize the non-contact independent modal control of circular rings,distributed cosine shaped modal actuators are designed based on the modal expantion method and the orthogonality of mode shape functions,and the polymeric polyvinylidene fluoride(PVDF) orthogonal modal actuators are driven by the voltage generated by PLZT.The velocity feedback and constant light control algorithm are used.In order to shift the actuator induced positive and negative control forces,the connecting direction of PLZT generators and PVDF actuators is regulated by the sign of modal velocity.The dynamic responses with various constant light intensities are numeric simulated by applying Newmark-β method.The simulation results indicate that the control force exponentially increases with the light illumination,and the control effectiveness can be improved by applying higher light intensity.