基于多次压电效应的自感知执行器研究

Study of self-sensing actuators based on multiple piezoelectric effects

针对多次压电效应在同一压电体上双向可逆的特点,进行了多次压电效应实现压电执行器位移自感知的理论分析,由此阐明了压电体中多次逆与多次正效应的一一对应关系,以及介电电位移与多次正压电电位移分离的可行性.通过引入参考电容,采取电流积分与差分比例运算电路相结合的方式,得到一种较电桥电路解耦更易于在工程实际应用的方法.采用PZT-5叠堆执行器进行实验,验证了该解耦方法的正确性,同时得出了PZT-5叠堆二次正压电效应的线性系数,并进一步分析了三次压电效应对自感知执行器的分辨力和精度的影响,为压电自感知执行器性能的改善提供了一条新途径.

According to the characteristics of bidirectional and reversible effect of multiple piezoelectric effects in single piezoelectrics,theoretical analysis is carried on for multiple piezoelectric effects realizing displacement self-sensing of piezoelectric actuators.Thus,one to one correspondence between multiple converse and multiple direct piezoelectric effects is illustrated,and the feasibility of separating electric displacement caused by multiple direct piezoelectric effects from dielectric electric displacement is analyzed.Through a referenced capacitor combined with current integration and differential proportional operational circuit,a decoupling method which is easier for practical engineering application than electric bridge circuit is obtained.The experiments justified the method through a PZT-5stack actuator.Meanwhile,linear coefficient of the secondary direct piezoelectric effect is obtained for PZT-5stack.And the influence of tertiary piezoelectric effect on resolution and precision of piezoelectric self-sensing actuators is further analyzed.The study results can provide a new approach for the performance improvement of self-sensing actuators.